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   43417篇
  免费   1544篇
  国内免费   16篇
  44977篇
  2019年   504篇
  2018年   624篇
  2017年   614篇
  2016年   704篇
  2015年   520篇
  2014年   654篇
  2013年   3374篇
  2012年   1134篇
  2011年   1220篇
  2010年   753篇
  2009年   791篇
  2008年   1096篇
  2007年   1056篇
  2006年   978篇
  2005年   881篇
  2004年   869篇
  2003年   846篇
  2002年   871篇
  2001年   1172篇
  2000年   1205篇
  1999年   842篇
  1998年   469篇
  1997年   412篇
  1992年   748篇
  1991年   746篇
  1990年   766篇
  1989年   739篇
  1988年   682篇
  1987年   668篇
  1986年   706篇
  1985年   751篇
  1984年   619篇
  1983年   595篇
  1982年   447篇
  1981年   486篇
  1980年   408篇
  1979年   701篇
  1978年   540篇
  1977年   447篇
  1976年   438篇
  1975年   625篇
  1974年   702篇
  1973年   742篇
  1972年   637篇
  1971年   607篇
  1970年   550篇
  1969年   595篇
  1968年   728篇
  1967年   717篇
  1966年   655篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
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   
112.
The purpose of this study was to test the hypothesis that social demand could substantially affect reports of self-monitored blood glucose (BG) in adolescents with insulin-dependent diabetes mellitus. Of 34 patients initially enrolled in the study, 10 were excluded because they did not bring any BG records with them to an outpatient clinic appointment. The remaining 24 patients were randomly assigned to either a low or high social demand condition that provided instructions for monitoring of BG for the week following the appointment. The subjects' BG records were quantified to provide frequency of measurement and mean reported BG for the week prior to and after the clinic visit. Five subjects did not return their BG records for the week following the intervention. The analyses were therefore based on the 19 subjects from whom complete records were obtained. The 12 subjects in the low social demand group and 7 subjects in the high social demand group were equivalent with regard to age, duration of diabetes, socioeconomic status, and glycosylated hemoglobin. Frequency of BG measurement was similar in both groups during both weeks. The mean BG value reported in the week prior to intervention was similar for the groups. However, analyses of the post-intervention BGs revealed that subjects in the low-demand group reported significantly higher BGs compared to pre-intervention and to subjects in the high-demand group. These findings suggest that self-monitoring and reporting of BG is a social behavior that is affected by the demand characteristics of the interpersonal patient-health provider relationship. Because optimal treatment planning for individuals with diabetes requires accurate BG records, care must be taken to interpret them in light of the social demand characteristics associated with clinical assessment.  相似文献   
113.
We examined the functional role of verbalizations in the generalization of self-instructional training with preschoolers. Children learned to overtly self-instruct during classroom work periods prior to covert training. Data were collected on children's acquisition of verbal regulation during training and on overt use of self-instructions in the classroom generalization setting. Results of a multiple baseline design across subjects indicated that treatment effects were evident in the training setting but did not generalize to the classroom until children were emitting overt self-instructions in the classroom itself. The production of self-verbalizations in the generalization setting was related to changes in correct responding, on-task behavior, and efficiency in completing academic work.  相似文献   
114.
Behavioral momentum refers to the tendency for behavior to persist following a change in environmental conditions. The greater the rate of reinforcement, the greater the behavioral momentum. The intervention for noncompliance consisted of issuing a sequence of commands with which the subject was very likely to comply (i.e., high-probability commands) immediately prior to issuing a low-probability command. In each of five experiments, the high-probability command sequence resulted in a “momentum” of compliant responding that persisted when a low-probability request was issued. Results showed the antecedent high-probability command sequence increased compliance and decreased compliance latency and task duration. “Momentum-like” effects were shown to be distinct from experimenter attention and to depend on the contiguity between the high-probability command sequence and the low-probability command.  相似文献   
115.
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   
116.
The effect of negative, positive, or neutral feedback on a rotary pursuit task as a function of the subject's depressed or elated mood was ascertained. Specifically, the self-schema hypothesis was examined. Ninety female volunteers, ranging in age from 18 to 25 years, participated. They were randomly assigned to one of eight conditions based on depressed or elated mood states, elicited by Velten's (1968) mood induction procedure, and feedback. A control group received no feedback and was not subjected to a mood inducing treatment. Baseline measures and changes in mood were determined by the Multiple Adjective Affective Checklist (MAACL). Bogus feedback was offered after all but one of the trials. The subjects' mood changed significantly during the mood-inducing treatment. For motor performance, partial support was lent to self-schema. Elated and depressed subjects performed best under positive and negative feedback, respectively. The effects, however, were temporary.  相似文献   
117.
118.
119.
120.
Through school-sponsored health fairs, 398 adolescents (153 males and 245 females) between the ages of 14 and 18 completed a questionnaire on their compliance with six of the U.S. Dietary Guidelines. Results indicated that adolescents report highest compliance on "eat a variety of foods" and "eat foods with adequate starch and fiber." Conversely, they indicated low compliance on "reduce sugar intake" and "reduce fat, saturated fat and cholesterol intake." Sex differences were noted on two dietary guidelines. Females reported lower compliance with respect to "maintain desirable body weight." Males, on the other hand, reported lower compliance than females on "reduce salt intake." Given the fact that the dietary guidelines of "reduce fat, saturated fat and cholesterol," "maintain desirable body weight," and "reduce salt intake" are all aimed at reducing cardiovascular risk, the low compliance reported by adolescents may have long-range health implications.  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