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   17848篇
  免费   314篇
各国政治   679篇
工人农民   1537篇
世界政治   752篇
外交国际关系   579篇
法律   10654篇
中国共产党   4篇
中国政治   78篇
政治理论   3799篇
综合类   80篇
  2023年   56篇
  2020年   138篇
  2019年   187篇
  2018年   1467篇
  2017年   1408篇
  2016年   1224篇
  2015年   261篇
  2014年   216篇
  2013年   1161篇
  2012年   450篇
  2011年   1163篇
  2010年   1189篇
  2009年   815篇
  2008年   1008篇
  2007年   919篇
  2006年   312篇
  2005年   327篇
  2004年   437篇
  2003年   380篇
  2002年   271篇
  2001年   294篇
  2000年   286篇
  1999年   207篇
  1998年   149篇
  1997年   142篇
  1996年   137篇
  1995年   136篇
  1994年   129篇
  1993年   119篇
  1992年   187篇
  1991年   209篇
  1990年   186篇
  1989年   186篇
  1988年   169篇
  1987年   185篇
  1986年   181篇
  1985年   170篇
  1984年   173篇
  1983年   175篇
  1982年   104篇
  1981年   98篇
  1980年   81篇
  1979年   111篇
  1978年   85篇
  1977年   84篇
  1976年   64篇
  1975年   59篇
  1974年   63篇
  1973年   76篇
  1972年   63篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
981.
982.
The results are presented of extraction of 1-methyl-3,4-dioxybenzene, 1-methyl-2,5-dioxybenzene and 4-oxybenzene acid from aqueous solutions with hydrophobic and hydrophilic organic soluvants. It is shown that the degree of extraction depends on the nature of the extragents and pH of the aqueous phase medium. Extraction multiplicity for obtaining necessary quantities of the compounds is calculated.  相似文献   
983.
984.
By potential damage, chemical terroristic attacks are much more dangerous than terroristic bombing. To fight chemical terrorism it is necessary to create the system of medical-environmental defense of the population. In line with emergency medicine, forensic medical service is a very important element of the antiterroristic defense. The activity of forensic-medical experts in the field of terroristic chemical attack is analysed.  相似文献   
985.
986.
Despite the recent surge in society's interest in human violence, relatively few studies have been conducted examining the closely related phenomenon of animal cruelty. Although several researchers have begun to identify some of the correlates of animal cruelty, few have attempted to understand how differences in the backgrounds of rural and urban residents have led to their abuse of animals. Using survey data from 261 inmates, the authors investigate how demographic, familial differences and species type have contributed to the frequency of acts of animal cruelty. In general, early exposure to animal abuse is a strong predictor of the subsequent behavior. However, rural inmates learned to be cruel by watching family members exclusively, whereas urban inmates learned from family members and friends. Moreover, urban inmates chose dogs, cats, and wild animals as their target animals; however, rural inmates chose only cats.  相似文献   
987.
A meta-analytic review of research comparing biased and unbiased instructions in eyewitness identification experiments showed an asymmetry; specifically, that biased instructions led to a large and consistent decrease in accuracy in target-absent lineups, but produced inconsistent results for target-present lineups, with an average effect size near zero (Steblay, 1997). The results for target-present lineups are surprising, and are inconsistent with statistical decision theories (i.e., Green & Swets, 1966). A re-examination of the relevant studies and the meta-analysis of those studies shows clear evidence that correct identification rates do increase with biased lineup instructions, and that biased witnesses make correct identifications at a rate considerably above chance. Implications for theory, as well as police procedure and policy, are discussed.  相似文献   
988.
Four reality monitoring variables were used to discriminate suspect from foil identifications in 183 actual criminal cases. Four hundred sixty-one identification attempts based on five and six-person lineups were analyzed. These identification attempts resulted in 238 suspect identifications and 68 foil identifications. Confidence, automatic processing, eliminative processing and feature use comprised the set of reality monitoring variables. Thirty-five verbal confidence phrases taken from police reports were assigned numerical values on a 10-point confidence scale. Automatic processing identifications were those that occurred “immediately” or “without hesitation.” Eliminative processing identifications occurred when witnesses compared or eliminated persons in the lineups. Confidence, automatic processing and eliminative processing were significant predictors, but feature use was not. Confidence was the most effective discriminator. In cases that involved substantial evidence extrinsic to the identification 43% of the suspect identifications were made with high confidence, whereas only 10% of the foil identifications were made with high confidence. The results of a laboratory study using the same predictors generally paralleled the archival results. Forensic implications are discussed.  相似文献   
989.
990.
The growing need for organ and tissue transplants has led a number of states to enforce a policy that views a donor's declared intent to be an organ donor as legally binding. This allows health officials to harvest organs without the permission of the next of kin. Legally binding consent is controversial because of concerns that it may anger family members, lead to negative publicity, and discourage potential donors. We use interviews and a pooled time-series data set of cadaveric donation rates in U.S. states to evaluate the effectiveness of this policy. Our research indicates that enforcement of legally binding consent has marginally increased cadaveric donations while not significantly affecting donor registration. We also find evidence that the effect of the policy might be greater if it were more fully implemented and coordinated with efforts to improve public acceptance and awareness.  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