170 research outputs found

    Vertical structure of 234Th in the northern basin of the South China Sea: seasonal variation and its biogeochemical implication

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    234Th已被广泛地应用于海洋颗粒动力学的研究。利用234Th/238U不平衡法可以估算234Th输出通量,进而评估颗粒有机碳(POC)等生源要素的输出通量。本论文采用小体积二氧化锰共沉淀法测定总234Th的活度,样品采自2007年9月、2009年1月秋冬两个航次,此外,结合2004年7月和2005年5月的数据(来自陈蔚芳(2008)),论文在分析了南海北部海盆东南亚时间序列站(theSouthEastAsiaTime-seriesStation,SEATS)500m以浅234Th的垂直分布特征及其季节变化的基础上,揭示了冬季南海北部海盆200-500m水深之间,存在来自陆架的颗粒物侧向运移,...Thorium-234 is a particle-reactive isotope, serving widely as an important tracer to explore the particle dynamics in the ocean. Based on the 234Th/238U disequilibria, 234Th export fluxes can be deduced and subsequently converted to export fluxes of particulate organic carbon (POC) or other biogenic elements. In this study, depth profiles (upper 500 m) of particulate and total 234Th were collected...学位:理学硕士院系专业:海洋与环境学院环境科学与工程系_环境科学学号:2262007115237

    Effect of leptin on apoptosis and molecular mechanism of different tumor cells

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    瘦素是分子量大小为16kD的蛋白分子,作为一种信号分子其主要功能是调节人体脂肪含量,同时它也具有调节生长发育,调节炎症反应、免疫功能、维持正常的血脂代谢等功能。近年来越来越多的研究资料表明,人体内的血清瘦素水平与乳腺癌、宫颈癌、结肠癌、前列腺癌、脑瘤、脂肪瘤等的发生都有着一定的关系,血清瘦素水平是癌症患者的一个重要的监测指标。但瘦素对肿瘤生长的影响及其作用机制仍未阐明,瘦素对肿瘤细胞株的直接作用研究报道不多。为了探讨瘦素对肿瘤细胞株生长增殖的影响及其作用的分子机制,本实验根据NCBI中公布的人瘦素cDNA序列,设计并合成了6个89bp左右的DNA小片断,经重叠PCR扩增获得464bp重组的人瘦...ptide hormone, is a proposed fat mass regulator for the body. It is involved in regulating food intake, metabolism, energy expenditure, and neuroendocrine function.More and more reaserch indicated that leptin has certain relationship with galastirc cancer,gastric cancer,liver cancer,intestine cancer and so on.The change of leptin level is the important sign of cancer occurring. But the mechanism b...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:20042613

    The Study on Public Participation in the Supply of Public Goods in China’s Rural Area

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    农村公共物品供需矛盾是当前农村的一个突出问题,主要表现在供给数量不足、供需结构失衡和供给效率低下等方面。这一问题极大地影响了农业的生产发展、农民的减负增收和农村的和谐稳定,也引起了全社会的广泛关注和重视。近年来,国家不但在政策上向农村倾斜,而且在财政上也加大了资金投入力度,从而在一定程度上缓解了供需紧张的局面。但当前形势依然严峻,供需矛盾仍然十分尖锐,究其根源在于农村公共物品供给中公共参与的缺失。本文以农村公共物品供需矛盾为研究对象,以公共参与为理论切入点,试图运用公共参与来分析农村公共物品供给中存在的问题,通过扩大公共参与农村公共物品供给,实现供给和需求的平衡,促进该问题的解决。 本文主体...The contradictions between the supply and demand of public goods in China’s rural area has become a critical issue that needs to be addressed, especially the shortage of quantity, the unreasonable structure and the inefficient supply. This issue has great impact on the development of agricultural production, the increase of farmers’ incomes and the stability of the countryside. These problems have...学位:管理学硕士院系专业:公共事务学院公共管理系_行政管理学号:2005130065

    A study of ZhangGgang and his poetry

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    张纲一生仕历徽宗、钦宗、高宗三朝,官至参知政事,是宋代名臣。他历经“靖康之耻”和“绍兴和议”,是北宋末、南宋初政治风云变幻的见证者。他著述颇丰,现存《华阳集》四十卷。其诗词创作在当时颇受好评,然而至今其生平事迹未见有专文论述,故而稽考他的生平并对他的诗词创作进行研究显得很有意义。本文将据张氏本集及相关文献,详考其家世、生平事迹、厘清其著述的编刻传播。并在其基础上,对他的诗词创作进行研究,考察其诗词创作的背景、主题变迁、风格特征,并对他诗词创作的得失进行客观公正的评价。文章分为引言、上编、下编、结语四部分: 引言部分,主要介绍文章的选题缘起、研究现状、研究目标等,并对文章内容进行简单概括。 ...Zhang Gang is a famous respected political official who lived through the Southern Song Dynasty of Hui Zong Qing Zong and Gao Zong emperor. He has many writings, the existing HuaYang Collection is his Forty’s volumes works. His poetry has his own characteristics that showing reversion to Tang poetry is acclaimed at that time he alive. Zhang Gang experienced "Jingkang Humiliation" and "Shaoxing neg...学位:文学硕士院系专业:人文学院_中国古代文学学号:1022013115241

    Design and Implementation of Small and Medium Library Management System

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    随着科学技术的飞速发展,计算机科学技术逐步走向成熟,并在人类的各个领域发挥着越来越重要的作用。作为计算机应用的一部分,使用图书管理系统对图书资源信息进行管理,不仅使图书检索速度大大加强,图书存储量加大,而且有着比手工管理所无法比拟的优点,比如可靠性强、成本低廉、保密性好等等。目前市场上的比较有名的图书管理系统都具有数据处理量大、图书管理功能较完备、采用了大型数据库开发平台等共同特点。但是中小型图书馆一般都存在经费紧张、缺乏计算机专业人员等问题,对于这种大型系统的购买、使用和维护均有相当大的困难。因此,开发中小型图书馆图书管理系统对于中小型图书馆来说是切实可行的解决办法。 本文以某高校学院图...With the rapid development of science and technology, computer science and technology gradually become mature and play a more and more important role in every field. As a part of computer applications, using library management system to manage resource information of the books, not only makes the retrieval speed greatly enhanced, book storage quantity enlarged, but also has incomparable advantages...学位:工程硕士院系专业:软件学院_工程硕士(软件工程)学号:X201023049

    A Study of Deliberate Misinterpretation in English Daily Conversations from the Pragmatic Perspective

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    在人类言语交际中,当听话人没有正确理解说话人意欲传达的意义时,误解就会发生。但在某些言语交际中,语言使用者为了达到某种交际目的,刻意选择与对方的话语意图相脱离的理解,以达到某种交际效果。这种语言现象被定义为刻意曲解。 本文以四部美国电视剧的对话中的例子为材料,分析英语日常对话中刻意曲解这一语言现象的触发因素和交际功能。刻意曲解的触发因素主要分两类,即第一说话人话语中语境意义的不确定性和第一说话人话语中语力的不确定性,具体的因素有:同音异形词、同形异义词、指示语、最简信息、结构歧义和会话含义。这些触发因素为第二说话人曲解第一说话人的话语提供了潜在的可选项。刻意曲解是第二说话人在某种交际需求的驱...In human verbal communication, misunderstanding occurs when the hearer’s understanding of the speaker’s utterance is not identical with the speaker’s intended meaning. However, in some cases, the hearer may deliberately choose the interpretation diverging from the speaker’s intended meaning in order to achieve certain communicative effects. This kind of linguistic phenomenon is deliberate misinter...学位:文学硕士院系专业:外文学院英语语言文学系_英语语言文学学号:2005130030

    Development of Upconversion Phosphors with Three Primary Colors based on Rare-Earth doped Solid Compounds

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    本论文主要采用固相法制备Er3+/Yb3+离子掺杂的复合氟化物、Tm3+/Yb3+离子掺杂的复合氟化物、以及Er3+/Yb3+离子掺杂的氯氧化物和氟氧化物的上转换荧光粉,系统探讨离子掺杂浓度、荧光粉基质材料以及热处理工艺等对荧光粉性能的影响,并对影响上转换荧光粉性能的发光机理进行初步探讨.采用固相法制备可由980nm激光器上转换用绿色荧光粉NaYF4:Er3+/Yb3+,通过两步法制备高纯度的六方相NaYF4,并改变激活剂Er3+离子浓度和敏化剂Yb3+离子浓度,调节绿光和红光的相对强度比,得到高纯度的绿色荧光粉;比较了NaF和Na2SiF6两种不同原料对荧光粉性能的影响,发现用NaF制备样品...In this thesis, several kinds of phosphors were synthesized via solid-state reaction method, including rare earth ion Er3+/Yb3+ co-doped sodium yttrium fluoride based green emitting upconversion phosphor, Tm3+/Yb3+ co-doped sodium yttrium fluoride based blue emitting upconversion phosphor, Er3+/Yb3+ co-doped YOCl and YOF based red emitting upconversion phosphor. It was systematically discussed for...学位:工学硕士院系专业:化学化工学院材料科学与工程系_材料学学号:2005130195

    Salt-regulated function of OmpW and OmpV in Bacteria

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    研究背景:海洋病原菌不仅对水产养殖造成巨大的经济损失还对人类健康形成一定的威胁。对不同的盐度环境的适应能力是海洋病原性微生物的一种基本机能,同时这也与细菌致病能力及繁殖传播能力紧密相关,而外膜蛋白处于细菌的最外层,直接与外界环境(包括海洋环境和宿主体内环境两面)相接触,对其展开深入研究是分析细菌盐度适应机制的一个重要的方面。OmpW和OmpV是细菌外膜蛋白中的重要蛋白,目前国际上对这两个蛋白还缺乏深入的研究,虽然有些证据表明它们可能是属于孔蛋白或通道蛋白,但是对它们具体的结构、功能仍然很不清楚。研究目的:探讨美人鱼发光杆菌OmpW和OmpV的存在,研究OmpW和OmpV在弧菌和杆菌中的分布,揭...Background: A variety of marine pathogens can cause gastroenteritis, wound infections, and primary septicemia as well as illness among marine organisms. These infectious diseases cause magnitude losing in aquiculture and even a threaten to human being`s health. How to adapt the different Na+ concentrations is a basic mechanism for the pathogen. Gram-negative bacteria characteristically are surroun...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:20032612

    A Study on the System and Mechanism Construction of Social Management with Chinese Characteristics

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    社会管理是一个相当有中国特色的词语。改革开放以来,随着经济体制的转轨和社会的转型,社会流动性大大增加,社会问题与事务与日增多,传统的社会管理理念和方式都难以实现有效的管理,社会问题造成的影响在不断的增大。在这样的情况下迫切需要建立起一种与社会发展阶段相适应社会管理模式,这已经成为广泛的共识,政府、学者、社会人士都在积极呼吁与不断实践。 在构建具有中国特色的社会管理模式时,我们首先要明确的是社会管理是一个涵盖社会生活方方面面的完整体系,是由各个社会管理体制与社会管理机制有机结合组成的。不断完善社会管理体制与机制建设是当前社会管理水平不断提高的必经之路。创新与完善需要建立在对历史的清醒认识和对现...Social management is a word with Chinese characteristics. Since the Chinese reform and opening, especially since the economic reform and social transformation, social mobility is greatly increased. At the same time, social problems and social affairs are also increasing quickly. Traditional social management ideas and methods are difficult to provide effective management; the impact of social prob...学位:管理学硕士院系专业:公共事务学院_行政管理学号:1392010115049

    从张爱玲到李安——浅析电影《色·戒》对同名小说的改编

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    电影《色·戒》是对同名小说的再诠释。它在忠于原著主题的基础上,对原著进行结构、细节等方面的改编,从而对原著的思想内核进行了深化,也使得小说的女性意识与及女性悲剧的历史观在影片中得以升华。电影《色·戒》是一次创造性的改编,它运用了精湛独到的拍摄手段、取景方法、影视叙事模式等为我们展现了一个“重生“的《色·戒》,也给了我们心灵的震撼
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