Landslides occurring in sensitive clay often result in widespread destruction,posing a significant risk to human lives and property due to the substantial decrease in undrained shear strength during deformation.Assess...Landslides occurring in sensitive clay often result in widespread destruction,posing a significant risk to human lives and property due to the substantial decrease in undrained shear strength during deformation.Assessing the consequences of these landslides is challenging and necessitates robust numerical methods to comprehensively investigate their failure mechanisms.While studies have extensively explored upward progressive landslides in sensitive clays,understanding downward progressive cases remains limited.In this study,we utilised the nodal integration-based particle finite element method(NPFEM)with a nonlinear strain-softening model to analyse downward progressive landslides in sensitive clay on elongated slopes,induced by surcharge loads near the crest.We focused on elucidating the underlying failure mechanisms and evaluating the effects of different soil parameters and strainsoftening characteristics.The simulation results revealed the typical pattern for downward landslides,which typically start with a localised failure in proximity to the surcharge loads,followed by a combination of different types of failure mechanisms,including single flow slides,translational progressive landslides,progressive flow slides,and spread failures.Additionally,inclined shear bands occur within spread failures,often adopting distinctive ploughing patterns characterised by triangular shapes.The sensitive clay thickness at the base,the clay strength gradient,the sensitivity,and the softening rate significantly influence the failure mechanisms and the extent of diffused displacement.Remarkably,some of these effects mirror those observed in upward progressive landslides,underscoring the interconnectedness of these phenomena.This study contributes valuable insights into the complex dynamics of sensitive clay landslides,shedding light on the intricate interplay of factors governing their behaviour and progression.展开更多
BACKGROUND Esophageal stricture ranks among the most significant complications following endoscopic submucosal dissection(ESD).Excessive fibrotic repair is a typical pathological feature leading to stenosis after ESD....BACKGROUND Esophageal stricture ranks among the most significant complications following endoscopic submucosal dissection(ESD).Excessive fibrotic repair is a typical pathological feature leading to stenosis after ESD.AIM To examine the effectiveness and underlying mechanism of Kangfuxin solution(KFX)in mitigating excessive fibrotic repair of the esophagus post-ESD.METHODS Pigs received KFX at 0.74 mL/kg/d for 21 days after esophageal full circumferential ESD.Endoscopic examinations occurred on days 7 and 21 post-ESD.In vitro,recombinant transforming growth factor(TGF)-β1(5 ng/mL)induced a fibrotic microenvironment in primary esophageal fibroblasts(pEsF).After 24 hours of KFX treatment(at 1.5%,1%,and 0.5%),expression ofα-smooth muscle actin-2(ACTA2),fibronectin(FN),and type collagen I was assessed.Profibrotic signaling was analyzed,including TGF-β1,Smad2/3,and phosphor-smad2/3(p-Smad2/3).RESULTS Compared to the Control group,the groups treated with KFX and prednisolone exhibited reduced esophageal stenosis,lower weight loss rates,and improved food tolerance 21 d after ESD.After treatment,Masson staining revealed thinner and less dense collagen fibers in the submucosal layer.Additionally,the expression of fibrotic effector molecules was notably inhibited.Mechanistically,KFX downregulated the transduction levels of fibrotic functional molecules such as TGF-β1,Smad2/3,and p-Smad2/3.In vitro,pEsF exposed to TGF-β1-induced fibrotic microenvironment displayed increased fibrotic activity,which was reversed by KFX treatment,leading to reduced activation of ACTA2,FN,and collagen I.The 1.5%KFX treatment group showed decreased expression of p-Smad 2/3 in TGF-β1-activated pEsF.CONCLUSION KFX showed promise as a therapeutic option for post-full circumferential esophageal ESD strictures,potentially by suppressing fibroblast fibrotic activity through modulation of the TGF-β1/Smads signaling pathway.展开更多
Objective:Small cell lung cancer(SCLC)is commonly recognized as the most fatal lung cancer type.Despite substantial advances in immune checkpoint blockade therapies for treating solid cancers,their benefits are limite...Objective:Small cell lung cancer(SCLC)is commonly recognized as the most fatal lung cancer type.Despite substantial advances in immune checkpoint blockade therapies for treating solid cancers,their benefits are limited to a minority of patients with SCLC.In the present study,novel indicators for predicting the outcomes and molecular targets for SCLC treatment were elucidated.Methods:We conducted bioinformatics analysis to identify the key genes associated with tumor-infiltrating lymphocytes in SCLC.The functional role of the key gene identified in SCLC was determined both in vitro and in vivo.Results:A significant correlation was observed between patient survival and CD56dim natural killer(NK)cell proportion.Furthermore,we noted that the hub gene ubiquitin-specific protease 1(USP1)is closely correlated with both CD56dim NK cells and overall survival in SCLC.Bioinformatics analysis revealed that USP1 is upregulated in SCLC.In addition,gene set enrichment analysis revealed that USP1 overexpression hinders NK cell-mediated immune responses.By co-cultivating NK-92 cells with SCLC cells,we demonstrated that NK cell cytotoxicity against SCLC could be improved either via USP1 knock-down or pharmacological inhibition.Furthermore,using a nude-mice xenograft tumor model,we noted that USP1 inhibition effectively suppressed tumor proliferation and increased the expression of NK cell-associated markers.Conclusions:Our study findings highlight the importance of NK cells in regulating SCLC.USP1 overexpression can inhibit NK cell-mediated immunity;therefore,USP1 may serve not only as a prognostic biomarker but also as a potential molecular target of SCLC therapy.展开更多
The majority(up to 90%)of riverine materials is transported from the continent to the ocean mainly in flood events.It is thus crucial to characterize the geochemistry of elements and their flux in river system in orde...The majority(up to 90%)of riverine materials is transported from the continent to the ocean mainly in flood events.It is thus crucial to characterize the geochemistry of elements and their flux in river system in order to better constrain their global biogeochemical cycling and impact on the oceanic ecosystem.However,the geochemical behavior including the distribution,migration and partitioning of typical metal elements amongst diff erent phases,during hydrodynamic flood event remains still to be well explored.Here,we investigated the geochemical behaviors of typical metal elements in dissolved phase and suspended particulate matter collected from a single flood event in the natural Chishui River,Southwest China.The results showed clearly that the geochemistry of metal elements was largely controlled by the hydrodynamic eff ect,of which the diff erent flowrates introduce a natural sorting of diff erent mineral particles transported at diff erent flood stages,depending on their shape,size and density.The maximum concentrations of alkaline and alkaline earth metals(Li,Mg,K,Rb and Sr)in SPM appeared before the flood peak,which was largely controlled by aluminosilicate minerals.However,transition metals(Cr,Mn,Fe,Ni and Cu)showed their abundance peaks lagging behind the flowrate summit,as a result of the late arrival of coarse particles or heavy minerals,evidenced by the mineralogical phase analysis.In addition,the distribution coe fficient(K_(d))between particulate and dissolved loads were lower and stable for soluble alkali/alkaline earth metals which could be aff ected by pH,while higher and fluctuant for transition metals that were largely influenced by SPM content.Overall,the present study reveals clear eff ects of hydrodynamic sorting on the geochemistry of metal elements during the flood event of the natural Chishui River,which should be taken into account when characterizing the riverine flux and their impact on marine ecosystem.展开更多
Agricultural intensification has led to an increase in monoculture and the use of chemical pesticides,resulting in a decline in biodiversity and a reduction in ecosystem services,particularly biological pest managemen...Agricultural intensification has led to an increase in monoculture and the use of chemical pesticides,resulting in a decline in biodiversity and a reduction in ecosystem services,particularly biological pest management.However,studies have shown that agroforestry can not only improve land productivity and biodiversity but also regulate some ecosystem services.This study reviews the impacts of physical and biological factors on herbivorous pests,parasites,and predatory natural enemies in fruit-crop agroforestry systems.Fruit-crop agroforestry systems provide high spatial heterogeneity by altering crop layouts,regulating the microclimate and soil quality,and offering food resources and shelter for natural enemies,thus promoting biological pest control.This enhances biological control and makes the agrocomplex system an effective tool for sustainable agriculture.Our research shows that volatile plant substances attract or repel pests and natural enemies based on the characteristics of the insects themselves.When scientifically designed,fruit-crop agroforestry systems provide high spatial heterogeneity and favorable microclimatic conditions,which enhance biological pest control and make the agroforestry system an effective tool for sustainable agriculture.Our research shows that fruit-crop agroforestry systems can provide richer food resources and habitat,enhancing biological pest control and improving pest management.展开更多
With growing concerns for global warming and environmental issues,the research community has contributed significantly to green technology in the area of material science through the development of natural fiber-reinf...With growing concerns for global warming and environmental issues,the research community has contributed significantly to green technology in the area of material science through the development of natural fiber-reinforced polymer composites(NFRPC).Polymers serve as the matrix in NFRPC,while natural fibers serve as the reinforcing materials.Demand for high-performing materials made with natural resources is growing continuously.Natural fiber-reinforced polymer composites are sustainable biocomposites fabricated with natural fibers embedded with a polymer matrix.They offer a wide range of advantages,including a low weight-to-strength ratio,high flexural strength,damping properties,and resistance to corrosion,wear,and impact.Understanding the basic properties,characteristics,and processing techniques for natural fibers is important to consider their use as raw materials for high-quality biocomposite.Natural fibers come with low density and a high strengthto-weight ratio,allowing them to be a potential reinforcement for low-weight composites.This article attempts to present a comprehensive review of the available natural fibers,their classification,types,structures,physical properties,characteristics,and mechanical properties.Natural fibers are hydrophilic in nature and require physical and chemical treatment prior to their application as reinforcing material.This review will also cover the required physical and chemical treatments of natural fibers for fabricating biocomposites.展开更多
Tumors,due to their diversity and heterogeneity,pose a significant threat to human health.Multidrug resistance is a prevalent and grave issue in clinical treatment,resulting in treatment failure and cancer recurrence....Tumors,due to their diversity and heterogeneity,pose a significant threat to human health.Multidrug resistance is a prevalent and grave issue in clinical treatment,resulting in treatment failure and cancer recurrence.This resistance renders conventional drug therapies ineffective,presenting a substantial challenge to human health and medical care.Exploring natural products as potential sources for anti-cancer drugs could lead to the development of innovative and efficacious cancer treatments.This article aims to investigate the health implications of natural products(such as paclitaxel,podophyllotoxin,homoharringtonine,camptothecin,and vinblastine)in the discovery of anti-cancer drugs while discussing the methods and progress made in researching novel anti-cancer drugs derived from natural products.The paper discusses the diversity,intricate structures,and target affinity of natural products along with their structural modification techniques,combination therapies utilization possibilities with prodrugs or nanoparticles.Additionally,considering the escalating multidrug resistance observed in tumors nowadays;certain natural products offer new insights and approaches for discovering effective anti-tumor drugs that are crucial for addressing global public health challenges.The challenges faced by natural products during drug development including issues related to bioavailability toxicity concerns as well as limited resources are examined thoroughly.Potential opportunities current issues along with future challenges are highlighted aiming at facilitating the clinical translation of original anti-cancer drugs using natural products.展开更多
The impacts of natural boulders carried by debris flows pose serious risks to the safety and reliability of structures and buildings.Natural boulders can be highly random and unpredictable.Consequently,boulder control...The impacts of natural boulders carried by debris flows pose serious risks to the safety and reliability of structures and buildings.Natural boulders can be highly random and unpredictable.Consequently,boulder control during debris flows is crucial but difficult.Herein,an eco-friendly control system featuring anchoring natural boulders(NBs)with(negative Poisson's ratio)NPR anchor cables is proposed to form an NB-NPR baffle.A series of flume experiments are conducted to verify the effect of NB-NPR baffles on controlling debris flow impact.The deployment of NB-NPR baffles substantially influences the kinematic behavior of a debris flow,primarily in the form of changes in the depositional properties and impact intensities.The results show that the NB-NPR baffle matrix successfully controls boulder mobility and exhibits positive feedback on solid particle deposition.The NB-NPR baffle group exhibits a reduction in peak impact force ranging from 29%to 79%compared to that of the control group in the basic experiment.The NPR anchor cables play a significant role in the NB-NPR baffle by demonstrating particular characteristics,including consistent resistance,large deformation,and substantial energy absorption.The NB-NPR baffle innovatively utilizes the natural boulders in a debris flow gully by converting destructive boulders into constructive boulders.Overall,this research serves as a basis for future field experiments and applications.展开更多
Background:Cardiovascular and cerebrovascular diseases are significant health threats that have been found to involve ferroptosis in related cells.This study aims to comprehensively examine the role and mechanism of n...Background:Cardiovascular and cerebrovascular diseases are significant health threats that have been found to involve ferroptosis in related cells.This study aims to comprehensively examine the role and mechanism of natural products,derived from traditional Chinese herbal medicines,in intervening in ferroptosis from the perspective of cardiovascular and cerebrovascular aspects.Methods:A literature survey was conducted using Scopus,Pubmed,Reaxys,and Google Scholar databases to review studies on natural products(such as baicalin,puerarin,and ginsenosides)derived from herbs like scutellaria baicalensis,pueraria lobata,ginseng,panax quinquefolium,and panax notoginseng.The focus was on their potential as drugs for the treatment of cardiovascular and cerebrovascular diseases,particularly their ability to inhibit ferroptosis.Results:The review revealed that various natural products exhibit disease protection and prevention properties,inhibiting ferroptosis through diverse pathways and targets in cardiovascular and cerebrovascular diseases.The involvement of these natural products in key pathways associated with ferroptosis,including amino acid metabolism,iron metabolism,and lipid peroxidation,was elucidated.Notably,tanshinone IIA,resveratrol,astragaioside IV,and vitexin were found to regulate ferroptosis in both cardiovascular and cerebrovascular cells.Additionally,the impact of these natural products on key targets of ferroptosis,such as SLC7A11,DMTI,TfRI,Nrf2,HO-1,GPX4,NCOA4,and LOX,was discussed.Conclusion:This study provides a comprehensive understanding of the role and mechanism of natural products in intervening in ferroptosis related to cardiovascular and cerebrovascular diseases.The findings pave the way for potential future treatments targeting ferroptosis in these diseases.展开更多
Economic growth affects natural resources and the environment directly and indirectly;however,the exact role that natural resources play in environmental sustainability remains unknown.This paper revisits the relation...Economic growth affects natural resources and the environment directly and indirectly;however,the exact role that natural resources play in environmental sustainability remains unknown.This paper revisits the relationship between natural resources and CO_(2)emissions by considering the role of green finance vis-à-vis the aggregated and disaggregated analysis.Empirical panel data estimation analyzes a sample of emerging countries over the 2001-2019 period using the recently developed econometric cross-sectional auto-regressive distributed lag(CS-ARDL)technique.The findings show that natural resource components(natural gas,mineral rent,oil rent,and coal rent)are negatively associated with environmental pollution.In contrast,overall natural resource consumption helps reduce carbon emissions.However,we find that green finance contributes to carbon emission reduction.In contrast,education causes pollution by contributing to carbon emissions.We offer policy recommendations about the effectiveness of green financing for the sustainable use of natural resources in diminishing pollution.展开更多
In the contemporary medical landscape,the burgeoning interest in natural therapies,particularly for managing gastrointestinal disorders,has brought traditional Chinese medicine(TCM)to the forefront.This article explai...In the contemporary medical landscape,the burgeoning interest in natural therapies,particularly for managing gastrointestinal disorders,has brought traditional Chinese medicine(TCM)to the forefront.This article explains the core principles and clinical applications of TCM in treating these conditions,furthering the discourse through an examination of integrated TCM strategies,as demonstrated in the study by Zhou et al.While TCM has shown promising clinical outcomes,it encounters significant hurdles in standardization,mechanistic research,and clinical validation.Future investigations should aim to solidify the scientific underpinnings of TCM and expand its use in gastrointestinal disease management,striving for a seamless fusion of traditional and contemporary medical practices.展开更多
The attenuation of the acoustic activity in marble specimens under uniaxial compressive loadingunloading loops is quantified in juxtaposition to that of the electric activity.In parallel,the existence of"pre-fail...The attenuation of the acoustic activity in marble specimens under uniaxial compressive loadingunloading loops is quantified in juxtaposition to that of the electric activity.In parallel,the existence of"pre-failure indiceso"warning about entrance into a critical stage,that of impending fracture,is explored.The acoustic activity is quantified in terms of the normalized number of acoustic hits,their average rate of production and their cumulative energy,and,the cumulative counts and their average rate of change.The electric activity is studied in terms of the pressure stimulated currents and the electric charge released.The analysis revealed that the acoustic and electric activities are linearly correlated to each other,suggesting that they are different manifestations of the same damage mechanisms.In addition,Kaiser's effect,governing the acoustic activity,is found to govern,also,the electric activity.Moreover,it is concluded that entrance into the critical stage is safely predicted by means of a simple criterion,based on the evolution of the average rate of change of the normalized cumulative counts in the natural time domain.These predictions are almost identical with those of the criterion based on the "varianceo" and the "entropies" of the time series of acoustic events in this domain.展开更多
Hydraulic fracturing is a crucial technique for efficient development of coal reservoirs.Coal rocks typically contain a high density of natural fractures,which serve as conduits for fracturing fluid.Upon injection,the...Hydraulic fracturing is a crucial technique for efficient development of coal reservoirs.Coal rocks typically contain a high density of natural fractures,which serve as conduits for fracturing fluid.Upon injection,the fluid infiltrates these natural fractures and leaks out,resulting in complex fracture morphology.The prediction of hydraulic fracture network propagation for coal reservoirs has important practical significance for evaluating hydraulic fracturing.This study proposes a novel inversion method for predicting fracture networks in coal reservoirs,explicitly considering the distribution of natural fractures.The method incorporates three distinct natural fracture opening modes and employs a fractal probability function to constrain fracture propagationmorphology.Based on thismethod,the study compares hydraulic fracture networkmorphologies in coal reservoirs with andwithout the presence of natural fractures.Theresults showthatwhile both reservoir types exhibitmulti-branch fracture networks,reservoirs containing natural fractures demonstrate greater branching and a larger stimulated reservoir volume(SRV).Additionally,the study employs a fractal dimension calculation method to quantitatively describe the geometric distribution characteristics of fractures.The analysis reveals that the geometry and distribution of natural fractures,as well as reservoir geological parameters,significantly influence the fracture networkmorphology and fractal dimension.The contact angle between natural and hydraulic fractures affects propagation direction;specifically,when the contact angle isπ/2,the fractal dimension of the hydraulic fracture network is maximized.Moreover,smaller lengths and spacings of natural fracture led to higher fractal dimensions,which can significantly increase the SRV.The proposed method offers an effective tool for evaluating the hydraulic fracturing of coal reservoirs.展开更多
The formation of Mesozoic natural gas in the Pengyang area of southwestern Ordos Basin is discussed,from the perspective of microbial community characteristics,in order to clarify the relationship between the origin o...The formation of Mesozoic natural gas in the Pengyang area of southwestern Ordos Basin is discussed,from the perspective of microbial community characteristics,in order to clarify the relationship between the origin of natural gas and its associated indigenous microbial community.The types and diversity of indigenous microbial communities associated with the oil reservoir were studied by means of collecting reservoir formation water samples from exploration wells.The indigenous microbial communities in the Chang 8 member of the Yanchang Formation were primarily distributed within Proteobacteria and Firmicutes,including the specific species and genera of Methylobacter,Pseudomonas,Haibacter,Toxobacillus,Acinetobacter and Adura actinomyces.The results of diversity analysis shows that the number of common genes was 5448,while the number of unique genes and information was less.This reflects the fact that the strata in the study area are relatively closed and not invaded by external water sources,which leads to the development of biological community diversity.In conjunction with the analysis of geochemical characteristics of oil and gas reservoirs in this area,this indicates that the study area possesses the necessary geological conditions for microbial degradation.It is the first time that the species and diversity of the indigenous microbial community in the Ordos Basin have been analyzed,showing that microbial degradation is the main cause of natural gas formation here,changes the characteristics of crude oil in this area and provides first-hand information on the impact of indigenous microorganisms on the reservoir.展开更多
Any new report on the anticancer properties of natural products always awakens new satisfaction and hope about the role of the international scientific community in its continuous contributions to human health,particu...Any new report on the anticancer properties of natural products always awakens new satisfaction and hope about the role of the international scientific community in its continuous contributions to human health,particularly when those reports contribute to both the understanding and therapeutics of cancer.For many de-cades,natural products have been pivotal in drug discovery programs because they offer a diverse array of anticancer therapeutic possibilities.Recently,two manuscripts published in the World Journal of Gastrointestinal Oncology added new data to the already extensive body of anticancer preclinical evidence for resvera-trol and senegenin,two compounds widely present in herbal preparations used in traditional Chinese medicine.The first one,with comprehensive and recognized anticancer properties,and the second one,shows a compelling body of evidence supporting its neuroprotective effects,but with emerging anticancer activities.Natural products have become key elements in the expanding and dynamic field of anticancer drug discovery.However,urgent and collective efforts are still needed to bridge the gap between preclinical and clinical research and thus bring new anticancer therapeutic breakthroughs.展开更多
Using natural gas(NG)as the primary fuel helps alleviate the fossil fuel crisis while reducing engine soot and nitrogen oxide(NO_(X))emissions.In this paper,the influences of a novel split injection concept on an NG h...Using natural gas(NG)as the primary fuel helps alleviate the fossil fuel crisis while reducing engine soot and nitrogen oxide(NO_(X))emissions.In this paper,the influences of a novel split injection concept on an NG high pressure direct injection(HPDI)engine are examined.Four typical split injection strategies,namely split pre-injection of pilot diesel(PD)and NG,split post-injection of PD and NG,split pre-injection of NG,and split post-injection of PD,were developed to investigate the influences on combustion and emissions.Results revealed that split pre injection of NG enhanced the atomization of PD,whereas the split post-injection of NG lowered the temperature in the core region of the PD spray,resulting in the deterioration of combustion.The effect of the split injection strategy on indicated thermal efficiency exceeded 7.5%.Split pre-injection was favorable to enhancing thermal efficiency,whereas split post-injection was not.Ignition delay,combustion duration,and premixed combustion time proportion were affected by injection strategies by 3.8%,50%,and 19.7%,respectively.Split pre-injection increased CH_(4) emission in the exhaust.Split post-injection,especially split post-injection of PD and NG,reduced the unburned CH_(4) emission by approximately 30%.When the split post-injection ratio was less than 30%,the trade-off between NO_(X) and soot was interrupted.The distribution range of hydroxyl radicals was expanded by pre-injection,and NO_(X) was generated in the region where the NG jet hit the wall.This paper provides valuable insights into the optimization of HPDI injection parameters.展开更多
Extracted natural gas hydrate is a multi-phase and multi-component mixture,and its complex composition poses significant challenges for transmission and transportation,including phase changes following extraction and ...Extracted natural gas hydrate is a multi-phase and multi-component mixture,and its complex composition poses significant challenges for transmission and transportation,including phase changes following extraction and sediment deposition within the pipeline.This study examines the flow and heat transfer characteristics of hydrates in a riser,focusing on the multi-phase flow behavior of natural gas hydrate in the development riser.Additionally,the effects of hydrate flow and seawater temperature on heat exchange are analyzed by simulating the ambient temperature conditions of the South China Sea.The findings reveal that the increase in unit pressure drop is primarily attributed to higher flowvelocities,which result in increased friction of the hydrate flowwithin the development riser.For example,at a hydrate volume fraction of 10%,the unit pressure drop rises by 166.65%and 270.81% when the average inlet velocity is increased from1.0 to 3.0m/s(a two-fold increase)and 5.0 m/s(a four-fold increase),respectively.Furthermore,the riser outlet temperature rises with increasing hydrate flowrates.Under specific heat loss conditions,the flowratemust exceed a minimum threshold to ensure safe transportation.The study also indicates that the riser outlet temperature increases with higher seawater temperatures.Within the seawater temperature range of 5℃ to 15℃,the heat transfer efficiency is reduced compared to the range of 15℃ to 20℃.This discrepancy is due to the fact that as the seawater temperature rises,the convective heat transfer coefficient between the hydrate and the inner wall of the riser also increases,leading to improved overall heat transfer between the hydrate and the pipeline.展开更多
The emergence of adversarial examples has revealed the inadequacies in the robustness of image classification models based on Convolutional Neural Networks (CNNs). Particularly in recent years, the discovery of natura...The emergence of adversarial examples has revealed the inadequacies in the robustness of image classification models based on Convolutional Neural Networks (CNNs). Particularly in recent years, the discovery of natural adversarial examples has posed significant challenges, as traditional defense methods against adversarial attacks have proven to be largely ineffective against these natural adversarial examples. This paper explores defenses against these natural adversarial examples from three perspectives: adversarial examples, model architecture, and dataset. First, it employs Class Activation Mapping (CAM) to visualize how models classify natural adversarial examples, identifying several typical attack patterns. Next, various common CNN models are analyzed to evaluate their susceptibility to these attacks, revealing that different architectures exhibit varying defensive capabilities. The study finds that as the depth of a network increases, its defenses against natural adversarial examples strengthen. Lastly, Finally, the impact of dataset class distribution on the defense capability of models is examined, focusing on two aspects: the number of classes in the training set and the number of predicted classes. This study investigates how these factors influence the model’s ability to defend against natural adversarial examples. Results indicate that reducing the number of training classes enhances the model’s defense against natural adversarial examples. Additionally, under a fixed number of training classes, some CNN models show an optimal range of predicted classes for achieving the best defense performance against these adversarial examples.展开更多
In this study,the evidence-based design(EBD)of naturalized decoration in hematopoietic stem cell transplantation(HSCT)wards of Peking University First Hospital was explored to improve patients’psychological state and...In this study,the evidence-based design(EBD)of naturalized decoration in hematopoietic stem cell transplantation(HSCT)wards of Peking University First Hospital was explored to improve patients’psychological state and rehabilitation environment by introducing natural elements.Based on questionnaire surveys and literature research,the EBD method was adopted to propose a naturalized decoration scheme for HSCT wards,and a satisfaction evaluation was conducted after construction and use.The research results show that naturalized decoration can effectively enhance the satisfaction and comfort of patients and medical staff,verifying its positive effects in HSCT wards.展开更多
Rural education in China faces significant challenges,including limited resources,declining student enrollment,and frequent school closures.This paper examines the educational leadership and management strategies empl...Rural education in China faces significant challenges,including limited resources,declining student enrollment,and frequent school closures.This paper examines the educational leadership and management strategies employed by Simin Primary School,a century-old rural institution in Zhuji City,which has successfully revitalized its community and attracted students through the innovative practice of nature education.By leveraging local cultural and environmental resources,the school has established a sustainable model for small rural schools.展开更多
基金support provided by the UK Engineering and Physical Sciences Research Council(EP/V012169/1).
文摘Landslides occurring in sensitive clay often result in widespread destruction,posing a significant risk to human lives and property due to the substantial decrease in undrained shear strength during deformation.Assessing the consequences of these landslides is challenging and necessitates robust numerical methods to comprehensively investigate their failure mechanisms.While studies have extensively explored upward progressive landslides in sensitive clays,understanding downward progressive cases remains limited.In this study,we utilised the nodal integration-based particle finite element method(NPFEM)with a nonlinear strain-softening model to analyse downward progressive landslides in sensitive clay on elongated slopes,induced by surcharge loads near the crest.We focused on elucidating the underlying failure mechanisms and evaluating the effects of different soil parameters and strainsoftening characteristics.The simulation results revealed the typical pattern for downward landslides,which typically start with a localised failure in proximity to the surcharge loads,followed by a combination of different types of failure mechanisms,including single flow slides,translational progressive landslides,progressive flow slides,and spread failures.Additionally,inclined shear bands occur within spread failures,often adopting distinctive ploughing patterns characterised by triangular shapes.The sensitive clay thickness at the base,the clay strength gradient,the sensitivity,and the softening rate significantly influence the failure mechanisms and the extent of diffused displacement.Remarkably,some of these effects mirror those observed in upward progressive landslides,underscoring the interconnectedness of these phenomena.This study contributes valuable insights into the complex dynamics of sensitive clay landslides,shedding light on the intricate interplay of factors governing their behaviour and progression.
基金Supported by Science and Technology Department of Sichuan Province,No.2020YFS0376National Natural Science Foundation of China,No.81900599Science and Technology Program of Hospital of TCM,Southwest Medical University,No.2022-CXTD-01.
文摘BACKGROUND Esophageal stricture ranks among the most significant complications following endoscopic submucosal dissection(ESD).Excessive fibrotic repair is a typical pathological feature leading to stenosis after ESD.AIM To examine the effectiveness and underlying mechanism of Kangfuxin solution(KFX)in mitigating excessive fibrotic repair of the esophagus post-ESD.METHODS Pigs received KFX at 0.74 mL/kg/d for 21 days after esophageal full circumferential ESD.Endoscopic examinations occurred on days 7 and 21 post-ESD.In vitro,recombinant transforming growth factor(TGF)-β1(5 ng/mL)induced a fibrotic microenvironment in primary esophageal fibroblasts(pEsF).After 24 hours of KFX treatment(at 1.5%,1%,and 0.5%),expression ofα-smooth muscle actin-2(ACTA2),fibronectin(FN),and type collagen I was assessed.Profibrotic signaling was analyzed,including TGF-β1,Smad2/3,and phosphor-smad2/3(p-Smad2/3).RESULTS Compared to the Control group,the groups treated with KFX and prednisolone exhibited reduced esophageal stenosis,lower weight loss rates,and improved food tolerance 21 d after ESD.After treatment,Masson staining revealed thinner and less dense collagen fibers in the submucosal layer.Additionally,the expression of fibrotic effector molecules was notably inhibited.Mechanistically,KFX downregulated the transduction levels of fibrotic functional molecules such as TGF-β1,Smad2/3,and p-Smad2/3.In vitro,pEsF exposed to TGF-β1-induced fibrotic microenvironment displayed increased fibrotic activity,which was reversed by KFX treatment,leading to reduced activation of ACTA2,FN,and collagen I.The 1.5%KFX treatment group showed decreased expression of p-Smad 2/3 in TGF-β1-activated pEsF.CONCLUSION KFX showed promise as a therapeutic option for post-full circumferential esophageal ESD strictures,potentially by suppressing fibroblast fibrotic activity through modulation of the TGF-β1/Smads signaling pathway.
基金supported by grants from the Dongguan Science and Technology of Social Development Program(No.20231800940192)the Talent Development Foundation of the First Dongguan Affiliated Hospital of Guangdong Medical University(No.PU2023002).
文摘Objective:Small cell lung cancer(SCLC)is commonly recognized as the most fatal lung cancer type.Despite substantial advances in immune checkpoint blockade therapies for treating solid cancers,their benefits are limited to a minority of patients with SCLC.In the present study,novel indicators for predicting the outcomes and molecular targets for SCLC treatment were elucidated.Methods:We conducted bioinformatics analysis to identify the key genes associated with tumor-infiltrating lymphocytes in SCLC.The functional role of the key gene identified in SCLC was determined both in vitro and in vivo.Results:A significant correlation was observed between patient survival and CD56dim natural killer(NK)cell proportion.Furthermore,we noted that the hub gene ubiquitin-specific protease 1(USP1)is closely correlated with both CD56dim NK cells and overall survival in SCLC.Bioinformatics analysis revealed that USP1 is upregulated in SCLC.In addition,gene set enrichment analysis revealed that USP1 overexpression hinders NK cell-mediated immune responses.By co-cultivating NK-92 cells with SCLC cells,we demonstrated that NK cell cytotoxicity against SCLC could be improved either via USP1 knock-down or pharmacological inhibition.Furthermore,using a nude-mice xenograft tumor model,we noted that USP1 inhibition effectively suppressed tumor proliferation and increased the expression of NK cell-associated markers.Conclusions:Our study findings highlight the importance of NK cells in regulating SCLC.USP1 overexpression can inhibit NK cell-mediated immunity;therefore,USP1 may serve not only as a prognostic biomarker but also as a potential molecular target of SCLC therapy.
基金National Natural Science Foundation of China,42103008,Hongming Cai。
文摘The majority(up to 90%)of riverine materials is transported from the continent to the ocean mainly in flood events.It is thus crucial to characterize the geochemistry of elements and their flux in river system in order to better constrain their global biogeochemical cycling and impact on the oceanic ecosystem.However,the geochemical behavior including the distribution,migration and partitioning of typical metal elements amongst diff erent phases,during hydrodynamic flood event remains still to be well explored.Here,we investigated the geochemical behaviors of typical metal elements in dissolved phase and suspended particulate matter collected from a single flood event in the natural Chishui River,Southwest China.The results showed clearly that the geochemistry of metal elements was largely controlled by the hydrodynamic eff ect,of which the diff erent flowrates introduce a natural sorting of diff erent mineral particles transported at diff erent flood stages,depending on their shape,size and density.The maximum concentrations of alkaline and alkaline earth metals(Li,Mg,K,Rb and Sr)in SPM appeared before the flood peak,which was largely controlled by aluminosilicate minerals.However,transition metals(Cr,Mn,Fe,Ni and Cu)showed their abundance peaks lagging behind the flowrate summit,as a result of the late arrival of coarse particles or heavy minerals,evidenced by the mineralogical phase analysis.In addition,the distribution coe fficient(K_(d))between particulate and dissolved loads were lower and stable for soluble alkali/alkaline earth metals which could be aff ected by pH,while higher and fluctuant for transition metals that were largely influenced by SPM content.Overall,the present study reveals clear eff ects of hydrodynamic sorting on the geochemistry of metal elements during the flood event of the natural Chishui River,which should be taken into account when characterizing the riverine flux and their impact on marine ecosystem.
文摘Agricultural intensification has led to an increase in monoculture and the use of chemical pesticides,resulting in a decline in biodiversity and a reduction in ecosystem services,particularly biological pest management.However,studies have shown that agroforestry can not only improve land productivity and biodiversity but also regulate some ecosystem services.This study reviews the impacts of physical and biological factors on herbivorous pests,parasites,and predatory natural enemies in fruit-crop agroforestry systems.Fruit-crop agroforestry systems provide high spatial heterogeneity by altering crop layouts,regulating the microclimate and soil quality,and offering food resources and shelter for natural enemies,thus promoting biological pest control.This enhances biological control and makes the agrocomplex system an effective tool for sustainable agriculture.Our research shows that volatile plant substances attract or repel pests and natural enemies based on the characteristics of the insects themselves.When scientifically designed,fruit-crop agroforestry systems provide high spatial heterogeneity and favorable microclimatic conditions,which enhance biological pest control and make the agroforestry system an effective tool for sustainable agriculture.Our research shows that fruit-crop agroforestry systems can provide richer food resources and habitat,enhancing biological pest control and improving pest management.
文摘With growing concerns for global warming and environmental issues,the research community has contributed significantly to green technology in the area of material science through the development of natural fiber-reinforced polymer composites(NFRPC).Polymers serve as the matrix in NFRPC,while natural fibers serve as the reinforcing materials.Demand for high-performing materials made with natural resources is growing continuously.Natural fiber-reinforced polymer composites are sustainable biocomposites fabricated with natural fibers embedded with a polymer matrix.They offer a wide range of advantages,including a low weight-to-strength ratio,high flexural strength,damping properties,and resistance to corrosion,wear,and impact.Understanding the basic properties,characteristics,and processing techniques for natural fibers is important to consider their use as raw materials for high-quality biocomposite.Natural fibers come with low density and a high strengthto-weight ratio,allowing them to be a potential reinforcement for low-weight composites.This article attempts to present a comprehensive review of the available natural fibers,their classification,types,structures,physical properties,characteristics,and mechanical properties.Natural fibers are hydrophilic in nature and require physical and chemical treatment prior to their application as reinforcing material.This review will also cover the required physical and chemical treatments of natural fibers for fabricating biocomposites.
基金supported by the National Natural Science Foundation of China(grant number 22309103)Natural Science Foundation of Shandong Province(grant numbers ZR2022MH162,ZR2022QE202)+1 种基金PhD Research Start-up Foundation of Qufu Normal University(grant numbers 614901,615201)the project of introduction and cultivation for young innovation talents in the colleges and universities of Shandong Province(grant number 614202).
文摘Tumors,due to their diversity and heterogeneity,pose a significant threat to human health.Multidrug resistance is a prevalent and grave issue in clinical treatment,resulting in treatment failure and cancer recurrence.This resistance renders conventional drug therapies ineffective,presenting a substantial challenge to human health and medical care.Exploring natural products as potential sources for anti-cancer drugs could lead to the development of innovative and efficacious cancer treatments.This article aims to investigate the health implications of natural products(such as paclitaxel,podophyllotoxin,homoharringtonine,camptothecin,and vinblastine)in the discovery of anti-cancer drugs while discussing the methods and progress made in researching novel anti-cancer drugs derived from natural products.The paper discusses the diversity,intricate structures,and target affinity of natural products along with their structural modification techniques,combination therapies utilization possibilities with prodrugs or nanoparticles.Additionally,considering the escalating multidrug resistance observed in tumors nowadays;certain natural products offer new insights and approaches for discovering effective anti-tumor drugs that are crucial for addressing global public health challenges.The challenges faced by natural products during drug development including issues related to bioavailability toxicity concerns as well as limited resources are examined thoroughly.Potential opportunities current issues along with future challenges are highlighted aiming at facilitating the clinical translation of original anti-cancer drugs using natural products.
基金financial support from the National Natural Science Foundation of China(Grant No.41941018).
文摘The impacts of natural boulders carried by debris flows pose serious risks to the safety and reliability of structures and buildings.Natural boulders can be highly random and unpredictable.Consequently,boulder control during debris flows is crucial but difficult.Herein,an eco-friendly control system featuring anchoring natural boulders(NBs)with(negative Poisson's ratio)NPR anchor cables is proposed to form an NB-NPR baffle.A series of flume experiments are conducted to verify the effect of NB-NPR baffles on controlling debris flow impact.The deployment of NB-NPR baffles substantially influences the kinematic behavior of a debris flow,primarily in the form of changes in the depositional properties and impact intensities.The results show that the NB-NPR baffle matrix successfully controls boulder mobility and exhibits positive feedback on solid particle deposition.The NB-NPR baffle group exhibits a reduction in peak impact force ranging from 29%to 79%compared to that of the control group in the basic experiment.The NPR anchor cables play a significant role in the NB-NPR baffle by demonstrating particular characteristics,including consistent resistance,large deformation,and substantial energy absorption.The NB-NPR baffle innovatively utilizes the natural boulders in a debris flow gully by converting destructive boulders into constructive boulders.Overall,this research serves as a basis for future field experiments and applications.
基金funded by the National Natural Science Foundation of China(No.82204250)the China Postdoctoral Science Foundation(No.2021M693961)+3 种基金the Young and Middle-Aged Talent Project of the Hubei Provincial Department of Education(No.Q20222808)High-level Talent Research Initiation Fund Project of Hunan University of Chinese Medicine(No.0004010)Hubei University of Science and Technology Special Scientific Research Fund of Medical School of Ophthalmology and Otorhinolaryngology(No.2020WG13)Henan Provincial Science and Technology Development Program Project(No.212102310346).
文摘Background:Cardiovascular and cerebrovascular diseases are significant health threats that have been found to involve ferroptosis in related cells.This study aims to comprehensively examine the role and mechanism of natural products,derived from traditional Chinese herbal medicines,in intervening in ferroptosis from the perspective of cardiovascular and cerebrovascular aspects.Methods:A literature survey was conducted using Scopus,Pubmed,Reaxys,and Google Scholar databases to review studies on natural products(such as baicalin,puerarin,and ginsenosides)derived from herbs like scutellaria baicalensis,pueraria lobata,ginseng,panax quinquefolium,and panax notoginseng.The focus was on their potential as drugs for the treatment of cardiovascular and cerebrovascular diseases,particularly their ability to inhibit ferroptosis.Results:The review revealed that various natural products exhibit disease protection and prevention properties,inhibiting ferroptosis through diverse pathways and targets in cardiovascular and cerebrovascular diseases.The involvement of these natural products in key pathways associated with ferroptosis,including amino acid metabolism,iron metabolism,and lipid peroxidation,was elucidated.Notably,tanshinone IIA,resveratrol,astragaioside IV,and vitexin were found to regulate ferroptosis in both cardiovascular and cerebrovascular cells.Additionally,the impact of these natural products on key targets of ferroptosis,such as SLC7A11,DMTI,TfRI,Nrf2,HO-1,GPX4,NCOA4,and LOX,was discussed.Conclusion:This study provides a comprehensive understanding of the role and mechanism of natural products in intervening in ferroptosis related to cardiovascular and cerebrovascular diseases.The findings pave the way for potential future treatments targeting ferroptosis in these diseases.
基金supported by funding from the Wuhan Technology and Business University Doctoral Research Fund Project[Grant No.D2024007].
文摘Economic growth affects natural resources and the environment directly and indirectly;however,the exact role that natural resources play in environmental sustainability remains unknown.This paper revisits the relationship between natural resources and CO_(2)emissions by considering the role of green finance vis-à-vis the aggregated and disaggregated analysis.Empirical panel data estimation analyzes a sample of emerging countries over the 2001-2019 period using the recently developed econometric cross-sectional auto-regressive distributed lag(CS-ARDL)technique.The findings show that natural resource components(natural gas,mineral rent,oil rent,and coal rent)are negatively associated with environmental pollution.In contrast,overall natural resource consumption helps reduce carbon emissions.However,we find that green finance contributes to carbon emission reduction.In contrast,education causes pollution by contributing to carbon emissions.We offer policy recommendations about the effectiveness of green financing for the sustainable use of natural resources in diminishing pollution.
基金Supported by the 2023 Government Funded Project of the Outstanding Talents Training Program in Clinical Medicine,No.ZF2023165Key Research and Development Projects of Hebei Province,No.18277731DNatural Science Foundation of Hebei Province,No.H202423105.
文摘In the contemporary medical landscape,the burgeoning interest in natural therapies,particularly for managing gastrointestinal disorders,has brought traditional Chinese medicine(TCM)to the forefront.This article explains the core principles and clinical applications of TCM in treating these conditions,furthering the discourse through an examination of integrated TCM strategies,as demonstrated in the study by Zhou et al.While TCM has shown promising clinical outcomes,it encounters significant hurdles in standardization,mechanistic research,and clinical validation.Future investigations should aim to solidify the scientific underpinnings of TCM and expand its use in gastrointestinal disease management,striving for a seamless fusion of traditional and contemporary medical practices.
文摘The attenuation of the acoustic activity in marble specimens under uniaxial compressive loadingunloading loops is quantified in juxtaposition to that of the electric activity.In parallel,the existence of"pre-failure indiceso"warning about entrance into a critical stage,that of impending fracture,is explored.The acoustic activity is quantified in terms of the normalized number of acoustic hits,their average rate of production and their cumulative energy,and,the cumulative counts and their average rate of change.The electric activity is studied in terms of the pressure stimulated currents and the electric charge released.The analysis revealed that the acoustic and electric activities are linearly correlated to each other,suggesting that they are different manifestations of the same damage mechanisms.In addition,Kaiser's effect,governing the acoustic activity,is found to govern,also,the electric activity.Moreover,it is concluded that entrance into the critical stage is safely predicted by means of a simple criterion,based on the evolution of the average rate of change of the normalized cumulative counts in the natural time domain.These predictions are almost identical with those of the criterion based on the "varianceo" and the "entropies" of the time series of acoustic events in this domain.
基金This study was supported by the Foundation of National Engineering Laboratory for Exploration and Development of Low-Permeability Oil and Gas Fields(2023-015).
文摘Hydraulic fracturing is a crucial technique for efficient development of coal reservoirs.Coal rocks typically contain a high density of natural fractures,which serve as conduits for fracturing fluid.Upon injection,the fluid infiltrates these natural fractures and leaks out,resulting in complex fracture morphology.The prediction of hydraulic fracture network propagation for coal reservoirs has important practical significance for evaluating hydraulic fracturing.This study proposes a novel inversion method for predicting fracture networks in coal reservoirs,explicitly considering the distribution of natural fractures.The method incorporates three distinct natural fracture opening modes and employs a fractal probability function to constrain fracture propagationmorphology.Based on thismethod,the study compares hydraulic fracture networkmorphologies in coal reservoirs with andwithout the presence of natural fractures.Theresults showthatwhile both reservoir types exhibitmulti-branch fracture networks,reservoirs containing natural fractures demonstrate greater branching and a larger stimulated reservoir volume(SRV).Additionally,the study employs a fractal dimension calculation method to quantitatively describe the geometric distribution characteristics of fractures.The analysis reveals that the geometry and distribution of natural fractures,as well as reservoir geological parameters,significantly influence the fracture networkmorphology and fractal dimension.The contact angle between natural and hydraulic fractures affects propagation direction;specifically,when the contact angle isπ/2,the fractal dimension of the hydraulic fracture network is maximized.Moreover,smaller lengths and spacings of natural fracture led to higher fractal dimensions,which can significantly increase the SRV.The proposed method offers an effective tool for evaluating the hydraulic fracturing of coal reservoirs.
基金financially supported by National Science and Technology Major Projects(Grant Nos.2016ZX05050,2017ZX05001002-008)CNPC Major Projects(Grant No.2021DJ2203)The Open Fund by the State Key Laboratory of Continental Dynamics,Northwest University and the Key Laboratory for Digital Land and Resources of Jiangxi Province(Grant No.DLLJ202017)。
文摘The formation of Mesozoic natural gas in the Pengyang area of southwestern Ordos Basin is discussed,from the perspective of microbial community characteristics,in order to clarify the relationship between the origin of natural gas and its associated indigenous microbial community.The types and diversity of indigenous microbial communities associated with the oil reservoir were studied by means of collecting reservoir formation water samples from exploration wells.The indigenous microbial communities in the Chang 8 member of the Yanchang Formation were primarily distributed within Proteobacteria and Firmicutes,including the specific species and genera of Methylobacter,Pseudomonas,Haibacter,Toxobacillus,Acinetobacter and Adura actinomyces.The results of diversity analysis shows that the number of common genes was 5448,while the number of unique genes and information was less.This reflects the fact that the strata in the study area are relatively closed and not invaded by external water sources,which leads to the development of biological community diversity.In conjunction with the analysis of geochemical characteristics of oil and gas reservoirs in this area,this indicates that the study area possesses the necessary geological conditions for microbial degradation.It is the first time that the species and diversity of the indigenous microbial community in the Ordos Basin have been analyzed,showing that microbial degradation is the main cause of natural gas formation here,changes the characteristics of crude oil in this area and provides first-hand information on the impact of indigenous microorganisms on the reservoir.
文摘Any new report on the anticancer properties of natural products always awakens new satisfaction and hope about the role of the international scientific community in its continuous contributions to human health,particularly when those reports contribute to both the understanding and therapeutics of cancer.For many de-cades,natural products have been pivotal in drug discovery programs because they offer a diverse array of anticancer therapeutic possibilities.Recently,two manuscripts published in the World Journal of Gastrointestinal Oncology added new data to the already extensive body of anticancer preclinical evidence for resvera-trol and senegenin,two compounds widely present in herbal preparations used in traditional Chinese medicine.The first one,with comprehensive and recognized anticancer properties,and the second one,shows a compelling body of evidence supporting its neuroprotective effects,but with emerging anticancer activities.Natural products have become key elements in the expanding and dynamic field of anticancer drug discovery.However,urgent and collective efforts are still needed to bridge the gap between preclinical and clinical research and thus bring new anticancer therapeutic breakthroughs.
基金Supported by the National Natural Science Foundation of China(No.51909154)Shanghai Engineering Research Center of Ship Intelligent Maintenance and Energy Efficiency(No.20DZ2252300).
文摘Using natural gas(NG)as the primary fuel helps alleviate the fossil fuel crisis while reducing engine soot and nitrogen oxide(NO_(X))emissions.In this paper,the influences of a novel split injection concept on an NG high pressure direct injection(HPDI)engine are examined.Four typical split injection strategies,namely split pre-injection of pilot diesel(PD)and NG,split post-injection of PD and NG,split pre-injection of NG,and split post-injection of PD,were developed to investigate the influences on combustion and emissions.Results revealed that split pre injection of NG enhanced the atomization of PD,whereas the split post-injection of NG lowered the temperature in the core region of the PD spray,resulting in the deterioration of combustion.The effect of the split injection strategy on indicated thermal efficiency exceeded 7.5%.Split pre-injection was favorable to enhancing thermal efficiency,whereas split post-injection was not.Ignition delay,combustion duration,and premixed combustion time proportion were affected by injection strategies by 3.8%,50%,and 19.7%,respectively.Split pre-injection increased CH_(4) emission in the exhaust.Split post-injection,especially split post-injection of PD and NG,reduced the unburned CH_(4) emission by approximately 30%.When the split post-injection ratio was less than 30%,the trade-off between NO_(X) and soot was interrupted.The distribution range of hydroxyl radicals was expanded by pre-injection,and NO_(X) was generated in the region where the NG jet hit the wall.This paper provides valuable insights into the optimization of HPDI injection parameters.
基金This work was supported by the Ministry of Industry and Information Technology High Tech Ship Special Project(Grant No.CBG3N21-2-6).
文摘Extracted natural gas hydrate is a multi-phase and multi-component mixture,and its complex composition poses significant challenges for transmission and transportation,including phase changes following extraction and sediment deposition within the pipeline.This study examines the flow and heat transfer characteristics of hydrates in a riser,focusing on the multi-phase flow behavior of natural gas hydrate in the development riser.Additionally,the effects of hydrate flow and seawater temperature on heat exchange are analyzed by simulating the ambient temperature conditions of the South China Sea.The findings reveal that the increase in unit pressure drop is primarily attributed to higher flowvelocities,which result in increased friction of the hydrate flowwithin the development riser.For example,at a hydrate volume fraction of 10%,the unit pressure drop rises by 166.65%and 270.81% when the average inlet velocity is increased from1.0 to 3.0m/s(a two-fold increase)and 5.0 m/s(a four-fold increase),respectively.Furthermore,the riser outlet temperature rises with increasing hydrate flowrates.Under specific heat loss conditions,the flowratemust exceed a minimum threshold to ensure safe transportation.The study also indicates that the riser outlet temperature increases with higher seawater temperatures.Within the seawater temperature range of 5℃ to 15℃,the heat transfer efficiency is reduced compared to the range of 15℃ to 20℃.This discrepancy is due to the fact that as the seawater temperature rises,the convective heat transfer coefficient between the hydrate and the inner wall of the riser also increases,leading to improved overall heat transfer between the hydrate and the pipeline.
文摘The emergence of adversarial examples has revealed the inadequacies in the robustness of image classification models based on Convolutional Neural Networks (CNNs). Particularly in recent years, the discovery of natural adversarial examples has posed significant challenges, as traditional defense methods against adversarial attacks have proven to be largely ineffective against these natural adversarial examples. This paper explores defenses against these natural adversarial examples from three perspectives: adversarial examples, model architecture, and dataset. First, it employs Class Activation Mapping (CAM) to visualize how models classify natural adversarial examples, identifying several typical attack patterns. Next, various common CNN models are analyzed to evaluate their susceptibility to these attacks, revealing that different architectures exhibit varying defensive capabilities. The study finds that as the depth of a network increases, its defenses against natural adversarial examples strengthen. Lastly, Finally, the impact of dataset class distribution on the defense capability of models is examined, focusing on two aspects: the number of classes in the training set and the number of predicted classes. This study investigates how these factors influence the model’s ability to defend against natural adversarial examples. Results indicate that reducing the number of training classes enhances the model’s defense against natural adversarial examples. Additionally, under a fixed number of training classes, some CNN models show an optimal range of predicted classes for achieving the best defense performance against these adversarial examples.
基金Sponsored by the National Natural Science Foundation of China:Visual Perception Based Natural Intervention for Patients in HSCT Wards(52278045)Innovation and Entrepreneurship Training Programme for Students in 2024(10805136024XN139-91).
文摘In this study,the evidence-based design(EBD)of naturalized decoration in hematopoietic stem cell transplantation(HSCT)wards of Peking University First Hospital was explored to improve patients’psychological state and rehabilitation environment by introducing natural elements.Based on questionnaire surveys and literature research,the EBD method was adopted to propose a naturalized decoration scheme for HSCT wards,and a satisfaction evaluation was conducted after construction and use.The research results show that naturalized decoration can effectively enhance the satisfaction and comfort of patients and medical staff,verifying its positive effects in HSCT wards.
文摘Rural education in China faces significant challenges,including limited resources,declining student enrollment,and frequent school closures.This paper examines the educational leadership and management strategies employed by Simin Primary School,a century-old rural institution in Zhuji City,which has successfully revitalized its community and attracted students through the innovative practice of nature education.By leveraging local cultural and environmental resources,the school has established a sustainable model for small rural schools.
