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   29760篇
  免费   1115篇
各国政治   1452篇
工人农民   1122篇
世界政治   2433篇
外交国际关系   1114篇
法律   17900篇
中国共产党   3篇
中国政治   240篇
政治理论   6326篇
综合类   285篇
  2020年   430篇
  2019年   495篇
  2018年   642篇
  2017年   734篇
  2016年   768篇
  2015年   604篇
  2014年   648篇
  2013年   3166篇
  2012年   703篇
  2011年   833篇
  2010年   687篇
  2009年   746篇
  2008年   762篇
  2007年   764篇
  2006年   736篇
  2005年   679篇
  2004年   717篇
  2003年   724篇
  2002年   625篇
  2001年   1144篇
  2000年   1045篇
  1999年   887篇
  1998年   480篇
  1997年   385篇
  1996年   359篇
  1995年   352篇
  1994年   402篇
  1993年   378篇
  1992年   565篇
  1991年   593篇
  1990年   536篇
  1989年   557篇
  1988年   524篇
  1987年   560篇
  1986年   547篇
  1985年   551篇
  1984年   478篇
  1983年   522篇
  1982年   388篇
  1981年   358篇
  1980年   288篇
  1979年   404篇
  1978年   288篇
  1977年   240篇
  1976年   224篇
  1975年   203篇
  1974年   223篇
  1973年   204篇
  1972年   186篇
  1971年   161篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
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   
103.
104.
Correlation between plasma and bone marrow tricyclic antidepressants has not been studied before. Two groups of rabbits were given 10 and 20 mg of desipramine/kg body weight, respectively. Desipramine was administered to the animals once daily by mouth for 5 days. On the fifth day the animals were sacrificed and blood and bone marrow samples were collected and analyzed using a high performance liquid chromatographic (HPLC) method. Data showed that a correlation exists between bone marrow and blood desipramine. The bone marrow desipramine concentration increased as its blood levels increased. The average ratio of bone marrow to blood desipramine +/- S.D. (standard deviation) in both dosage groups was 37.2 +/- 4.46 with a range of 30.99-44.82. This investigation is promising and shows that bone marrow could be used as an alternative tissue in the absence of a suitable blood sample.  相似文献   
105.
106.
The formation of adequate mental health systems within prisons has accelerated as a result of successful class action lawsuits. Our recent national survey questioned all state correctional departments about the existence of standards in each system, compliance with such standards, prevalence of class action lawsuits involving the issue of providing adequate mental health services for inmates, issues related to consent decrees, available mental health resources within the correctional system, and the administrative structure of the mental health system. Our purpose was to identify those factors correlated with certified class action lawsuits involving issues related to mental health services. Twenty-one states were involved in such litigation. Only the presence of psychiatric hospitals operated by the department of corrections correlated with the presence of certified class action lawsuits involving mental health services. Prison systems larger than 15,000 inmates were at higher risk for such litigation. Smaller systems having psychiatric hospitals run by the state mental health agency appeared to be at less risk for such litigation.  相似文献   
107.
Bone fragments were stored in water for 2 years at room temperature and investigated serologically using the following methods: Absorption-elution, extraction of blood group substances and immunohistochemistry (PAP). All 3 methods gave essentially specific results for fresh bone tissue but with putrid bone tissue unspecific reactions were found predominantly with the absorption-elution and PAP techniques. In contrast, more specific reactions were obtained from the extracts although they were much weaker. From this it can be concluded that pure physical binding plays a substantial role in the unspecific reaction between antibodies and bone material. It is suggested that the relevant physical properties are altered by putrification.  相似文献   
108.
Most studies that consider the factors influencing the decision to leave an abusive relationship rely on retrospective, self-report data. In addition to the biased samples that are frequently obtained in such investigations, the methodological shortcomings of survey research limit its explanatory power, particularly when applied to such sensitive topics as family violence. This report introduces an alternative method for studying the decision to leave an abusive relationship. Forty-five men and 68 women were studied using an experimental computer game of an abuse-like relationship. The tendency to leave this relationship was measured under four differing conditions of severity and frequency of abuse. A logit analysis revealed that the frequency of abuse was more consequential to women's decisions to leave, while severity of abuse was more salient for men. In addition, the hypothesized model, including frequency of abuse, severity of abuse, and locus of control, fits well for women but not for men. The implications of these findings, as well as the validity and future application of experimental games, are discussed.  相似文献   
109.
110.
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   
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