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   11641篇
  免费   605篇
各国政治   501篇
工人农民   423篇
世界政治   901篇
外交国际关系   371篇
法律   7668篇
中国共产党   1篇
中国政治   81篇
政治理论   2253篇
综合类   47篇
  2023年   182篇
  2021年   113篇
  2020年   229篇
  2019年   270篇
  2018年   279篇
  2017年   351篇
  2016年   339篇
  2015年   286篇
  2014年   311篇
  2013年   1146篇
  2012年   277篇
  2011年   343篇
  2010年   322篇
  2009年   331篇
  2008年   313篇
  2007年   290篇
  2006年   297篇
  2005年   266篇
  2004年   271篇
  2003年   248篇
  2002年   254篇
  2001年   474篇
  2000年   441篇
  1999年   307篇
  1998年   192篇
  1997年   160篇
  1996年   131篇
  1995年   126篇
  1994年   151篇
  1993年   137篇
  1992年   206篇
  1991年   226篇
  1990年   211篇
  1989年   219篇
  1988年   207篇
  1987年   191篇
  1986年   236篇
  1985年   212篇
  1984年   165篇
  1983年   179篇
  1982年   116篇
  1981年   124篇
  1980年   87篇
  1979年   133篇
  1978年   76篇
  1977年   77篇
  1976年   72篇
  1974年   74篇
  1973年   68篇
  1972年   67篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
The United States today faces a loss of influence as a world power, a reduction in American independence as a policymaker, and a decline in the standard of living on which Americans have come to depend. History teaches that nations weaker and less productive than the United States can rise to become economic powerhouses and rapidly increase their standards of living. History also teaches that nations failing to recognize their fundamental problems will inevitably decline. American politicians must face what is abundantly clear: the United States is losing ground and must act quickly to reverse its course. This White Paper outlines what must be done. Information about the nation's current status must be analyzed and communicated. Incentives to improve the level of competence in government must be provided and maintained. The emphasis of government policy must be changed to reflect broad economic and technological interests as opposed to special interests. Savings must be encouraged and increased. Infrastructure must be improved Tax laws must be modified to help bring these changes about. Economic and technological issues must be elevated to the importance they require. American thinking must reflect the new realities: that the age of leadership through military power is over, that the requirements for success in the world of the 1990s and beyond require a sound and growing economy that is internationally competitive. The US can accomplish these goals only through foundation-shaking, comprehensive, fundamental changealong the lines we propose herein.This paper is the executive summary (with minor editing modifications) of a white paper that is available from Cornell University's Johnson Graduate School of Management.  相似文献   
93.
94.
95.
96.
Danger: implants     
The superheated debate over breast implants awakened a sleeping giant of an issue clouding "medical devices"--the government's clumsy nomenclature for any medical product that is not a drug, from breast implants and artificial hips to X-ray machines and surgical thread. Some 130 categories of high-risk devices are in use with little or no proof of safety, reliability or effectiveness. All appeared before 1976, the year that the Food and Drug Administration got the authority to regulate such products. Under activist chief David Kessler and with added clout from a 1990 law, the FDA plans to scrutinize the entire 130-item list. Five will get special attention starting early next year: saline-filled breast implants, inflatable penile implants, testicular implants, heart-bypass pumps and cranial stimulators. U.S. News has looked at all five devices, using FDA data obtained through the Freedom of Information Act. In-depth computer analysis suggested that penile implants deserve closer examination. Why is clear from the following report.  相似文献   
97.
98.
99.
100.
Isoenzyme band patterns of animal blood erythrocyte acid phosphatase (EAP) and phosphoglucomutase-1 (PGM) were studied by isoelectric focusing on ultrathin polyacrylamide gels. For blood from all animals tested (dog, cat, cow, sheep, and goat), the overall band patterns for both isoenzymes were different from those of the most common human types of these enzymes, although some animal EAP and PGM bands appeared in the human band areas. When mixtures of human and animal red blood cells were studied, it was found that misinterpretation of human types was possible only if the overall band pattern of the mixtures was ignored. For the animal blood tested, the strong PGM bands appearing outside the human band areas could be used as "markers" for the possible presence of animal blood in the samples tested.  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