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   1830篇
  免费   518篇
各国政治   410篇
工人农民   64篇
世界政治   241篇
外交国际关系   102篇
法律   776篇
中国政治   36篇
政治理论   682篇
综合类   37篇
  2024年   1篇
  2023年   1篇
  2022年   3篇
  2021年   33篇
  2020年   44篇
  2019年   165篇
  2018年   99篇
  2017年   151篇
  2016年   158篇
  2015年   141篇
  2014年   131篇
  2013年   575篇
  2012年   94篇
  2011年   104篇
  2010年   112篇
  2009年   52篇
  2008年   69篇
  2007年   41篇
  2006年   42篇
  2005年   27篇
  2004年   35篇
  2003年   22篇
  2002年   23篇
  2001年   9篇
  2000年   19篇
  1999年   15篇
  1998年   13篇
  1997年   14篇
  1996年   17篇
  1995年   13篇
  1994年   12篇
  1993年   13篇
  1992年   9篇
  1991年   5篇
  1990年   10篇
  1989年   5篇
  1988年   9篇
  1987年   5篇
  1986年   6篇
  1985年   5篇
  1984年   8篇
  1983年   6篇
  1982年   2篇
  1981年   7篇
  1980年   6篇
  1979年   4篇
  1978年   5篇
  1977年   4篇
  1976年   1篇
  1974年   3篇
排序方式: 共有2348条查询结果,搜索用时 15 毫秒
251.
The case of a 22‐year‐old male Caucasian driver is presented. He was involved in a traffic collision. At the roadside, he displayed blank stare and mellow speech with a barely audible voice. A DRE found low body temperature, rigid muscle tone, normal pulse, lack of horizontal and vertical gaze nystagmus, nonconvergence of the eyes, dilated pupil size, and normal Pupillary reaction to light. A standard toxicology DUID protocol was performed on the driver's whole blood including ELISA and GC‐MS drug screens with negative results. Additional drug screening was undertaken for bath salts and synthetic cannabinoid receptor agonists by LC‐MS/MS by a commercial laboratory and identified the synthetic cannabinoid receptor agonist XLR‐11 in the driver's blood. XLR‐11 was subsequently quantified at 1.34 ng/mL. This is the first documented case involving a driver operating a motor vehicle under the influence of the synthetic cannabinoid receptor agonist XLR‐11.  相似文献   
252.
Public Law 280 transferred jurisdiction over criminal and civil matters from the federal to state governments and increased the extent of nontribal law enforcement in selected parts of Indian country. Where enacted, the law fundamentally altered the preexisting legal order. Public Law 280 thus provides a unique opportunity to study the impact of legal institutions and their change on socioeconomic outcomes. The law's controversial content has attracted interest from legal scholars. However, empirical studies of its impact are scarce and do not address the law's endogenous nature. We examine the law's impact on crime and on economic development in U.S. counties with significant American‐Indian reservation population. To address the issue of selection of areas subject to Public Law 280, our empirical strategy draws on the law's politico‐historical context. We find that the application of Public Law 280 increased crime and lowered incomes. The law's adverse impact is robust and noteworthy in magnitude.  相似文献   
253.
Gas chromatography–mass spectrometry (GC–MS) data of ignitable liquids in the Ignitable Liquids Reference Collection (ILRC) database were processed to obtain 445 total ion spectra (TIS), that is, average mass spectra across the chromatographic profile. Hierarchical cluster analysis, an unsupervised learning technique, was applied to find features useful for classification of ignitable liquids. A combination of the correlation distance and average linkage was utilized for grouping ignitable liquids with similar chemical composition. This study evaluated whether hierarchical cluster analysis of the TIS would cluster together ignitable liquids of the same ASTM class assignment, as designated in the ILRC database. The ignitable liquids clustered based on their chemical composition, and the ignitable liquids within each cluster were predominantly from one ASTM E1618‐11 class. These results reinforce use of the TIS as a tool to aid in forensic fire debris analysis.  相似文献   
254.
255.
In many criminal and civil cases in China, the most commonly questioned documents are those written with gel pen ink. An important task for forensic document examiners is to identify whether two or more ink entries in one or more documents were written with the same ink type. The identification of the age of gel ink entries made poses an important and difficult problem for forensic document examiners. In this paper, the volatile components of gel ink were determined and the gel ink was classified by gas chromatography with a flame ionization detector. Calibration curves were created to express the relationship between the content of volatile gel ink components and the age of gel ink entries stored under natural and UV‐induced aging conditions. The correspondence between the natural and UV‐induced aging conditions was also established. The experimental results showed that GC was useful in the analysis of black gel ink and applicable for determining the relative age of gel ink entries under certain conditions.  相似文献   
256.
257.
In this study, the Raman spectra of 21 phenethylamines were obtained using far‐red excitation (785 nm). The distinguishing ability of Raman for phenethylamines, especially for phenethylamine regioisomers and structural analogues, was investigated. Here, the evaluation of a cross section of Raman spectra demonstrated that all types of phenethylamines were distinguishable, even for certain structural analogues with high spectrum similarity. Raman exhibited high distinguishing ability for phenethylamine regioisomers that differ in the substitution position of halogen, methoxy, alkyl, or other substituted groups; as well as for structural analogues containing different groups, such as furanyl, 2,3‐dihydrofuranyl, halogen, and alkyl substituted at the same position. The Raman spectra for homologues with differences in only a methyl group were found to be highly similar; however, their spectra demonstrated small but detectable differences. Four analogue mixtures and 59 seized samples were also analyzed to study the practical use of the Raman method in forensic field. 95% of the seized samples were correctly identified, which significantly validated the ability of Raman method in identifying the correct isomers. Accordingly, this study provides a non‐destructive, high‐throughput and minimal sample preparation technique for the discrimination of phenethylamines.  相似文献   
258.
In this article we present the schools of thought comprising Critical Management Studies (CMS), explore their implications for public administration, and provide an alternate definition of democratic governance. We synthesize and describe the “modern stream,” inspired by the Frankfurt School, and the “postmodern stream,” associated with poststructuralist authors. Despite significant epistemological and ontological differences, these perspectives complement each other and cast new light on democratic governance. We present the respective theories of Foucault and Habermas, explore their implications for public administration, reconcile their views on power as a basis for a normative definition for so‐called good governance, and redefine the concept of “democratic governance.”  相似文献   
259.
260.
Refugee and labour immigration have placed the issue of immigrants’ access to welfare benefits high on the political agenda. This article explores how voter preferences for increases in the child benefit change when respondents are reminded about immigrants’ access to benefits. The survey experiment shows that information about newly arrived immigrants’ access to child benefit has only a small impact on support for increasing the child allowance. By contrast, information about labour migrants’ access to benefits for children living in another European Union country has a strong impact, and the observed sensitivity to this cue is not to the same extent confined to respondents who otherwise support welfare dualism.  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