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   1205篇
  免费   24篇
  国内免费   12篇
教育   783篇
科学研究   218篇
各国文化   23篇
体育   98篇
综合类   5篇
文化理论   6篇
信息传播   108篇
  2023年   8篇
  2022年   7篇
  2021年   26篇
  2020年   30篇
  2019年   41篇
  2018年   47篇
  2017年   72篇
  2016年   44篇
  2015年   36篇
  2014年   48篇
  2013年   176篇
  2012年   46篇
  2011年   47篇
  2010年   50篇
  2009年   37篇
  2008年   44篇
  2007年   39篇
  2006年   30篇
  2005年   33篇
  2004年   19篇
  2003年   25篇
  2002年   25篇
  2001年   26篇
  2000年   24篇
  1999年   27篇
  1998年   4篇
  1997年   6篇
  1996年   12篇
  1995年   11篇
  1994年   8篇
  1992年   12篇
  1991年   13篇
  1990年   7篇
  1989年   5篇
  1987年   10篇
  1986年   8篇
  1985年   17篇
  1984年   12篇
  1983年   12篇
  1982年   10篇
  1981年   5篇
  1980年   7篇
  1979年   5篇
  1978年   7篇
  1977年   4篇
  1975年   10篇
  1974年   6篇
  1973年   7篇
  1971年   7篇
  1970年   4篇
排序方式: 共有1241条查询结果,搜索用时 31 毫秒
11.
This paper addresses a dynamic portfolio investment problem. It discusses how we can dynamically choose candidate assets, achieve the possible maximum revenue and reduce the risk to the minimum level. The paper generalizes Markowitz's portfolio selection theory and Sharpe's rule for investment decision. An analytical solution is presented to show how an institutional or individual investor can combine Markowitz's portfolio selection theory, generalized Sharpe's rule and Value-at-Risk(VaR) to find candidate assets and optimal level of position sizes for investment (dis-investment). The result shows that the generalized Markowitz's portfolio selection theory and generalized Sharpe's rule improve decision making for investment.  相似文献   
12.
This investigation presents a framework for understanding and also to test the efficacy of Social Work intervention on the well being of the white collared employee (industrial employee) and his/her family. A comprehensive and intensive personal- family exploration was done to uncover the relatedness of seemingly disparate areas of the clients lives. A total of 80 executives (industrial employees) served as subjects. A baseline assessment was done using structured, standardized interview-schedules/questionnaires. The results of the study can be enumerated as follows: After the Social Work intervention, the executives in occupational profile, there were significant changes in Role perception, overload, role conflict, low status and poor peer relations. In coping strategies there was significant improvement in sub-scales like problem solving and unproductive coping. Significant reduction was noticed in their proneness to heart disease, depression, inadequate mental mastery, and perceived ill health. There was significant improvement in their family group support, and in their expressiveness, achievement, orientation, active-recreational and organizational characteristics.  相似文献   
13.
14.
INTRODUCTION Since the phenomenon of piezoelectricity in natural crystals was discovered in 1880, it has been applied in many fields, such as smart structure, sensing devices and active control, because of its special properties. Combining electrical behavior with mechanical deformation is the special property which attracted great interest of researchers. Many models have been developed for studying piezoelec- tric effects. Dunn and Wienecke (1996) used Green’s functions for transverse…  相似文献   
15.
Although the U.S. population is becoming increasingly diverse, the race of individuals entering the counseling profession remains predominantly White (S. P. Pack‐Brown, 1999). The authors define and explore the connection between White privilege and oppression and encourage the use of racial identity models to address these constructs with counselor trainees in supervision.  相似文献   
16.
The authors evaluated an unfolding case‐based approach to a practicum in counseling course infusing crisis, trauma, and disaster preparation for changes in students’ crisis self‐efficacy across a semester. The course, informed by constructivist‐developmental pedagogy and centered on the unfolding case, resulted in significant increases in students’ crisis self‐efficacy.  相似文献   
17.
Whereas research in MicroSystems Technology (MST) has grown rapidly over the last twenty years, the education of engineers at postgraduate level is still in its infancy. The number of dedicated MST research institutions, companies and university laboratories worldwide has grown at a dramatic rate and all require trained individuals who can be immediately operational in the workplace. With the possible exceptions of Germany and Switzerland, the authors of this article believe that the training requirements for such scientists, engineers and technicians have not been satisfactorily addressed as yet. Realising the need for adequate training in MST, the British funding agency for research in science and engineering, the EPSRC (Engineering and Physical Sciences Research Council) awarded a substantial grant to Heriot-Watt University in order to set up a Masters Training Package (MTP). The context of this grant, the syllabus developed for this Master of Science as well as its implementation are presented in this article. Advantages and drawbacks of block-based delivery of the course are presented from a pedagogical point of view for the different categories of students (full-time students, part-time students and company delegates).  相似文献   
18.
19.
Both cross sectional and longitudinal studies of change with age in mental ability and cross sectional studies of change with age in cognitive performance indicate that the ability to learn generally does not decline in adulthood but continues at a stable and responsive level well into the later years. This conclusion is not only supported by psychological research but also confirmed by the rapidly growing numbers of older persons who are returning to and succeeding in the pursuit of educational activities. If and when decline does occur, it is usually modest, often reversible, rarely extreme, and rarely if ever great enough to preclude the possibility of learning that may be highly meaningful to the older learner.Howard Y. McClusky is the charter President of the Adult Education Association of the U.S.A. and a Fellow of the American Psychological Association. He is currently active as an Adjunct Professor in the Department of Adult and Continuing Education and Faculty Associate in the Institute of Gerontology at the University of Michigan, Ann Arbor, Michigan 48109.  相似文献   
20.
INTRODUCTION It is well-known from the genetic code structure that there exists a connection between codons and physical and chemical amino acid properties (Lewin, 1983). Codon properties in turn are defined by physical properties of the nucleotides from which they are compounded (Ratner, 1985; 2000). The most important properties of nucleotides as complex three-dimensional molecules are their dipole moment, heat of formation and energy of the most stable con- formation (Schneider and Be…  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