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   23854篇
  免费   858篇
  国内免费   12篇
  24724篇
  2020年   240篇
  2019年   256篇
  2018年   397篇
  2017年   434篇
  2016年   434篇
  2015年   275篇
  2014年   366篇
  2013年   1831篇
  2012年   693篇
  2011年   755篇
  2010年   459篇
  2009年   432篇
  2008年   641篇
  2007年   608篇
  2006年   558篇
  2005年   495篇
  2004年   484篇
  2003年   454篇
  2002年   496篇
  2001年   743篇
  2000年   756篇
  1999年   564篇
  1998年   270篇
  1997年   228篇
  1992年   453篇
  1991年   415篇
  1990年   451篇
  1989年   422篇
  1988年   404篇
  1987年   402篇
  1986年   413篇
  1985年   436篇
  1984年   344篇
  1983年   308篇
  1982年   244篇
  1981年   223篇
  1979年   394篇
  1978年   282篇
  1977年   251篇
  1976年   224篇
  1975年   346篇
  1974年   380篇
  1973年   352篇
  1972年   331篇
  1971年   291篇
  1970年   262篇
  1969年   323篇
  1968年   361篇
  1967年   324篇
  1966年   325篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
951.
In laboratory strains of mice, reproductive maturation is influenced by both the fetal and the peripubertal social environments experienced by females. Intrauterine position (IUP) for female fetuses is identified by the number of adjacent males; where 0M have zero, 1M have one, and 2M have two male neighbors. We sought to confirm, using wild-type female house mice (Mus musculus), the previous finding in the CF-1 strain of laboratory mouse that males prefer 0M over 2M females as mates. We recorded the age at first reproduction for females of known IUP housed either individually with a male or in a group of 6 females and a male. In neither housing condition were there significant differences in age of first reproduction among females of different IUPs, but 0M females that were group housed had perforate vaginas at an earlier age than other group-housed females. Mean (+/- SE) age at first reproduction was 58.1 (+/- 3.3) for paired and 126.6 (+/- 5.1) for group-housed females. The reproductive suppression observed in the grouped females was probably due to the interaction of inhibitory urinary chemosignals, low body weights, and female dominance hierarchies.  相似文献   
952.
Marketing claims of effectiveness in improving academic achievement through the use of commercially prepared subliminal audiotapes were investigated. Students enrolled in a career development class were randomly assigned to an active treatment group (n=25), an inactive treatment group (n=26), or a control group (n=22). Participants in the treatment group listened to tapes with subliminal affirmations masked by ocean waves. The inactive treatment group listened to placebo tapes with ocean waves but no subliminal messages. Dependent variables used were final examination scores from the class and current semester grade point average. No treatment differences on either dependent measure were found. The implications of these findings are discussed.  相似文献   
953.
In Experiment 1 young and elderly subjects either recalled or repeated after every block of 4 actions, whereas control subjects received neither interpolated short-term recall nor action repetition. On a later long-term memory test, experimental subjects, regardless of age or condition, recalled slightly more actions than control subjects. In Experiment 2 young adult and elderly subjects received 12 short-term memory trials in which 2 actions were performed on each trial, but only 1 was cued for recall after a brief retention interval filled with a distracting activity. On a later long-term memory test for the actions performed on the short-term trials, both young and elderly subjects recalled significantly more previously cued than noncued actions. The Age X Cuing Condition interaction was negligible. Prior retrieval of actions appears to enhance later recall regardless of age but seemingly only when prior retrieval requires considerable cognitive effort (as in Experiment 2).  相似文献   
954.
In this research, older adults (N = 150) hospitalized for major depression and their wife, husband, daughter, or son caregivers were interviewed. The primary purpose of the research was to evaluate the ability of caregiver background characteristics, patient illness characteristics, caregiver coping, and strategies for managing the patient at home to predict caregiver adjustment. Among the caregiver characteristics, being in functional health, being male, and being a spouse caregiver were associated with better adjustment. Husbands evidenced the best adaptation to caregiving and daughters the poorest. Patient illness characteristics were not related to caregiver adjustment. Coping with caregiving stresses by using tension reduction and deliberate effort behaviors and managing the patient with criticism and guidance were related to poorer caregiver adjustment.  相似文献   
955.
A longitudinal organizational field study examined work satisfaction and employee growth coping as joint predictors of turnover. Three employee categories were examined: 1) No Turnover, 2) turnover within the same occupational field (Intraoccupational Turnover), and 3) turnover to a new occupational field (Interoccupational Turnover). Work satisfaction was moderate in the first two groups and low in the third group. As predicted, a specific strategy of employee coping, growth, was lowest in the first group, moderate in the second group, and highest in the third group. Through the use of linear discriminant analysis, 66.4% of the employees were correctly classified into No Turnover, Intraoccupational Turnover, and Interoccupational Turnover groups based only on information regarding work satisfaction and growth coping. The first squared canonical correlation was found to equal .30, far surpassing the modest work satisfaction/turnover correlations found in all previous studies.The authors wish to thank the two anonymous reviewers for their thoughtful comments.  相似文献   
956.
957.
Thirty-five undergraduates participated in an outcome study which compared the results of enrollment in an RET seminar with enrollment in a seminar on another psychotherapy topic, Humanistic Psychology, and two seminars which lacked a psychotherapeutic orientation: Social Development and Extra Sensory Perception. RET instruction failed to decrease irrationality significantly. However, students who received RET instruction had significantly higher perceived self-efficacy than did those in the two nontherapy oriented seminars. There was a significant, inverse relationship between academic achievement (grade point average) and irrational beliefs about need for comfort, need for approval, awfulizing, and low frustration tolerance. Perceived self-efficacy was significantly and positively associated with high academic achievement. Superior students were significantly less likely than their peers to awfulize or exhibit low frustration tolerance; the poorest students were the least likely group to perceive themselves as effective. The implications of these findings for educators and counselors were addressed.A fellow in Rational-Emotive Therapy, Naomi McCormick, Ph.D. is a professor and William Tooke, Ph.D. is an assistant professor at the State University of New York-Plattsburgh. An earlier version of this article was presented at the World Congress on Mental Health Counseling: A 35th Anniversary Celebration of Rational-Emotive Therapy, Keystone, Colorado: June 13–16, 1990. The authors are grateful to H. Morlock for his methodological insights and thank G. Brannigan, N. Smith, and P. Jarvis for assisting in data collection. Special thanks go to H. Rock for providing information on students from the college's Office of Institutional Research.  相似文献   
958.
959.
The following two articles offer a glimpse at current experimental psychology in the Soviet Union, normally screened from the English-speaking world by all but impenetrable language barriers. The accompanying Commentary by Tarow Indow helps place these contributions in the framework of contemporary work on the psychophysics of color perception.   Abstract —
Fifteen normal trichromatic subjects, two protanopes, and two deuteranopes judged pairs of successively presented foveal color stimuli. Multidimensional scaling of the data yielded estimates of a three-dimensional space with axes interpreted as red–green, blue-yellow, and white-black. For color-deficient subjects, the average radius of the space differed from that of normals, being smaller for the protanopes and larger for the deuteranopes. For both types of color deficiency, the blue-yellow axis was stretched relative to the red-green, more strongly in the protanopes. The findings are taken to support the generality of a "spherical" model.  相似文献   
960.
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