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   5920篇
  免费   139篇
各国政治   249篇
工人农民   246篇
世界政治   478篇
外交国际关系   216篇
法律   3696篇
中国政治   53篇
政治理论   1103篇
综合类   18篇
  2021年   41篇
  2020年   76篇
  2019年   120篇
  2018年   146篇
  2017年   121篇
  2016年   123篇
  2015年   72篇
  2014年   128篇
  2013年   618篇
  2012年   147篇
  2011年   160篇
  2010年   125篇
  2009年   146篇
  2008年   178篇
  2007年   161篇
  2006年   145篇
  2005年   133篇
  2004年   157篇
  2003年   130篇
  2002年   112篇
  2001年   311篇
  2000年   280篇
  1999年   193篇
  1998年   79篇
  1997年   84篇
  1996年   53篇
  1995年   54篇
  1994年   48篇
  1993年   39篇
  1992年   126篇
  1991年   141篇
  1990年   133篇
  1989年   126篇
  1988年   114篇
  1987年   125篇
  1986年   101篇
  1985年   96篇
  1984年   96篇
  1983年   85篇
  1982年   59篇
  1981年   74篇
  1980年   34篇
  1979年   75篇
  1978年   44篇
  1975年   38篇
  1974年   49篇
  1973年   55篇
  1972年   39篇
  1971年   34篇
  1970年   29篇
排序方式: 共有6059条查询结果,搜索用时 15 毫秒
931.
Abstract

This article reports on timing the adverse effects of black carbon released into the atmosphere from biomass combustion, vehicular emissions and local combustion sources. Black carbon contributes to global warming through its light absorption capacity, has a direct and indirect impact on climate and public health, and will result in ongoing environmental damages and claims. The authors studied measurements of black carbon taken in Delhi, India during 2016 and 2017, and reports on seasonal factors that contribute to higher emissions.  相似文献   
932.
Police witness intelligence stated a murdered adult male “Fred” had been vertically buried in wooded hilly terrain 30 years ago in the Midlands, U.K. Conventional search methods were unsuccessful; therefore, the police requested a geophysical investigation to be undertaken to determine whether “Fred” could be detected. A multiphased geophysical approach was conducted, using bulk ground conductivity and metal detectors, then follow‐up magnetics and ground penetrating radar (GPR) survey profiles on electromagnetic (EM) anomalous areas. A tight grid pattern was used to account for the reduced target size. Relatively high‐resolution EM and GPR techniques were determined optimal for this terrain and sandy soil. Geophysical anomalies were identified and the most promising intrusively investigated, and this was found to be a large boulder and tree roots. Study implications suggest careful multiphase geophysical surveys are best practice and give confidence in cold case searches. This study yielded a no‐body result, effectively saving police time and costs from further investigations.  相似文献   
933.
934.
ABSTRACT

Recently, states have enacted teacher-carry laws. While controversial, little scholarship has tapped public attitudes toward such reforms. Because public opinion shapes policy, the public is an important stakeholder in this debate. Thus, we investigated three questions. First, how supportive is the public of arming teachers? Second, what demographic and social divides exist, if any, for reform approval? Finally, do crime-related perceptions, concerning views about public safety, and criminogenic influences shape policy preferences? We test these questions using a 2018 poll of Virginia residents (N = 521). Overall, approval for teacher-carry is split. Crime-related perceptions mediate some of the initial social and demographic divides in opinion but other correlates, such as parental status, remain salient predictors of views. Implications are discussed.  相似文献   
935.
936.
937.
938.
939.
Conventional models of bargaining and reassurance under incomplete information assume that actors' behavioral signals are objectively cooperative or noncooperative. Even if actors are uncertain of each other's preferences, they know what types of actions the other will view as cooperative. Yet on many real-world issues, cooperation is subjective, and what constitutes a cooperative action is conditional on the receiver's preferences. We present a formal model showing that in these cases, two-sided incomplete information actually incentivizes honest behavior and facilitates credible signaling. Because uncertain senders do not know whether a particular action will be interpreted as cooperative, they have little incentive to misrepresent, and instead honestly pursue their true goals. Thus, where cooperation is subjective, mutual uncertainty is “offsetting,” such that credible signals allow actors to quickly and accurately update their beliefs. We illustrate this logic through a case study of the Sino–Soviet split, and highlight the model's implications for contemporary U.S.–China relations.  相似文献   
940.
Kümper  Boas 《Natur und Recht》2022,44(5):305-317
Natur und Recht - Nachdem in NuR (2022, Heft 2, S. 77ff.) die Reichweite des wasserhaushaltsrechtlichen Planfeststellungsvorbehalts sowie Fragen der Verfahrenswahl erörtert wurden, behandeln...  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