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   11477篇
  免费   343篇
各国政治   478篇
工人农民   411篇
世界政治   786篇
外交国际关系   381篇
法律   7055篇
中国政治   73篇
政治理论   2541篇
综合类   95篇
  2020年   133篇
  2019年   189篇
  2018年   226篇
  2017年   262篇
  2016年   253篇
  2015年   203篇
  2014年   214篇
  2013年   1116篇
  2012年   241篇
  2011年   304篇
  2010年   229篇
  2009年   299篇
  2008年   296篇
  2007年   305篇
  2006年   295篇
  2005年   267篇
  2004年   257篇
  2003年   269篇
  2002年   269篇
  2001年   437篇
  2000年   383篇
  1999年   310篇
  1998年   174篇
  1997年   136篇
  1996年   147篇
  1995年   136篇
  1994年   148篇
  1993年   142篇
  1992年   240篇
  1991年   257篇
  1990年   249篇
  1989年   253篇
  1988年   228篇
  1987年   226篇
  1986年   267篇
  1985年   260篇
  1984年   231篇
  1983年   218篇
  1982年   153篇
  1981年   129篇
  1980年   116篇
  1979年   152篇
  1978年   87篇
  1977年   113篇
  1976年   98篇
  1975年   72篇
  1974年   90篇
  1973年   84篇
  1972年   78篇
  1971年   69篇
排序方式: 共有10000条查询结果,搜索用时 593 毫秒
851.
852.
A method was developed to screen for pepper spray residue using instruments and methods other than those techniques commonly employed to analyze chemical residue (i.e.. gas chromatography mass spectrometry-GCMS or liquid chromatography mass spectrometry-LCMS). The method employed gas chromatography (GC), thin layer chromatography (TLC), and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) to screen for dried pepper spray stains. Pepper sprays from nine different manufacturers were investigated. Capsaicin and dihydrocapsaicin were identified and unique IR reflectance spectra are presented. An additional five compounds were presumptively found. Results showed that a particular stain could be characterized as a pepper-based stain.  相似文献   
853.
Supraphysiologic doses of testosterone are associated with increased aggression that is hypothesized to be a function of testosterone serum concentrations, mood, and personality. The study attempted to characterize this relationship among weightlifters who were users (n = 10) and nonusers (n = 18) of anabolic steroids. Participants were interviewed using the Modified Mania Rating Scale and Hamilton Rating Scale for Depression to assess mood, the Buss-Durkee Hostility Inventory (BDHI) and Point Subtraction Aggression Paradigm (PSAP) to assess aggression, and the Personality Disorder Questionnaire (PDQ-R) to assess personality. Blood samples were obtained for the determination of total, free, and weakly bound testosterone. Comparisons of continuous variables between testosterone users and non-users were performed with a parametric (unpaired t-test) or non-parametric (Mann-Whitney) test where appropriate. Correlations with testosterone were examined separately for testosterone users and non-users, using Spearman rank correlation. The subjective (BDHI) and objective (PSAP) assessments of aggression found that supranormal testosterone concentrations were associated with increased aggression. However, the PDQ-R results suggest that this finding was confounded by the personality disorder profile of the steroid users, because steroid users demonstrated Cluster B personality disorder traits for antisocial, borderline, and histrionic personality disorder.  相似文献   
854.
The presence of cocaine in illicit drug samples is still being determined in some laboratories using spot tests and microcrystal tests. Seventeen chemical species were tested using three different spot tests (Wagner, Marquis, and cobalt thiocyanate followed by stannous chloride reactions) and two microcrystal tests (gold chloride and platinic chloride) to determine whether the results could be differentiated from the results of these tests on cocaine. The data obtained indicated that nine of the 17 compounds gave results similar to those from cocaine using the three spot tests, but that the results from microcrystal testing allowed for differentiation of all nine compounds from cocaine.  相似文献   
855.
856.
857.

Introduction

Introduction to special issue on professional insecurities  相似文献   
858.

Commentary

Commentaries on Brunner and Willards professional insecurities  相似文献   
859.
860.
Subject Acquisition for Web-Based Surveys   总被引:1,自引:0,他引:1  
  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