An analytical model of the surface field distribution and breakdown voltage of the reduced surface field lateral double diffusion MOS transistor is proposed.Based on the 2-D Poisson's equation solution,the derived...An analytical model of the surface field distribution and breakdown voltage of the reduced surface field lateral double diffusion MOS transistor is proposed.Based on the 2-D Poisson's equation solution,the derived model gives the closed form solutions of the surface potential and electrical field distributions as a function of the structure parameters and drain bias.A criterion for obtaining the optimal trade-off between the breakdown voltage and on-resistance is also presented to serve to quantify the maximum breakdown voltage and optimal relations of all design parameters.Analytical results are shown in good agreement with the numerical analysis obtained by the semiconductor device simulator MEDICI and previous reported experimental data.展开更多
A new technique for the analysis of the three-dimensional collapse failure mechanism and the ground surface settlements for the large-diameter shield tunnels were presented.The technique is based on a velocity field m...A new technique for the analysis of the three-dimensional collapse failure mechanism and the ground surface settlements for the large-diameter shield tunnels were presented.The technique is based on a velocity field model using more different truncated solid conical blocks to clarify the multiblock failure mechanism.Furthermore,the shape of blocks between the failure surface and the tunnel face was considered as an entire circle,and the supporting pressure was assumed as non-uniform distribution on the tunnel face and increased with the tunnel embedded depth.The ground surface settlements and failure mechanism above large-diameter shield tunnels were also investigated under different supporting pressures by the finite difference method.展开更多
A novel scale-flee network model based on clique （complete subgraph of random size） growth and preferential attachment was proposed. The simulations of this model were carried out. And the necessity of two evolving ...A novel scale-flee network model based on clique （complete subgraph of random size） growth and preferential attachment was proposed. The simulations of this model were carried out. And the necessity of two evolving mechanisms of the model was verified. According to the mean-field theory, the degree distribution of this model was analyzed and computed. The degree distribution function of vertices of the generating network P（d） is 2m^2m1^-3（d-m1 ＋ 1）^-3, where m and m1 denote the number of the new adding edges and the vertex number of the cliques respectively, d is the degree of the vertex, while one of cliques P（k） is 2m^2Ek^-3, where k is the degree of the clique. The simulated and analytical results show that both the degree distributions of vertices and cliques follow the scale-flee power-law distribution. The scale-free property of this model disappears in the absence of any one of the evolving mechanisms. Moreover, the randomicity of this model increases with the increment of the vertex number of the cliques.展开更多
Residual stress distributions in 7075 aluminum alloy thick plates with different thicknesses and different quenching speeds were measured. A shape function of stress distribution was proposed based on the internal str...Residual stress distributions in 7075 aluminum alloy thick plates with different thicknesses and different quenching speeds were measured. A shape function of stress distribution was proposed based on the internal stress distribution characteristics of aluminum alloy. Using nonlinear regression technology,the function between stress value of key points on internal stress curve and surface stress of the plate was obtained. Based on the measured surface stress,stress value of key points and stress distribution shape,the internal stress distribution can be reconstructed. The experiments show that the model is of good engineering practicality.展开更多
A plane-symmetric inhomogeneous cosmological model of perfect fluid distribution with electro-magnetic field is obtained. F12 is the non-vanishing component of electromagnetic field tensor. To get a deterministic solu...A plane-symmetric inhomogeneous cosmological model of perfect fluid distribution with electro-magnetic field is obtained. F12 is the non-vanishing component of electromagnetic field tensor. To get a deterministic solution, we assume the free gravitational field is Petrov type-Ⅱ non-degenerate. Some physical and geometric properties of the model are also discussed.展开更多
In order to study the distribution of lateral floor abutment pressure at a working face,we first used elasticity theory to establish a distribution model of lateral floor abutment pressure and then analysed its distri...In order to study the distribution of lateral floor abutment pressure at a working face,we first used elasticity theory to establish a distribution model of lateral floor abutment pressure and then analysed its distribution.Second,we established a three-dimensional numerical simulation model of the Haizi Coal Mine No.86 mining area by using FLAC^（3D）（ITASCA Consulting Group） software.We investigated the distribution of lateral floor abutment pressure of a stope,which indicated that the position of abutment pressure peak varies at different floor depths.We then determined the rational reinforcement range of a floor roadway,based on the conclusion reached earlier.Finally,we used our conclusions in support of the No.86 mining area crossing-roadway.The supported crossing-roadway remained stable when mining the upper workface,which validates the accuracy of our numerical simulation and provides a future reference for the support of span-roadways under similar conditions.展开更多
Motivated by the reset option with n predetermined dates analyzed by W.Cheng, we consider a kind of reset option with uncertain dates by introducing N pie-specifiedbarrier levels. We claim this reset option consists o...Motivated by the reset option with n predetermined dates analyzed by W.Cheng, we consider a kind of reset option with uncertain dates by introducing N pie-specifiedbarrier levels. We claim this reset option consists of some standard knock-in and knock-out barrieroptions. The closed-form pricing formula is derived by means of a PDE's approach.展开更多
文摘An analytical model of the surface field distribution and breakdown voltage of the reduced surface field lateral double diffusion MOS transistor is proposed.Based on the 2-D Poisson's equation solution,the derived model gives the closed form solutions of the surface potential and electrical field distributions as a function of the structure parameters and drain bias.A criterion for obtaining the optimal trade-off between the breakdown voltage and on-resistance is also presented to serve to quantify the maximum breakdown voltage and optimal relations of all design parameters.Analytical results are shown in good agreement with the numerical analysis obtained by the semiconductor device simulator MEDICI and previous reported experimental data.
基金Project(41202220) supported by the National Natural Science Foundation of ChinaProject(2011YYL034) supported by the Fundamental Research Funds for the Central Universities,China
文摘A new technique for the analysis of the three-dimensional collapse failure mechanism and the ground surface settlements for the large-diameter shield tunnels were presented.The technique is based on a velocity field model using more different truncated solid conical blocks to clarify the multiblock failure mechanism.Furthermore,the shape of blocks between the failure surface and the tunnel face was considered as an entire circle,and the supporting pressure was assumed as non-uniform distribution on the tunnel face and increased with the tunnel embedded depth.The ground surface settlements and failure mechanism above large-diameter shield tunnels were also investigated under different supporting pressures by the finite difference method.
基金Projects(60504027,60573123) supported by the National Natural Science Foundation of ChinaProject(20060401037) supported by the National Postdoctor Science Foundation of ChinaProject(X106866) supported by the Natural Science Foundation of Zhejiang Province,China
文摘A novel scale-flee network model based on clique （complete subgraph of random size） growth and preferential attachment was proposed. The simulations of this model were carried out. And the necessity of two evolving mechanisms of the model was verified. According to the mean-field theory, the degree distribution of this model was analyzed and computed. The degree distribution function of vertices of the generating network P（d） is 2m^2m1^-3（d-m1 ＋ 1）^-3, where m and m1 denote the number of the new adding edges and the vertex number of the cliques respectively, d is the degree of the vertex, while one of cliques P（k） is 2m^2Ek^-3, where k is the degree of the clique. The simulated and analytical results show that both the degree distributions of vertices and cliques follow the scale-flee power-law distribution. The scale-free property of this model disappears in the absence of any one of the evolving mechanisms. Moreover, the randomicity of this model increases with the increment of the vertex number of the cliques.
基金Projects(2005CB623708, 2010CB731703) supported by the National Basic Research Program of China
文摘Residual stress distributions in 7075 aluminum alloy thick plates with different thicknesses and different quenching speeds were measured. A shape function of stress distribution was proposed based on the internal stress distribution characteristics of aluminum alloy. Using nonlinear regression technology,the function between stress value of key points on internal stress curve and surface stress of the plate was obtained. Based on the measured surface stress,stress value of key points and stress distribution shape,the internal stress distribution can be reconstructed. The experiments show that the model is of good engineering practicality.
文摘A plane-symmetric inhomogeneous cosmological model of perfect fluid distribution with electro-magnetic field is obtained. F12 is the non-vanishing component of electromagnetic field tensor. To get a deterministic solution, we assume the free gravitational field is Petrov type-Ⅱ non-degenerate. Some physical and geometric properties of the model are also discussed.
基金supported by the National Basic Research Program of China(No.2010CB226805)the National Natural Science Foundation of China(Nos.50874103 and 50974115)+1 种基金the Natural Science Foundation of Jiangsu Province(No.KB2008135)the State Key Laboratory Fund(No.SKLGDUEK0905)
文摘In order to study the distribution of lateral floor abutment pressure at a working face,we first used elasticity theory to establish a distribution model of lateral floor abutment pressure and then analysed its distribution.Second,we established a three-dimensional numerical simulation model of the Haizi Coal Mine No.86 mining area by using FLAC^（3D）（ITASCA Consulting Group） software.We investigated the distribution of lateral floor abutment pressure of a stope,which indicated that the position of abutment pressure peak varies at different floor depths.We then determined the rational reinforcement range of a floor roadway,based on the conclusion reached earlier.Finally,we used our conclusions in support of the No.86 mining area crossing-roadway.The supported crossing-roadway remained stable when mining the upper workface,which validates the accuracy of our numerical simulation and provides a future reference for the support of span-roadways under similar conditions.
基金This research is supported by the National Natural Science Foundation of China(No.10171078)
文摘Motivated by the reset option with n predetermined dates analyzed by W.Cheng, we consider a kind of reset option with uncertain dates by introducing N pie-specifiedbarrier levels. We claim this reset option consists of some standard knock-in and knock-out barrieroptions. The closed-form pricing formula is derived by means of a PDE's approach.
