PGP保护电子邮件的研究

介绍了PGP对电子邮件加密和解密的工作原理过程，并从RSA算法、IDEA算法、MD5算法安全方面分研究了PGP的安全性能，研究结果表明PGP是比较好的安全软件。     

PGP——保护电子邮件的新方法

电子邮件是互联网的重要应用之一 ,它的安全性已越来越受到人们的关注。首先介绍了互联网上加密电子邮件的新软件—— PGP,具体分析了用 PGP加、解密电子邮件的详细过程 ,并简单讨论了 PGP的安全性能 ,最后分析了目前最常用的电子邮件上的 PGP加密功能。     

PGP在电子邮件安全中的应用研究

介绍了PGP在电子邮件安全中的应用,包括PGP的加密和验证原理、公钥管理方法和存在的安全隐患.     

邮件加密软件PGP的安全技术研究与应用

PGP是目前流行的邮件加密软件,它集各种安全技术于一体,具有加密强度高、加密速度快、密钥分配安全等特点。详细论述了PGP中采用的各种安全技术和实现过程,并且给出了一个在银行系统当中应用的实例。     

软交换中的一种安全策略

针对软交换中的SIP协议没有定义自身的安全机制,提出了一个可行的解决方案·简单叙述了软交换中的SIP协议的功能,特点和工作机制,并指出SIP协议中存在的安全性问题,详细分析原本为电子邮件明文的加密和签名设计的加密方法PGP(PrettyGoodPrivacy)的安全策略,加密过程,安全强度及其性能等·提出了将应用广泛、安全性高的安全策略PGP引入SIP协议中,以满足SIP消息传输中的安全要求·具体阐述了PGP在SIP协议中应用的实现方法,列举了经PGP加密的SIP邀请消息格式和用PGP数字签名的SIP消息格式·     

PGP软件系统

PGP系统是一个常用的加密软件,主要阐明了PGP用到的加密、解密算法,即IDEA单钥加密和RSA公匙加密体系,采用PGP系统就可以做到信息和加密传输,从而保证信息的安全。     

电子邮件的安全保护神-PGP安全标准

随着人们使用电子邮件的日益频繁,电子邮件的安全技术也逐渐被人们所关注。本文逐一介绍PGP涉及的经典密码算法,使读者能对PGP设计原理、安全性等有较为全面的认识。     

构筑IPv6协议下的安全邮件系统

在分析PGP协议和IPsec协议的基础上，提出一种安全邮件系统的基本结构．并对邮件传输流程进行分析，初步实现了邮件在IPv6环境下发送、接收、加密、解密、签名、验证等功能。同时，系统融合了PGP的密钥证书管理功能，为电子邮件用户提供端到端的安全服务，实现了邮件在传输过程中的保密性、完整性、发送方和接收方身份认证以及不可否认性等。     

电子邮件的安全保护神——PGP安全准则

随着人们使用电子邮件的日益频繁,电子邮件的安全技术也逐渐被人们所关注,文章逐一介绍PGP涉及的经典密码算法,使读者能对PGP设计原理、安全性等有较为全面的认识。     

PGP系统的设计实现与应用

介绍和分析了PGP加密系统主要应用到的加密原理、所涉及的算法和PGP的安全性;探讨了用C 语言编程实现PGP加密系统;最后对PGP加密系统在电子邮件中的应用及其发展前景作了介绍.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that