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   10316篇
  免费   371篇
各国政治   676篇
工人农民   436篇
世界政治   810篇
外交国际关系   470篇
法律   5930篇
中国共产党   2篇
中国政治   154篇
政治理论   2110篇
综合类   99篇
  2023年   60篇
  2020年   158篇
  2019年   191篇
  2018年   252篇
  2017年   276篇
  2016年   296篇
  2015年   234篇
  2014年   261篇
  2013年   1280篇
  2012年   295篇
  2011年   358篇
  2010年   267篇
  2009年   282篇
  2008年   298篇
  2007年   290篇
  2006年   274篇
  2005年   246篇
  2004年   258篇
  2003年   276篇
  2002年   214篇
  2001年   371篇
  2000年   346篇
  1999年   313篇
  1998年   157篇
  1997年   111篇
  1996年   118篇
  1995年   112篇
  1994年   115篇
  1993年   105篇
  1992年   178篇
  1991年   163篇
  1990年   151篇
  1989年   148篇
  1988年   164篇
  1987年   162篇
  1986年   165篇
  1985年   151篇
  1984年   148篇
  1983年   159篇
  1982年   96篇
  1981年   68篇
  1980年   84篇
  1979年   98篇
  1978年   78篇
  1977年   67篇
  1976年   69篇
  1975年   60篇
  1972年   54篇
  1971年   55篇
  1969年   57篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
891.
892.
893.
894.
A portable case has been developed by which cyanoacrylate (super glue) fuming can be used inside a vehicle suspected of being involved in serious crime. The car itself serves as a fumigation chamber and the cyanoacrylate vapours are fed into the car via a hose. Connected to the hose and suspended inside the car is a vapour diffuser. The cyanoacrylate originates from a portable case where there is a sealed heater and also a command panel with hygrometer and thermometer for a technician to control the process. There is also space inside the case for other necessary equipment.  相似文献   
895.
896.
897.
Abstract. This paper investigates the implications for public policy in general and merger sections of the Combines Act in particular of the hypothesis that bureaus, when carrying out their administrative duties, attempt to maximize their private utility functions rather than the social utility function expressed in the legislation. The analytical procedure, given alternative utility goals of power, prestige, convenience, and security and the appropriate constraints, is to predict the behaviour of the Combines Branch (from 1960–71) and to test these predictions against actual Branch behaviour. The evidence on the Branch's behaviour (all cases prosecuted and discontinued) suggests that its conduct can be better explained by security maximization than by any alternative private or altruistic goal. However, it is not clear that this was a bad thing for public policy because it can be argued that the Branch's behaviour brought public policy in this area closer to the social welfare function implied in the legislation than would have been the case if the government had successfully maximized its private utility function. Sommaire. L'auteur de cet exposé enquête sur les implications, pour la politique publique en général et les articles sur le fusionnement de la loi sur les coalitions en particulier, de l'hypothèse suivant laquelle es bureaux, dans l'exercice de leurs responsabilités administratives, essaient de maximiser leurs fonctions privées plutôt que leur fonction sociale, telle qu'elle est indiquée dans la législation. La procédure analytique, étant donné le choix des buts: pouvoirs, prestige, commodité et sécurité, avec Ies limites appropriées, consiste à prédire le comportement du service chargé des coalitions (de 1965 à 1971) et à vérifier ces prédictions à la lumière de son comportement réel. Les faits relatifs au comportement de ce service (tous les cas amenés en justice et ceux qui ont été abondonnés) indiquent qu'il s'explique plus par une maximisation de la sécurité que par tout autre motif privé ou altruiste. Il ne semble pas cependant que cela ait été néfaste à la politique publique parce que l'on peut argumenter que le comportement du service a fait jouer à la politique publique un rôle plus orienté vers le bien-être social, comme cela était sous-entendu dam la législation, que ce n'aurait été le cas si le gouvernement avait maximisé avec succès sa fonction privée.  相似文献   
898.
Tests that infer the ancestral origin of a DNA sample have considerable potential in the development of forensic tools that can help to guide crime investigation. We have developed a single-tube 34-plex SNP assay for the assignment of ancestral origin by choosing ancestry-informative markers (AIMs) exhibiting highly contrasting allele frequency distributions between the three major population-groups. To predict ancestral origin from the profiles obtained, a classification algorithm was developed based on maximum likelihood. Sampling of two populations each from African, European and East Asian groups provided training sets for the algorithm and this was tested using the CEPH Human Genome Diversity Panel. We detected negligible theoretical and practical error for assignments to one of the three groups analyzed with consistently high classification probabilities, even when using reduced subsets of SNPs. This study shows that by choosing SNPs exhibiting marked allele frequency differences between population-groups a practical forensic test for assigning the most likely ancestry can be achieved from a single multiplexed assay.  相似文献   
899.
The aim of this study was to determine whether polyurethane (PU) foam fragments from different sources could be discriminated from each other. Low and high power microscopy was used to determine whether or not foam fragments were distinguishable from each other under various lighting conditions. Once similar foam fragments were declared microscopically indistinguishable, the visible range microspectrophotometer was highly competent in further distinguishing the spectral characteristics in various fragments from each other. Foam fragments from the same source were shown to display no microscopical or chemical variation. Conversely, it was possible to make clear distinctions between foam fragments from different sources.  相似文献   
900.
This study assessed the associations of characteristics of domestic violence incidents with clinically significant levels of traumatic symptoms and behavioral problems in a socio-economically and ethnically mixed sample of 687 children participating in a community-service program for children witnessing violence. Study predictors included child/family demographic characteristics, type and chronicity of exposure, and child’s perceptions of control over the event and threat to personal safety. Outcomes consisted of traumatic symptoms and behavior problems. Results showed that perceived threat and control were associated with greater odds of clinically significant levels of several trauma symptoms (and behavior problems in the case of perceived threat) after adjusting for effects of demographic factors and violence characteristics. Child co-victimization increased odds of reaching clinically significant levels of traumatic symptoms compared to children who witnessed the event but were not victimized. Female sex and White ethnicity increased odds of specific trauma symptoms and behavior problems. Increasing age reduced odds of some trauma symptoms. Associations between predictors and one outcome measure did not generalize across the other outcome measure. Implications of study findings, and directions for future research are discussed.  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