光学概念的延拓和归一

本文指出:由于光学概念和规律(乃至其他物理概念)的普适性,按外延的方法延拓出去,往往能达到充满内在连系是归一效果,使得原概念和规律变得更为深刻、简明、和谐与统一。例如牛顿的一维碰撞定律经过延拓变得能包容回碰、粘碰、穿碰等宏观和微观碰撞的更广泛规律。光学中几个基本量子概念也可以相互延拓而概括归一为和波一粒二象性完全容洽的归一形式,从而更容易得出不确定原理。     

辊道存放型机械式停车设备结构形式

辊道存放型机械式停车设备的仓储式钢架可并排多车位存放轿车和微型客车等无需存车托板。文中介绍其结构形式、工作原理、存取方法以及产品实例。     

当量时间设计方法综述

建筑构件耐火设计当量时间(T-equivalent)法是一种兼有科学性和实用性的性能化消防设计方法.基于不同的等代原则,系统详细地介绍了国内外当量时间的研究进展.     

毫米波雷达导引头技术研究

毫米波雷达导引头是毫米波精确制导技术的重要组成部分.首先介绍了对导引头的基本要求,然后详细介绍了毫米波雷达导引头的工作原理、关键技术、工作模式、主要特点以及典型应用,最后分析了毫米波导引头的发展方向.     

A note on a correspondence principle in nonlinear viscoelastic materials

We show that models for the nonlinear viscoelastic response of solids generated on the basis of a correspondence principle developed by Schapery(1984) do not satisfy the balance of angular momentum for large deformations. This principle, which is valid if the displacement gradients are sufficiently small, has been used in several papers to develop models to describe the fracture of viscoelastic solids, and these studies need to be reexamined in the light of this note.     

大型机组点火系统供电技术的探讨

火力发电厂锅炉点火系统采用等离子点火及稳燃技术,引起供电负荷及厂用电系统变化,为使等离子装置供电电源的安全可靠,对其负荷分析并提出原则性供电方式意见供大家探讨。     

一类常见广义电报方程的概周期解

本文用最大值原理和Banach压缩映像原理研究了一类常见广义电报方程的概周期解问题，证明了该概周期解的存在性及在｜｜u｜｜L-＜1中的唯一性．     

一类单一物品库存系统的最优控制

研究单一物品库存系统的最优控制问题 ,并借助于动态规划原理给出了最优控制律的表达式 ,以使在一个时间周期 [0 ,T]内系统的费用总和的期望值最小     

A nonparametric model of random uncertainties for reduced matrix models in structural dynamics

Random uncertainties in finite element models in linear structural dynamics are usually modeled by using parametric models. This means that: (1) the uncertain local parameters occurring in the global mass, damping and stiffness matrices of the finite element model have to be identified; (2) appropriate probabilistic models of these uncertain parameters have to be constructed; and (3) functions mapping the domains of uncertain parameters into the global mass, damping and stiffness matrices have to be constructed. In the low-frequency range, a reduced matrix model can then be constructed using the generalized coordinates associated with the structural modes corresponding to the lowest eigenfrequencies. In this paper we propose an approach for constructing a random uncertainties model of the generalized mass, damping and stiffness matrices. This nonparametric model does not require identifying the uncertain local parameters and consequently, obviates construction of functions that map the domains of uncertain local parameters into the generalized mass, damping and stiffness matrices. This nonparametric model of random uncertainties is based on direct construction of a probabilistic model of the generalized mass, damping and stiffness matrices, which uses only the available information constituted of the mean value of the generalized mass, damping and stiffness matrices. This paper describes the explicit construction of the theory of such a nonparametric model.     

Ab initio molecular dynamics simulation for structural transition of Zr during rapid quenching processes

We report the results of ab initio molecular dynamics simulation for the structural transition of Zr during two distinct quenching processes (Q1: 4.3 × 10¹³ K/s, Q2: 2.0 × 10¹⁴ K/s). In both the quenching processes, structural transition details have been analyzed by pair correlation functions g(r) and bond pair analysis technique. It is shown that the liquid Zr transforms to a metastable bcc phase (β-Zr) at the temperature about 1000 K as quenched at the rate of 4.3 × 10¹³ K/s. When quenched at 2.0 × 10¹⁴ K/s, however, the crystallization is suppressed and the liquid Zr is frozen into a glass state. The bond pair analysis reveals that the dominant bond pairs in the liquid and glass states are the 1551, 1541, 1431, 1661 and 1441, indicating that the short range order in both states mostly consists of icosahedral, tetrahedral and bcc clusters.