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   7605篇
  免费   257篇
各国政治   384篇
工人农民   309篇
世界政治   604篇
外交国际关系   368篇
法律   4270篇
中国政治   37篇
政治理论   1790篇
综合类   100篇
  2023年   48篇
  2021年   48篇
  2020年   105篇
  2019年   130篇
  2018年   203篇
  2017年   179篇
  2016年   218篇
  2015年   127篇
  2014年   163篇
  2013年   862篇
  2012年   212篇
  2011年   231篇
  2010年   171篇
  2009年   201篇
  2008年   211篇
  2007年   232篇
  2006年   198篇
  2005年   189篇
  2004年   196篇
  2003年   182篇
  2002年   166篇
  2001年   282篇
  2000年   282篇
  1999年   207篇
  1998年   108篇
  1997年   108篇
  1996年   104篇
  1995年   97篇
  1994年   100篇
  1993年   87篇
  1992年   158篇
  1991年   151篇
  1990年   177篇
  1989年   161篇
  1988年   170篇
  1987年   148篇
  1986年   124篇
  1985年   133篇
  1984年   103篇
  1983年   92篇
  1982年   83篇
  1981年   83篇
  1980年   72篇
  1979年   63篇
  1978年   50篇
  1977年   34篇
  1976年   37篇
  1975年   40篇
  1974年   50篇
  1973年   35篇
排序方式: 共有7862条查询结果,搜索用时 15 毫秒
31.
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   
32.
33.
34.
35.
The enzyme activity of phosphoglucomutase (PGM) has been investigated in red cell haemolysates from 142 individuals and compared to the sub-type as determined by isoelectric focusing. The 10 phenotypes showed significant differences in PGM-activity which indicates that there is a correlation between the level of activity and the isolelectric point of homozygotes. No indication of silent alleles or alleles with reduced activity was found in this collective.  相似文献   
36.
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   
37.
38.
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   
39.
40.
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