基于PKI的高校安全教务管理研究

随着Internet技术的快速发展,基于B/S结构的网上教务管理系统为学院教务工作的办公自动化注入了新的活力.但在使用过程中非法监听、非法修改、事后否认等行为逐渐成为威胁系统安全亟待解决的问题.本文就如何将DES及RSA加密算法、公钥基础设施(PKI)及数字签名技术应用于网上教务管理系统以实现安全教务管理进行研究.通过实践证明利用加密、数字签名等技术构建的网上教务管理系统,可以实现安全的网上数据提交、存储、传输及使用,有效保证了信息的保密性,具有一定的使用价值.     

基于B/S结构的教务管理系统中的数字签名

随着Internet/Intranet技术和教育事业的发展,教务管理系统正在由C/S结构的运行模式转为B/S结构的运行模式.在基于B/S模式下的教务管理信息系统中,为了防止非法用户录入或者修改学生的成绩,本文阐述了如何采用数字签名机制来进行用户身份认证,从而保证成绩的真实性和系统的安全性.通过对学生、教师、教学管理员、课程、课件及密钥等的管理以及数字签名在系统中的实现,使系统成为一个高效、完善、安全易用的管理信息系统.     

公钥基础设施PKI及其在网上阅卷系统中的应用

安全是网络活动最重要的保障，本文以PKI技术为基础，简单列举了其基本组成，并介绍了其技术特点。为了更好地做好教务管理，设计出了一个应用PKI技术实现网上阅卷管理系统的实例。     

XML数字签名在高校教务管理系统中的应用

作为高校数字化校园的一部分,教务管理系统正在由功能型向安全高效型转变.文中研究了在教务管理系统中利用XML数字签名取代原本需要手工签名的方法,给出了一个具体的创建证书、签名、验证的实现过程.     

圆锥曲线有序多重签名方案的研究与应用

在研究圆锥曲线密码体制的基础上,设计了一个基于双难题的圆锥曲线有序多重数字签名方案,并将其与XML数字签名技术相结合,实现了高校教务管理系统中对学生成绩的多重数字签名,以保证学生成绩信息的有效性、真实性和完整性,提高学生成绩管理的工作效率,增强教务管理系统的实用性.通过系统的运行验证,以及与椭圆曲线有序多重数字签名方案比较,对学生成绩的有序多重数字签名达到预期效果,系统的安全性和运行效率得到进一步的提高.     

公钥基础设施PKI及其在网上阅卷系统中的应用

安全是网络活动最重要的保障,本文以PKI技术为基础,简单列举了其基本组成,并介绍了其技术特点。为了更好地做好教务管理,设计出了一个应用PKI技术实现网上阅卷管理系统的实例。     

分布式学籍管理系统中的群签名及其实现

结合群签名技术在分布式学籍管理系统中的应用，介绍了数字签名、群签名的原理及特点，详细介绍了分布式学籍管理系统中一种群签名方案的实现过程。该系统具有保密、安全、一致、鉴别的特点，完全实现了手工学籍管理的各道程序，保存群签名，实现了可靠的、无纸化学籍管理。     

XML数字签名技术在函授成绩管理中的应用

文中介绍了XML数字签名技术,在基于校园网的综合教务系统中使用XML数字签名技术确保函授学员的成绩真实、有效,并用JAVA语言实现了数字签名和验证.     

ADO在教务管理系统中的应用

阐述ADO技术在教务管理系统中的应用，并以教务管理系统中的学生基本信息管理为例，分析使用ADO技术访问数据库的方法．     

计算机网络远程教育平台的研究

从计算机网络远程教育的教学活动及特点出发，对计算机网络远程教育平台进行了研究，规划出了计算机网络远程教育的硬件平台和软件平台．软件平台包括：网上教务管理系统、网上教学平台、网络题库管理系统、教学资源库管理系统、智能答疑系统、学习管理系统、作业管理系统、考试与评价系统、网络课件写作系统、基于Web的虚拟实验室．     

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.     

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.     

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.     

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.     

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.     

A computer generator for randomly layered structures

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

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。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.     

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.