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   17612篇
  免费   702篇
  国内免费   13篇
  18327篇
  2021年   152篇
  2020年   276篇
  2019年   318篇
  2018年   469篇
  2017年   451篇
  2016年   465篇
  2015年   334篇
  2014年   409篇
  2013年   1840篇
  2012年   737篇
  2011年   760篇
  2010年   458篇
  2009年   505篇
  2008年   659篇
  2007年   661篇
  2006年   657篇
  2005年   600篇
  2004年   551篇
  2003年   559篇
  2002年   541篇
  2001年   372篇
  2000年   313篇
  1999年   295篇
  1998年   230篇
  1997年   247篇
  1996年   232篇
  1995年   197篇
  1994年   186篇
  1993年   194篇
  1992年   201篇
  1991年   220篇
  1990年   194篇
  1989年   176篇
  1988年   150篇
  1987年   173篇
  1986年   177篇
  1985年   219篇
  1984年   216篇
  1983年   183篇
  1982年   179篇
  1981年   180篇
  1980年   156篇
  1979年   165篇
  1978年   172篇
  1977年   156篇
  1976年   145篇
  1975年   156篇
  1974年   164篇
  1973年   140篇
  1972年   105篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
The present study tested gender as a moderator of the relationship between race-related stress and mental health symptoms among African American adults. Because African American women are exposed to stressors associated with race and gender, we hypothesized that African American women would have higher levels of race-related stress and more severe mental health outcomes related to experiences of race-related stress compared to African American men. Multivariate analyses revealed that African American men had higher stress appraisals for institutional racism than did women. No significant gender differences were found for cultural and individual racism. Moderated regression analyses revealed that increases in stress appraisals for individual racism were associated with increases in anxiety and obsessive-compulsive symptoms for African American women. Race-related stress had no significant effects on mental health symptoms for African American men. The findings suggest that gender is an important factor in determining the impact of race-related stress on mental health.  相似文献   
2.
Rats received Pavlovian conditioning in which food was signalled by a visual stimulus, A+, an auditory stimulus, B+, and a compound composed of different visual and auditory stimuli, CD+. Test trials were then given with the compound AB. Experiments 1 and 2A revealed stronger responding during AB than during CD. In Experiment 2B, there was no evidence of a summation of responding during AB when A+ B+ training was conducted in the absence of CD+ trials. A further failure to observe abnormally strong responding during ABwas found in Experiment 3 for which the training trials with A+ B+ CD+ were accompanied by trials in which C and D were separately paired with food. The results are explained in terms of a configural theory of conditioning, which assumes that responding during a compound is determined by generalization from its components, as well as from other compounds to which it is similar.  相似文献   
3.
Most arguments against active euthanasia, as do most arguments in applied ethics generally, take place within the framework of what can broadly be referred to as a modern, as opposed to an ancient, approach to moral theory. In this paper, I argue that this fact works to the disadvantage of opponents of active euthanasia, and that if there is a successful argument against active euthanasia, it will be of the latter sort. In Part I, I attempt to clarify thedistinction between modern and ancient approaches with which I am concerned. In Part II, I attempt to show that any argument against active euthanasia that is of the first sort is bound to fail. In Part III, I propose an argument against active euthanasia of the second sort that I believe has a better chance for success. In Part IV, I consider some objections that can be raised against this argument and attempt to show how they can be overcome.  相似文献   
4.
5.
6.
7.
8.
The authors used recursive partitioning methods to identify combinations of baseline characteristics that predict 2-year physical activity success in each of 3 physical activity interventions delivered in the multisite Activity Counseling Trial. The sample consisted of 874 initially sedentary primary care patients, ages 35-75 years, who were at risk for cardiovascular disease. Predictors of 2-year success were specific to each intervention and represented a range of domains, including physiological, demographic, psychosocial, health-related, and environmental variables. The results indicate how specific patient subgroups (e.g., obese, unfit individuals; high-income individuals in stable health) may respond differently to varying levels and amounts of professional assistance and support. The methods used provide a practical first step toward identifying clinically meaningful patient subgroups for further systematic investigation.  相似文献   
9.
10.
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