结构优化DDDU程序系统

该程序系统由大连工学院工程力学研究所研制,1978年开始,现在已发展到DDDU-2版本。D、D、D、U是多单元、多工况、多约束、优化的汉语拼音缩写,配备杆、膜、梁等四种单元,适合组合结构在满足应力、变位、尺寸等约束下的重量最轻设计,该程序用结构化FORTRAN     

影响聚合物离子导体电导率的一些因素

本文研究了极性基团浓度、碱金属盐阳离子和阴离子尺寸对均聚物聚环氧氯丙烷(PECH)和共聚物聚环氧氯丙烷-聚环氧乙烷(PECH-PEO)电导率的影响。对锂盐络合物,极性基团浓度增高,电导率降低。钠盐络合物则正好相反,极性基团浓度越高,电导率越高。碱金属盐阳离子和阴离子尺寸对聚合物离子导体电导率都有明显影响。所研究的聚环氧氯丙烷与三种碱金属盐络合物PECH-MI(M=Li,Na,K)的电导率数据表明,钠盐络合物的电导率最高,锂盐和钾盐络合物的电导率较低。碱金属盐阴离子越大,PECH络合物的电导率越低。此外,还 关键词：     

SK_2不锈钢管式高温炉在我厂的应用

在燃烧法测定碳、硫,尽管出现了高频感应燃烧炉、电弧燃烧炉等,但因管式炉燃烧完全、碳、硫回收率高,操作简便,故障率低等优点,目前仍然得到最广泛的应用。但原来管式炉,外形简陋,易生锈变形,控温误差大、保温性能差,经常需要更换硅碳棒等原因,很难满足当前化验室发展的需要。最近,由无锡高速分析仪     

矩阵损失下带约束的回归系数非齐次线性估计的Minimax可容许性的特征

本文在矩阵损失下给出了带约束的回归系数线性估计在非齐次线性估计类中是Minimax可容许估计的充要条件。     

A NOVEL ACETYLENIC ESTER-VINYL ETHER REARRANGEMENT

A novel acetylenic ester-vinyl ether rearrrangement takes place when perfluoroacetylenicester is subject to hydrolysis with aqueous sodium hydroxide. The rearrangement is highlystereoselective and the Z-isomer predominates to the extent of above 94% in all cases. Thecrossover experiments showed that this rearrangement proceeds predominately intramolecu-larly. By using ~(18)O labeling technique and on the basis of mass spectral study, it wasshown that the rearrangement most likely roceeds through an intramolecular 1, 3 shiftof the methoxy group to the β-carbon atom. A novel mechanism involving a cage reactionin the organic phase of a two-phase system is proposed.     

Unconventional Hamilton-type variational principle in phase space and symplectic algorithm

By a novel approach proposed by Luo, the unconventional Hamilton-type variational principle in phase space for elastodynamics of multidegree-of-freedom system is established in this paper. It not only can fully characterize the initial-value problem of this dynamic, but also has a natural symplectic structure. Based on this variational principle, a symplectic algorithm which is called a symplectic time-subdomain method is proposed. A non-difference scheme is constructed by applying Lagrange interpolation polynomial to the time subdomain. Furthermore, it is also proved that the presented symplectic algorithm is an unconditionally stable one. From the results of the two numerical examples of different types, it can be seen that the accuracy and the computational efficiency of the new method excel obviously those of widely used Wilson-θ and Newmark-β methods. Therefore, this new algorithm is a highly efficient one with better computational performance.     

DV—Xa方法与电子光谱解析

本介绍了第一原理量子化学ＤＶ－Ｘａ方法在电子光谱的理论计算方面的应用。在三个例子中分别详细讨论了过渡金属原子簇的紫外－可见吸收谱Ｖ／ＵＶ、Ｘ－射线光电子能谱ＸＰＳ、和ＸＡＮＥＳ的计算,应用于ＭｏＳ４原子簇结构、Ｃｕ２Ｏ／Ｃｕ表面与２－氨基嘧啶相互作用模型、和ＭｏＳ２导带底部结构分析。根据在不同光谱分析的特点,采用相应的计算方案。电子光谱的解析除了在解释光谱现象外,能够进一步帮助了解分子或原子簇的结构。     

分散第二相γ-Al_2O_3对PEO-NaSCN络合物导电性的影响

为了获得电导率高的快离子导体,人们主要从晶格结构考虑,这在寻找银和铜的快离子导体工作中取得很大成功。然而在探索实用价值更大的碱金属离子导体时,却遇到了困难。此后,人们又把注意力转向聚合物。Fenton等人首先报导了由碱金属盐和聚环氧乙烷(简称PEO)组成的络合物,其后Armard等人研究了PEO-NaSCN的电学性能.Liang首先把γ-Al_2O_3微粒分散在离子导体LiI中,所得的固态混合物比纯LiI高约两个数量级。Weston等人在研究α-Al_2O_3对PEO-LiClO_4影响时,认为α-Al_2O_3的加入虽然增加了该离子导体的机械稳定性,但离子电导率却降低了。本文在研究PEO-NaSCN离子导体电学性能的基础上,进一步探讨了不同含量的第二相γAl_2O_3对PEO-NaSCN电导率的影响。