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   7704篇
  免费   83篇
  国内免费   5篇
教育   5290篇
科学研究   956篇
各国文化   71篇
体育   483篇
综合类   2篇
文化理论   51篇
信息传播   939篇
  2021年   66篇
  2020年   85篇
  2019年   142篇
  2018年   190篇
  2017年   160篇
  2016年   154篇
  2015年   100篇
  2014年   130篇
  2013年   1345篇
  2012年   140篇
  2011年   140篇
  2010年   126篇
  2009年   112篇
  2008年   141篇
  2007年   110篇
  2006年   124篇
  2005年   101篇
  2004年   119篇
  2003年   104篇
  2002年   91篇
  2001年   125篇
  2000年   123篇
  1999年   109篇
  1998年   74篇
  1997年   76篇
  1996年   96篇
  1995年   72篇
  1994年   63篇
  1993年   97篇
  1992年   126篇
  1991年   127篇
  1990年   119篇
  1989年   107篇
  1988年   104篇
  1987年   114篇
  1986年   102篇
  1985年   116篇
  1984年   97篇
  1983年   103篇
  1982年   108篇
  1981年   77篇
  1980年   78篇
  1979年   107篇
  1978年   96篇
  1977年   90篇
  1976年   82篇
  1974年   69篇
  1973年   73篇
  1972年   60篇
  1971年   60篇
排序方式: 共有7792条查询结果,搜索用时 0 毫秒
21.
22.
23.
This paper reviews the current situation in library school education for medical librarianship in the United States and Canada based on information from a questionnaire sent to teachers of courses in medical librarianship in accredited library schools. Since 1939, when the first course devoted entirely to medical librarianship was offered at Columbia University, courses have been introduced into the curricula of at least forty-seven of the ALA-accredited library schools. In 1978 there were seventy courses available through forty-seven library schools. Possibilities for specialization in medical librarianship are examined. Course content is reviewed. Implications of the MLA certification examination for library school courses are explored.  相似文献   
24.
This paper addresses several misunderstandings about the nature of the FBI's Central Records System. Although depicted in popular culture and much of FBI historiography as a tool for the Cold War suppression of American radicals, the FBI's records system grew out of Department of Justice systems already in place before J. Edgar Hoover became Director in 1924. The system grew in size and complexity according to the demands placed on it by the changing priorities of the FBI's criminal and intelligence missions, guided by a “progressive” drive for efficiency through centralization.  相似文献   
25.
ABSTRACT

Lighting a cultural heritage artifact requires balancing visual perception with preventive conservation, by providing the best lighting (in terms of spectral distribution and quantity) to enable the viewer to appreciate details and color, while limiting photo-induced degradation. The paper outlines the methodology applied by a multi-disciplinary team while lighting the Shroud of Turin at its last public exhibition in 2015. The methodology considered the special requirements of the Shroud, including exposure to ultraviolet light, while providing appropriate display conditions that would meet audience expectations. The desired appearance (readability of the body image and color) was defined with the help of Shroud researchers and confirmed by subjective tests, while appropriate light levels for preservation were set in agreement with standard requirements and using knowledge of the degradation of linen in visible and UV light. The installation provided a controlled environment and a managed visitor route to the Shroud, assuring excellent perception of both details and color, with the lowest illuminance level about 15?lx.  相似文献   
26.
27.
Tracing the closure of oceans with irregular margins and the formation of an orocline are crucial for understanding plate reconstruction and continental assembly.The eastern Central Asian Orogenic Belt,where the Mongol-Okhotsk orocline is situated,is one of the world’s largest magmatic provinces.Using a large data set of U-Pb zircon ages,we updated the timing of many published igneous rocks,which allowed us to recognize tightly ’folded’ linear Carboniferous-Jurassic magmatic belts that wrap arou...  相似文献   
28.
29.
30.
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