全文获取类型
收费全文 | 2003篇 |
免费 | 279篇 |
国内免费 | 134篇 |
专业分类
2416篇 |
出版年
2023年 | 29篇 |
2022年 | 34篇 |
2021年 | 50篇 |
2020年 | 88篇 |
2019年 | 84篇 |
2018年 | 85篇 |
2017年 | 96篇 |
2016年 | 87篇 |
2015年 | 77篇 |
2014年 | 79篇 |
2013年 | 231篇 |
2012年 | 55篇 |
2011年 | 66篇 |
2010年 | 48篇 |
2009年 | 79篇 |
2008年 | 81篇 |
2007年 | 79篇 |
2006年 | 96篇 |
2005年 | 89篇 |
2004年 | 66篇 |
2003年 | 59篇 |
2002年 | 55篇 |
2001年 | 45篇 |
2000年 | 39篇 |
1999年 | 49篇 |
1998年 | 51篇 |
1997年 | 36篇 |
1996年 | 31篇 |
1995年 | 31篇 |
1994年 | 44篇 |
1993年 | 24篇 |
1992年 | 28篇 |
1991年 | 16篇 |
1990年 | 9篇 |
1989年 | 18篇 |
1988年 | 16篇 |
1987年 | 15篇 |
1986年 | 28篇 |
1985年 | 25篇 |
1984年 | 19篇 |
1983年 | 20篇 |
1982年 | 13篇 |
1981年 | 21篇 |
1980年 | 20篇 |
1979年 | 20篇 |
1978年 | 19篇 |
1977年 | 30篇 |
1976年 | 20篇 |
1975年 | 9篇 |
1974年 | 4篇 |
排序方式: 共有2416条查询结果,搜索用时 15 毫秒
1.
Nine men participated in two experiments to determine the effects of increased response requirement and alcohol administration on free-operant aggressive responding. Two response buttons (A and B) were available. Pressing Button A was maintained by a fixed-ratio 100 schedule of point presentation. Subjects were instructed that completion of each fixed-ratio 10 on Button B resulted in the subtraction of a point from a fictitious second subject. Button B presses were defined as aggressive because they ostensibly resulted in the presentation of an aversive stimulus to another person. Aggressive responses were engendered by a random-time schedule of point loss and were maintained by initiation of intervals free of point loss. Instructions attributed these point losses to Button B presses of the fictitious other subject. In Experiment 1, increasing the ratio requirement on Button B decreased the number of ratios completed in 4 of 5 subjects. In Experiment 2, the effects of placebo and three alcohol doses (0.125, 0.25, and 0.375 g/kg) were determined when Button B presses were maintained at ratio values of 20, 40 and 80. Three subjects who reduced aggressive responding with increasing fixed-ratio values reduced aggressive responding further at higher alcohol doses. One subject who did not reduce aggressive responding with increasing fixed-ratio values increased aggressive responding at the highest alcohol dose. The results of this study support suggestions that alcohol alters aggressive behavior by reducing the control of competing contingencies. 相似文献
2.
The multiple and long-term effects of functional communication training relative to a common reductive procedure (time-out from positive reinforcement) were evaluated. Twelve children participated in a functional analysis of their challenging behaviors (Study 1), which implicated adult attention as a maintaining variable. The children were then matched for chronological age, mental age, and language age and assigned to two groups. One group received functional communication training as an intervention for their challenging behavior, and the second group received time-out as a contrast. Both interventions were initially successful (Study 2), but durable results were achieved only with the group that received functional communication training across different stimulus conditions (Study 3). Students whose challenging behaviors were previously reduced with time-out resumed these behaviors in the presence of naive teachers unaware of the children's intervention history. The value of teaching communicative responses to promote maintenance is discussed as it relates to the concept of functional equivalence. 相似文献
3.
Binary programming models are presented to generate parallel tests from an itembank. The parallel tests are created to match item for item an existing seed test and match user supplied taxonomic specifications. The taxonomic specifications may be either obtained from the seed test or from some other user requirement. An algorithm is presented along with computational results to indicate the overall efficiency of the process. Empirical findings based on an itembank for the Arithmetic Reasoning section of the Armed Services Vocational Aptitude Battery are given.The Office of Naval Research, Program in Cognitive Science, N00014-87-C-0696 partially supported the work of Douglas H. Jones. The Rutgers Research Resource Committee of the Graduate School of Management partially supported the work of Douglas H. Jones and Ing-Long Wu. A Thomas and Betts research fellowship partially supported the work of Ing-Long Wu. The Human Resources Laboratory, United States Air Force, partially supported the work of Ronald Armstrong. The authors benefited from conversations with Dr. Wayne Shore, Operational Technologies, San Antonio, Texas. The order of authors' names is alphabetical and denotes equal authorship. 相似文献
4.
James B. Freeman 《Argumentation》1992,6(2):219-275
5.
Sociobiological theory suggests that aggression coupled with altruism is highly adaptive for males in all social systems, including the family, whereas sex-role convergence theory indicates that lower levels of aggression are most adaptive for men, particularly at mid-life. The purpose of this study was to determine the role that testosterone, as a proxy for aggression, plays as an adaptive mechanism in the lives of middle-aged males. The sample used in this study consisted of 37 middle-aged (39–50 years of age) males employed in professional occupations in a midwestern metropolitan area. Testosterone levels were regressed on factors typically found to be related to male satisfaction with family life at mid-life: marital satisfaction, parent-adolescent communication, amount of emotional expressiveness, and androgynous characteristics; recent positive and negative stressors and trait anxiety were statistically controlled. Results of step-wise multiple regression analysis indicated that low levels of testosterone were significantly (R = .34, P < .01) related to enhanced marital and parental relationships and androgynous behaviors; however, emotional expressiveness was significantly related to high levels of testosterone. 相似文献
6.
William Stout 《Psychometrika》1987,52(4):589-617
Assuming a nonparametric family of item response theory models, a theory-based procedure for testing the hypothesis of unidimensionality of the latent space is proposed. The asymptotic distribution of the test statistic is derived assuming unidimensionality, thereby establishing an asymptotically valid statistical test of the unidimensionality of the latent trait. Based upon a new notion of dimensionality, the test is shown to have asymptotic power 1. A 6300 trial Monte Carlo study using published item parameter estimates of widely used standardized tests indicates conservative adherence to the nominal level of significance and statistical power averaging 81 out of 100 rejections for examinee sample sizes and psychological test lengths often incurred in practice.The referees' comments were remarkably detailed and greatly enhanced the writeup and sensitized the author to certain pertinent issues. Discussions with Fritz Drasgow, Lloyd Humphreys, Dennis Jennings, Brian Junker, Robert Linn, Ratna Nandakumar, and Robin Shealy were also very useful.This research was supported by the Office of Naval Research under grant N00014-84-K-0186; NR 150-533, and by the National Science Foundation under grant DMS 85-03321. 相似文献
7.
A number of models for categorical item response data have been proposed in recent years. The models appear to be quite different.
However, they may usefully be organized as members of only three distinct classes, within which the models are distinguished
only by assumptions and constraints on their parameters. “Difference models” are appropriate for ordered responses, “divide-by-total”
models may be used for either ordered or nominal responses, and “left-side added” models are used for multiple-choice responses
with guessing. The details of the taxonomy and the models are described in this paper.
The present study was supported in part by two postdoctoral fellowships awarded to Lynne Steinberg: an Educational Testing
Service Postdoctoral Fellowship at ETS, Princeton, NJ and an NIMH Individual National Research Service Award at Stanford University,
Stanford, CA. Helpful comments by the editor and three anonymous reviewers are gratefully acknowledged. 相似文献
8.
9.
ObjectivesThe aim of this study was to compare three different modes of an acute bout of exercise – endurance, strength, and coordination – in their effects on adolescents' attention.DesignThis was a preregistered, prospective, randomized intervention study with four groups and two distinct measurement occasions.MethodEighty adolescent students aged 15–18 years were randomized to one of three exercise intervention groups (endurance, strength, coordination) or to a non-exercise, control group. The exercise interventions lasted for 25 min. The random assignment to the study groups was stratified according to participants' age and gender. Before and after the exercise intervention, all participants completed the revised d2-test of attention. A 4 × 2 repeated measures ANOVA with contrast-coded test was used as the main analysis method.ResultsAttentional test performance increased from before to after the exercise intervention for all exercise groups, as compared with the control group. The three exercise groups improved equally and did not differ in their attentional scores after the intervention.ConclusionsAn acute bout of exercise was in general beneficial for adolescent students' attention, while the mode of the provided exercise training was not decisive. School directors and teachers are encouraged to incorporate exercise-related breaks into their school plan. 相似文献
10.