全文获取类型
收费全文 | 165313篇 |
免费 | 7602篇 |
国内免费 | 156篇 |
出版年
2021年 | 1481篇 |
2020年 | 2762篇 |
2019年 | 3424篇 |
2018年 | 3405篇 |
2017年 | 3834篇 |
2016年 | 4546篇 |
2015年 | 3904篇 |
2014年 | 4784篇 |
2013年 | 23381篇 |
2012年 | 4281篇 |
2011年 | 3310篇 |
2010年 | 3763篇 |
2009年 | 4689篇 |
2008年 | 3563篇 |
2007年 | 3122篇 |
2006年 | 3801篇 |
2005年 | 3795篇 |
2004年 | 3316篇 |
2003年 | 2952篇 |
2002年 | 2734篇 |
2001年 | 2884篇 |
2000年 | 2794篇 |
1999年 | 2904篇 |
1998年 | 2802篇 |
1997年 | 2628篇 |
1996年 | 2560篇 |
1995年 | 2390篇 |
1994年 | 2363篇 |
1993年 | 2306篇 |
1992年 | 2379篇 |
1991年 | 2263篇 |
1990年 | 2095篇 |
1989年 | 2039篇 |
1988年 | 2014篇 |
1987年 | 2034篇 |
1986年 | 2022篇 |
1985年 | 2240篇 |
1984年 | 2383篇 |
1983年 | 2210篇 |
1982年 | 2333篇 |
1981年 | 2302篇 |
1980年 | 2156篇 |
1979年 | 2055篇 |
1978年 | 2115篇 |
1977年 | 2087篇 |
1976年 | 1870篇 |
1975年 | 1885篇 |
1974年 | 1931篇 |
1973年 | 1800篇 |
1972年 | 1414篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
921.
922.
Caryn L. Carlson Ph.D. William E. Pelham Jr. Richard Milich Joanne Dixon 《Journal of abnormal child psychology》1992,20(2):213-232
Twenty-four boys with attention deficit-hyperactivity disorder (ADHD) participating in an intensive summer treatment program each received b.i.d. placebo and two doses of methylphenidate (MPH, 0.3 mg/kg and 0.6 mg/kg) crossed with two classroom settings: a behavior modification classroom including a token economy system, time out and daily home report card, and a regular classroom setting not using these procedures. Dependent variables included classroom observations of on-task and disruptive behavior, academic work completion and accuracy, and daily self-ratings of performance. Both MPH and behavior modification alone significantly improved children's classroom behavior, but only MPH improved children's academic productivity and accuracy. Singly, behavior therapy and 0.3 mg/kg PMH produced roughly equivalent improvements in classroom behavior. Further, the combination of behavior therapy and 0.3 mg/kg MPH resulted in maximal behavioral improvements, which were nearly identical to those obtained with 0.6 mg/kg MPH alone.The authors gratefully acknowledge the assistance of Patricia Donovan, Michelle Berry, Mary Ingram, Patricia Wells, Beth Gnagy, Karen Greenslade, Mary Hamilton, and the entire staff of the Western Psychiatric Institute and Clinic ADHD Summer Treatment Program. 相似文献
923.
M C Rodriguez-Perez F de Vicente-Perez G Gomez-Jarabo Garcia 《Behavioral and neural biology》1992,58(3):165-170
The use of neurological tests in various states of undernutrition has confirmed the presence of delays in reflex ontogeny. Glucocorticoid administration in conditions of normal nutrition produces diminished growth and alterations in brain development similar to those observed in malnutrition, but there is not enough evidence about its effect on reflex development. In addition, some facts lead us to think that the use of permissive doses of these hormones during gestation could alleviate some of the effects of protein malnutrition on the development of pups. In the present study the ages at which certain reflexes appeared in the offspring of Wistar rats (Rattus norvegicus) fed a 20% (N) or 10% (M) protein diet from a week before conception to the end of lactation were observed. Each dietary group was subdivided into two: mothers receiving a daily injection during gestation either of a 0.9% NaCl (S) solution or of a 0.5 mg/100 g weight hydrocortisone acetate (C) solution. Results showed that the NS group of pups generally presented earlier ages of appearance of the variables under study than the remaining groups. Pups of the NC group presented delays in the age of appearance of reflexes. Finally, protein malnutrition delayed the appearance of reflexes and this effect seemed to be attenuated by treatment with hydrocortisone. Thus, hydrocortisone administration in protein malnutrition conditions seems to be beneficial although the results are harmful when administered under normal nutritional conditions. 相似文献
924.
Fifteen rats performed in a standard radial-arm maze task (Experiment 1) and in a modified task with a set of forced choices and a 15-min retention interval prior to completion of the maze (Experiment 2). In addition to the standard measure of choice in the radial-arm maze, orientation toward arms was measured and considered to constitute go-no-go "microchoice" decisions. Rats investigated but rejected many arms. A model of choice was developed in which it was assumed that choice decisions about arms were made independently and that microchoices were not selectively guided toward baited arms. The model performed nearly as well as the rats. These results place important limitations on the theory that choice behavior in the radial-arm maze is guided by a cognitive map. 相似文献
925.
926.
A multivariate hierarchical model of specific cognitive abilities was fitted to data from 7-year-old adopted and nonadopted sibling pairs in the Colorado Adoption Project in order to assess differential genetic influence on specific mental abilities. Model fitting results and Schmid-Leiman (Schmid & Leiman, 1957) transformations reveal significant heritable variation for verbal, spatial, and memory factors independent of general cognitive ability for the eight ability tests examined. In contrast, environmental influences are primarily measure-specific. The results suggest genetic effects in middle childhood that differentially influence mental ability scores. 相似文献
927.
PATRICIA M. BERLINER 《Counseling and values》1992,37(1):2-14
A feminist psychospiritual model of therapy that can be used in working with clients who value the spiritual dimension in their lives is offered. The history, philosophy, and work of Women for a New World, a multidisciplinary team of women representing the areas of psychology, religious education, and the arts is presented. Using examples drawn from the developmental history of our retreat-workshop paradigm and from some of our programs, including a weekend retreat for women and a day of reflection for persons affected by AIDS (including family and friends of those with AIDS), the metaphor of therapy as soul healing is developed. 相似文献
928.
MARK J. MILLER 《Counseling and values》1992,37(1):25-31
Surprisingly little has been written in the counseling journals on the topic of lying: that is, why some clients consciously choose to be either dishonest with their counselors or deliberately hold back (i.e., keep secrets) important information from their counselors. This article discusses the dynamics of lying and offers suggestions to counselors on how to work with clients who lie. 相似文献
929.
930.
A model of cognitive and affective antecedents and consequences of personal goals, which integrates constructs from social-cognitive and attribution theories, was examined. Data were gathered before and after course examinations in a large university class. Hierarchical and moderated regression analyses supported the model indicating that (1) relationships between self-efficacy, goals, and performance were positive during repeated trials over 4 1/2 months in a naturally occurring setting; (2) the stability dimension of causal attributions moderated the relationship between goal-performance discrepancies and self-efficacy; and (3) the locus of causality dimension of causal attributions moderated the relationship between goal-performance discrepancies and affective responses.We thank Susan Ashford, Jim Austin, Donald Fedor, Ruth Kanfer, Edwin Locke, Paul Nystrom, Donna Randall, Christina Shalley, Masoud Yasai-Ardekani and two anonymous reviewers for their helpful comments on earlier versions of this article. We also thank Eric Dietenberger for his help with graphics. 相似文献