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   24341篇
  免费   417篇
  国内免费   26篇
教育   17304篇
科学研究   2126篇
各国文化   227篇
体育   2205篇
综合类   14篇
文化理论   196篇
信息传播   2712篇
  2022年   202篇
  2021年   299篇
  2020年   421篇
  2019年   652篇
  2018年   912篇
  2017年   876篇
  2016年   778篇
  2015年   459篇
  2014年   711篇
  2013年   4622篇
  2012年   704篇
  2011年   708篇
  2010年   534篇
  2009年   543篇
  2008年   590篇
  2007年   532篇
  2006年   479篇
  2005年   457篇
  2004年   403篇
  2003年   386篇
  2002年   375篇
  2001年   500篇
  2000年   410篇
  1999年   375篇
  1998年   224篇
  1997年   226篇
  1996年   248篇
  1995年   241篇
  1994年   186篇
  1993年   206篇
  1992年   326篇
  1991年   303篇
  1990年   308篇
  1989年   305篇
  1988年   261篇
  1987年   305篇
  1986年   273篇
  1985年   307篇
  1984年   257篇
  1983年   216篇
  1982年   194篇
  1981年   167篇
  1980年   158篇
  1979年   268篇
  1978年   188篇
  1977年   172篇
  1976年   155篇
  1975年   150篇
  1974年   151篇
  1971年   143篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
972.
973.
974.
Arming uninhabited vehicles (UVs) is an increasing trend. Widespread deployment can bring dangers for arms-control agreements and international humanitarian law (IHL). Armed UVs can destabilise the situation between potential opponents. Smaller systems can be used for terrorism. Using a systematic definition existing international regulation of armed UVs in the fields of arms control, export control and transparency measures is reviewed; these partly include armed UVs, but leave large gaps. For preventive arms control a general prohibition of armed UVs would be best. If that is unattainable, several measures should be taken. An explicit prohibition of autonomous attack, that is without a human decision, should be added to IHL. Concerning armed UVs remotely controlled by a human soldier, recommendations differ according to type or mission. New kinds of uninhabited nuclear-weapon carriers should be banned. Space weapons should be prohibited in general. UVs smaller than 0.2–0.5 m should be banned. Bigger remotely controlled armed UVs not equipped with weapons of mass destruction should be subject to numerical limitations in various categories. For these the Treaty on Conventional Armed Forces in Europe is an important precedent.  相似文献   
975.
This paper presents the results of a major investigation by questionnaire of author attitudes towards scholarly publishing, which was funded by the Publisher's Association. Altogether, the views of nearly 4,000 authors were obtained and this paper concerns just those thousand or so authors who accepted the invitation to write freely about their own personal feelings and experiences. Using QSR N6 textual analysis software, their comments were processed and themes extracted. While the rest of the questionnaire, which was formed of closed‐question, tick‐box type questions, clearly must have had some impact on their thinking, the authors had considerable latitude in regard to what they could say. The paper provides a unique opportunity to hear their views directly. The pressing topics turned out to be (in rough order of concern): the peer‐review system, copyright, journal prices, alternative business models for journal publishing, big deals, Elsevier, electronic publishing and digital journals.  相似文献   
976.
The paper is devoted to the problem of the qualitative training of management specialists. New methods and instruments permitting the quality of accepted decisions to be heightened are described. It is suggested to use an SISDM containing the functions of the system as an instrument for planning decisions and training in decision making with the use of computerized methods for the active teaching of the method for the analysis of concrete situations and management games.  相似文献   
977.
The pilot issue of the data collection of the All-Russian Institute of Scientific and Technical Information of the Russian Academy of Sciences “Industry of Nanosystems and Nanomaterials” gives an approximate view of the state of this field of science at the beginning of 2007. The topics of articles in the pilot issue are analyzed. The directions of development of nanotechnologies are shown. The basic types of nanomaterials, the methods of their production, and their properties and applications are given.  相似文献   
978.
In this paper, the consideration of the problem of the competitiveness of scientific research as an independent scientific line in the context of the science of science, whose main methodological instruments could be the adapted economic concepts of competitiveness and clusters, as well as mathematical models of competitive interactions (including models described in the terms and equations of population dynamics) and the methods of scientometric analysis, is proposed. It is shown that solution of the problem of increasing the competitiveness of post-Soviet scientific research falls within the domains of information communication. In addition, the role of the international movement for public access to scientific knowledge in increasing the competitiveness of scientific research is considered.  相似文献   
979.
980.
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