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   2399篇
  免费   476篇
各国政治   511篇
工人农民   72篇
世界政治   252篇
外交国际关系   129篇
法律   983篇
中国政治   37篇
政治理论   857篇
综合类   34篇
  2021年   29篇
  2020年   45篇
  2019年   165篇
  2018年   107篇
  2017年   158篇
  2016年   164篇
  2015年   146篇
  2014年   130篇
  2013年   757篇
  2012年   103篇
  2011年   106篇
  2010年   110篇
  2009年   52篇
  2008年   77篇
  2007年   58篇
  2006年   49篇
  2005年   28篇
  2004年   41篇
  2003年   25篇
  2002年   31篇
  2001年   15篇
  2000年   29篇
  1999年   21篇
  1998年   17篇
  1997年   22篇
  1996年   16篇
  1995年   21篇
  1994年   19篇
  1993年   19篇
  1992年   18篇
  1991年   9篇
  1990年   17篇
  1989年   9篇
  1988年   17篇
  1987年   16篇
  1986年   19篇
  1985年   11篇
  1984年   17篇
  1983年   13篇
  1982年   16篇
  1981年   12篇
  1979年   10篇
  1978年   10篇
  1977年   12篇
  1976年   9篇
  1975年   8篇
  1974年   15篇
  1973年   11篇
  1969年   10篇
  1968年   8篇
排序方式: 共有2875条查询结果,搜索用时 0 毫秒
141.
Research into fingermark enhancement techniques has traditionally used visual comparisons and qualitative methods to assess their effectiveness based on the quality of the developed fingermark. However, with increasing research into the optimisation of these techniques the need for a quantitative evaluative method has arisen. Parameters for acceptable fingerprint quality are not well defined and generally encompass clear, sharp edges and high levels of contrast between the fingermark ridges and background material. Using these current parameters, a conclusive measurement of fingerprint quality and thus the effectiveness of development techniques cannot be achieved.This study presents a model through which an aspect of fingerprint quality can be objectively and impartially measured based on a relative contrast index, constructed through measuring the reflective intensity of the fingermark ridges against the background material. Using a fibre-optic spectrophotometer attached to a microscope with axial illumination, the intensity counts of the ridge detail and background material were measured and a logarithmic contrast index constructed. The microscope and spectrophotometer parameters were experimentally tested using a standard colour resolution chart with known reflective properties. The protocol was successfully applied to four sample groups: black inked fingerprints on white paper; latent fingermarks on white paper developed separately with ninhydrin and physical developer; and fingermarks in blood deposited on white tiles and enhanced with amido black. The contrast indices obtained quantitatively reflect the level of contrast and provide an indication of fingerprint quality through a numerical representation rather than previous qualitative methods. It has been suggested that the proposed method of fingerprint quantification may be viable for application in the forensic research arena as it allows the definitive measurement of contrast to aid the evaluation of fingermark detection and enhancement techniques.  相似文献   
142.
143.
Abstract: Drawing on a longitudinal study from the early years of implementation of health‐care networks in Quebec, this article describes how public‐sector managers deal with complex challenges when both organizational structures and organizational strategies are radically transformed simultaneously. The new organizations studied had to completely re‐shuffle roles and responsibilities of their management teams while making sense of their new mandate of developing a population‐focused approach to health problems – all the time maintaining day‐to‐day operations. The four health‐care networks studied proceeded somewhat differently to meet these reciprocal challenges. The study reveals the importance of balancing organizing initiatives (focused on structures) with “sense‐making” initiatives (focused on strategies), of developing capacities for sense‐making through the creation of key “sense‐maker/sense‐giver” positions whose occupants are able to ensure that conceptual activities engage people working at different levels, even as organizational structures are in flux, and of mobilizing external constraints and influences as opportunities and resources in sense‐making and organizing. Sommaire : Se fondant sur une étude longitudinale des premières années de la mise en œuvre des réseaux de soins de santé au Québec, cet article décrit la manière dont les gestionnaires du secteur public font face à des défis complexes, alors que les structures et les stratégies organisationnelles sont radicalement transformées simultanément. Les nouveaux organismes étudiés ont dû complètement remanier les rôles et les responsabilités de leurs équipes de gestion et comprendre leur nouveau mandat d'élaborer une approche axée sur la population pour ce qui est des problèmes de santé, tout en maintenant leurs activités au jour le jour. Les quatre réseaux de soins de santéétudiés ont travailléà relever ces défis réciproques d'une manière assez différente. L'étude révèle l'importance de trouver un équilibre entre les initiatives consistant à organiser (axées sur les structures) et les initiatives consistant à interpréter les faits (axées sur les stratégies) ; de perfectionner les capacités à interpréter les faits grâce à la création de postes clés d'«interpréteurs de faits», dont les titulaires veilleraient à ce que des activités conceptuelles fassent intervenir les gens travaillant à différents niveaux même lorsque les structures organisationnelles fluctuent continuellement; et enfin de tirer parti des contraintes et influences externes comme autant d'occasions et de ressources pour interpréter et organiser les faits.  相似文献   
144.
145.
146.
Coastal beaches are a source of considerable recreational activity, but are also eroding at a rapid rate. Since beach resources are common property, there is no organized market to determine economic benefits from recreational use. Through a willingness to pay equation for beach use, this article demonstrates how proposed beach renourishment policy can be evaluated within a benefit-cost analysis framework. Benefits are estimated as the incremental willingness to pay per day for a larger beach width which is translated into annualized benefits. Annualize cost of achieving maximum benefits are calculated from a cost function. Given the existing cost of beach renourishment, it was found that all beaches in Florida that are overcrowded (i.e., had less than 112 square feet per person/day) could be renourished at a benefit-cost ratio greater than unity. In Florida, beach renourishment policy for overcrowded beaches yields more economic benefits than costs. However, this technique does not lend itself to policy analyses of uncrowded beaches that are undergoing considerable erosion.  相似文献   
147.
148.
149.
This article identifies and discusses several different conceptions of regulatory reform. It subsequently looks at available evidence on trends in regulatory burdens and on the results of regulatory reform activity undertaken over the past 30 years. Thirdly, it identifies and briefly discusses the range of tools that are typically employed in implementing regulatory reform policies. It then examines some of the regulatory problems that implementation of the reform agenda has itself brought forth. It concludes with some comments which seek to assess the report of the Better Regulation Taskforce in the context of the broad overview of regulatory reform set out in the preceding sections of the article.  相似文献   
150.
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