全文获取类型
收费全文 | 38644篇 |
免费 | 514篇 |
国内免费 | 821篇 |
专业分类
教育 | 26755篇 |
科学研究 | 5161篇 |
各国文化 | 27篇 |
体育 | 2615篇 |
综合类 | 1958篇 |
文化理论 | 425篇 |
信息传播 | 3038篇 |
出版年
2024年 | 12篇 |
2023年 | 51篇 |
2022年 | 302篇 |
2021年 | 633篇 |
2020年 | 485篇 |
2019年 | 354篇 |
2018年 | 2387篇 |
2017年 | 2371篇 |
2016年 | 1865篇 |
2015年 | 1040篇 |
2014年 | 1619篇 |
2013年 | 1912篇 |
2012年 | 2284篇 |
2011年 | 3042篇 |
2010年 | 3063篇 |
2009年 | 2544篇 |
2008年 | 2733篇 |
2007年 | 3247篇 |
2006年 | 2083篇 |
2005年 | 2054篇 |
2004年 | 1600篇 |
2003年 | 1297篇 |
2002年 | 1057篇 |
2001年 | 793篇 |
2000年 | 475篇 |
1999年 | 237篇 |
1998年 | 108篇 |
1997年 | 87篇 |
1996年 | 55篇 |
1995年 | 41篇 |
1994年 | 41篇 |
1993年 | 12篇 |
1992年 | 22篇 |
1991年 | 20篇 |
1990年 | 10篇 |
1989年 | 7篇 |
1988年 | 4篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1965年 | 2篇 |
1964年 | 1篇 |
1963年 | 1篇 |
1957年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
常樱 《中国国家博物馆馆刊》2020,(3):126-135
"摩羯"源于古印度,佛经翻译引入"摩羯鱼王"的概念不晚于三国时期。国内发现最早的摩羯纹来自北魏舶来之大夏银杯,最早的本土摩羯图像应是正定隆兴寺藏东魏至北齐佛造像背光线刻摩羯戏水。唐代佛教流行的"六拏具"与"天龙八部"图式中含摩羯,同期属于世俗装饰系统的陶瓷、金银器摩羯图案则经本土化发展为鲤鱼身形,其飞翅龙角的特征对辽人影响深切。北宋以后,占星算命成为显学,"摩羯命"导致人生困顿的说法流行,摩羯纹就此衰落。与此同时,受科举考试影响,民间孕育出了新的"鱼化龙纹",在磁州窑、耀州窑、景德镇窑的民用陶瓷产品中均有体现。 相似文献
992.
993.
994.
2007年4月24日新华社授权发布了《中华人民共和国政府信息公开条例》(以下简称《条例》),首次对我国政府信息公开的原则和范围、方式和程序、监督和保障等内容作出了全面、系统的规定,《条例》的颁布为政务公开提供了法律依据,也为公众知情权提供了法律保障. 相似文献
995.
Diego Reforgiato Recupero 《Information Retrieval》2007,10(6):563-579
Text document clustering provides an effective and intuitive navigation mechanism to organize a large amount of retrieval
results by grouping documents in a small number of meaningful classes. Many well-known methods of text clustering make use
of a long list of words as vector space which is often unsatisfactory for a couple of reasons: first, it keeps the dimensionality
of the data very high, and second, it ignores important relationships between terms like synonyms or antonyms. Our unsupervised
method solves both problems by using ANNIE and WordNet lexical categories and WordNet ontology in order to create a well structured
document vector space whose low dimensionality allows common clustering algorithms to perform well. For the clustering step
we have chosen the bisecting k-means and the Multipole tree, a modified version of the Antipole tree data structure for, respectively, their accuracy and
speed.
相似文献
Diego Reforgiato RecuperoEmail: |
996.
Intelligent use of the many diverse forms of data available on the Internet requires new tools for managing and manipulating
heterogeneous forms of information. This paper uses WHIRL, an extension of relational databases that can manipulate textual
data using statistical similarity measures developed by the information retrieval community. We show that although WHIRL is
designed for more general similarity-based reasoning tasks, it is competitive with mature systems designed explicitly for
inductive classification. In particular, WHIRL is well suited for combining different sources of knowledge in the classification
process. We show on a diverse set of tasks that the use of appropriate sets of unlabeled background knowledge often decreases
error rates, particularly if the number of examples or the size of the strings in the training set is small. This is especially
useful when labeling text is a labor-intensive job and when there is a large amount of information available about a particular
problem on the World Wide Web.
相似文献
Haym HirshEmail: |
997.
Result merging methods in distributed information retrieval with overlapping databases 总被引:5,自引:0,他引:5
In distributed information retrieval systems, document overlaps occur frequently among different component databases. This
paper presents an experimental investigation and evaluation of a group of result merging methods including the shadow document
method and the multi-evidence method in the environment of overlapping databases. We assume, with the exception of resultant
document lists (either with rankings or scores), no extra information about retrieval servers and text databases is available,
which is the usual case for many applications on the Internet and the Web.
The experimental results show that the shadow document method and the multi-evidence method are the two best methods when
overlap is high, while Round-robin is the best for low overlap. The experiments also show that [0,1] linear normalization
is a better option than linear regression normalization for result merging in a heterogeneous environment.
相似文献
Sally McCleanEmail: |
998.
Brian Edward Hubner 《Archival Science》2007,7(3):195-206
Census information of some form has been collected in Canada since the 1611 census of New France. Aboriginal people, identified
or not, have been included in these enumerations. The collection of this information has had a profound impact on Aboriginal
people and has been an element that has shaped their relationship with the dominant society. In response, Canadian Aboriginal
people have often resisted and refused to co-operate with census takers and their masters. This article is an examination
of this phenomenon focused on the censuses conducted in the post-Confederation period to the present. A census is made to
collect information on populations and individuals that can then be used to configure and shape social and political relations
between those being enumerated and the creators of the census. However, the human objects of the census are not just passive
integers and they have resisted its creation in a number of ways, including being “missing” when the census is taken, refusing
to answer the questions posed by enumerators or even driving them off Aboriginal territory. A census identifies elements of
the social order and attempts to set them in their “proper” place and those who do not wish to be part of that order may refuse
to take part. Archivists and historians must understand that the knowledge gained in a census is bound with the conditions
of own creation. This has been noted by contemporary Aboriginal researchers who often state that the archival record of their
people often distorts history and reflects the ideas and superficial observations of their Euro-Canadian creators. Changes
to the Census of Canada since 1981, have increased the participation rate and therefore changed the nature of the record.
Brian Edward Hubner is currently Acquisition and Access Archivist at the University of Manitoba Archives & Special Collections. He was previously employed at the Archives of Manitoba, in Government Records; Queen’s University Archives, Kingston; and at the National Archives of Canada, Ottawa. He has a Master of Arts (History, in Archival Studies) from the University of Manitoba, and a Master of Arts (History), from the University of Saskatchewan. The 2nd edition of Brian’s co-authored book on the history of the Cypress Hills of Saskatchewan and Alberta is being published in 2007. He has published articles and delivered conference papers on Canadian Aboriginal peoples including “Horse Stealing and the Borderline: The N.W.M.P. and the Control of Indian Movement, 1874-1900.” His current research interest focuses on relationship between Canada’s Aboriginal Peoples and Canadian archives. Brian is married and has two children. 相似文献
Brian Edward HubnerEmail: |
Brian Edward Hubner is currently Acquisition and Access Archivist at the University of Manitoba Archives & Special Collections. He was previously employed at the Archives of Manitoba, in Government Records; Queen’s University Archives, Kingston; and at the National Archives of Canada, Ottawa. He has a Master of Arts (History, in Archival Studies) from the University of Manitoba, and a Master of Arts (History), from the University of Saskatchewan. The 2nd edition of Brian’s co-authored book on the history of the Cypress Hills of Saskatchewan and Alberta is being published in 2007. He has published articles and delivered conference papers on Canadian Aboriginal peoples including “Horse Stealing and the Borderline: The N.W.M.P. and the Control of Indian Movement, 1874-1900.” His current research interest focuses on relationship between Canada’s Aboriginal Peoples and Canadian archives. Brian is married and has two children. 相似文献
999.
Beatrice S. Bartlett 《Archival Science》2007,7(4):369-390
This article describes the first half century of the Communist government’s supervision and management of the central-government
archives of the last two dynasties. Immediately with the Communist ascent to power in 1949, the new government took great
interest in assembling and protecting the country’s archival documents, readying the Ming-Qing archives for access to scholars,
and preparing for publication of selected materials. By the 1980s Beijing’s Number One Historical Archives, in charge of the
largest holding of Ming-Qing documents, had become the first Chinese authority to complete a full sorting and preliminary
catalogues for such a collection. Moreover, to facilitate searches, an attempt has recently begun to create a subject-heading
system for these and other holdings in the country. In the first half century’s final decades, foreign researchers were admitted
for the first time and tours and international exchanges began to take place.
相似文献
Beatrice S. BartlettEmail: |
1000.
Previous papers on grey literature by the authors have described (1) the need for formal metadata to allow machine understanding
and therefore scalable operations; (2) the enhancement of repositories of grey (and other) e-publications by linking with
CRIS (Current Research Information Systems); (3) the use of the research process to collect metadata incrementally reducing
the threshold barrier for end-users and improving quality in an ambient GRIDs environment. This paper takes the development
one step further and proposes “intelligent” grey objects. The hypothesis is in 2 parts: (1) that the use of passive catalogs
of metadata does not scale (a) in a highly distributed environment with millions of nodes and (b) with vastly increased volumes
of R&D output grey publications with associated metadata; (2) that a new paradigm is required that (a) integrates grey with
white literature and other R&D outputs such as software, data, products and patents (b) in a self-managing, self-optimizing
way and that this paradigm manages automatically curation, provenance digital rights, trust, security and privacy. Concerning
(1) existing repositories provide catalogs; harvesting takes increasing time ensuring non-currency. The end-user expends much
manual effort/intelligence to utilize the results. The elapsed time of (1) the network (2) the centralized (or centrally controlled
distributed) catalog server searches (3) end-user intervention becomes unacceptable. Concerning (2) there is no paradigm currently
known to the authors that satisfies the requirement. Our proposal is outlined below. Hyperactive combines both hyperlinking
and active properties of a (grey) object. Hyperlinking implies multimedia components linked to form the object and also external
links to other resources. The term active implies that objects do not lie passively in a repository to be retrieved by end-users.
They “get a life” and the object moves through the network knowing where it is going. A hyperactive grey object is wrapped
by its (incrementally recorded) formal metadata and an associated (software) agent. It moves through process steps such as
initial concept, authoring, reviewing and depositing in a repository. The workflow is based on the rules and information in
the corporate data repository with which the agent interacts. Once the object is deposited, the agent associated with it actively
pushes the object to the end-users (or systems) whose metadata indicate interest or an obligation in a workflowed process.
The agents check the object and user (or system) metadata for rights, privacy, security parameters, and for any charges and
assure compatibility. Alternatively the object can be found passively by end-user or system agents. The object can also associate
itself with other objects forming relationships utilising metadata or content. Declared relationships include references and
citations; workflowed relationships include versions and also links to corporate information and research datasets and software;
inferenced relationships are discovered relationships such as between documents by different authors developed from an earlier
idea of a third author. Components of this paradigm have been implemented to some extent. The challenge is implementing—respecting
part two of the hypothesis—the integration architecture. This surely is harnessing the power of grey.
相似文献
Anne AssersonEmail: |