期刊文献+
共找到7,047篇文章
< 1 2 250 >
每页显示 20 50 100
THE NEW ENVIRONMENTALISM OF THE FUTURE FASHION SECTOR
1
《China's Foreign Trade》 2018年第6期63-63,共1页
Currently,the fashion sector has entered the“industrial restructuring”stage,and“green sustainability”and“capital concentration”have become new important concepts in fashion.These two elements are also the key to... Currently,the fashion sector has entered the“industrial restructuring”stage,and“green sustainability”and“capital concentration”have become new important concepts in fashion.These two elements are also the key to understand the industrial reform ofthe fashion sector.Therefore,under the backdrop that the global fashion sector is thriving,the“Beijing Fashion Forum-Shape New Pattern of the Fashion Sector”was held in Beijing to discuss how to effectively integrate sustainable design with traditional manufacturing model and how to expand the business landscape of the textile and garment sector by virtue of the capital power and bring a new growth drive to the sector. 展开更多
关键词 THE NEW environmentalism OF THE FUTURE FASHION SECTOR
下载PDF
The impact of demographic dynamics on food consumption and its environmental outcomes:Evidence from China 被引量:2
2
作者 Shaoting Li Xuan Chen +1 位作者 Yanjun Ren Thomas Glauben 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第2期414-429,共16页
With increasing population and changing demographics,food consumption has experienced a significant transition in quantity and quality.However,a dearth of knowledge remains regarding its environmental impacts and how ... With increasing population and changing demographics,food consumption has experienced a significant transition in quantity and quality.However,a dearth of knowledge remains regarding its environmental impacts and how it responds to demographic dynamics,particularly in emerging economies like China.Using the two-stage Quadratic Almost Demand System(QUAIDS)model,this study empirically examines the impact of demographic dynamics on food consumption and its environmental outcomes based on the provincial data from 2000 to 2020 in China.Under various scenarios,according to changes in demographics,we extend our analysis to project the long-term trend of food consumption and its environmental impacts,including greenhouse gas(GHG)emissions,water footprint(WF),and land appropriation(LA).The results reveal that an increase in the proportion of senior people significantly decreases the consumption of grain and livestock meat and increases the consumption of poultry,egg,and aquatic products,particularly for urban residents.Moreover,an increase in the proportion of males in the population leads to higher consumption of poultry and aquatic products.Correspondingly,in the current scenario of an increased aging population and sex ratio,it is anticipated that GHG emissions,WF,and LA are likely to decrease by 1.37,2.52,and 3.56%,respectively.More importantly,in the scenario adhering to the standards of nutritional intake according to the Dietary Guidelines for Chinese Residents in 2022,GHG emissions,WF,and LA in urban areas would increase by 12.78,20.94,and 18.32%,respectively.Our findings suggest that changing demographics should be considered when designing policies to mitigate the diet-environment-health trilemma and achieve sustainable food consumption. 展开更多
关键词 demographic dynamics food consumption environmental impacts nutrition intakes
下载PDF
Effects of thinning on the understory light environment of different stands and the photosynthetic performance and growth of the reforestation species Phoebe bournei 被引量:1
3
作者 Shicheng Su Nianqing Jin Xiaoli Wei 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第1期12-28,共17页
Light levels determine regeneration in stands and a key concern is how to regulate the light environment of different stand types to the requirements of the understory.In this study,we selected three stands typical in... Light levels determine regeneration in stands and a key concern is how to regulate the light environment of different stand types to the requirements of the understory.In this study,we selected three stands typical in south China(a Cryptomeria japonica plantation,a Quercus acutissima plantation,and a mixed stand of both)and three thinning intensities to determine the best understory light environ-ment for 3-year-old Phoebe bournei seedlings.The canopy structure,understory light environment,and photosynthe-sis and growth indicators were assessed following thin-ning.Thinning improved canopy structure and understory light availability of each stand;species composition was the reason for differences in the understory light environ-ment.Under the same thinning intensity,the mixed stand had the greatest light radiation and most balanced spectral composition.P.bournei photosynthesis and growth were closely related to the light environment;all three stands required heavy thinning to create an effective and sustained understory light environment.In a suitable understory light environment,the efficiency of light interception,absorption,and use by seedlings was enhanced,resulting in a higher carbon assimilation the main limiting factor was stomatal conductance.As a shade-avoidance signal,red/far-red radia-tion is a critical factor driving changes in photosynthesis and growth of P.bournei seedlings,and a reduction increased light absorption and use capacity and height:diameter ratios.The growth advantage transformed from diameter to height,enabling seedlings to access more light.Our findings suggest that the regeneration of shade-tolerant species such as P.bournei could be enhanced if a targeted approach to thinning based on stand type was adopted. 展开更多
关键词 THINNING Understory light environment Phoebe bournei Photosynthetic performance Growth performance
下载PDF
Recent Progress in Reinforcement Learning and Adaptive Dynamic Programming for Advanced Control Applications 被引量:1
4
作者 Ding Wang Ning Gao +2 位作者 Derong Liu Jinna Li Frank L.Lewis 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第1期18-36,共19页
Reinforcement learning(RL) has roots in dynamic programming and it is called adaptive/approximate dynamic programming(ADP) within the control community. This paper reviews recent developments in ADP along with RL and ... Reinforcement learning(RL) has roots in dynamic programming and it is called adaptive/approximate dynamic programming(ADP) within the control community. This paper reviews recent developments in ADP along with RL and its applications to various advanced control fields. First, the background of the development of ADP is described, emphasizing the significance of regulation and tracking control problems. Some effective offline and online algorithms for ADP/adaptive critic control are displayed, where the main results towards discrete-time systems and continuous-time systems are surveyed, respectively.Then, the research progress on adaptive critic control based on the event-triggered framework and under uncertain environment is discussed, respectively, where event-based design, robust stabilization, and game design are reviewed. Moreover, the extensions of ADP for addressing control problems under complex environment attract enormous attention. The ADP architecture is revisited under the perspective of data-driven and RL frameworks,showing how they promote ADP formulation significantly.Finally, several typical control applications with respect to RL and ADP are summarized, particularly in the fields of wastewater treatment processes and power systems, followed by some general prospects for future research. Overall, the comprehensive survey on ADP and RL for advanced control applications has d emonstrated its remarkable potential within the artificial intelligence era. In addition, it also plays a vital role in promoting environmental protection and industrial intelligence. 展开更多
关键词 Adaptive dynamic programming(ADP) advanced control complex environment data-driven control event-triggered design intelligent control neural networks nonlinear systems optimal control reinforcement learning(RL)
下载PDF
Recent Developments in Metallic Degradable Micromotors for Biomedical and Environmental Remediation Applications
5
作者 Sourav Dutta Seungmin Noh +4 位作者 Roger Sanchis Gual Xiangzhong Chen Salvador Pané Bradley J.Nelson Hongsoo Choi 《Nano-Micro Letters》 SCIE EI CSCD 2024年第3期1-35,共35页
Synthetic micromotor has gained substantial attention in biomedicine and environmental remediation.Metal-based degradable micromotor composed of magnesium(Mg),zinc(Zn),and iron(Fe)have promise due to their nontoxic fu... Synthetic micromotor has gained substantial attention in biomedicine and environmental remediation.Metal-based degradable micromotor composed of magnesium(Mg),zinc(Zn),and iron(Fe)have promise due to their nontoxic fuel-free propulsion,favorable biocompatibility,and safe excretion of degradation products Recent advances in degradable metallic micromotor have shown their fast movement in complex biological media,efficient cargo delivery and favorable biocompatibility.A noteworthy number of degradable metal-based micromotors employ bubble propulsion,utilizing water as fuel to generate hydrogen bubbles.This novel feature has projected degradable metallic micromotors for active in vivo drug delivery applications.In addition,understanding the degradation mechanism of these micromotors is also a key parameter for their design and performance.Its propulsion efficiency and life span govern the overall performance of a degradable metallic micromotor.Here we review the design and recent advancements of metallic degradable micromotors.Furthermore,we describe the controlled degradation,efficient in vivo drug delivery,and built-in acid neutralization capabilities of degradable micromotors with versatile biomedical applications.Moreover,we discuss micromotors’efficacy in detecting and destroying environmental pollutants.Finally,we address the limitations and future research directions of degradable metallic micromotors. 展开更多
关键词 Magnesium Zinc Iron Biodegradable microrobot BIOMEDICAL Environmental
下载PDF
Integrated biomarker response to assess toxic impacts of iron and manganese on deep-sea mussel Gigantidas platifrons under a deep-sea mining activity scenario
6
作者 Li ZHOU Mengna LI +7 位作者 Zhaoshan ZHONG Minxiao WANG Hao CHEN Chao LIAN Hao WANG Huan ZHANG Lei CAO Chaolun LI 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第2期522-532,共11页
Deep-sea mining activities can potentially release metals,which pose a toxicological threat to deep-sea ecosystems.Nevertheless,due to the remoteness and inaccessibility of the deep-sea biosphere,there is insufficient... Deep-sea mining activities can potentially release metals,which pose a toxicological threat to deep-sea ecosystems.Nevertheless,due to the remoteness and inaccessibility of the deep-sea biosphere,there is insufficient knowledge about the impact of metal exposure on its inhabitants.In this study,deep-sea mussel Gigantidas platifrons,a commonly used deep-sea toxicology model organism,was exposed to manganese(100,1000μg/L)or iron(500,5000μg/L)for 7 d,respectively.Manganese and iron were chosen for their high levels of occurrence within deep-sea deposits.Metal accumulation and a battery of biochemical biomarkers related to antioxidative stress in superoxide dismutase(SOD),catalase(CAT),malondialdehyde(MDA);immune function in alkaline phosphatase(AKP),acid phosphatase(ACP);and energy metabolism in pyruvate kinase(PK)and hexokinase(HK)were assessed in mussel gills.Results showed that deep-sea mussel G.platifrons exhibited a high capacity to accumulate Mn/Fe.In addition,most tested biochemical parameters were altered by metal exposure,demonstrating that metals could induce oxidative stress,suppress the immune system,and affect energy metabolism of deep-sea mussels.The integrated biomarker response(IBR)approach indicated that the exposure to Mn/Fe had a negative impact on deep-sea mussels,and Mn demonstrated a more harmful impact on deep-sea mussels than Fe.Additionally,SOD and CAT biomarkers had the greatest impact on IBR values in Mn treatments,while ACP and HK were most influential for the low-and high-dose Fe groups,respectively.This study represents the first application of the IBR approach to evaluate the toxicity of metals on deep-sea fauna and serves as a crucial framework for risk assessment of deep-sea mining-associated metal exposure. 展开更多
关键词 MUSSEL metal deep-sea mining BIOMARKER environmental monitoring
下载PDF
Review on inorganic and polymeric materials-coordinated metal-organic-framework photocatalysts for green hydrogen evolution
7
作者 Dong-Eun Lee Mohtaram Danish +1 位作者 Umair Alam Wan-Kuen Jo 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第5期322-356,共35页
Metal-organic frameworks(MOFs)possess a distinct advantage over conventional heterogeneous photocatalysts because of their carefully defined architecture and particular pores,which facilitate the targeted incorporatio... Metal-organic frameworks(MOFs)possess a distinct advantage over conventional heterogeneous photocatalysts because of their carefully defined architecture and particular pores,which facilitate the targeted incorporation of other efficient cocatalysts or semiconductor materials.The integration of MOFs with other materials has resulted in significant breakthroughs,as the coupled materials improve the performance due to the combined effect.The unique MOF structures allow them to host foreign materials,which results in harvesting the visible region of the solar spectrum and effectively mitigating charge recombination by promoting charge separation.The review presents an evaluation of the latest developments in the utilization of surface and/or pore chemistry of MOF-supported heterojunctions for photocatalytic green-hydrogen generation with a basic understanding of the mechanism involved.The review begins with the basic principles of photocatalysis,the significance of MOFs,their optical properties,the methods used for synthesizing MOFs,and their coordination with other inorganic and polymeric materials.Furthermore,methods to increase photocatalytic H2 evolution using MOF-supported heterojunction have been proposed as standard practice.Lastly,to address environmental challenges,we highlight the future potential of MOF-supported heterojunctions for use in green-energy production.We hope that this review provides guidance to researchers in the development of effective heterojunctions based on MOFs to address challenges in energy applications and catalytic processes. 展开更多
关键词 Renewable energy Environmental challenge HETEROJUNCTION Water splitting PHOTOCATALYSIS
下载PDF
Synthesis and nitrogen content regulation of diamond in a high-pressure hydrogen-rich environment
8
作者 黄国锋 陈良超 房超 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期541-546,共6页
The regulating nitrogen content of diamond in a hydrogen-rich high-temperature and high-pressure(HPHT) growth environment was systematically investigated in this work by developing three growth systems,namely, "F... The regulating nitrogen content of diamond in a hydrogen-rich high-temperature and high-pressure(HPHT) growth environment was systematically investigated in this work by developing three growth systems,namely, "FeNi+Ti", "FeNi+G_(3)N_(6)H_(6)",and "FeNi+Ti+C_(3)N_(6)H_(6)".Optical microscopy,infrared spectroscopy,and photoluminescence(PL)spectroscopy measurements were conducted to analyze the spectroscopic characteristics of diamonds grown in these three systems.From our analysis,it was demonstrated that the presence of hydrogen in the sp^(3) hybrid C-H does not directly affect the color of the diamond and facilitates the increase of the nitrogen-vacancy(NV) center concentration in a highnitrogen-content diamond.In addition,titanium plays an important role in nitrogen removal,while its impact on hydrogen doping within the diamond lattice is insignificant.Most importantly,by regulating the ratio of nitrogen impurities that coexist in the nitrogen and hydrogen HPHT environment,the production of hydrogenous Ⅱa-type diamond,hydrogenous Ib-type diamond,and hydrogenous high-nitrogen-type diamonds was achieved with a nitrogen content of less than 1 ppm to 1600 ppm. 展开更多
关键词 DIAMOND HPHT superhard material hydrogen-rich environment
下载PDF
The Variation of Plankton Community Structure in Artificial Reef Area and Adjacent Waters in Haizhou Bay
9
作者 GAO Shike SHI Yixi +1 位作者 LU Yanan ZHANG Shuo 《Journal of Ocean University of China》 CAS CSCD 2024年第1期264-276,共13页
Plankton are an important component of marine protected areas(MPAs),and its communities would require much smaller interpatch distances to ensure connection among MPAs.According to the survey from MPAs dominated by ar... Plankton are an important component of marine protected areas(MPAs),and its communities would require much smaller interpatch distances to ensure connection among MPAs.According to the survey from MPAs dominated by artificial reefs and adjacent waters(estuary area(EA),aquaculture area(AA),artificial reef area(ARA),natural area(NA)and comprehensive effect area(CEA))in Haizhou Bay in spring and autumn,we analyzed phyto-zooplankton composition,abundance and biomass,and correlation with hydrologic variables to gain information about the forces that structure the plankton.The results showed that the dominant zooplankton were copepods(spring,98.9%;autumn,94.2%),while the phytoplankton were mainly composed of Bacillariophyta(spring,61.8%;autumn,95.6%).The RDA results showed that temperature,salinity and depth highly associated with the distribution and composition of plankton species among the habitats than other factors in spring;temperature,Chla and DO had the strongest influence in autumn.The zooplankton in the ARA and AA ecosystems basically contained the same species as those in other habitats,and each habitat also exhibited a relatively unique combination of plankton species.The structures of the EA zooplankton in spring and the EA phytoplankton in both seasons were much different than other habitats,which may have been caused by factors such as currents and tides.We concluded that there exists similarity of the plankton community between artificial reef area and adjacent waters,whereas the EAs may be relatively independent systems.Therefore,these interaction between plankton community should be considered when designing MPA networks,and ocean circulations should be considered more than the environmental factors. 展开更多
关键词 ZOOPLANKTON PHYTOPLANKTON seasonal variation environmental factor artificial reef
下载PDF
THE PERSISTENCE OF SOLUTIONS IN A NONLOCAL PREDATOR-PREY SYSTEM WITH A SHIFTING
10
作者 赵敏 袁荣 《Acta Mathematica Scientia》 SCIE CSCD 2024年第3期1096-1114,共19页
In this paper,we mainly study the propagation properties of a nonlocal dispersal predator-prey system in a shifting environment.It is known that Choi et al.[J Differ Equ,2021,302:807-853]studied the persistence or ext... In this paper,we mainly study the propagation properties of a nonlocal dispersal predator-prey system in a shifting environment.It is known that Choi et al.[J Differ Equ,2021,302:807-853]studied the persistence or extinction of the prey and of the predator separately in various moving frames.In particular,they achieved a complete picture in the local diffusion case.However,the question of the persistence of the prey and of the predator in some intermediate moving frames in the nonlocal diffusion case was left open in Choi et al.'s paper.By using some a prior estimates,the Arzelà-Ascoli theorem and a diagonal extraction process,we can extend and improve the main results of Choi et al.to achieve a complete picture in the nonlocal diffusion case. 展开更多
关键词 predator-prey system PERSISTENCE nonlocal dispersal shifting environment
下载PDF
Sedimentary Environment and Mineralization of the Black Shale Polymetallic Layer in the Early Cambrian,SW China:Constraints from in situ LA-ICP-MS Analysis of Pyrite
11
作者 YANG Zhen FU Yong +2 位作者 LI Chao CAI Xi GUO Chuan 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第2期416-429,共14页
A polymetallic layer is usually developed at the bottom of the early Cambrian black shale in Guizhou Province.The mineral that makes up the polymetallic layer is related to the sedimentary facies.To analyze the differ... A polymetallic layer is usually developed at the bottom of the early Cambrian black shale in Guizhou Province.The mineral that makes up the polymetallic layer is related to the sedimentary facies.To analyze the differentiation mechanism between polymetallic deposits(Ni-Mo and V),the Zhijin Gezhongwu profile located in the outer shelf and the Sansui Haishan V deposit located in the lower slope are selected to study the in situ sulfur isotopes and trace elements of pyrite.The results show that δ^(34)S values of pyrite vary widely from−7.8‰to 28‰in the Gezhongwu profile,while the δ^(34)S values are relatively uniform(from 27.8‰to 38.4‰)in the Haishan profile.The isotopic S composition is consistent with the transition that occurs in the sedimentary phase from the shelf to the deep sea on the transgressive Yangtze platform;this indicates that the δ^(34)SO_(4)^(2−)values in seawater must be differently distributed in depositional environments.The sulfur in the Ni-Mo layer is produced after the mixing of seawater and hydrothermal fluid,while the V layer mainly originates from seawater.Overall,the Ni-Mo and V deposits have been differentiated primarily on the basis of the combined effect of continental weathering and hydrothermal fluid. 展开更多
关键词 sedimentary environment black shale polymetallic layer PYRITE early Cambrian
下载PDF
Does the provision of live black soldier fly and yellow mealworm larvae improve Muscovy duck welfare?
12
作者 Marta Gariglio Sihem Dabbou +8 位作者 Manuela Renna Ilaria Biasato Sara Bellezza Oddon Marco Meneguz Raul Daniel Miazzo Stefania Bergagna Elena Colombino Elisabetta Macchi Achille Schiavone 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2024年第1期442-455,共14页
Background The provision of environmental enrichments to Muscovy ducks could reduce the expression of the aggressive behaviors.The aim of the present study was to evaluate the effects of black soldier fly(BSF)and yell... Background The provision of environmental enrichments to Muscovy ducks could reduce the expression of the aggressive behaviors.The aim of the present study was to evaluate the effects of black soldier fly(BSF)and yellow mealworm(YM)live larva provision on Muscovy duck performance,excreta corticosterone metabolites(ECM),behavior,and blood parameters.Methods A total of 1263-day-old female Muscovy ducklings were allotted to 18 pens(6 replicates/treatment,7 birds/pen)and assigned to 3 experimental treatments:a control group fed commercial feed,and two experimental treatments fed commercial feed plus the 5%(based on the expected daily feed intake,as fed basis)of BSF and YM live larvae(BSF and YM groups,respectively).A two-phase feeding program was applied:starter(from 3 to 31 days of age)and grower-finisher(from 32 to 55 days of age).The live weight,average daily gain,average daily feed intake,and feed conversion ratio were calculated.Larva consumption times were collected,and video recordings were performed during 3 periods(P)each day:the hour before(P1),during(P2),and after(P3)the larva administration.ECM were evaluated at 3,31,and 55-day-old.Finally,the total red and white blood cell counts,serum proteins,lipids,and liver and renal function serum enzymes were evaluated on 12 birds/treatment.Results The experimental treatment did not affect the growth performance of the birds(P>0.05).Larva consumption times were always similar between the two insect species,except at 14–18 days of age,were BSF larvae were consumed faster than YM larvae(P<0.001).The birds showed less walking activity during P2,and preening behavior increased in YM birds during P3.The C birds increased the attack behavior over the weeks(P<0.05).During weeks 1–3 the YM group reduced the attack frequency(P1>P3;P<0.05).Finally,the provision of live BSF and YM larvae significantly reduced the ECM at 55 days of age and the heterophil to lymphocyte ratio(P<0.05).Conclusions Live BSF and YM larva supplementation in Muscovy duck improves duck welfare,without impairing birds'growth performance. 展开更多
关键词 Behavior Cairina moschata Environmental enrichment Hermetia illucens POULTRY Tenebrio molitor WELFARE
下载PDF
Journal of Central South University
13
《Journal of Central South University》 SCIE EI CAS CSCD 2024年第2期F0002-F0002,共1页
1 Aims and scope Journal of Central South University(ISSN 2095-2899)is mainly devoted to publishing academic papers and reports that are of creativeness and present the latest achievement of scientific research in suc... 1 Aims and scope Journal of Central South University(ISSN 2095-2899)is mainly devoted to publishing academic papers and reports that are of creativeness and present the latest achievement of scientific research in such fields as geology,mining,metallurgy,materials,chemistry and chemical engineering,mechatronics,information,energy,traffic transportation and environment. 展开更多
关键词 devoted GEOLOGY environment.
下载PDF
Grain size and surface micro-texture characteristics and their paleoenvironmental significance of Holocene sediment in southern margin of the Gurbantunggut Desert,China
14
作者 MA Yunqiang LI Zhizhong +2 位作者 TAN Dianjia ZOU Xiaojun TAO Tonglian 《Journal of Arid Land》 SCIE CSCD 2024年第5期632-653,共22页
The southern margin of the Gurbantunggut Desert,China,is characterized by alternating layers of aeolian and alluvial deposits.Investigating the characteristics of arenaceous sediment in this area is of significant imp... The southern margin of the Gurbantunggut Desert,China,is characterized by alternating layers of aeolian and alluvial deposits.Investigating the characteristics of arenaceous sediment in this area is of significant importance for understanding the interactive processes of wind and water forces,as well as the provenance of sediment.However,there are relatively few investigations on the characteristics of such sediment at present.In this study,we researched three aeolian-alluvial interactive stratigraphic profiles and different types of surface sediment on the desert-oasis transitional zone of southern margin of the Gurbantunggut Desert.Based on the optically stimulated luminescence(OSL)dating of aeolian sand and analyses of quartz sand grain size and surface micro-texture,we explored the aeolian-alluvial environmental change at southern margin of the desert in Holocene,as well as the provenance of sediment.The results indicated that the grain size characteristics of different types of sediment in the stratigraphic profiles were similar to those of modern dune sand,interdune sand,muddy desert surface soil,and riverbed sand.Their frequency curves were unimodal or bimodal,and cumulative probability curves were two-segment or three-segment,mainly composed of suspension load and saltation load.The quartz sand in the sediment at southern margin of the desert had undergone alternating transformation of various exogenic forces,with short transportation distance and time,and sedimentary environment was relatively humid.In Holocene,southern margin of the desert primarily featured braided river deposits,and during intermittent period of river activity,there were also aeolian deposits such as sand sheet deposits,stabilized dune deposits,and mobile dune deposits.The provenance for Holocene alluvial deposits at southern margin of the desert remains relatively constant,with the debris of the Tianshan Mountains being the primary provenance.Aeolian sand is mainly near-source recharge,which is formed by in situ deposition of fluvial or lacustrine materials in southern margin of the desert transported by wind erosion,and its provenance was still the weathered debris of the Tianshan Mountains.In addition,the sand in interior of the desert may be transported by northwest wind in desert-scale,thus affecting the development of dunes in southern margin of the desert.The results of this study provide a reference for understanding the composition and provenance changes of desert sand in the context of global climate change. 展开更多
关键词 aeolian-alluvial deposition grain size surface micro-texture sedimentary environment HOLOCENE
下载PDF
Correlation Study on Grain Size Characteristics and Geotechnical Properties of Surface Sediments in Qingdao Offshore Area
15
作者 LI Anlong WANG Panpan +5 位作者 GUO Xijun JI Xiangkun SHEN Kunming LIN Lin YAN Zhichao YUAN Lin 《Journal of Ocean University of China》 SCIE CAS CSCD 2024年第3期721-730,共10页
The comprehension of sediment grain size parameters and the corresponding sedimentary environment holds paramount importance in elucidating the engineering geological attributes of the subaqueous seabed.This study del... The comprehension of sediment grain size parameters and the corresponding sedimentary environment holds paramount importance in elucidating the engineering geological attributes of the subaqueous seabed.This study delineated the sedimentary environment zoning in the northern sea area of Qingdao through cluster analysis of grain size parameters derived from 123 surface sediment samples.The study analyzed the correlation between sediment geotechnical indices and grain size parameters across diverse sedimentary environments.A correlation equation was established for samples exhibiting a strong correlation.The study found four distinct sedimentary environments in the study area:coastal,transitional,shallow sea,and residual.Within the same sedimentary environment,the average grain size and sorting coefficient exhibit significant correlations with geotechnical indices such as water content,density,shear strength,plastic limit,liquid limit,and plastic index.However,notable disparities in the correlation between grain size parameters and geotechnical indices emerge across different sedimentary environments. 展开更多
关键词 grain size parameters cluster analysis sedimentary environment CORRELATIONS geotechnical indexes
下载PDF
Assessment of Wet Season Precipitation in the Central United States by the Regional Climate Simulation of the WRFG Member in NARCCAP and Its Relationship with Large-Scale Circulation Biases
16
作者 Yating ZHAO Ming XUE +2 位作者 Jing JIANG Xiao-Ming HU Anning HUANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第4期619-638,共20页
Assessment of past-climate simulations of regional climate models(RCMs)is important for understanding the reliability of RCMs when used to project future regional climate.Here,we assess the performance and discuss pos... Assessment of past-climate simulations of regional climate models(RCMs)is important for understanding the reliability of RCMs when used to project future regional climate.Here,we assess the performance and discuss possible causes of biases in a WRF-based RCM with a grid spacing of 50 km,named WRFG,from the North American Regional Climate Change Assessment Program(NARCCAP)in simulating wet season precipitation over the Central United States for a period when observational data are available.The RCM reproduces key features of the precipitation distribution characteristics during late spring to early summer,although it tends to underestimate the magnitude of precipitation.This dry bias is partially due to the model’s lack of skill in simulating nocturnal precipitation related to the lack of eastward propagating convective systems in the simulation.Inaccuracy in reproducing large-scale circulation and environmental conditions is another contributing factor.The too weak simulated pressure gradient between the Rocky Mountains and the Gulf of Mexico results in weaker southerly winds in between,leading to a reduction of warm moist air transport from the Gulf to the Central Great Plains.The simulated low-level horizontal convergence fields are less favorable for upward motion than in the NARR and hence,for the development of moist convection as well.Therefore,a careful examination of an RCM’s deficiencies and the identification of the source of errors are important when using the RCM to project precipitation changes in future climate scenarios. 展开更多
关键词 NARCCAP Central United States PRECIPITATION low-level jet large-scale environment diurnal variation
下载PDF
Genetic pathways in cerebral palsy:a review of the implications for precision diagnosis and understanding disease mechanisms
17
作者 Yiran Xu Yifei Li +2 位作者 Seidu A.Richard Yanyan Sun Changlian Zhu 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第7期1499-1508,共10页
Ce rebral palsy is a diagnostic term utilized to describe a group of permanent disorders affecting movement and posture.Patients with cerebral palsy are often only capable of limited activity,resulting from non-progre... Ce rebral palsy is a diagnostic term utilized to describe a group of permanent disorders affecting movement and posture.Patients with cerebral palsy are often only capable of limited activity,resulting from non-progressive disturbances in the fetal or neonatal brain.These disturbances severely impact the child’s daily life and impose a substantial economic burden on the family.Although cerebral palsy encompasses various brain injuries leading to similar clinical outcomes,the unde rstanding of its etiological pathways remains incomplete owing to its complexity and heterogeneity.This review aims to summarize the current knowledge on the genetic factors influencing cerebral palsy development.It is now widely acknowledged that genetic mutations and alterations play a pivotal role in cerebral palsy development,which can be further influenced by environmental fa ctors.Des pite continuous research endeavors,the underlying fa ctors contributing to cerebral palsy remain are still elusive.However,significant progress has been made in genetic research that has markedly enhanced our comprehension of the genetic factors underlying cerebral palsy development.Moreove r,these genetic factors have been categorized based on the identified gene mutations in patients through clinical genotyping,including thrombosis,angiogenesis,mitochondrial and oxidative phosphorylation function,neuronal migration,and cellular autophagy.Furthermore,exploring targeted genotypes holds potential for precision treatment.In conclusion,advancements in genetic research have substantially improved our understanding of the genetic causes underlying cerebral palsy.These breakthroughs have the potential to pave the way for new treatments and therapies,consequently shaping the future of cerebral palsy research and its clinical management.The investigation of cerebral palsy genetics holds the potential to significantly advance treatments and management strategies.By elucidating the underlying cellular mechanisms,we can develop to rgeted interventions to optimize outcomes.A continued collaboration between researchers and clinicians is imperative to comprehensively unravel the intricate genetic etiology of cerebral palsy. 展开更多
关键词 cerebral palsy environmental factors ETIOLOGY genetic factors genetic mutation movement disorder spastic diplegia
下载PDF
Predict the evolution of mechanical property of Al-Li alloys in a marine environment
18
作者 Wei Li Lin Xiang +6 位作者 Guang Wu Hongli Si Jinyan Chen Yiming Jin Yan Su Jianquan Tao Chunyang Huang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第1期557-566,共10页
The ocean is one of the essential fields of national defense in the future,and more and more attention is paid to the lightweight research of Marine equipment and materials.This study it is to develop a Machine learni... The ocean is one of the essential fields of national defense in the future,and more and more attention is paid to the lightweight research of Marine equipment and materials.This study it is to develop a Machine learning(ML)-based prediction method to study the evolution of the mechanical properties of Al-Li alloys in the marine environment.We obtained the mechanical properties of Al-Li alloy samples under uniaxial tensile deformation at different exposure times through Marine exposure experiments.We obtained the strain evolution by digital image correlation(DIC).The strain field images are voxelized using 2D-Convolutional Neural Networks(CNN)autoencoders as input data for Long Short-Term Memory(LSTM)neural networks.Then,the output data of LSTM neural networks combined with corrosion features were input into the Back Propagation(BP)neural network to predict the mechanical properties of Al-Li alloys.The main conclusions are as follows:1.The variation law of mechanical properties of2297-T8 in the Marine atmosphere is revealed.With the increase in outdoor exposure test time,the tensile elastic model of 2297-T8 changes slowly,within 10%,and the tensile yield stress changes significantly,with a maximum attenuation of 23.6%.2.The prediction model can predict the strain evolution and mechanical response simultaneously with an error of less than 5%.3.This study shows that a CNN/LSTM system based on machine learning can be built to capture the corrosion characteristics of Marine exposure experiments.The results show that the relationship between corrosion characteristics and mechanical response can be predicted without considering the microstructure evolution of metal materials. 展开更多
关键词 Marine environment Al-Li alloy Machine learning CORROSION
下载PDF
High-temperature corrosion of sintered RE_(2)Si_(2)O_(7)(RE=Yb and Ho)environmental barrier coating materials by volcanic ash
19
作者 Ayahisa Okawa Son Thanh Nguyen +7 位作者 Tadachika Nakayama Thi-Mai-Dung Do Hisayuki Suematsu Shu Yin Takuya Hasegawa Tsuneo Suzuki Takashi Goto Koichi Niihara 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第7期1628-1638,共11页
Rare-earth silicates are promising environmental barrier coatings(EBCs)that can protect SiC_(f)/Si C_(m)substrates in next-genera tion gas turbine blades.Notably,RE_(2)Si_(2)O_(7)(RE=Yb and Ho)shows potential as an EB... Rare-earth silicates are promising environmental barrier coatings(EBCs)that can protect SiC_(f)/Si C_(m)substrates in next-genera tion gas turbine blades.Notably,RE_(2)Si_(2)O_(7)(RE=Yb and Ho)shows potential as an EBC due to its coefficient of thermal expansion(CTE)compatible with substrates and high resistance to water vapor corrosion.The target operating temperature for next-generation tur bine blades is 1400°C.Corrosion is inevitable during adhesion to molten volcanic ash,and thus,understanding the corrosion behavior o the material is crucial to its reliability.This study investigates the high-temperature corrosion behavior of sintered RE_(2)Si_(2)O_(7)(RE=Yb and Ho).Samples were prepared using a solid-state reaction and hot-press method.They were then exposed to volcanic ash at 1400°C for 224,and 48 h.After 48 h of exposure,volcanic ash did not react with Yb_(2)Si_(2)O_(7)but penetrated its interior,causing damage.Meanwhile Ho_(2)Si_(2)O_(7)was partially dissolved in the molten volcanic ash,forming a reaction zone that prevented volcanic ash melts from penetrating the interior.With increasing heat treatment time,the reaction zone expanded,and the thickness of the acicular apatite grains increased The Ca:Si ratios in the residual volcanic ash were mostly unchanged for Yb_(2)Si_(2)O_(7)but decreased considerably over time for Ho_(2)Si_(2)O_(7).Th Ca in volcanic ash was consumed and formed apatite,indicating that RE^(3+)ions with large ionic radii(Ho>Yb)easily precipitated apatit from the volcanic ash. 展开更多
关键词 environmental barrier coating volcanic ash rare-earth disilicate CORROSION
下载PDF
Influence of edaphic factors on distribution and condition of Himalayan silver birch(Betula utilis D.Don)communities in the northwestern Indian Himalayas
20
作者 Khashti DASILA Renu RAWAL +3 位作者 Tanay BARMAN Sher Singh SAMANT Anita PANDEY Veena PANDE 《Journal of Mountain Science》 SCIE CSCD 2024年第2期590-606,共17页
The basic concept of phytosociology is crucial for the assessment of species composition and dynamic ecological succession of forests supporting ecological services,functions,disturbance,and resilience that lead to th... The basic concept of phytosociology is crucial for the assessment of species composition and dynamic ecological succession of forests supporting ecological services,functions,disturbance,and resilience that lead to the development of integrated areas such as ecological niche modeling and contribute to identifying the valuable bio-indicators which can be used in framing conservation and management planning.B.utilis is one of the most dominant tree species of treeline ecotone in the Himalayan Region.The species is also considered as indicator species for monitoring the past and recent climate change impact.The current study was carried out in the natural populations of B.utilis from the sub-alpine zone of North-western Indian Himalaya.The birch dominated forest harbors a total of 305 plant species comprising Angiosperms(51 families,160 genera and 277 species),Gymnosperms(03 families,05 genera and 07 species)and Pteridophytes(07 families,11 genera and 21 species)with Asteraceae,Ranunculaceae and Rosaceae as dominant family.Birch forests are found dominant in shady moist habitat and North West aspect.Geographical characteristics,anthropogenic and developmental activities affect the population structure of B.utilis and associated species.However,the species has fair regeneration status in the study area.The acidic nature of soil pH and spatial variation in edaphic characteristics may be due to geographical differences,rooting patterns and litter accumulation of below and above-ground vegetation.Biomass estimation of a representative population of B.utilis from each site showed that TAGBD,TCD and TBD were found maximum in ST3(Hamta Pass II site).The CCA analysis determined that environmental variables such as altitude,organic matter,available phosphorous,organic carbon,available nitrogen,and electrical conductivity played a significant role in determining tree species composition and distribution in B.utilis dominated forests. 展开更多
关键词 Species composition Indicator species Biomass North-western Indian Himalaya Regeneration Environmental variables
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部