基本研究

In this paper, the concept of network security and security structures of OSI and Internet is introduced, and various threats confronting the computer network are also discussed. Several kinds of network information security technologies, including firewall technology, virtual private network, intrusion detection system, data encryption technology, identity authentication and security protocol etc. are also examined. The security of internal network is the biggest problem in the construction of each network. The solution to this problem lies in setting up a firewall. The theory of a firewall and the approach to its actualization is studied. Intrusion detection system, an important part of the computer network security system, has gained extensive attention. IDS monitors the computer and network traffic for intrusion and suspicious activities. It not only detects the intrusion from the extranet hacker, but also the intranet users. The emergence of virtual private network paves the way for realizing secure connection of LAN quickly and at a relatively low cost. The concept, function, key techniques, including the tunnel technology, and the ways to realize VPN are expounded in this paper. Also introduced is the data encrypt network technology, which is called the soul of computer network security, such as digital digest, digital signature, digital certificate, digital encrypt arithmetic and so on. At the same time, the principle and the process of implementing network security by digital certificate and digital signature, the basic principle and characters of security protocols, and finally, three of the security protocols, concerning the security problems in network, IPsec, SLL and SET are analyzed in detail Computer network system should be a system of dynamic defence, both dynamic and static, passive as well as active, and even offensive, combined with management and technology.

本文系统地介绍了网络安全的概念、OSI及Internet的安全体系结构，并讨论了计算机网络面临的各种安全威胁；内部网络的安全问题是每个建网单位面临的最大问题，可以认为防火墙技术是解决网络安全的一个主要手段，本文研究了防火墙的原理及其实现手段；作为一种主动的防御措施，入侵检测系统作为网络系统安全的重要组成部分，得到了广泛的重视，TDS对计算机和网络资源上的恶意使用行为进行识别和响应，不仅检测来自外部的入侵行为，也监督内部用户的未授权活动；虚拟专用网技术的出现，为实现网络间的连接提供了快速安全但又相对便宜的手段，本文较深入的探讨了实现VPN的隧道技术，并对VPN的概念、功能、实现途径、基本构成、关键技术及发展前景等问题进行了全面论述；数据加密技术是网络安全核心技术之一，本文从数据加密算法、数字摘要、数字签名及数字证书等几方面简要介绍了数据加密技术，并分析用数字证书和数字签名实现网络安全的原理和过程；对安全协议的基本原理、主要特点进行了较为深入的研究，并就网络的安全性问题剖析了三种安全协议：IPsec协议、SLL协议和SET协议。

Time is one of the basic physical attributes of the world we live in. The accurate time not only gives an essential parameter to science research and experiments and engineering technologies, but works as an indispensably ruler for all dynamics systems and sequential procedure.

时间是物质运动和存在的基本属性之一，精密的时间作为科学研究、科学实验和工程技术诸方面的基本物理参量，为一切动力学系统和时序过程的测量和定量研究提供了必不可少的时基坐标。

This dissertation discusses some basic concepts in gerontology research as well as the characteristics and theories of aging as viewed from both Western medicine and traditional Chinese medicine.

本文综述了灸法延缓衰老的研究进展和现代医学的神经内分泌衰老观，探讨了研究衰老领域中的一些基本理念，进一步对衰老的基本特征，以及其相关学说进行了描述。

The situation of the basic farmland protection in China is not optimistic, forexample: the Protecting Power of quantity is inadequate; the ignorer of quality Protectionis serious; the space arrangement is far from reasonable and so on.

论文首先介绍了国内外在基本农田保护方面的研究动态以及在国内开展本项研究的意义，然后提出了基本农田保护区规划的指导思想以及应遵循的原则。

Content of the course consists of:(1)Basic Theories of Polynomials ;(2)Linear Algebra: topics on basic matrix theory, determinant, system of linear equations, vector space, linear transformation, eigenvalue problems, inner product and Euclidean space , and quadratic form etc.;(3) Analytic Geometry: topics on algebraic operations of vectors, coordinates, lines and planes, curves and curved surfaces, etc.

学习本课程后，学生应学会用线性空间与线性变换的观点处理包括线性代数方程组在内的有关理论与实际问题；学会熟练地运用矩阵工具；本课程还学习基本的多项式知识和空间解析几何的基本知识。课程内容包括几个主要部分：（1）多项式代数；（2）线性代数：矩阵，行列式，线性代数方程组，向量空间与线性变换理论，特征值问题，欧氏空间理论，二次型等；（3）解析几何：几何空间向量代数，通过建立坐标系以及借助向量方法研究空间平面与直线及点﹑线﹑面的相互关系，借助曲面方程研究空间曲面，尤其是柱面，锥面，旋转面和二次曲面以及曲面的交线等。

Then we summarize three basic mathematical-mechanical models of granular flow dynamics: kinetic theory model, friction-plasticity model and discrete element simulation model.

首先叙述了颗粒流研究的背景和基本概念，接着概述了颗粒流动力学研究的三种基本数学力学模型：颗粒动理论模型、摩擦塑性模型和离散元模拟模型。

The research on the Yi ethnic groups and these subjects are also stick like a limpet, they promote mutually.

彝族研究学术史的基本资料和基本问题也大体清楚，并形成了自己的理论体系和研究方法。

In this paper,the existence of the nontrivial solution to a class of quasi-linear elliptic problem is investigated based on the Hardy inequality and the Mountain Pass Geometry.

使用Hardy不等式和山路几何研究了一类拟线性椭圆问题非平凡解的存在性。由于难以得到所讨论的问题的基本解，因此研究中对基本解进行了估计，并证明了c条件

This paper is based on the current research of the Pervasive Computing and Wireless sensor network.

文章第1章首先介绍了普适计算的基本概念及其研究领域，以及无线传感器网络的基本概念、特点及最新的研究情况。

The mechanism of photosensitivity and phototaxis was studied with optical andelectrophysiological method. The results are as follows:1 among three kinds of Chysopa peral. of the compound eyes show little daily change in Chrysopa sinica Tjedar .The model and color of psesudpopupil show significant daily change in Chrysopa septempzhbybimctata Wesmacl and Chrysopa formosa Brauer, color and diameter of the psesudpopupil of the compound eyes in Chrysopa septempunctata Wesmacl make rapid change at noon, afternoon ,night are similar ,but make little change in the morning and the next morning. Diameter of psesudpopupil of compound eyes is the biggest in the afternoon, which of Chrysopa formosa Brauer, is the biggest at noon.

本文应用光学及电生理学方法对棉铃虫优势种天敌—中华草蛉、大草蛉和丽草蛉3种草蛉的感光和趋光机制进行了研究，主要研究结果如下： 1、中华草蛉、大草蛉、丽草蛉复眼伪瞳孔大小、颜色昼夜间有节律性变化，且种间具有不同的变化模式。3种草蛉中，中华草蛉复伪瞳孔大小昼夜节律变化不明显，其模式和颜色上亦基本无变化，中间为一小黑点，其外围是绿色，最外层为红色，形状为正六边形：大草蛉、丽草蛉的复眼伪瞳孔大小昼夜间不同，大草蛉的复眼伪瞳孔在中午、下午、晚上变大，早晨和次日早晨基本一致，但次日早晨稍小些。

And Pharaoh spoke to Joseph, saying, Your father and your brothers have come to you.

47：5 法老对约瑟说，你父亲和你弟兄们到你这里来了。

Additionally, the approximate flattening of surface strip using lines linking midpoints on perpendicular lines between geodesic curves and the unconditional extreme value method are discussed.

提出了用测地线方程、曲面上两点间短程线来计算膜结构曲面测地线的方法，同时，采用测地线间垂线的中点连线和用无约束极值法进行空间条状曲面近似展开的分析。