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   57808篇
  免费   1422篇
  国内免费   25篇
  2020年   443篇
  2019年   498篇
  2018年   3965篇
  2017年   3339篇
  2016年   2868篇
  2015年   739篇
  2014年   726篇
  2013年   3349篇
  2012年   1715篇
  2011年   3537篇
  2010年   3162篇
  2009年   2220篇
  2008年   2744篇
  2007年   3141篇
  2006年   1043篇
  2005年   1157篇
  2004年   1055篇
  2003年   1019篇
  2002年   994篇
  2001年   950篇
  2000年   928篇
  1999年   690篇
  1998年   443篇
  1997年   443篇
  1996年   378篇
  1992年   589篇
  1991年   596篇
  1990年   591篇
  1989年   559篇
  1988年   486篇
  1987年   521篇
  1986年   559篇
  1985年   623篇
  1984年   541篇
  1983年   492篇
  1982年   380篇
  1981年   432篇
  1979年   535篇
  1978年   416篇
  1977年   383篇
  1975年   487篇
  1974年   550篇
  1973年   559篇
  1972年   452篇
  1971年   443篇
  1970年   407篇
  1969年   435篇
  1968年   515篇
  1967年   493篇
  1966年   473篇
排序方式: 共有10000条查询结果,搜索用时 31 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.
Serial pattern learning was investigated in a variation of the task introduced by Nissen and Bullemer (1987). We presented an asterisk at 1 of 4 spatial locations on each trial, and Ss either responded with a keypress or observed the event. The first 4 blocks contained 10 repetitions of a 10- or 16-element pattern, and the 5th block contained a random sequence. The difference in response time on the 5th random block and the previous patterned block served as an indirect measure of pattern learning. A direct measure was obtained in a final test block in which Ss predicted the next asterisk position. Equivalent learning occurred for responding and observing with indirect measures, but observation was superior with direct measures. These findings indicate that knowledge of serial order can develop through simple perceptual experience, and this is more available to deliberate recall than is knowledge acquired while responding.  相似文献   
4.
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   
5.
6.
7.
Adult-child interactions during stressful medical procedures were investigated in 43 pediatric patients videotaped during a venipuncture procedure in the course of cancer treatment. Relations among six adult behavior categories (explain, distract, command to engage in coping behavior, give control to the child, praise, and criticize/threat/bargain) and three child behavior categories (momentary distress, cry/scream, and cope) were examined using correlational and sequential analysis. Results indicated that adult distraction resulted in increased child coping and reduced momentary distress and crying. Adult explanations, although a likely response to child distress and crying, did not result in a reduction of these behaviors. Attempts to give the child control reduced child crying. Implications for clinical interventions during painful medical procedures are discussed.  相似文献   
8.
Durkheim's influential book, Suicide, provides general (economic) anomie, conjugal anomie, and sex-role convergence explanations of changes in suicide rates under conditions of social change. We used trend analyses of American suicide rates and female/male suicide ratios from 1950 to 1984 and the regression of the ratios on female educational attainment, white female labor force participation, white fertility rates, and divorce rates to examine these explanations. The general anomie explanation of female suicide trends is supported for the middle-aged (30 to 54 years) but not for the young (10 to 30 years) or the elderly (55 to 74 years). The conjugal anomie proposition is at best supported for age groups between 15 and 44 when general anomie is not pronounced. The role convergence explanation is rejected for all 13 5-year-age-groups. General anomie may not be a viable explanation of suicide trends for groups actively supporting relevant social changes or not yet tradition-bound or for groups whose retirement status reduces the importance of some social changes.  相似文献   
9.
10.
We describe three experiments testing treatments to promote the performance of health-protective dental behaviors. Subjects included 55 women from an introductory psychology course (Experiment 1), 45 men and women (Experiment 2), and 81 older-than-average students identified as at risk for gum disease (Experiment 3). The interventions, derived from social cognitive theory, included health education, skills training, and self-monitoring. In each study, we examined the contribution of additional treatment components, including social support (Experiment 1), intensive contact (Experiment 2), and flexible goal setting (Experiment 3). Across experiments, the behavioral results were remarkably similar: Subjects exhibited excellent adherence while in the study but, at follow-up, reported behavior that differed little from baseline. We discuss parallels between attempts to promote health-protective dental behaviors and other health-promotion programs, and we describe different perspectives from which to address the problem of creating healthy habits.  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