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   118篇
  免费   3篇
  国内免费   1篇
教育   69篇
科学研究   10篇
体育   31篇
文化理论   3篇
信息传播   9篇
  2023年   1篇
  2022年   3篇
  2021年   2篇
  2020年   4篇
  2019年   8篇
  2018年   8篇
  2017年   11篇
  2016年   6篇
  2015年   1篇
  2014年   4篇
  2013年   17篇
  2012年   9篇
  2011年   6篇
  2009年   5篇
  2008年   4篇
  2007年   4篇
  2006年   1篇
  2005年   3篇
  2003年   5篇
  2002年   3篇
  2001年   1篇
  1999年   1篇
  1998年   1篇
  1997年   1篇
  1996年   2篇
  1993年   1篇
  1992年   1篇
  1991年   1篇
  1990年   1篇
  1989年   1篇
  1988年   1篇
  1979年   1篇
  1976年   1篇
  1974年   2篇
  1973年   1篇
排序方式: 共有122条查询结果,搜索用时 31 毫秒
61.
62.
Public procurement can be a major source of innovation. The potential benefits of public procurement might be fully exploited through the acquisition not only of appliances which are already available in the market, but also of new appliances which are tailored to the specific needs of the local community and might be exported as well to the international markets. In this way, public procurement might allow to improve the services delivered to the local community and to increase the technological competitiveness of the local industrial and research system. In this context, regional foresight might help identify both long-term societal needs and the patterns of evolution of emerging technologies that can match these needs. The purpose of this paper is to illustrate, trough the recent experience of the regional government of Lombardy, the role of foresight for enhancing public procurement and innovation policy at the regional level.  相似文献   
63.
Abstract

Kinematic analysis of swimming is of interest to improve swimming performances. Although the video recordings of underwater swimmers are commonly used, the available methodologies are rarely precise enough to adequately estimate the three dimensional (3D) joint kinematics. This is mainly due to difficulties in obtaining the required kinematic parameters (anatomical landmarks, joint centres and reference frames) in the swimming environment. In this paper we propose a procedure to investigate the right upper limb’s 3D kinematics during front crawl swimming in terms of all elbow and shoulder degrees of freedom (three rotations of the shoulder, two of the elbow). The method is based upon the Calibrated Anatomical Systems Technique (CAST), a technique widely used in clinics, which allows estimation of anatomical landmarks of interest even when they are not directly visible. An automatic tracking technique was adopted. The intra-operator repeatability of the manual tracking was also assessed. The root mean squared difference of three anatomical landmarks, processed five times, is always lower than 8 mm. The mean of the root mean squared difference between trajectories obtained with the different methodologies was found to be lower than 20 mm. Results showed that complete 3D kinematics of at least twice as many frames than without CAST can be reconstructed faster and more precisely.  相似文献   
64.
To address the inability of current ranking systems to support subtopic retrieval, two main post-processing techniques of search results have been investigated: clustering and diversification. In this paper we present a comparative study of their performance, using a set of complementary evaluation measures that can be applied to both partitions and ranked lists, and two specialized test collections focusing on broad and ambiguous queries, respectively. The main finding of our experiments is that diversification of top hits is more useful for quick coverage of distinct subtopics whereas clustering is better for full retrieval of single subtopics, with a better balance in performance achieved through generating multiple subsets of diverse search results. We also found that there is little scope for improvement over the search engine baseline unless we are interested in strict full-subtopic retrieval, and that search results clustering methods do not perform well on queries with low divergence subtopics, mainly due to the difficulty of generating discriminative cluster labels.  相似文献   
65.
This paper investigates the determinants of the propensity of firms to export new products, and focuses on the role of new imported inputs. Importing offers access to new technologies and better combination of inputs that can lead to new or improved products for the export markets. Based on a sample of more than 14,000 Swedish manufacturing firms over the period 2001–2012, we show that importing new inputs is a key determinant of firms’ propensity to add new products to their export portfolio, even after controlling for multinationality, patenting activity, productivity and a number of other firm characteristics. This is mainly due to the import of new intermediate inputs and it is stronger for smaller firms.  相似文献   
66.
This paper studies the effects of skilled migration on innovation –proxied by patent citations- in European industries between 1994 and 2005, using the French and the UK Labour Force Surveys and the German Microcensus. Highly-educated migrants have a positive effect on innovation, but the effect differs across industries. It is stronger in industries with low levels of overeducation, high levels of FDIs and openness to trade and, finally, in industries with higher ethnic diversity. The aggregate effect of the skilled immigrant is about one third the one of the skilled natives. We tackle the endogeneity of migrants with a set of external and internal instruments.  相似文献   
67.
The purpose of this investigation was twofold: (a) to explore and describe the relationships between different facets of motivation, involvement, and commitment to running, and (b) to test whether recreational coached runners differ from non-coached runners in their motivation, involvement, and commitment to running. Drawing on the psychological continuum model (PCM), a model was proposed to test relationships among motives, attitudinal and behavioral involvement, and commitment to running as a leisure activity. Results showed that two (enjoyment and health) out of five motives were significant indicators of attitudinal involvement. Attitudinal involvement was a significant predictor of behavioral involvement, which in turn was a significant predictor of commitment. Coached runners differed from non-coached runners in all tested variables. The structural relationships among the variables varied based on the tested group. Implications for theory and practice are presented.  相似文献   
68.
This is a longitudinal study of first year medical students that investigates the relationship between the pattern change of the learning preferences and academic performance. Using the visual, auditory, reading‐writing, and kinesthetic inventory at the beginning of the first and second year for the same class, it was found that within the first year, 36% of the class remained unimodal (single) modality learners (SS), 14% changed from unimodal to multimodality learners (SM), 27% changed from multimodality to unimodal modality learners (MS) and 21% remained as multimodality learners (MM). Among the academic performance through subsequent didactic blocks from Clinical Anatomy, Cell and Subcellular Processes to Medical Neuroscience during first year, the SM group made more significant improvement compared to the SS group. Semi‐structured interview results from the SM group showed that students made this transition between the Clinical Anatomy course and the middle of the Medical Neuroscience course, in an effort to improve their performance. This study suggests that the transition from unimodal to multimodality learning among academically struggling students improved their academic performance in the first year of medical school. Therefore, this may be considered as part of academic advising tools for struggling students to improve their academic performances. Anat Sci Educ 11: 488–495. © 2017 American Association of Anatomists.  相似文献   
69.
Research on students’ conceptions of learning is a growing and complex area of interest in the field of psychology of education. Even though much of the investigation addressed to explore conceptions of learning at the university level, still less research has considered how naïve (i.e. ‘learning as reduction of deficit knowledge through individual effort’) and sophisticated (i.e. ‘learning as opportunity and self-efficacy’) conceptions of learning are related to personal and contextual factors. This research investigated how gender, academic area, and level of study influence university students’ conceptions of learning. Three hundred forty-six university students participated in the study. They were either from humanities (240) or technical-scientific (106) areas of study and they were attending either a Bachelor (140) or Master’s degree (206) course. Conceptions of learning were explored using a self-report instrument (Learning Conceptions Questionnaire; LCQ). A MANOVA revealed that females show conceptions of learning more related to social and motivational aspects of learning with a greater personal involvement, compared with males. No typical pattern of conceptions of learning was found for humanities students or for technical-scientific students. Increasing with the level of study, students showed both naïve and sophisticated conceptions of learning increased, since both ‘learning as reduction of deficit knowledge through individual effort’ and ‘learning as opportunities and self-efficacy’ were more likely. Implications of these results and future lines of research will be discussed.  相似文献   
70.
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