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   77818篇
  免费   3316篇
各国政治   4598篇
工人农民   3164篇
世界政治   6573篇
外交国际关系   3955篇
法律   39681篇
中国共产党   14篇
中国政治   784篇
政治理论   21410篇
综合类   955篇
  2021年   438篇
  2020年   1206篇
  2019年   1565篇
  2018年   1829篇
  2017年   2136篇
  2016年   2320篇
  2015年   1891篇
  2014年   2140篇
  2013年   10686篇
  2012年   1883篇
  2011年   2068篇
  2010年   1985篇
  2009年   2189篇
  2008年   2066篇
  2007年   2040篇
  2006年   2199篇
  2005年   2078篇
  2004年   1946篇
  2003年   1719篇
  2002年   1805篇
  2001年   2161篇
  2000年   1922篇
  1999年   1625篇
  1998年   1253篇
  1997年   1068篇
  1996年   1062篇
  1995年   1014篇
  1994年   1037篇
  1993年   1058篇
  1992年   1217篇
  1991年   1273篇
  1990年   1189篇
  1989年   1243篇
  1988年   1212篇
  1987年   1215篇
  1986年   1249篇
  1985年   1254篇
  1984年   1116篇
  1983年   1139篇
  1982年   958篇
  1981年   911篇
  1980年   728篇
  1979年   843篇
  1978年   652篇
  1977年   589篇
  1976年   529篇
  1975年   471篇
  1974年   499篇
  1973年   500篇
  1972年   430篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
881.
882.
883.
884.
885.
The Iran-Contra affair is an example of the type of event that is expected to give rise to a rally of public opinion behind the president. However, the public's response to this event, uncharacteristically, was a sharp decrease in support for President Reagan. This case study constitutes an attempt to explore the sources of the public opinion response to foreign policy events. Statements of political elites, news coverage and commentary, and public opinion assessments are examined to test the patriotism, priming, and opinion leadership explanations of the rally phenomenon. The actions of opinion leaders appears to provide the best explanation of the differential public response to the Iran-Contra affair.  相似文献   
886.
We report seven fatalities resulting from the ingestion of illicit drugs packaged in condoms, rubber balloons, or plastic bags which were observed in the last 4 years at the Office of the Chief Medical Examiner, State of Maryland. All the victims, with the exception of one, were men ranging in age from 19 to 37 years. There was no racial predominance. No drug paraphernalia was found at any scene. In two cases, seizure-like activity was documented. One victim had recently returned from Nigeria; therefore, Lassa fever was initially suspected. Two of the victims were "body packer" contrabanders who had just arrived from Africa. They used body cavities to hide large amounts of heroin to avoid U.S. Customs. The other five cases were "mini-packers," small-time illicit drug dealers who had swallowed a single bag of cocaine to avoid police detection. The possible mechanism of leaking or rupture of the latex container is discussed.  相似文献   
887.
Analysis of a sample of 1108 radii corresponding to 567 black and white North Americans in the Terry Collection at the Smithsonian Institution demonstrates that the diameter of the radial head is an accurate sex discriminator for human remains. A simple "radial-head method" of sex determination consists of measuring the maximum and minimum diameters of the head and comparing such measurements with the test cutoff points. The subject is female when the maximum radial head diameter (either left or right) is less than or equal to 21 mm, and male when the maximum diameter (either left or right) is greater than or equal to 24 mm. The same decisions apply to the minimum diameters of 20 mm or less and 23 mm or more, respectively. When the maximum diameter is 23 mm or the minimum is 22 mm, the subject is more likely male; when the maximum diameter is 22 mm or the minimum is 21 mm, the subject is more likely female. The sample frequency of any one of these latter diameters is never more than 16%. Cross-validation of the method with a sample of 50 pairs of radii of the Terry Collection, different from the original specimens, resulted in 92% sexing accuracy when using the left radius singly, 94% accuracy when using the right radius singly, and 96% accuracy when using both radii jointly.  相似文献   
888.
During preliminary examination of the body of a homicide victim, a peculiar red "fiber" was noticed and recovered. Initially believing this to be a carpet fiber, the item was subjected to fiber analysis. It was found to be a short coiled particle not like any known natural or synthetic fabric fiber. Subsequent examinations determined this "fiber" to be the larva of a common freshwater midge (Diptera; Chironomidae). Chironomid larvae have been observed on other bodies recovered from freshwater environments. Entomological studies of this organism have led to the conclusion that the presence of chironomid larvae indicates submersion of the body.  相似文献   
889.
Isoenzyme band patterns of animal blood erythrocyte acid phosphatase (EAP) and phosphoglucomutase-1 (PGM) were studied by isoelectric focusing on ultrathin polyacrylamide gels. For blood from all animals tested (dog, cat, cow, sheep, and goat), the overall band patterns for both isoenzymes were different from those of the most common human types of these enzymes, although some animal EAP and PGM bands appeared in the human band areas. When mixtures of human and animal red blood cells were studied, it was found that misinterpretation of human types was possible only if the overall band pattern of the mixtures was ignored. For the animal blood tested, the strong PGM bands appearing outside the human band areas could be used as "markers" for the possible presence of animal blood in the samples tested.  相似文献   
890.
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