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   54968篇
  免费   2157篇
  国内免费   34篇
  2020年   588篇
  2019年   666篇
  2018年   904篇
  2017年   916篇
  2016年   1041篇
  2015年   740篇
  2014年   855篇
  2013年   4258篇
  2012年   1606篇
  2011年   1648篇
  2010年   998篇
  2009年   1067篇
  2008年   1462篇
  2007年   1387篇
  2006年   1237篇
  2005年   1111篇
  2004年   1058篇
  2003年   1019篇
  2002年   1061篇
  2001年   1640篇
  2000年   1615篇
  1999年   1178篇
  1998年   553篇
  1997年   519篇
  1992年   1027篇
  1991年   984篇
  1990年   956篇
  1989年   937篇
  1988年   892篇
  1987年   847篇
  1986年   882篇
  1985年   961篇
  1984年   794篇
  1983年   734篇
  1982年   551篇
  1981年   550篇
  1979年   855篇
  1978年   622篇
  1977年   561篇
  1976年   566篇
  1975年   735篇
  1974年   850篇
  1973年   899篇
  1972年   761篇
  1971年   716篇
  1970年   650篇
  1969年   694篇
  1968年   849篇
  1967年   782篇
  1966年   746篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
831.
832.
Recipient's mood, relationship type, and helping   总被引:6,自引:0,他引:6  
We conducted two studies to examine how a potential helper is affected by having a communal orientation toward a relationship with a potential recipient and by the potential recipient's sadness. We hypothesized that (a) having a communal orientation would increase helping and that (b) people high in communal orientation, but not others, would respond to a potential recipient's sadness by increasing helping. These hypotheses were tested in two studies. In Study 1, individual differences in communal orientation toward relationships were measured by using a new communal orientation scale reported for the first time in this article. In Study 2, manipulations were used to lead subjects to desire either a communal or an exchange relationship with another person. In both studies, subjects were exposed to a sad person or to a person in a neutral mood whom they were given a chance to help. As hypothesized, in both studies communally oriented subjects helped the other significantly more than did others. Also as hypothesized, in both studies communally oriented subjects but not others, increased helping in response to the other person's sadness although this effect reached statistical significance only in the second study.  相似文献   
833.
Stimulus class membership established via stimulus-reinforcer relations   总被引:4,自引:4,他引:0  
In an arbitrary matching-to-sample procedure, two mentally retarded subjects learned conditional discriminations with two sets of stimuli. Each set included a spoken name (N1 or N2), an object (O1 or O2), and a printed symbol (S1 or S2). One subject selected conditionally (a) O1 upon N1, and O2 upon N2, and (b) S1 upon O1, and S2 upon O2. The other subject selected conditionally (a) S1 upon N1, and S2 upon N2, and (b) O1 upon S1, and O2 upon S2. For both subjects, selections of O1 and S1 produced one type of food, F1; selections of O2 and S2 produced a different type of food, F2. Both subjects also learned identity-matching performances, selecting O1, O2, S1, S2, F1, and F2 conditionally upon those stimuli as samples; F1 followed selections of O1, S1, and F1; F2 followed selections of O2, S2, and F2. Matching performances consistent with stimulus class formation involving the names, objects, symbols, and foods were demonstrated on probe trials, even though these performances had not been taught explicitly. Next, new objects, X1 and X2, were presented on identity-matching trials, producing F1 and F2, respectively. Without further training, X1 was selected conditionally upon N1, S1, and O1, and X2 was selected upon N2, S2, and O2. When the contingencies were changed so that selections of X1 and X2 were now followed by F2 and F1, respectively, X2 was selected conditionally upon N1, S1, and O1, and X1 was selected upon N2, S2, and O2. Class membership of X1 and X2 had apparently changed. This study provides evidence that reinforcers may become members of stimulus classes, and that new stimuli may become class members through relations with reinforcers.  相似文献   
834.
Adherents to the traditional model of alcoholism explain alcoholic behavior as a consequence of alcoholism. Alcoholism is identified as an unseen, unmeasured entity inherent in alcoholics. This concept parallels the thinking of Copernicus, Kepler, Galileo, and Newton, who believed in an unseen, unmeasurable creator behind the physical world. These traditional approaches contrast with the emergent model of alcoholism and twentieth-century scientific thought. Emergent scientific model adherents explain alcoholic behavior without resort to unseen factors. Since the traditional and emergent scientific models begin with different assumptions, model adherents experience communication difficulties. Future developments with determine which model will dominate the field of alcohol studies and treatment.  相似文献   
835.
Invariance in the MMPI's component structure   总被引:1,自引:0,他引:1  
Bernstein and Garbin (1985b) suggested that the Minnesota Multiphasic Personality Inventory's major clinical scales (excluding Scales ? and 5) can be approximated by an oblique three-component structure: (a) Profile Elevation, (b) Test-taking Attitudes, and (c) Optimism-Pessimism, collectively termed the salient weight model. In this study, we found that both this model and the MMPI's principal component structure remain invariant across race, sex, and, as previously noted, context of testing (job applicants vs. inmates in correctional institutions). We further noted that several alternative definitions of Profile Elevation provide equally satisfactory representation of the relations among the scales. This factor invariance is necessary, but not sufficient, for the MMPI to be viewed as unbiased.  相似文献   
836.
We develop a simple model of switching between the initial links of a concurrent-chain procedure. Behavior is determined by four parameters μ1, μ2, q1, and q2. The first two are the basic rates of switching from Schedule 1 and Schedule 2, respectively. The second two are the probabilities of leaving Schedule 1 and Schedule 2 after the corresponding terminal link has been completed. We show that for fixed values of these four parameters, the relative allocation on the initial links may change as a result of changes in initial-link schedules. The effect can be quite large if the switching rates are low. An implication is that relative allocation is not necessarily a good measure of behavior.  相似文献   
837.
The operant conditioning of response variability under free-operant and discrete-response procedures was investigated. Two pigeons received food only if their pattern of four pecks on two response keys differed from the patterns emitted on the two immediately preceding trials. Under the free-operant procedure, the keys remained illuminated and operative throughout each trial. There was little variability in the response patterns that resulted, and the pigeons received fewer than one third of the available reinforcers. Under the discrete-response procedure, a brief timeout period followed each response. Variability increased under this procedure, and the pigeons obtained three fourths of the available reinforcers. Previous successes and failures to produce response variability may have been due to the use or failure to use, respectively, a discrete-response procedure. Respondent effects inherent in the free-operant procedure may encourage the development of response stereotypy and, in turn, prevent the development of response variability.  相似文献   
838.
The psychology of self-esteem bypasses consequential issues of everyday behavior and moral responsibility in favor of pursuing a global goal of enhanced self-esteem on the assumption that happiness, success, and responsible behavior will automatically follow. The goal is vague and ways of achieving it are confused and conflicting. Greater attention to concrete tasks and challenges and sensitivity to moral issues could help make therapy more clear, effective, and socially useful.  相似文献   
839.
Pigeons' responses were reinforced on a variant of a mixed variable-interval extinction schedule of reinforcement in which the transition to the higher reinforcement rate was signaled by a trace stimulus projected on the response key prior to the onset of the component correlated with food delivery. In the first of two experiments, the duration of the trace stimulus preceding the component correlated with food delivery was varied from 1.5 to 50.0 s and in the second experiment, the reinforcement frequency in the same component was varied from 10 to 60 reinforcers per hour. Pigeons pecked at the trace stimulus preceding the onset of the component correlated with food delivery even though responding was not reinforced in its presence and only one of the changes in reinforcement rate (i.e., from extinction to reinforcement) was signaled. The rate of pecking during the trace stimulus was a function of its duration but not of the reinforcement frequency in the following component. Higher rates generally occurred at the shorter trace-stimulus durations. Component responding following the offset of the trace stimulus was under discriminative control of the trace stimulus whether or not responding occurred in the presence of the trace stimulus.  相似文献   
840.
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