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Grassland-type ecosystem stability in China differs under the influence of drought and wet events

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Journal of Arid Land 2024年第5期16卷 615-631页

作者： cao wenyu BAI Jianjun YU Leshan School of Geography and Tourism Shaanxi Normal UniversityXi'an 710119China International Business School Shaanxi Normal UniversityXi'an 710119China

Ecological stability is a core issue in ecological research and holds significant implications forhumanity. The increased frequency and intensity of drought and wet climate events resulting from climatechange pose a major threat to global ecological stability. Variations in stability among different ecosystemshave been confirmed, but it remains unclear whether there are differences in stability within the sameterrestrial vegetation ecosystem under the influence of climate events in different directions and ***'s grassland ecosystem includes most grassland types and is a good choice for studying this *** study used the Standardized Precipitation Evapotranspiration Index-12 (SPEI-12) to identify thedirections and intensities of different types of climate events, and based on Normalized DifferenceVegetation Index (NDVI), calculated the resistance and resilience of different grassland types for 30consecutive years from 1990 to 2019 (resistance and resilience are important indicators to measurestability). Based on a traditional regression model, standardized methods were integrated to analyze theimpacts of the intensity and duration of drought and wet events on vegetation stability. The resultsshowed that meadow steppe exhibited the highest stability, while alpine steppe and desert steppe had thelowest overall stability. The stability of typical steppe, alpine meadow, temperate meadow was at anintermediate level. Regarding the impact of the duration and intensity of climate events on vegetationecosystem stability for the same grassland type, the resilience of desert steppe during drought was mainlyaffected by the duration. In contrast, the impact of intensity was not significant. However, alpine steppewas mainly affected by intensity in wet environments, and duration had no significant impact. Ourconclusions can provide decision support for the future grassland ecosystem governance.

关键词： grassland ecosystem stability resistance resilience different climate types drought climate event wet climate event

Dynamic impact properties of deep sandstone under thermal-hydraulicmechanical coupling loads

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Journal of Mountain Science 2024年第6期21卷 2113-2129页

作者： cao Chunhui DING Haonan ZOU Baoping School of Civil Engineering and Architecture Zhejiang University of Science and TechnologyHangzhou 310023China Zhejiang-Singapore Joint Laboratory for Urban Renewal and Future City Hangzhou 310023China

The deep rock mass within coal mines situated in a challenging environment are characterized by high ground stress,high geotemperature,high osmotic water pressure,and dynamic disturbances from mechanical *** investigate the impact of this complex mechanical environment on the dynamic characteristics of roof sandstone in self-formed roadways without coal pillars,standard specimens of deep sandstone from the 2611 upper tunnel working face of the Yongmei Company within the Henan Coal Chemical Industry Group in Henan,China were prepared,and an orthogonal test was *** a self-developed geotechnical dynamic impact mechanics test system,triaxial dynamic impact tests under thermal-hydraulicmechanical coupling conditions were conducted on deep *** results indicate that under high confining pressure,deep sandstone exhibits pronounced brittle failure at low temperatures,with peak strength gradually decreasing as temperature and osmotic water pressure ***,under low confining pressure and low temperature,the brittleness of deep sandstone weakens gradually,while ductility ***,sandstone demonstrates higher peak strength at low temperatures under high axial pressure conditions,lower peak strength at high temperatures,and greater strain under low axial pressure and high osmotic water *** in impact air pressure and osmotic water pressure have proportionally greater effects on peak stress and peak *** 50%of the input strain energy is utilized as effective energy driving the sandstone fracture *** analysis identifies the optimal combination of factors affecting the peak stress and peak strain of *** the coupling effect,intergranular and transgranular fractures occur within the *** images illustrate that the damage forms range from minor damage with multiple fissures to extensive fractures and severe *** study elucidates the varied dynamic impact me

关键词： Deep sandstone Thermal-hydraulicmechanical coupling Dynamic impact Stress-strain Failure Modes Polar analysis

A Support Data-Based Core-Set Selection Method for Signal Recognition

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China Communications 2024年第4期21卷 151-162页

作者： Yang Ying Zhu Lidong cao Changjie National Key Laboratory of Wireless Communications(University of Electronic Science and Technology of China) Chengdu 611731China College of Computer Science and Cyber Security(Chengdu University of Technology) Chengdu 610059China College of Mathmatics and Physics(Chengdu University of Technology) Chengdu 610059China

In recent years,deep learning-based signal recognition technology has gained attention and emerged as an important approach for safeguarding the electromagnetic ***,training deep learning-based classifiers on large signal datasets with redundant samples requires significant memory and high *** paper proposes a support databased core-set selection method(SD)for signal recognition,aiming to screen a representative subset that approximates the large signal ***,this subset can be identified by employing the labeled information during the early stages of model training,as some training samples are labeled as supporting data *** support data is crucial for model training and can be found using a border sample *** results demonstrate that the SD method minimizes the impact on model recognition performance while reducing the dataset size,and outperforms five other state-of-the-art core-set selection methods when the fraction of training sample kept is less than or equal to 0.3 on the RML2016.04C dataset or 0.5 on the RML22 *** SD method is particularly helpful for signal recognition tasks with limited memory and computing resources.

关键词： core-set selection deep learning model training signal recognition support data

Enzymatic C1 reduction using hydrogen in cofactor regeneration

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Frontiers of Chemical Science and Engineering 2024年第7期18卷 33-40页

作者： Ruishuang Sun Chenqi cao Qingyun Wang Hui cao Ulrich Schwaneberg Yu Ji Luo Liu Haijun Xu Beijing Bioprocess Key Laboratory Beijing University of Chemical TechnologyBeijing 100029China Institute of Biotechnology Rheinisch-Westfälische Technische Hochschale(RWTH)AachenAachen 52074Germany

Carbon dioxide fixation presents a potential solution for mitigating the greenhouse gas *** carbon dioxide fixation,C1 compound reduction requires a high energy *** calculations suggest that the energy source for cofactor regeneration plays a vital role in the effective enzymatic C1 *** utilizes renewable hydrogen to achieve the regeneration and supply cofactor nicotinamide adenine dinucleotide(NADH),providing a driving force for the reduction reaction to reduce the thermodynamic barrier of the reaction cascade,and making the forward reduction pathway thermodynamically *** on the regeneration of cofactor NADH by hydrogenase,and coupled with formaldehyde dehydrogenase and formolase,a favorable thermodynamic mode of the C1 reduction pathway for reducing formate to dihydroxyacetone(DHA)was designed and *** resulted in accumulation of 373.19μmol·L^(-1) DHA after 2 h,and conversion reaching 7.47%.These results indicate that enzymatic utilization of hydrogen as the electron donor to regenerate NADH is of great significance to the sustainable and green development of bio-manufacturing because of its high economic efficiency,no by-products,and environment-friendly ***,formolase efficiently and selectively fixed the intermediate formaldehyde(FALD)to DHA,thermodynamically pulled formate to efficiently reduce to DHA,and finally stored the low-grade renewable energy into chemical energy with high energy density.

关键词： [NiFe]-hydrogenase SH formolase NADH regeneration C1 compound reduction thermodynamic calculation

Effect of preload forces on multidimensional signal dynamic behaviours for battery early safety warning

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Journal of Energy Chemistry 2024年第5期92卷 484-498页

作者： Kuijie Li Jiahua Li Xinlei Gao Yao Lu Depeng Wang Weixin Zhang Weixiong Wu Xuebing Han Yuan-cheng cao Languang Lu Jinyu wen Shijie Cheng Minggao Ouyang School of Electrical and Electronic Engineering Huazhong University of Science and TechnologyWuhan 430074HubeiChina State Key Laboratory of Automotive Safety and Energy Tsinghua UniversityBeijing 100084China Energy and Electricity Research Center Jinan UniversityZhuhai 519070GuangdongChina Department of Mechanical Engineering Imperial College LondonLondon.SW7:2AZ.UK

Providing early safety warning for batteries in real-world applications is *** this study,comprehensive thermal abuse experiments are conducted to clarify the multidimensional signal evolution of battery failure under various preload *** time-sequence relationship among expansion force,voltage,and temperature during thermal abuse under five categorised stages is *** characteristic peaks are identified for the expansion force,which correspond to venting,internal short-circuiting,and thermal *** particular,an abnormal expansion force signal can be detected at temperatures as low as 42.4°C,followed by battery thermal runaway in approximately 6.5 ***,reducing the preload force can improve the effectiveness of the early-warning method via the expansion ***,reducing the preload force from 6000 to 1000 N prolongs the warning time(i.e.,227 to 398 s)before thermal runaway is *** on the results,a notable expansion force early-warning method is proposed that can successfully enable early safety warning approximately 375 s ahead of battery thermal runaway and effectively prevent failure propagation with module *** study provides a practical reference for the development of timely and accurate early-warning strategies as well as guidance for the design of safer battery systems.

关键词： Lithium-ion battery Thermal runaway Preload force Expansionforce Early warning Multidimensional signal

Impacts of pancreatic exocrine insufficiency on gut microbiota

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2024年第4期25卷 271-279页

作者： Yulin GUO Feng cao Fei LI Department of General Surgery Xuanwu Hospital of Capital Medical UniversityBeijing 100053China Acute Pancreatitis Clinical Center of Capital Medical University Beijing 100053China

Pancreatic exocrine insufficiency(PEI)can be induced by various kinds of diseases,including chronic pancreatitis,acute pancreatitis,and *** main pathogenetic mechanism of PEI involves the decline of trypsin synthesis,disorder of pancreatic fluid flow,and imbalance of secretion *** studies have shown that PEI could induce gut bacterial overgrowth and dysbiosis,with the abundance of Lactobacillus and Bifidobacterium increasing the most,which could be partially reversed by pancreatic enzyme replacement *** studies have also confirmed the association between PEI and the dysbiosis of gut *** exocrine secretions and changes in duodenal p H as well as bile salt malabsorption brought about by PEI may affect and shape the abundance and composition of gut *** turn,the gut microbiota may impact the pancreatic exocrine acinus through potential bidirectional *** forward,more and higher-quality studies are needed that focus on the mechanism underlying the impact of PEI on the gut microbiota.

关键词： Pancreatic exocrine insufficiency Gut microbiota Gut microbiome Pancreatic enzyme replacement therapy

Taphonomy and Paleoecology of Lycoptera: A Case Study from the Lower Jehol Group in Western Liaoning, Northeastern China

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Journal of Earth Science 2024年第3期35卷 737-746页

作者： Zhongwu Lan Rong cao Shujing Zhang State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and PalaeontologyChinese Academy of SciencesNanjing 210008China State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesWuhan 430078China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Department of Geology Trinity CollegeDublin 999015Ireland

Taphonomy and paleoecology(biological behavior)of the Early Cretaceous fish fossils are poorly *** study reports for the first time a detailed taphonomical and paleoecological study on Lycoptera in the Mesozoic strata of western Liaoning Province,NE *** XRD analysis shows that gismondine is the dominant clay minerals that could have contributed to the preservation of Lycoptera fossils and microbial mat fragments in the fossil-bearing *** may have formed under volcanism-related hydrothermal regime that was transformed from crystal and lithic ***μ-XRF imaging analysis shows a dominant chemical composition of Al,Si,P,S,Rh,K,Ca,Ti,C,Cr,Mn,Fe,Ni,among which P,Ca,C and S are enriched in the fish skeleton in comparison to the *** suggests a dominant apatite composition for the fish *** influence did not smear off these organic signals probably because of protection of *** coexistance of C and S with Ni is assumed to represent recovered primary productivity following volcanic explosions and toxic gas *** head of juvenile fish stays close to the body of adult *** further discoveries,such phenomenon is interpreted to suggest that adult fish actively protected juvenile fish in the presence of environmental pressures such as anoxia and deterioration of water quality induced by *** acidification and hypoxia in association with volcanism created a harmful environment causing mass extinction of *** adult Lycoptera protected their juveniles by its body at the moment before *** biological behavior will be increasingly reported given the wide occurrence of Lycoptera in Mesozoic strata.

关键词： Lycoptera taphonomy paleoecology fish Jehol Group NE China.

Experimental Study of Temperature Control Based on Composite Phase Change Materials during Charging and Discharging of Battery

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Journal of Thermal Science 2024年第2期33卷 578-590页

作者： LI Xiaolin WANG Jun cao wenxiang ZHANG Xuesong School of Automotive and Traffic Engineering Jiangsu UniversityZhenjiang212013China

This study is to utilize the heat-absorbing and releasing capabilities of phase change materials(PCM)to regulate the surface temperature fluctuations of batteries during charging and *** goal is to keep the battery within the optimal operating temperature *** impact of PCM thickness and phase change temperature on battery temperature is investigated by encircling a cylindrical battery with a PCM *** improve the thermal conductivity of PCM,expanded graphite(EG) is added to make a composite phase change material(CPCM),and the effects of various EG mass ratios on battery surface temperature and CPCM utilization level are *** findings indicate that increasing PCM thickness effectively extends temperature control time,but its impact is *** difference in phase change temperature of PCM controls the battery temperature in different temperature *** phase change temperatures are unsuitable for controlling battery temperature in high temperature *** addition of EG enhances the thermal conductivity of PCM,leading to further control of battery *** results show that the addition of 6%(mass ratio) EG to CPCM extends the effective temperature control time by 11 min and improves by 28% compared to a single *** CPCM utilization is also more satisfactory and achieved a balance between heat storage and thermal conductivity in a battery thermal management system(BTMS) based on PCM.

关键词： phase change material expanded graphite thermal management system effective control time

Advanced Design of Soft Robots with Artificial Intelligence

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Nano-Micro Letters 2024年第10期16卷 474-521页

作者： Ying cao Bingang Xu Bin Li Hong Fu Nanotechnology Center School of Fashion and TextilesThe Hong Kong Polytechnic UniversityHong Kong 999077People's Republic of China Department of Mathematics and Information Technology The Education University of Hong KongHong Kong 999077People's Republic of China Bioinspired Engineering and Biomechanics Center Xi'an Jiaotong UniversityXi'an 710049People's Republic of China

In recent years,breakthrough has been made in the field of artificial intelligence(AI),which has also revolutionized the industry of *** robots featured with high-level safety,less weight,lower power consumption have always been one of the research ***,multifunctional sensors for perception of soft robotics have been rapidly developed,while more algorithms and models of machine learning with high accuracy have been optimized and *** of soft robots with AI have also been advanced ranging from multimodal sensing,human-machine interaction to effective actuation in robotic ***-less,comprehensive reviews concerning the new developments and strategies for the ingenious design of the soft robotic systems equipped with AI are ***,the new development is systematically reviewed in the field of soft robots with ***,background and mechanisms of soft robotic systems are briefed,after which development focused on how to endow the soft robots with AI,including the aspects of feeling,thought and reaction,is ***,applications of soft robots with AI are systematically summarized and discussed together with advanced strategies proposed for performance *** thoughts for future intelligent soft robotics are pointed ***,some perspectives are put forward.

关键词： Soft robotic systems Artificial intelligence Design tactics Review and perspective