共查询到20条相似文献，搜索用时 93 毫秒
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1. Cohesion and Coherence According to Halliday and Hasan (1976: 4), cohesion is relations of meaning that exist within the text and that define it as a text. Cohe- sion occurs where the interpretation of some element in the discourse is dependent on that of another. Grammar and lexis are two means to realize the goal of cohesion. In other words, there are grammatical co- hesion and lexical cohesion. Coherence refers to the relationships, which link the meanings of utterances in a discourse … 相似文献
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The paper argues that the theory that opens out the nature of subject indexing process is required, if the process consists of a tremor of steps and elements and it is a range of interpretations, too. The paper points out that Peirce' s semiotics is the theory by which we may study and understand the lmture of interpretation in subject indexing pro-cess. In recent years, there is a great interest in semiofcs in library and information science field. The paper discusses some basic issues of semiotics and its use in information science. 相似文献
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《国家科学评论(英文版)》2014,(2)
PIWI-interacting RNAs(piRNAs) are a complex class of small non-coding RNAs that are mostly 24–32nucleotides in length and composed of at least hundreds of thousands of species that speciically interact with the PIWI protein subfamily of the ARGONAUTE family. Recent studies revealed that PIWI proteins interact with a number of proteins, especially the TUDOR-domain-containing proteins, to regulate piRNA biogenesis and regulatory function. Current research also provides evidence that PIWI proteins and pi RNAs are not only crucial for transposon silencing in the germline, but also mediate novel mechanisms of epigenetic programming, DNA rearrangements, m RNA turnover, and translational control both in the germline and in the soma. hese new discoveries begin to reveal an exciting new dimension of gene regulation in the cell. 相似文献
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论网络载体环境下科学信息交流过程的基本特征 总被引：8，自引：0，他引：8
The paper indicates that the scientific information communication process in the network environment has lots of new characters compared with the traditional paper-based communication process. In this paper, the author dissertates 4 of these characters, that is, shortening of the communication process; quickening of communication speed and increasing of information quantity; virtualization of information organization and weakening of the door-keeper. 相似文献
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《中国科学院院刊(英文版)》2015,(4)
<正>The area and elevation of the Tibetan Plateau over time has directly affected Asia's topography,the characteristics of the Asian monsoon,and modified global climate—but in ways that are poorly understood.Charting the uplift history is crucial for understanding the mechanisms that link elevation and climate irrespective of time and place.While some palaeoelevation data are available for southern and central Tibet,clues to the uplift history of northern Tibet remain sparse and largely circumstantial.Lately,researchers from the CAS Institute of Botany 相似文献
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《中国科学院院刊(英文版)》2004,(2)
On the occasion of the 30th anniversary of the establishment of cooperation between the Chinese Academy of Sciences and the Max Planck Society for the Advancement of Science, 1 hope that the scientific and technological cooperation between the two organizations can be continu- 相似文献
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《中国科学院院刊(英文版)》2003,17(1):9-9
CAS researchers announced inChinas Modernization Re-port 2003 that the gap be-tween the Chinas modernizationlevel and that achieved by developedcountries is narrowing steadily.The report, which was recentlycompleted by the CAS Moderniza-tion Research Center (MRC), ana-lyzes the theories and practice of themodernization research during thelast 50 years of the 20th century. Onthe basis of analyzing a great amountof data, researchers suggest that theworldwide course of modernizationdrive fr… 相似文献
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This paper discusses the INAA results of REE in clays atand near some Permian/Triassic boundaries of South China.It showsthat the REE patterns of boundary clays differ from those of non-boundary clays.One difference is that the boundary clays are moreenriched in LREE,with steeper slope of REE and a smaller Eu nega-tive anomaly than the non-boundary clays.Another difference is that theboundary clays show a small Ce negative anomaly,but no Ce anomalyoccurs in the non-boundary clays.From these REE patterns and some other experimental facts,it isproposed that the P/T boundary clay may be a mixed product consistingof the acidic-intermediate ash and the upper crust substance representingsputtering component,and the calculated fraction of the former andlatter is 7/3. 相似文献
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MARC未来及质量控制 总被引：1，自引：0，他引：1
本文首先介绍了MARC格式的背景和基本功能,指出现行的著录和MARC格式首先要遵循"巴黎原则",应该着眼于著录和著录格式的未来发展,搭建成一个更为可靠、面向用户的平台。最后探讨了未来MARC格式质量控制指标和未来著录实践和书目记录可能采用的大致轮廓。 相似文献
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传统图书馆在文献资源建设过程中,一般都采用自己专有的MARC格式,而这种格式一般都只有图书馆专有系统才可以识读。通过MARC与XML的转换,使得实现面向WWW的MARC信息提供成为可能。本文探讨了基于XML的MARC转换设计及其原理,并给出了一个XML描述MARC记录的实例,结合实例分析了MARC元数据的XML描述优势。 相似文献
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首先分析了MARC数据的结构和一些特殊字符在此结构中的功能。其次确定什么形式的数据用户易于理解。对MARC数据的转换和提取方法进行分析,提出MARC数据的转换提取方案和流程,给出JSP下的代码实现。最后就代码实现中遇到的特殊字符的ASCII码和中文字符占位问题提出了解决办法。 相似文献
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图书馆网络信息资源的描述与组织方式发展研究 总被引：4，自引：0，他引：4
本文探讨了MARC依然存在的原因，对网络信息资源的描述与组织两种方式即后控与先控为代表的元数据的产生、内容、功能进行了介绍，并给出了一定的综合讨论。 相似文献
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论述MARC元数据在网络信息资源编目中应用的可行性及优点,并探讨MARC元数据在网络信息资源编目中的应用及发展方向. 相似文献
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MODS与MARC、DC之比较研究 总被引：1，自引：1，他引：1
MODS是美国国会图书馆正在研制的一种新的文献编目数据，它是继MARC之后开发的第二种以MARC为基础的文献编目元数据。分析MODS的特点，并将MODS与MARC、DC分别进行比较。 相似文献
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MARC在信息资源管理中优缺点的研究 总被引：3，自引：0，他引：3
本文从信息资源管理的角度对MARC的优缺点进行了详细分析，从而得出了在图书馆界短期内MARC不可被替代并有着广阔发展前景的结论。 相似文献
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针对目前MARC元数据网络发布系统的弊端，提出了基于XML的MARC元数据网络发布结构体系，并对其中应用的主要技术及实现方法进行了较深入的探讨。 相似文献