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A Characterization of PSL(2,q),q=5,7

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Algebra Colloquium 2019年第4期26卷 561-564页

作者： Marius Tarnauceanu jiping zhang Faculty of Mathematics UA1.I.Cuza”UniversityIasiRomania 不详

In this short note we prove that the finite non-abelian simple groups PSL(2,q),where g=5,7,are determincd by their posets of classes of isomorphic *** interesting open problems are also formulated.

关键词： simple groups solvable groups posets of isomorphic subgroups

Improved sea-ice radiative processes in a global coupled climate model

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Acta Oceanologica Sinica 2005年第6期24卷 68-79页

作者： LIU jiping zhang Zhanhai WU Huiding School of Earth & Atmospheric Sciences Georgia Institute of Technology Atlanta Georgia 30332 USA State Oceanic Administration Key Laboraory for Polar Science Polar Research Institute of China Shanghai 200129 China State Oceanic Administration Key Laboraory for Polar Science Polar Research Institute of China Shanghai 200129 China State Oceanic Administration Key Laboraory for Polar Science Polar Research Institute of China Shanghai 200129 China National Marine Environmental Forecast Center Beijing 100081 China

The NASA Goddard Institute for Space Studies (GISS) coupled global climatemodel was used to investigate the sensitivity of sea ice to improved representations of sea-iceradiative processes: (1) a more sophisticated surface albedo scheme and (2) the penetration of solarradiation in sea ice. The results show that the large-scale sea-ice conditions are very sensitiveto the aforementioned parameteriza-tions. Although the more sophisticated surface albedo schemeproduces a more realistic seasonal cycle of the surface albedo as compared with the baselinesimulation, the resulting higher albedo relative to the baseline simulation generates much more andthicker ice in the arctic. The penetration of solar radiation in sea-ice itself tends to reduce theice cover and thickness in the entire arctic and the western antarctic, and increase the ice coverand thickness in the eastern antarctic. The combination of (1) and (2) significantly improves thesimulations of the average ice thickness and its spatial distribution in the arctic. The atmosphericresponses associated with sea-ice changes were also discussed. While improvements are seen,particularly of the ice thickness distribution, there are still some unrealistic aspects that willrequire further improvements to the sea-ice component.

关键词： sea ice GISS coupled model surface albedo penetration of solar radiation arctic and antarctic

Derived norms of finite groups

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Science China Mathematics 2022年第12期65卷 2493-2502页

作者： Zhencai Shen Shirong Li jiping zhang College of Science China Agricultural UniversityBeijing100183China Department of Mathematics Guangxi UniversityNanning 530004China LMAM and School of Mathematical Sciences Peking UniversityBeijing 100871China

The intersection of particular subgroups is a kind of interesting substructure in group theory. Let G be a finite group and D(G) be the intersection of the normalizers of the derived subgroups of all the subgroups of G. A group G is called a D-group if G = D(G). In this paper, we determine the nilpotency class of the nilpotent residual G^(N) and investigate the structure of D(G) by a new concept called the IO-D-group. A non-D-group G is called an IO-D-group(inner-outer-D-group) if all of its proper subgroups and proper quotient groups are D-groups. The structure of IO-D-groups are described in detail in this paper. As an application of the classification of IO-D-groups, we prove that G is a D-group if and only if any subgroup of G generated by3 elements is a D-group.

关键词： derived subgroups D-groups nilpotent residuals IO-D-groups

Modified graphene as novel lubricating additive with high dispersion stability in oil

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Friction 2021年第1期9卷 143-154页

作者： Pu WU Xinchun CHEN Chenhui zhang jiping zhang Jianbin LUO Jiyang zhang State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China Tianjin Research Institute for Advanced Equipment Tsinghua UniversityTianjin 300300China Beijing Key Laboratory of Long-life Technology of Precise Rotation and Transmission Mechanisms Beijing Institute of Control EngineeringBeijing 100094China

Graphene is a promising material as a lubricant additive for reducing friction and ***,a dispersing method which combines chemical modification of graphene by octadecylamine and dicyclohexylcarbodiimide with a kind of effective dispersant has been successfully developed to achieve the remarkable dispersion stability of graphene in base *** stable dispersion time of modified graphene(0.5 wt%)with dispersant(1 wt%)in PAO-6 could be up to about 120 days,which was the longest time reported so *** the same time,the lubricant exhibits a significant improvement of tribological performance for a steel ball to plate tribo-system with a normal load of 2 *** coefficient of friction between sliding surfaces was~0.10 and the depth of wear track on plate was~21 nm,which decreased by about 44%and 90%when compared to pure PAO-6,***,the analysis of the lubricating mechanisms in regard to the sliding-induced formation of nanostructured tribo-film has been contacted by using Raman spectra and TEM.

关键词： modified graphene dispersity lubricant additives tribo-film

Predicting Potential Distribution of Tibetan Spruce (Picea smithiana) in Qomolangma (Mount Everest) National Nature Preserve Using Maximum Entropy Niche-based Model

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Chinese Geographical Science 2011年第4期21卷 417-426页

作者： zhang jiping zhang Yili LIU Linshan NIE Yong Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China Graduate University of Chinese Academy of Sciences Beijing 100049China Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China

Tibetan spruce (Picea smithiana) is an endemic species of the Himalayas,and it distributes only in a re-stricted area with very low *** address the lack of detailed distributional information,we used maximum en-tropy (Maxent) niche-based model to predict the species' potential distribution from limited occurrence-only *** location data of ***,relative bioclimatic variables,vegetation data,digital elevation model (DEM),and the derived data were analyzed in *** receiver operating characteristic (ROC) curve was applied to assess the prediction *** Maxent jackknife test was performed to quantify the training gains from data layers and the response of *** distribution to four typical environmental variables was *** show that the model performs well at the regional *** is a potential for continued expansion of *** population numbers and distribution in *** potentially distributes in the lower reaches of Gyirong Zangbo and Poiqu rivers in Gyirong and Nyalam counties in Qomolangma (Mount Everest) National Nature Preserve (QNNP),*** species prefers warm temperate climate in mountain area and mainly distributes in needle-leaved evergreen closed to open forest and mixed forest along the river valley at relatively low altitudes of about 2000-3000 *** simulations suggest that distribution patterns of rare species with few species numbers can be well predicted by Max-ent.

关键词： Picea smithiana maximum entropy niche-based model potential distribution Qomolangma (Mount Ev-erest) National Nature Preserve (QNNP)

Impact of livelihood diversification of rural households on their ecological footprint in agro-pastoral areas of northern China

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Journal of Arid Land 2015年第5期7卷 653-664页

作者： HAO Haiguang zhang jiping LI Xiubin zhang Huiyuan zhang Qiang Chinese Research Academy of Environmental Sciences Beijing Municipal Research Institute of Environmental Protection Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences

Human-environment relationship is a focus of academic researches and an understanding of the rela- tionship is important for making effective policies and decisions. In this study, based on rural household survey data of Taibus Banner, Duolun county and Zhengxiangbai Banner in the Inner Mongolia autonomous region of China, we identified the impact of livelihood diversification on ecosystems in these agro-pastoral areas by using the ecological footprint theory and methodology together with the one-way analysis of variance （ANOVA） and correlation analysis methods. In 2011, the total ecological footprint of consumption （EFC） was 0.665 g hm2, and the total ecological footprint of production （EFP） was 2.045 g hm2, which was more than three times the EFC. The ecological footprint of arable land consumption （EFAC） accounted for a large proportion of the EFC, and the ecological footprint of grassland production （EFGP） occupied a large proportion of the EFP. Both the ecological footprint of grassland consumption （EFGC） and EFGP had a significant positive correlation with the income, indicating that income was mainly depended on livestock production and the households with higher incomes consumed more livestock prod- ucts. The full-time farming households （FTFHs） had the highest EFP, ecological footprint of arable land production （EFAP）, EFGP and EFGC, followed by the part-time farming households （PTFHs） and non-farming households （NFHs）, which indicated that part-time farming and non-farming employment reduced the occupancy and con- sumption of rural households on local ecosystems and natural resources to some extent. When farming households engaged in livestock rearing, both the EFAP and EFAC became smaller, while the EFP, EFC, EFGC and EFGP increased significantly. The differences in ecological footprints among different household groups should be taken into account when making ecosystem conservation policies. Encouraging the laborers who have the advantages of participati

关键词： ecological footprint livelihood diversification livestock rearing non-farming employment rural households agro-pastoral area

Agricultural land use intensity study in Taibus Banner, and its determinants： a case Inner Mongolia, China

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Frontiers of Earth Science 2015年第2期9卷 308-318页

作者： Haiguang HAO Xiubin LI Minghong TAN jiping zhang Huiyuan zhang Chinese Research Academy of Environmental Sciences Beijing 100012 China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Beijing Municipal Research Institute of Environmental Protection Beijing 100037 China

Based on rural household survey data from Taibus Banner, in the Inner Mongolia Autonomous Region, China, this study separately categorizes agricul- tural land use intensity into labor intensity, capital intensity, the intensity of labor-saving inputs, and the intensity of yield-increasing inputs, and then analyzes their determinants at the household level. The findings reveal that within the study area：（1） labor intensity is higher and capital intensity is lower than in the major grain-producing and economically developed areas of eastern and central China; （2） the most widely planted crops are those with the lowest labor intensity （oats） and capital intensity （benne）; （3） there are marked differences in agricultural land use intensity among households; a major factor affecting land use decision-making is the reduced need for labor intensity for those households with high opportunity costs, such as those with income earned from non-farming activities which alleviates financial constraints and allows for increased capital intensity. As a result, these households invest more in labor-saving inputs; （4） households with a larger number of workers will allocate adequate time to manage their land and thus they will not necessarily invest more in labor-saving inputs. Those households with more land to manage tend to adopt an extensive cultivation strategy. Total income has a positive impact on capital intensity and a negative impact on labor intensity. House- holds that derive a higher proportion of their total income through farming are more reliant upon agriculture, which necessitates significant labor and yield-increasing inputs. Finally, the authors contend that policy makers should clearly recognize the impacts of non-farming employment on agricultural land use intensity. In order to ensure long- term food security and sustainable agricultural develop-ment in China, income streams from both farming and non- farming employment should be balanced.

关键词： agricultural land use intensity labor intensity,capital intensity opportunity cost of farm workers TaibusBanner

Carbon storage of a subtropical forest ecosystem: a case study of the Jinggang Mountain National Nature Reserve in south-eastern China

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Journal of Forestry Research 2019年第3期30卷 1011-1021页

作者： jiping zhang Linbo zhang Haiguang Hao Chunlan Liu Hui Wang Beijing Municipal Research Institute of Environmental Protection Beijing 100037People’s Republic of China Chinese Research Academy of Environmental Sciences Beijing 100012People’s Republic of China

The carbon cycle of forest ecosystems plays a key role in regulating CO2 concentrations in the atmosphere. Research on carbon storage estimation of forest ecosystems has become a major research topic. However, carbon budgets of subtropical forest ecosystems have received little attention. Reports of soil carbon storage and topographic heterogeneity of carbon storage are limited. This study focused on the Jinggang Mountain National Nature Reserve as an example of a mid-subtropical forest and evaluated soil and vegetation carbon storage by field sampling combined with GIS, RS and GPS technology. We classified the forest into nine forest types using ALOS high-resolution remote sensing images. The evergreen broad-leaved forest has the largest area, occupying 26.5% of the total area, followed by coniferous and broad-leaved mixed forests and warm temperate coniferous forest, occupying 24.2 and 22.9%, respectively. The vegetation and soil carbon storage of the whole forest ecosystem were 1,692,344 and 5,514,707 t, with a carbon density of 7.4 and 24.2 kg/m^2, respectively, which suggests that the ecosystem has great carbon storage capacity. The topographic heterogeneity of the carbon storage was also analysed. The largest vegetation storage and soil storage is at 700–800 and 1000–1100 m, respectively. The vegetation carbon storage is highest in the southeast, south and southwest.

关键词： Vegetation carbon storage Soil carbon storage Mid-subtropical forest ecosystem Jinggang Mountain National Nature Reserve

Homology and Cohomology of the Super Schrodinger Algebra 5(1/1)with Coefficients in the Trivial Module

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Algebra Colloquium 2019年第4期26卷 615-628页

作者： Yan He Yuezhu Wu Linsheng Zhu jiping zhang School of Mathematical Sciences Soochow UniversitySuzhouJiangsu 215006China School of Mathematics and.Statistics Changshu Institute of Technology ChangshuJiangsu 215500China School of Mathematical Sciences Jiangsu University of Technology ChangzhouJiangsu 213000China 不详

In this paper we study the homology and cohomology groups of the super Schrodinger algebra S(1/1)in(1+l)-dimensional *** explicitly compute the homology groups of S(1/1)with coefficients in the trivial *** using duali... 详细信息

关键词： super Schrodinger algebra homology cohomology