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   17520篇
  免费   754篇
各国政治   816篇
工人农民   607篇
世界政治   1468篇
外交国际关系   607篇
法律   11006篇
中国共产党   1篇
中国政治   90篇
政治理论   3574篇
综合类   105篇
  2021年   122篇
  2020年   288篇
  2019年   364篇
  2018年   428篇
  2017年   466篇
  2016年   467篇
  2015年   365篇
  2014年   414篇
  2013年   1834篇
  2012年   401篇
  2011年   481篇
  2010年   430篇
  2009年   449篇
  2008年   452篇
  2007年   422篇
  2006年   460篇
  2005年   406篇
  2004年   411篇
  2003年   400篇
  2002年   393篇
  2001年   664篇
  2000年   587篇
  1999年   441篇
  1998年   279篇
  1997年   231篇
  1996年   190篇
  1995年   191篇
  1994年   219篇
  1993年   216篇
  1992年   303篇
  1991年   361篇
  1990年   319篇
  1989年   341篇
  1988年   324篇
  1987年   329篇
  1986年   359篇
  1985年   345篇
  1984年   283篇
  1983年   298篇
  1982年   210篇
  1981年   207篇
  1980年   172篇
  1979年   224篇
  1978年   152篇
  1977年   133篇
  1976年   127篇
  1975年   100篇
  1974年   140篇
  1973年   139篇
  1972年   115篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
Correlation between plasma and bone marrow tricyclic antidepressants has not been studied before. Two groups of rabbits were given 10 and 20 mg of desipramine/kg body weight, respectively. Desipramine was administered to the animals once daily by mouth for 5 days. On the fifth day the animals were sacrificed and blood and bone marrow samples were collected and analyzed using a high performance liquid chromatographic (HPLC) method. Data showed that a correlation exists between bone marrow and blood desipramine. The bone marrow desipramine concentration increased as its blood levels increased. The average ratio of bone marrow to blood desipramine +/- S.D. (standard deviation) in both dosage groups was 37.2 +/- 4.46 with a range of 30.99-44.82. This investigation is promising and shows that bone marrow could be used as an alternative tissue in the absence of a suitable blood sample.  相似文献   
53.
The Green River Murder Investigation in King County, Washington, is currently the longest active serial murder investigation in U.S. history. During its course, over 26 separate scenes with from one to five victims each have been processed. The experience of the authors is presented in order to acquaint other agencies with techniques of outdoor scene processing that have evolved during recovery of remains from Green River and other skeletal cases.  相似文献   
54.
This article examines voluntary mediation and provides suggested criteria for attorneys in deciding whether or not to use mediation. The author discusses what mediation has to offer, what it takes to make it work, and important cautions for attorneys in deciding about the use of this process.  相似文献   
55.
In motorcycle accidents involving two riders, medicolegal identification of the driver is necessary when one or both riders die. It is particularly important in the latter case, because the survivor almost always insists that he or she was not driving. One characteristic injury that distinguishes the driver from the passenger is inguinal contusion-laceration (accompanied internally by pelvic fracture). This injury, caused by collision of the pelvis with the fuel tank, identifies the driver.  相似文献   
56.
57.
Kindergarten policy varies widely both across and within states. Over the past decade, a number of states have instituted a full‐day kindergarten requirement and others are considering it as a way to increase educational achievement. Many parents also support full‐day kindergarten as a source of child care. This paper uses the Early Child Longitudinal Study–Kindergarten Class of 1998–1999 to evaluate the efficacy of this policy. In ordinary least squares, probit, county fixed effects, and instrumental variables models, we find that there are initial benefits for students and the mothers of students who attend full‐day kindergarten, but that these differences largely evaporate by third grade. Contrary to claims by some advocates, attending full‐day kindergarten is found to have no additional benefit for students in families with income below the poverty threshold. © 2006 by the Association for Public Policy Analysis and Management  相似文献   
58.
The population-adjusted rate of teenage suicide in King County, Washington, was reviewed for the 26 years from 1959 to 1984. For the entire period, the rate did not change significantly. An abrupt change did occur during the middle of this period, but, for reasons discussed in the text, this may well represent a change in procedures and philosophy of death certification rather than a real change in rate. Reasons for the apparent discrepancy with national statistics are discussed.  相似文献   
59.
60.
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