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   1737篇
  免费   42篇
各国政治   115篇
工人农民   111篇
世界政治   163篇
外交国际关系   93篇
法律   750篇
中国政治   19篇
政治理论   509篇
综合类   19篇
  2021年   16篇
  2020年   28篇
  2019年   31篇
  2018年   37篇
  2017年   43篇
  2016年   50篇
  2015年   20篇
  2014年   49篇
  2013年   288篇
  2012年   34篇
  2011年   40篇
  2010年   37篇
  2009年   30篇
  2008年   43篇
  2007年   50篇
  2006年   66篇
  2005年   48篇
  2004年   60篇
  2003年   39篇
  2002年   44篇
  2001年   31篇
  2000年   45篇
  1999年   29篇
  1998年   22篇
  1997年   26篇
  1996年   35篇
  1995年   23篇
  1994年   28篇
  1993年   23篇
  1992年   21篇
  1991年   27篇
  1990年   26篇
  1989年   24篇
  1988年   29篇
  1987年   20篇
  1986年   22篇
  1985年   20篇
  1984年   36篇
  1983年   25篇
  1982年   22篇
  1981年   23篇
  1980年   24篇
  1979年   14篇
  1978年   16篇
  1977年   10篇
  1976年   16篇
  1975年   9篇
  1974年   13篇
  1973年   10篇
  1972年   12篇
排序方式: 共有1779条查询结果,搜索用时 15 毫秒
191.
This study measured and assessed facial soft tissue depths (FSTDs) in adult female Chinese and New Zealand (NZ) Europeans (Caucasoids). Ultrasound was used to obtain depths at nine landmarks on 108 healthy subjects (51 Chinese, 57 NZ European), erect positioned, of same age group (18–29 years). Height and weight were also recorded. Statistical analysis focused on comparison of tissue depth between the two ancestry groups and the influence of Body Mass Index (BMI) (kg/m2). Results showed mean depth differences at Supra M2 and Infra M2 landmarks significantly greater for Chinese than Caucasoid women for all three BMI Classes (BMI <20, 20 ≤ BMI < 25, 25 ≤ BMI < 30), even BMI <20. For both groups BMI positively correlated with FSTD values at all landmarks except Labrale superius. This study enabled ancestry and BMI influence on FSTDs to be observed and compared for two distinct groups. Results add to knowledge about facial tissue depth variation.  相似文献   
192.
193.
Brief case histories involving incest were presented to police officers, child welfare workers, and community mental health practitioners in a rural area in Canada. Intervention priorities involving “treatment versus punishment” were assessed across the three professional groups for each specific case vignette. Attitudes were assessed on three factors: perpetrator mentally ill rather than criminal, view regarding treatment of victims and mothers, and support for court mandated treatment. Police and community mental health practitioners had significantly different attitudes as to whether perpetrators of child sexual abuse should be viewed more as criminals or as mentally disturbed. Both mental health and child welfare staff differed significantly from police with a less punitive view towards victims and their mothers. All three profressional groups showed no difference in their modest endorsement of the use of mandated treatment by the courts. Gender was not found to influence response to case vignettes.  相似文献   
194.
Mexico's crime-ridden southern frontier has become a veritable third U.S. border, as a constant flow of Central Americans and others cross into Mexico, often en route to the United States. As the number of unlawful migrants surges, their characteristics are changing: recent apprehensions include nationals of Caribbean, Middle Eastern, and Asian nations, and foreigners linked to terrorism are using Mexico as a thoroughfare to the United States. Mexico's immigration department is hindered by a number of factors in stanching this flow, and Mexican officials have only begun to publicly recognize the severity of the problem. Washington, too, must wake up to the security threat posed by Mexico's soft underbelly.  相似文献   
195.
Approaches to genetic testing differ in the research setting and the clinical setting. More data are needed to develop approaches that will best facilitate the use of new genetic tests in the clinical setting, especially settings where genetic testing has not been widely used, such as in primary care. Furthermore, data are needed to establish the clinical utility of new genetic tests in the general practice setting. Natural setting trials are proposed as a strategy to develop this information. While natural setting trials are clinical research studies and will expose participants to some degree of risk, the risks are different, and arguably less than the risks those same individuals would otherwise face if the test went directly into clinical practice. Ultimately, clinical practice and safety of new genetic tests can be improved by adding the evaluation provided by natural setting trials.  相似文献   
196.
197.
Wildland fires constitute a major crisis in American environmental policy, a crisis created by a longstanding policy failure. This article explores the political processes that generated and reinforced this policy failure over time. The concepts of bounded rationality, punctuated equilibria, and self- reinforcing mechanisms are applied to study the evolution of American wildfire policy between 1905 and the present. This study finds that a self-defeating wildfire suppression policy was established in the period 1905 through 1911, and subsequently reinforced for more than five decades. This policy did not include a complementary program to counteract the gradual accumulation of flammable organic materials (fuels) that occurred in many ecosystems when fires were suppressed. The resulting fuel accumulations have greatly increased the risk of damaging, high-intensity wildfires in a range of American wildlands. A combination of fire suppression and fuel reduction programs will be needed to manage this risk in the future.  相似文献   
198.
199.
This paper examines the issue of harmfulness of tax competition commenting on issues like welfare, growth, redistribution, harmonization and individual freedom. A simple game theoretical ap proach is formulated, where for the first time the two players start from unequal initial conditions, thus influencing strategy and outcomes. Next we propose the new criterion of Optimal Tax Area under which the possibility and feasibility of tax harmonization is examined. The policy implication of our paper is that we do not expect harmonization for direct taxes like corporate taxes in the EU in the near future and if so, harmonization of corporate tax rates on low levels. We conclude that both more theoretic research and empirical evidence are needed before we can answer with certainty whether tax competition is harmful or not. classification A1 . D6 . H0  相似文献   
200.
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