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   69138篇
  免费   3281篇
各国政治   4497篇
工人农民   2869篇
世界政治   6020篇
外交国际关系   3849篇
法律   32713篇
中国共产党   9篇
中国政治   766篇
政治理论   20752篇
综合类   944篇
  2021年   406篇
  2020年   1157篇
  2019年   1522篇
  2018年   1656篇
  2017年   1980篇
  2016年   2157篇
  2015年   1827篇
  2014年   2091篇
  2013年   10575篇
  2012年   1590篇
  2011年   1730篇
  2010年   1819篇
  2009年   2063篇
  2008年   1752篇
  2007年   1737篇
  2006年   1908篇
  2005年   1793篇
  2004年   1677篇
  2003年   1493篇
  2002年   1542篇
  2001年   1587篇
  2000年   1385篇
  1999年   1247篇
  1998年   1116篇
  1997年   982篇
  1996年   961篇
  1995年   941篇
  1994年   936篇
  1993年   956篇
  1992年   993篇
  1991年   1029篇
  1990年   980篇
  1989年   1024篇
  1988年   996篇
  1987年   1026篇
  1986年   1026篇
  1985年   1104篇
  1984年   978篇
  1983年   1027篇
  1982年   900篇
  1981年   848篇
  1980年   668篇
  1979年   707篇
  1978年   585篇
  1977年   547篇
  1976年   493篇
  1975年   413篇
  1974年   432篇
  1973年   427篇
  1972年   374篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
741.
742.
743.
Quadratic pieces of fleece measuring 16 mm2 were soaked with 10 different blood-samples in the dilution steps of 1:1, 1:10, 1:100, 1:1000, respectively, and were tested in blood group typing and identification tests of forensic serology. The above spezified dilutions correspond with 5 microliters, 0.5 microliter, 0.05 microliter and 0.005 microliter of blood, respectively. The detection limit of the microspectrometric test for blood was the dilution 1:10, of the porphyrine test a dilution above 1:100, whereas the preliminary test for blood (peroxidase) succeeded always up to a dilution of 1:1000 and the species determination by the radial immunodiffusion test in agar gels succeeded in most cases op to a dilution of 1:1000. The detection limit of the anti-human globulin inhibition test was between the dilution steps 1:10 and 1:100 when non-titrated and undiluted anti-human globulin serum was used. Gc- and ABO-grouping were possible up to a dilution of 1:100 and were thus the most sensitive grouping systems. Phenotyping of the enzyme-systems and the Gm/Km-system usually required stains with considerably higher blood concentrations i.e. stains of undiluted blood.  相似文献   
744.
745.
One of the remedies sought by state and local officials for the growing burden of federal mandates is a mandate reimbursement law. A major purpose of mandate reimbursement is to deter Congress from imposing excessive costs on state and local governments by making it fully accountable for its actions. The paper begins by extending the economic theory of grants to mandates and reimbursed mandates. It goes on to assess the benefits and costs of mandate reimbursement, and to distinguish mandates that should be reimbursed, should a reimbursement program prove desirable, from those that should not. Then, using the economic theory of grants and mandates, the paper compares reimbursed mandates with two alternatives for accomplishing the same objective, compensating grants and procedural rules. It concludes that the latter are more promising than mandate reimbursement.  相似文献   
746.
747.
748.
749.
750.
In 1990, the state of California passed the pioneering mandate on zero emission vehicles (ZEV). This technology‐forcing regulation is aimed at improvement of air quality and protection of public health from the adverse effects of air pollutants from automobiles. Facing severe opposition from the auto industry, the mandate has been revised a number of times, most recently in 2003, whereby the requirement for ZEVs have been made to align with the pace of technology development. Review of strategies used in implementation of the mandate has revealed greater emphasis on the economic incentives for rather than on environmental merits of ZEVs. Using prospect theory as the framework for analysis, the reasons have been explored. The findings of the study help us to understand how decisions are made with respect with to deviations from a mental anchor point and through the process of evaluation of losses and gains.  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