Delay systems and optimal control

0. IntroductionIt is well known that evolution systems are an important class of distributed parametersystems and the optimal control of infinite dimensional systems is a remarkable subjectin control theory. Some authors including us investigated the existence of solutions orperiodic solutions (see [l--4] or [5,6] ). To the knowledge of the authors, optimal controls fordistributed parameter delay systems have not been extensively studied. Li and Yao obtaina maximum principle (see [7]). Here w…     

C(3P)与H2S反应的反应机理

The mechanisms of the C(3P)+H 2S→HCS+H and C(3P)+H 2S → HSC+H reactions have been studied at the UMP2/6-31G(d,p),UMP2/6-311G(d,p),and G2 levels, and six transition states and three intermediates have been located along the reaction paths. The predicted path for the C(3P)+H2S→HCS+H reaction is: C(3P)+H2S→IM1→TS1→IM2→TS4→HCS+H, in line with the reaction process suggested by Lee et al. [1] in which only the intermediates were given. Our energetic results indicate that the C(3P)+H2S→HCS+H reaction is more favorable than the C(3P)+H 2S→HSC+H reaction, in agreement with experiment.     

跨国公司与化学

跨国公司是现代企业发展到国际化生产的产物 ,是世界商品的重要生产者 ,它在激烈的世界性竞争中 ,不断地进行科学研究及技术开发 ,大大推动了世界科技革命进程。在化工领域 ,跨国公司利用自身的经济实力及技术力量为化学基础理论、化学工业的发展作出了巨大的贡献。     

考虑三轴约束时孔洞的聚合机理及有效能量准则

通过体胞分析方法,对不同状孔洞在从光滑试样到裂纹试样的三轴应力场中的聚合机理进行了较精解的有限元分析,计算结果表明：（１）孔洞的相互靠近和横向扩展是导致相邻孔洞发生内颈缩聚合的两种基本机制,在应力三维度Ｒσ等于１．２５附近,这两种机制发生较明显的变化。（２）单纯以孔洞体积分数ｆＣ概念为基础的材料破坏参数一般敏感于应力三维度,不能很好地预报不同三轴应力场中材料的破坏,在此基础上,提出了描述孔洞聚合的     

Wavelet Rational Filters and Regularty Analysis

In this paper, we choose the trigonometric rational functions as wavelet filters and use them to derive various wavelets. Especially for a certain family of wavelets generated by the rational filters, the better smoothness results than Daubechies' are obtained.     

芳香氮化物-CHCl3系列复合物密度泛函法研究

报道对芳香氮化物吡咯(C4H5N)、苯胺(C6H5NH2)、对位氯代吡啶(C5H4NCl)、吡啶(C5H5N)及吡咯负离子(C4H4N-)与三氯甲烷(CHCl3)形成的系列弱作用复合物的理论计算结果.把复合物看作是一个超分子,在密度泛函B3LYP/6-311G(d,p)的水平上进行计算,探讨该系列复合物的稳定性规律、电荷转移及主要几何参数变化等规律.计算结果表明:此类芳香氮化物与三氯甲烷(CHCl3)可形成一系列弱化学作用复合物,特别是带负电荷的芳香氮化物可与CHCl3形成较稳定的复合物.形成复合物的过程包含着电荷转移,该系列复合物的稳定性与广义H键距离的变化规律相一致,与电荷转移量的变化规律大体一致.     

钌(Ⅲ)-二安替比林对氯苯甲烷-高碘酸钾体系催化分光光度法测定痕量钉

在磷酸介质中及加热条件下,钌（Ⅲ）对高锰酸钾氧化二安替比林对氯苯基甲烷（ＤＡｐＣＭ）显色反应有强烈的催化作用,由此建立了测定痕量钉的方法。体系的最大吸收波长为 ５００ ｎｍ,钌的含量在 ０．０～４．０μｇ／Ｌ范围内具有线性关系,检测限为 １．９４×１０－１０ｇ／ｍＬ,反应的表观活化能为 ８８．２０ ｋＪ／ｍｏｌ,反应表现速率常数为 ７．７ ０×１０－４／ｓ。本方法用于矿样中痕量钌的测定得到了满意的结果     

加强实验教学研究 培养学生创造思维

化学教学中实施创造教育,要特别加强实验教学研究.本人的做法是挖掘实验教学与创造思维培养的结合点,诱导学生创造思维;创设教学氛围,激发学生创造思维;加强实验创新,训练学生创造思维.     

二次谐波共焦成像的分辨率

通过与双光子荧光共焦成像过程比较,研究了非线性二次谐波的强度脉冲响应函数并对它进行频域分析,获得了横向、纵向截止频率和通频带.研究结果表明：二次谐波共焦成像具有更高的分辨率.     

Approximate Methods for Generalized Inverses of Operators in Banach Spaces

In this paper, we present the necessary and sufficient condition of convergence of several iterative methods for computing the generalized inverses of operators in Banach spaces. It is proved that the iterative methods converge to the generalized inverse of an Operator in Banach spaces if and only if these conditions are satisfied.