期刊文献+
共找到7篇文章
< 1 >
每页显示 20 50 100
Mining Weights of Land Evaluation Factors Based on Cloud Model and Correlation Analysis 被引量:17
1
作者 HU Shiyuan LI Deren +1 位作者 LIU Yaolin LI Deyi 《Geo-Spatial Information Science》 2007年第3期218-222,共5页
The veracity of land evaluation is tightly related to the reasonable weights of land evaluation fac- tors. By mapping qualitative linguistic words into a fine-changeable cloud drops and translating the uncertain facto... The veracity of land evaluation is tightly related to the reasonable weights of land evaluation fac- tors. By mapping qualitative linguistic words into a fine-changeable cloud drops and translating the uncertain factor conditions into quantitative values with the uncertain illation based on cloud model, and then, inte- grating correlation analysis, a new way of figuring out the weight of land evaluation factors is proposed. It may solve the limitations of the conventional ways. 展开更多
关键词 cloud models correlation analysis land evaluation factor weight data mining
下载PDF
Relative importance of climate factors and human activities in impacting vegetation dynamics during 2000–2015 in the Otindag Sandy Land,northern China 被引量:11
2
作者 MA Wenyong WANG Xunming +1 位作者 ZHOU Na JIAO Linlin 《Journal of Arid Land》 SCIE CSCD 2017年第4期558-567,共10页
In recent years, there has been increasing research interests in differentiating the relative importance of climate factors and human activities in impacting vegetation dynamics. In this study, based on residual trend... In recent years, there has been increasing research interests in differentiating the relative importance of climate factors and human activities in impacting vegetation dynamics. In this study, based on residual trend method, we used MOD13A3(MODIS vegetation index product), MCD12Q1(MODIS land cover product) and meteorological datasets to differentiate the relative importance of climate factors and human activities in impacting vegetation dynamics during 2000–2015 in the Otindag Sandy Land, northern China. Results show that during the study period(2000–2015), the overall vegetation condition had improved in the Otindag Sandy Land. The driving forces of vegetation dynamics differed spatially in the whole study area over the study period. The area with vegetation degradation solely resulted from human activities accounted for 8.23% of the study area, while the area with vegetation degradation resulted from others(including climate factors and combination of climate factors and human activities) occupied 1.53%. The area with vegetation recovery benefitted from human activities occurred over 26.02% of the study area; the area benefitted from climate factors accounted for 23.69%; and the area benefitted from both climate factors and human activities occupied 37.74%. All in all, impacts of climate factors and human activities on vegetation dynamics varied at the county/city/banner scales and locality-specific measures should be adopted to protect the environments. 展开更多
关键词 vegetation NDVI climate factors human factors Otindag Sandy land
下载PDF
A Study on the Allocation of New Construction Land Use Indicators in Huai'an City
3
作者 Haiyan YANG Yuwei HUANG 《Asian Agricultural Research》 2017年第2期35-38,共4页
This paper makes a comprehensive analysis on the characteristics and influencing factors of regional allocation of new construction land use indicators,and determines the primary indicators from social,economic,extern... This paper makes a comprehensive analysis on the characteristics and influencing factors of regional allocation of new construction land use indicators,and determines the primary indicators from social,economic,external and internal factors.Using Delphi method and correlation analysis,this paper selects indicators and establishes evaluation indicator system.Using entropy method and AHP,this paper determines the weight of indicators,rationally allocates new construction land,and uses the actual data in Huai'an City for case studies,so as to provide a reference for land use planning.In addition,this paper makes a comparative analysis on the land use internal factors as important factors,in order to make the weight assigning more in line with the actual situation of construction land in Huai'an. 展开更多
关键词 New construction land use indicators ALLOCATION land use internal factors Comparative analysis
下载PDF
A Modified DRASTIC Approach to Shallow Groundwater Vulnerability in the West Lake Watershed in Hangzhou, China 被引量:4
4
作者 DONG LIANG, ZHU YINMEI and N. OGURA Department of Environmental Science, Zhejiang University, Hangzhou 310029 (China) The United Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509 (Japan) 《Pedosphere》 SCIE CAS CSCD 2002年第1期73-80,共8页
The quality of shallow groundwater in the West Lake watershed wasinvestigated form March to July 2000. Integrating with BlacklandGRASS GIS system, the DRASTIC model was used to compile the ground-water vulnerability m... The quality of shallow groundwater in the West Lake watershed wasinvestigated form March to July 2000. Integrating with BlacklandGRASS GIS system, the DRASTIC model was used to compile the ground-water vulnerability map. A land use factor was added to the DRASTICmodel and the modified model (LDRASTIC0 increased the accuracy ofprediction form 26.9/100 to 51.3/100. The vulnerability map showedthat the lowly, moderately and highly susceptible area predictedoccupied about 11.6/100, 70.9/100 and 17.5/100 of the wholewatershed, respectively. Compared with the observed values of nitrateand electric conductivity, the LDRASTIC index improved the Pearsoncorrelation coefficients form -0.010 to 0.237 and 0.380 to 0.503;Both the improved coefficients were significant at the 0.01 level.The modified DRASTIC analysis showed a Great potential as a screeningtool for policy decision-making in groundwater management. 展开更多
关键词 DRASTIC GIS land use factor shallow groundwater
下载PDF
Free radicals, apparent activation energy, and functional groups during low-temperature oxidation of Jurassic coal in Northern Shaanxi 被引量:2
5
作者 Wang Caiping Xiao Yang +2 位作者 Li Qingwei Deng Jun Wang Kai 《International Journal of Mining Science and Technology》 EI CSCD 2018年第3期469-475,共7页
Correlations among free radicals, apparent activation energy, and functional groups during lowtemperature oxidation of Jurassic coal in Northern Shaanxi were investigated by examining three coal samples collected from... Correlations among free radicals, apparent activation energy, and functional groups during lowtemperature oxidation of Jurassic coal in Northern Shaanxi were investigated by examining three coal samples collected from the Ningtiaota, Jianxin, and Shigetai coal mines. Free radical concentrations at less than 120 ℃ were investigated by electron spin resonance experiments while the thermogravimetric experiments were conducted to analyze apparent activation energies. In addition, Fourier transform infrared spectroscopy was employed to study the spectrum of functional groups generated in coal. The results indicated that, in decreasing order, the apparent activation energies were Shigetai 〉Jianxin 〉 Ningtiaota, indicating that, from 50 to 120 ℃, the Ningtiaota coal sample most easily absorbed and reacted with oxygen while the most resistant was the Shigetai coal sample. Free radical concentrations and line heights increased with increased temperature, and the line width and Lande factor showed irregular fluctuations. Functional group variations were different among these coals, and the phenol and alcohol-associated OHs, carboxyls, and aromatic ring double bonds might have had a major impact on free radical concentrations. These results were meaningful for better consideration and management of coal oxidation at low temperatures. 展开更多
关键词 Free racial concentration Functional groups Low-temperature oxidation lande factor Apparent activation energy
下载PDF
A New Method Based on Association Rules Mining and Geo-filter for Mining Spatial Association Knowledge 被引量:6
6
作者 LIU Yaolin XIE Peng +3 位作者 HE Qingsong ZHAO Xiang WEI Xiaojian TAN Ronghui 《Chinese Geographical Science》 SCIE CSCD 2017年第3期389-401,共13页
Association rule mining methods, as a set of important data mining tools, could be used for mining spatial association rules of spatial data. However, applications of these methods are limited for mining results conta... Association rule mining methods, as a set of important data mining tools, could be used for mining spatial association rules of spatial data. However, applications of these methods are limited for mining results containing large number of redundant rules. In this paper, a new method named Geo-Filtered Association Rules Mining(GFARM) is proposed to effectively eliminate the redundant rules. An application of GFARM is performed as a case study in which association rules are discovered between building land distribution and potential driving factors in Wuhan, China from 1995 to 2015. Ten sets of regular sampling grids with different sizes are used for detecting the influence of multi-scales on GFARM. Results show that the proposed method can filter 50%–70% of redundant rules. GFARM is also successful in discovering spatial association pattern between building land distribution and driving factors. 展开更多
关键词 data mining association rules rules spatial visualization driving factors analysis land use change
下载PDF
Thermodynamic properties of two-dimensional charged spin-1/2 Fermi gases
7
作者 Jia-Ying Yang Xu Liu +1 位作者 Ji-Hong Qin Huai-Ming Guo 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第6期254-259,共6页
Based on the mean-field theory,we investigate the thermodynamic properties of the two-dimensional(2D)charged spin-1/2 Fermi gas.Lande′factor g is introduced to measure the strength of the paramagnetic effect.There is... Based on the mean-field theory,we investigate the thermodynamic properties of the two-dimensional(2D)charged spin-1/2 Fermi gas.Lande′factor g is introduced to measure the strength of the paramagnetic effect.There is a competition between diamagnetism and paramagnetism in the system.The larger the Lande′factor,the smaller the entropy and specific heat.Diamagnetism tends to increase the entropy,while paramagnetism leads to the decrease of the entropy.We find that there exists a critical value of Lande′factor for the transition point due to the competition.The entropy of the system increases with the magnetic field when g<0.58.With the growth of paramagnetism,when g>0.58,the entropy first decreases with the magnetic field,then reaches a minimum value,and finally increases again.Both the entropy and specific heat increase with the temperature,and no phase transition occurs.The specific heat tends to a constant value at the hightemperature limit,and it approaches to zero at very low temperatures,which have been proved by the analytical calculation. 展开更多
关键词 Fermi gas ENTROPY specific heat landéfactor
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部