251 research outputs found

    Design and Implementation of Time Synchronization Software Between Small Servers

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    目前,大多数计算机之间的时间同步都是通过传统的网络通讯的方式进行的,但在一些物理隔离的计算机或网络之间以及无网络的少数几台近距离的计算机之间等情况,进行时间同步就有点困难。因此针对这一问题,可以通过利用串口通讯的方式来解决这一问题,并利用CPU时间戳与WindowsAPI函数相结合的方法获取精度为1μs的系统时间及CPU的频率来提高时间同步的精度。利用回归自比较法进行了测试,测试结果表明同步精度较高,运行稳定。 本文在深入研究NTP协议的工作原理和工作模式的基础上,尝试着设计开发了一种简单的串口通信中基于NTP协议的服务器和客户端软件,实现了小型服务器间的时间同步。 本文研究内容主要包括:...At present, most of the time synchronization between computers are carried out through the network communication of traditional way, but between the physical isolation of the computer or network and the network without a few machines close to the computer, the time synchronization is a bit more difficult. Therefore, to solve this problem, can solve this problem by using serial communication mode, ...学位:工程硕士院系专业:软件学院_工程硕士(软件工程)学号:X201123039

    The screening of miRNAs involved in WSSV infection and the role of Drosha in shrimp against WSSV

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    对虾白斑综合症病毒(WhiteSpotSyndromicVirus,WSSV),是一种严重危害对虾养殖业的主要病原,目前还未找到有效的防治办法。microRNA(miRNA)是真核生物中一类长度约21个碱基并具有调控基因表达作用的非编码小RNA。研究表明miRNA在发育、免疫等过程中发挥重要作用,但与病毒感染相关的miRNA研究目前很少。因此,本论文筛选和分析对虾中与WSSV感染相关的miRNA,揭示与病毒感染相关的miRNA,同时为对虾病害防治提供依据。 本论文对日本对虾中与WSSV感染有关的miRNA进行了探索。采用WSSV感染对虾,在病毒感染后不同时间(0h,6h,24h和48h),以...White spot syndrome virus is a major pathogen of shrimp, which makes serious economic loss in shrimp aquaculture. However, no effective strategy is available to control the virus at present. microRNAs are a class of non-coding RNAs about 21 nucleotides in length in eukaryotes,which function in the regulates of gene expression. Studies have revealed that miRNAs play key roles in development and imm...学位:理学硕士院系专业:生命科学学院生物学系_生物化学与分子生物学学号:2162007115200

    Discovery of RXRα modulators from Drugbank database and synthetic methodology development of Bisindolylmethanes

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    核受体RXRα作为配体依赖性转录调节因子,参与调控细胞生长、分化等重要生理过程,目前,寻找核受体RXRα的新型配体已成为靶点药物开发的一个重要研究方向。 计算机虚拟筛选方法,可以缩短药物研发的周期,提高先导化合物的发现效率,现已成为药物研发的重要手段。本课题对Drugbank(2.0)老药库进行虚拟筛选,一方面是因为已有舒林酸这个老药新用的成功先例,另一方面是因为老药有着开发周期短、安全性高、成本低等优点。 本课题以核受体RXRα为靶点蛋白,首先,通过计算机虚拟筛选的方法从Drugbank(2.0)老药库中得到了排名靠前的24个化合物,并且购买了其中15个老药并对其进行生物活性评价,通过报...The Retinoid X receptor alpha(RXRα), as a ligand-dependent transcriptional, plays a very important role in many physiological processes, such as regulation of cell growth and differentiation. Virtual screening can improve the efficiency of lead compound discovery and has become one of useful means for drug development. This project use Drugbank(2.0) because of old drugs’ Low cost and Proven safet...学位:医学硕士院系专业:药学院_药物化学学号:3232014115341

    Response characteristic of CYP7A1 and abGSTsigma of Variously Colored Abalone( Haliotis diversicolor Reeve,1846) with bacterial chanllenge and BaP exposure

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    杂色鲍(Haliotisdiversicolor)属软体动物门,腹足纲,前鳃亚纲,原始腹足目,鲍科,是我国南方鲍种,因其生长迅速,经济价值高,在南海海域得到广泛养殖。但长期以来遭受疾病困扰,致使鲍鱼养殖业经常遭受重大损失,而迄今尚无有效的免疫防治措施。为探索鲍的免疫相关机制,本实验室前期利用SSH技术,构建了细菌攻毒杂色鲍血淋巴细胞SSHcDNA文库,发现细菌感染下杂色鲍血淋巴细胞中细胞色素P450(CYP7A1)与谷胱甘肽硫转移酶(abGSTsigma)基因上调表达,推测在鲍体内CYP7A1与abGSTsigma不仅参与异源物质的代谢过程,也可能参与机体的免疫应答过程。本研究拟在此基础上,对...ABSTRACT Abalones, belonging to one of the largest marine gastropod mollusks, are economically important seafood in aquaculture worldwide. In order to study the immunological mechanisms of the abalone, a forward subtractive suppression hybridization (SSH) library from haemocytes of H. diversicolor challenged with bacteria was constructed. P450 (CYP7A1) and GST(abGSTsigma) were selected. Cytochro...学位:工学硕士院系专业:海洋与环境学院环境科学与工程系_环境科学学号:2262006115236

    Analysis of Remaining Salt Policy in the Ming dynasty

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    在近代工商业兴起之前,食盐在国家的经济生活中占有十分重要的地位,因此对于历代盐业研究的重要性不言而喻。本文即是在对有关余盐的史料搜集整理的基础上,以两淮作为一个特定的考察对象,试图对明朝两淮余盐政策的嬗变作一个较为全面的研究,希望可以起到抛砖引玉的作用,引起大家对这一问题的关注。 本文首先介绍了明朝两淮盐区的基本情况,包括两淮盐区在全国所有盐区中所占的重要地位、盐政机构的设置、灶户的情况。此外,对以开中法为主的盐政运行运行状况也作了简单介绍。在对两淮盐区及盐政运行状况有所了解的基础上,开始进入对余盐政策的探究。文章的核心部分即是对整个明朝余盐政策嬗变过程进行梳理,根据相关史料的记载,经过整理...Before the rising of Modern Industry and Commerce, salt played an important role in the economy; in this circumstance, the importance of research on the salt industry in past dynasties goes without saying. Base on collecting and coordinating historic data about remaining salt, this text objects on salt field in Huaihe River, tries to have a comprehensive research on the evolution of Remaining Salt...学位:历史学硕士院系专业:人文学院历史学系_中国古代史学号:1032006115012

    Research on Basic Theories of Typed First-order Logic

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    Prolog是目前最典型和最具代表性的逻辑程序设计语言,但是它在实际的研究和使用中暴露出了诸多不足,Gödel语言的提出很好的解决Prolog的问题。 Gödel语言是继Prolog语言之后出现的新型说明性通用逻辑程序设计语言。它摒弃了Prolog语言中的非逻辑成分,引入了多态多类的类型系统,增加了延迟计算等新的语言成分,具有灵活的计算规则和剪枝操作。这些特点使得它成为一种功能强大的、高效的说明性逻辑程序设计语言。然而,由于缺乏严格的理论基础,包括语法和语义等相关基础理论的支撑,到目前为止,实用的Gödel语言的编译系统始终没有能够推出。为此,首先需要发展G...Prolog is the most typical and representative logic programming language, but many inadequacies are exposed in the actual research and use, Gödel language can solve the problems of Prolog well. Gödel is a new declarative general logic programming language after the Prolog language. It rejects the non-logical components in Prolog language, introduces a polymorphic and polytypic type ...学位:工学硕士院系专业:信息科学与技术学院计算机科学系_计算机软件与理论学号:2302007115130

    The analysis of Citizen’s Reporter

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    “公民记者”诞生于上世纪末的美国。近年来,随着Web2.0技术的不断成熟和便携式电子产品的迅速普及,公民记者迅速发展。公民记者的诞生,颠覆了传统的大众传播方式。普通公民不再只是传统意义上的受众,通过Web2.0平台,普通公民有了空前的话语权。在新媒体时代,公民通过博客、论坛、微博等发布消息,对社会舆论的发展起着推波助澜的作用。 在世界范围内,特别是一些发达国家,公民记者已经打破了传统的传播生态,并在社会政治生活中发挥了积极的作用。但在我国,由于特殊的国情,公民记者的诞生稍显滞后。面对姗姗来迟的公民记者,如何有效的发挥公民记者在社会主义建设中的作用已是当务之急。本文从公民记者的诞生及其相关概念...The first Citizen’s reporter was born in the U.S.A. in the end of the last century. In recent years, Citizen’s reporter developed rapidly as Web2.0 technology being more mature and portable electronics becoming popular. The birth of the citizen reporter has completely overturned the traditional way of the mass media. Ordinary citizens were no longer just a conventional sense of audiences, ordinary...学位:文学硕士院系专业:新闻传播学院新闻学系_新闻学学号:1052008115314

    高等教育目的:克拉克·克尔的观点

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    本文梳理了克拉克.克尔多层次多侧面的高等教育目的观的基本内容,主要包括高等教育目的的差异与变革、高等教育目的观谱系及克尔的立场,以及变化中的美国高等教育目的。在此基础上,对克尔的高等教育目的观进行评论和思考

    Understanding Philip·G. Altbach's Standpoint——After Comparing higher Education: Knowledge, the University and Development

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    作为美国体制内知识分子,阿尔特巴赫既具有美国人普遍存在的“西方中心主义”的傲慢,同时严格恪守体制内知识分子的学术责任;作为一个心怀天下的学者,他在力求使自己的研究客观公正的同时关注弱势、不满霸权、祈望世界知识网络中不平等的祛除。As an intellectual within American system, Altbach is arrogantly Western-centered and scrupulously abides by the academic responsibilities of intellectuals within national academic system. As a far-sighted scholar, he is impersonal and impartial in his study and attention to the disadvantaged, critical of the supremacy and look forward to elimination of the inequality in the academic circle of the world

    Theoretical Proof of Typed First-order Logic

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    类型一阶逻辑在传统的一阶逻辑上,引入了类型,它是多态多类逻辑程序设计语言的理论基础,对编译系统设计与实现的进一步发展具有重要意义。论文在类型一阶逻辑的理论层面进行了探讨,引入了基本简单导出的可靠性定理和等值符号的可替换性定理,并予以证明。通过这两个定理,可以简化类型一阶逻辑理论证明中的工作量,使得将来的理论研究更加方便。Type is introduced into the typed first-order logic,which is based on the traditional first-order logic and the theoretical foundation of polymorphic and polytypic logic programming language.Typed first-order is significant to the further development of the design and implementation of compilation system.This paper is a research at the theoretical level and it introduces reliability theorem of the basic and simple derivation and the exchangeability theorem of the equivalent symbols,and the two theorems are proved in this paper.With the two theorems,the workload of the first-order logic proof can be simplified and the future theoretical research will be easier
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