螺旋管簧的可靠性优化设计

讨论了螺旋管簧的可靠性优化设计问题。在基本随机变量的概率特性已知的情况下，采用二阶矩法和可靠性优化设计方法对螺旋管簧进行了可靠性优化设计。通过计算机程序可以直接实现螺旋管簧的可靠性优化设计，迅速准确地得到螺旋管簧的可靠性优化设计信息。     

Relationship Between Coal Powder and Its Combustibility

Coal‘s volatile component ,ash and fixed carbon content have different function in different stages of a combustion process,but the traditional coal classification can precisely show its combustion property.In this experiment coal‘s evaluation indeves(ignition index Di),(burn off index Df) were used to qualitatively show the ignition property and combustion ending property of coal samples.Meanwhile,considering actual heating circumstances in calciner(in cement plants),this thesis established the relationship among the ignition index,burn off index and coal‘s industrial analysis value,which makes it possible for the user to predict the quality of coal before using it and is very valuable in practice.     

Properties of ligno‐cellulose fiber Hildegardia

Studies on some properties such as the density, the degradation temperatures, the morphology and the spectral features of the ligno‐cellulose fiber Hildegardia were carried out in both untreated and alkali treated form. The fibers are found to have good morphology and moderate initial and final degradation temperatures. On alkali treatment, the lignin was found to be eliminated. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2216–2221, 2002     

非常金猪年本本好礼送Q1

时尚与传统交织的当下,我们已经迎来12年一遇的传统农历新年--金猪年的到来,环顾大街小巷,到处都充满了喜气祥和的节日气氛,采购礼品也被提上了日程.     

透同光路指示光的CO_2激光器

报导封离型可透同光路指示光的ＣＯ２激光器的研制，并给出了其电流—工作特性曲线。对需可见光作同光路指示的ＣＯ２激光应用整机的开发，开辟了一条新的途径。     

Effect of micro-alloying titanium on the dynamic recrystallization behaviour of steels

The effect of titanium addition on the dynamic recrystallization behaviour of steels has been investigated. Constant strain rate tension tests were conducted in vacuum in the temperature range from 925 to 1225°C. Dynamic recrystallization-time-temperature (RTT) curves were developed from the flow curves at ε? = 1 × 10^?2s^?1. The results of the different steels with and without Ti indicate that the onsets of dynamic recrystallization in all the steels are earlier at higher temperatures than at lower temperatures and the addition of titanium may shift the RTT curve of the C–Mn–Si steel towards the right, i.e. retard dynamic recrystallization. The retarding effect of Ti becomes more intensive at temperatures below about 1075°C where a transition of the RTT relationship occurs. Microstructural examinations show that titanium dissolved in austenite can retard the dynamic recrystallization and the precipitation of TiC produces a more intensive retarding effect.     

GENERALIZED INVERSE GROUP OF SIGNAL AND ITS IMPLEMENTATION WITH NEURAL NETWORKS

A new concept, the generalized inverse group (GIG) of signal, is firstly proposed and its properties, leaking coefficients and implementation with neural networks are presented. Theoretical analysis and computational simulation have shown that (1) there is a group of finite length of generalized inverse signals for any given finite signal, which forms the GIG; (2) each inverse group has different leaking coefficients, thus different abnormal states; (3) each GIG can be implemented by a grouped and improved single-layer perceptron which appears with fast convergence. When used in deconvolution, the proposed GIG can form a new parallel finite length of filtering deconvolution method. On off-line processing, the computational time is reduced to O(N) from O(N2). And the less the leaking coefficient is, the more reliable the deconvolution will be.     

轴对称问题线元上分布奇点的诱导速度势和诱导速度

本文给出轴对称问题线元上高次分布源和偶极在无界域中的诱导速度势和诱导速度的计算公式,可供用分布奇点法求解轴对称势流问题时参考.     

莫来石材料的研究现状及其应用

较详细地介绍了莫来石的性能、生产、研究现状和用途。尤其对多元复合莫来石韧性陶瓷及莫来石超细粉末的制备进行了评述,同时展望了莫来石作为高级陶瓷材料的发展前景。     

应用并行技术实现CAD／CAM的高度集成

传统的CAD/CAM系统由于设计思想本身的局限性,其内部只能达到一种松散的基于数据交换的低水平的集成,产品的设计方法也不符合工程技术人员的设计思路。本文提出了基于全耦合的单一数据模型的并行CAD/CAM系统设计思想,使得CAD/CAM系统内部达到以数据共享为基础的高度集成。并行CAD/CAM系统充分体现了工程技术人员的思维方式及产品设计过程的反复性和协调性。此外,文中还提出广义参数化设计的新概念,它与特征设计方法的有机结合保证了产品模型的完整性和产品设计过程的同步性。特征共享是实现CAD和CAM集成的关键因素。并行CAD/CAM系统应用面向对象软件设计思想,实现了复杂数据模型的内部封装,并为数据模型和功能模块之间提供简单直观的界面。面向对象设计方法是开发并行CAD/CAM系统的有效手段。