一种全新的物理计算工具——计算地图

物理计算难就难在物理量多且关系错综复杂,而一张类似生活中交通地图的辅助工具"计算地图",能够把各个物理量的关系一览无余地呈现在计算者面前,从而很好地为物理计算导航.文章分别介绍了什么是计算地图、计算地图的作用及其导航原理分析,以及绘制计算地图时要遵循的原则.     

锂电池中的计算物理学

从计算物理学角度深入解析与锂电池特性关联的物理基础,对优化锂电池的设计并推动其发展具有重要的指导意义。文章系统总结了锂电池中物理现象与物理原理的对应关系,通过分析物理模型及其作用机制,勾勒出锂电池模型的物理图像,提炼出相关描述因子及其计算物理方法。针对锂电池中科学问题的计算、模拟与仿真多尺度技术的发展,以及近年来基于机器学习与高通量计算方法的研究进展,可以预见多尺度模拟与高智能计算技术的结合将极大地推进锂电池的快速发展。在锂电池的仿真研究中,确立计算方法尺度、科学基础理论、储能机制与系统的物理形态、仿真与实践的物理关系及科学基础与工程应用构造的五维一体化锂电池分析体系,无论对揭示锂电池中基本物理原理、电池本质属性、计算物理学之间的科学关系,还是对发展基于物理基本原理模型的电池体系构效关系和调控方法,都具有里程碑式的意义。     

Ti,Nb, Al及其二元合金状态方程的第一原理计算及其应用

金属状态方程对于探究金属及合金原子的相互作用中起到了至关重要的作用.本文使用第一原理计算了Ti, Nb, Al及其二元合金能量与原子间距关系(E-r关系),并使用得到的E-r关系计算了金属及合金的体弹性模量,结果与实验值吻合的很好.计算结果表明,使用不同的赝势,计算不同金属表现出不同的适用性;二元合金的E-r曲线处于对应合金化元素曲线之间;并且合金的E-r曲线会更靠近合金内含量较高的元素的E-r曲线;并发现合金E-r关系可通过组成合金的纯金属的E-r关系计算获得,且用该方法计算材料的体弹性模量与实验值非常符合.     

自适应线性神经元方法同轴相对论返波管高频特性的数值分析

 提出一种数值分析周期慢波结构色散特性的模拟法：先采用时域有限差分法和离散傅里叶变换技术计算含周期慢波结构的谐振腔的谐振频率及谐振场分布，再基于周期慢波电路色散关系的周期性质，利用几个特殊色散点由数值组合技术获得周期慢波线的完整色散关系。数值计算了同轴波纹波导中TMon模式的色散关系。亦能用于分析计算任意复杂几何结构的周期慢波线的色散关系。     

自适应线性神经元方法同轴相对论返波管高频特性的数值分析

提出一种数值分析周期慢波结构色散特性的模拟法：先采用时域有限差分法和离散傅里叶变换技术计算含周期慢波结构的谐振腔的谐振频率及谐振场分布,再基于周期慢波电路色散关系的周期性质,利用几个特殊色散点由数值组合技术获得周期慢波线的完整色散关系。数值计算了同轴波纹波导中TMon模式的色散关系。亦能用于分析计算任意复杂几何结构的周期慢波线的色散关系。     

同轴相对论返波管高频特性的数值分析

提出一种数值分析周期慢波结构色散特性的模拟法，先采用时域有限差分法和离散傅里叶变换技术计算含周期慢波结构的谐振腔的谐振频率及谐振场分布，再基于周期慢波电路色散关系的周期性质，利用几个特殊色散点由数值组合技术获得周期慢波线的完整色散关系。数值计算了同轴波纹波导中ＴＭ０ｎ模式的色散关系，亦能用于分析计算任意复杂几何结构的周期慢波线的色散关系。     

光纤布拉格光栅中的隙孤子存在条件

提出光纤布拉格光栅中产生隙孤子的条件和参量制约关系。利用非线性耦合模式方程建立光纤布拉格光栅中孤子的传播方程,通过扰动方法建立了参量的微分方程,计算得到参量近似解。以周期非线性光学介质中隙孤子存在的条件为依据,数学计算分析得到两组参量关系不等式。最终通过数值计算说明了这些参量之间存在制约关系和物理意义。从而理论上说明了在光纤布拉格光栅中隙孤子存在需要选择适当参量。为光纤布拉格光栅中产生隙孤子的实验和进一步的工程应用提供了理论基础。     

硅p-n结太阳电池对DF激光的响应

 对硅p-n结太阳电池在DF激光辐照下的响应进行了理论和实验研究。推导了p-n结反向饱和电流随温度的近似变化关系。根据该近似关系，计算了太阳电池在DF激光辐照过程中输出电压的变化曲线。计算结果和实验结果之间取得了比较好的一致性。     

光抽运信号的理论分析

在原子辐射跃迁原理的基础上,依据光磁共振实验的基本实验现象建立简化模型,给出光抽运过程中跃迁速率方程,理论计算了光抽运信号光强随外场变化关系以及粒子跃迁弛豫时间随外场的变化关系,理论计算结果与实验符合.     

硅p-n结太阳电池对DF激光的响应

对硅p-n结太阳电池在DF激光辐照下的响应进行了理论和实验研究。推导了p-n结反向饱和电流随温度的近似变化关系。根据该近似关系,计算了太阳电池在DF激光辐照过程中输出电压的变化曲线。计算结果和实验结果之间取得了比较好的一致性。     

Unification theory of classical statistical uncertainty relation and quantum uncertainty relation and its applications

General classical statistical uncertainty relation is deduced and generalized to quantum uncertainty relation. We give a general unification theory of the classical statistical and quantum uncertainty relations, and prove that the classical limit of quantum mechanics is just classical statistical mechanics. It is shown that the classical limit of the general quantum uncertainty relation is the general classical uncertainty relation. Also, some specific applications show that the obtained theory is self-consistent and coincides with those from physical experiments.     

关于玻尔对应原理的思考

文章回顾了对应原理在理解量子力学与经典力学之间关系时的重要作用,举例说明了作用量的数量级可作为量子体系与经典体系的分界.     

Star products and geometric algebra

The formalism of geometric algebra can be described as deformed super analysis. The deformation is done with a fermionic star product, that arises from deformation quantization of pseudoclassical mechanics. If one then extends the deformation to the bosonic coefficients of superanalysis one obtains quantum mechanics for systems with spin. This approach clarifies on the one hand the relation between Grassmann and Clifford structures in geometric algebra and on the other hand the relation between classical mechanics and quantum mechanics. Moreover it gives a formalism that allows to handle classical and quantum mechanics in a consistent manner.     

Noncommutative Classical Mechanics

In this work, I investigate the noncommutative Poisson algebra of classical observables corresponding to a proposed general noncommutative quantum mechanics, Djemai, A. E. F. and Smail, H. (2003). I treat some classical systems with various potentials and some physical interpretations are given concerning the presence of noncommutativity at large scales (celestial mechanics) directly tied to the one present at small scales (quantum mechanics) and its possible relation with UV/IR mixing.     

Wave function of classical particle in linear potential

We study the problem of classical particle in linear potential using the formalism of Hilbert space and tomographic-probability distribution. We solve the Liouville equation for this problem by finding the density matrix satisfying a von Newmann-like equation in the form of a product of the wave functions. We discuss the relation of the classical solution obtained to quantum mechanics.     

Why quantum mechanics?

It is suggested that anoversight occurred in classical mechanics when time-derivatives of observables were treated on the same footing as the undifferentiated observables. Removal of this oversight points in the direction of quantum mechanics. Additional light is thrown on uncertainty relations and on quantum mechanics, as a possible form of a subtle statistical mechanics, by the formulation of aclassical uncertainty relation for a very simple model. The existence of universal motion,i.e., of zero-point energy, is lastly made plausible in terms of a gravitational constant which is time-dependent. By these three considerations an attempt is made to link classical and quantum mechanics together more firmly, thus giving a better understanding of the latter.Paper dedicated to David Bohm on the occasion of his 70th birthday.     

Time as a Geometric Concept Involving Angular Relations in Classical Mechanics and Quantum Mechanics

The goal of this paper is to introduce the notion of a four-dimensional time in classical mechanics and in quantum mechanics as a natural concept related with the angular momentum. The four-dimensional time is a consequence of the geometrical relation in the particle in a given plane defined by the angular momentum. A quaternion is the mathematical entity that gives the correct direction to the four-dimensional time.     

Classical and quantum mechanics of non-abelian gauge fields

Classical and quantum mechanics of non-abelian gauge fields are investigated both with and without spontaneous symmetry breaking. The fundamental subsystem (FS) of Yang-Mills classical mechanics (YMCM) is considered. It is shown to be a Kolmogorov K-system, and hence to have strong statistical properties. Integrable systems are also found, to which in terms of KAM theory Yang-Mills-Higgs classical mechanics (YMHCM) is close. Quantum-mechanical properties of the YM system and their relation to the problem of confinement are discussed.     

Wave Mechanics or Wave Statistical Mechanics

By comparison between equations of motion of geometrical optics and that of classical statistical mechanics, this paper finds that there should be an analogy between geometrical optics and classical statistical mechanics instead of geometrical mechanics and classical mechanics. Furthermore, by comparison between the classical limit of quantum mechanics and classical statistical mechanics, it finds that classical limit of quantum mechanics is classical statistical mechanics not classical mechanics, hence it demonstrates that quantum mechanics is a natural generalization of classical statistical mechanics instead of classical mechanics. Thence quantum mechanics in its true appearance is a wave statistical mechanics instead of a wave mechanics.     

Transient chaos in quantum and classical mechanics

Bogolubov's classical example of statistical relaxation in a many-dimensional linear oscillator is discussed. The relation of the discovered relaxation mechanism to quantum dynamics as well as to some new problems in classical mechanics is considered.