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Human disturbance exacerbated erosion and deposition in the karst peak-cluster depressions during the Ming and Qing dynasties

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Science China Earth Sciences 2024年第11期67卷 3550-3561页

作者： Shuai YUAN Yuemin YUE Xinbao ZHANG lu wang lu ZHAI Kelin wang Key Laboratory for Agro-Ecological Processes in Subtropical Region Institute of Subtropical Agriculture Chinese Academy of Sciences Huanjiang Observation and Research Station for Karst Ecosystems Chinese Academy of Sciences University of Chinese Academy of Sciences Institute of Mountain Hazards and Environment Ministry of Water Resources Chinese Academy of Sciences State Key Laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences

Under the background of large-scale ecological restoration, China's southwestern karst region has become a hotspot of global vegetation cover “greening” in the past 20 years. However, because of geological constraints, it is difficult to restore the forest landscapes in some areas. It is urgent to understand the impacts of human disturbances during the historical period on the difficult-to-forestation rocky-desertification areas of the karst region in order to guide future afforestation. In this study, we quantified the changes of specific sediment yield in typical karst depressions over the past 500 years by using137Cs,210Pb, and14C dating methods in karst depressions, and identified the main human disturbances related to historical erosion and sedimentation by combining with historical data. The results showed that the erosion and sedimentation of the three depressions in 1921–1963 were significantly higher than that in 1963–2021, and the sedimentation rate(0.64–1.33 cm a-1) and the specific sediment yield(2.51–13.11 t ha-1a-1) during Ming and Qing dynasties（1504–1812） were higher than the sedimentation rate(0.26–0.95 cm a-1) and specific sediment yield(0.95–6.99 t ha-1a-1) in the recent century（1921–2021）. Reconstruction data and literature from the Ming and Qing dynasties show an empirical link between changes in population, arable land, food, forest area,and deforestation events during the same period. It was found that the population and arable land in Guangxi increased more than three-fold and the forest area decreased significantly in the 17th century after the migration of the Yao ethnic group and the introduction of maize to the region, which may be the main reason for intensifying the erosion of depressions. This study is of great significance to understanding the evolution history of rocky desertification in this region and to answer the potential of afforestation.

关键词： Karst region 14C dating Peak-cluster depressions Ethnic minirity migration Specific sediment yield

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Evolutionary game analysis of information service quality control of e-commerce platforms under information ecology

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Journal of Management Analytics 2024年第1期11卷 135-159页

作者： Xiaojun Xu lu wang Xiaoli wang School of Economics and Management Yanshan UniversityQinhuangdaoPeople’s Republic of China

Due to the information asymmetry and imperfect supervision system,the problem of information service quality of e-commerce platforms is becoming increasingly *** on the perspective of information ecology,this paper constructs a three-party evolutionary game model including merchants,e-commerce platforms and governments,and analyzes the dynamic process of the threeparty game under bounded rationality,thereby characterizing the behavior and optimal strategies of information service quality *** carry out numerical simulation using data of the Pinduoduo *** results show that the cost of each party,control strength of e-commerce platforms,proportion of margin deducted and other factors are important factors affecting the quality of information service;Only when the sum of the costs of passive management of e-commerce platforms,penalties for merchants,and the additional revenue generated from the active management exceeds the cost of the active management of the e-commerce platforms,it ensures effective control over the quality of information service in a stable market ***,some suggestions are put forward to optimize the e-commerce information service quality control.

关键词： E-commerce platforms information service quality control evolutionary game information ecology

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Effect of Sintering Temperature on the Microstructure and Mechanical Properties of Nanocrystalline Cemented Carbide

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Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 664-672页

作者：陈先富刘颖 YE Jinwen wang lu School of Materials Science and Engineering Sichuan UniversityChengdu 610065China Key Laboratory of Advanced Special Ma-terial&Technology Ministry of EducationChengdu 610065China

WC-Co nanocrystalline nitrogen-containing cemented carbides were prepared by vacuum sintering and low pressure *** sintering processes of Cr_(2)(C,N)doped nano WC-Co powders were studied by using thermogravimetric analysis(TGA)and differential scanning calorimetry(DSC).The effect of sintering temperature on the microstructure and mechanical properties of nanocrystalline cemented carbide was studied by scanning electron microscope(SEM),high resolution transmission electron microscope(HRTEM)and mechanical property *** results showed that the nano WC grains began to grow in the solid phase sintering stage.A high-performance nano-nitrogen-containing cemented carbide with uniform microstructure and good interfacial bonding can be obtained by increasing the sintering temperature to 1380℃.It has a transverse rupture strength(TRS)of 5057 MPa and a hardness of 1956 HV30.

关键词： nano nitrogen cemented carbide sintering temperature microstructure mechanical properties

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Asymmetric copolyimide membranes fabricated by nonsolvent-induced phase separation for He/CH_(4) and He/N_(2) separation

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Frontiers of Chemical Science and Engineering 2024年第4期18卷 97-106页

作者： Ying Li lu wang Junyan Xie Yong Dai Xuehong Gu Xuerui wang State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringNanjing Tech UniversityNanjing 211816China Quzhou Membrane Material Innovation Institute Quzhou 324000China

Membrane gas separation is considered an energy-saving technique to extract He from natural gas due to no phase change and room temperature ***,the membrane performance was strongly limited by the trade-off between permeance and ***,novel 4,4′-(hexafluoroisopropylidene)diphthalic anhydride(6FDA)-2,2′-bis(3-amino-4-hydroxyphenyl)hexafluoropropane(APAF)-5-amino-2-(4-aminobenzene)benzimidazole(BIA)asymmetric membranes with a thickness of 300 nm were successfully prepared by the non-solvent induced phase separation *** membrane performance was modulated by regulating dope solution compositions(e.g.,tetrahydrofuran and polymer concentration).The ideal He/CH_(4) selectivity was 124 and the optimized He permeance reached 87 GPU,beyond the current upper ***/CH_(4) selectivity was 75 and He permeance was 73 GPU for the binary mixture feed containing 0.2 mol%*** membrane showed good resistance to CO_(2) and C_(2)H_(6),which are the typical impurities in natural *** 6FDA-APAF-BIA membranes have good stability(>160 h),which can provide great potential in He extraction from natural gas.

关键词： He separation membrane natural gas copolyimide

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Progress and challenges of electrolyte modulation in aqueous zinc-ion batteries

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Rare Metals 2024年第7期43卷 2940-2967页

作者： Qi-Hang Yang lu-Fei wang Xiao-Yu wang Meng-Meng Zhen Tianjin Key Laboratory of Clean Energy and Pollution Control School of Energy and Environmental EngineeringHebei University of TechnologyTianjin 300071China

As a new type of green battery system,aqueous zinc-ion batteries(AZIBs)have gradually become a research hotspot due to their low cost,high safety,excellent stability,high theoretical capacity(820 mAh·g^(-1))of zinc anode,and low redox potential(-0.76 V *** hydrogen electrode(SHE)).AZIBs have been expected to be an alternative to lithium-ion batteries for large-scale commercial energy storage ***,they are facing thorny issues such as degradation of cycling performance,zinc dendrites,and side *** the same time,these problems cause short cycling life of batteries,thus severely limiting their commercial *** recent years,many more researches have been conducted on the modification of anode and cathode materials of AZIBs,but there is a lack of in-depth discussion on the characteristics and mechanism of electrolyte *** this review,we will make a systematic summary of the current problems with two electrodes in AZIBs,as well as the types and functions of electrolyte ***,we further systematically describe the modulation mechanism of electrolyte additives in the performance of the cathode and *** prospects and development directions of additive modulation strategies for AZIBs electrolytes are prospected.

关键词： Electrolyte additives Aqueous zinc-ion batteries Zinc anode protection Cathode chemistry

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Creep constitutive model considering nonlinear creep degradation of fractured rock

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International Journal of Mining Science and Technology 2024年第1期34卷 105-116页

作者： wang Chunping Liu Jianfeng Chen Liang Liu Jian wang lu Liao Yilin Beijing Research Institute of Uranium Geology Beijing 100029China CAEA Innovation Center for Geological Disposal of High-Level Radioactive Waste Beijing 100029China State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan UniversityChengdu 610065China School of Architecture and Civil Engineering Xihua UniversityChengdu 610039China

Stability analysis of underground constructions requires a model study of rock masses’ long-term performance. Creep tests under different stress conditions was conducted on intact granite and granite samples fractured at 30° and 45° angles. The experimental results indicate that the steady creep strain rates of intact and fractured rock present an exponential increase trend with the increase of stress level. A nonlinear creep model is developed based on the experimental results, in which the initial damage caused by fracture together with the damage caused by constant load have been taken into consideration. The fitting analysis results indicated that the model proposed is more accurate at identifying the full creep regions in fractured granite, especially the accelerated stage of creep deformation. The least-square fit error of the proposed creep model is significantly lower than that of Nishihara model by almost an order of magnitude. An analysis of the effects of elastic modulus, viscosity coefficient, and damage factors on fractured rock strain rate and creep strain is conducted. If no consideration is given to the effects of the damage, the proposed nonlinear creep model can degenerate into to the classical Nishihara model.

关键词： Fractured rock Damage Creep Beishan granite Geological disposal

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Temperature dependence of mechanical properties and damage evolution of hot dry rocks under rapid cooling

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 645-660页

作者： Longjun Dong Yihan Zhang Lichang wang lu wang Shen Zhang School of Resources and Safety Engineering Central South UniversityChangsha410083China School of Geosciences and Info-physics Central South UniversityChangsha410083China

Understanding the differences in mechanical properties and damage characteristics of granitoid under high temperatures is crucial for exploring deep geothermal *** study analyzes the evolution of the acoustic emission(AE)characteristics and mechanical parameters of granodiorite and granite after heating and water cooling by uniaxial compression and variable-angle shear tests under different temperature *** identify their changes in mesostructure and mineral composition with electron probe microanalysis and scanning electron *** show that these two hot dry rocks have similar diagenetic minerals and microstructure,but show significantly different mechanical and acoustic characteristics,and even opposing evolution trends in a certain temperature *** the temperatures ranging from 100℃to 500℃,the compressive and shear mechanical properties of granodiorite switch repeatedly between weakening and strengthening,and those of granite show a continuous weakening *** 600℃,both rocks exhibit a deterioration of mechanical *** damage mode of granite is characterized by initiating at low stress,exponential evolutionary activity,and intensified energy *** contrast,granodiorite exhibits the characteristics of initiating at high stress,volatile evolutionary activity,and intermittent energy release,due to its more stable microstructure and fewer thermal defects compared to *** the temperature increases,the initiation and propagation of secondary cracks in granodiorite are suppressed to a certain extent,and the seismicity and brittleness are *** subtle differences in grain size,microscopic heterogeneity,and mineral composition of the two hot dry rocks determine the different acoustic-mechanical characteristics under heating and cooling,and the evolution trends with *** findings are of great significance for the scientific and efficient construction of rock mass engineering by rationally utilizin

关键词： Hot dry rock Acoustic emission Mechanical properties High temperature Damage

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Effect of(Cr,V)_(2)(C,N)on the Microstructure and Mechanical Properties of WC-10Co Cemented Carbides

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Journal of Wuhan University of Technology(Materials Science) 2024年第5期39卷 1138-1148页

作者： LI Xiangkun wang lu YE Jinwen School of Materials Science and Engineering Sichuan UniversityChengdu 610065China

WC-10Co cemented carbides with finer WC and narrower grain size distributions are produced by using(Cr,V)_(2)(C,N)as grain growth *** a result,with the increase of(Cr_(0.9),V_(0.1))_(2)(C,N)and(V_(0.9),Cr_(0.1))_(2)(C,N),the grains size of WC and mean free path of Co phase decrease,and adjacency of WC *** and homogenization of grains enhance the transverse rupture strength(TRS)and the ***,the deflection and bridging of cracks keep the fracture toughness at a respectable *** WC-10Co-0.6(Cr_(0.9),V_(0.1))_(2)(C,N)-0.025(V_(0.9),Cr_(0.1))_(2)(C,N)cemented carbides exhibit excellent comprehensive mechanical properties with the TRS of 4602.6 MPa,hardness of 1835 kg/mm^(2),and fracture toughness of 10.39 MPa·m^(1/2),***,the large pores are caused by excess N larger than 0.03 wt%and deteriorates the mechanical *** provide a new approach to WC-Co cemented carbides preparation with a narrow grain size distribution by adding novel grain growth inhibitors.

关键词： (Cr,V)_(2)(C,N) nutrient content WC grains size microstructure mechanical properties

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Surface chemical microenvironment engineering of catalysts by organic molecules for boosting electrocatalytic reaction

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Chinese Chemical Letters 2024年第8期35卷 15-24页

作者： Xianxu Chu lu wang Junru Li Hui Xu Henan Key Laboratory of Biomolecular Recognition and Sensing College of Chemistry and Chemical EngineeringShangqiu Normal UniversityShangqiu 476000China Key Laboratory of Advanced Catalytic Materials and Technology Advanced Catalysis and Green Manufacturing Collaborative Innovation CenterChangzhou UniversityChangzhou 213164China

Electrocatalysis is a surface-sensitive process,in which the catalytic activity of electrocatalyst highly re-lates to the surface adsorption/desorption behaviors of the reactants/intermediates/products on the cat-alytically active *** chemical microenvironment engineering via organic molecules functional-ization is a promising strategy to tune the electrocatalytic activity since it can well modify the elec-trode/electrolyte interface and alter the reaction *** this review,we summarize the recent progress of surface microenvironment engineering of electrocatalysts induced by organic molecules func-tionalization,with the special focus on the organic molecule-assisted growth mechanism and unique electronic *** importantly,the applications of organic molecule functionalized catalysts in var-ious electrocatalytic reactions are also systematically summarized,along with a deep discussion on the conclusion and *** work will open a new avenue for the construction and modification of advanced electrocatalysts based on organic molecule-mediated interface engineering.

关键词： Chemical microenvironment engineering Organic molecules Electrocatalysis Functionalization Interface

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Towards Achieving Carbon Neutrality: The Role of Vegetation Restoration in Karst Regions of Southwest China

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Journal of Earth Science 2024年第3期35卷 1044-1048页

作者： Yuemin Yue lu wang Xinbao Zhang Kelin wang Guangxi Key Laboratory of Karst Ecological Processes and Services Institute of Subtropical AgricultureChinese Academy of SciencesChangsha 410125China Huanjiang Observation and Research Station for Karst Ecosystem Chinese Academy of SciencesHuanjiang 547100China Chengdu Institute of Mountain Disasters and Environment Chinese Academy of Sciences&Ministry of Water ResourcesChengdu 610041China

Karst regions of Southwest China become a hotspot for global greening through large-scale vegetation restoration in recent two ***,the unique,fragile geological setting of carbonate rocks affects the sustainability of vegetation ***,we summarize and evaluate the impacts of the rock and soil compositions of karst landscapes on the types and quality of vegetation *** introduce the concept of“soil mass”and establish its relationship with aboveground vegetation biomass across varying degrees of rocky *** mineral nutrients and soil mass constrain the potential of vegetation carbon sequestration in karst *** enhance the sustainability of vegetation restoration and carbon sequestration under karst geological constraints,we suggest to push ecological intensification of tree plantations and optimize the zoning and classification of rocky desertification treatment,and these restoration initiatives will foster vegetation restoration to serve as a pivotal pathway towards carbon neutrality.

关键词： soil karst Restoration

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