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   3342篇
  免费   395篇
  国内免费   180篇
  3917篇
  2024年   9篇
  2023年   71篇
  2022年   46篇
  2021年   82篇
  2020年   168篇
  2019年   205篇
  2018年   157篇
  2017年   210篇
  2016年   179篇
  2015年   132篇
  2014年   135篇
  2013年   595篇
  2012年   106篇
  2011年   134篇
  2010年   86篇
  2009年   154篇
  2008年   170篇
  2007年   142篇
  2006年   119篇
  2005年   134篇
  2004年   107篇
  2003年   94篇
  2002年   102篇
  2001年   97篇
  2000年   60篇
  1999年   39篇
  1998年   50篇
  1997年   44篇
  1996年   31篇
  1995年   58篇
  1994年   21篇
  1993年   11篇
  1992年   15篇
  1991年   9篇
  1990年   4篇
  1989年   8篇
  1988年   11篇
  1985年   10篇
  1984年   17篇
  1983年   12篇
  1982年   6篇
  1981年   8篇
  1980年   12篇
  1979年   14篇
  1978年   8篇
  1977年   9篇
  1976年   5篇
  1975年   6篇
  1974年   5篇
  1973年   4篇
排序方式: 共有3917条查询结果,搜索用时 15 毫秒
51.
Therapists and parents were given vignettes describing the behavioural and emotional difficulties of two nine-year-old children and were asked to rate the importance of a number of possible explanations for such difficulties. Broad agreement was found between parents and therapists, but also there were a number of significant differences. Parents endorsed more child centered explanations and put greater emphasis on physical and developmental factors, while therapists endorsed relationships factors and saw the beliefs of other family members as important. Therapists who were parents showed a pattern of responses that lay between those of parents and non-parent therapists.  相似文献   
52.
Individual and institutional conflict of interests in biomedical research have becomes matters of increasing concern in recent years. In the United States, the growth in relationships — sponsored research agreements, consultancies, memberships on boards, licensing agreements, and equity ownership — between for-profit corporations and research universities and their scientists has made the problem of conflicts, particularly financial conflicts, more acute. Conflicts can interfere with or compromise important principles and obligations of researchers and their institutions, e.g., adherence to accepted research norms, duty of care to patients, and open exchange of information. Disclosure is a key component of a successful conflict policy. Commitments which conflict with a faculty member's primary obligations to teaching, research, administrative responsibilities, or patient care also need attention. Institutional conflict of interests present different problems, some of which are discussed in an analysis of an actual problem posed by two proposed clinical trials. This paper is adapted from a lecture presented to a Symposium on Scientific Integrity, Warsaw, Poland, 23 November 1995. Daniel Steiner was Vice-President and General Counsel of Harvard University (1972–92) and in that capacity became familiar with conflict of interest issues. He is currently Counsel to the Boston law firm. Ropes and Gray, and is Adjunct Lecturer in Public Policy at the John F. Kennedy School of Government. Harvard University.  相似文献   
53.
This article reports of the activities of the working group, Ethics & Engineers, of the Royal Flemish Society of Engineers. More particularly, the ethical problems that engineers face in the preparation of an environmental report are illuminated. Irrespective to which party the engineer belongs, he or she is confronted with the difficult weighting of his or her personal interest, the interests of private companies and last but not least the common good. It is argued that the implementation of a code of ethics and the introduction of courses on engineering ethics into the education of engineers would strengthen the engineer in the fulfilment of his vocation. Dirk Holemans is a bio-engineer preparing a doctoral thesis on the social responsibility of engineers, Herman Lodewyckx teaches ethics and has research interests in professional and applied ethics.  相似文献   
54.
对听觉条件下中文字词劣效果的问题进行了实验考察,结果发现:在文章听点作业中,被试对高、低频目标字词语音的正误判断量存在着显著性差别,前者较后者成绩差,表现出字词劣效果的现象;在单字词的听点作业中,未发现被试对高、低频目标字词语音正误判断量方面的显著性差别;无论在文章还是单字词的听点作业中,被试对高、低频目标字词语音的正误判断量均比较低下,表明语音知觉的范畴性特征对字词语音的辩认准确性具有较大影响。  相似文献   
55.
The meaning and properties of a commonly used index of reliability, S/L,were examined critically. It was found that the index does not reflect any conventional concept of reliability. When used for an identical behavioral observation session, it is not statistically correlated with other reliability indices. Within an observation session, the standardizing measure of Lis beyond the control of the investigator. Furthermore, the reason for the choice of Las the standard is unclear. The role of chance agreement in S/Lis not known. The exact interpretation of the index depends on which observer reports L.Overall the conceptual and mathematical meaning of S/Lis dubious. It is suggested that the S/Lindex should not be used until its nature is shown to be a measure of reliability. Other approaches such as the intraclass correlations and generalizability coefficients should be used instead.The authors are indebted to Johnny Matson for his critique of an earlier version of this paper.  相似文献   
56.
57.
58.
Weight and height data from two studies were recomputed, and original data were computed using a Weight Index formula that accounts for the interaction of actual weight/height changes in growing children and compares this ratio with that of normed weight/height ratios for equal-aged children. Recomputing the data of one study showed that the Weight Index is a more sensitive procedure for assessing long-term behavioral treatment of obesity for girls than weight alone. Recomputing the data of a second study showed that the Weight Index formula is consistent for boys and girls and is a more sensitive procedure for assessing long-term effects of a variety of medical treatments for obesity than the Ponderal Index or weight alone. Computation of the data for 17 “normal” children in a preschool class showed a zero Weight Index score before and after a six-month interval elapsed without treatment. The procedure may be useful in assessing ponderosity or anorexia over intervals of six months or more with growing children or difference between actual and normed weight over shorter intervals.  相似文献   
59.
60.
Two hypotheses were tested about how young children answer questions with the quantifiers all and some: (a) that children use syntactic cues in determining which noun phrase is quantified, and (b) that children evaluate a some-statement as part of evaluating an all-statement. To test these hypotheses, the same group of 60 4- to 7-year-olds were asked four contrasting types of quantitative questions. The results indicated that children can use syntactic cues under some presentation conditions. However, there was no evidence for an asymmetry between the all-and some-questions. A model of how young children might answer quantitative questions was then considered.  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