排序方式: 共有71条查询结果,搜索用时 31 毫秒
31.
代理服务器的研究与实现 总被引:2,自引:1,他引:2
代理服务器作为连接Internet与Intranet的桥梁,在实际应用中发挥着极其重要的作用。它可用于多个目的,最基本的功能是连接,此外还包括安全性、缓存、内容过滤、访问控制管理等功能。文中实现了一个代理服务器系统,可代理HTTP,FTP,TELNET,SMTP,POP这五个常用协议,此外还有用户管理和拨号等功能。该系统已完成了一系列功能测试,已在网上运行,能稳定地代理各类Internet访问服务 相似文献
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本文介绍了在PowerBuilder7.0环境下利用窗口的定时事件(Timer)和系统的定量函(Timer())相结合的形式实现倒计时功能,以及调用Windows函数实现自动关闭窗口重新启动计算机的方法,并应用于上机考试软件中。同时论述了在上机考试过程中,当出现死机现象时,实现累计倒计时的方法。 相似文献
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详细介绍了可以在政府部门和各企事业单位应用的网上考试系统的开发过程和工作原理,简要介绍了该系统的主要优点,主要应用的开发工具是VS.NET2003与SQLServer2000,采用了Browser/Web模式和ADO.NET技术。详细介绍了该系统各个部分的功能和其工作方式以及数据库的设计。本文针对传统考试的多种不便,阐述了网络考试方式的设计方法,尝试解决传统考试中的一些缺陷。 相似文献
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Gerard J. M. Versteegh 《Space Science Reviews》2005,120(3-4):243-286
The nature of the climatic response to solar forcing and its geographical coherence is reviewed. This information is of direct
relevance for evaluating solar forcing mechanisms and validating climate models.
Interpretation of Sun-climate relationships is hampered by difficulties in (1) translating proxy records into quantitative
climate parameters (2) obtaining accurate age assessments (3) elucidating spatial patterns and relationships (4) separating
solar forcing from other forcing mechanisms (5) lacking physical understanding of the solar forcing mechanisms. This often
limits assessment of past solar forcing of climate to identification of correlations between environmental change and solar
variability.
The noisy character and often insufficient temporal resolution of proxy records often exclude the detection of high frequency
decadal and bi-decadal cycles. However, on multi-decadal and longer time scales, notably the ∼90 years Gleisberg, and ∼200
years Suess cycles in the 10Be and 14C proxy records of solar activity are also well presented in the environmental proxy records. The additional ∼1500 years Bond
cycle may result from interference between centennial-band solar cycles.
Proxy evidence for Sun-climate relations is hardly present for Africa, South America and the marine realm; probably more due
to a lack of information than a lack of response to solar forcing. At low latitudes, equatorward movement of the ITCZ (upward
component of the Hadley cell) occurs upon a decrease in solar activity, explaining humidity changes for (1) Mesoamerica and
adjacent North and South American regions and (2) East Africa and the Indian and Chinese Monsoon systems. At middle latitudes
equatorward movement of the zonal circulation during solar minima probably (co-)induces wet and cool episodes in Western Europe,
and Terra del Fuego as well as humidity changes in Southern Africa, Australia, New Zealand and the Mediterranean. The polar
regions seem to expand during solar minima which, at least for the northern hemisphere is evident in southward extension of
the Atlantic ice cover. The forcing-induced migration of climate regimes implies that solar forcing induces a non linear response
at a given location. This complicates the assessment of Sun-climate relations and calls for nonlinear analysis of multiple
long and high resolution records at regional scale. Unfortunately nonlinear Sun-climate analysis is still a largely barren
field, despite the fact that major global climate configurations (e.g. the ENSO and AO) follow nonlinear dynamics.
The strength of solar forcing relative to other forcings (e.g. volcanism, ocean circulation patterns, tides, and geomagnetism)
is another source of dynamic responses. Notably the climatic effects of tides and geomagnetism are hitherto largely enigmatic.
Few but well-dated studies suggest almost instantaneous, climatic deteriorations in response to rapid decreases in solar activity.
Such early responses put severe limits to the solar forcing mechanisms and the extent of this phenomenon should be a key issue
for future Sun-climate studies. 相似文献
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本文介绍了一个大型钢铁企业原燃料系统的大型MIS。该系统是4个LAN的互联系统,并采用三级客户机/服务器计算模式。该系统初步具备了Intranet规模。 相似文献
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Web信息发布技术的应用 总被引:1,自引:0,他引:1
阐述 W eb 系统的组成及 W eb 系统组织和发布信息的实现过程,给出了将数据库中的数据发布到 W eb 页面的实现方法。 相似文献
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夏冬生 《郑州航空工业管理学院学报(管理科学版)》2001,19(3):65-70
论述了B/S模式下ASP编程中数据传输问题的重要性,分析了基本数据传输的工作原理及ASP接口在编程中的作用,结合本人参与的“比一比”网站(www.cwm168.com)建设实例,说明对数据传输问题的研究有助于更好地发挥ASP技术在Web应用中的作用。 相似文献