A Continuous Transition Between Quantum and Classical Mechanics. II

Examples are worked out using a new equation proposed in the previous paper to show that it has new physical predictions for mesoscopic systems.     

Squeezing and Quantum Canonical Transformations

In this paper we present an approach to quantum mechanical canonical transformations. Our main result is that time-dependent quantum canonical transformations can always be cast in the form of squeezing operators. We revise the main properties of these operators in regard to its Lie group properties, how two of them can be combined to yield another operator of the same class and how can also be decomposed and fragmented. In the second part of the paper we show how this procedure works extremely well for the time-dependent quantum harmonic oscillator. The issue of the systematic construction of quantum canonical transformations is also discussed along the lines of Dirac, Wigner, and Schwinger ideas and to the more recent work by Lee. The main conclusion is that the classical phase space transformation can be maintained in the operator formalism but the construction of the quantum canonical transformation is not clearly related to the classical generating function of a classical canonical transformation. We hereby propose the much more efficient method given by the squeezing operators. This method has also been proved to be very useful, by one of the authors, in the framework of the dynamical symmetries (Cerveró, J. M. (1999). International Journal of Theoretical Physics 38, 2095–2109).     

波动力学的引路人——L.德布罗意

从社会和个人的角度探索了德布罗意成为波动力学之引路人的原因，并在此基础上进一步对德布罗意独具特色的治学方法作了尝试性的总结，章最后给出了几点现实性的总结，章最后给出了几点现实性的思考与启示。     

Interfacial tension of the chiral Potts model

We calculate the interfacial tension of theN-state chiral Potts model by solving the functional relations for the transfer matrices of the model with skewed boundary conditions. Our result is valid for the general physical model (with positive Boltzmann weights) and at all subcritical temperatures. The interfacial tension has been calculated previously for the superintegrable chiral Potts model with skewed boundary conditions. UsingZ-invariance, Baxter has argued that the interfacial tension of this model should be the same as the interfacial tension of the general physical model. We show that this is indeed the case.     

Positivity of entropy production in nonequilibrium statistical mechanics

We analyze different mechanisms of entropy production in statistical mechanics, and propose formulas for the entropy production ratee() in a state . When is steady state describing the long term behavior of a system we show thate()0, and sometimes we can provee()>0.     

饱和水蒸汽与水的焓与熵参数的新关联式

饱和水蒸汽与水的焓与熵参数的新关联式李斯特，马润梅，吴冷（北京化工大学机械工程系北京１０００２９）关键词统计力学，剩余函数，焓与熵１引言本文根据统计力学与热力学剩余函数原理，结合本课题组曾已建立的饱和水蒸汽与水的新简明状态方程模型，经推导出一则适合于...     

Adatom concentration on GaAs(001) during MBE annealing

We study the concentration of adatoms on GaAs(001) during annealing under MBE conditions. By rapidly cooling the sample from typical growth temperatures and typical As overpressures, the thermal concentration of adatoms can be frozen into small islands on the terraces. The area of the resulting islands is measured with STM far from terrace steps, giving an estimate of the concentration of adatoms during equilibrium. We find that a surprisingly large concentration of adatoms is present for typical growth temperatures, e.g. 0.18 monolayer at 600°C. Possible consequences for current growth models are discussed.     

裸爆和特制半球形结构内爆超压对比实验研究

 爆炸焊接过程会产生爆炸地震、冲击波、有毒气体和噪音等有害效应。设计并制作一个直径为36 m、入口和排烟口直径分别为8 m的半球形结构,用以降低爆炸焊接过程中产生的超压影响。为了研究实际超压降低效果,进行了裸爆和按1/6比例建立的半球形结构内爆炸的超压对比实验。实验结果表明：当超压的传播距离大于20 m时,这种半球形结构能有效降低爆炸焊接过程中产生的超压;对于相同的超压传播距离,切线方向（垂直于半球形结构入口方向）比径向方向（半球形结构入口方向）的超压降低效果好。结合冲击波的传播和反射特点,对超压降低的可能原因进行了分析。     

Verification of the spin-weighted spheroidal equation in the case of s=1

The spin-weighted spheroidal equation in the case of s = 1 is studied. By transforming the independent variables, we make it take the Schrdinger-like form. This Schrdinger-like equation is very interesting in itself. We investigate it by using super-symmetric quantum mechanics and obtain the ground eigenvalue and eigenfunction, which are consistent with the results previously obtained.     

非完整约束奇异广义力学系统的Poincaré-Cartan积分

对受高阶微商非完整约束并用奇异Lagrange量描述的广义力学系 统，基于广义Apell-Четаев约束条件，并考虑到系统的内在约束，导出了该非完整 约 束奇异广义力学系统的广义Poincaré-Cartan积分不变量. 并证明了该不变量与非完整约束 奇异广义力学系统的广义正则方程等价.