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   5872篇
  免费   122篇
各国政治   253篇
工人农民   225篇
世界政治   470篇
外交国际关系   209篇
法律   3660篇
中国政治   49篇
政治理论   1111篇
综合类   17篇
  2021年   40篇
  2020年   69篇
  2019年   105篇
  2018年   131篇
  2017年   116篇
  2016年   119篇
  2015年   69篇
  2014年   121篇
  2013年   595篇
  2012年   149篇
  2011年   155篇
  2010年   127篇
  2009年   141篇
  2008年   172篇
  2007年   160篇
  2006年   141篇
  2005年   132篇
  2004年   157篇
  2003年   126篇
  2002年   103篇
  2001年   311篇
  2000年   279篇
  1999年   195篇
  1998年   80篇
  1997年   80篇
  1996年   55篇
  1995年   57篇
  1994年   50篇
  1993年   40篇
  1992年   122篇
  1991年   140篇
  1990年   136篇
  1989年   129篇
  1988年   117篇
  1987年   126篇
  1986年   103篇
  1985年   99篇
  1984年   99篇
  1983年   83篇
  1982年   62篇
  1981年   77篇
  1980年   37篇
  1979年   75篇
  1978年   47篇
  1975年   40篇
  1974年   51篇
  1973年   56篇
  1972年   40篇
  1971年   34篇
  1970年   31篇
排序方式: 共有5994条查询结果,搜索用时 15 毫秒
861.
Prisoners' forecasts of post-release success may have implications for how they respond to imprisonment, release, and parole decisions. We examined sentenced US and UK prisoners' forecasts of recidivism, and how well UK prisoners believed they would fare compared to the average other prisoner. In both samples, forecasts of recidivism were unrealistically optimistic when compared to official statistics on recidivism. UK prisoners also demonstrated a self-enhancement bias by forecasting that they were less likely to re-offend than other prisoners. Prisoners' forecasts of recidivism were predicted by only a few of the pre-prison, in-prison, and post-prison factors that have been shown to be associated with actual recidivism. We discuss the implications of these findings and propose avenues for future research.  相似文献   
862.
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   
863.
X-chromosomal markers are particularly useful for solving complex problems relating to kinship and deficiency paternity analysis. In the present study, population genetics data of four X-chromosomal short tandem repeats (STRs) DXS8378, HPRTB, DXS7423 and DXS7132 were obtained by analyzing 500 unrelated Chinese individuals (250 males and 250 females). Population genetics data obtained from the Chinese were compared with those of the Asian and European population. Mutations in X-chromosomal markers were analyzed based on a total of 61 proven father-child and 45 proven mother-child pairs.  相似文献   
864.
865.
866.
867.
868.
869.
870.
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