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   5845篇
  免费   196篇
各国政治   463篇
工人农民   151篇
世界政治   628篇
外交国际关系   365篇
法律   2449篇
中国政治   34篇
政治理论   1877篇
综合类   74篇
  2023年   26篇
  2020年   74篇
  2019年   100篇
  2018年   132篇
  2017年   152篇
  2016年   164篇
  2015年   113篇
  2014年   151篇
  2013年   945篇
  2012年   150篇
  2011年   173篇
  2010年   145篇
  2009年   142篇
  2008年   191篇
  2007年   254篇
  2006年   190篇
  2005年   178篇
  2004年   194篇
  2003年   190篇
  2002年   183篇
  2001年   105篇
  2000年   114篇
  1999年   91篇
  1998年   124篇
  1997年   99篇
  1996年   107篇
  1995年   81篇
  1994年   73篇
  1993年   87篇
  1992年   73篇
  1991年   91篇
  1990年   77篇
  1989年   69篇
  1988年   76篇
  1987年   86篇
  1986年   85篇
  1985年   51篇
  1984年   70篇
  1983年   70篇
  1982年   66篇
  1981年   50篇
  1980年   47篇
  1979年   43篇
  1978年   44篇
  1977年   46篇
  1976年   26篇
  1975年   26篇
  1974年   27篇
  1973年   34篇
  1972年   23篇
排序方式: 共有6041条查询结果,搜索用时 31 毫秒
821.
This paper explores the clinical, social and demographic characteristics of 164 people on Community Treatment Orders (CTOs) in one area mental health service in Victoria, Australia. The results of an exploratory cluster analysis are presented to address the question of whether people on Community Treatment Orders can be categorised into statistically reliable, qualitatively distinct groupings. The data are presented in the context of key stakeholder perspectives on the current use and purpose of CTOs. Three stable clusters emerged and each potentially reflects how social dimensions, as well as clinical issues, influence decision making regarding the implementation of CTOs. These findings are important in the context of policy and practice in Victoria, where the use of CTOs is common practice, and orders are generally made for a 12 month period. The potential for improved targeting of CTOs and more specific treatment planning is identified.  相似文献   
822.
A method is suggested that allows the use of loci that have shown allelic dropout in kinship analysis as used for disaster victim identification (DVI) and missing person work (MP). This approach uses an extension of a previously published approach to modelling allelic dropout. This method may salvage some information in cases where allelic dropout is hindering DVI or MP work particularly in reconciliations involving a large number of bodies and pedigrees. It should not replace the pursuit of more complete DNA profiles by the normal rework process for such samples.  相似文献   
823.
A method was developed for simultaneously analyzing cocaine (COC), benzoylecgonine (BZE), norbenzoylecgonine (BNE), norcocaine (NCOC), ecgonine (ECG), ecgonine methyl ester (EME), m-hydroxybenzoylecgonine (HBZE), anhydroecgonine methyl ester (AEME), cocaethylene (CE), norcocaethylene (NCE), and ecgonine ethyl ester (EEE) in blood, urine, and muscle. Available deuterated analogs of these analytes were used as internal standards. Proteins from blood and muscle homogenate were precipitated with cold acetonitrile. After the removal of acetonitrile by evaporation, the supernatants and urine were subjected to solid-phase extraction. The eluted analytes were converted to their hydrochloride salts and derivatized with pentafluoropropionic anhydride and 2,2,3,3,3-pentafluoro-1-propanol. The derivatized products were analyzed by a gas chromatograph (GC)/mass spectrometer by selected ion monitoring. The limit of detection (LOD) for COC, BZE, NCOC, EME, CE, NCE, and EEE was 2ng/ml, while the LODs for BNE, ECG, HBZE, and AEME were 25, 640, 50, and 13 ng/ml, respectively. This method was successfully applied in analyzing 13 case samples from aviation accident pilot fatalities and motor vehicle operators. AEME concentrations found in the 13 samples were consistent with those produced solely by the GC inlet pyrolysis of COC controls in blood. Anhydroecgonine cannot be used as a marker for the abuse of COC by smoking because it is also pyrolytically produced from COC metabolites on the GC inlet. The developed method can be effectively adopted for analyzing COC and related compounds in urine, blood, and muscle by a single extraction with increased sensitivity through formation of hydrochloride salts and using a one-step derivatization.  相似文献   
824.
This study provides an empirical analysis of the effects of advertising and commercial practice on the price and quality of optometrists' services. Data were collected by actually purchasing eye examinations and eyeglasses from optometrists in cities with and without restrictions on advertising and commercial practice. Analysis of the data supports the view that advertising and commercial practice lower prices but do not lower the quality of professional care available in the market. The implications of these findings are discussed.  相似文献   
825.
826.
John Kobol 《Society》1981,18(3):77-81
  相似文献   
827.
828.
829.
830.
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