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   65945篇
  免费   3305篇
  国内免费   67篇
  2020年   711篇
  2019年   879篇
  2018年   1269篇
  2017年   1245篇
  2016年   1329篇
  2015年   915篇
  2014年   1127篇
  2013年   5481篇
  2012年   2047篇
  2011年   2157篇
  2010年   1373篇
  2009年   1440篇
  2008年   1995篇
  2007年   1997篇
  2006年   1741篇
  2005年   1626篇
  2004年   1577篇
  2003年   1422篇
  2002年   1468篇
  2001年   2311篇
  2000年   2156篇
  1999年   1642篇
  1998年   857篇
  1997年   736篇
  1996年   718篇
  1995年   666篇
  1994年   644篇
  1993年   665篇
  1992年   1349篇
  1991年   1276篇
  1990年   1258篇
  1989年   1134篇
  1988年   1068篇
  1987年   1045篇
  1986年   1027篇
  1985年   1081篇
  1984年   884篇
  1983年   752篇
  1982年   631篇
  1979年   854篇
  1978年   640篇
  1975年   756篇
  1974年   836篇
  1973年   825篇
  1972年   734篇
  1971年   664篇
  1969年   610篇
  1968年   771篇
  1967年   732篇
  1966年   657篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Two studies are reported on a new Anger Control Inventory based on a cognitive-behavioral person-situation interaction model. In Study 1, the inventory responses of 118 clinical subjects and 190 normal subjects were correlated with an anger problem criterion based on observable signs. Factor analyses were conducted to clarify the construct base of the inventory. In Study 2, comparisons were made between the inventory responses of 100 spouse batterers and 96 normal subjects. Significant differences between the pretreatment and posttreatment scores of 65 batterers given treatment in anger control were obtained on the inventory scales, which were found to be correlated with the problem criterion and discriminating between the clinical and normal groups. The construct validity and clinical utility of the Anger Control Inventory are discussed.  相似文献   
993.
This study explored the relationship among love deprivation, Performance greater than Verbal discrepancy, and violent crime in a sample of juvenile probationers. Love deprivation and P greater than V discrepancy was significantly related to violent delinquency after adjusting for the effects of both race and social class, two variables often closely associated with violent delinquency. Also, love deprivation was strongly related to P greater than V discrepancy. We speculated that high performance IQ scores relative to verbal scores are a function of a lack of disruption in the short-term memory mechanisms of high P greater than V subjects, that this nondisruption is a function of hyporeactive autonomic nervous systems, and that this hyporeactivity could itself be a function of early love deprivation.  相似文献   
994.
The purpose of this study was to explore differences in body satisfaction among female adolescents 14 to 18 years of age. Principal components analysis of a body cathexis measure completed by 751 high school cheerleaders indicated that six factors defined the adolescents' attitudes toward their bodies: satisfaction with the midsection and overall appearance, peripheral body parts, hair and face, mouth, hands, and height. An Age X Body Satisfaction multivariate analysis of variance (MANOVA) was conducted; a Bonferroni adjusted alpha of .007 was established for subsequent ANOVAs. Satisfaction with the mouth increased significantly as age increased, and a similar but nonsignificant trend was found for peripheral body parts. The findings contradict previous research reporting no age differences in the body satisfaction of adolescents. Role demands and physical maturation of the cheerleaders may explain differences based on age.  相似文献   
995.
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   
996.
This article deals with appropriate communication and interpersonal skills that nurses may use in order to support patients who are experiencing self-concept changes related to their health problems. Three areas of patient need related to self-concept are explored. The stages of adaptation to loss and the crucial task of grief work are reviewed, and nursing interventions designed to strengthen the self-concept and support patients as they adapt to loss are suggested. Sensitive communication, although a low-visibility nursing skill, is cited as critical in assisting the patient to achieve an optimum level of wellness.  相似文献   
997.
Six pigeons were trained in a discrete-trials signal-detection procedure to discriminate between a fixed-duration stimulus (5 s or 20 s) and a set of variable durations ranging from 2.5 s to 57.5 s in steps of 5 s. For each fixed-duration stimulus, the ratio of reinforcer frequencies contingent upon reporting the fixed versus the variable stimulus was systematically manipulated. Detection performance was well controlled by both the stimulus value and the reinforcer ratio. Both the discriminability between the fixed duration and the set of variable durations, and the discriminability between the fixed duration and each of the variable durations, were independent of the reinforcer-frequency ratio when discriminability was measured as log d. The sensitivity of response bias to reinforcement-ratio changes was independent of the value of the fixed duration, but was not independent of the discriminability of the variable durations from the fixed durations. Under current models, discriminability measures in complex temporal discrimination may be independent of biasing manipulations, but bias measures are not independent of stimulus values.  相似文献   
998.
Pigeons' choices between alternatives that provided different percentages of reinforcement in mixed schedules were studied using the concurrent-chains procedure. In Experiment 1, the alternatives were terminal-link schedules that were equal in delay and magnitude of reinforcement, but that provided different percentages of reinforcement, with one schedule providing, reinforcement twice as reliably as the other. All pigeons preferred the more reliable schedule, and their level of preference was not systematically affected by variation in the absolute percentage values, or in the magnitude of reinforcement. In Experiment 2, preference for a schedule providing 100% reinforcement over one providing 33% reinforcement increased systematically with increases in the duration of the terminal links. In contrast, preference decreased systematically with increases in the duration of the initial links. Experiment 3 examined choice with equal percentages of reinforcement but unequal delays to reinforcement. Preference for the shorter delay to reinforcement was not systematically affected by variation in the absolute percentage of reinforcement. The overall pattern of results supported predictions based on an extension of the delay-reduction hypothesis to choice procedures involving mixed schedules of percentage reinforcement.  相似文献   
999.
Effects of delayed conditioned reinforcement in chain schedules.   总被引:3,自引:3,他引:0  
The contingency between responding and stimulus change on a chain variable-interval 33-s, variable-interval 33-s, variable-interval 33-s schedule was weakened by interposing 3-s delays between either the first and second or the second and third links. No stimulus change signaled the delay interval and responses could occur during it, so the obtained delays were often shorter than the scheduled delay. When the delay occurred after the initial link, initial-link response rates decreased by an average of 77% with no systematic change in response rates in the second or third links. Response rates in the second link decreased an average of 59% when the delay followed that link, again with little effect on response rates in the first or third links. Because the effect of delaying stimulus change was comparable to the effect of delaying primary reinforcement in a simple variable-interval schedule, and the effect of the unsignaled delay was specific to the link in which the delay occurred, the results provide strong evidence for the concept of conditioned reinforcement.  相似文献   
1000.
In a conditional discrimination procedure, pigeons' observing responses were analyzed to examine whether two color stimuli (blue or red), conditionally related to whether each of two line stimuli (vertical or horizontal) accompanied reinforcement or nonreinforcement, functioned as conditioned reinforcers. If a variable-interval (VI) 10-s requirement was fulfilled, an observing response produced onset of a color stimulus. A little later, a line stimulus was presented independently of responding, added to the color stimulus to form a compound stimulus. If 55 s elapsed with a response not having occurred either through 55 s or after the variable-interval 10-s had timed out, one of the color-line compound stimuli was presented independently of responding. To control for sensory reinforcement effects and for earlier entrance to the later link, a simple discrimination procedure also was conducted in which reinforcement was not correlated with the color stimuli but with the line stimuli only. As in the conditional discrimination, the observing response also could produce earlier presentation of blue or red. The observing response occurred more frequently during the conditional discrimination than during the simple discrimination. The results were related to different theoretical accounts of conditioned reinforcement, particularly the information hypothesis.  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