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   604篇
  免费   38篇
各国政治   35篇
工人农民   66篇
世界政治   34篇
外交国际关系   69篇
法律   277篇
中国政治   9篇
政治理论   148篇
综合类   4篇
  2023年   10篇
  2022年   3篇
  2021年   10篇
  2020年   19篇
  2019年   23篇
  2018年   35篇
  2017年   41篇
  2016年   39篇
  2015年   28篇
  2014年   27篇
  2013年   104篇
  2012年   25篇
  2011年   39篇
  2010年   16篇
  2009年   18篇
  2008年   18篇
  2007年   19篇
  2006年   14篇
  2005年   17篇
  2004年   20篇
  2003年   10篇
  2002年   8篇
  2001年   10篇
  2000年   9篇
  1999年   4篇
  1998年   6篇
  1997年   3篇
  1996年   8篇
  1995年   9篇
  1994年   5篇
  1993年   2篇
  1992年   6篇
  1991年   6篇
  1990年   4篇
  1989年   4篇
  1988年   4篇
  1987年   3篇
  1986年   3篇
  1985年   1篇
  1983年   3篇
  1982年   2篇
  1980年   1篇
  1978年   4篇
  1970年   1篇
  1967年   1篇
排序方式: 共有642条查询结果,搜索用时 15 毫秒
191.
We develop an approach to conducting large-scale randomized public policy experiments intended to be more robust to the political interventions that have ruined some or all parts of many similar previous efforts. Our proposed design is insulated from selection bias in some circumstances even if we lose observations; our inferences can still be unbiased even if politics disrupts any two of the three steps in our analytical procedures; and other empirical checks are available to validate the overall design. We illustrate with a design and empirical validation of an evaluation of the Mexican Seguro Popular de Salud (Universal Health Insurance)program we are conducting. Seguro Popular, which is intended to grow to provide medical care, drugs, preventative services, and financial health protection to the 50 million Mexicans without health insurance, is one of the largest health reforms of any country in the last two decades. The evaluation is also large scale, constituting one of the largest policy experiments to date and what may be the largest randomized health policy experiment ever.  相似文献   
192.
193.
194.
Studies on ballistic trauma to the ribs and thorax, cranium, and long bones demonstrate the potential of obtaining a bullet caliber from an entrance wound. In order to validate prior research on caliber estimation in bone tissue and assess the viability of bullet type determination based on the macroscopic evidence at the entrance wound, thirty fleshed pork (Sus scrofa) shoulders (humeri) were shot with either lead or copper jacketed bullets in one of three calibers; 0.22, 9 mm, or 0.38. Overall, our findings are consistent with previous research indicating that calibers can be grouped into “small” and “large” categories. Bullet type, lead or copper jacket, can be ascertained based on cortical flaking and the analysis of materials deposited around the entry wound. The addition of this evidence holds value in cases where no firearm or ballistic evidence is recovered from a crime scene.  相似文献   
195.
196.
This study examined the effects of fire on the features associated with saw marks in bone. Both class and individual characteristics were examined using stereomicroscopy and scanning electron microscopy (SEM). Twenty-four semifleshed Sus scrofa L. tibiae were sawed into three sections with the middle section having deep and shallow false starts. Twelve saw blades of varying age and type were each used to cut two tibiae. In each case, the first tibia was burned in an outdoor open fire to the point of partial calcination. The second tibia, our control, was macerated using a heated enzyme solution. Controls and burned specimens were examined for the following characteristics: breakaway spur, tooth hop, false start, exit chipping, tooth imprint, breakaway notch, pull out striae, kerf flare, and blade drift. In general, there was parity in the observed characteristics in the burned samples using the SEM and the stereomicroscope. SEM observation, however, provided enhanced images, with the addition of observing individual tooth imprints, previously not visible. Therefore, this study recommends using an SEM for the examination of saw cuts in burnt bone.  相似文献   
197.
A blind study to determine whether virtual toolmarks created using a computer could be used to identify and characterize angle of incidence of physical toolmarks was conducted. Six sequentially manufactured screwdriver tips and one random screwdriver were used to create toolmarks at various angles. An apparatus controlled tool angle. Resultant toolmarks were randomly coded and sent to the researchers, who scanned both tips and toolmarks using an optical profilometer to obtain 3D topography data. Developed software was used to create virtual marks based on the tool topography data. Virtual marks generated at angles from 30 to 85° (5° increments) were compared to physical toolmarks using a statistical algorithm. Twenty of twenty toolmarks were correctly identified by the algorithm. On average, the algorithm misidentified the correct angle of incidence by ?6.12°. This study presents the results, their significance, and offers reasons for the average angular misidentification.  相似文献   
198.
Few political institutions are as central to theories of lawmaking as the executive veto. Despite its importance, institutional continuity at the national level has precluded identification of empirical effects of the veto on legislative behavior. We address this limitation and present evidence from the states demonstrating how the veto affects the formation of legislative coalitions and, indirectly, executive influence over policymaking. We find consistent evidence that the presence and strength of gubernatorial veto powers affect the lawmaking behavior of state legislatures. Our analysis shows how institutional provisions condition executives' ability to affect policy outcomes in separation‐of‐powers systems.  相似文献   
199.
200.
Increasing public awareness of cyberbullying, coupled with several highly publicized youth suicides linked to electronic bullying, have led lawmakers and politicians to consider new criminal legislation specifically related to cyberbullying. However, little is known about how the police currently respond to cyberbullying, and it is not clear whether new laws are necessary. In this article, the authors draw upon in-depth interviews with Canadian street patrol officers and school resource officers to explore police perspectives on policing cyberbullying. In contrast to the reactive hard-line approach proposed in much legislation and public discussion, police officers prefer to take a preventative approach by educating youth and raising awareness about the dangers of digital communications. Although there are instances when criminal charges must be laid, these incidents transcend “bullying,” a term that has little legal meaning for police officers.  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