Cold tolerance is one of the important traits for grapevine,especially in regions with extremely low temperatures in winter.Vitis amurensis is wild species in the Vitis genus with excellent cold hardiness compared wit...Cold tolerance is one of the important traits for grapevine,especially in regions with extremely low temperatures in winter.Vitis amurensis is wild species in the Vitis genus with excellent cold hardiness compared with Vitis vinifera.However,metabolites that contribute to the cold tolerance of V.amurensis remain unknown.Here,the metabolomics of buds from V.amurensis‘Zuoshan-1'during cold acclimation(CA)were identified,and cold-sensitive cultivar(V.vinifera‘Jingzaojing')was used as the control.The buds were collected in October,November,and December in 2016 and 2018.The cold hardiness of the buds increased during CA in the two grapevines.However,browning was observed only in V.vinifera buds at temperature below-10℃.Among detected metabolites from buds,443 metabolites were overlapped between two years.Forty-four and thirty differentially accumulated metabolites(DAMs)were identified in V.amurensis and V.vinifera,respectively.Ten DAMs including monoacylglycerol(MAG,18:2)isomer 1,trehalose 6-phosphate,and D-glucose showed identical variations in the two grapevines,indicating conserved CA responses within the Vitis genus.Eighteen DAMs exhibited higher accumulation in V.amurensis than in V.vinifera.Maltotetraose,D-glucoronic acid,L-aspartic acid,azelaic acid,and 4-hydroxybenzoic acid were reported to accumulate during CA in other plants.Enhanced cold tolerance was detected in grapevine leaves with exogenous 5 mmol L^(-1)L-aspartic acid and 1%proanthocyanidins.Potential contributions of other DAMs found in V.amurensis such as Cyanidin 3-O-glucoside need to be further elucidated.Thus,eighteen metabolites accumulated in V.amurensis can be used for practical application in improvement of cold resistance in grapevine.Our findings provide new insights into understanding the cold hardiness of V.amurensis.展开更多
Bistate plates have found extensive applications in the domains of smart structures and energy harvesting devices.Most bistable curved plates are characterized by a constant thickness profile.Regrettably,due to the in...Bistate plates have found extensive applications in the domains of smart structures and energy harvesting devices.Most bistable curved plates are characterized by a constant thickness profile.Regrettably,due to the inherent complexity of this problem,relatively little attention has been devoted to this area.In this study,we demonstrate how deep learning can facilitate the discovery of novel plate profiles that cater to multiple objectives,including maximizing stiffness,forward snapping force,and backward snapping force.Our proposed approach is distinguished by its efficiency in terms of low computational energy consumption and high effectiveness.It holds promise for future applications in the design and optimization of multistable structures with diverse objectives,addressing the requirements of various fields.展开更多
The labyrinth seal in turbomachinery is a key element that restricts leakage flow among rotor-stator clearances from high-pressure regions to low-pressure regions. The fluid-induced forces on the rotor from seals duri...The labyrinth seal in turbomachinery is a key element that restricts leakage flow among rotor-stator clearances from high-pressure regions to low-pressure regions. The fluid-induced forces on the rotor from seals during machine operation must be accurately quantified to predict their dynamic behavior effectively. To understand the fluid-induced force characteristics of the labyrinth seal more fully, the effects of four types of pre-swirls on the leakage, flow field, and fluid-induced force of a rotary straight-through labyrinth gas seal (RSTLGS) were numerically investigated using the proposed steady computational fluid dynamics (CFD) method based on the three-dimensional models of the RSTLGS. The leakage, flow field, and fluid-induced force of the RSTLGS for six axial pre-swirl velocities, four radial preswirl angles, four circumferential positive pre-swirl angles, and four circumferential negative pre-swirl angles were computed under the same geometrical parameters and operational conditions. Mesh analysis ensures the accuracy of the present steady CFD method. The numerical results show that the four types of pre-swirls influence the leakage, flow field, and fluid-induced force of the RSTLGS. The axial pre-swirl velocity remarkably inhibits the fluid-induced force, and the circumferential positive pre-swirl angle and circumferential negative pre-swirl angle remarkably promote the fluid-induced force. The effects of the radial pre-swirl angle on the fluid-induced force are complicated, and the pressure forces and viscous forces show the maximum or minimum values at a specific radial pre-swirl angle. The pre-swirl has a negligible impact on the leakage. The four types of pre-swirls affect the leakage, flow field, and fluidinduced force of the RSTLGS to varying degrees. The pre-swirl is the influence factor affecting the leakage, flow field, and fluid-induced force of the RSTLGS. The conclusions will help to understand the fluid-induced force of labyrinth seals more fully, by providing helpful suggestions for engineering practices and a theoretical basis to analyze the fluid–structure interaction of the seal-rotor system in future research.展开更多
Investigation on spatiotemporal variations of maximum seasonal freeze depth （MSFD） over the Heihe River Basin is of great importance for systematic understanding of regional climate and environmental change, ecologi...Investigation on spatiotemporal variations of maximum seasonal freeze depth （MSFD） over the Heihe River Basin is of great importance for systematic understanding of regional climate and environmental change, ecological-hydrological processes, water resources assessment, construction and resource development. Based on soil and air temperatures at the meteorological stations of the China Meteorological Administration （CMA） over the Heihe River Basin, MSFDs time series are structured into a composite time series over the 1960-2007 period. Evaluating the averaged MSFD time series for 1960 2007 reveals a statistically significant trend of 4.0 cm/decade or a net change of-19.2 cm for the 48-year period over the basin. The MSFD had significantly negative correlation with mean annual air temperature （MAAT）, winter air temperature, mean annual ground surface temperature （MAGST）, degree days of thawing for the air （DDTa） as well as for the surface （DDTs）, and degree days of freezing for the surface （DDFs）. While there was significantly positive correlation between DDF,. and MSFD time series, MSFD was deeper and changed greatly in the Heihe River source area. It was shallower in the east-central basin and gradually deepened in other sections of the basin. The MSFD distribution pattern in 2003-2005 is consistent with that of averaged degree days of freezing for air （DDFa） in 1960-2007. However, the maximum of MSFD may not be accurate, because there is no long term observation data in the deep seasonally frozen ground regions near the lower boundary of permafrost. With increasing elevation, averaged DDFa increased at a rate of 51.6 ℃-day/100m, therefore, the MSFG and the date reaching MSFG became deeper and later, respectively.展开更多
Histone H3 lysine 27 trimethylation(H3K27me3) is a histone modification associated with transcriptional repression. However, insights into the genome-wide pattern of H3K27me3 in grapevines are limited. Here, anti-H3K2...Histone H3 lysine 27 trimethylation(H3K27me3) is a histone modification associated with transcriptional repression. However, insights into the genome-wide pattern of H3K27me3 in grapevines are limited. Here, anti-H3K27 chromatin immunoprecipitation(ChIP), high-throughput sequencing, and transcriptome analysis were performed using leaves of Vitis amurensis. The leaves were treated at 4°C for 2 h and 24 h and used to investigate changes in H3K27me3 under chilling treatment. The results show that H3K27me3 is well-distributed both in gene regions(-50%) and in the intergenic region(-50%) in the grapevine genome(Vitis vinifera ‘Pinot Noir PN40024'). H3K27me3 was found to be localized in8 368 annotated gene regions in all detected samples(leaves at normal temperature and under chilling treatments) and mainly enriched in gene bodies with the adjacent promoter and downstream areas. The short-term chilling treatments(4°C for 2 h) induced 2 793 gains and 305losses in H3K27me3 modification. Subsequently, 97.3% of the alterations were restored to original levels after 24 h treatment. The ChIP-qPCR for five differential peaks showed similar results to the data for ChIP-seq, indicating that the chilling-induced H3K27me3 modification is reliable.Integrative analysis of transcriptome and ChIP-seq results showed that the expression of H3K27me3 target genes was significantly lower than those of non-target genes, indicating transcriptional repression of H3K27me3 in grapevine leaves. Furthermore, histone methylation alterations were detected in 82 genes and were related to either repression or activation of their expression during chilling stress. The findings provide the genome-wide H3K27me3 patterns in grapevines and shed light on uncovering its regulation in chilling stress responses.展开更多
Changes in ground surface thermal regimes play a vital role in surface and subsurface hydrology, ecosystem diversity and productivity, and global thermal, water and carbon budgets as well as climate change. Estimating...Changes in ground surface thermal regimes play a vital role in surface and subsurface hydrology, ecosystem diversity and productivity, and global thermal, water and carbon budgets as well as climate change. Estimating spring, summer, autumn and winter air temperatures and mean annual air temperature（MAAT） from 1960 through 2008 over the Heihe River Basin reveals a statistically significant trend of 0.31 °C/decade, 0.28 °C/decade, 0.37 °C/decade, 0.50 °C/decade, and 0.37 °C /decade, respectively. The averaged time series of mean annual ground surface temperature（MAGST） and maximum annual ground surface temperature（MaxAGST） for 1972–2006 over the basin indicates a statistically significant trend of 0.58 °C/decade and 1.27 °C/decade, respectively. The minimum annual ground surface temperature（MinAGST） in the same period remains unchanged as a whole. Estimating surface freezing/thawing index as well as the ratio of freezing index to thawing index（RFT） in the period between 1959 and 2006 over the basin indicates a statistically significant trend of-42.5 °C-day/decade, 85.4 °C-day/decade and-0.018/decade, respectively.展开更多
As a key supporting equipment for the construction of LNG carriers,the installation platform undertakes the support and guarantee of LNG carrier tank internal construction.This paper takes the secondary shielding inst...As a key supporting equipment for the construction of LNG carriers,the installation platform undertakes the support and guarantee of LNG carrier tank internal construction.This paper takes the secondary shielding installation platform of A-type tank as the object of study,the study firstly considers the semi-rigidity of the nodes and the material nonlinearity based on finite element software,and then the residual structure is calculated using static nonlinear method after single truss,two trusses and three trusses are invalid simultaneously.The research results show that the truss with higher components importance coefficient has greater impact on the residual structure when the truss is invalid;After the 2 trusses of installation platform become invalid completely,the further progressive collapse will not occur;When A1-HJ,A2-HJ and A2-HJ are dismantled at the same time,it will lead to the local progressive damage,which can cause the collapse of large-scale structures.The research findings can support the design and use of the installation platform.展开更多
As indispensable strategic materials for high-tech industries,rare earth elements and yttrium(REY)have become particularly important in recent years,raising the demand of developing new approaches for reclamation of R...As indispensable strategic materials for high-tech industries,rare earth elements and yttrium(REY)have become particularly important in recent years,raising the demand of developing new approaches for reclamation of REY from REY-rich materials such as coal combustion products(CCPs).In this study,five coal-fired power plants(CFPPs)in Guizhou of southwest China were selected for investigating REY concentrations of solid samples,atmospheric emissions,and recovery potentials.REY concentrations of feed fuels are higher in this study(147.2-468.6 mg/kg)than what have been reported previously for coals in China and the world.REY atmospheric emissions are extremely low(38.70-180.11 mg REY/t coal).REY are enriched in bottom ash and fly ash,with average of 658±296 mg/kg and maximum of 1257 mg/kg from the five CFPPs.Relative enrichment factors(REF)of REY in bottom ash and fly ash compared with the feed fuel are 0.86-1.02 and 0.91-1.04,respectively.REY concentrations in desulfurized gypsum are very low(6-17 mg/kg),and that is mostly inherited from limestone.Critical REY(Nd,Eu,Tb,Dy,Y,and Er)in bottom/fly ash account for 34%-39%of the total REY and the outlook coefficients(Cout1)are in the range of 0.89-1.11.This study indicates a promising prospect to reclaim REY from REYrich CCPs(bottom and fly ash)in CFPPs in Guizhou,especially in the central-north Guizhou,although such practices require further technology advancement.展开更多
Aims The aim of this paper is to assess morphological and leaf stoichiometric responses of Dendrosenecio keniensis and Lobelia gregoriana to extreme environmental conditions along an elevation gradient in tropical mou...Aims The aim of this paper is to assess morphological and leaf stoichiometric responses of Dendrosenecio keniensis and Lobelia gregoriana to extreme environmental conditions along an elevation gradient in tropical mountains.Methods In this study,we assessed the variation of the morphological traits,including plant height,leaf area,leaf thickness,leaf dry weight,specific leaf area and the leaf stoichiometry traits nitrogen,carbon and phosphorous of the two endemic species D.keniensis and L.gregoriana.We further explored the relations of these morphological traits to soil organic carbon,soil total nitrogen,soil phosphorous,annual mean temperature,annual mean precipitation,annual total solar radiation,water vapor pressure and the topographic variables aspect,slope and hill shade along the elevation gradient.Ninety 10 m×10 m sampling plots were set up along the elevation gradient ranging from 3500 to 4300 m.We used 1 km×1 km grid cells to rasterize our study area in ArcGIS 10.5 for easy access to data pertaining to the climate of each elevation band.We performed linear regression of the morphological and leaf stoichiometric traits with elevation as explanatory variable.We conducted correlation analysis on the morphological and leaf stoichiometric traits with climatic,soil and topographic variables along the elevation gradient.Important Findings Dendrosenecio keniensis had wool-like pubescent leaves while L.gregoriana had mucilage packed succulent and waxy cuticle leaves to avoid freezing.Both species exhibited reduced metabolic rates as shown by the low leaf phosphorous content.Our results also showed that changes in morphology and leaf stoichiometry were determined by a combination of climate,soil and topographic variables that change along elevation on Mount Kenya.The observed variations in the morphological and leaf stoichiometric traits of D.keniensis and L.gregoriana,which grow side by side along the elevation gradient,were interpreted as adaptation to the harsh environmental conditions.展开更多
The coupling effects and mechanisms of water,heat,and salt in frozen soils are considered to be one of the core scientific issues in frozen soil studies.This study was based on in situ observation data of active layer...The coupling effects and mechanisms of water,heat,and salt in frozen soils are considered to be one of the core scientific issues in frozen soil studies.This study was based on in situ observation data of active layer soil volumetric water content(VWC),temperature,and bulk electrical conductivity(EC)obtained at an alpine meadow site from October 2016 to November 2019.The site is located in the headwater area of the Yellow River(HAYR).We analyzed the synergetic variations of active layer soil VWC,temperature,and bulk EC during the freeze and thaw processes and discussed the underlying mechanisms.When the thaw process occurred from 10 to 80 cm depths,the VWC and bulk EC at a 10 cm depth showed syn-chronous high-frequency fluctuations and both increased linearly.The linear decreasing rate of the VWC(bulk EC)at an 80 cm depth in the freeze depths between 0 and 40 cm was 2(1.6e2.3)times that of the VWC(bulk EC)at an 80 cm depth in the freeze depths occurring 0e10 cm.As soil temperature decreased in the frozen layer,unfrozen water content(bulk EC)decreased nonlinearly along with the absolute value of soil temperature(|T|),following a power(logarithmic)function.This study provided data that partly elucidate the interactions among permafrost,meadow,and ecohydrological processes in the HAYR.Also,our results can be used as a scientific basis for decision making on the protection and restoration of alpine grasslands,as well as for soil salinization studies.展开更多
Taxonomy plays an important role in understanding the origin, evolution, and ecological functionality of biodiversity. There are large number of unknown species yet to be described by taxonomists, which together with ...Taxonomy plays an important role in understanding the origin, evolution, and ecological functionality of biodiversity. There are large number of unknown species yet to be described by taxonomists, which together with their ecosystem services cannot be effectively protected prior to description. Despite this, taxonomy has been increasingly underrated insufficient funds and permanent positions to retain young talents. Further, the impact factordriven evaluation systems in China exacerbate this downward trend, so alternative evaluation metrics are urgently necessary. When the current generation of outstanding taxonomists retires,there will be too few remaining taxonomists left to train the next generation. In light of these challenges, all co-authors worked together on this paper to analyze the current situation of taxonomy and put out a joint call for immediate actions to advance taxonomy in China.展开更多
Movement in response to mechanical perturbations in plants has long fascinated biologists and nature lovers.Rapid plant movements are of particular interest because they are highly recognizable and challenge the conve...Movement in response to mechanical perturbations in plants has long fascinated biologists and nature lovers.Rapid plant movements are of particular interest because they are highly recognizable and challenge the conventional perception that plants do not move as animals do.Good examples are predation strategies in carnivorous plants,such as sundew,Venus flytrap,and bladderwort[1].展开更多
Techniques of tracking movements of pollen grains are essential for many topics in pollination biology. Pollen transfer of Liriodendron chinense(Hemsl.) Sarg., a hermaphroditic plant, may be both interfloral and intra...Techniques of tracking movements of pollen grains are essential for many topics in pollination biology. Pollen transfer of Liriodendron chinense(Hemsl.) Sarg., a hermaphroditic plant, may be both interfloral and intrafloral pollination. Observations on pollinator movements and flower emasculated experiments in natural populations showed that most of pollen grains deposited on stigmas in a flower are foreign. But it is not certain whether cross pollination or long distance pollen transfer occurs in this insect-pollinated plant. The authors attempt to use random amplified polymorphic DNA (RAPD) loci for paternity analysis to mark pollen dispersal. The results indicated pollen via gene transportation reached at least 100 m away from the pollen source in a selected population. The primary study suggests a larger effective population size in this endangered plant. With its rapid and simple characters, RAPD methods can be a suitable technique for marking pollen flow and able to be widely used in various taxa.展开更多
Importance:Narrative medicine(NM),in which patient stories play a crucial role in their diagnosis and treatment,can potentially support a more holistic approach to patient care than traditional scientiffc ones.However...Importance:Narrative medicine(NM),in which patient stories play a crucial role in their diagnosis and treatment,can potentially support a more holistic approach to patient care than traditional scientiffc ones.However,there are some challenges in the implementation of narrative medicine,for example,differences in understanding illnesses between physicians and patients and physicians’increased workloads and overloaded schedules.This paper ffrst presents a review to explore previous visualization research for narrative medicine to bridge the gap between visualization researchers and narrative medicine experts and explore further visualization opportunities.Highlights:The review is conducted from 2 perspectives:(a)the contexts and domains in which visualization has been explored for narrative medicine and(b)the forms and solutions applied in these studies.Four applied domains are deffned,including understanding patients from narrative records,medical communication,medical conversation training in education,and psychotherapy and emotional wellness enhancement.Conclusions:A future work framework illustrates some opportunities for future research,including groups of speciffc directions and future points for the 4 domains and 3 technological exploration opportunities(combination of narrative and medical data visualization,taskaudience-based visual storytelling,and user-centered interactive visualization).Speciffcally,3 directions of future work in medical communication(asynchronous online physician-patient communication,synchronous face-to-face medical conversation,and medical knowledge dissemination)were concluded.展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2018YFD1000300)the National Natural Science Foundation of China(Grant Nos.32272691 and 32025032)+1 种基金the Grape Breeding Project of Ningxia(Grant No.NXNYYZ202101-04)the Major Program of Technological Innovation in Hubei Province(Grant No.2022BBA0022)。
文摘Cold tolerance is one of the important traits for grapevine,especially in regions with extremely low temperatures in winter.Vitis amurensis is wild species in the Vitis genus with excellent cold hardiness compared with Vitis vinifera.However,metabolites that contribute to the cold tolerance of V.amurensis remain unknown.Here,the metabolomics of buds from V.amurensis‘Zuoshan-1'during cold acclimation(CA)were identified,and cold-sensitive cultivar(V.vinifera‘Jingzaojing')was used as the control.The buds were collected in October,November,and December in 2016 and 2018.The cold hardiness of the buds increased during CA in the two grapevines.However,browning was observed only in V.vinifera buds at temperature below-10℃.Among detected metabolites from buds,443 metabolites were overlapped between two years.Forty-four and thirty differentially accumulated metabolites(DAMs)were identified in V.amurensis and V.vinifera,respectively.Ten DAMs including monoacylglycerol(MAG,18:2)isomer 1,trehalose 6-phosphate,and D-glucose showed identical variations in the two grapevines,indicating conserved CA responses within the Vitis genus.Eighteen DAMs exhibited higher accumulation in V.amurensis than in V.vinifera.Maltotetraose,D-glucoronic acid,L-aspartic acid,azelaic acid,and 4-hydroxybenzoic acid were reported to accumulate during CA in other plants.Enhanced cold tolerance was detected in grapevine leaves with exogenous 5 mmol L^(-1)L-aspartic acid and 1%proanthocyanidins.Potential contributions of other DAMs found in V.amurensis such as Cyanidin 3-O-glucoside need to be further elucidated.Thus,eighteen metabolites accumulated in V.amurensis can be used for practical application in improvement of cold resistance in grapevine.Our findings provide new insights into understanding the cold hardiness of V.amurensis.
文摘Bistate plates have found extensive applications in the domains of smart structures and energy harvesting devices.Most bistable curved plates are characterized by a constant thickness profile.Regrettably,due to the inherent complexity of this problem,relatively little attention has been devoted to this area.In this study,we demonstrate how deep learning can facilitate the discovery of novel plate profiles that cater to multiple objectives,including maximizing stiffness,forward snapping force,and backward snapping force.Our proposed approach is distinguished by its efficiency in terms of low computational energy consumption and high effectiveness.It holds promise for future applications in the design and optimization of multistable structures with diverse objectives,addressing the requirements of various fields.
基金Supported by National Basic Research Program of China(973 Program,Grant No.2012CB026006)
文摘The labyrinth seal in turbomachinery is a key element that restricts leakage flow among rotor-stator clearances from high-pressure regions to low-pressure regions. The fluid-induced forces on the rotor from seals during machine operation must be accurately quantified to predict their dynamic behavior effectively. To understand the fluid-induced force characteristics of the labyrinth seal more fully, the effects of four types of pre-swirls on the leakage, flow field, and fluid-induced force of a rotary straight-through labyrinth gas seal (RSTLGS) were numerically investigated using the proposed steady computational fluid dynamics (CFD) method based on the three-dimensional models of the RSTLGS. The leakage, flow field, and fluid-induced force of the RSTLGS for six axial pre-swirl velocities, four radial preswirl angles, four circumferential positive pre-swirl angles, and four circumferential negative pre-swirl angles were computed under the same geometrical parameters and operational conditions. Mesh analysis ensures the accuracy of the present steady CFD method. The numerical results show that the four types of pre-swirls influence the leakage, flow field, and fluid-induced force of the RSTLGS. The axial pre-swirl velocity remarkably inhibits the fluid-induced force, and the circumferential positive pre-swirl angle and circumferential negative pre-swirl angle remarkably promote the fluid-induced force. The effects of the radial pre-swirl angle on the fluid-induced force are complicated, and the pressure forces and viscous forces show the maximum or minimum values at a specific radial pre-swirl angle. The pre-swirl has a negligible impact on the leakage. The four types of pre-swirls affect the leakage, flow field, and fluidinduced force of the RSTLGS to varying degrees. The pre-swirl is the influence factor affecting the leakage, flow field, and fluid-induced force of the RSTLGS. The conclusions will help to understand the fluid-induced force of labyrinth seals more fully, by providing helpful suggestions for engineering practices and a theoretical basis to analyze the fluid–structure interaction of the seal-rotor system in future research.
基金supported by the Global Change Research Program of China (No. 2010CB951402)the Natural Science Foundation of China (Nos. 91025013, 91325202)+1 种基金the State Key Laboratory of Frozen Soil Engineering (No. SKLFSE-ZY-06), CAS, Chinathe Major Research Plan of the Natural Science Foundation of China (No. 2013CBA01802)
文摘Investigation on spatiotemporal variations of maximum seasonal freeze depth （MSFD） over the Heihe River Basin is of great importance for systematic understanding of regional climate and environmental change, ecological-hydrological processes, water resources assessment, construction and resource development. Based on soil and air temperatures at the meteorological stations of the China Meteorological Administration （CMA） over the Heihe River Basin, MSFDs time series are structured into a composite time series over the 1960-2007 period. Evaluating the averaged MSFD time series for 1960 2007 reveals a statistically significant trend of 4.0 cm/decade or a net change of-19.2 cm for the 48-year period over the basin. The MSFD had significantly negative correlation with mean annual air temperature （MAAT）, winter air temperature, mean annual ground surface temperature （MAGST）, degree days of thawing for the air （DDTa） as well as for the surface （DDTs）, and degree days of freezing for the surface （DDFs）. While there was significantly positive correlation between DDF,. and MSFD time series, MSFD was deeper and changed greatly in the Heihe River source area. It was shallower in the east-central basin and gradually deepened in other sections of the basin. The MSFD distribution pattern in 2003-2005 is consistent with that of averaged degree days of freezing for air （DDFa） in 1960-2007. However, the maximum of MSFD may not be accurate, because there is no long term observation data in the deep seasonally frozen ground regions near the lower boundary of permafrost. With increasing elevation, averaged DDFa increased at a rate of 51.6 ℃-day/100m, therefore, the MSFG and the date reaching MSFG became deeper and later, respectively.
基金supported by the National Key Research and Development Program of China (Grant No. 2018YFD1000300)the National Natural Science Foundation of China (Grant No. 32025032)+1 种基金the Grape Breeding Project of Ningxia (Grant No. NXNYYZ202101-04)Major Program of Technological Innovation in Hubei Province (Grant No. 2019ABA093).
文摘Histone H3 lysine 27 trimethylation(H3K27me3) is a histone modification associated with transcriptional repression. However, insights into the genome-wide pattern of H3K27me3 in grapevines are limited. Here, anti-H3K27 chromatin immunoprecipitation(ChIP), high-throughput sequencing, and transcriptome analysis were performed using leaves of Vitis amurensis. The leaves were treated at 4°C for 2 h and 24 h and used to investigate changes in H3K27me3 under chilling treatment. The results show that H3K27me3 is well-distributed both in gene regions(-50%) and in the intergenic region(-50%) in the grapevine genome(Vitis vinifera ‘Pinot Noir PN40024'). H3K27me3 was found to be localized in8 368 annotated gene regions in all detected samples(leaves at normal temperature and under chilling treatments) and mainly enriched in gene bodies with the adjacent promoter and downstream areas. The short-term chilling treatments(4°C for 2 h) induced 2 793 gains and 305losses in H3K27me3 modification. Subsequently, 97.3% of the alterations were restored to original levels after 24 h treatment. The ChIP-qPCR for five differential peaks showed similar results to the data for ChIP-seq, indicating that the chilling-induced H3K27me3 modification is reliable.Integrative analysis of transcriptome and ChIP-seq results showed that the expression of H3K27me3 target genes was significantly lower than those of non-target genes, indicating transcriptional repression of H3K27me3 in grapevine leaves. Furthermore, histone methylation alterations were detected in 82 genes and were related to either repression or activation of their expression during chilling stress. The findings provide the genome-wide H3K27me3 patterns in grapevines and shed light on uncovering its regulation in chilling stress responses.
基金supported by the Chinese Academy of Sciences Key Research Program (No. KZZD-EW-13)the Natural Science Foundation of China (Nos. 91025013, 91325202)+1 种基金the State Key Laboratory of Frozen Soil Engineering (No. SKLFSE-ZY-06), CASthe Major Research Plan of the National Natural Science Foundation of China (No. 2013CBA01802)
文摘Changes in ground surface thermal regimes play a vital role in surface and subsurface hydrology, ecosystem diversity and productivity, and global thermal, water and carbon budgets as well as climate change. Estimating spring, summer, autumn and winter air temperatures and mean annual air temperature（MAAT） from 1960 through 2008 over the Heihe River Basin reveals a statistically significant trend of 0.31 °C/decade, 0.28 °C/decade, 0.37 °C/decade, 0.50 °C/decade, and 0.37 °C /decade, respectively. The averaged time series of mean annual ground surface temperature（MAGST） and maximum annual ground surface temperature（MaxAGST） for 1972–2006 over the basin indicates a statistically significant trend of 0.58 °C/decade and 1.27 °C/decade, respectively. The minimum annual ground surface temperature（MinAGST） in the same period remains unchanged as a whole. Estimating surface freezing/thawing index as well as the ratio of freezing index to thawing index（RFT） in the period between 1959 and 2006 over the basin indicates a statistically significant trend of-42.5 °C-day/decade, 85.4 °C-day/decade and-0.018/decade, respectively.
文摘As a key supporting equipment for the construction of LNG carriers,the installation platform undertakes the support and guarantee of LNG carrier tank internal construction.This paper takes the secondary shielding installation platform of A-type tank as the object of study,the study firstly considers the semi-rigidity of the nodes and the material nonlinearity based on finite element software,and then the residual structure is calculated using static nonlinear method after single truss,two trusses and three trusses are invalid simultaneously.The research results show that the truss with higher components importance coefficient has greater impact on the residual structure when the truss is invalid;After the 2 trusses of installation platform become invalid completely,the further progressive collapse will not occur;When A1-HJ,A2-HJ and A2-HJ are dismantled at the same time,it will lead to the local progressive damage,which can cause the collapse of large-scale structures.The research findings can support the design and use of the installation platform.
基金Project supported by the K.C.Wong Education FoundationNational Natural Science Foundation of China(U1612442)+3 种基金Key Grant for Creative Research Groups of Guizhou Provincial Education Department(Qian-Jiao-He KY Zi2016047)Young Scientific Talents Growth Project of Guizhou Provincial Education Department(Qian-Jiao-He KY Zi 2016252)Doctoralof Zunyi Normal University(Zun-Shi BS 201815)Science and Technology Project of Guizhou Provincial Science and Technology Department(Qian-Ke-He-Ping-Tai-RenCai 20175727-07)。
文摘As indispensable strategic materials for high-tech industries,rare earth elements and yttrium(REY)have become particularly important in recent years,raising the demand of developing new approaches for reclamation of REY from REY-rich materials such as coal combustion products(CCPs).In this study,five coal-fired power plants(CFPPs)in Guizhou of southwest China were selected for investigating REY concentrations of solid samples,atmospheric emissions,and recovery potentials.REY concentrations of feed fuels are higher in this study(147.2-468.6 mg/kg)than what have been reported previously for coals in China and the world.REY atmospheric emissions are extremely low(38.70-180.11 mg REY/t coal).REY are enriched in bottom ash and fly ash,with average of 658±296 mg/kg and maximum of 1257 mg/kg from the five CFPPs.Relative enrichment factors(REF)of REY in bottom ash and fly ash compared with the feed fuel are 0.86-1.02 and 0.91-1.04,respectively.REY concentrations in desulfurized gypsum are very low(6-17 mg/kg),and that is mostly inherited from limestone.Critical REY(Nd,Eu,Tb,Dy,Y,and Er)in bottom/fly ash account for 34%-39%of the total REY and the outlook coefficients(Cout1)are in the range of 0.89-1.11.This study indicates a promising prospect to reclaim REY from REYrich CCPs(bottom and fly ash)in CFPPs in Guizhou,especially in the central-north Guizhou,although such practices require further technology advancement.
基金supported by National Science Foundation of China(31800176)Sino-Africa Joint Research Center,CAS,China(Y323771W07,SAJC201322).
文摘Aims The aim of this paper is to assess morphological and leaf stoichiometric responses of Dendrosenecio keniensis and Lobelia gregoriana to extreme environmental conditions along an elevation gradient in tropical mountains.Methods In this study,we assessed the variation of the morphological traits,including plant height,leaf area,leaf thickness,leaf dry weight,specific leaf area and the leaf stoichiometry traits nitrogen,carbon and phosphorous of the two endemic species D.keniensis and L.gregoriana.We further explored the relations of these morphological traits to soil organic carbon,soil total nitrogen,soil phosphorous,annual mean temperature,annual mean precipitation,annual total solar radiation,water vapor pressure and the topographic variables aspect,slope and hill shade along the elevation gradient.Ninety 10 m×10 m sampling plots were set up along the elevation gradient ranging from 3500 to 4300 m.We used 1 km×1 km grid cells to rasterize our study area in ArcGIS 10.5 for easy access to data pertaining to the climate of each elevation band.We performed linear regression of the morphological and leaf stoichiometric traits with elevation as explanatory variable.We conducted correlation analysis on the morphological and leaf stoichiometric traits with climatic,soil and topographic variables along the elevation gradient.Important Findings Dendrosenecio keniensis had wool-like pubescent leaves while L.gregoriana had mucilage packed succulent and waxy cuticle leaves to avoid freezing.Both species exhibited reduced metabolic rates as shown by the low leaf phosphorous content.Our results also showed that changes in morphology and leaf stoichiometry were determined by a combination of climate,soil and topographic variables that change along elevation on Mount Kenya.The observed variations in the morphological and leaf stoichiometric traits of D.keniensis and L.gregoriana,which grow side by side along the elevation gradient,were interpreted as adaptation to the harsh environmental conditions.
基金the Strategic Priority Research Pro-gram of Chinese Academy of Sciences(Grant No.XDA20100103)Natural Science Foundation of China(Grant No.41971091).
文摘The coupling effects and mechanisms of water,heat,and salt in frozen soils are considered to be one of the core scientific issues in frozen soil studies.This study was based on in situ observation data of active layer soil volumetric water content(VWC),temperature,and bulk electrical conductivity(EC)obtained at an alpine meadow site from October 2016 to November 2019.The site is located in the headwater area of the Yellow River(HAYR).We analyzed the synergetic variations of active layer soil VWC,temperature,and bulk EC during the freeze and thaw processes and discussed the underlying mechanisms.When the thaw process occurred from 10 to 80 cm depths,the VWC and bulk EC at a 10 cm depth showed syn-chronous high-frequency fluctuations and both increased linearly.The linear decreasing rate of the VWC(bulk EC)at an 80 cm depth in the freeze depths between 0 and 40 cm was 2(1.6e2.3)times that of the VWC(bulk EC)at an 80 cm depth in the freeze depths occurring 0e10 cm.As soil temperature decreased in the frozen layer,unfrozen water content(bulk EC)decreased nonlinearly along with the absolute value of soil temperature(|T|),following a power(logarithmic)function.This study provided data that partly elucidate the interactions among permafrost,meadow,and ecohydrological processes in the HAYR.Also,our results can be used as a scientific basis for decision making on the protection and restoration of alpine grasslands,as well as for soil salinization studies.
基金mainly supported by National Science Fund for Distinguished Young Scholars (31625024)a grant (2008DP173354) from the Key Laboratory of the Zoological Systematics and Evolution of the Chinese Academy of Sciences。
文摘Taxonomy plays an important role in understanding the origin, evolution, and ecological functionality of biodiversity. There are large number of unknown species yet to be described by taxonomists, which together with their ecosystem services cannot be effectively protected prior to description. Despite this, taxonomy has been increasingly underrated insufficient funds and permanent positions to retain young talents. Further, the impact factordriven evaluation systems in China exacerbate this downward trend, so alternative evaluation metrics are urgently necessary. When the current generation of outstanding taxonomists retires,there will be too few remaining taxonomists left to train the next generation. In light of these challenges, all co-authors worked together on this paper to analyze the current situation of taxonomy and put out a joint call for immediate actions to advance taxonomy in China.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2019QZKK0502)the Natural Science Foundation of Hubei Province(2019CFA066)the Plateau Ecology Youth Innovative Fund of Wuhan University(413100105)。
文摘Movement in response to mechanical perturbations in plants has long fascinated biologists and nature lovers.Rapid plant movements are of particular interest because they are highly recognizable and challenge the conventional perception that plants do not move as animals do.Good examples are predation strategies in carnivorous plants,such as sundew,Venus flytrap,and bladderwort[1].
文摘Techniques of tracking movements of pollen grains are essential for many topics in pollination biology. Pollen transfer of Liriodendron chinense(Hemsl.) Sarg., a hermaphroditic plant, may be both interfloral and intrafloral pollination. Observations on pollinator movements and flower emasculated experiments in natural populations showed that most of pollen grains deposited on stigmas in a flower are foreign. But it is not certain whether cross pollination or long distance pollen transfer occurs in this insect-pollinated plant. The authors attempt to use random amplified polymorphic DNA (RAPD) loci for paternity analysis to mark pollen dispersal. The results indicated pollen via gene transportation reached at least 100 m away from the pollen source in a selected population. The primary study suggests a larger effective population size in this endangered plant. With its rapid and simple characters, RAPD methods can be a suitable technique for marking pollen flow and able to be widely used in various taxa.
基金funded by NSFC 62272012,Wuhan East Lake High-Tech Development Zone(also known as the Optics Valley of China,or OVC)National Comprehensive Experimental Base for Governance of Intelligent Society.
文摘Importance:Narrative medicine(NM),in which patient stories play a crucial role in their diagnosis and treatment,can potentially support a more holistic approach to patient care than traditional scientiffc ones.However,there are some challenges in the implementation of narrative medicine,for example,differences in understanding illnesses between physicians and patients and physicians’increased workloads and overloaded schedules.This paper ffrst presents a review to explore previous visualization research for narrative medicine to bridge the gap between visualization researchers and narrative medicine experts and explore further visualization opportunities.Highlights:The review is conducted from 2 perspectives:(a)the contexts and domains in which visualization has been explored for narrative medicine and(b)the forms and solutions applied in these studies.Four applied domains are deffned,including understanding patients from narrative records,medical communication,medical conversation training in education,and psychotherapy and emotional wellness enhancement.Conclusions:A future work framework illustrates some opportunities for future research,including groups of speciffc directions and future points for the 4 domains and 3 technological exploration opportunities(combination of narrative and medical data visualization,taskaudience-based visual storytelling,and user-centered interactive visualization).Speciffcally,3 directions of future work in medical communication(asynchronous online physician-patient communication,synchronous face-to-face medical conversation,and medical knowledge dissemination)were concluded.
