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   3356篇
  免费   1012篇
  国内免费   34篇
  2019年   38篇
  2014年   42篇
  2013年   267篇
  2012年   70篇
  2011年   95篇
  2010年   142篇
  2009年   200篇
  2008年   112篇
  2007年   131篇
  2006年   87篇
  2005年   103篇
  2004年   122篇
  2003年   113篇
  2002年   94篇
  2001年   143篇
  2000年   70篇
  1999年   102篇
  1998年   86篇
  1997年   67篇
  1996年   104篇
  1995年   91篇
  1994年   84篇
  1993年   85篇
  1992年   101篇
  1991年   100篇
  1990年   89篇
  1989年   90篇
  1988年   77篇
  1987年   64篇
  1986年   51篇
  1985年   55篇
  1984年   52篇
  1982年   50篇
  1981年   37篇
  1980年   39篇
  1979年   43篇
  1976年   39篇
  1974年   36篇
  1973年   46篇
  1972年   52篇
  1971年   56篇
  1970年   41篇
  1968年   67篇
  1967年   54篇
  1966年   59篇
  1965年   43篇
  1964年   85篇
  1963年   76篇
  1962年   49篇
  1961年   40篇
排序方式: 共有4402条查询结果,搜索用时 15 毫秒
11.
Three severely mentally retarded adolescents were studied under discrete-trial procedures in which a choice was arranged between edible reinforcers that differed in magnitude and, in some conditions, delay. In the absence of delays the larger reinforcer was consistently chosen. Under conditions in which the smaller reinforcer was not delayed, increasing the delay to delivery of the larger reinforcer decreased the percentage of trials in which that reinforcer was chosen. All subjects directed the majority of choice responses to the smaller reinforcer when the larger reinforcer was sufficiently delayed, although the value at which this occurred differed across subjects. Under conditions in which the larger reinforcer initially was sufficiently delayed to result in preference for the smaller one, progressively increasing in 5-s increments the delay to both reinforcers increased percentage of trials with the larger reinforcer chosen. At sufficiently long delays, 2 of the subjects consistently chose the larger, but more delayed, reinforcer, and the 3rd subject chose that reinforcer on half of the trials. These results are consistent with the findings of prior studies in which adult humans responded to terminate noise and pigeons responded to produce food.  相似文献   
12.
A cost-benefit analysis of demand for food.   总被引:20,自引:17,他引:3       下载免费PDF全文
Laboratory studies of consumer demand theory require assumptions regarding the definition of price in the absence of a medium of exchange (money). In this study we test the proposition that the fundamental dimension of price is a cost-benefit ratio expressed as the effort expended per unit of food value consumed. Using rats as subjects, we tested the generality of this "unit price" concept by varying four dimensions of price: fixed-ratio schedule, number of food pellets per fixed-ratio completion, probability of reinforcement, and response lever weight or effort. Two levels of the last three factors were combined in a 2 x 2 x 2 design giving eight groups. Each group was studied under a series of six FR schedules. Using the nominal values of all factors to determine unit price, we found that grams of food consumed plotted as a function of unit price followed a single demand curve. Similarly, total work output (responses x effort) conformed to a single function when plotted in terms of unit price. These observations provided a template for interpreting the effects of biological factors, such as brain lesions or drugs, that might alter the cost-benefit ratio.  相似文献   
13.
Aggregate item response analysis   总被引:1,自引:0,他引:1  
A stochastic postulate is given for the multiple-item, successive-intervals scaling of populations. The logistic equivalent of this postulate provides an aggregate item response model in which a unidimensional submodel may be nested. This reduction provides a subtractive conjoint measurement of several items and stimuli on the same latent scale. Generalized-least-squares methods are used to estimate and test the multiple-item model, and its unidimensional reduction, on aggregate survey responses. The entire procedure is illustrated with an analysis of semantic-differential attitude data. This analysis exhibits an item selection procedure that is applicable to various social constructs.The authors dedicate this paper to the memory and contributions of Clyde Coombs.The programming and data analyses for the present paper were carried out by José Ventura of the Department of Industrial and Systems Engineering, and Jerry Meiten of the Department of Statistics, University of Florida.The study was also supported by the College of Business Administration, University of Florida, and the Faculty of Social Sciences, Hebrew University of Jerusalem.  相似文献   
14.
There appears to be a strong relationship between mass media portrayals of violence and real-life violence itself. This article reviews the available literature on the effects of media treatment of sports violence; analyzes the theoretical explanations for this treatment; and makes proposals on how the problems of both sports violence and its media coverage may be remedied, with a particular focus on amateur hockey in Canada.  相似文献   
15.
The belief is widely held that humor is related to recovery from, and perhaps an increased resistance to, coronary and other stress-related diseases. Such generalizations do not typically distinguish between benign and hostile humor. In the present research, the relationship between a measure of proneness to coronary heart disease (CHD) and appreciation of hostile and nonhostile humor is examined. In two studies, one with college students and one with patients suffering from CHD, the relationship between humor preferences and the coronary-prone (Type A) behavior pattern was examined. Each subject was given the Jenkins Activity Survey as a measure of the coronary-prone personality type, and aggressive and nonaggressive jokes to rate for funniness. Hostile humor was preferred to nonhostile humor by all groups, but among those suffering from CHD, those who could be classified as “Type B’s” preferred nonhostile humor. The results indicate that those less prone to CHD appreciate both hostile and nonhostile humor, while Type A’s seem to enjoy hostile humor only.  相似文献   
16.
Males were randomly assigned to view either (1) a film clip featuring hockey fights or (2) a film of nonaggressive hockey action or (3) a no-film control condition after having first been angered or treated politely by an experimental confederate. The dependent variable was represented by a measure of aggressive mood and a behavioral measure of retaliatory aggression. Analyses revealed that both angered and nonangered subjects exhibited an increase in aggressive mood following exposure to the fight film. However, the analysis involving retaliatory aggression against the confederate yielded an anger x film interaction. While angered subjects were more aggressive than nonangered, only angered subjects retaliated against the confederate after viewing the fight film. The results were discussed in terms of Berkowitz’s (1974) aggressive cue theory. A version of this paper was presented at the meeting of the North American Society for the Sociology of Sport, Edmonton, Canada, November 1987.  相似文献   
17.
The concept of developmental amnesia is proposed to describe the impairment of normal memories during a person's school age life. One hundred psychotherapy patients were interviewed and the age of earliest memories ranged from 1–12 years, with a mode of 5 years. Memory was continuous for 53% of patients by 1st grade, while 18% reported life memory was still episodic at age 18 or later. Parental alcohol problems were associated with delay of continuous memories.  相似文献   
18.
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   
19.
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   
20.

The effects of varying decision outcome dispersion on organizational decision making were investigated under individual and group decision making conditions. Thirty-six female and pg]36 male subjects made decisions for organizational decision scenarios in which outcomes affected primarily the decision maker, people other than the decision maker, or a group of which the decision maker was a member. Subjects rated their levels of perceived risk and confidence in their decisions and made decisions within a simulated context of either a small or a large organization. Results indicated that subjects perceived significantly less risk and more confidence in their decisions when outcomes affected primarily themselves rather than others regardless of whether the decisions were made individually or by a group. Males perceived their decisions as significantly more risky than females. Induced organizational size did not significantly influence decision making.

  相似文献   
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