防御

Based on wake features and operational principle of wake homing torpedo , this paper introduces some methods of soft kill , hard kill and non-kill ,such as gas generator , magnetic wake , torpedo net defense , depth bomb , anti-torpedo torpedo , stealth , and evasive maneuver. We summarizes three key points in the defense against wake homing torpedo , including high perfo口nance torpedo alarm system , rapid response acoustic countermeasure system , and multi-functional acoustic countermeasure device , to provide approaches to effectively countering wake homing torpedo.

该文基于尾流特征及尾流自导鱼雷工作原理介绍了用于对抗尾流自导鱼雷的气幕弹、磁尾流、拖网、深水炸弹和反鱼雷鱼雷等几种软杀伤和硬杀伤方法以及隐身技术和机动规避等非杀伤方法总结了舰船对抗鱼雷攻击3 个的关键环节包括高性能鱼雷报警系统、快速反应的水声对抗系统和多功能的水声对抗设施旨在为有效防御尾流自导鱼雷提供思路。

If defense is not possible, deterrence is generally the next priority.

如果防御不可能，那么威慑通常是下一个优先目标。

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。

This paper introduces how to make use of a reasonable construction craft to improve the defence abitity of dike .

文章介绍利用合理的施工工艺来提高堤防的防御能力的方法。

The purpose of the fence is to keep out a kind of wild dog called a Dingo.

篱笆的作用在于防御一种叫"澳洲犬"的野狗。

Now I make it clear that this system is directed at preventing a potential attack from Iran .

现在我在这里明确表示这个系统意在防御伊朗的潜在威胁，与俄罗斯没关系。

Thus, it is likely that shedding is mediated both by proteases and by disassociation of the non-covalent interaction between the α- and β-subunits.

研究人员在胃部发现一种命名为MUC1的蛋白质，该蛋白质能够对幽门螺旋杆菌的起到防御作用。

The electric organs, composed of modified muscle tissue, are in the disk near the head.

发电器一对，由变态的肌肉组织构成，位于体盘内，头部两侧，用于防御和捕获猎物。

The electric organs, compose d of modified muscle tissue, are in the disk near the head.

发电器一对，由变态的肌肉组织构成，位于体盘内，头部两侧，用于防御和捕获猎物。

Superoxide dismutase (EC 1.15.1.1;SOD) is a metal-containing enzyme that widely exist in organisms. It catalyzes the dismutation of superoxide free radical and produces hydrogen peroxide and oxygen.It plays an important role in protecting the plasmalemma from the reactive oxygen species.A recombinant plasmid pPICZA-sodM18 was constructed and after its linearization was transferred into chromosome of Pichia pastoris GS115 by electroporation.

超氧化物歧化酶(Superoxide dismutase；EC 1.15.1.1；SOD)是广泛存在于生物体内的金属酶，是机体内唯一以超氧阴离子自由基(O_2~-)为底物的酶，它能专一地催化O_2~-的歧化反应，生成过氧化氢和氧气，能有效的抵御氧自由基和其他氧化物自由基对细胞质膜的毒性，对机体防御氧化损伤起着十分重要的作用。

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。