Analysis of Experiments on Determining the Turbulent Mixing Constant on the Basis of Two-Dimensional Calculations

Based on numerical calculations, the experiments on mixing at the interface of gases are analyzed. Single-mode and random disturbances of the interface and superposition of random disturbances onto long-wave perturbations are considered. Possible reasons for the higher value of the mixing constant obtained in the experiments are discussed.     

30MnNbXt钢组合匹配接头性能的研究

本文为新钢种30MnNbXt设计了一种独特的组合匹配接头,研究了底层奥氏体焊条的合金系统及填充层结构钢焊条的强度对抗裂性的影响,探讨了底层高组配、填充层低组配的组合匹配焊缝特征区的组织特点及接头的力学性能。在西德WS1.7—2.0/3.5型综采支架立柱中应用表明,组合匹配接头可使30MnNbXt钢在室温下焊接时不产生裂纹;接头在焊后状态的使用性能完全符合产品技术条件要求。     

Molecular weight dependence of diblock copolymer segregation at a polymer/polymer interface

Utilizing forward recoil spectrometry (FRES), we have determined the segregation isotherm which describes the interfacial excess z_i^* of diblock copolymers of poly (d₈-styrene-b-2-vinylpyridine) (dPS-PVP) at the interface between the homopolymers PS and PVP as a function of ?_∞, the volume fraction of diblock copolymer remaining in the host homopolymer. All the samples were analyzed after annealing at temperatures and times sufficient to achieve equilibrium segregation. The effect of the degree of polymerization of both the diblock copolymers and the host homopolymers on the segregation isotherm is investigated. When the degree of polymerization of the homopolymer is much larger than that of the diblock copolymer, the normalized interfacial excess (z_i^*/R_g), where R_g is the radius of gyration of an isolated block copolymer chain, is a universal function of that portion of the block copolymer chemical potential due to chain stretching. The existence of such a universal function is predicted by theory and its form is in good agreement with self-consistent mean field calculations. Using these results, one can predict important aspects of the block copolymer segregation (e.g., the saturation interfacial excess) without recourse to the time-consuming numerical calculations. © 1994 John Wiley & Sons, Inc.     

MIS系统通用插入组件的设计与实现

论述了数据字典是实现通用插入功能的关键，并描述了利用Grid控件实现通用插入组件的一般方法，着重讲述了依据数据字典动态生成界面，动态消息响应的处理过程，有很大的应用价值。     

On tolerance lattices of algebras in congruence modular varieties

We prove that the tolerance lattice TolA of an algebra A from a congruence modular variety V is 0-1 modular and satisfies the general disjointness property. If V is congruence distributive, then the lattice Tol A is pseudocomplemented. If V admits a majority term, then Tol A is 0-modular. This revised version was published online in June 2006 with corrections to the Cover Date.     

等厚双层涂层材料受集中力作用的平面问题理论解

界面应力的正确评价是分析薄膜涂层材料力学特性的难题之一。利用镜像点法和Dirichlet等值性原理，本文推导了等厚双层薄膜涂层材料受表面集中力作用的平面问题理论解。该显式理论解是以固定在各镜像点上的局部坐标系下的Goursat应力函数的形式给出的。对应于高阶镜像点的应力函数，可通过递推的方法，从对应于低阶镜像点的应力函数求得，而且也易于计算机编程。随着镜像点阶数的增大，它与界面的距离也越来越大，因而相对应的应力函数对界面应力的影响越来越小。最后的算例表明，只需考虑前面有限个镜像点，便可获得足够精度的解。该理论解可作为格林函数，以求解复杂问题的理论解，也可用作边界元法的基本解，提高数值计算的精度和效率。     

初探“微机原理与接口技术”课程的教学改革

本文简述了《微机原理与接口技术》教学中的现状和所存在的弊端,结合自身的教学体会,提出了从教学大纲、教学设计、实验项目的选取、应用能力培养等方面入手,对以往的教学进行了一些尝试性的改革,以期提高学生的学习兴趣和动手能力。     

一种高精度低功耗流水线ADC开关电容电路

提出一种新的电容失配校正方案及功耗驱动的OTA设计思路,通过对虚地电容的修正,将电容失配因子在取样保持系统中去除,达到提高电容匹配程度,降低OTA增益误差的要求,使开关电容部分的瞬态功耗下降.本文采用TSMC 0.18μm工艺设计了一个8位,取样速率为200MHz的流水线结构模数转换器作为验证电路,仿真结果说明此优化结构符合高精度和低功耗要求,可应用到流水线等高速模数转换电路中作为信号前端处理模块使用.     

排水管道系统中柔性接口质量通病分析与预防

根据张家口市主城区污水截流干管工程和宣化洋坊污水干管工程的施工经验,对市政排水管道系统中柔性接口施工质量通病进行了总结和归纳,分析了这些质量通病产生的原因,并提出了防治措施。     

计算机控制应用系统中A/D转换板的设计

在计算机控制应用系统中,模拟量/数字量接口卡是经常使用的。文章设计PCI总线的标准模拟量/数字量接口卡,可以嵌入到各种工业控制计算机的应用系统中,使应用系统的设计效率大大提高。