Methods of the comprehensive evaluation have been studied for many years. However, the change speed of evaluated objects was rarely considered by the existing evaluation methods. An evaluation matrix is proposed to re...Methods of the comprehensive evaluation have been studied for many years. However, the change speed of evaluated objects was rarely considered by the existing evaluation methods. An evaluation matrix is proposed to remedy this deficiency. Firstly, the change speed state （CSS） of the evaluated objects is analyzed based on double inspiriting control lines （DICLs）, and a matrix of the CSS is constructed. Then, 72 elements in the matrix are analyzed, and formulas describing each CSS are given. The efficiency of the proposed evaluation matrix is proved when the CSS merges with the change speed trend （CST） in the dynamic comprehensive evaluation. Finally, a computing example shows that the proposed evaluation matrix is feasible in the dynamic comprehensive evaluation with the speed feature.展开更多
The Sb6 Te4/VO2 multilayer thin films are prepared by magnetron sputtering and the potential application in phase change memory is investigated in detail. Compared with Sb6 Te4, Sb6 Te4/VO2 multilayer composite thin f...The Sb6 Te4/VO2 multilayer thin films are prepared by magnetron sputtering and the potential application in phase change memory is investigated in detail. Compared with Sb6 Te4, Sb6 Te4/VO2 multilayer composite thin films have higher phase change temperature and crystallization resistance, indicating better thermal stability and less power consumption. Also, Sb6 Te4/VO2 has a broader energy band of 1.58 eV and better data retention （125℃ for 103/）. The crystallization is suppressed by the multilayer interfaces in Sbf Te4/VO2 thin film with a smaller rms surface roughness for Sbf Te4/VO2 than monolayer Sb4Te6. The picosecond laser technology is applied to study the phase change speed. A short crystallization time of 5.21 ns is realized for the Sb6Te4 （2nm）/VO2 （8nm） thin film. The Sb6 Te4/VO2 multilayer thin film is a potential and competitive phase change material for its good thermal stability and fast phase change speed.展开更多
Land use dynamics is a prerequisite for identifying natural resource management constraints,the evolution of agrarian practices and population growth.The objective of this research is to improve knowledge of the dynam...Land use dynamics is a prerequisite for identifying natural resource management constraints,the evolution of agrarian practices and population growth.The objective of this research is to improve knowledge of the dynamics of agricultural land use in the dryland(Cinzana)and cotton(Kléla)areas of Mali.The methodology used consisted of planimetric data collection and diachronic analysis using Landsat TM(Thematic Mapper)satellite images from 2000 and OLI(Operational Land Image)from 2020.Degradation and deforestation rates of natural formations were calculated on the one hand,and on the other hand,the speed and intensity of changes were evaluated using the Pontius matrix22 and intensity analysis programs from the transition matrix.The results of the diachronic analysis revealed a clear increase in the area of anthropogenic formations,especially fields and fallow land,at the expense of natural formations.In Cinzana,this was reflected in an overall increase in the area of anthropogenic formations of 45%(i.e.,2.30%per year)and an overall reduction of 45.15%(2.26%per year)in the area of natural units.In Kléla,there was an overall increase of 131%(i.e.,6.54%per year)in the area of fields and fallow land to the detriment of natural formations,which underwent a reduction of 95%(i.e.,4.76%per year)between 2000 and 2020.Definitely,the evolution of landscape units in the research area between 2000 and 2020 points to excessive anthropization of natural formations,which could compromise the sustainability of these formations,with a risk to ecosystem services and agricultural productivity lost.The study recommends the use of agro-ecological practices,and the facilitation of access to agricultural technologies and support services with a view to agricultural intensification.Policy measures to promote an agro-ecological transition should be encouraged.展开更多
Gives a dynamic mathematical model of a typical type of multiple discs hydroviscous drive device which has been proved to be correct through tests.Utilizing the method of root-locus analysis the dynamic performance of...Gives a dynamic mathematical model of a typical type of multiple discs hydroviscous drive device which has been proved to be correct through tests.Utilizing the method of root-locus analysis the dynamic performance of this device is studied according to the model.Theoretical analysis and test re- suits show that the dynamic performance of the object of study can be greatly improved by speed negative feedback.展开更多
Infrastructure systems play a fundamental role in reducing greenhouse gas(GHG)emissions to avert global climate change(Kennedy et al.,2014).Transportations are recognized as one of the key factors for facilitating cli...Infrastructure systems play a fundamental role in reducing greenhouse gas(GHG)emissions to avert global climate change(Kennedy et al.,2014).Transportations are recognized as one of the key factors for facilitating climate change mitigation(Shaw et al.,2014).Approximately 19%of global energy consumption and 23%of energy-related carbon dioxide(CO2)emissions come from the transportation sector(IEA,2012).The demands are still increasing at an annual average rate of 1.4%(EIA,2016).Scholars展开更多
基金supported by the National Natural Science Foundation of China (7127217671302028)+1 种基金the Fundamental Scientific Research Funds for the Central Universities (HEUCF110914)the Heilongjiang Postdoctoral Fund (3236310094)
文摘Methods of the comprehensive evaluation have been studied for many years. However, the change speed of evaluated objects was rarely considered by the existing evaluation methods. An evaluation matrix is proposed to remedy this deficiency. Firstly, the change speed state （CSS） of the evaluated objects is analyzed based on double inspiriting control lines （DICLs）, and a matrix of the CSS is constructed. Then, 72 elements in the matrix are analyzed, and formulas describing each CSS are given. The efficiency of the proposed evaluation matrix is proved when the CSS merges with the change speed trend （CST） in the dynamic comprehensive evaluation. Finally, a computing example shows that the proposed evaluation matrix is feasible in the dynamic comprehensive evaluation with the speed feature.
基金Supported by the National Natural Science Foundation of China under Grant No 11774438the Natural Science Foundation of Jiangsu Province under Grant No BK20151172+2 种基金the Qing Lan Project,the Opening Project of State Key Laboratory of Silicon Materials under Grant No SKL2017-04the Opening Project of Key Laboratory of Microelectronic Devices and Integrated Technology of Chinese Academy of Sciencesthe Postgraduate Research and Practice Innovation Program of Jiangsu Province under Grant No SJCX18_1024
文摘The Sb6 Te4/VO2 multilayer thin films are prepared by magnetron sputtering and the potential application in phase change memory is investigated in detail. Compared with Sb6 Te4, Sb6 Te4/VO2 multilayer composite thin films have higher phase change temperature and crystallization resistance, indicating better thermal stability and less power consumption. Also, Sb6 Te4/VO2 has a broader energy band of 1.58 eV and better data retention （125℃ for 103/）. The crystallization is suppressed by the multilayer interfaces in Sbf Te4/VO2 thin film with a smaller rms surface roughness for Sbf Te4/VO2 than monolayer Sb4Te6. The picosecond laser technology is applied to study the phase change speed. A short crystallization time of 5.21 ns is realized for the Sb6Te4 （2nm）/VO2 （8nm） thin film. The Sb6 Te4/VO2 multilayer thin film is a potential and competitive phase change material for its good thermal stability and fast phase change speed.
文摘Land use dynamics is a prerequisite for identifying natural resource management constraints,the evolution of agrarian practices and population growth.The objective of this research is to improve knowledge of the dynamics of agricultural land use in the dryland(Cinzana)and cotton(Kléla)areas of Mali.The methodology used consisted of planimetric data collection and diachronic analysis using Landsat TM(Thematic Mapper)satellite images from 2000 and OLI(Operational Land Image)from 2020.Degradation and deforestation rates of natural formations were calculated on the one hand,and on the other hand,the speed and intensity of changes were evaluated using the Pontius matrix22 and intensity analysis programs from the transition matrix.The results of the diachronic analysis revealed a clear increase in the area of anthropogenic formations,especially fields and fallow land,at the expense of natural formations.In Cinzana,this was reflected in an overall increase in the area of anthropogenic formations of 45%(i.e.,2.30%per year)and an overall reduction of 45.15%(2.26%per year)in the area of natural units.In Kléla,there was an overall increase of 131%(i.e.,6.54%per year)in the area of fields and fallow land to the detriment of natural formations,which underwent a reduction of 95%(i.e.,4.76%per year)between 2000 and 2020.Definitely,the evolution of landscape units in the research area between 2000 and 2020 points to excessive anthropization of natural formations,which could compromise the sustainability of these formations,with a risk to ecosystem services and agricultural productivity lost.The study recommends the use of agro-ecological practices,and the facilitation of access to agricultural technologies and support services with a view to agricultural intensification.Policy measures to promote an agro-ecological transition should be encouraged.
文摘Gives a dynamic mathematical model of a typical type of multiple discs hydroviscous drive device which has been proved to be correct through tests.Utilizing the method of root-locus analysis the dynamic performance of this device is studied according to the model.Theoretical analysis and test re- suits show that the dynamic performance of the object of study can be greatly improved by speed negative feedback.
基金supported by the National Natural Science Foundation of China (Grant No.71390525)
文摘Infrastructure systems play a fundamental role in reducing greenhouse gas(GHG)emissions to avert global climate change(Kennedy et al.,2014).Transportations are recognized as one of the key factors for facilitating climate change mitigation(Shaw et al.,2014).Approximately 19%of global energy consumption and 23%of energy-related carbon dioxide(CO2)emissions come from the transportation sector(IEA,2012).The demands are still increasing at an annual average rate of 1.4%(EIA,2016).Scholars
