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   657篇
  免费   42篇
  国内免费   1篇
  2024年   3篇
  2023年   8篇
  2022年   8篇
  2021年   15篇
  2020年   28篇
  2019年   20篇
  2018年   43篇
  2017年   31篇
  2016年   46篇
  2015年   19篇
  2014年   26篇
  2013年   63篇
  2012年   35篇
  2011年   39篇
  2010年   31篇
  2009年   15篇
  2008年   26篇
  2007年   36篇
  2006年   21篇
  2005年   18篇
  2004年   23篇
  2003年   16篇
  2002年   15篇
  2001年   12篇
  2000年   9篇
  1999年   9篇
  1998年   7篇
  1997年   7篇
  1996年   3篇
  1995年   3篇
  1992年   3篇
  1991年   5篇
  1990年   4篇
  1989年   6篇
  1988年   2篇
  1987年   2篇
  1985年   5篇
  1983年   4篇
  1981年   3篇
  1980年   2篇
  1979年   4篇
  1975年   3篇
  1974年   2篇
  1972年   2篇
  1971年   1篇
  1969年   1篇
  1968年   2篇
  1967年   3篇
  1966年   5篇
  1965年   1篇
排序方式: 共有700条查询结果,搜索用时 15 毫秒
571.
An ongoing problem in the genetics clinic is the calculation of inbreeding coefficients and recurrence risks for complex pedigrees, particularly when multiple loops are present. Although the Human Genome Project promises information about more of our genes in the foreseeable future, the actual assignment of disease status to specific loci will continue at a slower pace, so that accurate risk calculations are needed. In the past few months several families with consanguinity were referred to us to confirm the calculations performed by the genetic counselor, and we became aware of some confusion in the field. We present here both (a) a clarification of definitions and concepts and (b) a review of how to perform the calculations, for several quantities (coefficient of relationship, coefficient of inbreeding, coefficient of kinship, and recurrence risk), in complex pedigrees. We discuss the availability of computer algorithms to assist in these calculations, and we encourage counselors to call on a reliable computer program for any but the simplest cases. At the same time, we reiterate our belief that computer algorithms do not relieve the counselor of the responsibility of knowing what to calculate and when.  相似文献   
572.
573.
574.
Forty five subjects who experienced chronic, occupational pain of the upper limbs were randomly assigned to one of three conditions; individual cognitive-behaviour therapy (ICBT), group cognitive-behaviour therapy (GCBT) and WLC. Significant benefits were found for both ICBT and GCBT on measures of anxiety, depression, coping strategies, impact on daily living, pain and distress caused by pain. These gains were not evident in the WLC and were maintained at the 6 month follow-up Minimal difference was found between ICBT and GCBT on measures of pain and psychopathology, although client evaluation ratings at the end of treatment favoured ICBT.  相似文献   
575.
576.
Fourteen musicians who reported a history of pain in the upper limb associated with the playing of their instruments were compared with a sample of pain-free musicians, matched for age, sex and musical instrument. Four tasks were presented in random order and included neutral, general stressor, personal stressor and pain stressor tasks. Ratings of stressfulness and recordings of skin conductance level confirmed the effectiveness of the experimental manipulations for both subject groups. No differences were found between groups or tasks for frontalis surface electromyograph (EMG) activity. Evidence was found, however, of EMG elevation in flexor and trapezius muscles on the pain side for the pain subjects, in response to the task involving recall of a pain experience. This elevation was not found for the pain-free controls or for other stressor tasks, although some elevation in response to the pain stressor task was found for pain subjects in the trapezius muscles of the non-pain side. The duration of return to baseline of EMG following the pain stressor task was found to be extended in pain subjects for the trapezius, but not for the flexor muscles of the pain side. The findings suggest that site-specific muscle hyper-reactivity may play a role in the development and maintenance of occupational upper limb pain in musicians.  相似文献   
577.
Questionnaires were developed to assess the concept of workaholism, defined in terms of high scores on measures of work involvement and driveness and low scores on a measure of enjoyment of work, and to contrast this profile with work enthusiasm, defined as high work involvement and enjoyment and low driveness. Additional scales were devised to test several predictions about the correlates of workaholism. A test battery including these scales was given in a mail survey to a national sample of male (n = 134) and female (n = 157) social workers with academic positions. The psychometric properties of the scales are described. Cluster analyses for each sex revealed groups who corresponded to the workaholic and work enthusiast profiles as well as several other profiles. As predicted, workaholics were higher than work enthusiasts (among other groups) on measures of perfectionism, nondelegation of responsibility, and job stress. They were also higher on a measure of health complaints. Investigations are being initiated to determine the association of workaholism and other score profiles with objectively diagnosed cardiac disorders and with measures of occupational performance.  相似文献   
578.
579.
Middle- and lower-class children who had been treated by E in a warm or aloof manner were given a discrimination learning task under one of six conditions forming a 3 × 2 design: three reinforcement types (Verbalintoned, Verbal-nonintoned, or Symbolic) and reinforcement for correct or incorrect responses. In accordance with Zigler's valence theory of social reinforcement, lower-class girls and middle-class children of both sexes tended to perform better when they had previously received warm treatment. No significant differences among the three types of reinforcers occurred in either SE group, thus failing to support the implications of several theories about the relative effectiveness of social and nonsocial reinforcers and tonality factors related to SES.  相似文献   
580.
Ian Spence 《Psychometrika》1972,37(4):461-486
As a consequence of the complexity of the iterative optimum seeking procedures used by practical nonmetric multidimensional scaling algorithms, many of their computational properties have not been well understood. In particular, the following questions are of interest: (a) from the user's point of view, are there significant differences between alternative available programs, (b) are suboptimal solutions frequently encountered, and how does this depend on the characteristics of the algorithm? Using Monte Carlo techniques to generate dissimilarity matrices with known underlying configurations, Kruskal's M-D-SCAL, Guttman-Lingoes' SSA-I, and Young-Torgerson's TORSCA-9 programs were compared. It was found: (a) that differences between the solutions obtained by the algorithms were typically so small as to be of little practical importance, (b) deviant solutions were occasionally produced by each of the algorithms, but most often by M-D-SCAL, and furthermore, most frequently in one dimension. The likelihood of being trapped in a nonoptimal position is reduced by a good choice of initial configuration, and also possibly by constructing the iterative process to favor the possibility of stepping over small local depressions when far from the location of the optimum. The conclusions of this study are based on a total of 2160 scaling solutions.  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