The contemporary tectonic stress field in China is obtained on the basis of Chinese stress field database and Harvard CMT catalogue. Result of the inverted tectonic stresses shows that the maximum principal stress axi...The contemporary tectonic stress field in China is obtained on the basis of Chinese stress field database and Harvard CMT catalogue. Result of the inverted tectonic stresses shows that the maximum principal stress axis strikes nearly north-south direction in the west part of Tibet plateau, ENE direction in North China. In Central China, its strikes show a ra- diated pattern, i.e., NNE in north part and NNW in south part. The detailed stress field parameters of nearly whole China are given and can be used in geodynamic stress field simulation and earthquake prediction.展开更多
The mechanism of transport of chemicals in soil is an important research topic of environmental science and engineering, and some models and methods for a variety of solute transport problems have been done. Howeve...The mechanism of transport of chemicals in soil is an important research topic of environmental science and engineering, and some models and methods for a variety of solute transport problems have been done. However. most of previous works are usually for a soil column of infinite dimension. Starting from the one-dimension transient solute transport equation and its boundary and initial condition for a solute transport problem of soil column of finite length, this work has successfully applied a variable transformation to simplify the partial differential equation of solute transport problem. And an analytical serial solution for the simplified equation is then established by the so-called separated variable method and the superposition method. Compared with numerical methods such as finite different method and finite element method, this analytical solution is more accurate and of higher computation efficiency. In addition, the solution procedure presented could be extended for applications such as quality analysis, design of physical experimentation, or parameter estimation and measurement of solute transport problems.展开更多
Because of its long processing time, low operating cost, simultaneous processing of multiple pollutants, PRB （permeable reactive barrier） is a commonly used technique for groundwater pollution remediation in western...Because of its long processing time, low operating cost, simultaneous processing of multiple pollutants, PRB （permeable reactive barrier） is a commonly used technique for groundwater pollution remediation in western countries. But relative research about the PRB technology in China is still in its infancy. We reviewed the PRB structure, PRB repair mechanism and application progress at home and abroad. Aiming at the problems of PRB technology at reaction material selection, pollutant repair mechanism, removal of various pollution components and site installation design, development direction of the PRB technology was prospected.展开更多
基金supported by the National Natural Science Foundation of China (40874022)Public Utility Research Project (200808053)973 program (2008CB425703)
文摘The contemporary tectonic stress field in China is obtained on the basis of Chinese stress field database and Harvard CMT catalogue. Result of the inverted tectonic stresses shows that the maximum principal stress axis strikes nearly north-south direction in the west part of Tibet plateau, ENE direction in North China. In Central China, its strikes show a ra- diated pattern, i.e., NNE in north part and NNW in south part. The detailed stress field parameters of nearly whole China are given and can be used in geodynamic stress field simulation and earthquake prediction.
基金Acknowledgements： The work was supported by the National Natural Science Foundation of China （No. 90502006/D0123）, Hunan provincial Natural Science Foundation of China （No. 06JJ3020） and Scientific Research Fund of Hunan Provincial Education Department （No. 06C500）.
文摘The mechanism of transport of chemicals in soil is an important research topic of environmental science and engineering, and some models and methods for a variety of solute transport problems have been done. However. most of previous works are usually for a soil column of infinite dimension. Starting from the one-dimension transient solute transport equation and its boundary and initial condition for a solute transport problem of soil column of finite length, this work has successfully applied a variable transformation to simplify the partial differential equation of solute transport problem. And an analytical serial solution for the simplified equation is then established by the so-called separated variable method and the superposition method. Compared with numerical methods such as finite different method and finite element method, this analytical solution is more accurate and of higher computation efficiency. In addition, the solution procedure presented could be extended for applications such as quality analysis, design of physical experimentation, or parameter estimation and measurement of solute transport problems.
基金Supported by Graduate Science and Technology Innovation Foundation Item of Central University Basic Science Research Service Charge,China(ZY20150305)
文摘Because of its long processing time, low operating cost, simultaneous processing of multiple pollutants, PRB （permeable reactive barrier） is a commonly used technique for groundwater pollution remediation in western countries. But relative research about the PRB technology in China is still in its infancy. We reviewed the PRB structure, PRB repair mechanism and application progress at home and abroad. Aiming at the problems of PRB technology at reaction material selection, pollutant repair mechanism, removal of various pollution components and site installation design, development direction of the PRB technology was prospected.
