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   12986篇
  免费   414篇
各国政治   594篇
工人农民   479篇
世界政治   970篇
外交国际关系   473篇
法律   7791篇
中国政治   89篇
政治理论   2894篇
综合类   110篇
  2020年   153篇
  2019年   226篇
  2018年   275篇
  2017年   326篇
  2016年   344篇
  2015年   240篇
  2014年   280篇
  2013年   1349篇
  2012年   301篇
  2011年   330篇
  2010年   278篇
  2009年   344篇
  2008年   352篇
  2007年   372篇
  2006年   356篇
  2005年   327篇
  2004年   310篇
  2003年   316篇
  2002年   319篇
  2001年   478篇
  2000年   422篇
  1999年   334篇
  1998年   207篇
  1997年   152篇
  1996年   171篇
  1995年   163篇
  1994年   156篇
  1993年   150篇
  1992年   257篇
  1991年   263篇
  1990年   265篇
  1989年   261篇
  1988年   251篇
  1987年   242篇
  1986年   267篇
  1985年   259篇
  1984年   240篇
  1983年   223篇
  1982年   158篇
  1981年   135篇
  1980年   117篇
  1979年   160篇
  1978年   89篇
  1977年   118篇
  1976年   96篇
  1975年   75篇
  1974年   92篇
  1973年   90篇
  1972年   83篇
  1971年   78篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
A gas chromatographic (GC) fingerprint method, based on the presence or absence of six congeners, was developed for illicit cocaine samples. The fingerprint utilizes the relative abundances of these congeners towards each other, disregarding cocaine as the main constituent, and can be expressed numerically or graphically in the form of pictograms for rapid visual comparison. The method can be applied directly to a solution of the sample in chloroform, without previous workup procedures. More than 70 unrelated samples were analyzed and a great variation was observed in the parameter composition. On the other hand, a remarkable similarity could be seen between related samples. The GC fingerprint method may be considered an important contribution for sample comparison, as is exemplified by a subdivision of the analyzed samples in different categories, based on the number and types of congeners found.  相似文献   
62.
The polymerase chain reaction (PCR) method of specific gene amplification was used in casework to synthesize millions of copies of the polymorphic second exon of the human leukocyte antigen (HLA)-DQ alpha (or DQA1) locus from a variety of evidence samples. The HLA-DQ alpha allelic variants in the amplified deoxyribonucleic acid (DNA) were determined in a rapid non-radioactive test by hybridization to sequence-specific oligonucleotide probes in both the dot-blot and reverse dot-blot formats. This genetic typing system has been subjected to blind proficiency testing; the performance of this test in the analysis of experimentally mixed samples was also evaluated. As of August 1990, over 250 cases have been tested and more than 2000 individual evidence (bloodstains, semen stains, individual hairs, bone fragments, and tissue sections) and reference samples have been analyzed. The first 198 of these cases are summarized in this paper; in 65% of the cases with conclusive results a suspect was included, and in 35%, all suspects were excluded. Individual cases as well as some of the general issues relating to forensic science analysis and this genetic typing system are discussed. The high rate of exclusion reported here combined with the ability of PCR to type old evidence samples suggests the relevance of this genetic test for postconviction review; two cases in which the convicted suspect was excluded are discussed.  相似文献   
63.
An improved method has been developed for the reliable classification of different C1R genetic variant forms from human serum or plasma. The method combines the use of neuraminidase-digested samples followed by monodimensional isoelectric focusing in the pH range 5 to 8 followed by immunoblotting. The method yields a simple pattern, with one major band in homozygote and two major bands in heterozygote cases.  相似文献   
64.
Fabella  R. V. 《Public Choice》1996,89(3-4):325-337
Public Choice - We consider an economy where the rent value depends indirectly on value-adding investment of agents (thus indirectly endogenous) and the win-probability is a function of rent...  相似文献   
65.
China's experiments with democracy in this century were few in number, short in duration, and limited in their democratic characteristics. Democratic institutions malfunctioned in numerous ways. Nine sets of causes for the failure of Chinese democracy can be suggested: ideology, internal and external war, military intervention, Chinese political culture, underdevelopment, a peasant mass, flaws in the design of Chinese constitutions, moral failures by democratic politicians, or the lack of transactional benefits for military‐based elites in the process of democratic transition. Each of these factors is reviewed critically with an eye to its possible lessons.  相似文献   
66.
67.
68.
69.
We develop a model of the peace dividend and use it to predict the fiscal consequences of a reduction in the demand for military spending. The model is based on the assumption that the political process responds to political demands and costs in a way that maximizes net political benefits. The predictions of our model on how a peace dividend will be allocated over nonmilitary spending, tax relief, and deficit reduction is tested against the experience of eight major wars in United States history.  相似文献   
70.
A method ist described to determine the CO-content in the tissue of muscles. The prepared tissue is pulverized in a swinging mill at the temperature of liquid nitrogen. Parts of the powder are weighed into headspace vessels. Carbon monoxide ist ejected by a formerly described method and measured gaschromatographically. The Fe-content is determined after an acid disintegration by AAS. Acute intoxications lead to higher CO-contents in heart than in periphere muscles. Chronic exposure to carbon monoxide does not produce these differences.  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