改进的GMDH方法及其在参数预报中的应用

本文在综合了ＧＭＤＨ方法中几种有效的改进算法的基础上，进一步研究了变量预选及部分表达式的构成问题，采用最优化方法确定变量最佳组成式并进行变量筛选，由此得到精度更高、稳定性较好的模型，将其应用于聚丙烯熔指数的预报，仿真结果令人满意。     

An object-oriented product database using ROSE

A product database for a design and manufacturing enterprise serves as a repository for the data needed to manufacture a product. This paper discusses how an object-oriented persistent object manager named ROSE, under development at Rensselaer, has been used in the Rensselaer CIM program to develop a STEP/PDES-compliant product database for its research test bed. In so doing, it provides an overview of the requirements for a product database system in an integrated design and manufacturing facility, and it discusses how the chosen system meets these requirements.     

Production of phosphoric acid with low content of impurities

The present work is to study the possibility for controlled distribution of the impurities when they are decomposed by sulphuric acid to wet phosphoric acid and phosphogypsum, as well as generating technological conditions for production of clean wet phosphoric acid and its derivatives - phosphoric fertilizers, food phosphates and other phosphoric products.A coefficient of distribution D_A is introduced as a general criterion for elements dispersion. The study includes relationships between the weight ratio sulphuric acid/natural phosphate and D_A; the period of decomposition and D_A; the particle's size content of the natural phosphate and D_A. The obtained experimental data and relationships about the influence of the above discussed technological parameters on dispersion of more than 23 elements allow for control of that process in wet phosphoric acid and phosphogypsum by selecting specific technological conditions. Thus, depending on the requirements of acid's consumers and procedures for secondary processing of phosphogypsum to end-products, a selective decomposition of the natural phosphates to phosphoric acid and phosphogypsum can be carried out with content of the impurities in those products varying in narrow limits.     

空泡溃灭水锤的VOF计算方法

空泡溃灭水锤是核电厂冷却循环系统中较常出现的一种严重的水锤事故。空泡的形成和溃灭是复杂的两相、瞬态过程，对于这一现象的分析是相当困难的。作者尝试着把蒸汽泡的边界看成是冷水流动的自由面，在自由面上考虑蒸汽的凝结。对于自由面的ＶＯＦ算法用了ＶＯＦ算法，取得了令人满意的结果，不仅形象地描绘了空泡的形成和溃灭的过程，而且得到了与实验相符的空泡溃灭高压和弥合速度，因此可为管道设计提供理论基础。     

饲料级磷酸氢钙中氟的几种分析方法比较

本文采用茜素络合酮比色法和氟离子选择电极法对饲料磷酸氢钙进行氟的测定实验对比,得出常用的氟离子选择电极法完全可以代替经典的蒸馏比色法的结论。     

光折变晶体Cu:KNSBN的多重图像存贮实验研究

目前,光折变非线性元件在光学并行图像处理中有着非常广泛的应用。光折变晶体用于图像边缘增强,图像加、减运算,非相干—相干转换(PICOC),图像相关和卷积运算等研究已取得显著成果。本文研究了Cu;KNSBN晶体中多重图像的存贮问题,指出可以利用这种技术实现光学目标识别并给出了一些初步实验结果。此外,还从理论上分析了具有相同衍射效率的多重全息信息记录技术。     

提高涂层防腐性能评价技术的探讨

界面防腐技术是油气田三维大跨度的大型结构群体综合防护治理的主要方法之一，但我国现行的涂层检测方法还存在较大的局限性和失真度，不能反映实际工况下涂层的防护质量。文章指出了我国涂层与防护质量评价技术的现状和与国外的差距，介绍了80年代以来国外在涂层质量评价方面采用的一些新技术和先进的综合评价方法，最后提出了采用表面分析技术和电化学方法相结合的评价技术，以及对现行评价方法的再创造等建议。     

Class Based Contextual Logic for DOOD

Cntextual logic provides a mechanism to reason about modules.In this paper,this theory of modules if modules is extended to a context theory of classes where class is in the true spirit of object-oriented databases.The logic,referred to as CLOG,is class-based.CLOG supports class,object identity,multiple role of object, monotonic and non-monotonic inheritance of data and method,method factoring,views,derived and query classes.Views and derived classes are queries in themselves.Objects are pure data terms representing the ground instances of facts in the class.Object identity is a first class term in the logic.Inheritance is handled through delegation.     

造林整地排水产生水土流失及其防止措施

造林整地排水产生水土流失及其防止措施［英］Ｐ．Ａ．ＣａｒｔｉｎｇＭ．Ｓ．ＧｌａｉｓｔｅｒＴ．Ｐ．Ｆｌｉｎｔｈｅｍ１引言英国高地造林整地的常规方法是采用顺坡和横坡开沟相结合的办法进行翻耕排水。现已制订有森林排水网路的设计准则及河道管理准则，遵循这些准则...     

Scattering of waves by flaws in anisotropic laminated plates

The strip element method (SEM) is used to investigate wave scattering by rectangular flaws in anisotropic laminated plates. The plates containing flaws are divided by junctions into domains in which the SEM is applied. For each domain, SEM equations are obtained which give a relationship between the traction and displacement vector on the vertical boundaries. A set of equations which gives a relationship between the traction and displacement vector on the junctions is then obtained by assembling the SEM equations for all the domains. This set of equations is solved by using the conditions on the junctions. Scattered wave fields in the frequency domain for isotropic and composite plates with rectangular flaws are computed and discussed in comparison with results for corresponding plates without flaws. A technique for determining the length of a rectangular flaw in a plate is also presented. The results presented in this paper are of importance and could be used in the characterization of flaws in anisotropic laminated plates.