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   77158篇
  免费   3138篇
  国内免费   50篇
  80346篇
  2020年   856篇
  2019年   1070篇
  2018年   1520篇
  2017年   1509篇
  2016年   1618篇
  2015年   1090篇
  2014年   1345篇
  2013年   6491篇
  2012年   2443篇
  2011年   2589篇
  2010年   1540篇
  2009年   1603篇
  2008年   2310篇
  2007年   2280篇
  2006年   2037篇
  2005年   1812篇
  2004年   1795篇
  2003年   1613篇
  2002年   1682篇
  2001年   2489篇
  2000年   2429篇
  1999年   1849篇
  1998年   927篇
  1997年   825篇
  1996年   761篇
  1995年   765篇
  1993年   745篇
  1992年   1477篇
  1991年   1400篇
  1990年   1368篇
  1989年   1255篇
  1988年   1236篇
  1987年   1173篇
  1986年   1182篇
  1985年   1265篇
  1984年   1022篇
  1983年   896篇
  1982年   733篇
  1979年   1035篇
  1978年   764篇
  1976年   716篇
  1975年   869篇
  1974年   1001篇
  1973年   984篇
  1972年   877篇
  1971年   767篇
  1969年   718篇
  1968年   904篇
  1967年   859篇
  1966年   775篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
191.
Children's perception of scale and contour in melodies was investigated in five studies. Experimental tasks included judging transposed renditions of melodies (Studies 1 and 3), discriminating between transposed renditions of a melody (Study 2), judging contour-preserving transformations of melodies (Study 4), and judging similarity to a familiar target melody of transformations preserving rhythm or rhythm and contour (Study 5). The first and second studies showed that young children detect key transposition changes even in familiar melodies and they perceive similarity over key transpositions even in unfamiliar melodies. Young children also are sensitive to melodic contour over transformations that preserve it (Study 5), yet they distinguish spontaneously between melodies with the same contour and different intervals (Study 4). The key distance effect reported in the literature did not occur in the tasks of this investigation (Studies 1 and 3), and it may be apparent only for melodies shorter or more impoverished than those used here.  相似文献   
192.
This study examined matching-to-sample procedures that might result in the emergence of conditional behavior never explicitly taught. Subjects were preschool children. Two pictures were displayed as comparisons on every trial, and samples were spoken words. In baseline training preceding each of three experiments, children learned to select pictures of a dog, a table, and a banana in response to their spoken English names. Thereafter, probe trials displayed novel comparisons with baseline comparisons: one novel comparison was displayed with the dog and another with the table. The three experiments differed primarily in the nature of the samples presented on probe trials. In Experiment 1, probe samples were novel words, "JAIJAI" and "BREEL." On the probes, each of seven subjects reliably selected the novel comparisons, apparently "excluding" the familiar ones. In Experiment 2, probe samples were from the subjects' baseline. On one probe, for example, the sample was "TABLE," and the subject had to choose either the dog or the novel picture. Exclusion was logically possible because the dog had always before been incorrect in the presence of "TABLE." Under these conditions, however, only two of nine children excluded reliably. In Experiment 3, probe samples were words that had never been samples on any matching-to-sample trial, but that had controlled the children's behavior in other settings. On one probe, for example, the sample was "PENCIL," and the subject had to choose either the dog or a novel picture. Subjects virtually always excluded the former and selected the latter. Unreliable exclusion in Experiment 2, therefore, apparently resulted because the probe samples had previously served also as samples on baseline trials. Spontaneous verbalizations recorded during probing provided further data consistent with this interpretation. The study helps to define variables controlling exclusion performances by showing that such performances are more likely to occur if the sample has no prior experimental history.  相似文献   
193.
Evidence increasingly links a high-fat, low-fiber diet to coronary heart disease and certain site cancers, indicating a need for large-scale dietary change. Studies showing the effectiveness of particular procedures in specific settings are important at this point. The present study, using an A-B-A-B design and sales data from computerized cash registers, replicated and extended previous work by showing that inexpensive prompts (i.e., signs and fliers) in a national fast-food restaurant could increase the sales of salads, a low-fat, high-fiber menu selection. Suggestions also are made pertinent to more widespread use of the procedures.  相似文献   
194.
This study investigated the effect of television food commercials on children's self-control within a resistance to temptation paradigm. Commercial type, food stimulus type, and the child's sex provided the three independent variables in a 4 × 4 × 2 factorial design. Behavioral and self-report indices of temptation and control were measured. Children were significantly more tempted to transgress for the low-nutrition food, regardless of the commercial shown. Sex differences in reported degree of temptation were found. However, the television commercials did not affect the children's latency to transgress.  相似文献   
195.
Celiac-Sprue Disease, also referred to as Non-Tropical Sprue, is a dietary disease. Celiac-Sprue patients were asked to complete a questionnaire regarding the effect of dietary restrictions on participation in the Passover meal and reception of Communion. A pilot study suggested that subjects made changes in their religious practices because of dietary restrictions. A second, more detailed survey, was performed in which 58 subjects participated and 14 religions were represented. The results indicated that many subjects made changes in their religious practices (p less than .01), made changes on their own initiative (p less than .01), or violated diet prescribed for the disease under the religious setting versus other settings (p less than .05).  相似文献   
196.
Using a multi-trial, free-recall paradigm (Rey Auditory-Verbal Learning Test; Lezak, 1983), the acquisition and retention by learning disabled (LD) young adults with a Halstead Impairment Index less than or equal to 0.3 (low LD) or greater than or equal to 0.4 (high LD) was compared with that of nondisabled and head-injured (HI) young adults. Significant group differences, particularly during the last three acquisition trials, confirmed the effectiveness of this method in revealing subtle learning and retention deficits. Analyses of Trial 1 recall showed group differences in the prerecency but not the recency portion of the serial position curve, thus implicating long-term but not short-term memory differences between the groups. Analyses of pair frequency (Sternberg & Tulving, 1977) data showed that the three clinical groups had difficulty organizing the to-be-learned material for effective retrieval. Following an interpolated task, retention was poorer for the clinical groups than for the nondisabled and varied inversely with the degree of neuropsychological impairment. Finally, during retention, the nondisabled and low LD groups retained and used the list organization established during acquisition whereas the high LD and HI groups did not.  相似文献   
197.
In this study I explored whether the degree of anticipation/habituation (undershooting/overshooting) varies with the dimension to be localized, when the method of adjustment is used in space localization. In this study, undershooting occurred for both the vertical (Group 1) and the horizontal (Group 2) dimensions, but was significant only for verticality. The magnitude of undershooting observed for verticality was significantly greater than that for horizontality. A secondary issue regarding the possible relationship between spatial category width and undershooting/overshooting was examined. It was hypothesized that greater degree of spatial category width would be associated with greater undershooting. The opposite was found: Spatial category width was negatively related to undershooting. Finally, within each group, very high consistency of magnitude of spatial category width was observed (rs greater than .90), despite the fact that spatial category width showed shrinkage over the course of the study.  相似文献   
198.
This paper emphasizes the impact of the setting, space, and general physical properties of the clinic upon the difficult patient's profound neediness and absence of inner regulatory structure. Moreover, the clinic's administrative style and requirements often related to fiscal restraints, demands for accountability for both how funds are spent and treatment outcome, all impinge upon the patient. Humanizing clinics so they have the capacity for psychotherapeutic holding and provision of safety for difficult patients are discussed in detail in this contribution.  相似文献   
199.
Tobacco, alcohol, and drug use are problems for American-Indian people. We reviewed these problems and the explanations for them and described a bicultural competence skills approach for preventing substance abuse with American-Indian adolescents. Data from a study of that approach suggest its efficacy with American-Indian youth. At posttest and a 6-month follow-up, American-Indian subjects who received preventive intervention based on bicultural competence skills concepts improved more than did American-Indian subjects in a no-intervention control condition on measures of substance-use knowledge, attitudes, and interactive skills, and on self-reported rates of tobacco, alcohol, and drug use. Our findings have implications for future substance-abuse prevention research with American-Indian people.  相似文献   
200.
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