运用量子理论推导和数值计算相结合的方法,本文首先得到了一维势箱函数的示意图及其模型.接着,全面、系统地研究了量子理论中N维势箱函数的波函数、能级和概率密度.最后,运用MATLAB软件对势箱函数的所有特性进行了仿真模拟.我们发现:N...运用量子理论推导和数值计算相结合的方法,本文首先得到了一维势箱函数的示意图及其模型.接着,全面、系统地研究了量子理论中N维势箱函数的波函数、能级和概率密度.最后,运用MATLAB软件对势箱函数的所有特性进行了仿真模拟.我们发现:N维势箱中粒子的能量是量子化的、不连续;量子数n不能为零,且n越大对应的能级越高,而质量m越大,对应的能级越低.一般条件下,一维势箱长度a越大(粒子运动范围越大),对应的能级越低;节点数为n-1,节点越多,波长越短,频率越高,能级越高.二维势箱函数波函数的峰值个数为n x 0x0E䥺SymboltB@0x0Fn y,且与Ψ=0平面的交线数也为n x 0x0E䥺SymboltB@0x0Fn y;概率密度分布的极大值个数也为n x 0x0E䥺SymboltB@0x0Fn y.对于简并度,一般情况下,二维势箱模型下的粒子的简并度是不确定的;但对于二维正方势箱函数模型,其箱内微观粒子的能级简并度分为特殊和一般两种情况.三维势箱函数的简并度为n x+n y+n z.最后,首次借助MATLAB软件的色彩实现了四维表现,得到了三维势箱函数的四维空间切片图.这种可视化的结果与理论结果完全一致,这对于抽象性概念的理解具有重要意义.展开更多
According to the stationary principle of potential energy and the generalized coordinate method, a stiffness matrix of a beam element considering distortion effects is derived. Using the stiffness matrix of the beam e...According to the stationary principle of potential energy and the generalized coordinate method, a stiffness matrix of a beam element considering distortion effects is derived. Using the stiffness matrix of the beam element, a finite element program for computing thin-walled box steel beams is developed. And the program can take the section distortion and warping effects into account. The influences of diaphragm spacing on the mechanical behavior of thin-walled box beams are analyzed by the program. The numerical analysis shows that setting diaphragms have the greatest influence on the distortion normal stress, while there is very little influence on the bending normal stress. Only when the distance of adjacent diaphragms decreases to a certain value, will the distortion normal stress in the thin-walled box beam obviously reduce under the distortion load. Finally, a distortion-warping coefficient γ is introduced for simplifying the calculation of the longitudinal normal stress of thin-walled box beams. When the ratio of diaphragms adjacent space L to the maximum section dimension H is less than 2, the distortion-warping coefficient γ tends to one, which means that the distortion normal stress of the thin-walled box beam tends to zero, and the effect of the section distortion can be ignored.展开更多
This paper analyzes the status and the development trend of refrigerator fresh-keeping technologies domestically and internationally, introduces several popular fresh-keeping technologies, elaborates on the principles...This paper analyzes the status and the development trend of refrigerator fresh-keeping technologies domestically and internationally, introduces several popular fresh-keeping technologies, elaborates on the principles and characteristics of several fresh-keeping technologies, and put forth that the future research should be focused on the different needs of customers.展开更多
In recent years, the world economic situation and container shipping industry has been fluctuated drastically, which has complicated the liner shipping companies＇ operation. The conventional issue of overcapacity due...In recent years, the world economic situation and container shipping industry has been fluctuated drastically, which has complicated the liner shipping companies＇ operation. The conventional issue of overcapacity due to the ＂equipment battle＂, and the destructive competition have further stimulated the operating intricacy within the container sector. That would be interesting to explore the chartering strategies of CMA CGM （Compagnie Maritime d＇Affretement Compagnie Generale Maritime） in such a volatile market as any capacity adjustment dictates a line＇s profit line. Nevertheless, the usefulness of ship chartering is not only confined to the operational level but also the strategic level. Throughout the analysis of CMA CGM＇s fleet trend, fleet deployment as well as chartering activities, it can illustrate the above concepts and observe a little bit further about the strategic movement of CMA CGM.展开更多
文摘运用量子理论推导和数值计算相结合的方法,本文首先得到了一维势箱函数的示意图及其模型.接着,全面、系统地研究了量子理论中N维势箱函数的波函数、能级和概率密度.最后,运用MATLAB软件对势箱函数的所有特性进行了仿真模拟.我们发现:N维势箱中粒子的能量是量子化的、不连续;量子数n不能为零,且n越大对应的能级越高,而质量m越大,对应的能级越低.一般条件下,一维势箱长度a越大(粒子运动范围越大),对应的能级越低;节点数为n-1,节点越多,波长越短,频率越高,能级越高.二维势箱函数波函数的峰值个数为n x 0x0E䥺SymboltB@0x0Fn y,且与Ψ=0平面的交线数也为n x 0x0E䥺SymboltB@0x0Fn y;概率密度分布的极大值个数也为n x 0x0E䥺SymboltB@0x0Fn y.对于简并度,一般情况下,二维势箱模型下的粒子的简并度是不确定的;但对于二维正方势箱函数模型,其箱内微观粒子的能级简并度分为特殊和一般两种情况.三维势箱函数的简并度为n x+n y+n z.最后,首次借助MATLAB软件的色彩实现了四维表现,得到了三维势箱函数的四维空间切片图.这种可视化的结果与理论结果完全一致,这对于抽象性概念的理解具有重要意义.
基金Specialized Research Fund for the Doctoral Program of Higher Education (No.20070247002)
文摘According to the stationary principle of potential energy and the generalized coordinate method, a stiffness matrix of a beam element considering distortion effects is derived. Using the stiffness matrix of the beam element, a finite element program for computing thin-walled box steel beams is developed. And the program can take the section distortion and warping effects into account. The influences of diaphragm spacing on the mechanical behavior of thin-walled box beams are analyzed by the program. The numerical analysis shows that setting diaphragms have the greatest influence on the distortion normal stress, while there is very little influence on the bending normal stress. Only when the distance of adjacent diaphragms decreases to a certain value, will the distortion normal stress in the thin-walled box beam obviously reduce under the distortion load. Finally, a distortion-warping coefficient γ is introduced for simplifying the calculation of the longitudinal normal stress of thin-walled box beams. When the ratio of diaphragms adjacent space L to the maximum section dimension H is less than 2, the distortion-warping coefficient γ tends to one, which means that the distortion normal stress of the thin-walled box beam tends to zero, and the effect of the section distortion can be ignored.
文摘This paper analyzes the status and the development trend of refrigerator fresh-keeping technologies domestically and internationally, introduces several popular fresh-keeping technologies, elaborates on the principles and characteristics of several fresh-keeping technologies, and put forth that the future research should be focused on the different needs of customers.
文摘In recent years, the world economic situation and container shipping industry has been fluctuated drastically, which has complicated the liner shipping companies＇ operation. The conventional issue of overcapacity due to the ＂equipment battle＂, and the destructive competition have further stimulated the operating intricacy within the container sector. That would be interesting to explore the chartering strategies of CMA CGM （Compagnie Maritime d＇Affretement Compagnie Generale Maritime） in such a volatile market as any capacity adjustment dictates a line＇s profit line. Nevertheless, the usefulness of ship chartering is not only confined to the operational level but also the strategic level. Throughout the analysis of CMA CGM＇s fleet trend, fleet deployment as well as chartering activities, it can illustrate the above concepts and observe a little bit further about the strategic movement of CMA CGM.
