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   26320篇
  免费   1130篇
  国内免费   17篇
  2021年   227篇
  2020年   374篇
  2019年   365篇
  2018年   652篇
  2017年   574篇
  2016年   596篇
  2015年   372篇
  2014年   499篇
  2013年   2172篇
  2012年   986篇
  2011年   1033篇
  2010年   579篇
  2009年   585篇
  2008年   866篇
  2007年   814篇
  2006年   750篇
  2005年   664篇
  2004年   569篇
  2003年   563篇
  2002年   523篇
  2001年   846篇
  2000年   859篇
  1999年   620篇
  1998年   258篇
  1997年   229篇
  1996年   211篇
  1992年   511篇
  1991年   437篇
  1990年   508篇
  1989年   430篇
  1988年   405篇
  1987年   379篇
  1986年   393篇
  1985年   451篇
  1984年   353篇
  1983年   296篇
  1982年   226篇
  1979年   334篇
  1978年   265篇
  1976年   210篇
  1975年   304篇
  1974年   351篇
  1973年   356篇
  1972年   280篇
  1971年   251篇
  1970年   216篇
  1969年   234篇
  1968年   298篇
  1967年   257篇
  1966年   281篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
961.
The purpose of the present research was to propose and test a motivational process model of academic achievement. The model posits that parental, teachers, and school administration support for students' autonomy positively influences students' perceived school competence and autonomy. In turn, perceived school competence and autonomy affect positively self-determined school motivation which in turn influences academic achievement. Two studies using a prospective design tested the adequacy of the model. In Study I, participants were 1,623 ninth-grade students. Results from structural equation modeling supported the motivational model. Participants in Study 2 were 1,098 tenth-grade students. Results from this study corroborated those of Study 1 controlling for students' prior achievement in the ninth grade. The role of self-determinod school motivation in academic achievement is discussed and avenues for future research are considered. This research is part of a larger project that is being funded by grants from the William and Flora Hewlett Foundation; the San Francisco Foundation; the Robert Wood Johnson Foundation; the Danforth Foundation; the Smart Foundations; the Pew Charitable Trusts; the John D. and Catherine T. MacArthur Foundation; the Annenberg Foundation; Spunk Fund, Inc.; the DeWitt Wallace-Reader's Digest Fund, Inc.; Louise and Claude Rosenberg; and the Center for Substance Abuse Prevention, U.S. Department of Health and Human Services. The views expressed in the paper are those of the authors and not necessarily of the funders. We are grateful to the many educators, students, and colleagues who cooperated with us on this project and to several anonymous reviewers who provided helpful suggestions.  相似文献   
962.
An injection olfactometer for human psychophysical experiments is described. The olfactometer is capable of presenting, either mono- or birhinally, single odorants and binary mixtures. The pulse form of the olfactory stimulus at the exit of the olfactometer approaches a rectangular form, which makes the olfactometer well suited for olfactory reaction time measurements. Since stimulation periods are independent of the subject’s inhalation, time-intensity measurements over prolonged periods of time are possible as well. In the second part of this paper, a new technique is described for the measurement of the stimulus pulse form at the exit of the olfactometer.  相似文献   
963.
We investigated the ability of subjects to discriminate sugars with a whole-mouth forced-choice paradigm, in which a standard solution was compared with a test solution of varied concentration. Discrimination probabilities were U-shaped functions of test concentration: for 6 subjects and pairwise combinations of fructose, glucose, and sucrose, discriminability always declined to chance over a narrow range of test concentrations. At concentrations ≦ 100 mM, maltose was indiscriminable from fructose but discriminable at higher concentrations for 4 subjects. By analogy with themonochromacy of night vision, whereby any two lights are indiscriminable when their relative intensities are suitably adjusted, we call the gustatory indiscriminability of these sugarsmonogeusia. The simplest account of monogeusia is that all information about the indiscriminable sugars is represented by a single neural signal that varies only in magnitude. The discriminability of maltose from the other sugars at higher concentrations is consistent with the hypothesis that maltose also activates a second gustatory code.  相似文献   
964.
During linear translation through a stationary environment, the pattern of optical flow generated on each retina is symmetrical when the head is aligned with the heading, but during lateral gaze the optical flow is asymmetric. We assessed whether human subjects could use the magnitude of this asymmetry to determine the direction of heading during passive translation through a 3-D environment. When allowed to move their heads in order to look in the direction of self-motion, subjects indicated their heading precisely and accurately. When the head was locked in alignment with the misaligned body, and gaze adjustments were not allowed, responses were quite precise, but showed a large bias which increased with increasing heading angle.  相似文献   
965.
Koss  Mary P.  Leonard  Kenneth E.  Beezley  Dana A.  Oros  Cheryl J. 《Sex roles》1985,12(9-10):981-992
Sex Roles - Rape is an underreported and underconvicted crime. Therefore, many highly sexually aggressive men are missed by research employing judicial identification for sample selection. The...  相似文献   
966.
The purpose of this paper is to review the necessary components of a comprehensive group therapy program. The balancing between the didactic and the experiential portions, and an analysis of the selection criteria, along with the rationale for a particular sequencing of elements in the curriculum, are discussed. A line between supervision and personal therapy is drawn. The author describes the milieu necessary for a successful training program to evolve and makes suggestions for improvements. The various experiential aspects of training are presented and critically evaluated. The training situation is examined from the point of view of the faculty, the trainee and the patients involved. The author marshalls evidence indicating that personal group psychotherapy in a patient group is the preferred form for most trainees for the experiential part of the program. The paper concludes that the sharing and cohesiveness of training philosophies and methods by the faculty is a prerequisite to the success of any training program.  相似文献   
967.
The current investigation examined the degree to which judges' ratings of skill, anxiety, and attractiveness are influenced by the responsivity of the confederate. High-, medium-, and low-skilled subject-pool groupings, as well as self-referred clinical groups, were exposed to either a moderately or a minimally responsive confederate. Results indicated that subjects were rated as more skillful when interacting with a moderately responsive confederate than when interacting with a minimally responsive confederate. Further, there was a groups × condition interaction for anxiety ratings such that both the high- and the medium-skilled groups appeared more anxious under the minimal condition, whereas the low-skilled and self-referred groups did not. Self-referred subjects received significantly lower attractiveness ratings than did the high- or medium-skilled groups. Implications of these results and future directions for research are discussed.This research is based on a M.S. thesis carried out by the first author under direction of the second author.  相似文献   
968.
The present study investigated the validity of an inpatient pain behavior rating scale modified for outpatient use. A series of 43 consecutive outpatients referred for evaluation of chronic pain was examined using the Pain Behavior Scale (PBS) and other psychometric instruments. Analyses revealed significantly higher Pain Behavior Scale scores for low back and multiple pain-site groups. The results also indicated a high degree of internal consistency of the scale. A multiple regression analysis, predicting observed pain behavior from reported pain behavior, indicated that decreased activity accounted for 32% of the variance in the PBS score. A similar regression for pain experience found that the pain level and the sensory scale score on the McGill Pain Questionnaire accounted for 39% of the PBS variance. Psychological characteristics including disease conviction, self-control, depression, and anxiety explained 45% of the variability in the PBS score. Thus, the scale is related to pain intensity, interference with activities, and a variety of psychological characteristics. The scale provides a measure of observable pain behavior that is also relatively independent of these clinical data sources. The Pain Behavior Scale as modified for outpatient use provides a brief index of pain behavior with potential use in the comprehensive evaluation of the pain patient.  相似文献   
969.
970.
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