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spatial heterogeneity in liquid–liquid phase transition

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Chinese Physics B 2017年第3期26卷 418-425页

作者：段云瑞李涛吴维康李洁周戌燕刘思达李辉 Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials of Ministry of Education Shandong University Jinan 250061 China

Molecular dynamics simulations are performed to investigate the liquid-liquid phase transition （LLPT） and the spatial heterogeneity in A1-Pb monotectic alloys. The results reveal that homogeneous liquid AI-Pb alloy undergoes an LLPT, separating into Al-rich and Pb-rich domains, which is quite different from the isocompositional liquid water with a transition between low-density liquid （LDL） and high-density liquid （HDL）. With spatial heterogeneity becoming large, LLPT takes place correspondingly. The relationship between the cooling rate, relaxation temperature and percentage of A1 and the spatial heterogeneity is also reported. This study may throw light on the relationship between the structure heterogeneity and LLPT, which provides novel strategies to control the microstructures in the fabrication of the material with high performance.

关键词： spatial heterogeneity liquid-liquid phase transition phase separation

spatial heterogeneity of Marine Environment Changes:A Case Study in Laizhou Bay and Its Adjacent Waters,China

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Journal of Ocean University of China 2021年第1期20卷 111-123页

作者： WANG Youxiao YU Ge HU Guobin LIU Dahai College of Environmental Science and Engineering Ocean University of ChinaQingdao 266100China Key Laboratory of Marine Environment and Ecology Ministry of EducationQingdao 266100China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China College of Marine Life Sciences Ocean University of ChinaQingdao 266003China First Institute of Oceanography Ministry of Natural ResourcesQingdao 266061China

Temporal and spatial heterogeneity identifications of marine environment and its changes have great significances in marine spatial planning and offshore pollution *** this study,considering the integration of marine ecological environment and sea-land interaction,we built a spatialized evaluation model named Marine Environment Change spatial Assessment(MECSA)to quantify the marine environment status and *** MECSA,we applied the geospatial model and the pressure-state-response(PSR)model for processing and integrating evaluation indicators.A case study in the Laizhou Bay showed that the marine environment quality was generally in a declining state from 2009 to *** 2015,the Marine Environment Index(MEI)had decreased by 0.1 compared with 2009,although the two years all reached a‘Good'*** spatial MEI layers of the two years showed a same distribution:the southwestern part was in poorer status,with a fan ring shape gradually getting better to the *** Marine Organisms Response Index(MORI)contributed the most to the ***,future marine environmental assessment and spatial planning should focus on the identification the marine environment with its changes from the perspective of spatial heterogeneity and *** on single indicators and comprehensive evaluation results,we can propose spatially targeted policies and recommendations scientifically.

关键词： marine environment quality spatial heterogeneity PSR Laizhou Bay

spatial heterogeneity of dead fuel moisture content in a Larix gmelinii forest in Inner Mongolia using geostatistics

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Journal of Forestry Research 2021年第2期32卷 569-577页

作者： Heng Zhang Shihao Ma Ping Kang Qiuliang Zhang Zhiwei Wu Forestry College of Inner Mongolia Agricultural UniversityHohhot 010019People’s Republic of China Key Laboratory of Poyang Lake Wetland and Watershed Research Ministry of EducationJiangxi Normal UniversityNanchang 330022People’s Republic of China

spatial heterogeneity of fuel moisture content determines the spread rate and direction of a forest *** on the spatial heterogeneity of the moisture content of dead fuel of Larix gmelinii *** that:(1)fuel moisture content in litter layerspatial heterogeneity of the semi-humus layer was the *** humus layer in the slant direction and three layers in a vertical direction showed strong spatial correlation with the lowest nugget coefficient of 0.0968;(3)the fuel moisture content of the humus layer showed strong spatial anisotropy;and,(4)estimating the total moisture content of the sampling site by stimulated sampling reasonable control of the sampling interval,and increasing the sampling intensity can reduce the *** the sampling intensity is increased to more than 16 and the sampling interval 3 m,the standard error isspatial heterogeneity of fuel moisture content is best revealed by increasing sampling density,sampling in different fire seasons,and in different slope directions and *** results can provide a scientific basis for forest fire prediction and prevention.

关键词： Forest combustibles spatial heterogeneity Analog sampling Standard error

spatial heterogeneity and Influencing Factors of HFRS Epidemics in Rural and Urban Areas:A Study in Guanzhong Plain of Shaanxi Province,China

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Biomedical and Environmental Sciences 2022年第11期35卷 1012-1024页

作者： ZHU Ling Li LI Yan Ping LU Liang LI Shu Juan REN Hong Yan National Institute for Nutrition and Health Chinese Center for Disease Control and PreventionBeijing 100050China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Xi’an Eighth Hospital Xi’an 710061ShaanxiChina State Key Laboratory of Infectious Disease Prevention and Control National Institute for Communicable Disease Control and PreventionChinese Center for Disease Control and PreventionBeijing 102206China

Objective The Guanzhong Plain of Shaanxi Province is a severely afflicted hemorrhagic fever with renal syndrome(HFRS)epidemic area,while HFRS prevalence has decreased in most epidemic areas in *** information is available regarding the leading fine-scale influencing factors in this highly HFRSconcentrated area and the roles of natural environmental and socioeconomic *** investigate this,two regions in the Guanzhong Plain,that is,the Chang’an District and Hu County,with similar geographical environments,different levels of economic development,and high epidemic prevalence,were chosen as representative areas of the HFRS *** Maximum entropy models were constructed based on HFRS cases and fine-scale influencing factors,including meteorological,natural environmental,and socioeconomic factors,from 2014 to *** More than 95% of the HFRS cases in the study area were located in the northern plains,which has an altitude of less than 800 m,with topography contributed 84.1% of the impact on the spatial differentiation of the HFRS *** the northern plains,precipitation and population density jointly affected the spatial differentiation of the HFRS epidemic,with contribution rates of 60.7% and 28.0%,*** comparing the influencing factors of the northern plains of Chang’an District and Hu County,we found that precipitation and the normalized difference vegetation index(NDVI)dominated the HFRS epidemic in the relatively developed Chang’an District,while land-use type,temperature,precipitation and population density dominated the HFRS epidemic in the relatively undeveloped Hu *** Topography was the primary key factor for HFRS prevalence in the Chang’an District and Hu County,and the spatial differentiation of HFRS was dominated by precipitation and population density in the northern *** with the influencing factors of the relatively developed Chang’an District,the developing Hu County was more affected

关键词： Hemorrhagic fever with renal syndrome(HFRS) spatial heterogeneity Influencing factors Economic development stages Fine scale Maximum Entropy model

spatial heterogeneity of Vegetation in China

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Tsinghua Science and Technology 2007年第4期12卷 424-434页

作者：黄大明王昱生 Masae Shiyomi 柳小妮宋百敏陈俊 Shigeo Takahashi Yoshimichi Hori Yasuo Yamamura Ecology Research Station Department of Biological Sciences and Biotechnology Tsinghua University Grassland Research Station College of Animal Science and Technology Northeast Agricultural University Faculty of Science Ibaraki University Bunkyo 2-1-1 Mito 310-8512 Japan National Institute of Livestock and Grassland Science 768 Senbonmatsu Nishinasuno Tochigi 329-2793 Japan

The spatial heterogeneity and ecological characteristics of 74 vegetation types and the lack of vegetation type within the 9.6 million km2 of Chinese territory were studied using data from the China vegetation map. The analysis used 877 large quadrats 10 mm×10 mm （actual size 100 km×100 km）, which covered about 8.77 million km^2. Each large-quadrat was divided into four small 5 mm×5mm quadrats （actual size 50 km×50 km）. The frequency of occurrence of all vegetation types was recorded in each small quadrat. The survey using the Shiyomi method of vegetation analysis based on the beta-binomial distribution was adopted to describe the frequency of occurrence and spatial heterogeneity for each kind of vegetation. The weighted average heterogeneity of all the vegetation types in the landscape provides a measure of the landscape level heterogeneity which describes the spatial intricacy of the existing vegetation composition. The maximum spatial vegetation heterogeneity was 0.8620 in the frigid-temperate coniferous forest of Larix （V1）, which dominates cold moist northeast China. The minimum spatial heterogeneity with a low occurrence was the Caragana tibetica in the gravel desert in the western Yellow River Hetao area. The minimum occurrence with a low spatial heterogeneity was the Monsoon rainforest on rock in Guangxi and Yunnan Provinces. The vegetation types on the Qing-Zang Plateau were found to be representative of Chinese vegetation because of the very high occurrence and spatial heterogeneity of these vegetation types. The weighted average of the heterogeneity was 0.677, while the vegetation diversity index was 3.29.

关键词： spatial heterogeneity beta-binomial distribution ecosystem evaluation Chinese vegetation

spatial heterogeneity of soil chemical properties between Haloxylon persicum and Haloxylon ammodendron populations

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Journal of Arid Land 2010年第4期2卷 257-265页

作者： Li, CongJuan Li, Yan Ma, Jian Fan, LianLian Wang, QinXue Chinese Acad Sci Xinjiang Inst Ecol & Geog Fukang Stn Desert Ecol Urumqi 830011 Peoples R China Chinese Acad Sci Grad Univ Beijing 100049 Peoples R China Natl Inst Environm Studies Tsukuba Ibaraki 3058506 Japan

spatial heterogeneity is a ubiquitous feature in natural ecosystems, especially in arid regions. Different species and their discontinuous distribution, accompanied by varied topographic characteristics, result in soil resources distributed differently in different locations, and present significant spatial heterogeneity in desert ecosystems. In this study, conventional and geostatistical methods were used to identify the heterogeneity of soil chemical properties in two desert populations, Haloxylon persicum Bunge ex Boss., which dominates on the slopes and tops of sand dunes and Haloxylon ammodendron (C. A. Mey.) Bunge, which inhabits interdunes in the Gurbantunggut Desert of Xinjiang, China. The results showed that soil pH, electrical conductivity (EC), soil organic carbon (SOC), available nitrogen (AN) and available phosphorus (AP) were significantly higher in H. ammodendron populations than that in H. persicum. The coefficient of variation (CV) indicated that (1) most parameters presented a moderate degree of variability (10% spatial dependence (C0/(C0+C) spatial distribution was correlated with the vegetation distribution, individual size of plants, and the topographic features, especially with the plants nearest to sampling points and the topographic features. In each plot, soil EC, SOC, AN and AP presented similar distributions, and fertile islands and salt islands occurred in both plots but did not affect every individual plant, since the sampling distance was larger than the size of such fertile islands. The results of topogr

关键词： fertile island geostatistics plant population soil chemical properties spatial heterogeneity

spatial heterogeneity and Variability of a Large-Scale Vegetation Community Using a Power-Law Model

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Tsinghua Science and Technology 2005年第4期10卷 469-477页

作者：宋志远黄大明 SHIYOMI Masae 王昱生 TAKAHASHI Shigeo YOSHIMICHI Hori YAMAMURU Yasuo 陈俊 Department of Biological Sciences and Biotechnology Tsinghua University Beijing 100084 China Faculty of Science Ibaraki University Bunkyo 2-1-1 Mito 310-8512 Japan College of Animal Science Northeast Agricultural University Harbin 150030 China National Institute of Livestock and Grassland Science 768 Senbonmatsu Nishinasuno Tochigi 329-2793 Japan

spatial heterogeneity and stability are fundamental indices for describing vegetation communities. The spatial distribution characteristics of the vegetation in Nenjiang region of northeastern China were evaluated using a variance power-law model. The data fits the model well with estimates given for the levels of heterogeneity for not only single species but also the community as a whole. The linear regression indicates that the species in the community exhibit a consistently organized spatial pattern, as is often discovered in field surveys but rarely seen in artificial systems. The species deviations from the regression line, which exhibit a leptokurtic distribution, may reflect the variability of the community. Thus, the model provides a general tool for management and regulation of ecosystems, especially where there is human disturbances.

关键词： power-law model spatial heterogeneity community variability leptokurtic distribution resilience

spatial heterogeneity of available zinc, copper, and manganese in Xiangcheng Tobacco Planting Fields, Henan Province, China

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Frontiers in Biology 2009年第4期4卷 469-476页

作者： Haisheng CHEN Zili SHEN Guoshun LIU Zhengxian TONG Zhejiang Tongji Vocational College of Science and Technology Hangzhou 311231China College of Life Science Henan UniversityKaifeng 475001China National Tobacco Cultivation Physiology and Biochemistry Research CenterHenan Agricultural UniversityZhengzhou 450002China

Geostatistical methods were used in combina-tion with geographical information system(GIS)technol-ogy to analyze the spatial distribution characteristics of available zinc,copper,and manganese in the Xiangcheng tobacco planting fields,Henan province,*** of the isotropic variogram indicated that the Zn semivar-iogram was well described with the Gaussian model,with the distance of spatial dependence being 900.7m;while the Mn semivariogram was well described with spherical models,with the distance of spatial dependence being 14060m;and,the Cu semivariogram was well described with exponential models,with the distance of spatial dependence being *** and Zn were strongly spatially dependent,with the C_(0)/sill being 0.014 and 0.147 in this given region;while Cu was moderately spatially dependent,with the C_(0)/sill being *** the kriging analysis,the spatial distribution maps of contents of these three trace elements in the Xiangcheng tobacco planting regions was drawn with the Arcview *** was found that the soils with higher content of Mn were mainly distributed in the high mountains of the southern part of the given regions,while the soils with higher content of Cu were mainly distributed in the south,decreasing from the south to the *** soil with contents of Zn in the range of 0.76–1.33 mg/kg existed in the high mountains of the west and middle parts of the investigated regions,accounting for 76.11%of the whole area.

关键词： geo-statistics spatial heterogeneity flue-cured tobacco trace elements

spatial heterogeneity of fine root biomass of Pinus massoniana forests in the Three Gorges Reservoir Area, China

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Forestry Studies in China 2013年第1期15卷 13-23页

作者： Rui-Li WANG Rui-Mei CHENG Wen-Fa XIAO Xiao-Hui FENG Ze-Bin LIU Xiao-Rong WANG Zhi-Bo WANG Key Laboratory of Forest Ecology and Environment of State Forestry Administration Research Institute of Forest Ecology Environment and Protection Chinese Academy of Forestry Center for Agricultural Resources Research Institute of Genetics and Developmental Biology Chinese Academy of Sciences Hubei Forestry Academy Research Institute of Forest Resource Information Techniques Chinese Academy of Forestry

Environmental heterogeneity is a constant presence in the natural world that significantly affects plant behavior at a variety of levels of complexity. In order to estimate the spatial pattern of fine root biomass in the Three Gorges Reservoir Area, the spatial heterogeneity of fine root biomass in the upper layer of soils （0-10 cm） in three Mas- son pine （Pinus massoniana） stands in the Three Gorges Reservoir Area, China, was studied in 30 m x 30 m plots with geostatistical analysis. The results indicate that 1） both the live and dead fine root biomass of stand 2 were less than those of other stands, 2） the spatial variation of fine roots in the three stands was caused together by structural and ran- dom factors with moderate spatial dependence and 3） the magnitude of spatial heterogeneity of live fine roots ranked as： stand 3 〉 stand 1 〉 stand 2, while that of dead fine roots was similar in the three stands. These findings suggested that the range of spatial autocorrelation for fine root biomass varied considerably in the Three Gorges Reservoir Area, while soil properties, such as soil bulk density, organic matter and total nitrogen, may exhibit great effect on the spatial distribution of fine roots. Finally, we express our hope to be able to carry out further research on the quantitative relation- ship between the spatial heterogeneous patterns of plant and soil properties.

关键词： spatial heterogeneity geostatistics Pinus massoniana fine root biomass Three Gorges Reservoir Area