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   3980篇
  免费   141篇
各国政治   146篇
工人农民   138篇
世界政治   239篇
外交国际关系   130篇
法律   2773篇
中国政治   44篇
政治理论   637篇
综合类   14篇
  2023年   25篇
  2021年   31篇
  2020年   60篇
  2019年   61篇
  2018年   89篇
  2017年   105篇
  2016年   89篇
  2015年   75篇
  2014年   96篇
  2013年   308篇
  2012年   96篇
  2011年   117篇
  2010年   86篇
  2009年   92篇
  2008年   116篇
  2007年   88篇
  2006年   114篇
  2005年   90篇
  2004年   105篇
  2003年   100篇
  2002年   93篇
  2001年   191篇
  2000年   133篇
  1999年   105篇
  1998年   38篇
  1997年   48篇
  1996年   37篇
  1995年   50篇
  1994年   45篇
  1993年   55篇
  1992年   82篇
  1991年   87篇
  1990年   79篇
  1989年   63篇
  1988年   85篇
  1987年   81篇
  1986年   98篇
  1985年   110篇
  1984年   86篇
  1983年   81篇
  1982年   39篇
  1981年   36篇
  1979年   35篇
  1978年   33篇
  1975年   31篇
  1974年   45篇
  1972年   27篇
  1971年   31篇
  1970年   30篇
  1968年   32篇
排序方式: 共有4121条查询结果,搜索用时 0 毫秒
151.
Indigenous vegetables play an important role in Kenyan food security, but production is limited by poor seed quality. Traditionally, seeds have been traded through informal networks, but a new formal seed sector is emerging. This study assessed the relative potential for formal or informal seed systems to meet the need for high-quality indigenous vegetable seed. By evaluating determinants of farmers’ seed purchasing behaviour, we conclude that informal seed systems have greater potential to meet this need and should be strengthened. This study suggests that policy-makers should use context-specific data to guide decisions on seed policy.  相似文献   
152.
  • Application of an issues management approach to corporate social responsibility consists of identifying, evaluating and responding to those issues that an industry must address in order to be socially responsible. This research focussed on identifying social and environmental issues relevant to the US forest products manufacturing industry. Towards this end, 14 interviews were conducted with key‐informants drawn from non‐government organizations, government and political offices, forest products associations, a multilateral organization and an extension expert. A rich set of issues was generated covering social and environmental issues. However, such a set may contain issues that are far too radical and may be challenging for companies to pursue. Accordingly, in order to develop a doable, socially credible and concise set of issues, a Delphi technique was employed consisting of forest products management and marketing academicians from various US universities. A two‐round Delphi resulted in identification of six social and six environmental issues that the US forest products manufacturing industry must address in order to be socially responsible. This proposed two‐stage process may have special relevance for companies that are entering into new markets overseas.
Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   
153.
The National Oceanic and Atmospheric Administration instituted a Planning, Programming, Budgeting, and Execution System (PPBES) in 2002. As supplemented by matrix management, PPBES was appealing as an effort to rationalize the performance of an agency with an especially high degree of functional overlap among its component parts. Although PPBES has had some salutary effects, the agency's experience to date consistent with accounts of the difficulties that led to the abandonment of program budgeting by the civilian bureaucracy almost 40 years ago. As such, it speaks to the limits of performance assessment as a means of reallocating resources and responsibilities across organizational boundaries.  相似文献   
154.
In this study, we consider the efficacy of a relatively new and widely accepted certification system for teachers established by the National Board for Professional Teaching Standards (NBPTS). We utilize an extensive database covering the universe of teachers and students in Florida for a four‐year span to determine the relationship between NBPTS certification and the impact of teachers on student test scores from both low‐stakes and high‐stakes exams. Contrary to some previous studies, we find evidence that NBPTS certification provides a positive signal of a teacher's contribution to student achievement only in a few isolated cases. However, our results do reinforce evidence from previous research that the process of becoming NBPTS certified does not increase teacher productivity. © 2009 by the Association for Public Policy Analysis and Management.  相似文献   
155.
156.
This article takes a state's eye view of trends towards a more centralised system of governance in Australia. It argues that while globalisation strengthens the roles of national governments it also provides less noticed public policy and management opportunities for sub-national governments. The article shows how state governments in Australia can use high-level policy proposals to reinforce their continuing relevance as key members of a federal system of government. It proposes that skilful deployment of policy ideas and analyses can enable the states to sustain alternative national agendas despite hostility or lack of interest by the federal government. In conclusion, the article examines the implications for federal-state relations under the Rudd government. It suggests that the elements for productive reform agendas are present but that bringing them together will require considerable effort.  相似文献   
157.
Physiologic reactivity to racially rejecting images was assessed in 35 young adults (10 males, 25 female) from African-American backgrounds using the startle probe paradigm. In a laboratory setting, participants viewed 16 images depicting racial rejection, racial acceptance, nonracial negative, and nonracial positive themes. While viewing these images, startling bursts of noise were presented and the magnitude of the eyeblink responses were measured. Results supported an attentional mechanism which suggests that, while viewing both racially rejecting and nonracial positive images, individuals may be so absorbed in processing the images that they appear less distracted by the startling noise. However, these patterns were only found for participants low in racial regard. Young adults who felt positively about their racial background did not exhibit differential processing of startle stimuli as a function of slide themes. Race-rejection sensitivity did not moderate startle reactivity. Developmental implications, particularly in light of coping with racial discrimination, are discussed.
Lisa KiangEmail:
  相似文献   
158.
Jessica N. Pabón interviews graffiti artist Abby Andrews, a.k.a. AbbyTC5, about her canvas painting Queens, the image on the front cover of the special issue.  相似文献   
159.
Previous studies have indicated homophily in depressive symptoms among adolescent friends, resulting from both peer selection and socialization processes. However, developmental differences and the role of school transitions in these processes have not been elucidated. A sample of 367 (51% female) adolescents was followed from 6th to 11th grade to investigate prospective relationships between adolescents’ and their friends’ depressive symptoms in middle school and in high school. Results revealed that students selected friends with similar levels of depressive symptoms after each school transition. Additionally, friends appeared to socialize adolescents to become more similar in depressive affect in late middle school years. These findings suggest normative selection effects after school transitions, followed by socialization effects in middle school, but not high school.  相似文献   
160.
Despite evidence that neighborhoods confer both risk and resilience for youth development, the existing neighborhood research has a number of methodological limitations including lack of diversity in neighborhoods sampled and neighborhood characteristics assessed. The purpose of this study was to address these methodological limitations of existing research and to examine the relationship of neighborhood structural and social characteristics to family-level social processes and teacher-reported social competence during early adolescence. The study sample of 3,624 fifth graders (51?% girls) was ethnically diverse, including roughly even proportions of non-Hispanic White, non-Hispanic Black, and Hispanic youth. Neighborhood measures included economic disadvantage derived from the U.S. Census, physical and social disorder obtained by direct observation, and social capital from parental reports. Family-level social processes included parent reported family cohesion and youth reported maternal and paternal nurturance. We found that neighborhood factors significantly associated with youth social aggression and social competence but not social withdrawal, after controlling for individual demographic characteristics and parenting factors. There was limited evidence of moderation of family influences by neighborhood characteristics as well as the moderation of neighborhood effects by children’s gender. Neighborhood physical disorder was associated with increased social aggression among boys but with increased social withdrawal among girls. Implications of the study’s findings for research on neighborhoods and adolescent development and the development of preventive interventions 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