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   159篇
  免费   47篇
  国内免费   14篇
  2023年   4篇
  2022年   2篇
  2021年   6篇
  2020年   6篇
  2019年   6篇
  2018年   7篇
  2017年   8篇
  2016年   12篇
  2015年   6篇
  2014年   4篇
  2013年   16篇
  2012年   9篇
  2011年   6篇
  2010年   5篇
  2009年   6篇
  2008年   5篇
  2007年   13篇
  2006年   5篇
  2005年   4篇
  2004年   13篇
  2003年   2篇
  2002年   2篇
  2001年   6篇
  2000年   6篇
  1999年   5篇
  1998年   10篇
  1997年   5篇
  1996年   1篇
  1995年   4篇
  1994年   2篇
  1993年   4篇
  1992年   1篇
  1991年   1篇
  1989年   1篇
  1988年   2篇
  1987年   2篇
  1986年   4篇
  1985年   2篇
  1984年   2篇
  1983年   1篇
  1982年   2篇
  1981年   1篇
  1980年   1篇
  1979年   3篇
  1978年   1篇
  1977年   1篇
  1976年   3篇
  1975年   2篇
排序方式: 共有220条查询结果,搜索用时 31 毫秒
1.
Millsap and Meredith (1988) have developed a generalization of principal components analysis for the simultaneous analysis of a number of variables observed in several populations or on several occasions. The algorithm they provide has some disadvantages. The present paper offers two alternating least squares algorithms for their method, suitable for small and large data sets, respectively. Lower and upper bounds are given for the loss function to be minimized in the Millsap and Meredith method. These can serve to indicate whether or not a global optimum for the simultaneous components analysis problem has been attained.Financial support by the Netherlands organization for scientific research (NWO) is gratefully acknowledged.  相似文献   
2.
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   
3.
It is suggested that molar streams of behavior are constructed of various arrangements of three elementary constituents (elicited, evoked, and emitted response classes). An eight-cell taxonomy is elaborated as a framework for analyzing and synthesizing complex behavioral repertoires based on these functional units. It is proposed that the local force binding functional units into a smoothly articulated kinetic sequence arises from temporally arranged relative response probability relationships. Behavioral integration is thought to reflect the joint influence of the organism's hierarchy of relative response probabilities, fluctuating biological states, and the arrangement of environmental and behavioral events in time.  相似文献   
4.
In a discrete-trial conditional discrimination procedure, 4 pigeons obtained food reinforcers by pecking a key with a short latency on trials signaled by one stimulus and by pecking the same key with a long latency on trials signaled by a second stimulus. The physical difference between the two stimuli and the temporal separation between the latency values required for reinforcement were varied factorially over four sets of conditions, and the ratio of reinforcer rates for short and long latencies was varied within each set of conditions. Stimulus discrimination varied directly with both stimulus and response differences and was unaffected by the reinforcer ratio. Sensitivity to reinforcement, estimated by generalized-matching-law fits to the data within each set of conditions, varied directly with the response difference but inversely with the stimulus difference arranged between sets of conditions. Because variations in stimulus differences, response differences, and reinforcer differences did not have equivalent effects, these findings question the functional equivalence of the three terms of the discriminated operant: antecedent stimuli, behavior, and consequences.  相似文献   
5.
Key pecking of four birds was reinforced with food according to a two-component multiple variable-interval 1-minute variable-interval 4-minute schedule. In addition, key pecking was punished by a brief shock according to a variable-interval 30-second schedule during both components of the multiple schedule. The intensity of the shock was varied. For all birds, punishment had a stronger suppressive effect on the responding maintained by the leaner food schedule, and the ratio of responding during the two components of the multiple schedule became closer to the ratio of reinforcement as shock intensity was increased, as the relative law of effect predicts. At the higher shock intensity, there was some evidence that the ratio of responses overmatched the ratio of reinforcements.  相似文献   
6.
When measuring the same variables on different occasions, two procedures for canonical analysis with stationary compositing weights are developed. The first, SUMCOV, maximizes the sum of the covariances of the canonical variates subject to norming constraints. The second, COLLIN, maximizes the largest root of the covariances of the canonical variates subject to norming constraints. A characterization theorem establishes a model building approach. Both methods are extended to allow for Cohort Sequential Designs. Finally a numerical illustration utilizing Nesselroade and Baltes data is presented.The authors wish to thank John Nesselroade for permitting us to use the data whose analysis we present.  相似文献   
7.
Many authors have demonstrated for idealized item configurations that equal item weights are often virtually as good for a particular predictive purpose as the item weights that are theoretically optimal. What has not been heretofore clear, however, is what happens to the similarity between weighted and unweighted composites of the same items when the item configuration's variance structure is complex.  相似文献   
8.
Pigeons were trained on a multiple variable-interval variable-interval schedule of reinforcement. One component was then changed to a variation of a fixed-interval schedule in which the same rate of reinforcement was obtained as previously but the location of the reinforcer was fixed within the component. The effects of different temporal locations were compared. An increase in response rate for the unchanged variable-interval component (behavioral contrast) occurred when the reinforcer was located in the middle or at the end of the FI component, but response suppression occurred when it was located at the beginning of the component. The pattern of results cannot be explained by any previous theories of contrast. The overall response rates, and the pattern of local rates within the components, were consistent with the hypothesis that the major determinant of the contrast effect was the transition to a lower reinforcement rate following the unchanged component.  相似文献   
9.
对1353名高中生进行问卷调查,探究亲子间科技干扰与青少年网络人际关系成瘾之间的关系,相对剥夺感的中介作用及内在觉知的调节作用,结果表明:(1)亲子间科技干扰正向预测青少年网络人际关系成瘾;(2)相对剥夺感是亲子间科技干扰与网络人际关系成瘾之间的中介变量;(3)亲子间科技干扰与网络人际关系成瘾的间接效应前半段受到内在觉知的调节。因此,亲子间科技干扰和网络人际关系成瘾之间存在有调节的中介效应。  相似文献   
10.
关系从句是人类语言领域句法结构较为复杂的句式,汉语3~5岁儿童是否具有加工关系从句的认知能力,以及该能力是否受句法结构和语义因素的影响,成为该领域当前研究的热点。本研究选取120名3~6岁学龄前儿童,以汉语主、宾关系从句为研究材料,通过操纵从句中核心名词的生命性格局对上述问题进行了考察。结果显示:(1)汉语领域内,3~4岁儿童基本上具备了理解句式较为简单的关系从句的能力;(2)5~6岁左右的儿童基本上具备了利用语义因素辅助关系从句加工的能力。总之,汉语学龄前儿童具备了加工关系从句的认知能力,且高年级儿童可以利用语义因素辅助从句加工。  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