The Jaynes-Cummings model （JCM） is studied in the absence of the rotating-wave approximation （RWA） by a coherent-state expansion technique. In comparison with the previous paper in which the coherent-state expansi...The Jaynes-Cummings model （JCM） is studied in the absence of the rotating-wave approximation （RWA） by a coherent-state expansion technique. In comparison with the previous paper in which the coherent-state expansion was performed only to the third order, we carry out in this paper a complete expansion to demonstrate exactly the dynamics of the JCM without the RWA. Our study gives a systematic method to solve the non-RWA problem, which would be useful in various physical systems, e.g., in a system with an ultracold trapped ion experiencing the running waves of lasers.展开更多
The quark potential model is extended to include the sea quark excitation using the random phase approximation. The effective quark interaction preserves the important QCD properties — chiral symmetry and confinement...The quark potential model is extended to include the sea quark excitation using the random phase approximation. The effective quark interaction preserves the important QCD properties — chiral symmetry and confinement simultaneously. A primary qualitative analysis shows that the π meson as a well-known typical Goldstone boson and the other mesons made up of valence quark pair such as the ρ meson can also be described in this extended quark potential model.展开更多
The triatomic and tetratomic gas molecule adsorption effects on the electrical conductivity of graphene areinvestigated by the tight-binding model,Green’s function method,and coherent potential approximation.We find ...The triatomic and tetratomic gas molecule adsorption effects on the electrical conductivity of graphene areinvestigated by the tight-binding model,Green’s function method,and coherent potential approximation.We find thatthe electrical conductivity of graphene sheet is sensitive to the adsorption of these gases.展开更多
The goal of this study is to evaluate the drift of litterfall from forest to adjacent areas, validate a method to estimate the drift with water balance, direction and speed of winds and quantify the nutrients of litte...The goal of this study is to evaluate the drift of litterfall from forest to adjacent areas, validate a method to estimate the drift with water balance, direction and speed of winds and quantify the nutrients of litterfall in nearby area of the forest patch as function of distance. This phenomenon can be considered an ecosystem service to improve soil quality of the agriculture crops around the forests by nutrient input coming from the litterfall. The experiment was installed in adjacent areas of the tropical forest at central region of the State of Minas Gerais, Brazil. The branches, reproductive material and leaves which fell were measured for three years into the forest and adjacents areas. The sampled nets were located on edge and equal distances from the edge. It＇s analyzed and estimated the contribution of the litterfall components to adjacent areas by air. The quantity of litterfall by distance had large variation between adjacent areas. And it was confirmed that model estimated the leaf drift by distance with good precision.展开更多
For the Generalized Linear Model (GLM), under some conditions including that the specification of the expectation is correct, it is shown that the Quasi Maximum Likelihood Estimate (QMLE) of the parameter-vector is as...For the Generalized Linear Model (GLM), under some conditions including that the specification of the expectation is correct, it is shown that the Quasi Maximum Likelihood Estimate (QMLE) of the parameter-vector is asymptotic normal. It is also shown that the asymptotic covariance matrix of the QMLE reaches its minimum (in the positive-definte sense) in case that the specification of the covariance matrix is correct.展开更多
Based on the modification of the simplified coherent potential approximation （SCPA）, a model is developed to calculate the composition dependence of the band gap energy of Ⅲ-V ternary alloys with the same anion. Th...Based on the modification of the simplified coherent potential approximation （SCPA）, a model is developed to calculate the composition dependence of the band gap energy of Ⅲ-V ternary alloys with the same anion. The derived equation is used to fit the experimental band gap energy of InxAl1-xN, InxGa1-xN and A1xGal xN with x from 0 to 1. It is found that the fitting results are better than those done by using SCPA. The fitting results are also better than those obtained by using the formula with a small bowing coefficient, especially for InxAl1-xN. In addition, our model can also be used to describe the composition de- pendence of band gap energy of other Ⅲ-V ternary alloys.展开更多
基金The project supported by National Natural Science Foundation of China under Grant Nos. 10474118 and 10274093, the National Fundamental Research Program of China under Grant No. 2005CB724502, and the Foundation from Educational Department of Sichuan Province of China under Grant No. 2004C017
文摘The Jaynes-Cummings model （JCM） is studied in the absence of the rotating-wave approximation （RWA） by a coherent-state expansion technique. In comparison with the previous paper in which the coherent-state expansion was performed only to the third order, we carry out in this paper a complete expansion to demonstrate exactly the dynamics of the JCM without the RWA. Our study gives a systematic method to solve the non-RWA problem, which would be useful in various physical systems, e.g., in a system with an ultracold trapped ion experiencing the running waves of lasers.
文摘The quark potential model is extended to include the sea quark excitation using the random phase approximation. The effective quark interaction preserves the important QCD properties — chiral symmetry and confinement simultaneously. A primary qualitative analysis shows that the π meson as a well-known typical Goldstone boson and the other mesons made up of valence quark pair such as the ρ meson can also be described in this extended quark potential model.
文摘The triatomic and tetratomic gas molecule adsorption effects on the electrical conductivity of graphene areinvestigated by the tight-binding model,Green’s function method,and coherent potential approximation.We find thatthe electrical conductivity of graphene sheet is sensitive to the adsorption of these gases.
文摘The goal of this study is to evaluate the drift of litterfall from forest to adjacent areas, validate a method to estimate the drift with water balance, direction and speed of winds and quantify the nutrients of litterfall in nearby area of the forest patch as function of distance. This phenomenon can be considered an ecosystem service to improve soil quality of the agriculture crops around the forests by nutrient input coming from the litterfall. The experiment was installed in adjacent areas of the tropical forest at central region of the State of Minas Gerais, Brazil. The branches, reproductive material and leaves which fell were measured for three years into the forest and adjacents areas. The sampled nets were located on edge and equal distances from the edge. It＇s analyzed and estimated the contribution of the litterfall components to adjacent areas by air. The quantity of litterfall by distance had large variation between adjacent areas. And it was confirmed that model estimated the leaf drift by distance with good precision.
基金Project supported by the National Natural Science Foundation of China.
文摘For the Generalized Linear Model (GLM), under some conditions including that the specification of the expectation is correct, it is shown that the Quasi Maximum Likelihood Estimate (QMLE) of the parameter-vector is asymptotic normal. It is also shown that the asymptotic covariance matrix of the QMLE reaches its minimum (in the positive-definte sense) in case that the specification of the covariance matrix is correct.
基金supported by the Special Funds for Major State Basic Research Project (Grant No. 2011CB301900)the National Natural Science Foundation of China (Grant No. 60990311)
文摘Based on the modification of the simplified coherent potential approximation （SCPA）, a model is developed to calculate the composition dependence of the band gap energy of Ⅲ-V ternary alloys with the same anion. The derived equation is used to fit the experimental band gap energy of InxAl1-xN, InxGa1-xN and A1xGal xN with x from 0 to 1. It is found that the fitting results are better than those done by using SCPA. The fitting results are also better than those obtained by using the formula with a small bowing coefficient, especially for InxAl1-xN. In addition, our model can also be used to describe the composition de- pendence of band gap energy of other Ⅲ-V ternary alloys.
