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   8757篇
  免费   281篇
各国政治   426篇
工人农民   307篇
世界政治   728篇
外交国际关系   352篇
法律   4898篇
中国共产党   1篇
中国政治   89篇
政治理论   2160篇
综合类   77篇
  2020年   100篇
  2019年   126篇
  2018年   200篇
  2017年   193篇
  2016年   188篇
  2015年   148篇
  2014年   176篇
  2013年   1078篇
  2012年   193篇
  2011年   233篇
  2010年   197篇
  2009年   205篇
  2008年   229篇
  2007年   238篇
  2006年   258篇
  2005年   217篇
  2004年   220篇
  2003年   225篇
  2002年   198篇
  2001年   249篇
  2000年   205篇
  1999年   185篇
  1998年   128篇
  1997年   117篇
  1996年   90篇
  1995年   101篇
  1994年   101篇
  1993年   111篇
  1992年   142篇
  1991年   171篇
  1990年   153篇
  1989年   163篇
  1988年   156篇
  1987年   191篇
  1986年   158篇
  1985年   180篇
  1984年   153篇
  1983年   159篇
  1982年   118篇
  1981年   107篇
  1980年   100篇
  1979年   110篇
  1978年   98篇
  1977年   77篇
  1976年   81篇
  1975年   81篇
  1974年   83篇
  1973年   83篇
  1972年   67篇
  1969年   62篇
排序方式: 共有9038条查询结果,搜索用时 0 毫秒
31.
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 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   
34.
Although law enforcement agencies across the nation have assumed part of the responsibility in the fight against terrorism, significant confusion exists as to the role of local law enforcement. While some agencies have taken steps towards terrorism prevention, little data has been collected on which agencies have taken the greatest steps, how those agencies have changed, and how other agencies should direct their activity. This case study of law enforcement census data from a single state considered variations in terrorism preparedness and predictors of preparedness. Agency size, presence of funding, and other variables significantly predict levels of terrorism preparedness. Important policy implications such as the distribution of funding and which agencies should be working towards terrorism preparedness 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.
37.
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   
38.
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   
39.
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