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   17239篇
  免费   503篇
各国政治   710篇
工人农民   670篇
世界政治   1470篇
外交国际关系   597篇
法律   10331篇
中国共产党   3篇
中国政治   85篇
政治理论   3702篇
综合类   174篇
  2020年   209篇
  2019年   248篇
  2018年   325篇
  2017年   390篇
  2016年   412篇
  2015年   287篇
  2014年   336篇
  2013年   1707篇
  2012年   410篇
  2011年   440篇
  2010年   351篇
  2009年   392篇
  2008年   448篇
  2007年   476篇
  2006年   471篇
  2005年   405篇
  2004年   403篇
  2003年   420篇
  2002年   383篇
  2001年   678篇
  2000年   614篇
  1999年   507篇
  1998年   286篇
  1997年   242篇
  1996年   206篇
  1995年   206篇
  1994年   251篇
  1993年   219篇
  1992年   338篇
  1991年   369篇
  1990年   325篇
  1989年   350篇
  1988年   318篇
  1987年   335篇
  1986年   337篇
  1985年   331篇
  1984年   287篇
  1983年   317篇
  1982年   257篇
  1981年   237篇
  1980年   182篇
  1979年   247篇
  1978年   165篇
  1977年   146篇
  1976年   131篇
  1975年   122篇
  1974年   135篇
  1973年   117篇
  1972年   112篇
  1971年   94篇
排序方式: 共有10000条查询结果,搜索用时 250 毫秒
51.
The results of additional validation studies of a sensitive microplate hemagglutination assay for ABO reverse grouping of bloodstains are presented. The results of the validation study demonstrate the reliability of the microplate assay for use in routine serological casework. Based on these studies, the microplate assay has now replaced the Lattes crust test for ABO reverse grouping of bloodstains in the FBI Laboratory.  相似文献   
52.
Blood previously acidified with aqueous saturated ammonium chloride solution was extracted with ethyl acetate. The dried extract was subjected to acetonitrile–hexane partition. The acetonitrile portion was analysed for the presence of acidic and neutral drugs by HPLC–DAD (200 mm×2.1 mm I.D. microbore ODS-Hypersil column) and GC–FID (25 m narrow-bore×0.25 mm I.D. HP-5 column with 0.33 μm film thickness). The protocol was found to be suitable for both clinical toxicology (including emergency toxicology) and postmortem toxicology. At least 66 drugs of interest were unequivocally identified by RRTs (HPLC) and UV spectra (DAD) match while another 12 were unequivocally identified by double RRTs match (HPLC and GC). Quantitation was facilitated by incorporating calibration blood standards in each assay batch. The five drugs most commonly encountered in clinical blood specimens (1150 cases) were: paracetamol (47.4% of the cases); chlormezanone (6.6%), theophylline (1.74%), naproxen (1.65%) and mefenamic acid (1.56%). The following drugs were detected in toxicologically significant quantities in postmortem blood specimens (245 cases): phenobarbitone (1.22% of the cases), naproxen (0.82%), chlormezanone (0.82%), theophylline (0.82%), carbamazepine (0.41%) and paracetamol (0.41%).  相似文献   
53.
54.
55.
56.
Abstract: Recent U.S. House elections have challenged existing models of congressional elections, raising the question of whether or not processes thought to govern previous elections are still at work. Taking Marra and Ostrom's (1989) model of congressional elections as representative of extant theoretical perspectives and testing it against recent elections, we find that the model fails. We augment Marra and Ostrom's model with new insights, constructing a model that explains elections from 1950 to 1998. We find that, although presidential approval ratings and major political events continue to drive congressional elections, the distribution of open seats must also be taken into account.  相似文献   
57.
This article discusses relevant literature on the potential benefits of sport, recreation, and leisure, and how these benefits relate to rehabilitation of juveniles. Many professionals involved in juvenile rehabilitation believe sport and recreation are beneficial adjuncts to treatment programming; however, it can be difficult to structure sport and recreation in ways that directly correspond to treatment goals. The purpose of this article is to provide insights for professionals working with juveniles on how sport and recreation programming can be an effective means of helping to achieve rehabilitation goals. Attention is given to approaches, particularly the Teaching Games for Understanding model (Bunker & Thorpe, 1982), which can be used to effectively link recreation and sport to the rehabilitation process.  相似文献   
58.
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