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   85632篇
  免费   3577篇
  国内免费   41篇
  2020年   1050篇
  2019年   1258篇
  2018年   1808篇
  2017年   1868篇
  2016年   1881篇
  2015年   1354篇
  2014年   1567篇
  2013年   7494篇
  2012年   2965篇
  2011年   3060篇
  2010年   1922篇
  2009年   1845篇
  2008年   2693篇
  2007年   2528篇
  2006年   2340篇
  2005年   1973篇
  2004年   1880篇
  2003年   1853篇
  2002年   1743篇
  2001年   2774篇
  2000年   2675篇
  1999年   1968篇
  1998年   942篇
  1997年   790篇
  1996年   861篇
  1995年   779篇
  1994年   780篇
  1993年   761篇
  1992年   1639篇
  1991年   1528篇
  1990年   1505篇
  1989年   1421篇
  1988年   1392篇
  1987年   1312篇
  1986年   1270篇
  1985年   1375篇
  1984年   1108篇
  1983年   927篇
  1979年   1129篇
  1978年   847篇
  1975年   942篇
  1974年   1033篇
  1973年   1102篇
  1972年   924篇
  1971年   825篇
  1970年   736篇
  1969年   747篇
  1968年   937篇
  1967年   804篇
  1966年   838篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
Twenty-eight boys and 28 girls at each of the Piagetian preoperational, concrete operational, and formal operational cognitive stages were given an interview focusing on their concepts of family. Half of each group were from intact families, and half were from divorced families. Interviews were scored for two structural aspects of the concept of family: conceptual level, and use of dimensions that structure the concept. The complexity of children's concepts was strongly related to cognitive stage and, to a lesser degree, to sex. Frequency of use of concept dimensions was strongly affected by general developmental level, though not specifically cognitive stage, and by intactness of family, but to a lesser degree by sex. Specific information is provided on the effect of these factors on perceptions of family composition, parental roles, and breadth of family activities.  相似文献   
972.
In an attempt to replicate the findings reported in this Journal by Weyant and Smith (1987), members or recent donors to a Canadian civil liberties organization were asked to donate money under one of three conditions: (a) In the control condition, they were simply asked for a donation; (b) in the “smaller request” condition, they were asked to make a donation, but amounts of Canadian $30 to $100 were suggested; and (c) in the “larger request” condition, amounts of $50 to $250 were suggested. Unlike the Weyant and Smith studies, we found no difference in the proportion of respondents making a donation, but significant differences in the size of the donations made by those making donations. In our study, the most effective way of getting large donations was to ask for a large amount. It was suggested that the most likely explanations for the differences in the results of the two studies were the following: First, our target population were previous donors to the organization, whereas those in the Weyant and Smith studies were not likely to have been. Previous research suggests that those who had been donors previously are influenced, positively, by requests for a specific large donation, whereas those not previously approached are, if anything, negatively influenced. Second, our “larger request” appears to be within a plausible range for donations, whereas the larger request in the Weyant and Smith study may have been seen as being outside of the plausible range. In any case, however, we would recommend caution in drawing a conclusion about the most effective request size to encourage people to donate money to charity.  相似文献   
973.
The relationship of knowledge and attitudes to adolescent contraceptive efficacy was investigated in a multivariate study, with demographic and sexual history variables covaried. Subjects were unmarried, sexually active 15- to 19-year-old women. Two studies were conducted: one using a large and representative sample and the second using a smaller, high socioeconomic status sample that is more typical of samples generally used in earlier research. Subjects were classified as effective, ineffective, or nonusers of contraception, based on both frequency of use and effectiveness of the method(s) they used. Two discriminant function analyses were performed to determine (a) whether knowledge and attitudes contributed to discrimination among the groups over and above discrimination attributable to demographic and sexual history variables, and (b) which variables distinguished ineffective users from both other groups. The results of both studies indicate that attitudes, particularly attitudes toward contraception, are strong predictors of patterns of contraceptive use. Ineffective users were distinguished from nonusers by their greater knowledge of contraception, and from both other groups by their greater sexual activity and more positive attitudes toward intercourse. The discussion focuses on the theoretical implications of the results, the usefulness of the effective/ineffective/nonuser categorization, and applications of these findings to design of interventions.  相似文献   
974.
There is increased evidence that infants who receive poor quality social stimulation from their primary caregiver are at risk for later developmental difficulties. This paper describes a preventive intervention for mother-infant dyads exhibiting impaired patterns of social interaction. An impaired relationship with the primary caregiver has been found to be associated with social and emotional deficits in early childhood as well as with significant psychopathology in adulthood. The intervention consisted of group treatment of mothers and their infants. Each group session has 4 subsections which, together, were directed towards improving the mothers' ability to relate in a stimulating and nurturant manner to their children. Types of intervention included didactic instruction, modeling, and interpretation of the infant's behavior. Qualitative data suggested that the group intervention has positive effects on the mother-infant dyads.  相似文献   
975.
976.
“Anchoring” results from insufficient adjustment up or down from an original— often arbitrary—starting value. Six sets of surveys were designed to assess the effects of anchoring on subjective likelihood estimates of a nuclear war. Based on responses from 1600 students, results indicated that: (a) likelihood estimates were strongly susceptible to anchoring; (b) neither likelihood estimates nor the effects of anchoring were significantly influenced by the ease with which respondents could imagine a nuclear war (outcome availability), by instructions to list the most likely path to nuclear war (path availability), or by casting the problem in terms of the avoidance, rather than the occurrence, of nuclear war; (c) the effects of anchoring extended to estimates concerning the efficacy of strategic defenses; and (d) likelihood estimates were affected by anchoring even after correcting for social demand biases. In estimating the likelihood of nuclear war and otherwise attempting to “think the unthinkable”, many students responded in a manner consistent with denial; the paper concludes with a discussion of these individuals.  相似文献   
977.
The results of a study of the Wilderness Therapy Program involving 23 adolescents in outpatient counseling are presented. Data were collected before and after four trips on measures of locus of control, behavioral symptoms, self-efficacy, self-esteem, and a number of measures designed specifically for this program. Following a one and one-half to two week backpacking trip that included daily therapy, significant change was found for locus of control, self-esteem and symptom reduction. Positive changes were noted on the other measures as well. Future directions and social work implications were discussed.  相似文献   
978.
In this paper I attempt to show that subjectivity, as an input to the creative core of physics, is a misunderstood, but crucial factor. Utilizing Rapaport's fundamental paper, Principles Underlying Projective Techniques which identifies the determinants of the projective technique as: 1. lack of organization, 2. undifferentiation, 3. closeness to the core of the personality, and 4. the meaning of the stimulus being unknown to the subject, a link is suggested to quantum mechanics. It is further suggested the revolutionary nature of quantum mechanics satisfies the projective criterion of the material being unorganized or unfamiliar so that the function of organization can become predominant (Rapaport 1942, p. 93).  相似文献   
979.
Two studies were conducted examining the stimulus-control effects of conventional traffic signs as prompts for motor vehicle driver safety belt use. Following pilot research which suggested that a traffic sign reading “Fasten Safety Belt” posted at a parking lot exit was effective in producing small increases in safety belt use, Study I demonstrated the superiority of having human prompters display such signs compared to simply posting the signs. Study II replicated the findings of Study I and found that posted signs became more effective in prompting safety belt use if simple posting was preceded by a period involving human prompters who displayed the signs. The results bear upon the development of more effective use of traffic signs in promoting safety belt use and in viewing such use as an instance of rule-governed behavior.  相似文献   
980.
Previous researchers using between-subjects comparisons have found eyewitness confidence and accuracy to be only negligibly correlated. In this study, we examined the predictive power of confidence in within-subject terms. Ninety-six subjects answered, and made confidence ratings for, a series of questions about a crime they witnessed. The average between-subjects and within-subject accuracy-confidence correlations were comparably low: r = .14 (p less than .001) and r = .17 (p less than .001), respectively. Confidence is neither a useful predictor of the accuracy of a particular witness nor of the accuracy of particular statements made by the same witness. Another possible predictor of accuracy, response latency, correlated only negligibly with accuracy (r = -.09 within subjects), but more strongly with confidence (r = -.27 within subjects). This pattern was obtained for both between-subjects and within-subject comparisons. The theoretical and practical implications of these results 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