较为重要

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。

Drop direction is an important parameter of drop impact ,this paper presented a new method to measure drop direction and introduced the basic structure,measurement circuit and principle of the sensor.

跌落方位是跌落冲击中的一个重要参数，测量较为困难，提出了一种基于电容传感器的跌落方位现场测试新方案，分析了其基本结构、测量电路、测试原理和方法。

Finally, it points out that emulation system is a very important assistant measure for comprehensive experiments.

最后指出通过软件仿真来完成较为复杂的综合性实验是一种重要的辅助手段。

In short, in the impact of ultra-high Falsework ultimate strength of the three main factors, in regard to the first factor, has conducted a comprehensive study structural measures had some quantitative and qualitative research results and the third most important factor, But there are many studies to be done.

总之，在影响超高模板支架极限承载力的三个主要因素中，关于第一个因素，已进行较为全面的研究；构造措施方面有了一些定量和定性的研究成果；第三个因素最重要，但还有许多研究工作要做。

In this paper,the development of non-linear analysis approach,a more detailed presentation of the finite element software ADINA and ANSYS in the reinforced concrete structure,step by step analysis of a reinforced concrete structure of the finite element analysis techniques and the use of commercial finite element analysis software for concrete the structure of the two most important components-beams and columns of the comparative study of performance analysis.

本文从非线性分析的发展入手，较为详尽的介绍了有限元软件ADINA和ANSYS在钢筋混凝土结构中的应用，逐步分析了钢筋混凝土结构的有限元分析技术，并且利用商业有限元分析软件对混凝土结构中最重要的两类构件——梁和柱的性能进行了对比研究分析。

Geomancy is a special culture phenomenon in ancient China and has an important influence on the theory of ancient novel techniques.

堪舆是古代一种较为独特的文化现象，它对古代小说技法论产生了重要影响。

Golden Eagle fund companies are more optimistic point of view, they believe that the current layout of the next two years is an important stage of investment.

金鹰基金公司较为乐观的观点，他们认为，未来两年当前的布局，是投资的重要阶段。

In some way, the nature of the geochemical field shows that the deep fluid took part in the energy mineral reservoir formation and mineralization.2、 In zones with the strong tectonic activity and basement faults, the elements combination of petroleum is complex and the material from deep resource can be found in which. The character of elements geochemical and carbon isotope all show that there are deep fluid components in some Energy Minerals. The material source of the water accompanying with petroleum reservoir is complex, and which with multi-sources. The character of elements geochemical shows that the uranium of Dongsheng uran ore comes from the upper crust, the greyish-green gritstone and hoary kaolinised argillaceous siltstone is important for the formation of uranium deposits,and the grey gritstone is great potential to surveying uranium deposits .

基底断裂带和构造活动强的区域，原油中元素组合复杂，并含有深源物质；元素地球化学特征和同位素特征反映部分能源矿产中含有深部流体成分；盆地内油气藏伴生水的物质来源较为复杂，具有多源性；元素地球化学特征显示东胜铀矿的铀源主要来自上地壳，灰白色高岭土化泥质粉砂岩及灰绿色粗砂岩对铀矿的形成具有重要的意义，灰色粗砂岩具有良好的找矿潜力；元素地球化学特征还表明，黑岱沟煤及煤层夹矸中微量元素来源于上地壳。

Six standards are explained clearly. It is important to heighten the level of expressway construction and management.

通过对"六化标准"进行较为明晰的阐述，对不断提升高速公路建设管理水平具有重要的作用。

Therefore, before China join WTO, it has important theoretic significance and great practical value to systematically study horizontal merger under open economy.

因此，在中国加入WTO的前夕，对开放经济下企业横向兼并中的问题进行较为系统的研究，显然具有重要的理论意义与现实价值。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。