首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   3530篇
  免费   38篇
  国内免费   6篇
教育   2192篇
科学研究   499篇
各国文化   17篇
体育   275篇
综合类   8篇
文化理论   44篇
信息传播   539篇
  2022年   20篇
  2021年   22篇
  2020年   44篇
  2019年   57篇
  2018年   112篇
  2017年   155篇
  2016年   137篇
  2015年   89篇
  2014年   107篇
  2013年   533篇
  2012年   120篇
  2011年   143篇
  2010年   117篇
  2009年   86篇
  2008年   78篇
  2007年   114篇
  2006年   61篇
  2005年   81篇
  2004年   66篇
  2003年   60篇
  2002年   53篇
  2001年   87篇
  2000年   70篇
  1999年   61篇
  1998年   54篇
  1997年   43篇
  1996年   51篇
  1995年   25篇
  1994年   34篇
  1993年   20篇
  1992年   45篇
  1991年   44篇
  1990年   30篇
  1989年   39篇
  1988年   34篇
  1987年   31篇
  1986年   36篇
  1985年   39篇
  1984年   38篇
  1983年   22篇
  1982年   33篇
  1981年   24篇
  1980年   16篇
  1979年   35篇
  1978年   30篇
  1977年   21篇
  1976年   16篇
  1974年   21篇
  1972年   25篇
  1971年   19篇
排序方式: 共有3574条查询结果,搜索用时 265 毫秒
941.
An interactive system of expert evaluations of offers made by the Russian and foreign information market of scientific literature issued in both printed and electronic form is described. The system supports the database of experts and the periodically updated database of offers of the information market. An expert evaluation is carried out over the internet from a special division of the LNS RAS site, access to which is available only to authorized users, i.e., experts. Expert selectors make decisions about ordering various editions for funding from the centralized library system by analyzing tables formed based on processed results from expert evaluations with the help of specially created software tools.  相似文献   
942.
Using data from Ulrich’s Periodicals Directory, and the extent of coverage by abstract information resources and indices, the worldwide output of periodicals and proceedings (including those represented in electronic form) is studied. A quantitative characterization of the entire output of worldwide editions, as well as its abstracted portion is given. To provide complete reception of needed subject information and cover a maximum number of periodicals using an information system, a method for selecting several databases, which makes it possible to get a maximum coverage of primary sources with a certain amount of duplication, is proposed. Data on abstracting are obtained as the result of analyzing the input stream of approximately 700 databases and indices. Basic statistics for the abstracted stream are given for a number of companies: VINITI (All-Russia Institute for Scientific and Technical Information, Russian Academy of Sciences), CSA (Chemical Abstracts Service), Thomson Corporation, Elsevier, CABI Publishing, CAS (Cambridge Scientific Abstracts), and several others. A list of 25 of the largest abstract journals and referral databases, with respect to the number of periodicals represented in them, is given.  相似文献   
943.
The paper describes stages in the formation of the thesaurus of electronic commerce, the obtained practical results, and approaches to the evaluation of economic efficiency based on introducing the thesaurus into the information search system.  相似文献   
944.
The paper presents the results of the analysis of information sources, including both traditional print media and electronic resources on ecological and economic problems available on Internet sites. The most significant printed periodicals and Internet sites are determined in a given subject field. The possibility is considered of finding necessary information from an Internet resource with the help of the hypertext structure on the site of the information-retrieval system Ecological Information.  相似文献   
945.
In the context of system analysis, the architecture of a computerized information retrieval system adjusted to a support professional problem-oriented interactive documentary retrieving is considered. In addition to standard and extended retrieval capabilities, such a system must contain aids for generating and systematizing information files, generating and using components for linguistic support, and aids for estimating and analyzing the results of the retrieval.  相似文献   
946.
The triple jump is a demanding field event in which a jumper must tolerate extremely high impact forces while maintaining high horizontal speed. The present study was designed to clarify the mechanical loading characteristics and the role of neuromuscular function in the triple jump. Seven national triple jumpers (4 males, 3 females) volunteered to perform 3-6 jumps. The mean best performances were 14.32+/-0.45 m and 11.90+/-0.28 m for males and females, respectively. The three longest triple jumps for each jumper were selected for final analysis. The mean contact times were 0.139 s (hop), 0.157 s (step) and 0.177 s (jump). The largest ground reaction forces were observed in the step (15.2 times body weight), while the highest peak pressures were recorded under the heel and forefoot. The plantar pressure of the lateral side of the forefoot was highly related to the length of the triple jump (P < 0.05-0.01). In addition, electromyograms of both legs Suggested that mechanical loading places high demands on the neuromuscular system, as characterized by the high rate of activation in the pre-activity phase followed by high eccentric activity. Thus, the high activities of the gastrocnemius, vastus lateralis and hip extensor muscles seem to play an important role in preventing unnecessary yielding of the jumper during the braking phase.  相似文献   
947.
948.
949.
Accelerometers record total physical activity and time spent at different intensities. Pedometers indicate total activity only. The aim of this study was to assess the relationship between pedometer counts and attainment of > or = 60 min of moderate activity. Thirty-four children, ages 8-10 years, wore a Tritrac accelerometer and Yamax pedometer. Published recommendations of steps per day were compared to attainment of > or = 60 min moderate activity. Boys who accumulated 13,000 steps.d(-1) and girls who accumulated 12,000 steps.d(-1) engaged in > or = 60 min moderate activity. However, 23% of boys and 15% of girls did not reach the pedometer thresholds but did engage in > or = 60 min moderate activity. In conclusion, these pedometer thresholds provide a reasonable estimation when assessment of physical activity intensity is not possible.  相似文献   
950.
Der Artikel untersucht, wie Probleme, die speziell beim Unit-Testen objektorientierter Programme auftreten, mit Hilfe des Paradigmas aspektorientierte Programmierung gel?st werden k?nnen. Die Untersuchung stellt Schritt für Schritt die einzelnen Teilprobleme vor, f"uhrt konventionelle L?sungen auf, zeigt aspektorientierte Alternativen für die gestellten Probleme und erl"autert anhand von Code-Beispielen ihre Implementierung in der Sprache AspectJ.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号