基于整数规划的特殊永磁型磁体匀场技术的改进研究

本文针对磁共振成像（MRI）系统成像对磁体的要求，提出了一种基于整数规划的无源匀场数学模型。按照实际匀场时以测量平面的中心场值为参考基础，改进了原有的模型，进行了匀场模拟。匀场结果表明，该方法能快速有效地完成匀场过程。     

Two new Jurassic stoneflies （Insecta： Plecoptera） from Daohugou,Inner Mongolia,China

Two new genera and two new species of family Taeniopterygidae, Mengitaenioptera multiramis gen. et sp. nov. and Noviramonemoura trinervis gen. et sp. nov. are described. These fossils were collected from Daohugou Village （the Middle Jurassic）, Inner Mongolia, China. Hitherto, these fossil species from Daohugou are the oldest taeniopterygids. Both simple and complex venations simultaneously occurred in this group, which reveals that the early diversification of taeniopterids was well underway by the Middle Jurassic. Therefore, we prefer to adopt the Comstock＇s opinion that the venation of taeniopterids was derived from the simple venation of the older group （such as Palaeonemouridae） at much ancient geological time ago. Some of the descendants carried this simple venation; others evolved into complex venation with many additional crossveins and branches.     

关于住房公积金制度的思考

住房公积金制度是我国住房制度改革的重要内容。通过分析住房公积金制度运行以来出现的问题，提出了相关对策。     

昆虫兴盛不衰的原因再探讨

根据现代昆虫学研究成就 ,就昆虫兴盛和久盛不衰的原因进行了再探讨 .遗传基础的稳定性、可变性 ,环境条件的变化 ,微小的体形 ,运动方式、能力、食性、繁殖 ,变态 ,休眠及生存空间等特点成为其久盛不哀的主要原因     

公路沥青路面早期破坏原因的浅析

随着对沥青路面的使用不断提高,新建公路早期破坏的问题也越来越受到道路工程者的重视。本文从路面设计、路面施工、养护管理及其它环节等方面,结合自己工程实践,分析了沥青路面早期破坏的原因,可为预防沥青路面早期破坏提供参考。     

求解大型稀疏线性方程组的广义AOR迭代法(英文)

基于一种新的更一般分裂,文章提出求解大型稀疏线性方程组的广义AOR迭代法,它的显著特征是更易于执行并行计算.进一步,AOR方法的一些性质相应地推广到了新方法中.最后,用数值例子验证了新方法的优点.     

Photoconductivity of [60]fullerene derivatives

Two [60]fullerene derivatives (compounds 1 and 2) have been synthesized. Their redox properties have been measured by cyclic voltammetry. The photoconductivities of poly(N-vinylcarbazole) (PVK) doped with [60] fullerene and with their derivatives have been studied to explore the possible relationship between the reductibility of fullerenes and the photoconductivity of fullerenes-doped PVK. The charge generation efficiencies of PVK doped with [60]fullerene and with its derivatives have changed remarkably: the diversity of charge generation efficiency is obvious in different doping systems. The result indicates that there is charge transfer between fullerenes and PVK.     

辽河盆地与伸展作用有关的构造运动学分析

辽河盆地是中生代大陆内裂谷盆地，以伸展作用为主，同时受到后期走滑作用的改造，构造形式复杂。裂谷盆地的形成、演化是在伸展活动发生复杂而有规律的运动中进行的，表现为水平伸展运动、垂直升降运动、掀斜或翘倾运动等，这是裂谷盆地的主要特征。该盆地的各时期掀斜角度不同造成凹陷的差异性，限制了沉积生油岩的范围，从而决定着油气资源分布。     

功率MOSFET驱动电路探讨

针对功率ＭＯＳＦＥＴ的特点．介绍由多个三极管组成的组合式驱动电路．在逆变焊接电源上做了实验．验证了该方法的合理性．     

无穷多个函数的随机动力系统

本文考虑无穷多个函数的随机动力系统，并研究这种动力系统的动力学性质。