分子结构对增塑聚氯乙烯性能的影响

研究了聚合度、分子量分布和支化结构对增塑聚氯乙烯加工流变性能和物理力学性能的影响。结果表明，增塑ＰＶＣ的加工流变性能随聚合度的增加而恶化；拓宽分子量分布和引入支化结构均有利于加工流变性能的提高；增塑ＰＶＣ的拉伸强度随聚合度的增加而提高，而压缩永久变形却随之减小；分子量分布对物理力学性能的影响不大；支化ＰＶＣ的拉伸强度略有下降。     

An Object-Oriented Transaction Model

In object-oriented database systems(OOBSs),the traditional transaction models are no longer suitable because of the difference between the object-oriented data model(OODM)and the conventional data models(e.g.relational data model).In this paper,transction models for advanced database applications are reviewed and their shortcomings are analyzed.Exchangeability of operations is proposed instead of commuativity and recoverability for using more semantics in transaction management.As a result,an object-oriented transaction model(in short,OOTM)is presented.It is not modeled for some special application,but directly based on object-oriented paradigms.A transaction is regarded as an interpretation of a metho.Each transaction(even subtransactions)keeps relative ACID(Atomicity,Consistency,Isolation,Durability)properties,therefore the special problems appearing in OOBSs such as“long transactions”,“visibility of inconsistent database state”can be solved.     

用CT技术确定砂岩的孔隙度

周渤然等．用ＣＴ技术确定砂岩的孔隙度．测井技术，１９９４，１８（３）：１７８～１８４本文首先提出用计算机层析（ＣＴ）技术确定砂岩孔隙度的原理和方法。通过对四块人工岩样和六十块砂岩岩样的测定，其结果表明该方法是可靠的。使用ＣＴ技术可定量、定性地解释某些岩样的内部特征，重矿物分布及裂缝变化情况。实践表明，采用图象减法技术则有助于消除光束硬化现象造成的误差。     

紫草色素的研究

紫草色素原植物系紫草科Broaginaceae几种植物的根，又称紫根色素。该研究首次用人工栽培的硬紫草(Lithospermum erythrohizon Sieb.)的根，作了加工工艺和特性的研究。产品得率近1％，色价E 1^1Q5nm达150以，卫生指标符合有关规定，是种理想的脂溶性红色素。     

Experimental and mathematical studies of natural convection for solid-salt dissolution in water

The phenomena of natural convection caused by a concentration gradient usually creates currents as a result of buoyancy forces. These forces are formed from the combined effect of a fluid density gradient and the body force (gravitational force). The above phenomenon was studied experimentally in a circular glass column of 0.08 m diameter and 1 m length. This column was erected vertically and filled with distilled water with a salt bag placed on top of it and partially immersed in water. The dissolution mechanism was then modelled and a finite difference method was used to solve the formulated equations by using the implicit scheme of MacCormack (Anderson et al., 1984). The experimental results and the numerical predictions are represented graphically and give compatible agreement.     

高强IF钢析出物的析出特征

高强ＩＦ钢是汽车用深冲钢板中深冲性能最好的高强度钢板。目前，国际上对该钢种的研究十分活跃。本文在实验条件下，通过对高强ＩＦ钢析出物的观察研究了高强ＩＦ钢析出物的析出特征，发现了新的析出相ＴｉＦｅＰ，并对磷对深冲性能影响的作用机制，进行了探讨。     

无间隙原子钢的微观结构特征和塑性应变比

采用Ｘ射线衍射的ＯＤＦ和ＬＰ分析技术，ＳＥＭ电子通道花样和蚀坑技术观测，研究了超深冲无间隙原子钢板的微观结构特征。结果表明：控制化学成分、保证基体纯净、优选工艺参数，促进强的γ－〈１１１〉∥Ｎ．Ｄ纤维织构的形成是获得优异成型性的关键。用ＣＭＴＰ方法，由ＯＤＦ织构数据从理论计算了塑性应变比（ｒ），表明ｒｍ值高达３．１８。文中讨论了再结晶织构形成机制。     

MIS型单晶硅液晶光阀

详细介绍了一种新颖、快速响应的金属－绝缘层－半导体构成的MIS型单晶硅液晶光阀的结构、工作机理、制作工艺和性能参数测试。液晶采用45°扭曲向列型混合场效应工作模式。所得到的光阀的极限分辨率为40lp／mm，口径40mm，最大对比度＞100：1，在930nm（△λ＝40nm）写入光灵敏度为20μW／cm2，响应时间为15ms。报道了该光阀在大屏幕投影显示中的应用。     

一种改进的4.8kb／s码激励线性预测语音编码

本文介绍了码激励线性预测（ＣＥＬＰ）语音编码的基本原理，研究了一种制约随机激励的线性预测编码方案。它将随机激励码字进入合成滤波器的数量与自适应码本的性能指标联系起来，有效地减少了激励噪声对合成语音的影响。计算机模拟结果表明，这种方法在主观上改善了语音质量。     

Probabilistic linear models for multiresolution estimation in gray-level images

A multiresolution analysis of digital gray-level images is presented. A gray-level multi-scale framework is determined from two main assumptions: the gray scale is binary at the finest spatial resolution, and the gray levels of composed regions are obtained additively. In order to interrelate the gray-level histograms of the same image at different resolutions, probabilistic linear models are developed, which are then applied for estimation. Linear-optimization theory is used as a way of constructing such models. A general procedure for image processing is sketched, based on gray-level estimation. A versatile algorithm for nonlinear filtering is derived. Some examples of prospective applications are given.This work was partially supported by grant TIC91-646 from the DGYCIT of the Spanish Government.