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   18657篇
  免费   585篇
各国政治   853篇
工人农民   703篇
世界政治   1587篇
外交国际关系   725篇
法律   10889篇
中国共产党   2篇
中国政治   94篇
政治理论   4194篇
综合类   195篇
  2021年   98篇
  2020年   236篇
  2019年   302篇
  2018年   374篇
  2017年   449篇
  2016年   492篇
  2015年   335篇
  2014年   392篇
  2013年   1954篇
  2012年   453篇
  2011年   469篇
  2010年   390篇
  2009年   432篇
  2008年   502篇
  2007年   528篇
  2006年   511篇
  2005年   453篇
  2004年   435篇
  2003年   479篇
  2002年   437篇
  2001年   707篇
  2000年   659篇
  1999年   537篇
  1998年   328篇
  1997年   269篇
  1996年   234篇
  1995年   232篇
  1994年   265篇
  1993年   229篇
  1992年   355篇
  1991年   373篇
  1990年   344篇
  1989年   348篇
  1988年   336篇
  1987年   346篇
  1986年   341篇
  1985年   332篇
  1984年   291篇
  1983年   322篇
  1982年   261篇
  1981年   243篇
  1980年   182篇
  1979年   255篇
  1978年   168篇
  1977年   151篇
  1976年   131篇
  1975年   123篇
  1974年   136篇
  1973年   117篇
  1972年   112篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
With the rapid growth of cross-border competition among currencies, informed observers predict that the new monetary unions are virtually inevitable in many parts of the world. In fact, predictions of such alliances are misleading and almost certainly wrong. Monetary unions necessarily imply a measure of collective action in the issue and management of money. An alliance requires allies—other states with similar preferences and a disposition to act cooperatively. A survey of proposed monetary unions shows that willing partners among sovereign states are just not all that plentiful. Conceivably some governments could be attracted to less demanding forms of monetary alliance, depending on bargaining context. But prospects for many full new monetary unions are dim at best.  相似文献   
132.
Bioaerosol data is often used in cases of building mold infestation alleging damage or adverse health effects upon occupants, despite the lack of consistent sampling and analytical protocols and numerical health-based standards. The most fundamental problem in these scenarios is defining a “significant” difference between a suspect indoor environment and the reference environment, regardless of the type of sampling and analysis utilized. Data interpretation focused upon differences in absolute numerical concentrations of fungi is subject to wide differences in expert opinion. On the other hand, an objective quantification of differences can be expressed in terms of probability and better meets criteria established in evidentiary rules.  相似文献   
133.
The 2003 Duma election resulted in the victory of the party of power, thereby strengthening managed democracy in Russia. Since then, political trends in Russia's regions and rural politics provide considerable evidence of the increasing ability of pro-Kremlin forces to maximise their electoral fortunes in national contests. These political trends make it likely that United Russia will not only emerge as the dominant party in the 2007 Duma election, but will provide the Kremlin and Putin's successor with a compliant lower house. The outcome is that Putin's successor will find the political infrastructure to continue managed democracy.  相似文献   
134.
135.
136.
137.
A 6-month-old girl died suddenly without any previous symptoms of heart failure. Autopsy examination showed cardiomegaly (97 g) with a severely fibrotized myocardium. The left coronary artery was originating from the pulmonary artery. Histologically, the myocardium showed myocardial infarcts of different ages, as well as grossly thickened arterial branches due to increased flow in left-right shunt. We suggest that rare anomalies of the coronary arteries should be considered in the autopsies of suspected sudden infant death syndrome cases.  相似文献   
138.
The impact of high temperatures (24 to 39 degrees C) and low to moderately high humidities (20 to 70%) on the applicability of TLC systems for drug identification was studied during a 6 month climatologic cycle in Burkina Faso (West Africa). In general, the Rf values as observed on the plates were found to be substantially affected as compared with values obtained at temperate climates. Some TLC systems were more affected than others and the largest deviations of up to 30 Rf units were at low humidities. Tropical conditions also had a negative effect on the reproducibility of Rf values. However, when an Rf-correction procedure was applied, using reference mixtures of known drugs on each plate, accuracy as well as reproducibility of the resulting Rfc values were drastically improved and data thus corrected were found to be compatible with existing TLC data bases developed under moderate climatological conditions. The impact of high to extremely high humidities (70 to 100%) remains to be investigated.  相似文献   
139.
Washington University v. Catalona revolves around ownership of tissue samples provided by patients for research purposes, raising significant ethical and legal questions concerning patient rights, current human research practices, and the treatment of samples as capital resources by the research institution.  相似文献   
140.
In this study, a new method was developed for the impurity profiling of illicit MDMA tablets. The extraction efficiency, linearity, repeatability and reproducibility of the method were evaluated. Eighty two MDMA tablets coming from presumed unrelated large seizures in 2004 (n >500 tablets) were analyzed by gas chromatography mass spectrometry (GC-MS) in order to assess the discrimination power of the method. The latter was found to be practical, robust, relatively easy to perform, highly discriminative and yielding good chromatography. In addition, some new impurities were detected and identified. Their chemical structures and mass spectra are reported.  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