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   16965篇
  免费   454篇
各国政治   807篇
工人农民   661篇
世界政治   1116篇
外交国际关系   543篇
法律   10540篇
中国政治   103篇
政治理论   3513篇
综合类   136篇
  2020年   170篇
  2019年   233篇
  2018年   297篇
  2017年   347篇
  2016年   351篇
  2015年   261篇
  2014年   308篇
  2013年   1651篇
  2012年   349篇
  2011年   404篇
  2010年   345篇
  2009年   391篇
  2008年   419篇
  2007年   439篇
  2006年   432篇
  2005年   384篇
  2004年   363篇
  2003年   393篇
  2002年   358篇
  2001年   657篇
  2000年   567篇
  1999年   483篇
  1998年   247篇
  1997年   198篇
  1996年   200篇
  1995年   192篇
  1994年   202篇
  1993年   197篇
  1992年   334篇
  1991年   382篇
  1990年   367篇
  1989年   372篇
  1988年   360篇
  1987年   366篇
  1986年   402篇
  1985年   387篇
  1984年   345篇
  1983年   321篇
  1982年   219篇
  1981年   211篇
  1980年   176篇
  1979年   262篇
  1978年   169篇
  1977年   174篇
  1976年   146篇
  1975年   145篇
  1974年   170篇
  1973年   159篇
  1972年   128篇
  1971年   116篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
151.
152.
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   
153.
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   
154.
155.
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   
156.
This article surveys the voluminous economic literature on commoditybundling. While bundling has been widely studied, the vast majorityof the literature has focused on theoretical treatments of bundlingthat demonstrate a wide range of reasons why firms might engagein bundling. These papers generally contain restrictive assumptions,including assumptions regarding the existence of monopoly insome markets, and the nature of rivalry in others. The modelscontained in these papers also generally suppress the more obviousand ubiquitous reasons firms may use bundling. Moreover, thesemodels have not been subject to robustness checks, nor havetheir assumptions been tested empirically. This review of theeconomic literature generally confirms the US Solicitor General'sview in 3M v. LePage's regarding the underdeveloped state ofthe economics literature and its position that the US SupremeCourt should defer promulgation of antitrust standards for bundling.While the literature has demonstrated the possibility that bundlingcan generate anticompetitive harm, it does not provide a reliableway to gauge whether the potential for harm would outweigh anydemonstrable benefits from the practice. As a result, the widespreadapplication of the antitrust laws to bundling by firms can generatesignificant error costs by erroneously condemning or deterringefficient business practices. In the future, economists shouldseek to expand their understanding of both the anticompetitiveand procompetitive reasons firms engage in bundling. This willentail studying the reasons why bundling is adopted by firmswithout market power, relaxing the assumption of monopoly intheoretical models, and generating testable hypotheses and thedata to test them.  相似文献   
157.
158.
159.
160.
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