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   12672篇
  免费   351篇
各国政治   655篇
工人农民   422篇
世界政治   818篇
外交国际关系   392篇
法律   7965篇
中国共产党   7篇
中国政治   81篇
政治理论   2587篇
综合类   96篇
  2020年   146篇
  2019年   196篇
  2018年   305篇
  2017年   318篇
  2016年   333篇
  2015年   265篇
  2014年   245篇
  2013年   1155篇
  2012年   290篇
  2011年   335篇
  2010年   280篇
  2009年   356篇
  2008年   380篇
  2007年   409篇
  2006年   412篇
  2005年   316篇
  2004年   305篇
  2003年   300篇
  2002年   310篇
  2001年   467篇
  2000年   410篇
  1999年   326篇
  1998年   175篇
  1997年   135篇
  1996年   144篇
  1995年   138篇
  1994年   145篇
  1993年   140篇
  1992年   244篇
  1991年   262篇
  1990年   250篇
  1989年   258篇
  1988年   236篇
  1987年   236篇
  1986年   271篇
  1985年   273篇
  1984年   233篇
  1983年   224篇
  1982年   156篇
  1981年   138篇
  1980年   114篇
  1979年   160篇
  1978年   93篇
  1977年   112篇
  1976年   95篇
  1975年   72篇
  1974年   91篇
  1973年   86篇
  1972年   80篇
  1971年   69篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
901.
This study examined effects of clothing cues on children's identification accuracy from lineups. Four- to 14-year-olds (n = 228) saw 12 video clips of individuals, each wearing a distinctly colored shirt. After watching each clip children were presented with a target-present or target-absent photo lineup. Three clothing conditions were included. In 2 conditions all lineup members wore the same colored shirt; in the third, biased condition, the shirt color of only one individual matched that seen in the preceding clip (the target in target-present trials and the replacement in target-absent trials). Correct identifications of the target in target-present trials were most frequent in the biased condition, whereas in target-absent trials the biased condition led to more false identifications of the target replacement. Older children were more accurate than younger children, both in choosing the target from target-present lineups and rejecting target-absent lineups. These findings suggest that a simple clothing cue such as shirt color can have a significant impact on children's lineup identification accuracy.  相似文献   
902.
Suppression of environmental science   总被引:1,自引:0,他引:1  
  相似文献   
903.
Sudden unexpected death in an infant caused by or associated with neoplasm is rare. We describe a case of a sudden death in an apparently healthy 3-month-old female, in which the autopsy revealed a multiple type II infantile hepatic hemangioendothelioma (IHE). This uncommon tumor has, untreated, a relatively high mortality rate, mainly due cardiac failure resulting from massive arteriovenous shunts, but the association with sudden infant death is very rare.  相似文献   
904.
Criminologists increasingly have studied the effects of criminal justice contact on a broad range of offenders' adult outcomes. However, virtually all of this research focuses exclusively on street-level offenders. With the use of a unique data set that includes street-level and white-collar offenders, we investigated the odds of regaining steady employment following criminal justice contact by offender type. Specifically, we investigated the effects of age of onset, number of prior arrests, total time sentenced, timing of first arrest, and timing of first incarceration on employment stability for both types of offenders, while controlling for family background factors, race, educational attainment, and age. Overall, we found that white-collar offenders are better able to rebound following contact with the criminal justice system. However, when the accrue multiple arrests and are arrested or incarcerated before the age of 24, white-collar offenders face the same obstacles to employment stability as their street-level counterparts.  相似文献   
905.
This study examined whether sexual abuse was related to higher levels of psychological distress among incarcerated youth and if the effects were invariant across gender. Participants were male and female adolescents, aged 11 to 20 years, incarcerated in six juvenile correctional institutions in five states. Using data from a national study of juveniles confined to secure institutions, this study assessed the relationship between gender, sexual abuse, and depression. Adolescents who were sexually abused during childhood compared to adolescents who were not report higher levels of depression. Sexually abused girls and boys report higher levels of depression compared to boys not sexually abused. These findings suggest the importance of understanding the relationship between childhood sexual abuse and depressive symptoms among incarcerated youth. Additionally, the findings suggest that the effects of childhood sexual abuse are similar for males and females among a high-risk sample of institutionalized juvenile delinquents. Implications for treatment of incarcerated youth are discussed.  相似文献   
906.
907.
A total of 137 urine samples and 46 serum samples, corresponding to 154 self-confessed designer drugs consumers in Ibiza island, were analyzed for the presence of designer drugs: amphetamine and amphetamine derivatives (methamphetamine, methylenedioxymethamphetamine (MDMA), methylenedioxyethylamphetamine (MDEA), methylenedioxyamphetamine (MDA), p-methoxymethylamphetamine (PMMA), p-methoxyamphetamine (PMA), etc.), ketamine and gamma-hydroxybutyric acid. Among this population, coming both from the forensic clinic and from the emergency room of a hospital, a total of 99 cases were found positive for some designer drug. This study shows the prevalence of methylenedioxymethamphetamine (MDMA) among designer drug users, sole or in association with other drugs. Also, the mixture of MDMA with other designer drugs, ethanol and/or cocaine is shown to be more likely to produce toxic symptoms requiring clinical attendance in a hospital emergency room. These findings along with the consumption history, the concentrations of drugs and metabolites in urine and serum and the toxicological significance for the interpretation of some MDMA metabolites such as 4-hydroxy-3-methoxymethamphetamine (HMMA) are discussed in this study.  相似文献   
908.
Downstairs falls frequently occur within domestic environments and are mainly associated with elderly and intoxicated individuals, often feature multiple injuries on various parts of the body. In most cases it is not possible to determine the cause of the fall and/or death solely by means of external examination. In this retrospective study, which covers a period of 11 years, all cases of death which included a fall downstairs in their case history, were collected from the Forensic Institutes of the Universities of Bonn and Greifswald, Germany. Falls downstairs made up to 2% (166 cases) of all postmortem examinations carried out within this period. Interestingly, almost double of the amount of such falls applied to males as to females. The primary cause of death was cranio-cerebral trauma and the vast majority of skull injuries associated with falls downstairs were found above 'the hat brim line'. Injuries were also often found on several other parts of the body at once. Nineteen of the 116 examined individuals exhibited agonal injuries. In these cases, postmortem examination revealed pre-existing disease or intoxication to be the cause of death and thus, cause of the fall. The injury pattern only allows a tendency towards vital or agonal incident as a conclusion.  相似文献   
909.
Y-STR polymorphism in Central Anatolian Region of Turkey   总被引:2,自引:0,他引:2  
Eight Y-chromosome specific STR (Y-STR) loci including DYS19, DYS388, DYS389I, DYS389II, DYS390, DYS391, DYS392 and DYS393 were investigated in a group of males from Central Anatolian Region of Turkey. Healthy 59 males living in this region for at least three generations were included in the study. PCR analysis was carried out with Y-STR specific primers on genomic DNA obtained from peripheral blood samples and size determination of PCR products was performed by silver staining following 6% polyacrylamide gel electrophoresis (PAGE). DYS388 was found to be the locus with lowest diversity (D) whereas DYS389II was the locus with highest diversity. The current study presented a framework of variation for the eight Y-STR loci in Central Anatolian population.  相似文献   
910.
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