最优化特性和变化的流域初始状态对新安江模型参数的影响

本对流域状态和最优化特性是如何影响模型功能方面进行了研究．在假设流域诸多初始条件下，使用SCE-UA优化算法通过日模型率定新安江模型．结果发现流域的初始条件和最优化特性对待优化的参数有非常大的影响，并且使模型过程参数的响应程度变小．研究结果表明变化的初始条件对总产流的影响并不是太大．     

Psychometric properties and optimizing of the Bracken School Readiness Assessment

Educational Assessment, Evaluation and Accountability - The Bracken School Readiness Assessment (BSRA) has been used in large studies such as the Millennium Cohort Study (MCS). Important...     

Total Protein of Whole Saliva as a Biomarker of Anaerobic Threshold

Saliva provides a convenient and noninvasive matrix for assessing specific physiological parameters, including some biomarkers of exercise. We investigated whether the total protein concentration of whole saliva (TPWS) would reflect the anaerobic threshold during an incremental exercise test. After a warm-up period, 13 nonsmoking men performed a maximum incremental exercise on a cycle ergometer. Blood and stimulated saliva were collected during the test. The TPWS anaerobic threshold (PAT) was determined using the Dmax method. The PAT was correlated with the blood lactate anaerobic threshold (AT; r = .93, p < .05). No significant difference (p = .16) was observed between PAT and AT. Thus, TPWS provides a convenient and noninvasive matrix for determining the anaerobic threshold during incremental exercise tests.     

A spectral analysis of team dynamics and tactics in Brazilian football

Abstract

The purposes of this study were to characterise the total space covered and the distances between players within teams over ten Brazilian First Division Championship matches. Filmed recordings, combined with a tracking system, were used to obtain the trajectories of the players (n = 277), before and after half-time. The team surface area (the area of the convex hull formed by the positions of the players) and spread (the Frobenius norm of the distance-between-player matrix) were calculated as functions of time. A Fast Fourier Transform (FFT) was applied to each time series. The median frequency was then calculated. The results of the surface area time series median frequencies for the first half (0.63 ± 0.10 cycles · min^?1) were significantly greater (P < 0.01) than the second-half values (0.47 ± 0.14 cycles · min^?1). Similarly, the spread variable median frequencies for the first half (0.60 ± 0.14 cycles · min^?1) were significantly greater (P < 0.01) than the second-half values (0.46 ± 0.16 cycles · min^?1). The median frequencies allowed the characterisation of the time series oscillations that represent the speed at which players distribute and then compact their team formation during a match. This analysis can provide insights that allow coaches to better control the team organisation on the pitch.     

Approaches and Methodologies for a Course on History and Epistemology of Physics: Analyzing the Experience of a Brazilian University

This paper is an analysis of inserting history and philosophy of science (HPS) in a physics undergraduate program at a Brazilian university. It is an examination of the approaches and methodologies adopted by professors of a History and Epistemology course. The course aims to have an explicit approach to HPS. The results suggest a concern of the Physics Institute regarding inserting these questions into physics teacher training programs. The study also uncovered that the professors who taught the subject had different visions of HPS.     

The geometric curvature of the spine during the sirshasana,the yoga’s headstand

This study analysed the behaviour of the geometric curvature of the spine during sirshasana. The position of dorsal retroreflective markers was computed via stereophotogrammetric analysis in six males and five females (29.4 ± 8.8 years, 63.0 ± 11.4 kg, 1.66 ± 0.08 m [average ± standard deviation]). The spinal points were projected onto the sagittal and frontal planes of the trunk, a polynomial was fitted to the data and the two-dimensional geometric curvature was quantified. The inferior lumbar lordosis decreased compared to the orthostatic position and gait, which may favour the posterior protrusion of the lumbar spinal nucleus pulposus in people with posterior herniation. The lateral deviation at the middle of the thoracic spine increases during sirshasana, which may reflect increased difficulties for postural control and spinal loads. It could be useful for promoting positive spinal structural and functional chronic adaptations for healthy participants, if the yoga programme is carefully planned and the spinal alignment is carefully monitored during a headstand. However, it may aggravate some spinal diseases, especially scoliosis.     

大坝与坝基稳定性分析研究

大坝与坝基的稳定一直是工程师密切关注的一个安全问题. 论文提出2种分析重力坝和坝基稳定的方法: 一种是基于刚体极限平衡原理的直接分析方法, 它将坝体和岩基作为不变形的刚体, 利用该方法可直接计算出可能滑动面的安全因数; 另一种是基于弹塑性理论的间接分析方法, 它采用非线性有限元方法分析大坝和坝基的应力和变形. 根据收敛和突变准则来确定稳定安全度.结果表明:工程建筑物的破坏不仅仅是由于施加荷载的原因,同时也与组成材料的性质有关.     

Newton and Colour: the Complex Interplay of Theory and Experiment

The general aim of this paper is to elucidate some aspects of Newton's theory of light and colours, specially as presented in his first optical paper of 1672. This study analyzes Newton's main experiments intended to show that light is a mixture of rays with different refrangibilities. Although this theory is nowadays accepted and taught without discussion it is not as simple as it seems and many questions may arise in a critical study. Newton's theory of light and colour can be used as an example of the great care that must be taken when History of Science is applied to science teaching. An inadequate use of History of Science in education may convey to the students a wrong conception of scientific method and a mythical idea of science.     

Virtual Teaching Dispositions in an Open Distance Learning Environment: Origins,Measurement and Impact

An understanding of the key characteristics and implicit competencies underlying online teaching is essential to distance education institutions that embark on the assertive use of technology in their tuition development and delivery. The Virtual Teaching Dispositions Scale (VTDS) assists in investigating professional teaching dispositions associated with effective online instruction. It was initially validated among academic staff members at a residential university in the United States of America (USA). Strong support was found for the construct's cognitive, pedagogical and social presence that served as the conceptual foundation for developing the scale. The aim of this study was to validate the VTDS among academic staff members of an open distance learning (ODL) institution and to make suggestions for improving online teaching in this environment. This study highlights the need for interventions aimed at enhancing academic staff members’ experienced level of virtual/technological presence.