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   8222篇
  免费   222篇
各国政治   471篇
工人农民   477篇
世界政治   520篇
外交国际关系   324篇
法律   4908篇
中国政治   51篇
政治理论   1636篇
综合类   57篇
  2020年   87篇
  2019年   109篇
  2018年   143篇
  2017年   171篇
  2016年   178篇
  2015年   125篇
  2014年   157篇
  2013年   918篇
  2012年   183篇
  2011年   197篇
  2010年   179篇
  2009年   181篇
  2008年   223篇
  2007年   227篇
  2006年   239篇
  2005年   190篇
  2004年   177篇
  2003年   203篇
  2002年   176篇
  2001年   302篇
  2000年   258篇
  1999年   238篇
  1998年   108篇
  1997年   95篇
  1996年   87篇
  1995年   80篇
  1994年   90篇
  1993年   80篇
  1992年   138篇
  1991年   179篇
  1990年   167篇
  1989年   155篇
  1988年   163篇
  1987年   178篇
  1986年   171篇
  1985年   160篇
  1984年   139篇
  1983年   128篇
  1982年   95篇
  1981年   98篇
  1980年   79篇
  1979年   137篇
  1978年   95篇
  1977年   78篇
  1976年   60篇
  1975年   85篇
  1974年   91篇
  1973年   86篇
  1972年   57篇
  1971年   61篇
排序方式: 共有8444条查询结果,搜索用时 15 毫秒
21.
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   
22.
23.
24.
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   
25.
26.
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   
27.
28.
Attributions of blame for the first and latest episodes of violence were assessed in a sample of 139 couples who were referred to a mandatory domestic violence treatment program in the military. Use of a methodology which allows for reports of nonmutually exclusive categories of attribution from both members of the dyad revealed more complex patterns of attributions than reflected in the existing literature. In addition, there were low rates of agreement within couples as to who was to blame for the violence. Although both men and women exhibited a high frequency of blaming their partner for both episodes of violence, men were significantly more likely to blame themselves for the latest than for the first episode. Attributions of blame were related to contextual variables in both men and women. Sex specific relationships emerged. These results were discussed with specific reference to predictions derived from attribution theory and their clinical implications.  相似文献   
29.
A minisatellite probe, MZ 1.3, detecting hypervariable fragment patterns was isolated from a human genomic library. A repetitive sequence of 27 bp length was identified which is contained in the probe approx. 40 times. The MZ 1.3 repeat shows variable homology of 53-73% to the repetitive sequence of the protein III gene of the bacteriophage M13 genome. Polymorphic restriction fragment patterns were found with MZ 1.3 using the enzymes Hinf I, BstN I, Hae III, Mbo I, PstI/Pvu II, and Rsa I. An average of 18 polymorphic fragments was observed using Hinf I as enzyme. The band sharing frequency after Hinf I digestion among unrelated individuals was determined to be 23.8 +/- 7.2%. An example for the application of MZ 1.3 to paternity testing in an incest case is given. The probe can be used with radioactive or non-radioactive detection systems. An approach is presented to compare polymorphic fragment patterns from individuals obtained by independent gel runs on the basis of relative band positions (RBP) and calculated in a computerized analysis.  相似文献   
30.
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