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   11706篇
  免费   160篇
各国政治   334篇
工人农民   534篇
世界政治   746篇
外交国际关系   468篇
法律   7073篇
中国共产党   34篇
中国政治   132篇
政治理论   2404篇
综合类   141篇
  2023年   60篇
  2021年   75篇
  2020年   177篇
  2019年   175篇
  2018年   242篇
  2017年   284篇
  2016年   332篇
  2015年   263篇
  2014年   259篇
  2013年   1004篇
  2012年   268篇
  2011年   325篇
  2010年   241篇
  2009年   314篇
  2008年   372篇
  2007年   409篇
  2006年   370篇
  2005年   339篇
  2004年   332篇
  2003年   285篇
  2002年   279篇
  2001年   385篇
  2000年   347篇
  1999年   275篇
  1998年   176篇
  1997年   132篇
  1996年   162篇
  1995年   130篇
  1994年   155篇
  1993年   146篇
  1992年   211篇
  1991年   266篇
  1990年   226篇
  1989年   211篇
  1988年   236篇
  1987年   214篇
  1986年   235篇
  1985年   207篇
  1984年   184篇
  1983年   168篇
  1982年   116篇
  1981年   131篇
  1980年   106篇
  1979年   108篇
  1978年   95篇
  1977年   81篇
  1976年   68篇
  1975年   75篇
  1974年   71篇
  1973年   83篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
3.
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   
4.
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   
5.
6.
7.
8.
A new solid-phase extraction procedure for the determination of cocaine and benzoylecgonine in amniotic fluid, using high flow co-polymeric sorbents is reported. The recoveries of cocaine and benzoylecgonine within the range 0.1-1 mg/l were 95.7% and 50.3%, respectively. The use of high-flow sorbents allowed the easy extraction of amniotic fluid regardless of sample viscosity or physical nature. The use of these solid-phase columns provided many advantages over the more commonly used solvent extraction, including an increase in extraction speed and efficiency, reduced operator time, reduced solvent use and disposal volumes and exceptional extract quality. Further, the determination of amniotic fluid obtained from pregnant cocaine users may provide important information about handling of cocaine by the fetus at various gestational ages. The procedure was successfully applied to amniotic fluid from suspected cocaine abusers.  相似文献   
9.
Presented in this paper are the initial results involving the use of the nose or outer ear as temperature measurement sites to determine the postmortem period of the human corpse. Simple mathematical models for both sites are developed based on cooling curves of five corpses. Analysis of errors between actual and calculated postmortem intervals suggest that in its present form, the described methods would not be suitable for use in accurately determining the time since death of human corpses.  相似文献   
10.
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