对任意的2~(2m 1)-1个整数的分组     

曹德  蔡青  沈景清 《通化师范学院学报》1999,(2)

本文主要是利用鸽笼原理,推广了2~(2m 1)-1个任意整数的分组问题,从而得到了一个较好的结果。  相似文献   

智能计算研究进展与发展趋势   总被引：3，自引：0，他引：3       下载免费PDF全文

黄德双 《中国科学院院刊》2006,21(1):46-52

智能计算技术是一门涉及物理学、数学、生理学、心理学、神经科学、计算机科学和智能技术等的交叉学科,近年来发展迅猛。本文简要介绍了智能计算的学科背景、原理和特点,评述了国际的发展现状和趋势。  相似文献   

Relating students' reasoning to the history of science: The case of chemical equilibrium   总被引：1，自引：0，他引：1  

Jan H. Van Driel  Wobbe De Vos  Nico Verloop 《Research in Science Education》1998,28(2):187-198

In this study, the reasoning of students, who are introduced to the concept of chemical equilibrium, was related to the historical development of this concept. In the first stage of the study, remarkable similarities were observed between students' reasoning on the issue of incomplete chemical conversions and the reasoning of 19th-century scientists, especially when molecular notions were included. In the next stage of the study, some authentic problems and questions, that were essential in the historical development of chemical equilibrium, were presented to students. It appeared that they recognised the significance of these problems and questions. Moreover, most students were eager to find explanations. Students, reasoning in molecular terms, would sometimes explain these problems in terms similar to historical explanations. Other students, however, suggested explanations in non-molecular terms, which, although chemically valid, did not appear to have historical antecedents. It was concluded that the study of authentic historical sources may inspire the design of effective teaching activities.  相似文献   

以医学科研人员为中心实施感动服务的探讨     

刘燕清  陈德 《科技管理研究》2005,25(7):53-54

医疗机构的改革必然对医院科研管理人员提出更高的要求,本文提出以医学科研人员为中心、以感动服务为基点的全新服务意识和服务方式。医院科研管理人员必须树立“甘为他人作嫁衣”的无私奉献精神,转变服务观念,提供感动服务,并通过不断学习,提高自身素质,在服务中不断创新,更好地为医院科研服务。  相似文献   

Archives in motion: Concrete steps towards the digital disclosure of audiovisual content     

Laurence Hauttekeete  Tom Evens  Katrien De Moor  Dimitri Schuurman  Erik Mannens  Rik Van de Walle 《Journal of Cultural Heritage》2011,12(4):459

Various authors have stressed the need for an adequate archiving and preservation policy of audiovisual material, given its cultural, historical, juridical, social and economic value. In view of the sustainable preservation of audiovisual material, the opening up of the archive is seen as a real challenge. Various aspects, such as requirements concerning formats, metadata standards and legal implications, need to be taken into account. Furthermore, different types of users should be able to consult the archive in a user-friendly way, a factor which should not be neglected. This article studies and discusses the current situation in Flanders regarding the digitisation and disclosure of the Flemish audiovisual cultural heritage, comprising the audiovisual material in the archives of different Flemish institutions, including broadcasters, (post-) production companies, government institutions and cultural organizations. Based on 45 qualitative interviews, a SWOT analysis is created to assess the strengths, weaknesses, opportunities and threats concerning the digitisation and disclosure of the audiovisual archive. Moreover, this environmental analysis includes some recommendations concerning the future preservation of this audiovisual cultural heritage.  相似文献   

Book reviews     

Leonardo Fuentealba Hernandez  Lotte Schenk-Danzinger  M. J. Langeveld  Per Kirstein  Richard D'Aeth  R. E. Hennion  Fritz Bohnsack  Hans Thomae  Oskar Anweiler  L. J. Pongratz  G. De Landsheere  Hans Möckelmann 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1961,7(3):358-376

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Validity and feasibility of an obstacle course to assess fundamental movement skills in a pre-school setting     

Brooke Klingberg  J. J. A. A. M. Hoeboer  Natasha Schranz  LM Barnett  Sanne I. De Vries 《Journal of sports sciences》2019,37(13):1534-1542

Failure to master age-appropriate fundamental movement skills (FMS) at a young age can limit motor skill competence affecting health. Assessments often have issues with feasibility and implementation in a field setting. As such, the purpose of this study was to investigate the validity and feasibility of the Athletic Skills Track (AST), in a pre-school setting. For the validation study sixty-five 3–6 year old children (25 boys and 40 girls) from five pre-schools across Adelaide, Australia participated. Correlations and linear regression analysis (adjusted for age and gender) were used to investigate the association between the time to complete the AST and the raw score of the Test of Gross Motor Development 2 (TGMD-2). For the feasibility study pre-school staff completed a semi-structured interview regarding the feasibility of the AST. The AST took less than a minute per child and the TGMD-2 around 20 minutes for two children. There was a strong negative correlation (r = ?0.63, p < 0.01) between the AST scores and the TGMD-2 scores. All five staff reported strengths of the AST to be its short administration time, setup and appropriateness. These results suggest that the AST could be a feasible and valid method of FMS assessment in Australian pre-schools.  相似文献   

Running speed-induced changes in foot contact pattern influence impact loading rate     

Bastiaan Breine  Philippe Malcolm  Samuel Galle  Pieter Fiers  Edward C. Frederick  Dirk De Clercq 《European Journal of Sport Science》2019,19(6):774-783

Purpose. We aimed to determine the effect of speed-induced changes in foot contact patterns on the vertical instantaneous loading rate (VILR). We hypothesized that transition runners, i.e. runners that shift towards a mid- (MF) or forefoot contact pattern (FF) when running speed increases, show smaller increases in VILR than non-transition runners, i.e. runners that remain with a rearfoot contact pattern (RF).

Methods. Fifty-two male and female runners ran overground at 3.2, 4.1, 5.1 and 6.2?m?s^?1. Ground reaction forces, lower limb sagittal plane knee and ankle kinematics and plantar pressures were recorded. Multi-level linear regression models were used to assess differences between transition and non-transition runners.

Results. Non-transition runners experienced larger speed-induced increases in VILR (48.6?±?2.6?BW?s^?1 per m?s^?1) than transition runners (–1.4?±?7.6?BW?s^?1 per m?s^?1). Transition runners showed higher VILRs and a more flat foot touch down at the same pre-transition speed than non-transition runners.

Conclusion. When running speed increases, some runners transition towards more anterior foot contact patterns. This reduces or even eliminates the speed-induced increase in VILR. This result is especially the case for those RF runners who already have relatively high VILRs and flat foot positioning at slower running speeds.  相似文献   

Thermo-formation process of plastic shells for winter sport boots for improved comfort     

Martino Colonna  Nicola Pazi  Matteo Moncalero  Claudio Gioia  Federico De Bon  Davide Giovanelli  Elisabetta Farella 《Sports Engineering》2017,20(4):275-282

We have performed a study on the thermo-formation process of plastic shells of boots for winter sports. The aim of the work has been to determine how the process parameters can improve the ergonomic and thermal comfort for athletes and winter sports participants. We have found that the initial deformation and memory effect are strongly influenced by the type of thermoplastic material used, heating time and cooling procedure. We have also found that the ovens currently used for this process are not correctly designed to obtain an efficient heat transfer and, therefore, a heating time of at least 12 min is necessary to achieve an average deformation of more than 2 mm. The measure of the boot flexural stiffness has shown that there are no changes in the load–deflection behavior after the thermo-formation process of a ski boot made of thermoplastic polyurethane. We have also found that the thermo-formation process decreases the pressure on skier’s feet of more than five times and, therefore, improves the comfort of the skier.  相似文献   

Effect of sex and fatigue on muscle stiffness and musculoarticular stiffness of the knee joint in a young active population     

Dan Wang  Giuseppe De Vito  Massimiliano Ditroilo  Eamonn Delahunt 《Journal of sports sciences》2017,35(16):1582-1591

The purpose of this study was to investigate the influence of sex and fatigue on knee extensor peak torque (PT), muscle stiffness (MS) of the vastus lateralis (VL) and knee joint musculoarticular stiffness (MAS) in young adults. Twenty-two male and 22 female recreational athletes participated. Males were characterised by higher relaxed [pre-: males 364.43 (52.00) N · m^–1, females 270.27 (37.25) N · m^–1; post-: males 446.75 (83.27) N · m^–1, females 307.39 (38.58) N · m^–1] and contracted [pre-: males 495.07 (71.04) N · m^–1, females 332.34 (85.42) N · m^–1; post-: males 546.37 (90.74) N · m^–1, females 349.21 (85.55) N · m^–1] MS of the VL, and knee joint MAS [pre-: males 1450.11 (507.98) N · m^–1, females 1027.99 (227.33) N · m^–1; post-: males 1345.81 (404.90) N · m^–1, females 952.78 (192.38) N · m^–1] than females pre- and post-fatigue. A similar finding was observed in pre-fatigue normalised knee extensor PT [pre-: males 2.77 (0.42) N · m kg^–1, females 2.41 (0.40) N · m kg^–1, post-: males 2.53 (0.54) N · m kg^–1, females 2.26 (0.44) N · m kg^–1]. After the fatigue protocol, normalised knee extensor PT and knee joint MAS decreased, whilst relaxed and contracted MS of the VL increased in both sexes. These observed differences may contribute to the higher risk of knee injury in females and following the onset of fatigue.  相似文献