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   133篇
  免费   4篇
教育   46篇
科学研究   37篇
各国文化   1篇
体育   19篇
文化理论   16篇
信息传播   18篇
  2023年   1篇
  2022年   2篇
  2021年   5篇
  2020年   3篇
  2019年   14篇
  2018年   9篇
  2017年   10篇
  2016年   9篇
  2015年   6篇
  2014年   6篇
  2013年   17篇
  2012年   8篇
  2011年   10篇
  2010年   4篇
  2009年   6篇
  2008年   5篇
  2007年   2篇
  2006年   2篇
  2004年   1篇
  2003年   3篇
  2002年   2篇
  1999年   2篇
  1998年   1篇
  1996年   1篇
  1994年   1篇
  1991年   1篇
  1990年   1篇
  1988年   1篇
  1982年   2篇
  1981年   1篇
  1980年   1篇
排序方式: 共有137条查询结果,搜索用时 0 毫秒
11.
The Large Hadron Collider at CERN, the European Organisation for Nuclear Research, is the world’s highest-energy particle accelerator. Its construction (1995–2008) required frontier technologies and close collaboration between CERN scientists and contracting firms. The literature on “Big Science” projects suggests that this collaboration generated economic spillovers, particularly through technological learning. CERN granted us access to its procurement database, including suppliers of LHC from 35 countries for orders over 10,000 Swiss Francs. We gathered balance-sheet data for more than 350 of these companies from 1991 to 2014, which include the years before and after that of the first order received. The study assesses, in quantitative terms, whether becoming a CERN supplier induced greater R&D effort and innovative capacity, thus enhancing productivity and profitability. The findings – which controlled for firms’ observable characteristics, macroeconomic conditions, and unobserved time, country, industry and firm-level fixed effects – indicate a statistically significant correlation between procurement events and company R&D, knowledge creation and economic performance. The correlation is chiefly driven by high-tech orders; for companies receiving non-high-tech orders, it is weaker, or even statistically not significant.  相似文献   
12.
Over the last years, there was an increasing interest in keeping suitable microclimatic conditions for the preservation of artefacts: the artefacts preservation requirements may diverge from those of the museums visitors, willing to enjoy the works of art in a situation of psycho-physical wellness. The HVAC designers and engineers will have then to cooperate closely with the curator, in order to define a compromise between conflicting environmental performance requirements. In particular at the stage of air-conditioning system design or retrofit, it is extremely important to carry out a series of preliminary analysis to evaluate and monitor the existing environmental conditions and to anticipatory simulate and predict the post-intervention conditions. To this aim, advanced fluid-dynamic investigation tools (Computational Fluid Dynamic [CFD] techniques) enable to deal with the specificity of such topics and provide a useful decision-making support.  相似文献   
13.
This study presents the results of an experiment which investigated analogical reasoning in knowledge acquisition in a natural school setting. The aims were to evaluate the efficiency of analogy in the conceptual restructuring of a science topic and compare the effects of analogy in different learning conditions. Two analogical topics of physics (water flow and heat flow) were studied by means of two experiments performed in the classroom with concrete objects. Eighty-four 5th graders, divided into three experimental conditions (given analogy, constructed analogy, no analogy), took part in the study. The quantitative analysis mainly confirms the hypothesis that analogy can be a productive way to trigger a process of knowledge restructuring while students learn a new topic. However, the effective use of the analogy was affected by the experimental condition: When the analogy was constructed by the learners themselves, instead of being presented and justified by the teacher, it acted indeed as a more powerful tool in understanding the new topic which required changing their initial conceptions. The qualitative analysis shows the children’s explanations of the heat flow phenomenon and different conceptual outcomes of the learning process. Finally, educational implications are considered.  相似文献   
14.
The aim of this study was to analyze the effects of resistance training (RT) performed with 1 or 3 sets per exercise on osteosarcopenic obesity (OSO) syndrome parameters in older women. Sixty-two older women (68.0 ± 4.3 years, 26.8 ± 4.4 kg/m2) participated in a 12-week RT program. Participants were randomly assigned into one of the three groups: two training groups that performed either 1 set (G1S, n = 21) or 3 sets (G3S, n = 20) 3 times weekly, or a control group (CG, n = 21). Body composition was assessed by dual X-ray absorptiometry, strength was evaluated by 1 repetition maximum testing. The G3S presented significantly higher strength changes than G1S. The changes for percentage of body fat were higher for G3S compared to G1S. There was no difference in skeletal muscle mass between G3S and G1S, however both training groups displayed greater increases in this outcome compared to CG. There was no effect for bone mineral density. The overall analysis indicated higher (< 0.05) positive changes for G3S than G1S (composed Z-score: G3S = 0.62 ± 0.40; G1S = 0.11 ± 0.48). The results suggest that a 12-week RT period is effective to improve the risk factors of OSO, and that 3 sets induce higher improvements than a single set.  相似文献   
15.
To provide a good understanding of many abstract concepts in the field of electricity above that of their students is often a major challenge for secondary school teachers. Many educational researchers promote conceptual learning as a teaching approach that can help teachers to achieve this goal. In this paper, we present Physlet-based materials for supporting conceptual learning about electricity. To conduct research into the effectiveness of these materials, we designed two different physics courses: one group of students, the experimental group, was taught using Physlet-based materials and the second group of students, the control group, was taught using expository instruction without using Physlets. After completion of the teaching, we assessed students’ thinking skills and analysed the materials with an independent t test, multiple regression analyses and one-way analysis of covariance. The test scores were significantly higher in the experimental group than in the control group (p < 0.05). The results of this study confirmed the effectiveness of conceptual learning about electricity with the help of Physlet-based materials.  相似文献   
16.
17.
18.
ABSTRACT

The main purpose of this study was to compare the effects of resistance training (RT) performed with different training volumes on phase angle (PhA), body water components, and muscle quality (MQ) in untrained older adult women. A second purpose was to assess the relationship between PhA and MQ. Sixty-two older adult women (68.6 ± 5.0 years, 65.2 ± 13.3 kg, 156.1 ± 6.2 cm) were randomly assigned into one of the three groups: two training groups performed either 1 set (G1S) or 3 sets (G3S), or a control group (CG). Body water components and PhA were estimated by bioelectrical impedance (BIA). MQ was determined by dividing skeletal muscle mass estimated by dual-energy absorptiometry (DXA) by total muscle strength from three exercises. After the intervention period, both training groups demonstrated improvements (< 0.05) when compared with CON for intracellular water, total body water, PhA, and MQ. These results suggest that RT can improve PhA, body water components, and MQ after 12 weeks of RT in untrained older women, regardless of training volume. Furthermore, changes in MQ were positively correlated with changes in PhA (r = 0.60, P < 0.01).  相似文献   
19.
The article presents a study on metalinguistic, cognitive and metacognitive abilities in university students. A sample of 353 students was recruited; 178 of which from scientific and 175 from humanistic Faculties, with gender balance (M = 178; F = 175) whose age range was between 20 and 25 years old. They were administered a metalinguistic ability test that assesses metalinguistic awareness at implicit and explicit levels (L and ML scores) and the Raven’s Standard Progressive Matrices 38 (SPM38). In addition to the usual nonverbal administration of the matrices, candidates were asked to justify in written form the reasons for the solution indicated in each item. Three scores were considered for the SPM38: the ordinary score based on the number of correct nonverbal solutions (O.S.), a 7-point scale for assessing the argumentation of the correct solutions (C.ARG.S.) and a 6-point scale for assessing the argumentation of the incorrect solutions (I.ARG.S.). Significant gender and curriculum effects were found, with males and scientific students dominating at the nonverbal level while females and humanistic students dominated in the argumentative abilities related to the matrices and in all the scores of the metalinguistic test. A number of significant correlations were found between all the metalinguistic, cognitive and metacognitive abilities considered, with a prominent role of the metalinguistic abilities at the explicit level (ML score) that show a clear argumentative structure very similar to the C.ARG.S. argumentations in the matrices test.  相似文献   
20.
The new Web generations are influencing the minds and changing the habits of software developers and end users. Users, librarians, and information services professionals can interact more efficiently, creating additional information and content and generating knowledge. This new scenario is also changing the behavior of information providers and users in health sciences libraries. This article reviews the new Web environments and tools that give librarians opportunities to tailor their services better, and gives some examples of the advantages and disadvantages for them and their users. Librarians need to adapt to the new mindset of users, linking new technologies, information, and people.  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