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   1099篇
  免费   39篇
各国政治   51篇
工人农民   87篇
世界政治   114篇
外交国际关系   80篇
法律   514篇
中国共产党   1篇
中国政治   6篇
政治理论   278篇
综合类   7篇
  2023年   8篇
  2022年   12篇
  2021年   14篇
  2020年   47篇
  2019年   39篇
  2018年   45篇
  2017年   40篇
  2016年   40篇
  2015年   47篇
  2014年   40篇
  2013年   166篇
  2012年   41篇
  2011年   31篇
  2010年   42篇
  2009年   37篇
  2008年   28篇
  2007年   43篇
  2006年   32篇
  2005年   37篇
  2004年   31篇
  2003年   28篇
  2002年   20篇
  2001年   23篇
  2000年   35篇
  1999年   18篇
  1998年   20篇
  1997年   14篇
  1996年   9篇
  1995年   12篇
  1994年   11篇
  1993年   9篇
  1992年   8篇
  1991年   11篇
  1990年   9篇
  1989年   14篇
  1988年   11篇
  1987年   10篇
  1986年   6篇
  1985年   5篇
  1984年   10篇
  1983年   6篇
  1982年   4篇
  1981年   2篇
  1980年   2篇
  1979年   5篇
  1978年   3篇
  1977年   3篇
  1975年   2篇
  1974年   2篇
  1969年   2篇
排序方式: 共有1138条查询结果,搜索用时 15 毫秒
181.
ARPA-E offers a new innovation institutional model to meet energy technology challenges. Because it is explicitly based on DARPA, this article reviews the noted DARPA approach in detail. Briefly citing well-known features of DARPA, it explores a number of important features that have not been well discussed in the policy literature on DARPA. These include DARPA??s ability to undertake multigenerational technology thrusts, the synergies it has been able to create through complementary strategic technologies, its ability to build an advocate community, and connections it has built to larger innovation elements downstream from DARPA. It has also taken on incumbent technologies within both DOD and in the private sector, used ties to DOD leadership to press its advances, and supported initial market creation. The article then reviews the new ARPA-E model in detail, commenting first on how ARPA-E has adopted key DARPA approaches. It then discusses new features ARPA-E is adopting, driven by the unique demands of the complex, established energy sector. These include new ways: (1) to sharpen the research visioning, selection and support processes, (2) to build a community of support, important to its political survival, and (3) to implement technologies it supports. In addition, the further DARPA features enumerated above provide potentially useful future guideposts to ARPA-E. The paper closes with a discussion of the difficult technology implementation problems on the ??back end?? of the innovation system??including demonstrations, test beds, and initial markets. The article posits that both agencies must further address these implementation issues by fostering additional downstream partnerships, including between government and private sector.  相似文献   
182.
Parametric insurance is a promising alternative to traditional insurance when it comes to addressing catastrophic weather events and their impact on developing nations. Where available, traditional insurance is expensive and can involve protracted claim adjustment. Parametric insurance, on the other hand, provides coverage monies automatically upon the existence of certain objective weather-related parameters based upon a set formula. This model has been shown to work in the Caribbean Basin, but requires international cooperation in pooling, measuring, and managing risk. The immediate availability of emergency-response funds can be crucial in mitigating the impacts of climate change and related severe weather events.  相似文献   
183.
Increasing politicization in EU member states about European issues can be expected to strengthen the impact of attitudes towards Europe on vote choice in European Parliament (EP) elections. At the same time this impact is likely to vary between voters and contexts as a function of political information. This study explores the role of political information in explaining individual and contextual heterogeneity in the degree of EU issue voting. Using a two-step hierarchical estimation procedure to explore both individual and contextual variation, we show that while EU issue voting in the 2009 EP elections is only slightly more pronounced among the politically sophisticated, it is clearly more extensive in contexts that provide higher levels of political information on European matters.  相似文献   
184.
Abstract: In the present study, ultrastructural analysis of mitochondrial deposits (black dots within mitochondria) as a method for the detection of early acute myocardial infarction (AMI) was evaluated. In 24 patients with AMI and six controls, analysis was performed in the heart of infarcted patients and noninfarcted controls. In the infarction area in lactate dehydrogenase (LDH)‐diagnosed AMI, the percentage of positive mitochondria was significantly higher compared to corresponding heart tissue in control patients and compared to noninfarcted areas within these patients. Also in patients with a clinically diagnosed AMI but no LDH decoloration, a significant higher percentage of positive mitochondria was found in the left ventricle compared to controls and noninfarcted areas. In patients with AMI, an increase in mitochondria with deposits was found in the infarction area compared to controls and noninfarcted tissue within the same patient, suggesting that electron microscopical changes in mitochondria can be used for the diagnosis of AMI less than 3 h old.  相似文献   
185.
Abstract: An online forensic dental identification exercise was conducted involving 24 antemortem–postmortem (AM–PM) dental radiograph pairs from actual forensic identification cases. Images had been digitally cropped to remove coronal tooth structure and dental restorations. Volunteer forensic odontologists were passively recruited to compare the AM–PM dental radiographs online and conclude identification status using the guidelines for identification from the American Board of Forensic Odontology. The mean accuracy rate for identification was 86.0% (standard deviation 9.2%). The same radiograph pairs were compared using a digital imaging software algorithm, which generated a normalized coefficient of similarity for each pair. Twenty of the radiograph pairs generated a mean accuracy of 85.0%. Four of the pairs could not be used to generate a coefficient of similarity. Receiver operator curve and area under the curve statistical analysis confirmed good discrimination abilities of both methods (online exercise = 0.978; UT‐ID index = 0.923) and Spearman’s rank correlation coefficient analysis (0.683) indicated good correlation between the results of both methods. Computer‐aided dental identification allows for an objective comparison of AM–PM radiographs and can be a useful tool to support a forensic dental identification conclusion.  相似文献   
186.
Criminal behavior of parents substantially affects the criminal behavior of children. Little is known, however, about how crime is transmitted from one generation to the next. In order to test two possible explanations against each other, we pose the question whether the timing of the criminal acts of fathers is important for children’s chances of committing crime. Static theories predict that it is the number of delinquent acts performed by fathers that is important, and that the particular timing does not affect the child’s chance of committing crime. Dynamic theories state that the timing is important, and children have a greater chance of committing crime in the period after fathers have committed delinquent acts. Results show that the total number of convictions of a father is indeed very important, but also the exact timing is key to understanding intergenerational transmission of crime. In the year a father is convicted the chance his child is also convicted increases substantially and it decays in subsequent years. This decay takes longer the more crimes father has committed. Our results show that some of the assumptions of the static theories at least need to be adjusted.  相似文献   
187.
Legal socialization theory predicts that attitudes mediate the relation between legal reasoning and rule-violating behavior [Cohn, E. S., & White, S. O. (1990). Legal Socialization: A Study of Norms and Rules. New York: Springer-Verlag]. Moral development theory predicts that moral reasoning predicts rule-violating behavior directly as well as indirectly [Blasi, A. (1980). Bridging moral cognition and moral action: A critical review of the literature. Psychological Bulletin, 88, 1–45]. We present and test an integrated model of rule-violating behavior drawing on both theories in a longitudinal study of middle school and high school students. Students completed questionnaires three times during the course of 1 year at 6-month intervals. Legal and moral reasoning, legal attitudes, and rule-violating behavior were measured at times one, two, and three respectively. Structural equation models revealed that while moral and legal reasoning were directly and indirectly related to rule-violating behavior among high school students, legal reasoning bore no direct relation to rule-violating behavior among middle school students. The implications for an integrated model of reasoning and rule-violating behavior are discussed.  相似文献   
188.
Die Europ?ische Union und die Bundesrepublik Deutschland sind hinsichtlich des Anbaus gentechnisch ver?nderter Organismen (GVO) sehr zurückhaltend, w?hrend au?erhalb Europas die Zahl der angebauten gentechnisch ver?nderten Kulturpflanzen stetig zunimmt. Die Anwesenheit von GVO, die nicht zum Anbau zugelassen sind, in Saatgut ist deshalb ein wiederkehrendes Problem mit wachsender Bedeutung. Der Beitrag analysiert die dazu vorliegende Rechtsprechung der Verwaltungsgerichte und demonstriert am jüngsten Fall der Saatgutkontamination (NK603-Spuren in Maissaatgut) die Anwendung des differenzierten Regelungssystems des GenTG, das den Vollzugsbeh?rden anspruchsvolle Ermittlungsund Abw?gungspflichten auferlegt.  相似文献   
189.
190.
Family‐centered care during adolescent detention aims to increase parental participation in an attempt to optimize treatment outcomes. However, little is known about parents’ needs in family‐centered care. To fill this gap, we interviewed 19 purposefully selected parents of detained adolescents using a semi‐structured topic list. Although needs differed between parents, they were generally interested in activities that included spending time with their child. It is important for parents to receive timely information about their child's condition and treatment, detention procedures, and activities in the facility. The outcomes demonstrated that parents expected a two‐way communication based on respect and reliability.  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