In Niger, irrigated agriculture constitutes the main alternative for meeting family needs. It is within this framework that the state and its partners have adopted strategies to promote irrigated production sites. Thi...In Niger, irrigated agriculture constitutes the main alternative for meeting family needs. It is within this framework that the state and its partners have adopted strategies to promote irrigated production sites. This study was carried out on the Konni irrigated perimeter, the objective of which is to analyze the physical state of hydraulic infrastructures and their operation before the rehabilitation of the said perimeter. The methodology adopted consisted, first of all, of documentary research focused on data relating to this scope and our theme to properly guide the collection of data in the field. The field phase was then followed with an observation of hydraulic infrastructures one by one in order to assess their condition. Thus, the collected data was processed and analyzed. The results of this study show a notable deterioration of hydraulic infrastructure which affected the operating yield of the study area, with the development of barely 700 ha out of 1226 ha planned by the basic study for off-season production (57%). Bathymetric measurements showed that the volume of sediment that accumulated in the Zongo Dam is 1.2 million m3, which reduces its initial capacity from 12 million m3 to 10.8 million m3 after 43 years of service. The expansion joints of the feed canal are all in poor condition. 90% of the total length of the tertiary canals are degraded, 82.32% of the panels of the main canal C are degraded and 17.68% are cracked. All crossing structures are blocked between the RN1 and the Zongo dam. Based on this critical situation, it would be essential to consider rehabilitation work on all infrastructure in order to restore the hydraulic and even agronomic performance of the Konni irrigated area.展开更多
Diuron (N-(3,4-dichlorophenyl)-N,N-dimethylurea) is one among the booster biocides substituted tributyltin as an antifouling agent. It has continued to be used ever since, though little is known about their levels in ...Diuron (N-(3,4-dichlorophenyl)-N,N-dimethylurea) is one among the booster biocides substituted tributyltin as an antifouling agent. It has continued to be used ever since, though little is known about their levels in the maritime setting of Zanzibar. This paper details the occurrence and distribution of diuron around the coastline of Zanzibar Island. The reported concentrations of diuron in water ranged from Below Detection Limit to 1321.67 ± 52.3 ng/L at Bwawani. Majority of the sites showed levels above Environmental Risk Limit of 430 ng/L as proposed by the Dutch Authorities. The findings suggest the contamination is elevated especial in Harbor, Bwawani, Chapwani and even at Marine Protected Areas such Mnemba Island where the value of 620.33 ± 5.70 ng/L was recorded. The main possible sources of the contamination are cargo shipping, passenger speedboats, fishing, and tourism activities taking places in these areas. Therefore, future studies on the antifouling biocide diuron particularly on long term monitoring, chronic exposure, risk assessment, organisms’ responses and pollution models will add special value towards better understanding of the mechanisms and sustainable marine ecosystem health.展开更多
Research on habitat quality in ecologically vulnerable areas has gained attention due to mountain urbanization and climate change. However, the absence of comprehensive reviews limits a systematic understanding of hab...Research on habitat quality in ecologically vulnerable areas has gained attention due to mountain urbanization and climate change. However, the absence of comprehensive reviews limits a systematic understanding of habitat quality. This study investigates habitat quality research in ecologically vulnerable regions of China, drawing data from Web of Science and Scopus. Using CiteSpace software analyzes trends in publication volume, geographic distribution, journal outlets, research disciplines, and keyword co-occurrence. The findings identify two distinct research phases: an initial exploratory stage and a period of steady growth, with the Loess Plateau emerging as a primary focal region. Key journals, such as Ecological Indicators and Acta Ecologica Sinica, dominate the field, reflecting contributions from disciplines including environmental science and ecology. Research hotspots center on trade-offs between habitat quality and ecosystem services, driving factors of change, landscape pattern optimization, and simulation techniques. Future research should prioritize addressing the spatial heterogeneity of vulnerable regions, advancing methodological approaches, and enhancing uncertainty analyses in model parameterization. This study provides a critical foundation for addressing key scientific challenges and guiding future research, with implications for ecological security and sustainable development.展开更多
In the context of rapid urbanization,cities must leverage their unique advantages to enhance their competitiveness.It has become a prevalent practice to integrate Chinese cultural elements into a city’s brand identit...In the context of rapid urbanization,cities must leverage their unique advantages to enhance their competitiveness.It has become a prevalent practice to integrate Chinese cultural elements into a city’s brand identity,as well as to transform and elevate the existing landscape.This paper examines the landscape evolution of Nanchang Bayi Park(Baihuazhou)and the associated measures for its transformation and enhancement.The findings indicate that,from the perspective of urban visual art,these transformations significantly enhance the city’s aesthetic perception and more effectively address the needs of people.Consequently,this contributes to the ongoing improvement and development of the city’s brand image.By modifying the urban structure,enhancing the urban environment,upgrading infrastructure,and elevating the cultural levels within urban areas,the objective of transforming and upgrading urban landscapes can be realized.展开更多
The Tarim Basin has revealed numerous tight sandstone oil and gas reservoirs.The tidal fl at zone in the Shunbei area is currently in the detailed exploration stage,requiring a comprehensive description of the sand bo...The Tarim Basin has revealed numerous tight sandstone oil and gas reservoirs.The tidal fl at zone in the Shunbei area is currently in the detailed exploration stage,requiring a comprehensive description of the sand body distribution characteristics for rational exploration well deployment.However,using a single method for sand body prediction has yielded poor results.Seismic facies analysis can eff ectively predict the macro-development characteristics of sedimentary sand bodies but lacks the resolution to capture fi ne details.In contrast,single-well sedimentary facies analysis can describe detailed sand body development but struggles to reveal broader trends.Therefore,this study proposes a method that combines seismic facies analysis with single-well sedimentary microfacies analysis,using the lower section of the Kepingtage Formation in the Shunbei area as a case study.First,seismic facies were obtained through unsupervised vector quantization to control the macro-distribution characteristics of sand bodies,while principal component analysis(PCA)was applied to improve the depiction of fi ne sand body details from seismic attributes.Based on 3D seismic data,well-logging data,and geological interpretation results,a detailed structural interpretation was performed to establish a high-precision stratigraphic framework,thereby enhancing the accuracy of sand body prediction.Seismic facies analysis was then conducted to obtain the macro-distribution characteristics of the sand bodies.Subsequently,core data and logging curves from individual wells were used to clarify the vertical development characteristics of tidal channels and sandbars.Next,PCA was employed to select the seismic attributes most sensitive to sand bodies in diff erent sedimentary facies.Results indicate that RMS amplitude in the subtidal zone and instantaneous phase in the intertidal zone are the most sensitive to sand bodies.A comparative analysis of individual seismic attributes for sand body characterization revealed that facies-based delineation improved the accuracy of sand body identifi cation,eff ectively capturing their contours and shapes.This method,which integrates seismic facies,single-well sedimentary microfacies,and machine learning techniques,enhances the precision of sand body characterization and off ers a novel approach to sand body prediction.展开更多
This paper presents a standardised workflow for conducting hazard assessments of mass wasting processes in remote mountain areas with limited data.The methodology integrates geomorphological mapping and remote sensing...This paper presents a standardised workflow for conducting hazard assessments of mass wasting processes in remote mountain areas with limited data.The methodology integrates geomorphological mapping and remote sensing techniques and is adaptable to different national standards,thus ensuring its applicability in a variety of contexts.The principal objective is to guarantee the safety of mountainous regions,particularly in the vicinity of essential infrastructure,where the scope for implementing structural measures is restricted.The framework commences with comprehensive geomorphological mapping,which facilitates the identification of past hazardous processes and potential future hazards.New technologies,such as uncrewed aerial vehicles(UAVs),are employed to create high-resolution DEMs,which are particularly beneficial in regions with limited data availability.These models facilitate the assessment of potential hazards and inform decisions regarding protective measures.The utilisation of UAVs enhances the accuracy and efficiency of data collection,particularly in remote mountainous regions where alternative remotely sensed information may be unavailable.The integration of modern approaches into traditional hazard assessment methods allows for a comprehensive analysis of the spatial distribution of factors driving mass wasting processes.This workflow provides valuable insights that assist in the prioritisation of interventions and the optimisation of risk reduction in high mountainous areas.展开更多
Deforestation remains one of the most imminent threats to biodiversity in the tropics.As such,its causes and dynamics need to be studied and understood to put a halt to further forest loss and degradation.In tropical ...Deforestation remains one of the most imminent threats to biodiversity in the tropics.As such,its causes and dynamics need to be studied and understood to put a halt to further forest loss and degradation.In tropical countries such as Uganda,agricultural expansion and wood fuel demand are its leading drivers.While the establishment of protected areas is a key tool in conserving remaining forest biodiversity,results indicate that current management does not sufficiently provide alternatives to forest resources utilised by households and income provided from timber and non-timber forest products.Beyond safeguarding ecosystems,protected areas need to ensure the sustainable socioeconomic development of adjacent communities for effective biodiversity conservation–however,both management and research often neglect to consider all dimensions.In this study,we analysed five decades of forest cover change in the Mount Elgon region,Uganda,by conducting a remote sensing analysis of its protected areas using Landsat MSS and TM data from 1973-2023 in combination with literature and subsequent interview analysis to consider both the ecological and socioeconomic dimension.We applied a random forest approach to differentiate forest and non-forest areas and carried out a pixel-based change detection analysis to differentiate temporal and spatial changes.Throughout the study period of 50 years,forest cover has evolved dynamically within the boundaries of the protected areas of Mount Elgon.A significant decline was observed in both Mount Elgon National Park with a loss of-5.98%(-46.83km²)and Mount Elgon Biosphere Reserve with a loss of-14.96%(-134.33km²).Our results showcase a cycle of deforestation and afforestation that could be tied to a series of development initiatives,re-demarcation of boundaries,changes in management and recurring evictions.Overall,the results lead to the conclusion that the lack of sustainable and efficient management and funding has fostered the rate of deforestation and accelerated ecological degradation in the region,but that existing problems are also rooted in the land tenure history of the region.We recommend the proper implementation of participatory and long-term management approaches on the ground and to address the land rights issue to contribute to both socioeconomic wellbeing and sustainable conservation outcomes.展开更多
In order to identify the nutrient level and environmental quality of paddy fields in Wanchang area,and to provide scientific basis and technical support for planting rice in Wanchang area, the soil geochemicalsurvey w...In order to identify the nutrient level and environmental quality of paddy fields in Wanchang area,and to provide scientific basis and technical support for planting rice in Wanchang area, the soil geochemicalsurvey was carried out, 30 samples were collected from paddy soil in Wanchang area, and 20 elements(indicators) were analyzed. The characterization of the elemental content of soils in the study area was carriedout, and the geochemical level for soil nutrients, the geochemical level for the soil environment, and thecomprehensive geochemical level of soil quality were evaluated. The results showed that the average valuesof K content and pH of the soil in the study area were smaller than the background values of Jilin Province,and the average values of 18 elements including N, P, Ca, S, Pb, Zn etc. were bigger than the backgroundvalues of Jilin Province. The results of the evaluation of soil single element nutrient in the study area showedthat the available state nutrient levels of Mn, Zn, Cu, and K increased compared with the total amounts ofnutrients level, with Cu increasing the most;the available state nutrient level of N, P, B, and Mo decreasedcompared with the total amounts of nutrients level, with Mo decreasing the most. The comprehensive levelof soil nutrients geochemistry in paddy fields was mainly Level III (medium), accounting for 53.33%, andthe low abundance level was caused by the lack of P element;the comprehensive level of soil environmentalgeochemistry was mainly Level I (clean), accounting for 96.67%, with only slight pollution caused byCd. The comprehensive geochemical level of soil quality was mainly Level II, accounting for 66.67%.Suggestions were put forward for the rational utilization of soil resources in paddy fields in the study area.展开更多
AIM:To elucidate the neuropathological mechanisms underlying diabetic vitreous hemorrhage(DVH)and its correlation with clinical characteristics.METHODS:Twenty-one individuals with DVH(male/female 12/9;mean age 52.29&#...AIM:To elucidate the neuropathological mechanisms underlying diabetic vitreous hemorrhage(DVH)and its correlation with clinical characteristics.METHODS:Twenty-one individuals with DVH(male/female 12/9;mean age 52.29±11.66y)were selected,alongside 21 appropriately matched controls with diabetes mellitus(DM).Voxel-based morphometry(VBM)techniques were employed to identify aberrant functional regions in the brain.Receiver operating characteristic(ROC)curves were utilized for classification based on the average VBM values of the two groups,and Pearson correlation analysis was conducted to assess the relationship between average VBM values in distinct brain regions and clinical manifestations.RESULTS:Relative to the DM controls,DVH patients exhibited reduced VBM values in the right superior temporal pole,the right superior temporal gyrus,the right medial orbital frontal gyrus,and the left superior frontal gyrus.Furthermore,ROC curve analysis of these four brain regions in DVH patients demonstrated a high degree of accuracy,as indicated by the area under the curve.The average VBM value in each of these regions exhibited a negative correlation with both the duration of DVH and the score on the Hospital Anxiety and Depression Scale(HADS).CONCLUSION:Pathological alterations in four distinct brain regions are observed in patients with DVH,potentially reflecting neuropathological changes associated with this condition.展开更多
Cropland abandonment has been a widespread phenomenon in mountainous areas due to the increasing number of natural disasters and the massive migration of rural labor in the process of rapid urbanization.Land transfer ...Cropland abandonment has been a widespread phenomenon in mountainous areas due to the increasing number of natural disasters and the massive migration of rural labor in the process of rapid urbanization.Land transfer is a crucial prerequisite for ensuring food security and fostering rural revitalization.How to promote land transfer in mountainous areas remains a challenging but important task.Nevertheless,there is a dearth of research examining land transfers among farm households that specifically address mountainous regions,and the influence of grassroots governance and geographic location has not been thoroughly elucidated within this particular context.Based on 895household samples collected in Dabie Mountainous Area in China,this study employs binary and ordinal logistic regression models to provide a more comprehensive analysis on land transfers among rural households and the determinants,including the decision to transfer land,the existence of land transfer rents,the channel of land transfer,the duration of the transfer,the pre-transfer cultivation situation,and the level of satisfaction with the land transfer rent.The findings reveal that grassroots governance,geographic location,livelihood capital,and demographic factors significantly influence land transfers among rural households.Specifically,villagers'public participation positively affects land transfer participation(β=0.235,p<0.05),while the operation of village rules and regulations negatively impacts it(β=-0.296,p<0.05).Village cadre satisfaction positively influences both land transfer rent(β=0.274,p<0.05)and rent satisfaction(β=0.303,p<0.05).Improved civil relations in the village correlate with lower land transfer rent(β=-0.511,p<0.05),while a better social atmosphere is associated with higher satisfaction with transfer rent(β=0.575,p<0.01).Households at higher elevations tend to prefer government-mediated land transfers with longer durations.The distances to the township and county centers have contrasting effects on land transfer rent,but their impacts on participation in land transfer,choice of transfer channel,and duration are consistent.The study also found that different types of livelihood capital,as well as the demographic characteristics of households,significantly affect various aspects of land transfer.These empirical findings can inform policymaking to promote more efficient land transfers in mountainous region.展开更多
We build a computer program to reconstruct convex bodies using even L_(p)surface area measures for p≥1.Firstly,we transform the minimization problem Pi,which is equivalent to solving the even L_(p)Minkowski problem,i...We build a computer program to reconstruct convex bodies using even L_(p)surface area measures for p≥1.Firstly,we transform the minimization problem Pi,which is equivalent to solving the even L_(p)Minkowski problem,into a convex optimization problem P4 with a finite number of constraints.This transformation makes it suitable for computational resolution.Then,we prove that the approximate solutions obtained by solving the problem P4 converge to the theoretical solution when N and k are sufficiently large.Finally,based on the convex optimization problem P_(4),we provide an algorithm for reconstructing convex bodies from even L_(p)surface area measures,and present several examples implemented using MATLAB.展开更多
In the field of calculating the attack area of air-to-air missiles in modern air combat scenarios,the limitations of existing research,including real-time calculation,accuracy efficiency trade-off,and the absence of t...In the field of calculating the attack area of air-to-air missiles in modern air combat scenarios,the limitations of existing research,including real-time calculation,accuracy efficiency trade-off,and the absence of the three-dimensional attack area model,restrict their practical applications.To address these issues,an improved backtracking algorithm is proposed to improve calculation efficiency.A significant reduction in solution time and maintenance of accuracy in the three-dimensional attack area are achieved by using the proposed algorithm.Furthermore,the age-layered population structure genetic programming(ALPS-GP)algorithm is introduced to determine an analytical polynomial model of the three-dimensional attack area,considering real-time requirements.The accuracy of the polynomial model is enhanced through the coefficient correction using an improved gradient descent algorithm.The study reveals a remarkable combination of high accuracy and efficient real-time computation,with a mean error of 91.89 m using the analytical polynomial model of the three-dimensional attack area solved in just 10^(-4)s,thus meeting the requirements of real-time combat scenarios.展开更多
Investigating the ecological impact of land use change in the context of the construction of national water network project is crucial,as it is imperative for achieving the sustainable development goals of the nationa...Investigating the ecological impact of land use change in the context of the construction of national water network project is crucial,as it is imperative for achieving the sustainable development goals of the national water network and guaranteeing regional ecological stability.Using the Danjiangkou Reservoir Area(DRA),China as the study area,this paper first examined the spatiotemporal dynamics of natural landscape patterns and ecosystem service values(ESV)in the DRA from 2000 to 2018 and then investigated the spatial clustering characteristics of the ESV using spatial statistical analysis tools.Finally,the patch-generating land use simulation(PLUS)model was used to simulate the natural landscape and future changes in the ESV of the DRA from 2018 to 2028 under four different development scenarios:business as usual(BAU),economic development(ED),ecological protection(EP),and shoreline protection(SP).The results show that:during 2000-2018,the construction of water facilities had a significant impact on regional land use/land cover(LULC)change,with a 24830 ha increase in watershed area.ESV exhibited an increasing trend,with a significant and growing spatial clustering effect.The transformation of farmland to water bodies led to accelerated ESV growth,while the transformation of forest land to farmland led to a decrease in the ESV.Normalized difference vegetation index(NDVI)had the strongest effect on the ESV.ESV exhibited a continuous increase from 2018 to 2028 under all the simulation scenarios.The EP scenario had the greatest increase in ESV,while the ED scenario had the smallest increase.The findings suggest that projected land use patterns under different scenarios have varied impacts on ecosystem services(ESs)and that the management and planning of the DRA should balance social,economic,ecological,and security benefits.nomic,ecological,and security benefits.展开更多
A substantial reduction in groundwater level,exacerbated by coal mining activities,is intensifying water scarcity in western China’s ecologically fragile coal mining areas.China’s national strategic goal of achievin...A substantial reduction in groundwater level,exacerbated by coal mining activities,is intensifying water scarcity in western China’s ecologically fragile coal mining areas.China’s national strategic goal of achieving a carbon peak and carbon neutrality has made eco-friendly mining that prioritizes the protection and efficient use of water resources essential.Based on the resource characteristics of mine water and heat hazards,an intensive coal-water-thermal collaborative co-mining paradigm for the duration of the mining process is proposed.An integrated system for the production,supply,and storage of mining companion resources is achieved through technologies such as roof water inrush prevention and control,hydrothermal quality improvement,and deep-injection geological storage.An active preventive and control system achieved by adjusting the mining technology and a passive system centered on multiobjective drainage and grouting treatment are suggested,in accordance with the original geological characteristics and dynamic process of water inrush.By implementing advanced multi-objective drainage,specifically designed to address the“skylight-type”water inrush mode in the Yulin mining area of Shaanxi Province,a substantial reduction of 50%in water drillings and inflow was achieved,leading to stabilized water conditions that effectively ensure subsequent safe coal mining.An integrated-energy complementary model that incorporates the clean production concept of heat utilization is also proposed.The findings indicate a potential saving of 8419 t of standard coal by using water and air heat as an alternative heating source for the Xiaojihan coalmine,resulting in an impressive energy conservation of 50.2%and a notable 24.2%reduction in carbon emissions.The ultra-deep sustained water injection of 100 m^(3)·h^(-1)in a single well would not rupture the formation or cause water leakage,and 7.87×10^(5)t of mine water could be effectively stored in the Liujiagou Formation,presenting a viable method for mine-water management in the Ordos Basin and providing insights for green and low-carbon mining.展开更多
At present,there is not much research on mid-story isolated structures in mountainous areas.In this study,a model of a mid-story isolated structure considering soil-structure interaction(SSI)in mountainous areas is es...At present,there is not much research on mid-story isolated structures in mountainous areas.In this study,a model of a mid-story isolated structure considering soil-structure interaction(SSI)in mountainous areas is established along with a model that does not consider SSI.Eight long-period earthquake waves and two ordinary earthquake waves are selected as inputs for the dynamic time history analysis of the structure.The results show that the seismic response of a mid-story isolated structure considering SSI in mountainous areas can be amplified when compared with a structure that does not consider SSI.The structure response under long-period earthquakes is larger than that of ordinary earthquakes.The structure response under far-field harmonic-like earthquakes is larger than that of near-fault pulse-type earthquakes.The structure response under near-fault pulse-type earthquakes is larger than that of far-field non-harmonic earthquakes.When subjected to long-period earthquakes,the displacement of the isolated bearings exceeded the limit value,which led to instability and overturning of the structure.The structure with dampers in the isolated story could adequately control the nonlinear response of the structure,effectively reduce the displacement of the isolated bearings,and provide a convenient,efficient and economic method not only for new construction but also to retrofit existing structures.展开更多
BACKGROUND The two-way relationship between periodontitis and type 2 diabetes mellitus(T2DM)is well established.Prolonged hyperglycemia contributes to increased periodontal destruction and severe periodontitis,accentu...BACKGROUND The two-way relationship between periodontitis and type 2 diabetes mellitus(T2DM)is well established.Prolonged hyperglycemia contributes to increased periodontal destruction and severe periodontitis,accentuating diabetic complications.An inflammatory link exists between diabetic retinopathy(DR)and periodontitis,but the studies regarding this association and the role of lipoprotein(a)[Lp(a)]and interleukin-6(IL-6)in these conditions are scarce in the literature.AIM To determine the correlation of periodontal inflamed surface area(PISA)with glycated Hb(HbA1c),serum IL-6 and Lp(a)in T2DM subjects with retinopathy.METHODS This cross-sectional study comprised 40 T2DM subjects with DR and 40 T2DM subjects without DR.All subjects were assessed for periodontal parameters[bleeding on probing(BOP),probing pocket depth,clinical attachment loss(CAL),oral hygiene index-simplified,plaque index(PI)and PISA],and systemic parameters[HbA1c,fasting plasma glucose and postprandial plasma glucose,fasting lipid profile,serum IL-6 and serum Lp(a)].RESULTS The proportion of periodontitis in T2DM with and without DR was 47.5%and 27.5%respectively.Severity of periodontitis,CAL,PISA,IL-6 and Lp(a)were higher in T2DM with DR group compared to T2DM without DR group.Significant difference was observed in the mean percentage of sites with BOP between T2DM with DR(69%)and T2DM without DR(41%),but there was no significant difference in PI(P>0.05).HbA1c was positively correlated with CAL(r=0.351,P=0.001),and PISA(r=0.393,P≤0.001)in study subjects.A positive correlation was found between PISA and IL-6(r=0.651,P<0.0001);PISA and Lp(a)(r=0.59,P<0.001);CAL and IL-6(r=0.527,P<0.0001)and CAL and Lp(a)(r=0.631,P<0.001)among study subjects.CONCLUSION Despite both groups having poor glycemic control and comparable plaque scores,the periodontal parameters were higher in DR as compared to T2DM without DR.Since a bidirectional link exists between periodontitis and DM,the presence of DR may have contributed to the severity of periodontal destruction and periodontitis may have influenced the progression of DR.展开更多
In the Mediterranean region,despite bamboo being an alien species that can seriously alter plant and ani-mal biocoenosis,the area occupied by bamboo plantations continues to increase,especially for the purpose to sequ...In the Mediterranean region,despite bamboo being an alien species that can seriously alter plant and ani-mal biocoenosis,the area occupied by bamboo plantations continues to increase,especially for the purpose to seques-ter carbon(C).However,the C dynamics in the soil-plant system when bamboo is grown outside its native area are poorly understood.Here we investigated the C mitigation potential of the fast-growing Moso bamboo(Phyllostachys edulis)introduced in Italy for climate-change mitigation.We analyzed aboveground(AGB)and belowground(as root/shoot ratio)biomass,litter and soil organic C(SOC)at O-15-and 15-30-cm depths in a 4-year-old bamboo plantation in comparison with the former annual cropland on which the bamboo was established.To have an idea of the maximum C stored at an ecosystem level,a natural forest adjacent the two sites was also considered.In the plantation,C accumulation as AGB was stimulated,with 14.8±3.1 Mg C ha^(-1) stored in 3 years;because thinning was done to remove culms from the first year,the mean sequestration rate was 4.9 Mg C ha^(-1) a^(-1).The sequestration rates were high but comparable to other fast-growing tree species in Italy(e.g.,Pinus nigra).SOC was significantly higher in the bamboo plantation than in the cropland only at the 0-15 cm depth,but SOC stock did not differ.Possibly 4 years were not enough time for a clear increase in SOC,or the high nutrient uptake by bamboos might have depleted the soil nutrients,thus inhibiting the soil organic matter formation by bacteria.In comparison,the natural forest had significantly higher C levels in all the pools.For C dynamics at an ecosystem level,the bamboo plantation on the former annual cropland led to substantial C removal from the atmosphere(about 12 Mg C ha^(-1) a^(-1)).However,despite the promising C sequestration rates by bamboo,its introduction should be carefully considered due to potential ecological problems caused by this species in overexploited environments such as the Mediterranean area.展开更多
The presence of invasive plant species poses a substantial ecological impact,thus comprehensive evaluation of their potential range and risk under the influence of climate change is necessary.This study uses maximum e...The presence of invasive plant species poses a substantial ecological impact,thus comprehensive evaluation of their potential range and risk under the influence of climate change is necessary.This study uses maximum entropy(MaxEnt)modeling to forecast the likelihood of Leucaena leucocephala(Lam.)de Wit invasion in Saudi Arabia under present and future climate change scenarios.Utilizing the MaxEnt modeling,we integrated climatic and soil data to predict habitat suitability for the invasive species.We conducted a detailed analysis of the distribution patterns of the species,using climate variables and ecological factors.We focused on the important influence of temperature seasonality,temperature annual range,and precipitation seasonality.The distribution modeling used robust measures of area under the curve(AUC)and receiver-operator characteristic(ROC)curves,to map the invasion extent,which has a high level of accuracy in identifying appropriate habitats.The complex interaction that influenced the invasion of L.leucocephala was highlighted by the environmental parameters using Jackknife test.Presently,the actual geographic area where L.leucocephala was found in Saudi Arabia was considerably smaller than the theoretical maximum range,suggesting that it had the capacity to expand further.The MaxEnt model exhibited excellent prediction accuracy and produced reliable results based on the data from the ROC curve.Precipitation and temperature were the primary factors influencing the potential distribution of L.leucocephala.Currently,an estimated area of 216,342 km^(2)in Saudi Arabia was at a high probability of invasion by L.leucocephala.We investigated the potential for increased invasion hazards in the future due to climate change scenarios(Shared Socioeconomic Pathways(SSPs)245 and 585).The analysis of key climatic variables,including temperature seasonality and annual range,along with soil properties such as clay composition and nitrogen content,unveiled their substantial influence on the distribution dynamic of L.leucocephala.Our findings indicated a significant expansion of high risk zones.High-risk zones for L.leucocephala invasion in the current climate conditions had notable expansions projected under future climate scenarios,particularly evident in southern Makkah,Al Bahah,Madina,and Asir areas.The results,backed by thorough spatial studies,emphasize the need to reduce the possible ecological impacts of climate change on the spread of L.leucocephala.Moreover,the study provides valuable strategic insights for the management of invasion,highlighting the intricate relationship between climate change,habitat appropriateness,and the risks associated with invasive species.Proactive techniques are suggested to avoid and manage the spread of L.leucocephala,considering its high potential for future spread.This study enhances the overall comprehension of the dynamics of invasive species by combining modeling techniques with ecological knowledge.It also provides valuable information for decision-making to implement efficient conservation and management strategies in response to changing environmental conditions.展开更多
It is an important way to realize rural revitalization and sustainable development to guide rural settlement transition(RST)in an appropriate way.This paper uses actor network theory(ANT)to construct a theoretical fra...It is an important way to realize rural revitalization and sustainable development to guide rural settlement transition(RST)in an appropriate way.This paper uses actor network theory(ANT)to construct a theoretical framework for the study of RST.Taking two typical villages with different transition paths in rural areas of North China Plain as examples,this paper reveals the mechanism of RST and makes a comparative analysis.The results show that:1)after identifying problems and obligatory passage point,key actors recruit heterogeneous actors into the actor network by entrusting them with common interests,and realize RST under the system operation.2)Rural settlements under different transition paths have similarities in the problems to be solved,collective actions and policy factors,but there are differences in the transition process,mechanism and effect.The actor network and mechanism of RST through the path of new rural community construction are more complex and the transition effect is more thorough.In contrast,the degree of RST of retention development path is limited if there is no resource and location advantage.3)Based on the applicable conditions of different paths,this paper designs a logical framework of‘Situation-Structure-Behavior-Result’to scientifically guide the identification of RST paths under the background of rural revitalization.展开更多
This study analyzed the impact of land-based contaminants and tertiary industrial structure on economic development in the selected Bohai Bay area,China.Based on panel data spanning 2011-2020,a vector autoregressive(V...This study analyzed the impact of land-based contaminants and tertiary industrial structure on economic development in the selected Bohai Bay area,China.Based on panel data spanning 2011-2020,a vector autoregressive(VAR)model is used to analyze and forecast the short-run and long-run relationships between three industrial structures,pollutant discharge,and economic development.The results showed that the environmental index had a long-term cointegration relationship with the industrial structure economic index.Per capital chemical oxygen demand(PCOD)and per capita ammonia nitrogen(PNH_(3)N)had a positive impact on delta per capita GDP(dPGDP),while per capita solid waste(PSW),the secondary industry rate(SIR)and delta tertiary industry(dTIR)had a negative impact on dPGDP.The VAR model under this coupling system had stability and credibility.The impulse response results showed that the short-term effect of the coupling system on dPGDP was basically consistent with the Granger causality test results.In addition,variance decomposition was used in this study to predict the long-term impact of the coupling system in the next ten periods(i.e.,ten years).It was found that dTIR had a great impact on dPGDP,with a contribution rate as high as 74.35%in the tenth period,followed by the contribution rate of PCOD up to 3.94%,while the long-term contribution rates of PSW,SIR and PNH3N were all less than 1%.The results show that the government should support the development of the tertiary industry to maintain the vitality of economic development and prevent environmental deterioration.展开更多
文摘In Niger, irrigated agriculture constitutes the main alternative for meeting family needs. It is within this framework that the state and its partners have adopted strategies to promote irrigated production sites. This study was carried out on the Konni irrigated perimeter, the objective of which is to analyze the physical state of hydraulic infrastructures and their operation before the rehabilitation of the said perimeter. The methodology adopted consisted, first of all, of documentary research focused on data relating to this scope and our theme to properly guide the collection of data in the field. The field phase was then followed with an observation of hydraulic infrastructures one by one in order to assess their condition. Thus, the collected data was processed and analyzed. The results of this study show a notable deterioration of hydraulic infrastructure which affected the operating yield of the study area, with the development of barely 700 ha out of 1226 ha planned by the basic study for off-season production (57%). Bathymetric measurements showed that the volume of sediment that accumulated in the Zongo Dam is 1.2 million m3, which reduces its initial capacity from 12 million m3 to 10.8 million m3 after 43 years of service. The expansion joints of the feed canal are all in poor condition. 90% of the total length of the tertiary canals are degraded, 82.32% of the panels of the main canal C are degraded and 17.68% are cracked. All crossing structures are blocked between the RN1 and the Zongo dam. Based on this critical situation, it would be essential to consider rehabilitation work on all infrastructure in order to restore the hydraulic and even agronomic performance of the Konni irrigated area.
文摘Diuron (N-(3,4-dichlorophenyl)-N,N-dimethylurea) is one among the booster biocides substituted tributyltin as an antifouling agent. It has continued to be used ever since, though little is known about their levels in the maritime setting of Zanzibar. This paper details the occurrence and distribution of diuron around the coastline of Zanzibar Island. The reported concentrations of diuron in water ranged from Below Detection Limit to 1321.67 ± 52.3 ng/L at Bwawani. Majority of the sites showed levels above Environmental Risk Limit of 430 ng/L as proposed by the Dutch Authorities. The findings suggest the contamination is elevated especial in Harbor, Bwawani, Chapwani and even at Marine Protected Areas such Mnemba Island where the value of 620.33 ± 5.70 ng/L was recorded. The main possible sources of the contamination are cargo shipping, passenger speedboats, fishing, and tourism activities taking places in these areas. Therefore, future studies on the antifouling biocide diuron particularly on long term monitoring, chronic exposure, risk assessment, organisms’ responses and pollution models will add special value towards better understanding of the mechanisms and sustainable marine ecosystem health.
文摘Research on habitat quality in ecologically vulnerable areas has gained attention due to mountain urbanization and climate change. However, the absence of comprehensive reviews limits a systematic understanding of habitat quality. This study investigates habitat quality research in ecologically vulnerable regions of China, drawing data from Web of Science and Scopus. Using CiteSpace software analyzes trends in publication volume, geographic distribution, journal outlets, research disciplines, and keyword co-occurrence. The findings identify two distinct research phases: an initial exploratory stage and a period of steady growth, with the Loess Plateau emerging as a primary focal region. Key journals, such as Ecological Indicators and Acta Ecologica Sinica, dominate the field, reflecting contributions from disciplines including environmental science and ecology. Research hotspots center on trade-offs between habitat quality and ecosystem services, driving factors of change, landscape pattern optimization, and simulation techniques. Future research should prioritize addressing the spatial heterogeneity of vulnerable regions, advancing methodological approaches, and enhancing uncertainty analyses in model parameterization. This study provides a critical foundation for addressing key scientific challenges and guiding future research, with implications for ecological security and sustainable development.
文摘In the context of rapid urbanization,cities must leverage their unique advantages to enhance their competitiveness.It has become a prevalent practice to integrate Chinese cultural elements into a city’s brand identity,as well as to transform and elevate the existing landscape.This paper examines the landscape evolution of Nanchang Bayi Park(Baihuazhou)and the associated measures for its transformation and enhancement.The findings indicate that,from the perspective of urban visual art,these transformations significantly enhance the city’s aesthetic perception and more effectively address the needs of people.Consequently,this contributes to the ongoing improvement and development of the city’s brand image.By modifying the urban structure,enhancing the urban environment,upgrading infrastructure,and elevating the cultural levels within urban areas,the objective of transforming and upgrading urban landscapes can be realized.
基金Collaborative Project Grant from the Exploration and Development Research Institute of SINOPEC Northwest Oilfi eld Company(Grant No.KY2021-S-104).
文摘The Tarim Basin has revealed numerous tight sandstone oil and gas reservoirs.The tidal fl at zone in the Shunbei area is currently in the detailed exploration stage,requiring a comprehensive description of the sand body distribution characteristics for rational exploration well deployment.However,using a single method for sand body prediction has yielded poor results.Seismic facies analysis can eff ectively predict the macro-development characteristics of sedimentary sand bodies but lacks the resolution to capture fi ne details.In contrast,single-well sedimentary facies analysis can describe detailed sand body development but struggles to reveal broader trends.Therefore,this study proposes a method that combines seismic facies analysis with single-well sedimentary microfacies analysis,using the lower section of the Kepingtage Formation in the Shunbei area as a case study.First,seismic facies were obtained through unsupervised vector quantization to control the macro-distribution characteristics of sand bodies,while principal component analysis(PCA)was applied to improve the depiction of fi ne sand body details from seismic attributes.Based on 3D seismic data,well-logging data,and geological interpretation results,a detailed structural interpretation was performed to establish a high-precision stratigraphic framework,thereby enhancing the accuracy of sand body prediction.Seismic facies analysis was then conducted to obtain the macro-distribution characteristics of the sand bodies.Subsequently,core data and logging curves from individual wells were used to clarify the vertical development characteristics of tidal channels and sandbars.Next,PCA was employed to select the seismic attributes most sensitive to sand bodies in diff erent sedimentary facies.Results indicate that RMS amplitude in the subtidal zone and instantaneous phase in the intertidal zone are the most sensitive to sand bodies.A comparative analysis of individual seismic attributes for sand body characterization revealed that facies-based delineation improved the accuracy of sand body identifi cation,eff ectively capturing their contours and shapes.This method,which integrates seismic facies,single-well sedimentary microfacies,and machine learning techniques,enhances the precision of sand body characterization and off ers a novel approach to sand body prediction.
基金Open access funding provided by University of Natural Resources and Life Sciences Vienna(BOKU).
文摘This paper presents a standardised workflow for conducting hazard assessments of mass wasting processes in remote mountain areas with limited data.The methodology integrates geomorphological mapping and remote sensing techniques and is adaptable to different national standards,thus ensuring its applicability in a variety of contexts.The principal objective is to guarantee the safety of mountainous regions,particularly in the vicinity of essential infrastructure,where the scope for implementing structural measures is restricted.The framework commences with comprehensive geomorphological mapping,which facilitates the identification of past hazardous processes and potential future hazards.New technologies,such as uncrewed aerial vehicles(UAVs),are employed to create high-resolution DEMs,which are particularly beneficial in regions with limited data availability.These models facilitate the assessment of potential hazards and inform decisions regarding protective measures.The utilisation of UAVs enhances the accuracy and efficiency of data collection,particularly in remote mountainous regions where alternative remotely sensed information may be unavailable.The integration of modern approaches into traditional hazard assessment methods allows for a comprehensive analysis of the spatial distribution of factors driving mass wasting processes.This workflow provides valuable insights that assist in the prioritisation of interventions and the optimisation of risk reduction in high mountainous areas.
基金The financial support by the Deutsche Bundesstiftung Umwelt (DBU)
文摘Deforestation remains one of the most imminent threats to biodiversity in the tropics.As such,its causes and dynamics need to be studied and understood to put a halt to further forest loss and degradation.In tropical countries such as Uganda,agricultural expansion and wood fuel demand are its leading drivers.While the establishment of protected areas is a key tool in conserving remaining forest biodiversity,results indicate that current management does not sufficiently provide alternatives to forest resources utilised by households and income provided from timber and non-timber forest products.Beyond safeguarding ecosystems,protected areas need to ensure the sustainable socioeconomic development of adjacent communities for effective biodiversity conservation–however,both management and research often neglect to consider all dimensions.In this study,we analysed five decades of forest cover change in the Mount Elgon region,Uganda,by conducting a remote sensing analysis of its protected areas using Landsat MSS and TM data from 1973-2023 in combination with literature and subsequent interview analysis to consider both the ecological and socioeconomic dimension.We applied a random forest approach to differentiate forest and non-forest areas and carried out a pixel-based change detection analysis to differentiate temporal and spatial changes.Throughout the study period of 50 years,forest cover has evolved dynamically within the boundaries of the protected areas of Mount Elgon.A significant decline was observed in both Mount Elgon National Park with a loss of-5.98%(-46.83km²)and Mount Elgon Biosphere Reserve with a loss of-14.96%(-134.33km²).Our results showcase a cycle of deforestation and afforestation that could be tied to a series of development initiatives,re-demarcation of boundaries,changes in management and recurring evictions.Overall,the results lead to the conclusion that the lack of sustainable and efficient management and funding has fostered the rate of deforestation and accelerated ecological degradation in the region,but that existing problems are also rooted in the land tenure history of the region.We recommend the proper implementation of participatory and long-term management approaches on the ground and to address the land rights issue to contribute to both socioeconomic wellbeing and sustainable conservation outcomes.
基金Supported by the Special Study on Mineral Resources Planning in Changchun City(No.JM-2020-11-13594)Jilin Agricultural Geological Survey Project(No.12120105111208)。
文摘In order to identify the nutrient level and environmental quality of paddy fields in Wanchang area,and to provide scientific basis and technical support for planting rice in Wanchang area, the soil geochemicalsurvey was carried out, 30 samples were collected from paddy soil in Wanchang area, and 20 elements(indicators) were analyzed. The characterization of the elemental content of soils in the study area was carriedout, and the geochemical level for soil nutrients, the geochemical level for the soil environment, and thecomprehensive geochemical level of soil quality were evaluated. The results showed that the average valuesof K content and pH of the soil in the study area were smaller than the background values of Jilin Province,and the average values of 18 elements including N, P, Ca, S, Pb, Zn etc. were bigger than the backgroundvalues of Jilin Province. The results of the evaluation of soil single element nutrient in the study area showedthat the available state nutrient levels of Mn, Zn, Cu, and K increased compared with the total amounts ofnutrients level, with Cu increasing the most;the available state nutrient level of N, P, B, and Mo decreasedcompared with the total amounts of nutrients level, with Mo decreasing the most. The comprehensive levelof soil nutrients geochemistry in paddy fields was mainly Level III (medium), accounting for 53.33%, andthe low abundance level was caused by the lack of P element;the comprehensive level of soil environmentalgeochemistry was mainly Level I (clean), accounting for 96.67%, with only slight pollution caused byCd. The comprehensive geochemical level of soil quality was mainly Level II, accounting for 66.67%.Suggestions were put forward for the rational utilization of soil resources in paddy fields in the study area.
基金Supported by National Natural Science Foundation of China(No.82160195,No.82460203)Science and Technology Project of Jiangxi Provincial Department of Education(No.GJJ200169)+1 种基金Science and Technology Project of Jiangxi Province Health Commission of Traditional Chinese Medicine(No.2020A0087)Science and Technology Project of Jiangxi Health Commission(No.202130210).
文摘AIM:To elucidate the neuropathological mechanisms underlying diabetic vitreous hemorrhage(DVH)and its correlation with clinical characteristics.METHODS:Twenty-one individuals with DVH(male/female 12/9;mean age 52.29±11.66y)were selected,alongside 21 appropriately matched controls with diabetes mellitus(DM).Voxel-based morphometry(VBM)techniques were employed to identify aberrant functional regions in the brain.Receiver operating characteristic(ROC)curves were utilized for classification based on the average VBM values of the two groups,and Pearson correlation analysis was conducted to assess the relationship between average VBM values in distinct brain regions and clinical manifestations.RESULTS:Relative to the DM controls,DVH patients exhibited reduced VBM values in the right superior temporal pole,the right superior temporal gyrus,the right medial orbital frontal gyrus,and the left superior frontal gyrus.Furthermore,ROC curve analysis of these four brain regions in DVH patients demonstrated a high degree of accuracy,as indicated by the area under the curve.The average VBM value in each of these regions exhibited a negative correlation with both the duration of DVH and the score on the Hospital Anxiety and Depression Scale(HADS).CONCLUSION:Pathological alterations in four distinct brain regions are observed in patients with DVH,potentially reflecting neuropathological changes associated with this condition.
基金supported by the National Natural Science Foundation of China(Grant Nos.42371315,41901213)the Humanities and Social Sciences General Research Program of the Ministry of Education(Grant No.23YJC790141)。
文摘Cropland abandonment has been a widespread phenomenon in mountainous areas due to the increasing number of natural disasters and the massive migration of rural labor in the process of rapid urbanization.Land transfer is a crucial prerequisite for ensuring food security and fostering rural revitalization.How to promote land transfer in mountainous areas remains a challenging but important task.Nevertheless,there is a dearth of research examining land transfers among farm households that specifically address mountainous regions,and the influence of grassroots governance and geographic location has not been thoroughly elucidated within this particular context.Based on 895household samples collected in Dabie Mountainous Area in China,this study employs binary and ordinal logistic regression models to provide a more comprehensive analysis on land transfers among rural households and the determinants,including the decision to transfer land,the existence of land transfer rents,the channel of land transfer,the duration of the transfer,the pre-transfer cultivation situation,and the level of satisfaction with the land transfer rent.The findings reveal that grassroots governance,geographic location,livelihood capital,and demographic factors significantly influence land transfers among rural households.Specifically,villagers'public participation positively affects land transfer participation(β=0.235,p<0.05),while the operation of village rules and regulations negatively impacts it(β=-0.296,p<0.05).Village cadre satisfaction positively influences both land transfer rent(β=0.274,p<0.05)and rent satisfaction(β=0.303,p<0.05).Improved civil relations in the village correlate with lower land transfer rent(β=-0.511,p<0.05),while a better social atmosphere is associated with higher satisfaction with transfer rent(β=0.575,p<0.01).Households at higher elevations tend to prefer government-mediated land transfers with longer durations.The distances to the township and county centers have contrasting effects on land transfer rent,but their impacts on participation in land transfer,choice of transfer channel,and duration are consistent.The study also found that different types of livelihood capital,as well as the demographic characteristics of households,significantly affect various aspects of land transfer.These empirical findings can inform policymaking to promote more efficient land transfers in mountainous region.
文摘We build a computer program to reconstruct convex bodies using even L_(p)surface area measures for p≥1.Firstly,we transform the minimization problem Pi,which is equivalent to solving the even L_(p)Minkowski problem,into a convex optimization problem P4 with a finite number of constraints.This transformation makes it suitable for computational resolution.Then,we prove that the approximate solutions obtained by solving the problem P4 converge to the theoretical solution when N and k are sufficiently large.Finally,based on the convex optimization problem P_(4),we provide an algorithm for reconstructing convex bodies from even L_(p)surface area measures,and present several examples implemented using MATLAB.
基金National Natural Science Foundation of China(62373187)Forward-looking Layout Special Projects(ILA220591A22)。
文摘In the field of calculating the attack area of air-to-air missiles in modern air combat scenarios,the limitations of existing research,including real-time calculation,accuracy efficiency trade-off,and the absence of the three-dimensional attack area model,restrict their practical applications.To address these issues,an improved backtracking algorithm is proposed to improve calculation efficiency.A significant reduction in solution time and maintenance of accuracy in the three-dimensional attack area are achieved by using the proposed algorithm.Furthermore,the age-layered population structure genetic programming(ALPS-GP)algorithm is introduced to determine an analytical polynomial model of the three-dimensional attack area,considering real-time requirements.The accuracy of the polynomial model is enhanced through the coefficient correction using an improved gradient descent algorithm.The study reveals a remarkable combination of high accuracy and efficient real-time computation,with a mean error of 91.89 m using the analytical polynomial model of the three-dimensional attack area solved in just 10^(-4)s,thus meeting the requirements of real-time combat scenarios.
基金Under the auspices of National Natural Science Foundation of China(No.42371315,41901213)Natural Science Foundation of Hubei Province(No.2020CFB856)Project of Changjiang Survey,Planning,Design and Research Co.,Ltd(No.CX2022Z23)。
文摘Investigating the ecological impact of land use change in the context of the construction of national water network project is crucial,as it is imperative for achieving the sustainable development goals of the national water network and guaranteeing regional ecological stability.Using the Danjiangkou Reservoir Area(DRA),China as the study area,this paper first examined the spatiotemporal dynamics of natural landscape patterns and ecosystem service values(ESV)in the DRA from 2000 to 2018 and then investigated the spatial clustering characteristics of the ESV using spatial statistical analysis tools.Finally,the patch-generating land use simulation(PLUS)model was used to simulate the natural landscape and future changes in the ESV of the DRA from 2018 to 2028 under four different development scenarios:business as usual(BAU),economic development(ED),ecological protection(EP),and shoreline protection(SP).The results show that:during 2000-2018,the construction of water facilities had a significant impact on regional land use/land cover(LULC)change,with a 24830 ha increase in watershed area.ESV exhibited an increasing trend,with a significant and growing spatial clustering effect.The transformation of farmland to water bodies led to accelerated ESV growth,while the transformation of forest land to farmland led to a decrease in the ESV.Normalized difference vegetation index(NDVI)had the strongest effect on the ESV.ESV exhibited a continuous increase from 2018 to 2028 under all the simulation scenarios.The EP scenario had the greatest increase in ESV,while the ED scenario had the smallest increase.The findings suggest that projected land use patterns under different scenarios have varied impacts on ecosystem services(ESs)and that the management and planning of the DRA should balance social,economic,ecological,and security benefits.nomic,ecological,and security benefits.
基金supported by the National Key Research and Development Program of China(2021YFC2902004)the National Natural Science Foundation of China(42072284,42027801,and 41877186).
文摘A substantial reduction in groundwater level,exacerbated by coal mining activities,is intensifying water scarcity in western China’s ecologically fragile coal mining areas.China’s national strategic goal of achieving a carbon peak and carbon neutrality has made eco-friendly mining that prioritizes the protection and efficient use of water resources essential.Based on the resource characteristics of mine water and heat hazards,an intensive coal-water-thermal collaborative co-mining paradigm for the duration of the mining process is proposed.An integrated system for the production,supply,and storage of mining companion resources is achieved through technologies such as roof water inrush prevention and control,hydrothermal quality improvement,and deep-injection geological storage.An active preventive and control system achieved by adjusting the mining technology and a passive system centered on multiobjective drainage and grouting treatment are suggested,in accordance with the original geological characteristics and dynamic process of water inrush.By implementing advanced multi-objective drainage,specifically designed to address the“skylight-type”water inrush mode in the Yulin mining area of Shaanxi Province,a substantial reduction of 50%in water drillings and inflow was achieved,leading to stabilized water conditions that effectively ensure subsequent safe coal mining.An integrated-energy complementary model that incorporates the clean production concept of heat utilization is also proposed.The findings indicate a potential saving of 8419 t of standard coal by using water and air heat as an alternative heating source for the Xiaojihan coalmine,resulting in an impressive energy conservation of 50.2%and a notable 24.2%reduction in carbon emissions.The ultra-deep sustained water injection of 100 m^(3)·h^(-1)in a single well would not rupture the formation or cause water leakage,and 7.87×10^(5)t of mine water could be effectively stored in the Liujiagou Formation,presenting a viable method for mine-water management in the Ordos Basin and providing insights for green and low-carbon mining.
基金National Natural Science Fund of China under Nos.52168072 and 51808467High-level Talents Support Plan of Yunnan Province of China(2020)。
文摘At present,there is not much research on mid-story isolated structures in mountainous areas.In this study,a model of a mid-story isolated structure considering soil-structure interaction(SSI)in mountainous areas is established along with a model that does not consider SSI.Eight long-period earthquake waves and two ordinary earthquake waves are selected as inputs for the dynamic time history analysis of the structure.The results show that the seismic response of a mid-story isolated structure considering SSI in mountainous areas can be amplified when compared with a structure that does not consider SSI.The structure response under long-period earthquakes is larger than that of ordinary earthquakes.The structure response under far-field harmonic-like earthquakes is larger than that of near-fault pulse-type earthquakes.The structure response under near-fault pulse-type earthquakes is larger than that of far-field non-harmonic earthquakes.When subjected to long-period earthquakes,the displacement of the isolated bearings exceeded the limit value,which led to instability and overturning of the structure.The structure with dampers in the isolated story could adequately control the nonlinear response of the structure,effectively reduce the displacement of the isolated bearings,and provide a convenient,efficient and economic method not only for new construction but also to retrofit existing structures.
文摘BACKGROUND The two-way relationship between periodontitis and type 2 diabetes mellitus(T2DM)is well established.Prolonged hyperglycemia contributes to increased periodontal destruction and severe periodontitis,accentuating diabetic complications.An inflammatory link exists between diabetic retinopathy(DR)and periodontitis,but the studies regarding this association and the role of lipoprotein(a)[Lp(a)]and interleukin-6(IL-6)in these conditions are scarce in the literature.AIM To determine the correlation of periodontal inflamed surface area(PISA)with glycated Hb(HbA1c),serum IL-6 and Lp(a)in T2DM subjects with retinopathy.METHODS This cross-sectional study comprised 40 T2DM subjects with DR and 40 T2DM subjects without DR.All subjects were assessed for periodontal parameters[bleeding on probing(BOP),probing pocket depth,clinical attachment loss(CAL),oral hygiene index-simplified,plaque index(PI)and PISA],and systemic parameters[HbA1c,fasting plasma glucose and postprandial plasma glucose,fasting lipid profile,serum IL-6 and serum Lp(a)].RESULTS The proportion of periodontitis in T2DM with and without DR was 47.5%and 27.5%respectively.Severity of periodontitis,CAL,PISA,IL-6 and Lp(a)were higher in T2DM with DR group compared to T2DM without DR group.Significant difference was observed in the mean percentage of sites with BOP between T2DM with DR(69%)and T2DM without DR(41%),but there was no significant difference in PI(P>0.05).HbA1c was positively correlated with CAL(r=0.351,P=0.001),and PISA(r=0.393,P≤0.001)in study subjects.A positive correlation was found between PISA and IL-6(r=0.651,P<0.0001);PISA and Lp(a)(r=0.59,P<0.001);CAL and IL-6(r=0.527,P<0.0001)and CAL and Lp(a)(r=0.631,P<0.001)among study subjects.CONCLUSION Despite both groups having poor glycemic control and comparable plaque scores,the periodontal parameters were higher in DR as compared to T2DM without DR.Since a bidirectional link exists between periodontitis and DM,the presence of DR may have contributed to the severity of periodontal destruction and periodontitis may have influenced the progression of DR.
基金supported by the “Project funded by the European Union-Next Generation EU”
文摘In the Mediterranean region,despite bamboo being an alien species that can seriously alter plant and ani-mal biocoenosis,the area occupied by bamboo plantations continues to increase,especially for the purpose to seques-ter carbon(C).However,the C dynamics in the soil-plant system when bamboo is grown outside its native area are poorly understood.Here we investigated the C mitigation potential of the fast-growing Moso bamboo(Phyllostachys edulis)introduced in Italy for climate-change mitigation.We analyzed aboveground(AGB)and belowground(as root/shoot ratio)biomass,litter and soil organic C(SOC)at O-15-and 15-30-cm depths in a 4-year-old bamboo plantation in comparison with the former annual cropland on which the bamboo was established.To have an idea of the maximum C stored at an ecosystem level,a natural forest adjacent the two sites was also considered.In the plantation,C accumulation as AGB was stimulated,with 14.8±3.1 Mg C ha^(-1) stored in 3 years;because thinning was done to remove culms from the first year,the mean sequestration rate was 4.9 Mg C ha^(-1) a^(-1).The sequestration rates were high but comparable to other fast-growing tree species in Italy(e.g.,Pinus nigra).SOC was significantly higher in the bamboo plantation than in the cropland only at the 0-15 cm depth,but SOC stock did not differ.Possibly 4 years were not enough time for a clear increase in SOC,or the high nutrient uptake by bamboos might have depleted the soil nutrients,thus inhibiting the soil organic matter formation by bacteria.In comparison,the natural forest had significantly higher C levels in all the pools.For C dynamics at an ecosystem level,the bamboo plantation on the former annual cropland led to substantial C removal from the atmosphere(about 12 Mg C ha^(-1) a^(-1)).However,despite the promising C sequestration rates by bamboo,its introduction should be carefully considered due to potential ecological problems caused by this species in overexploited environments such as the Mediterranean area.
基金the Researchers Supporting Project(RSP2024R347),King Saud University,Riyadh,Saudi Arabia.
文摘The presence of invasive plant species poses a substantial ecological impact,thus comprehensive evaluation of their potential range and risk under the influence of climate change is necessary.This study uses maximum entropy(MaxEnt)modeling to forecast the likelihood of Leucaena leucocephala(Lam.)de Wit invasion in Saudi Arabia under present and future climate change scenarios.Utilizing the MaxEnt modeling,we integrated climatic and soil data to predict habitat suitability for the invasive species.We conducted a detailed analysis of the distribution patterns of the species,using climate variables and ecological factors.We focused on the important influence of temperature seasonality,temperature annual range,and precipitation seasonality.The distribution modeling used robust measures of area under the curve(AUC)and receiver-operator characteristic(ROC)curves,to map the invasion extent,which has a high level of accuracy in identifying appropriate habitats.The complex interaction that influenced the invasion of L.leucocephala was highlighted by the environmental parameters using Jackknife test.Presently,the actual geographic area where L.leucocephala was found in Saudi Arabia was considerably smaller than the theoretical maximum range,suggesting that it had the capacity to expand further.The MaxEnt model exhibited excellent prediction accuracy and produced reliable results based on the data from the ROC curve.Precipitation and temperature were the primary factors influencing the potential distribution of L.leucocephala.Currently,an estimated area of 216,342 km^(2)in Saudi Arabia was at a high probability of invasion by L.leucocephala.We investigated the potential for increased invasion hazards in the future due to climate change scenarios(Shared Socioeconomic Pathways(SSPs)245 and 585).The analysis of key climatic variables,including temperature seasonality and annual range,along with soil properties such as clay composition and nitrogen content,unveiled their substantial influence on the distribution dynamic of L.leucocephala.Our findings indicated a significant expansion of high risk zones.High-risk zones for L.leucocephala invasion in the current climate conditions had notable expansions projected under future climate scenarios,particularly evident in southern Makkah,Al Bahah,Madina,and Asir areas.The results,backed by thorough spatial studies,emphasize the need to reduce the possible ecological impacts of climate change on the spread of L.leucocephala.Moreover,the study provides valuable strategic insights for the management of invasion,highlighting the intricate relationship between climate change,habitat appropriateness,and the risks associated with invasive species.Proactive techniques are suggested to avoid and manage the spread of L.leucocephala,considering its high potential for future spread.This study enhances the overall comprehension of the dynamics of invasive species by combining modeling techniques with ecological knowledge.It also provides valuable information for decision-making to implement efficient conservation and management strategies in response to changing environmental conditions.
基金Under the auspices of the Taishan Scholars Project Special FundsNational Natural Science Fundation of China(No.42077434,42001199)Youth Innovation Technology Project of Higher School in Shandong Province(No.2019RWG016)。
文摘It is an important way to realize rural revitalization and sustainable development to guide rural settlement transition(RST)in an appropriate way.This paper uses actor network theory(ANT)to construct a theoretical framework for the study of RST.Taking two typical villages with different transition paths in rural areas of North China Plain as examples,this paper reveals the mechanism of RST and makes a comparative analysis.The results show that:1)after identifying problems and obligatory passage point,key actors recruit heterogeneous actors into the actor network by entrusting them with common interests,and realize RST under the system operation.2)Rural settlements under different transition paths have similarities in the problems to be solved,collective actions and policy factors,but there are differences in the transition process,mechanism and effect.The actor network and mechanism of RST through the path of new rural community construction are more complex and the transition effect is more thorough.In contrast,the degree of RST of retention development path is limited if there is no resource and location advantage.3)Based on the applicable conditions of different paths,this paper designs a logical framework of‘Situation-Structure-Behavior-Result’to scientifically guide the identification of RST paths under the background of rural revitalization.
基金supported by the research funds for Coupling Research on Industrial Upgrade and Environmental Management in the Bohai Rim-Technique,methodology,and Environmental Economic Policies(No.42076221).
文摘This study analyzed the impact of land-based contaminants and tertiary industrial structure on economic development in the selected Bohai Bay area,China.Based on panel data spanning 2011-2020,a vector autoregressive(VAR)model is used to analyze and forecast the short-run and long-run relationships between three industrial structures,pollutant discharge,and economic development.The results showed that the environmental index had a long-term cointegration relationship with the industrial structure economic index.Per capital chemical oxygen demand(PCOD)and per capita ammonia nitrogen(PNH_(3)N)had a positive impact on delta per capita GDP(dPGDP),while per capita solid waste(PSW),the secondary industry rate(SIR)and delta tertiary industry(dTIR)had a negative impact on dPGDP.The VAR model under this coupling system had stability and credibility.The impulse response results showed that the short-term effect of the coupling system on dPGDP was basically consistent with the Granger causality test results.In addition,variance decomposition was used in this study to predict the long-term impact of the coupling system in the next ten periods(i.e.,ten years).It was found that dTIR had a great impact on dPGDP,with a contribution rate as high as 74.35%in the tenth period,followed by the contribution rate of PCOD up to 3.94%,while the long-term contribution rates of PSW,SIR and PNH3N were all less than 1%.The results show that the government should support the development of the tertiary industry to maintain the vitality of economic development and prevent environmental deterioration.
