如何解决在UNIX下忘记超级用户口令

超级用户的口令存放在etc/passwd,/etc/shadow和tcb/files/auth/u中，通过设置其EncryptedPassword项为空，则UNIX将迫用户在下次注册时重新输入的口令。     

WEB上用户口令的安全传输

主要阐述了利用MD5加密算法来保证WEB上用户口令的安全传输。首先用MD5对用户口令进行一次加密，然后再用MD5对该密文和一个随机数组成的信息进行加密，形成网络上传输的用户口令，实际上用户的原始口令没在网络上传输，从而保证了用户口令的安全。     

NETWARE超级用户口令的安全管理

超级用户口令的安全性,是直接影响整个NETWARE网络系统可靠性与稳定性的重要因素。利用NETWARE自身特性及外部程序,提出有关系统超级用户口令安全管理的一些方案。     

计算机校园网的安全管理

我院即将使用新的校园网，校园网应注意信息的保密，网络管理员及用户均应加强安全意识，并特别注意保护自己的服务器和自己的口令。     

基于动态软键盘和随机码的Web口令安全传输

在无线网络中,为防止用户口令被窃取,提出一种Web口令安全传输方法。在Web门户中显示局部动态软键盘,同时加入随机码,通过消息摘要算法(MD5)将用户口令与随机码进行加密,然后发送。实验结果证明:该方法可以防止黑客通过接入点截获用户口令、重放攻击和暴力破解;与已有Web口令安全传输方法相比,计算复杂度低,效率、安全性和可信度高;可以有效防止终端攻击和网络攻击。     

C/S环境下动态维护Oracle用户口令方法探讨

针对在 Client/Server( C/S)模式下 ,客户端应用程序与服务器端数据库的连接方式给数据库安全带来的问题 ,分析了 Oracle DBMS所提供的安全机制 ,在 Powerbuilder与 Oracle连接方式的基础之上 ,提出了一种动态维护 Oracle数据库用户口令的方法     

Linux安全用户管理机制的设计与实现

传统Linux本地用户管理中存在一些安全问题,例如由于用户信息管理由应用层实现,导致密码文件/etc/shadow只能由root访问和修改,为了让普通用户能修改自己的密码等需要特权的操作引入set uid/set gid机制,结果 set uid/set gid程序存在缓冲区溢出漏洞使系统遭受严重安全威胁.为此我们设计出一种新的安全用户管理机制,在内核中管理用户信息,通过系统调用提供用户信息访问和身份切换服务,消除set uid/set gid,简化安全设计,提高系统安全.     

基于单向散列函数的智能卡鉴别方案

提出了一种在智能卡中实现的基于单向散列函数的远程身份鉴别方案，用户能自己选择口令并且系统不需要维护任何与用户口令相关的信息，系统中用户不受限制，用户利用智能卡以及口令便可成功地登录到远程系统，攻击者不能从公开或传送的信息中获得用户秘密信息，也不能冒充别的合法用户，此外，本方案还能抵抗登录请求的重播。     

一次性口令技术的研究

Lealie Lamport一次性口令认证方案是一种著名的口令认证方案，但存在不足之处：如果用户想为远程系统重新生成口令链，或为新的远程系统生成口令链，则必须再次到特定的系统注册，这很不方便，也不灵活．为解决该问题，提出了一种初始化和修改一次性口令的方案。     

一种基于打分机制的文本相似度匹配算法

本文借用语音识别技术读取用户输入口令,对用户口令和机器指令分别进行分词处理并建立字典向量,字典向量都以用户口令中的文字作为键所以具有相同的维度,在向量的基础上对用户口令和机器指令进行夹角余弦计算以实现对机器指令的第一次打分;第二次打分则是在第一次打分的基础上进行,因为如果当用户口令和机器指令在所包含文字上已经相似,则有必要对文字的排列顺序做一个考察。本文通过提取用户口令中文字的关系对并与机器指令相比较的方式对机器指令进行一个顺序打分,最终挑选出文字与排序都与用户口令最相似的机器指令。     

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.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

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-