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   24220篇
  免费   2503篇
  国内免费   1278篇
  28001篇
  2024年   93篇
  2023年   546篇
  2022年   420篇
  2021年   539篇
  2020年   1091篇
  2019年   1134篇
  2018年   999篇
  2017年   1045篇
  2016年   912篇
  2015年   731篇
  2014年   879篇
  2013年   2528篇
  2012年   565篇
  2011年   746篇
  2010年   599篇
  2009年   774篇
  2008年   899篇
  2007年   938篇
  2006年   955篇
  2005年   826篇
  2004年   718篇
  2003年   617篇
  2002年   531篇
  2001年   389篇
  2000年   360篇
  1999年   318篇
  1998年   252篇
  1997年   218篇
  1996年   207篇
  1995年   206篇
  1994年   169篇
  1993年   148篇
  1992年   138篇
  1991年   85篇
  1990年   76篇
  1989年   72篇
  1987年   68篇
  1985年   512篇
  1984年   585篇
  1983年   474篇
  1982年   574篇
  1981年   550篇
  1980年   561篇
  1979年   513篇
  1978年   553篇
  1977年   448篇
  1976年   422篇
  1975年   345篇
  1974年   313篇
  1973年   255篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
One-hundred and twenty-five families in the Medicaid Early Periodic Screening, Diagnosis and Treatment Program were assigned to one of five treatments to encourage parents to obtain health care service following the dental screening of their children: (a) a control procedure, in which parents were given a dentist's name; (b) a multiple contact procedure, in which parents received a postcard and two telephone call reminders; (c) a problem-solve procedure, in which a social worker aide conducted a brief session with the parent; (d) an incentive procedure, in which parents selected among four gifts that were contingent on seeking care; (e) an incentive + problem-solve procedure, in which the latter two treatments were combined. The multiple contact, incentive, and incentive + problem-solve techniques were significantly more effective in initiating dental visits than the control procedures. Families assigned to the intensive strategies were most likely to complete treatment. A cost-efficiency analysis showed the multiple contact technique to be a low-cost and highly effective procedure.  相似文献   
942.
This study describes and evaluates a reinforcement program in which parents earned lottery tickets and won prizes for the progress made by their handicapped children during home-based intervention. An ABAB reversal design replicated across three families was used to assess the effects of the lottery on the children's mastery of language skills. Results showed that the reinforcement of the parents for training accomplishments, as indexed by their children's achievements, produced clinically significant increases in the children's progress when compared with the children's progress under the routine supportive practices of the baseline condition. The implications of the findings for parent training programs in general are discussed.  相似文献   
943.
Eighth and tenth grade students were asked to study and recall a list of paired associates. The word pairs were available either throughout an 8 sec per word study period or only at the beginning and were composed of either high frequency or low frequency words. After recall, students were asked to indicate which of several study strategies they had used with each word pair (read pair carefully, rehearsal, visual elaboration, verbal elaboration). In addition, they were asked which of these strategies would have had the best effect on recall. Knowledge of appropriate memory strategies (metamemory) was positively related to strategy use, and strategy use was positively related to recall performance at both ages. Improved performance with materials available throughout study and with high frequency word pairs was explained by increased use of elaborative strategies. Age differences in performance were explained by increased strategy effectiveness. These results are discussed in relation to changing relationships among metamemory, strategy use, and performance with age.  相似文献   
944.
Age differences in when (i.e., at input or output) children organize information for recall were investigated in terms of a model specifying that information organized at input is more resistant to forgetting over time than information not organized at input. In Experiment 1, recall of items from categorically related and unrelated lists was assessed either immediately or after a 4-min delay. For 9-year-olds, the effect of delay was comparable for the related and unrelated lists, indicative of spontaneous organization at time of output. In contrast, 13-year-olds showed a significantly smaller delay effect with related than with unrelated lists, indicative of spontaneous organization at time of input. Experiments 2 and 3 demonstrated that, for 9-year-olds, high levels of clustering in and of themselves do not eliminate effects of delayed testing characteristic of output organization, and that when 9-year-olds are biased to organize information at input, delay effects are reduced only when measures are taken to ensure that all the category labels are retrieved.  相似文献   
945.
Three experiments were conducted with the Tower of Hanoi task to assess problem solving ability in 6-, 7-, 8-, and 10-year-old nonretarded children and mentally retarded young adults of varying maturational ages. In Experiment 1 we gradually reduced the number of moves required for solution until subjects could solve the 3-disk tower-ending problem. Although all groups experienced difficulty with the standard 7-move problem, all but the trainable retarded group readily solved the 6-move problem. The trainable group did not reach a comparable level of success until the 4-move problem. On the 7-move problem the retarded groups performed at the level of nonretarded groups that were maturationally 112 to 3 years younger. An analysis of first moves indicated that subject groups differed in the strategies they used to solve the problems. In Experiment 2, practice effects were ruled out as a source of the superior performance on the 6- than on the 7-move problem. In Experiment 3, 7- and 10-year-old nonretarded children and mentally retarded young adults did not differ on 5-move problems in which configuration of the goal states was varied. A comparison of all 5-move problems judged to have the same depth of search requirements indicated that the tower-ending problems were significantly easier to solve than the partial-tower-ending problems, which in turn were easier than the flat-ending problems. A limited depth of search capacity sets boundaries on the use of sophisticated strategies and, to a large extent, accounts for the retarded groups' maturational lag.  相似文献   
946.
Thirty-six 3- and 4-year-old children were given a battery of six metalinguistic tasks and two measures of language development: the Peabody Picture Vocabulary Test and a sentence comprehension test. The results clearly showed that the majority of preschoolers were able to make at least some metalinguistic judgments, and that metalinguistic performance improved with age. Furthermore, overall performance on the metalinguistic tasks was significantly correlated with each language measure when the effects of age were partialed out. In contrast, the correlation between age and metalinguistic performance was not significant once the effects of both language measures were partialed out. These data demonstrate that preschoolers' metalinguistic abilities are more extensive than has been previously acknowledged, and that they are closely tied to other aspects of language development at this time.  相似文献   
947.
The hypothesis-testing behavior of kindergarten children in discrimination learning was studied in a factorial design with two temporal placements of introtact probes (pretrial and posttrial) and two types of pretraining (unidimensional and multidimensional). Pretrial probes consisting of a request for the child's current hypothesis were administered in a conventional manner at the beginning of each trial with the stimuli in view and prior to the choice response. Posttrial probes were administered also with the stimuli in view, but after the choice response had occurred and feedback information had been provided. Learning-to-learn experience in solving three pretraining problems was given either with unidimensional simultaneous problems or with more complex multidimensional problems like the criterion tasks. The results indicated that posttrial probes produced superior local consistency, win-stay, and lose-shift probabilities, relative to pretrial probes, for both types of pretraining. Posttrial probes, however, facilitated learning and the testing of valid hypotheses only for multidimensional pretraining. These results are consistent with the hypothesis that posttrial probes constrain the child to be locally consistent and therefore improve short-term efficiency in hypothesis testing under both pretraining conditions. However, posttrial probes produce an improvement in long-term efficiency, and therefore in learning, only when other components of a successful strategy are acquired as in multidimensional pretraining.  相似文献   
948.
Previous research has demonstrated that salient information is overrepresented in causal attributions. Two experiments were conducted to investigate potential mediators for this effect and to make a case for the use of structural models in explanations of process. Two mediators were considered: enhanced visual recall of salient stimuli and exaggerated schema-relevant recall of salient stimuli. Although analyses of variance supported the visual recall model, structural analyses demonstrated its implausibility. Analyses of variance and structural models revealed that schema-relevant recall, that is, information seen as representative of causal influence, is a plausible mediator; this was particularly true of relevant visual information. Results suggest that salience effects (S. E. Taylor & S. T. Fiske in L. Berkowitz (Ed.), Advances in experimental social psychology (Vol. 11). New York: Academic Press, 1978) are due to: (a) the attentional advantage of inherently salient visual events and (b) the influence of stored visual and nonvisual schema-relevant information on causal judgments.  相似文献   
949.
The present study tested the idea that the amount of effort expended in task performance is a function of the amount of uncertainty in one's ability level the resulting outcomes are expected to reduce. Two determinants of expected uncertainty reduction were manipulated: prior uncertainty about one's ability level and the diagnosticity of the task. Subjects first performed an initial task and then received fictitious feedback to manipulate their prior uncertainty. To induce low uncertainty, the feedback implied that the subjects are highly likely to have either low, intermediate, or a high level of ability. To induce high uncertainty, the feedback implied that the various ability levels were equally probable. Subjects then performed a task whose perceived diagnosticity regarding the ability under consideration was varied. As expected, subjects who were highly uncertain about their ability level performed better than subjects who were relatively certain they possessed either low, intermediate, or a high level of ability. Performance also improved with task diagnosticity, and the effect of task diagnosticity on performance was more pronounced when prior uncertainty was high than when it was low. Past research on the relationship between prior feedback and subsequent performance was discussed in light of the present results and a self-assessment model of achievement behavior.  相似文献   
950.
Two studies examined the pattern of reasons given for rejecting dates and how they reflect concerns of the rejector. Study One examined retrospective accounts of rejection. Rejectors often reported withholding the reason for rejection from the rejected person. A content analysis of the reasons communicated to rejected persons was performed using Weiner's (Journal of Educational Psychology, 1979, 71, 3–25) attributional dimensions of locus, controllability, and stability. The stated reasons were found to be primarily impersonal, uncontrollable, and unstable. Study Two examined rejectors' willingness to communicate certain types of reasons. The true, privately held reasons for turning down dates were systematically varied as to locus, controllability, and stability. The types of reasons subjects offered to rejected persons were consistent with Study One. Reasons for refusal were less likely to be revealed when they related to the appearance or personality of the rejected person, particularly when the personal reasons were uncontrollable and stable. Rejectors were not as forthright when they controlled the reason for rejection as when they lacked control. The rejectors' actions were interpreted as being self-presentational, reflecting concerns about rejected persons' emotional reactions, expectancies for the future of the relationship, and blame for rejection.  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