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   846篇
  免费   53篇
各国政治   74篇
工人农民   89篇
世界政治   79篇
外交国际关系   47篇
法律   429篇
中国共产党   1篇
中国政治   6篇
政治理论   172篇
综合类   2篇
  2024年   1篇
  2023年   6篇
  2022年   4篇
  2021年   9篇
  2020年   30篇
  2019年   38篇
  2018年   51篇
  2017年   56篇
  2016年   56篇
  2015年   29篇
  2014年   49篇
  2013年   148篇
  2012年   31篇
  2011年   39篇
  2010年   34篇
  2009年   31篇
  2008年   24篇
  2007年   29篇
  2006年   23篇
  2005年   35篇
  2004年   25篇
  2003年   35篇
  2002年   26篇
  2001年   8篇
  2000年   8篇
  1999年   3篇
  1998年   7篇
  1997年   7篇
  1996年   9篇
  1995年   9篇
  1994年   3篇
  1993年   5篇
  1992年   3篇
  1991年   5篇
  1990年   2篇
  1989年   2篇
  1988年   2篇
  1987年   5篇
  1986年   1篇
  1985年   2篇
  1984年   2篇
  1983年   2篇
  1980年   2篇
  1979年   1篇
  1978年   1篇
  1976年   1篇
排序方式: 共有899条查询结果,搜索用时 31 毫秒
851.
852.
Oral fluid (collected with the Intercept((R)) device) and plasma samples were obtained from 139 individuals suspected of driving under the influence of drugs and analyzed for Delta(9)-tetrahydrocannabinol (THC), the major psychoactive constituent of cannabis, using a validated quantitative LC-MS-MS method. The first aim of the study was to investigate the correlation between the analytical data obtained in the plasma and oral fluid samples, to evaluate the use of oral fluid as a 'predictor' of actual cannabis influence. The results of the study indicated a good accuracy when comparing THC detection in oral fluid and plasma (84.9-95.7% depending on the cut-off used for plasma analysis). ROC curve analysis was subsequently used to determine the optimal cut-off value for THC in oral fluid with plasma as reference sample, in order to 'predict' a positive plasma result for THC. When using the LOQ of the method for plasma (0.5 ng/mL), the optimal cut-off was 1.2 ng/mL THC in oral fluid (sensitivity, 94.7%; specificity, 92.0%). When using the legal cut-off in Belgium for driving under the influence in plasma (2 ng/mL), an optimal cut-off value of 5.2 ng/mL THC in oral fluid (sensitivity, 91.6%; specificity, 88.6%) was observed. In the second part of the study, the performance of the on-site Dr?ger DrugTest for the screening of THC in oral fluid during roadside controls was assessed by comparison with the corresponding LC-MS-MS results in plasma and oral fluid. Since the accuracy was always less than 66%, we do not recommend this Dr?ger DrugTest system for the on-site screening of THC in oral fluid.  相似文献   
853.
854.
Population genetic data for the 15 STRs included in the AmpFlSTR Identifiler kit were obtained from a sample of 168 unrelated individuals of the ethnic group of Polish Tatars residing in the Northeastern Poland. Significant differences revealed in relation to the autochthonous Poles by using R x C test as well as F(ST) and F(IS) estimates suggest that the ethnic group of Polish Tatars is a distinct genetic community.  相似文献   
855.
Quadruplex and pentaplex systems for polymerase chain reaction amplification of X-chromosomal short tandem repeats DXS101, HPRTB, DXS8377, DXS981 (STRX1) and DXS6789 were developed for automated profiling of liquid and membrane-bound DNA samples. Chinese, Japanese and Thai populations were typed using a quadruplex system, while German and Philippine populations were analyzed using a five-locus system. Out of 88 meioses studied in Philippine family samples at each locus, a possible one repeat deletion (allele 51 to 50) at DXS8377 was observed in a father-daughter pair. Exact tests performed on genotype data from females in the Philippine, German and Thai populations indicated that these groups conform to Hardy-Weinberg equilibrium. Exact tests for population differentiation indicate significant variations in allele distributions, particularly at loci DXS101, DXS981 and DXS6789. Considered individually, DXS8377 was the most polymorphic and HPRTB the least polymorphic locus in these five populations. When the forensic efficiency of the quadruplex system was calculated, the combined power of discrimination among males (PD(M)) was no lower than 0.998, while among females the combined PD(F) was at least 0.9999 in all populations. The combined power of paternity exclusion was a minimum of 0.998 in trio cases and 0.98 in motherless cases. The addition of locus DXS6789 to the German and Philippine population databases using a pentaplex increased the forensic efficiency of the analysis system.  相似文献   
856.
Although a major predictor of sexual victimization is previous victimization, the mechanism underlying this effect is not well understood. Sexual assault history's impact on appraisal of and responses to sexual assault risk was examined in an experimental analog study. Intimacy with perpetrator was also examined as a potential contributor to appraisal and responses. Young women varying in sexual assault history were randomly assigned to receive a scenario in which type of perpetrator was manipulated (someone just met, friend, date, boyfriend). Respondents appraised the man's actions as sexual interest or assault and indicated intentions to respond (resistance and nonresistance). Sexual assault history did not directly influence appraisal or intended responses but had modest indirect effects on resistance via sexual assertiveness. The primary influence on appraisal and responses was perpetrator intimacy. Women facing advances within a more intimate relationship were less likely to appraise those advances as threatening and less likely to resist.  相似文献   
857.
858.
Sixty proband children (P) of bipolar I parents and 60 control children of normal parents (C), in the age range 10–17, were investigated clinically by K-SADS-E interview and psychologically by personality inventories. In the global psychopathology rate of 63% in P children and 25% in C children, depressive disorders reached 8% in P children and 0% in C children, while depressive personality traits reached 22% in P children and 15% in C children. Cluster analysis evidenced a variety of personality structures, but 3 clusters were striking: a cluster characterized by high anxiety and depressive reactivity (17% P and 5% C children), a cluster characterized by high depressive reactivity and emotional instability (5% P children), and a hyperthymic cluster (5 % P children). Sixty-seven percent of P children and 36% of C children showed deviant personality traits (p<.01).  相似文献   
859.
In September 1990 we became involved with the Centre for the Defence of the Child (CDM) in Brazil, hoping to participate in a survey of the lives of street children that was being conducted by the group. The CDM, a branch of its parent organisation The Young Street Vendors' Association, takes on individual cases of street children, providing crisis management with social, psychological, and legal support. It was decided to start a project of regularly taking a team of staff on to the streets and into the areas where the street children were, with the aim of providing a programme of support and self-esteem building, principally for the street girls. This project proved a success with the street children and remains so following our departure from Brazil.  相似文献   
860.
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