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   7161篇
  免费   226篇
各国政治   389篇
工人农民   251篇
世界政治   581篇
外交国际关系   253篇
法律   4167篇
中国政治   42篇
政治理论   1635篇
综合类   69篇
  2020年   81篇
  2019年   108篇
  2018年   169篇
  2017年   149篇
  2016年   157篇
  2015年   105篇
  2014年   117篇
  2013年   805篇
  2012年   151篇
  2011年   169篇
  2010年   163篇
  2009年   157篇
  2008年   165篇
  2007年   174篇
  2006年   196篇
  2005年   164篇
  2004年   156篇
  2003年   175篇
  2002年   158篇
  2001年   216篇
  2000年   189篇
  1999年   165篇
  1998年   103篇
  1997年   97篇
  1996年   71篇
  1995年   80篇
  1994年   80篇
  1993年   87篇
  1992年   125篇
  1991年   154篇
  1990年   135篇
  1989年   149篇
  1988年   130篇
  1987年   156篇
  1986年   143篇
  1985年   158篇
  1984年   138篇
  1983年   146篇
  1982年   111篇
  1981年   98篇
  1980年   91篇
  1979年   102篇
  1978年   77篇
  1977年   63篇
  1976年   67篇
  1975年   62篇
  1974年   70篇
  1973年   73篇
  1969年   57篇
  1966年   57篇
排序方式: 共有7387条查询结果,搜索用时 15 毫秒
31.
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   
32.
The Green River Murder Investigation in King County, Washington, is currently the longest active serial murder investigation in U.S. history. During its course, over 26 separate scenes with from one to five victims each have been processed. The experience of the authors is presented in order to acquaint other agencies with techniques of outdoor scene processing that have evolved during recovery of remains from Green River and other skeletal cases.  相似文献   
33.
The absence of a thoroughly developed, working class critique of criminological theory has resulted in bias in the creation of knowledge regarding crime and deviance. Much as feminist writings illuminated the unique problems related to gender, and works by those discussing racial and ethnic minorities highlighted the special concerns related to race and ethnicity, a working class perspective can expose the particular issues having to do with class. A brief discussion will be presented dealing with the portrayal of working class people in the media, and the complicity of academia in allowing working class stereotypes to persist. A sketch of a working class perspective will then be developed, and it will be used to critique fourteen of the major criminological theories today in terms of their relative sensitivities and considerations of the class factor in crime and justice issues. The final section places each of the fourteen theories on a continuum from those that do not consider the working class experience at all to those that give the working class experience full consideration. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
34.
The population-adjusted rate of teenage suicide in King County, Washington, was reviewed for the 26 years from 1959 to 1984. For the entire period, the rate did not change significantly. An abrupt change did occur during the middle of this period, but, for reasons discussed in the text, this may well represent a change in procedures and philosophy of death certification rather than a real change in rate. Reasons for the apparent discrepancy with national statistics are discussed.  相似文献   
35.
In the statistical interpretation of forensic glass evidence it is standard practice to make the assumption of homogeneity of the refractive index (RI) of the source glass, or of localized homogeneity. However, the work of Locke and Hayes showed that, for toughened windscreen glass, this assumption might not be true. This work is well cited, but there appears to have been little follow-on published research. Furthermore, the toughening process is something known to affect the refractive index, and is a process that float glass does not undergo. Float glass is a major component of casework in New Zealand and for that reason it would be interesting to know whether the findings of Locke and Hayes apply when dealing with float glass. In this paper we describe an experiment similar to that of Locke and Hayes, systematically examining the variation of RI in a pane of float window glass. It was found that, although there were no systematic differences in refractive index, there were observable differences across the pane.  相似文献   
36.
In the wake of the 1990 amendments to the Clean Air Act, localities across the United States initiated public information campaigns both to raise awareness of threats to air quality and to change behavior related to air pollution by recommending specific behavioral changes in the campaign messages. These campaigns are designed to reduce the health hazards associated with poor air quality and to avoid federal sanctions resulting from the failure to meet air quality standards. As in many other communities across the country, a coalition of government agencies and businesses initiated a public information campaign in the Atlanta metropolitan region to reduce certain targeted behaviors, mainly driving. A two‐stage model used to analyze data from a rolling sample survey shows that the centerpiece of the information campaign—air quality alerts—was effective in raising awareness and reducing driving in a segment of the population. When the overall information campaign was moderated by employers' participation in programs to improve air quality, drivers significantly reduced the number of miles they drove and the number of trips they took by car on days when air quality alerts were sounded. Public information campaigns can be successful in increasing awareness, but changing well‐established behaviors, such as driving, is likely to require institutional mediation to provide social contexts that support the behavioral change, as well. © 2003 by the Association for Public Policy Analysis and Management.  相似文献   
37.
38.
Report of an unusual finding of bones on the shore of the Baltic Sea. Although the morphological findings appeared similar to a human foot skeleton, a quick identification as sea dog bone was possible.  相似文献   
39.
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   
40.
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