Linux下Apache服务器的扩展

Apache是一种提供网页快速浏览的服务器软件.Apache的提供的功能服务有限,若要支持一个多功能的网站浏览则需要与tomcat,helix等一些服务器软件的配合.本文以软件安装与设置的操作为例,来分析在Linux系统下Web服务器和流媒体服务器的如何架设.在此例子中,Web服务器软件采用的是apache与tomcat的整合,流媒体服务器采用的是Helix流媒体服务器.在此笔者阐述了,在Linux系统下多种服务器架设所遇到的问题及其相应措施,并以实际例子展示Linux系统下的服务器架设.     

浅谈基于国产Linux的NC机的应用

<正>目前,越来越多的网站、政府部门、学校等部门、 单位采用Linux操作系统,提供邮件、Web、文件存 储、数据库等服务。也有非常多的公司在企业内部 网中利用Linux服务器提供这些服务。随着人们对 Linux服务器依赖的加深,对其可靠性、负载能力和 计算能力也倍加关注。有关国产linux的出现和应 用,大家更是众说纷纭,而且市面上出了很多版本的 国产linux,例如:红旗、中软等,到底哪一个好用,其 实主要是能达到使用者的目的就行了。这次我们采     

Linux环境下的Web服务器负载均衡技术初探

利用虚拟服务器技术实现Web接入负载均衡就是利用软件实现多机协同工作以完成同一重载服务的一项新兴技术。而这一技术近年来在Linux中也发展得较为活跃。本文探讨了在Linux环境中的几种常用的虚拟服务器负载均衡模式和调度算法。     

Web服务的多层入侵容忍机制

Web服务通过互联网向公众提供各种服务,其存在的漏洞容易受到攻击.攻击会导致许多恶意操作或故障,致使Web服务器无法正常工作或发生安全事件.确保服务器的安全性,以保障系统数据和服务的私密性、完整性及可用性.Web服务的多层入侵容忍机制,结合传统安全技术和容忍技术在服务器前和在服务器结构内部署不同传感器,侦测各请求对服务器的影响.对不同安全级别的请求提供相应的服务,并一定程度上容忍非正常请求的存在.在Web服务系统上提供有效的深度防御,提高Web服务器对入侵、攻击的适应能力,即使发生严重事件也能及时恢复Web服务.不会因存在入侵、故障而停止服务,从而提高Web服务器的生存能力.     

趋于云计算的虚拟服务器集群

采用Vmware虚拟化方法将计算资源虚拟化,成功切割了硬件的计算和存储能力,通过合理配置建立在虚拟硬件资源上的Linux虚拟服务器集群,实现了云端计算的高可用和负载均衡.该集群不仅可以提供传统的Web、Ftp等服务,也可以提供可完全配置权限的操作系统租用服务.     

基于嵌入式Linux的DM9000的网络驱动

嵌入式网络技术正在快速发展,基于嵌入式的网络开发和应用成为当前研究热点.以嵌入式Linux为载体的DM9000网卡是通信领域应用较为广泛的硬件设备,因此开发DM9000网卡的驱动程序具有现实意义.本文基于嵌入式ARM和网络芯片DM9000对网络驱动程序进行研究,分析Linux网络驱动的实现原理,实现了基于嵌入式Linux的DM9000的网卡驱动程序开发,通过对应用程序服务器和客户端的设计,进一步分析网络驱动的工作原理,为更好地利用和改进网络驱动提供理论依据.     

一个大容量邮件服务器的Web Mail系统的设计与开发

提出在 Linux上以 Postfix为 SMTP、 Cyrus为 POP/ IMAP服务器、 Apache为 Web服务器和 My SQL为后台数据库构建一个支持大量用户的邮件系统 ;利用 Java技术实现此邮件系统的 Web Mail服务     

Linux下动态Web服务器平台的搭建

介绍了在Linux环境下用Apache、PHP和MySQL搭建能够提供动态网页支持与数据库服务的Web服务器平台的方法。     

基于Linux的嵌入式Web服务器网络协议栈的设计

在分析Linux网络系统实现机制的基础上,对当前各种常用Linux协议栈的添加方法进行了深入研究,提出了一种Linux环境下嵌入式Web服务器协议栈S-TCP/IP的裁减方案,该方案利用Linux网络系统结构中的抽象接口和数据结构定义中的自定义结构项,对Linux中TCP/IP协议栈和IP协议进行裁减,并在Linux中添加S-TCP/IP协议栈.该嵌入式网络协议栈应用于Web服务器,实现了对Web服务器的访问.     

基于 ARM 11的嵌入式 Web 服务器设计与应用

随着网络技术与嵌入式系统的快速发展,嵌入式设备在远程管理、监控领域的应用越来越普及.由于嵌入式Web服务器成本低、体积小、功耗低、使用方便等特点,且实现了嵌入式技术与网络完美结合,故嵌入式Web服务器技术也逐渐成为嵌入式技术应用领域中的一项关键技术.在OK6410开发板上,设计与实现了Linux操作系统下的嵌入式Web服务器,并经测试表明Web服务器稳定,反应迅速,使用方便,故具有很好的应用前景.     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

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-