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   7483篇
  免费   188篇
各国政治   451篇
工人农民   332篇
世界政治   464篇
外交国际关系   295篇
法律   4540篇
中国政治   43篇
政治理论   1496篇
综合类   50篇
  2020年   74篇
  2019年   95篇
  2018年   126篇
  2017年   151篇
  2016年   155篇
  2015年   114篇
  2014年   149篇
  2013年   834篇
  2012年   154篇
  2011年   163篇
  2010年   154篇
  2009年   150篇
  2008年   190篇
  2007年   201篇
  2006年   204篇
  2005年   162篇
  2004年   150篇
  2003年   175篇
  2002年   136篇
  2001年   278篇
  2000年   235篇
  1999年   231篇
  1998年   99篇
  1997年   87篇
  1996年   74篇
  1995年   70篇
  1994年   78篇
  1993年   70篇
  1992年   123篇
  1991年   162篇
  1990年   157篇
  1989年   143篇
  1988年   155篇
  1987年   171篇
  1986年   164篇
  1985年   156篇
  1984年   140篇
  1983年   124篇
  1982年   87篇
  1981年   97篇
  1980年   71篇
  1979年   130篇
  1978年   90篇
  1977年   74篇
  1976年   58篇
  1975年   83篇
  1974年   88篇
  1973年   83篇
  1972年   60篇
  1971年   57篇
排序方式: 共有7671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.
In the late nineteenth and early twentieth centuries, throughout the Pacific Rim, European and American colonizers reorganized indigenous systems of property rights in land to make them look more like European property systems, with disastrous effects for the indigenous people involved. The very first of these schemes, however, was the Māhele of 1845–1855, which took place not in a colony but in the independent Kingdom of Hawaii. Why did the Hawaiians do this to themselves? I argue that the Māhele was a sophisticated and partially successful response to the prospect that Hawaii would soon be colonized. The object of the Māhele was to ensure that in the event of annexation, Kamehameha III and other elite Hawaiians would not be dispossessed of their landholdings. The strategy was to convert those landholdings into a legal form that would be recognized by an incoming colonial government—whether American, British, or French—as private property.  相似文献   
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.
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   
26.
27.
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   
28.
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   
29.
Comparison of a suspected biter's dental arches with the patterned injury of a bite mark is especially difficult when the bite occurs in an anatomic location with a small radius of curvature or with complex or compound curves. The authors present two case reports in which human skin was used as a template for the reproduction of a bite. In one case the victim's skin was used; in the other, the skin of a anatomically similar person was used. The use of inked dental casts, photography, and transparent overlays significantly reduced the errors common to analysis of bite marks in these highly curved areas.  相似文献   
30.
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   
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