A novel analytical model for the thin film silicon on insulator (TFSOI) reduced surface field (RESURF) devices has been proposed.Based on the 2-D Poisson equation solution,the analytical expressions for the surface po...A novel analytical model for the thin film silicon on insulator (TFSOI) reduced surface field (RESURF) devices has been proposed.Based on the 2-D Poisson equation solution,the analytical expressions for the surface potential and field distributions are derived.From this analysis,the optimum design condition for the maximum breakdown voltage is obtained.The dependence of the maximum breakdown voltage on the drift region length is examined and the relationship between the critical doping concentration and the front- and back- interface oxide layer thickness is discussed.The numerical simulation performed by the advanced semiconductor simulation tool,DESSIS-ISE,has been shown to support the analytical results.展开更多
Ls-DYNA software is adopted to conduct research of numerical simulation on hot stamping of side impact beam to calculate the temperature field distribution, stress field distribution, forming limit diagram （FLD） fig...Ls-DYNA software is adopted to conduct research of numerical simulation on hot stamping of side impact beam to calculate the temperature field distribution, stress field distribution, forming limit diagram （FLD） figure, etc. in the course of hot stamping so as to predict and analyze the formability of parts. ProCAST software is employed to conduct research of numerical simulation on solid quenching course concerning hot stamping to calculate temperature field distri- bution of tools and component of muhiple stamping cycles. The results obtained from numerical simulation can provide significant reference value to hot stamping part design, formability predication and tools cooling system design.展开更多
The theory of magnetic circuit design, the constitutive equations of a magneto-theological fluid, and the load properties of belt conveyors were used to design a magneto-rheological soft starter test-bed. The magnetic...The theory of magnetic circuit design, the constitutive equations of a magneto-theological fluid, and the load properties of belt conveyors were used to design a magneto-rheological soft starter test-bed. The magnetic field distribution in the working gap was analyzed and the current-speed relationship was investigated. A mathematical model for the time response was deduced. The results show that a linear relationship between current and magnetic field is seen when the magnetic materials are not saturated and the magnetic field is uniform in the working section. The rotation speed of the driven shaft changes linearly with increasing time. The response is rapid and can be as short as milliseconds. This meets the starting requirements of belt conveyors.展开更多
An optimal layout or three-dimensional spatial distribution of stopes guarantees the maximum profitability over life span of an underground mining operation.Thus,stope optimization is one of the key areas in undergrou...An optimal layout or three-dimensional spatial distribution of stopes guarantees the maximum profitability over life span of an underground mining operation.Thus,stope optimization is one of the key areas in underground mine planning practice.However,the computational complexity in developing an optimal stope layout has been a reason for limited availability of the algorithms offering solution to this problem.This article shares a new and efficient heuristic algorithm that considers a three-dimensional ore body model as an input,maximizes the economic value,and satisfies the physical mining and geotechnical constraints for generating an optimal stope layout.An implementation at a copper deposit demonstrates the applicability and robustness of the algorithm.A parallel processing based modification improving the performance of the original algorithm in terms of enormous computational time saving is also presented.展开更多
We have investigated the distribution of the electric field in p-i-n GaN avalanche photodiodes under different reverse bias values. type and separate absorption and multiplication （SAM） type We have also analyzed th...We have investigated the distribution of the electric field in p-i-n GaN avalanche photodiodes under different reverse bias values. type and separate absorption and multiplication （SAM） type We have also analyzed the influences of the parameters of each layer, including width and concentration, on the distribution of the electric field, especially on the breakdown voltage. It is found that a relatively high concentration of p-GaN （higher than 1×10^18 cm-3） and low cartier concentration of i-GaN （lower than 5×1016 cm-3） are helpful to restrict the electric field and reduce the breakdown voltage. In a SAM （p-i-n-i-n） structure, a suitable choice should be made for the concentration and thickness of the intermediate n-GaN layer in order to decrease breakdown voltage and prevent the device from degenerating into a p-i-n structure. Finally, the optimized material parameters of each layer are proposed.展开更多
文摘A novel analytical model for the thin film silicon on insulator (TFSOI) reduced surface field (RESURF) devices has been proposed.Based on the 2-D Poisson equation solution,the analytical expressions for the surface potential and field distributions are derived.From this analysis,the optimum design condition for the maximum breakdown voltage is obtained.The dependence of the maximum breakdown voltage on the drift region length is examined and the relationship between the critical doping concentration and the front- and back- interface oxide layer thickness is discussed.The numerical simulation performed by the advanced semiconductor simulation tool,DESSIS-ISE,has been shown to support the analytical results.
基金National Science and Technology Supporting Program of China(No.20 11BAG03B02)
文摘Ls-DYNA software is adopted to conduct research of numerical simulation on hot stamping of side impact beam to calculate the temperature field distribution, stress field distribution, forming limit diagram （FLD） figure, etc. in the course of hot stamping so as to predict and analyze the formability of parts. ProCAST software is employed to conduct research of numerical simulation on solid quenching course concerning hot stamping to calculate temperature field distri- bution of tools and component of muhiple stamping cycles. The results obtained from numerical simulation can provide significant reference value to hot stamping part design, formability predication and tools cooling system design.
基金supported by the National Natural Science Foundation of China (Nos. 50975275 and 51075386)
文摘The theory of magnetic circuit design, the constitutive equations of a magneto-theological fluid, and the load properties of belt conveyors were used to design a magneto-rheological soft starter test-bed. The magnetic field distribution in the working gap was analyzed and the current-speed relationship was investigated. A mathematical model for the time response was deduced. The results show that a linear relationship between current and magnetic field is seen when the magnetic materials are not saturated and the magnetic field is uniform in the working section. The rotation speed of the driven shaft changes linearly with increasing time. The response is rapid and can be as short as milliseconds. This meets the starting requirements of belt conveyors.
文摘An optimal layout or three-dimensional spatial distribution of stopes guarantees the maximum profitability over life span of an underground mining operation.Thus,stope optimization is one of the key areas in underground mine planning practice.However,the computational complexity in developing an optimal stope layout has been a reason for limited availability of the algorithms offering solution to this problem.This article shares a new and efficient heuristic algorithm that considers a three-dimensional ore body model as an input,maximizes the economic value,and satisfies the physical mining and geotechnical constraints for generating an optimal stope layout.An implementation at a copper deposit demonstrates the applicability and robustness of the algorithm.A parallel processing based modification improving the performance of the original algorithm in terms of enormous computational time saving is also presented.
基金supported by the National Science Fund for Distinguished Young Scholars (Grant No. 60925017)the National Natural Science Foundation of China (Grant Nos. 10990100,60836003 and 60776047)
文摘We have investigated the distribution of the electric field in p-i-n GaN avalanche photodiodes under different reverse bias values. type and separate absorption and multiplication （SAM） type We have also analyzed the influences of the parameters of each layer, including width and concentration, on the distribution of the electric field, especially on the breakdown voltage. It is found that a relatively high concentration of p-GaN （higher than 1×10^18 cm-3） and low cartier concentration of i-GaN （lower than 5×1016 cm-3） are helpful to restrict the electric field and reduce the breakdown voltage. In a SAM （p-i-n-i-n） structure, a suitable choice should be made for the concentration and thickness of the intermediate n-GaN layer in order to decrease breakdown voltage and prevent the device from degenerating into a p-i-n structure. Finally, the optimized material parameters of each layer are proposed.
