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   1905篇
  免费   135篇
  国内免费   31篇
  2071篇
  2024年   42篇
  2023年   59篇
  2022年   26篇
  2021年   42篇
  2020年   88篇
  2019年   109篇
  2018年   84篇
  2017年   112篇
  2016年   81篇
  2015年   65篇
  2014年   83篇
  2013年   330篇
  2012年   57篇
  2011年   57篇
  2010年   46篇
  2009年   53篇
  2008年   59篇
  2007年   42篇
  2006年   67篇
  2005年   61篇
  2004年   58篇
  2003年   64篇
  2002年   50篇
  2001年   45篇
  2000年   31篇
  1999年   32篇
  1998年   31篇
  1997年   31篇
  1996年   18篇
  1995年   20篇
  1994年   16篇
  1993年   11篇
  1992年   13篇
  1991年   10篇
  1990年   6篇
  1989年   6篇
  1988年   8篇
  1987年   4篇
  1986年   5篇
  1985年   9篇
  1984年   3篇
  1983年   5篇
  1982年   3篇
  1981年   5篇
  1980年   1篇
  1979年   5篇
  1978年   5篇
  1977年   3篇
  1976年   8篇
  1975年   2篇
排序方式: 共有2071条查询结果,搜索用时 0 毫秒
1.
The Colorado Occupant Protection Project (COPP) intervention provided police with brief instruction concerning the importance of citations for drivers' failure to use child safety seats and special coupons to accompany citations. Coupons were exchangeable by drivers for a safety seat and brief training in its use, plus a waiver of the $50 citation fine. Over 4.5 years of archival records were employed, using an ABA design and a comparison community to evaluate the program. Few tickets were issued for nonuse of safety seats during the 3-year baseline in either community. Citations for nonuse of safety seats increased to over 50 per month during the intervention period at the test site, whereas rates remained essentially zero at the comparison site. After the COPP intervention was removed at the intervention site, citation rates for nonuse of safety seats decreased to about 15 per month. Differences between intervention conditions and settings were statistically significant. During the intervention, officers were 44 times more likely to write citations than were controls. Results suggested that a behavioral program can increase police citation writing for child protection purposes.  相似文献   
2.
We examined two systems of assessing family interactions that are in common usage: a home based observation of free parent-child interaction and a clinic based observation of a structured mother-child problem solving discussion. Participants were 18 depressed, 27 conduct disordered and 16 comparison children and their mothers. Results indicated that: 1) these observations may yield very different data about child, and to a lesser extent, parent behavior, 2) parental affect in the clinic was related to their level of aversive behaviour in the home, 3) levels of both aversive and positive behavior for children and their mothers were correlated within each setting, 4) accuracy of diagnostic classifications made on the basis of the observational data were highest for comparison and conduct disordered children, but lowest for depressed children observed in the clinic, and 5) the inclusion of data on mothers' behavior increased classification accuracy for conduct disordered children only.  相似文献   
3.
We evaluated a procedure for identifying potential reinforcers with profoundly retarded individuals. In Experiment 1, six persons were repeatedly exposed to 16 stimuli, and approach behaviors to each stimulus were used to identify preferred and nonpreferred stimuli. In Experiment 2, we examined the reinforcing properties of preferred and nonpreferred stimuli by delivering them contingently on the occurrence of arbitrarily selected responses. Results revealed that the preferred stimulus conditions typically produced higher rates of responding than did either the baseline or the nonpreferred stimulus conditions, suggesting that the procedure can be used to assess reinforcer value for individuals with limited behavioral repertoires.  相似文献   
4.
Three-way metric unfolding via alternating weighted least squares   总被引:6,自引:3,他引:3  
Three-way unfolding was developed by DeSarbo (1978) and reported in DeSarbo and Carroll (1980, 1981) as a new model to accommodate the analysis of two-mode three-way data (e.g., nonsymmetric proximities for stimulus objects collected over time) and three-mode, three-way data (e.g., subjects rendering preference judgments for various stimuli in different usage occasions or situations). This paper presents a revised objective function and new algorithm which attempt to prevent the common type of degenerate solutions encountered in typical unfolding analysis. We begin with an introduction of the problem and a review of three-way unfolding. The three-way unfolding model, weighted objective function, and new algorithm are presented. Monte Carlo work via a fractional factorial experimental design is described investigating the effect of several data and model factors on overall algorithm performance. Finally, three applications of the methodology are reported illustrating the flexibility and robustness of the procedure.We wish to thank the editor and reviewers for their insightful comments.  相似文献   
5.
We present a multiple regression model that explores post-return adjustment of school-age children who experienced abduction by a parent. The model includes: a) child and family characteristics preceding abduction, b) characteristics of the abduction experience, and c) child and family characteristics following return. Overall, the model accounts for 21% of the variance in post-return adjustment of children (p.05). The most salient finding is that post-return adjustment of children was best explained by characteristics of the child and family before the abduction occurred. Domestic violence perpetrated by one or both parents was the most significant factor.  相似文献   
6.
May's model of pairwise preference determination is used to assess the expected likelihood that a subject's pairwise preference comparisons on three alternatives will be transitive. A closed form representation for this expected likelihood is obtained for each situation considered. When the subject is assumed to act precisely according to rankings on attributes with May's model, the computed expected likelihoods the relatively large. When the subject becomes a probabilistic chooser, as defined in a specific manner, expected likelihoods of transitivity decrease significantly from corresponding values with May's model. For a probabilistic Chooser, there is a significant likelihood that the subject might yield transitive pairwise preferences substantially different than the results suggested by May's model.This research was supported by a grant from the General University Research Program and through a fellowship from the Center for Advanced Study, both of the University of Delaware. Very helpful input from John H. Antil, Meryl P. Gardner, and James M. Munch is also acknowledged.  相似文献   
7.
Tustin (1994) recently observed that an individual's preference for one of two concurrently available reinforcers under low schedule requirements (concurrent fixed-ratio [FR] 1) switched to the other reinforcer when the schedule requirements were high (concurrent FR 10). We extended this line of research by examining preference for similar and dissimilar reinforcers (i.e., those affecting the same sensory modality and those affecting different sensory modalities). Two individuals with developmental disabilities were exposed to an arrangement in which pressing two different panels produced two different reinforcers according to progressively increasing, concurrent-ratio schedules. When two dissimilar stimuli were concurrently available (food and a leisure item), no clear preference for one item over the other was observed, regardless of the FR schedules in effect (FR 1, 2, 5, 10, and 20). By contrast, when two similar stimuli were concurrently available (two food items), a clear preference for one item emerged as the schedule requirements were increased from FR 1 to FR 5 or FR 10. These results are discussed in terms of implications for conducting preference assessments and for selecting reinforcers to be used under training conditions in which response requirements are relatively high or effortful.  相似文献   
8.
We evaluated the effects of choice versus the assignment of tasks of varying preferences on the work engagement of adults with severe disabilities. The combined results of two experiments suggest that the relative preference for a task may be an important variable in the effectiveness of choice for some individuals.  相似文献   
9.
Two families, in which the children had been placed in foster care due to abuse and neglect by parents who had disabilities, were studied. In the first case, the mother was instructed in skills that our assessment suggested were important for her child's survival. The mother readily acquired and applied these skills, a fact reflected both in changes in her behavior and in changes in the child's well-being. In the second case, the parent's incremental resumption of child custody was made contingent upon completion of relevant parenting tasks. Initially, improvements in the completion of such tasks were evident, but over time and with the onset of militating factors, no further progress was made and all parental rights were terminated. The implications of these cases for behavior analysis and the effort to reunite and preserve families are discussed.  相似文献   
10.
In the current investigation, a modification was made to the preference assessment described by Pace, Ivancic, Edwards, Iwata, and Page (1985) to predict the effects of stimuli when used in a differential-reinforcement-of-other-behavior (DRO) schedule for 2 clients with severe self-injurious behavior (SIB) and profound mental retardation. Based on the results of the preference assessment, three types of stimuli were identified: (a) high-preference stimuli associated with high rates of SIB (HP/HS), (b) high-preference stimuli associated with relatively lower rates of SIB (HP/LS), and (c) low-preference stimuli associated with low rates of SIB (LP/LS). Consistent with the results of the preference assessment, the DRO schedule with HP/HS stimuli resulted in increased SIB, and the DRO schedule with LP/LS stimuli resulted in no changes in SIB. HP/LS stimuli were demonstrated reinforcers but did not result in a change in SIB when used in a DRO schedule. Thus, the stimulus preference assessment may be useful clinically in some situations for predicting both the beneficial and the negative side effects of stimuli in DRO procedures.  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