大气中子单粒子效应对微电子器件的影响

本文对中子单粒子效应的产生条件、中子单粒子效应对微电子器件的影响以及对此影响的量化分析过程进行了阐述。主要通过分析结果,给出微电子器件受中子单粒子效应影响的薄弱环节,同时给出设计改进措施,通过改进措施提高电路设计水平,保证微电子器件在使用过程中的可靠性。     

中子单粒子效应试验对机载应答机的影响

为了获取大气中子单粒子效应对机载电子设备的危害程度,本文以航空应用领域的机载应答机为例,以应答机处理模块为中子单粒子试验对象,从开展试验的试验方法,试验现象,试验结果等方面,研究中子单粒子对机载应答机的影响。     

单层不等高厂房横向抗震效应调整系数的探讨

《建筑抗震设计规范》(GB 50011-2001)在附录H给出的表H.2.3-1钢筋混凝土柱考虑空间工作和扭转影响调整系数并不适用于底部剪力法,为此经过大量的实例计算,采用数理统计的方法,给出了适用于底部剪力法的效应调整系数,可供单层不等高柱钢筋混凝土厂房横向抗震计算参考。     

单层不等高厂房横向抗震效应调整系数的探讨

《建筑抗震设计规范》(GB50011-2001)在附录H给出的表H.2.3-1钢筋混凝土柱考虑空间工作和扭转影响调整系数并不适用于底部剪力法,在经过大量的实例计算,采用数理统计的方法后,给出了适用于底部剪力法的效应调整系数,可供单层不等高柱钢筋混凝土厂房横向抗震计算参考。     

单桩计算的一种理论方法

通过对单桩及桩周土层的离散化处理,将单桩体系分割成两部分进行研究。其中:桩周土层采用Mindlin应力解和修正分层总和法计算其任意点处的应力场和变形量;而桩体本身则根据荷载传递方法计算其荷载变形关系。两部分之间通过荷载、变形协调关系建立联系,并采用迭代法求解。本文方法既能计算单桩荷载传递又能预测单桩变形特性。算例结果表明:本方法有较高的计算精度。     

几种单跨框架结构设计方案的比较

结合单跨连廊框架实际工程,采用PKPM系列软件的SATWE软件,对设置框架柱、设置剪力墙和设置钢斜撑的单跨框架结构方案进行了分析比较,分析表明:采用设置钢斜撑的单跨框架不仅能满足建筑立面的要求,且能改善单跨框架的受力性能,是一种比较合理的结构方案。     

多一单自由度体系等效转换的若干问题的探讨

提出等效单自由度体系的概念,阐述了等效的前提条件,叙述了两大不同的等效模式,着重分析了不同侧移模式和水平荷载分布模式对等效体系建立的影响,指出等效参数求解中存在的问题,最后对框架结构的等效转换简化计算提出建议,并对适用的计算方法作出探讨。     

沉积岩的一种时间效应模型

提出沉积岩的一种时间效应模型。沉积岩的固有各向异性用一个标量各向异性参数描述,引入一个损伤因子来考虑时间效应,材料的单轴抗压强度是时间、微结构张量和应力的函数。建立了一个描述各向异性沉积岩变形过程的全塑性模型。用提出的模型对一些试验进行了模拟,结果表明该模型能有效地描述沉积岩的固有各向异性及其时间效应。     

一种森林灭火弹的终点效应分析

在灭火弹的动态试验中,通过对炸点处灭火剂抛撒过程的观察分析,归纳出影响灭火弹终点效应的因素,研究爆轰角和起爆深度的大小与灭火剂抛撒云团的关系,认为爆轰角过大时,灭火剂不能有效作用到火焰根部;起爆深度过深时,灭火剂抛散在土壤中,都会影响灭火效果。     

考虑土体剪胀的静压单桩挤土效应

在大型通用软件ANSYS平台上对静力压桩的连续贯入的全过程进行有限元模拟，给出了土体剪胀对挤土位移及应力的影响规律。利用位移贯入法使桩体贯入，考虑了弹塑性本构关系、自重应力场、大变形和桩-土滑动摩擦等复杂问题，更符合静力压桩的实际，具有仿真效果。     

一种塔式起重机自动倍率转换装置的设计

阐述了塔式起重机现有的倍率转换方式,分析了现有方式的优缺点.提出了一种结构简单的新型自动倍率转换方法,并建立倍率转换结构关键部位的接触曲线模型,保证了此倍率转换的平稳性.     

基于面向对象的单元自动化测试工具研究

阐述了面向对象系统中单元测试的概念，针对面向对象的单元自动化测试给出了理想的自动化测试工具体系结构，并对在理想状况下如何实现自动化的相关问题进行了探讨，以实现完全自动化。     

GIS数据库更新信息自动传播软件工具设计与实现

针对现有GIS软件工具缺乏相应的功能模块,不支持批处理,需要大量的人机交互,不能满足GIS数据库更新信息传播自动高效要求的缺陷,采用ArcEngine组件技术设计实现了一个专门的更新传播工具。该工具通过自动地执行更新传播过程中的模式匹配、变化提取、更新集成等操作,能够有效地提高更新传播的效率,弥补现有软件的不足。     

Shear-induced conversion of seismic waves across single fractures

Elastic wave conversions across a fracture in rock subjected to shear stress are observed during laboratory ultrasonic transmission tests. Compressional waves (P-waves) and shear waves (S-waves) normally incident on a sheared fracture are partially converted to waves with particle motions that are not present in the incident waves. The amplitudes of the converted waves increase significantly with increasing shear stress applied to the fracture. The particle motion of the converted wave changes its phase by 180° when the direction of the shear is reversed. These wave behaviors can be explained by adding the coupling (dilational) components in the fracture stiffness matrix of the displacement–discontinuity boundary conditions for a non-welded interface. The shear-induced wave conversion presented in this paper has a wide range of potential applications for monitoring and determining the magnitude of shear stress acting on fractures in geologic and engineered materials.     

自动换刀装置在中小型立式加工中心的应用

介绍了自动换刀装置在中小型立式加工中心的应用,简要归纳了自动换刀装置应当满足的基本要求,并研究了刀库及机械手的确定问题,给出了具体应用时的控制方案和实施步骤,通过增加自动换刀装置,节省了时间,提高了加工效率。     

面向情感语音转换的韵律转换方法

面向情感语音转换,该文提出了一种韵律转换方法。该方法包含基频转换和时长转换两个部分,前者选择离散余弦变换(DCT)参数化基频,根据基频的层次结构特点,将基频分解为短语层和音节层两个层次,使用基于混合高斯模型(GMM)的转换方法对两个层次分别进行转换;后者使用基于分类回归树(CART)的方法以声韵母为基本单位对时长进行转换。一个包含三种基本情感的语料库用作训练和测试,客观评测以及主观评测实验结果显示该方法可有效进行情感韵律转换,其中悲伤情感在主观实验中达到了接近100%的正确率。     

A decision support system for conflict analysis on environmental effects of energy conversion

Environmental aspects play an important role in the complex decision process of energy production.In this article we describe an Environmental Assessment System (EASY) that functions as a decision support system to actors or groups of actors involved in the decision process.The system contains two dimensions: one for information processing and one for evaluation. The information processing dimension deals with the representation of real world phenomena by means of impact analysis (cause-effect chains). The evaluation dimension deals with evaluation of a set of alternatives at each level of the cause and effect chain. The potentials for use of EASY in situations of conflict between (groups of) decision makers are discussed by means of two examples.     

Analysis, synthesis and simulation of fire signals as a tool for the test of automatic fire detection systems

A simulation method for the test of one input fire detection algorithm is presented. A signal model is described, capable of synthesising time variant random signal sequences with similar statistical properties, as observed for signals of smoke- and temperature-measuring devices in reality. The time varying model parameters are derived from recorded signals in realistic environmental conditions. The necessary analysis method is discussed.

The simulation method is equally well suited for synthesising signal sequences in the ‘fire-’ and ‘nonfire’ case, which is necessary for the detectivity test of a detection algorithm. A fast transputer implementation yields acceptable calculation times even for estimates of the false alarm rate, corresponding to years observation time in reality.     

The radiative effects of building groups on single structures

The role of building group configuration in controlling the heating and cooling abilities of structures is considered. A computer model is described which simulates the thermal stresses of simple building groups composed of identical structures. The natural heating of the structures is measured as a function of the daily exposure of individual structures to direct sunlight. The cooling of structures is measured as a function of their sky view factor. Building groups are compared in terms of these measures at different latitudes and times of the year. The results show that group design can have a significant impact on the thermal stresses experienced by individual buildings.