A theoretical model for mid-and low-latitude ionospheric electric fields in realistic geomagnetic fields

The geomagnetic fields, which play important roles in the ionospheric dynamo, can greatly affect the global distribution of ionospheric electric fields, currents and other ionospheric electrodynamics phenomena. In the study of ionospheric electrodynamics phenomena, such as the longitudinal variations of ionospheric electric fields, the non-dipolar component of the geomagnetic fields must be taken into account. In this paper, we deduce a theoretical electric field model for ionospheric dynamo at mid- and low-latitude which adopt a modified magnetic apex coordinates system. In the new electric field model, the geomagnetic fields can be calculated from either the IGRF model or the dipole field model, and the neutral winds and conductivities are calculated based on empirical models. Then the dynamo equation for the electric potential is finally solved in terms of the line-by-line iteration method, and the ionospheric electric fields and currents are derived from the calculated potential. Our model can reproduce the main features of the ionospheric electrodynamics processes, so it will be a useful tool for the investigation of the upper atmosphere and ionosphere.     

分数次积分算子的双权不等式

首先推广了Ｅ．Ｔ．Ｓａｗｙｅｒ关于分数次积分算子的双权不等式的几个充分条件，所得结果更加接近于必要条件Ａ然后给出了与分数次极大算子相联系的另一充分条件．     

引入青海的辽宁绒山羊双极胸导联心电图

对34只引入青海的辽宁绒山羊3个双极胸导联心电图进行了描记和分析。结果发现：①在3个双极胸导联心电图上，P波和T波的波向变化甚大；②在CⅡ和CⅢ导联心电图上，QRS综合波多数呈qR型(分别为94．2％和79．5％)，而在CI导联心电图上，QRS综合波呈现9种波型；③各波和间期的时限(s)为：P坡，0．049;P—Q间期，0．107；QRS综合波，0．059;T波，0．072;Q—T间期，0．306；Q—Tc间期，0．373;R—R间期，0．672；④被检山羊窦律不齐的发生率达64．71％。     

中日刑事强制措施制度之比较

刑事强制措施是刑事程序法的重要组成部分。但自1996年修改《刑事诉讼法》至今，由于立法观念及技术等方面的原因，刑事强制措施在立法和司法实践中暴露出许多问题。故从比较法的角度，对日本的刑事强制措施制度和我国的法制现状进行分析比较。并从我国司法实践出发，对刑事强制措施的改进提出若干建议。     

一个安全的主动网络编程语言模型

为解决主动网络安全威胁问题，从编程语言角度分析了语言级的主动网络的安全需求，使用软件机制而不是硬件机制保护主机防止恶意代码攻击，并折中了通信需求和程序语言需求，为主动网络提供了一个安全的编程语言模型。     

Preparation of organic thin-film field effect transistor

The organic thin-film field effect transistor was prepared through vacuum deposition by using teflon as di-electric material. Indium-tin-oxide acted as the source and drain electrodes. Copper phthalocyanine and teflon were used as the semiconductor layer and dielectric layer, respectively. The gate electrode was made of Ag. The channel length between the source and drain was 50 μm. After preparing the source and drain electrodes by lithography, the copper phthalocyanine layer, teflon layer and Ag layerwere prepared by vacuum deposition sequentially. The field effect electron mobility of the device reached 1.1×10ˉ6 cm2/(V@s), and the on/off current ratio reached 500.     

软件可靠性与费用权衡

软件可靠性与费用的关系是辩证的 :一方面增加可靠性可以减少软件的维修费用 ,避免软件因可靠性低不能使用所造成的开发费用的浪费 ;另一方面增加软件可靠性 ,大都以增加软件开发费用为代价 ,而软件成本的提高又制约了软件的销售和推广。对软件可靠性分配和软件测试终止时间的确定进行了深入分析 ,通过这两条途径实现了软件可靠性和费用的权衡。在此基础上 ,给出了在软件工程中权衡软件可靠性与费用的其它方法。     

汽车事故记录仪

本文提出了汽车事故记录仪的设计思想及给出了其实现电路硬件设计方案，详细阐述了汽车事故记录仪中测量刹车速度的非接触测量方法－多普勒效应测速法。并以实验装置为依据，给出了实验数据，证明了该测速法用于汽车事故记录可行性和高精度的结果。