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   18927篇
  免费   653篇
  国内免费   5篇
各国政治   879篇
工人农民   797篇
世界政治   1355篇
外交国际关系   722篇
法律   11540篇
中国共产党   6篇
中国政治   165篇
政治理论   3886篇
综合类   235篇
  2021年   107篇
  2020年   264篇
  2019年   319篇
  2018年   423篇
  2017年   464篇
  2016年   488篇
  2015年   345篇
  2014年   364篇
  2013年   1895篇
  2012年   526篇
  2011年   562篇
  2010年   458篇
  2009年   488篇
  2008年   577篇
  2007年   641篇
  2006年   584篇
  2005年   562篇
  2004年   541篇
  2003年   554篇
  2002年   493篇
  2001年   733篇
  2000年   611篇
  1999年   527篇
  1998年   289篇
  1997年   211篇
  1996年   248篇
  1995年   214篇
  1994年   234篇
  1993年   225篇
  1992年   363篇
  1991年   397篇
  1990年   377篇
  1989年   320篇
  1988年   346篇
  1987年   287篇
  1986年   339篇
  1985年   302篇
  1984年   253篇
  1983年   237篇
  1982年   201篇
  1981年   225篇
  1980年   153篇
  1979年   182篇
  1978年   135篇
  1977年   116篇
  1976年   102篇
  1975年   133篇
  1974年   143篇
  1973年   110篇
  1972年   104篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
We investigated the differences in the levels of carboxyhemoglobin (COHb), cyanide (HCN) and petroleum fuels (gasoline and kerosene) between left and right ventricular bloods from fire victims. COHb was slightly, and HCN and petroleum fuels were markedly higher levels in the left than those in the right. These effects were so called 'first pass phenomena' due to the circulation, diffusion and metabolization before the deaths of fire victims.  相似文献   
72.
73.
To account for variance in great powers responses to threats and the implications for the peacefulness of the international system since the late nineteenth century, this article elucidates a theory which refines and synthesizes economic liberal perspectives and realist balance of power theory. I argue that different patterns and levels of economic interdependence in the great power system generate societal-based economic constraints on, or incentives for, state leaders of status quo powers hoping to mobilize economic resources and political support to oppose perceived threats. This mobilization process influences strongly the preferences of status quo powers, other states beliefs about those preferences, and the interpretation of signals in balance of power politics. In this way, economic ties influence the strategies great powers pursue. Firm balancing policies conducive to peace in the international system are most likely, I then hypothesize, when there are extensive economic ties among status quo powers and few or no such links between them and perceived threatening powers. When economic interdependence is not significant between status quo powers or if status quo powers have strong economic links with threatening powers, weaker balancing postures and conciliatory policies by status quo powers, and aggression by aspiring revisionist powers, are more likely. I then illustrate how these hypotheses explain the development of the Franco-Russian alliance of the 1890s and its effectiveness as a deterrent of Germany up to 1905, British ambivalence toward Germany from 1906 to the First World War, the weakness of British, French, Soviet, and American behavior toward Germany in the 1930s and World War II, and the American and European responses to the Soviet threat, including the NATO alliance, and the "long peace" of the post-1945 era.  相似文献   
74.
75.
Good gas chromatography (GC) separation of molecules is essential for clean gas chromatography/mass spectrometry (GC/MS) confirmation of compounds. The trifluoro derivatives of ephedrine (E) and methamphetamine (MA) coelute on dimethyl silicone capillary columns, such as DB-1, which are most commonly used by chromatographers. Methods are described to separate E and MA to aid GC/MS confirmations of methamphetamine, ephedrine, or both E and MA together, whichever may be present in Enzyme Immunoassay (EIA)-analyzed amphetamine-positive urine samples. The use of the heptafluoro derivatives of E and MA on a DB-1 column, or the trifluoro derivatives of E and MA on a DB-17 column, is suggested for good gas chromatographic separation.  相似文献   
76.
One case of the erroneous administration of deslanoside and high level of drug in antemortem plasma and postmortem specimens has been reported owing to the unusual surrounding circumstances. Deslanoside in antemortem plasma was determined by FPIA and the analysis was done by HPLC in the postmortem tissue samples. The analytical results and methods used in the examinations are discussed in the following paper.  相似文献   
77.
78.
The enzyme activity of phosphoglucomutase (PGM) has been investigated in red cell haemolysates from 142 individuals and compared to the sub-type as determined by isoelectric focusing. The 10 phenotypes showed significant differences in PGM-activity which indicates that there is a correlation between the level of activity and the isolelectric point of homozygotes. No indication of silent alleles or alleles with reduced activity was found in this collective.  相似文献   
79.
The Tax Reform Act of 1986 rewrote the federal income tax code, bringing it closer to policy professionals' vision of what constitutes an equitable and efficient income tax. Research on tax compliance suggests the law might have affected taxpayer compliance in three ways: by reducing opportunities to overstate deductions, by changing perceptions of fairness, and by altering tax liabilities. Changes in taxpayer perceptions, attitudes, and noncompliance intentions were examined in three bodies of survey data, each containing pre-and post-reform data from independent samples of the same population. The results show an improved normative climate for taxpayer compliance and point to both the feasibility and the importance of examining the effects of substantive tax policies on taxpayer perceptions, attitudes, and behavioral intentions.  相似文献   
80.
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