全文获取类型
收费全文 | 22849篇 |
免费 | 1703篇 |
国内免费 | 48篇 |
出版年
2020年 | 234篇 |
2019年 | 246篇 |
2018年 | 469篇 |
2017年 | 453篇 |
2016年 | 536篇 |
2015年 | 380篇 |
2014年 | 340篇 |
2013年 | 1476篇 |
2012年 | 818篇 |
2011年 | 916篇 |
2010年 | 476篇 |
2009年 | 530篇 |
2008年 | 569篇 |
2007年 | 552篇 |
2006年 | 475篇 |
2005年 | 1661篇 |
2004年 | 1058篇 |
2003年 | 812篇 |
2002年 | 497篇 |
2001年 | 832篇 |
2000年 | 747篇 |
1999年 | 556篇 |
1998年 | 252篇 |
1997年 | 220篇 |
1996年 | 223篇 |
1995年 | 196篇 |
1994年 | 195篇 |
1993年 | 194篇 |
1992年 | 451篇 |
1991年 | 434篇 |
1990年 | 453篇 |
1989年 | 430篇 |
1988年 | 392篇 |
1987年 | 359篇 |
1986年 | 376篇 |
1985年 | 349篇 |
1984年 | 284篇 |
1983年 | 224篇 |
1979年 | 235篇 |
1978年 | 175篇 |
1975年 | 216篇 |
1974年 | 284篇 |
1973年 | 248篇 |
1972年 | 262篇 |
1971年 | 221篇 |
1970年 | 186篇 |
1969年 | 239篇 |
1968年 | 269篇 |
1967年 | 211篇 |
1966年 | 240篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
111.
112.
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
113.
Choice with delayed and probabilistic reinforcers: effects of variability, time between trials, and conditioned reinforcers.
下载免费PDF全文
![点击此处可从《Journal of the experimental analysis of behavior》网站下载免费的PDF全文](/ch/ext_images/free.gif)
In a discrete-trials procedure with pigeons, a response on a green key led to a 4-s delay (during which green houselights were lit) and then a reinforcer might or might not be delivered. A response on a red key led to a delay of adjustable duration (during which red houselights were lit) and then a certain reinforcer. The delay was adjusted so as to estimate an indifference point--a duration for which the two alternatives were equally preferred. Once the green key was chosen, a subject had to continue to respond on the green key until a reinforcer was delivered. Each response on the green key, plus the 4-s delay that followed every response, was called one "link" of the green-key schedule. Subjects showed much greater preference for the green key when the number of links before reinforcement was variable (averaging four) than when it was fixed (always exactly four). These findings are consistent with the view that probabilistic reinforcers are analogous to reinforcers delivered after variable delays. When successive links were separated by 4-s or 8-s "interlink intervals" with white houselights, preference for the probabilistic alternative decreased somewhat for 2 subjects but was unaffected for the other 2 subjects. When the interlink intervals had the same green houselights that were present during the 4-s delays, preference for the green key decreased substantially for all subjects. These results provided mixed support for the view that preference for a probabilistic reinforcer is inversely related to the duration of conditioned reinforcers that precede the delivery of food. 相似文献
114.
In two experiments, key pecking of pigeons was maintained by a variable-interval 180-s schedule of food presentation. Conjointly, a second schedule delivered response-dependent electric shock. In the first experiment, shocks were presented according to either a variable-interval or a nondifferential interval-percentile schedule. The variable-interval shock schedule differentially delivered shocks following long interresponse times. Although the nondifferential shock schedules delivered shocks less differentially with respect to interresponse times, the two shock schedules equally reduced the relative frequency of long interresponse times. The second experiment differentially shocked long or short interresponse times in different conditions, with resulting decreases in the relative frequency of the targeted interresponse times. These experiments highlight the importance of selecting the appropriate level of analysis for the interaction of behavior and environment. Orderly relations present at one level of analysis (e.g., interresponse times) may not be revealed at other levels of analysis (e.g., overall response rate). 相似文献
115.
ALCOVE: an exemplar-based connectionist model of category learning. 总被引:16,自引:0,他引:16
J K Kruschke 《Psychological review》1992,99(1):22-44
ALCOVE (attention learning covering map) is a connectionist model of category learning that incorporates an exemplar-based representation (Medin & Schaffer, 1978; Nosofsky, 1986) with error-driven learning (Gluck & Bower, 1988; Rumelhart, Hinton, & Williams, 1986). Alcove selectively attends to relevant stimulus dimensions, is sensitive to correlated dimensions, can account for a form of base-rate neglect, does not suffer catastrophic forgetting, and can exhibit 3-stage (U-shaped) learning of high-frequency exceptions to rules, whereas such effects are not easily accounted for by models using other combinations of representation and learning method. 相似文献
116.
K O'Brien 《Psychological reports》1992,71(1):147-153
Less is known about the effects of primary relationships on psychological health for homosexual men and women than for heterosexual men and women. Given the HIV/AIDS epidemic, the primary relationships of homosexual men are especially important to examine at the present time. Using questionnaire data collected from 259 homosexual men, this study examined the effects of status and quality of relationship on psychological health. Analysis indicated that homosexual men who are in primary relationships experience fewer depressive symptoms and greater well-being than other homosexual men but that being in a relationship does not predict changes in these outcomes over time. Men who report high quality of relationship show improvements over time in psychological health. These findings are discussed in light of the HIV/AIDS epidemic. 相似文献
117.
This article examined the relationship between impulsiveness and attitudes toward institutional authority among Australian secondary school students. Reliable questionnaire measures of these constructs were completed by 48 boys and 57 girls, about 14 years of age. Correlations between impulsiveness and attitude to authority differed between the sexes, with a significant negative correlation of -.43 being obtained for boys only. 相似文献
118.
Analyses of responses from a clinical sample of 120 patients (primarily schizophrenics) and from 158 college students to the Cognitive Slippage Scale, a scale designed by Miers and Raulin to identify speech deficits and confused thinking in schizophrenic and schizotypal personality disorders showed high internal reliability; Cronbach's coefficients alpha were .89 and .86 in the clinical and college student samples, respectively. The mean scale scores significantly differentiated the two samples. Also, change scores over 4 wk. showed adequate stability for both samples. Item analysis indicated Items 11, 20, 21, and 28 may not reliably discriminate between schizophrenic and college student samples. Over-all, these preliminary results are consistent with the reliability and validity of the scale. 相似文献
119.
Sex differences in self-disclosure: a meta-analysis. 总被引:14,自引:0,他引:14
A meta-analysis of 205 studies involving 23,702 Ss was conducted to determine whether there are sex differences in self-disclosure. Across these studies, women disclosed slightly more than men (d = .18). This effect size was not homogeneous across studies. Several moderator variables were found. Sex of target and the interaction effect of relationship to target and measure of self-disclosure moderated the effect of sex on self-disclosure. Sex differences in self-disclosure were significantly greater to female and same-sex partners than to opposite-sex or male partners. When the target had a relationship with the discloser (i.e., friend, parent, or spouse), women disclosed more than men regardless of whether self-disclosure was measured by self-report or observation. When the target was a stranger, men reported that they disclosed similarly to women; however, studies using observational measures of self-disclosure found that women disclosed more than men. 相似文献
120.
Psychological compensation: a theoretical framework. 总被引:1,自引:0,他引:1
The 2 main objectives of this article are to review a variety of literatures in which the concept of compensation is used and to integrate the results of this review into a general framework of compensation. The review focuses on 4 domains of psychological inquiry: compensation for sensory handicaps, cognitive deficits, interpersonal losses, and brain injury. In the proposed framework, underlying dimensions and 4 basic steps in the progression of compensatory behavior are distinguished. The latter include origins, mechanisms, forms, and consequences. Finally, we describe ways in which researchers in particular domains can benefit from the global, process-oriented framework we propose. For most of the areas of compensation research reviewed, investigators can profit from a consideration of a broader selection of dimensions, additional steps in the process, alternative outcomes, and both objective and subjective assessment procedures. 相似文献