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   10479篇
  免费   262篇
各国政治   670篇
工人农民   434篇
世界政治   743篇
外交国际关系   458篇
法律   5794篇
中国共产党   1篇
中国政治   55篇
政治理论   2496篇
综合类   90篇
  2020年   118篇
  2019年   135篇
  2018年   182篇
  2017年   211篇
  2016年   242篇
  2015年   160篇
  2014年   207篇
  2013年   1334篇
  2012年   213篇
  2011年   244篇
  2010年   236篇
  2009年   233篇
  2008年   272篇
  2007年   297篇
  2006年   282篇
  2005年   245篇
  2004年   240篇
  2003年   266篇
  2002年   284篇
  2001年   354篇
  2000年   308篇
  1999年   306篇
  1998年   158篇
  1997年   151篇
  1996年   127篇
  1995年   108篇
  1994年   110篇
  1993年   112篇
  1992年   171篇
  1991年   216篇
  1990年   194篇
  1989年   189篇
  1988年   191篇
  1987年   208篇
  1986年   214篇
  1985年   192篇
  1984年   157篇
  1983年   172篇
  1982年   121篇
  1981年   123篇
  1980年   95篇
  1979年   148篇
  1978年   107篇
  1977年   93篇
  1976年   79篇
  1975年   98篇
  1974年   113篇
  1973年   93篇
  1972年   68篇
  1971年   71篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
32.
Boubou     
HYDE  H. P. T. 《African affairs》1948,47(187):114-116
He was only a little monkey, a very little one the first timeI saw him, not more than 9 inches tall; and when he died 3 yearslater, fully grown, he did not measure more than a foot anda half.  相似文献   
33.
A simple and sensitive method is described for quantitative analysis of chlorpromazine in blood, serum, urine and tissue homogenate. The chlorpromazine cation radical produced by adding perchloric acid and 2,3-dichloro-5,6-dicyano-p-benzoquinone to the sample can be detected by the ESR method at room temperature. The sensitivity limit is 10 ng, that is, 20 μl of the solution containing 0.5 μg chlorpromazine/ml. The time needed for the measurement is within 10 min. The chlorpromazine radical thus produced is very stable; for example, 95% of the radical was observed after 24 h. The advantage of this method is discussed by comparing with the ordinary spectrophotometry which requires the purification of the sample.  相似文献   
34.
35.
36.
37.
What Do Prosecutors Maximize? Evidence from the Careers of U.S. Attorneys   总被引:1,自引:0,他引:1  
This study examines the performance of chief federal prosecutors(U.S. attorneys) and their subsequent careers. In a sample of570 attorneys in office from 1969 to 2000, the length of prisonsentences is positively related to subsequent favorable careeroutcomes for U.S. attorneys. In contrast, conviction rates donot appear to affect the careers of U.S. attorneys. These resultsare consistent with longer total prison sentences’ beingpersonally beneficial to prosecutors, and prosecutors’maximizing the length of prison sentences. Overall, the resultssuggest that sentence length, as opposed to convictions rates,is the relevant performance metric.  相似文献   
38.
We investigated the differences in the levels of carboxyhemoglobin (COHb), cyanide (HCN) and petroleum fuels (gasoline and kerosene) between left and right ventricular bloods from fire victims. COHb was slightly, and HCN and petroleum fuels were markedly higher levels in the left than those in the right. These effects were so called 'first pass phenomena' due to the circulation, diffusion and metabolization before the deaths of fire victims.  相似文献   
39.
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   
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