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   23543篇
  免费   951篇
  国内免费   13篇
  2020年   219篇
  2019年   281篇
  2018年   411篇
  2017年   438篇
  2016年   463篇
  2015年   347篇
  2014年   395篇
  2013年   1910篇
  2012年   696篇
  2011年   720篇
  2010年   428篇
  2009年   407篇
  2008年   588篇
  2007年   613篇
  2006年   533篇
  2005年   502篇
  2004年   476篇
  2003年   479篇
  2002年   482篇
  2001年   769篇
  2000年   746篇
  1999年   561篇
  1998年   235篇
  1997年   220篇
  1996年   248篇
  1992年   475篇
  1991年   453篇
  1990年   443篇
  1989年   411篇
  1988年   432篇
  1987年   393篇
  1986年   404篇
  1985年   408篇
  1984年   340篇
  1983年   302篇
  1982年   217篇
  1981年   228篇
  1979年   362篇
  1978年   267篇
  1977年   240篇
  1975年   308篇
  1974年   368篇
  1973年   382篇
  1972年   300篇
  1971年   288篇
  1970年   284篇
  1969年   255篇
  1968年   357篇
  1967年   314篇
  1966年   291篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
121.
A hardware-and-software system is described that permits musical-bandwidth signal quantization, monophonic or stereophonic, direct to/from hard disk. The system, which uses an IBM AT or compatible, is cost effective and device independent. Software functions allow for automated aural and graphical signal analyses. Perceptual experiments that use contextual, natural-instrument stimuli, and that take advantage of the immediate and random access provided by this system, are described.  相似文献   
122.
This paper describes a method of establishing time intervals at a precision of better than 1 msec, using QuickBASIC 4.0, for running real time experiments on an IBM PC without an 8087 coprocessor. This method is far superior to the TIMER function provided by BASIC, which has a precision of only 110 msec. Also described is an assembly language subroutine that corrects a problem in QuickBASIC 3.0 and QuickBASIC 4.0 to allow proper switching between screens in the CGA text mode for use of the PC as a tachistoscope. A tachistoscope program listing shows how to use the screen subroutine and how to establish intertriai intervals and record reaction times using the timing subroutines.  相似文献   
123.
A computer-controlled system that detects spontaneous activity (locomotion and rearing) and diurnal activity rhythms in small animals is described. Automatic recording of subtotals during test periods provides data about habituation (nonassociative learning). The system is relatively inexpensive to construct. Fabricated from highly reliable circuit components, it provides replicable measures that enable comparisons between different experimental treatments to be made using parametric statistics.  相似文献   
124.
125.
Maternal handling and motor development: an intracultural study   总被引:1,自引:0,他引:1  
Citing a distinction between informal and formal routines used by mothers in handling their infants, we examined formal handling routines, in which the caregiver acts in a pedagogical manner; these routines are widespread in many non-Western countries. We hypothesised that formal handling serves to facilitate gross motor development during early infancy. To examine this hypothesis, the effects of a Jamaican formal handling routine on a broad range of developmental outcomes was examined. Results showed that the effects were specific to early gross motor development and in particular to postural control along the vertical axis of the body. Information is also provided on other aspects of Jamaican child care. It seems that the handling routine forms part of a folk (developmental) medicine system and may serve not only to promote child health but also as a sort of developmental neurological examination.  相似文献   
126.
S Shamai  R B Coambs 《Adolescence》1992,27(108):757-770
This paper evaluates intervention programs in schools using the theoretical framework of the critical sociology of education, and most specifically, the extent to which schools are autonomous from the larger society. Three different types of intervention programs are reviewed: drug abuse prevention, sex education, and programs to change gender stereotypes, all of which were found to have limited effectiveness. Schools appear unable to change behaviors which are prevalent in a culture because they themselves are strongly influenced by that culture, and because adolescents are influenced by forces outside school. To be effective, such interventions would seem to require governmental agencies, community groups, and the media to work with the schools in order to influence the culture and thus produce behavioral changes in individuals.  相似文献   
127.
Differences in school behavior and achievement between students from intact, reconstituted, and single-parent families were analyzed. Students from intact two-parent families had fewer absences and tardies, higher grade point averages, and fewer negative and more positive teacher behavioral ratings than did those from reconstituted and single-parent families.  相似文献   
128.
129.
Neutrality is a central concept within the theory of psychoanalytic technique. We spell out the major controversies in which the concept has become embroiled, and provide a definition that we believe coincides with actual psychoanalytic practice. We discuss its merits and weaknesses, noting also the negative consequences of relying on older definitions. We relate neutrality to the interpretive process, indicating ways interpretation protects neutrality and is made more effective by it. We discuss the complex and controversial relation between neutrality and the analyst's therapeutic intent.  相似文献   
130.
Forty-one nonpsychiatric subjects, 38 probands with schizophrenia, and 99 of their relatives were studied. Oculomotor functioning was bimodally distributed for probands and relatives. Oculomotor dysfunction was not present in all families with a schizophrenic proband. In those families in which it was present, there were significant phenotypic correlations between oculomotor functioning and schizophrenia-related characteristics. The patterns of familial resemblance in the families in whom oculomotor dysfunction was present were consistent with nonadditive genetic variance contributing both to oculomotor dysfunction and to the relationship between oculomotor dysfunction and clinical symptoms. These results suggest that schizophrenia may be etiologically heterogeneous and that oculomotor dysfunction may help to identify nonadditive genetic variance for this disorder.  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