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   20945篇
  免费   641篇
各国政治   920篇
工人农民   816篇
世界政治   1716篇
外交国际关系   697篇
法律   12573篇
中国共产党   3篇
中国政治   102篇
政治理论   4557篇
综合类   202篇
  2020年   260篇
  2019年   307篇
  2018年   398篇
  2017年   476篇
  2016年   498篇
  2015年   370篇
  2014年   411篇
  2013年   2102篇
  2012年   514篇
  2011年   523篇
  2010年   429篇
  2009年   461篇
  2008年   550篇
  2007年   569篇
  2006年   548篇
  2005年   491篇
  2004年   496篇
  2003年   511篇
  2002年   471篇
  2001年   792篇
  2000年   739篇
  1999年   602篇
  1998年   342篇
  1997年   287篇
  1996年   238篇
  1995年   251篇
  1994年   286篇
  1993年   259篇
  1992年   413篇
  1991年   436篇
  1990年   410篇
  1989年   417篇
  1988年   384篇
  1987年   403篇
  1986年   418篇
  1985年   424篇
  1984年   352篇
  1983年   382篇
  1982年   301篇
  1981年   276篇
  1980年   220篇
  1979年   288篇
  1978年   205篇
  1977年   170篇
  1976年   161篇
  1975年   155篇
  1974年   185篇
  1973年   166篇
  1972年   145篇
  1970年   121篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
171.
Large-scale privatization is an unfamiliar area of public policy. The practice and study of property reforms and privatization needs to include mesolvel phenomena such as laws, regulations, institutions and standard operating procedures. There has been little comparative analysis of privatization programs around the world. The author argues that analysts should compare the most immediately relevant institutional environment of the enterprise. Conceptually, this mesolevel system is situated between the firm and the macroeconomy. This system of action is especially fruitful for cross-national comparisons of privatization programs because it is at this level that privatization strategies are designed. The problem for Eastern Europe and for less-developed countries is lack of experience with the relatively light economic regulation that characterizes industrial countries. Government leaders must also decide how much effort to devote to privatization of state-owned enterprises and how much to fostering private sector investment in new firms. Ernest J. Wilson, III is affiliated with the National Security Council, Washington, D.C.  相似文献   
172.
Although past research has developed scales for the incidence, prevalence, and fear of student-on-student victimization (SSV), little is known about the scaling of perceived risk (i.e., the cognitive appraisal of the chances of experiencing SSV). Hence, this study examined self-report survey data for the perceived risk of SSV as measured in the Adolescent Index for School Safety (AISS). Children in grades 7 through 10 (n=337) in a single Florida public school completed the AISS. Factor analyses using Maximum Likelihood Estimation with Oblimin Rotation identified nine unique factors for perceived risk. Reliability analyses found standardized Cronbach Alphas that ranged from .64 to .91, and seven out of the nine identified scales were above .80, which suggested good to excellent internal consistency. Future research should examine the content validity, construct validity, and predictive validity for the AISS and other self-report surveys of SSV dynamics. This publication was made possible by a grant [#97-MU-FX-KO12 (S-l)] from the Office of Juvenile Justice and Delinquency Prevention (O.J.J.D.P.), United States Department of Justice (U.S.D.O.J.). This grant is administered through the Hamilton Fish National Institute on School and Community Violence at George Washington University. This specific study was developed and implemented by staff at: 1) East Carolina University’s Department of Criminal Justice; and 2) Florida State University’s Center for Educational Research and Policy Studies. All points of view and opinions in this paper are those of the authors and do not necessarily represent the official position or policies of East Carolina University, Florida State University, the Hamilton Fish National Institute on School and Community Violence, the O.J.J.D.P., or the U.S.D.OJ. The authors would also like to thank Dr. Bill Doerner and Jennifer Jolley for their support, editorial feedback, and insightful comments regarding earlier drafts of this paper.  相似文献   
173.
174.
The purpose of this survey was to determine the methods of analysis being used on gunshot residue (GSR) samples in forensic science laboratories across the United States. In addition, the two general techniques of GSR analysis are compared and contrasted. Problems encountered by analysts using scanning electron microscopy/energy-dispersive X-ray analysis (SEM/EDX) are discussed.  相似文献   
175.
Quadratic pieces of fleece measuring 16 mm2 were soaked with 10 different blood-samples in the dilution steps of 1:1, 1:10, 1:100, 1:1000, respectively, and were tested in blood group typing and identification tests of forensic serology. The above spezified dilutions correspond with 5 microliters, 0.5 microliter, 0.05 microliter and 0.005 microliter of blood, respectively. The detection limit of the microspectrometric test for blood was the dilution 1:10, of the porphyrine test a dilution above 1:100, whereas the preliminary test for blood (peroxidase) succeeded always up to a dilution of 1:1000 and the species determination by the radial immunodiffusion test in agar gels succeeded in most cases op to a dilution of 1:1000. The detection limit of the anti-human globulin inhibition test was between the dilution steps 1:10 and 1:100 when non-titrated and undiluted anti-human globulin serum was used. Gc- and ABO-grouping were possible up to a dilution of 1:100 and were thus the most sensitive grouping systems. Phenotyping of the enzyme-systems and the Gm/Km-system usually required stains with considerably higher blood concentrations i.e. stains of undiluted blood.  相似文献   
176.
177.
178.
Modern antitrust policy has a ‘love hate’ relationshipwith non-standard contracts that can overcome market failure.On the one hand, courts have abandoned various per se rulesthat once condemned such agreements outright, concluding thatmany non-standard contracts may produce benefits that are cognizableunder the antitrust laws.1 The prospect of such benefits, itis said, compels courts to analyze these agreements under theRule of Reason, under which the tribunal determines whethera given restraint enhances or destroys competition.2 At thesame time, courts, scholars, and the enforcement agencies haveembraced methods of rule of reason analysis that are undulyhostile to such agreements.3 In particular, courts and othersare too quick to view such agreements and the market outcomesthey produce as manifestations of market power. This articleseeks to explain why these agreements are still the object ofundue hostility.  相似文献   
179.
Telecommunications regulation has experienced a fundamentalshift from rate regulation to increased reliance on compelledaccess, perhaps best exemplified by the Telecommunications Actof 1996's imposition of no fewer than four new access requirements.Unfortunately, each access requirement is governed by a separateset of rules for determining both the scope and the price ofaccess. The resulting ad hoc regime has created difficult definitionalproblems and opportunities for regulatory arbitrage. In thisarticle we propose a system inspired by the discipline of mathematicsknown as graph theory that integrates all of the different formsof access into a single analytical framework. This system separatesdifferent access regimes into five categories: (1) retail access,(2) wholesale access, (3) interconnection access, (4) platformaccess, and (5) unbundled access. It also provides insightsinto how each type of access complicates the already difficultproblems of network configuration and management and introducesinefficient biases into decisions about network capacity anddesign. The approach we propose also provides insights intothe transaction cost implications of the different types ofaccess. Drawing on the Coasean theory of the firm, our approachexamines the tradeoffs between internal governance costs andthe external transaction costs of providing access to offera theory of network boundaries. This framework shows how accessregulation distorts networks' natural boundaries and providesa basis for evaluating whether private ordering through marketswould lead to more efficient network design.  相似文献   
180.
Eighteen external quality assessment (proficiency testing) samples were prepared from client specimens collected with the Intercept® oral fluid collection device and by spiking drug-free oral fluid. Samples were circulated in pairs at quarterly intervals to 13 UK and USA based laboratories for analysis by a panel of OraSure micro-plate Intercept® enzyme immunoassay kits and hyphenated mass spectrophotometric techniques. During the survey, there was a single case of non-specificity in a false report for methadone. The major errors were of lack of sensitivity relative to the concentration thresholds specified for the immunoassays. The sensitivity for overall ‘present’/‘not found’ reports calculated as true positives/(true positives + false negatives) were for the amfetamine specific assay 50%, methyl-amfetamines 93%, barbiturates 64%, cannabinoids 73%, cocaine and metabolites 100%, benzodiazepines 69%, methadone 95%, opiates 79% (opiates excluding oxycodone 93%), phencyclidine 93% and human gamma-globulin 97%. A small number of the sensitivity errors were attributable to errors in chromatographic confirmation techniques.  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