"黑箱"教学中激发学生兴趣的尝试

物理教学中有不少“黑箱”习题,可用于培养发散思维、推理、灵活运用知识的能力．一些学生对“黑箱”问题感到困惑、害怕．怎样在“黑箱”教学中激发学生学习兴趣呢？以下是笔者一节“黑箱”习题课的教学片段．     

高中物理发散性思维教学探议

实施素质教育是为了培养学生的创新能力和实践能力,而发散性思维是培养创新思维的突破口,在教学中,我们应注意培养学生的发散性思维,提高他们的创新能力.文章通过分析发散性思维的重要性,提出了高中物理发散思维教学培养的策略和教学设计及实施,以期为全面培养学生发散性思维作出贡献.     

深度学习,提升物理习题课的有效性

习题课教学在如今的高中物理教学中占了三分之一左右的时间,但目前习题课效率普遍低下,很多学生沦为缺乏思维的做题机器.教学失败的原因何在?笔者认为主要还是教师缺乏理论的指导,尚未形成统一的理念.新授课教学,现在的主流是建构主义,那么习题课教学呢?受理科学习中"深度学习"能力的性别差异启发,笔者想到如果在习题课教学中如果教师能有效引导各类学生深度学习,是不是既可以达到巩固复习的教学目的,又可以充分发展深度学习的能力,从而充分挖掘学生自身潜力,最终化教师的辛苦为学生自身研究的辛苦.     

一题多解博采众长

1习题课教学现状分析 在高考指挥棒的作用下,我们高中的习题课变了味,变成了难题、偏题的展览会,变成了标准化答案的制造厂。我们应该意识到习题是物理问题的反映,问题应存在变化性和具体化,因此,我们在习题教学中追求答案的标准化是违背教学规律的,学生在如此的课堂教学中,接受的物理方法单一化,课堂气氛格外沉闷,直接抑制了学生的积极思维,     

基于思维型课堂基本原理的习题教学实践与思考——以屈膝下蹲过程中运动与相互作用关系为例

思维型课堂是培育物理学科核心素养的有效途径,习题教学是培育物理学科核心素养的重要载体.围绕思维活动这一核心将认知冲突、自主建构、自我监控和应用迁移有机融入到习题教学全过程.以屈膝下蹲过程中运动与相互作用关系为例,就习题课教学的目标叙写、凸显思维的教学流程、围绕思维互动的教学实践提出了实施建议.     

关于初中物理习题课的几点思考

习题课是初中物理教学课程中的重要环节之一.本文就初中物理课程中习题课中如何改善并创新教学手段,提高学生的学习兴趣提出了几点意见. 习题课是对已学知识的复习和巩固,同新授课相比,习题课的课程内容是对学生掌握的的知识的重复,学生在进行习题课程的时候相比新授课缺乏学习兴趣.     

物理教学中的创造性思维培养

探讨在物理教学中培养学生的创造性思维的问题 ,文章从三个方面进行讨论 :教师创新能力的充分开掘是培养创造性思维的前提 ;聚合、发散思维的有效激发是培养创造思维的基础 ;不断追求发散、聚合思维的有机结合是培养创造思维的关键。     

初中物理习题教学的几点策略

在物理课教学中,习题课是必不可少的一种课型,它贯穿于整个物理教学的始终．高效的习题教学可以起到深化、活化知识,巩固概念、规律;培养思维品质,提高应变能力;及时反馈信息,了解教学效果等作用．     

物理习题课的设计

通过习题课,可以使学生深化对物理知识的理解,领会物理学中特有的思维方式和基本方法论,培养分析问题,解决问题的能力.一堂好的物理习题课,需要用系统的科学方法去引导和训练学生. 习题课的设计应从如下三方面入手.1 制定明确的目标     

关于斜面体上物体所受的摩擦力问题的分——“问题导学”模式下的物理习题课教学

本文介绍了“问题导学”模式,并将该模式用于摩擦力习题课教学,笔者能够深切地感到,在物理教学中实施“问题导学”,学生处于积极的思维探索状态,使让学生在问题的分析和解决中得到知识、能力的建构。     

Evidence of Improvement in Various Impairments by Exercise Interventions in Patients with Knee Osteoarthritis: A Systematic Review and Meta-analysis of Randomized Clinical Trials

Purpose: To investigate improvement in various impairments by exercise interventions in patients with knee osteoarthritis (OA). Methods: We collected data on randomized controlled trials (RCTs) comparing the effects of exercise intervention with those of either nonintervention or psychoeducational intervention in patients with knee OA. Data on pain, stiffness, muscle strength, range of motion, flexibility, maximal oxygen uptake, and position sense were synthesized. The Grading of Recommendations Assessment, Development, and Evaluation system was used to determine the quality of the evidence. Results: Thirty-three RCTs involving 3,192 participants were identified. Meta-analysis provided highquality evidence that exercise intervention improves maximal oxygen uptake, and moderate-quality evidence that exercise intervention also improves pain, stiffness, knee extensor and flexor muscle strength, and position sense. The evidence that exercise intervention improves knee extension and flexion range of motion was deemed as undetermined-quality. Conclusion: In patients with knee OA, improvement in pain, stiffness, muscle strength, maximal oxygen uptake, and position sense with the use of exercise intervention can be expected. Although the quality of evidence of the effect of exercise intervention on range of motion was inconclusive, exercise intervention should be recommended for patients with knee OA to improve various impairments.     

Physiological aspects of a vocal exercise

The physiological aim of vocal exercises is mostly understood in intuitive terms only. This article presents an attempt to document the phonatory behavior induced by a vocal exercise. An elevated vertical position of the larynx is frequently associated with hyperfunctional phonatory habits, presumably because it induces an exaggerated vocal fold adduction. Using the multichannel electroglottograph (MEGG), the laryngeal position was determined in a group of subjects who performed a voice exercise that contained extremely prolonged versions of the consonant /b:/. This exercise is used by the coauthor (N.E.) as part of a standard vocal exercise program. Two of the seven subjects were dysphonic phonastenic patients, and the rest were normal trained or untrained persons. Different attempts to calibrate the MEGG confirmed a linear relationship with larynx height, provided electrode positioning was correct. The results showed that the exercise induced substantial vertical displacements of the larynx. Comparison with larynx height during voicing of other consonants showed that the /b/, in particular, tended to lower the larynx.     

The Relationship between Age and Change in Physical Functions after Exercise Intervention. Trainability of Japanese Community-Dwelling Older Elderly

The purposes of this study were to evaluate the relationship between age and changes in physical measurements after exercise intervention and to investigate the trainability of the older elderly. Two hundred seventy-six community-dwelling people aged 60 years and older practiced exercise intervention for 3 months. The measurements of physical functions were one-legged standing with eyes open and closed (OLS-O, OLS-C), functional reach test (FR), timed up and go test (TUG), maximum walking velocity, flexibility, and muscle strength. We evaluated the associations between age and the changes in these physical measurements. All measurements except for OLS-C significantly improved after intervention. The magnitude of the changes in hand-grip strength and FR after the intervention showed weak negative correlations with the subject''s age, but other measurements showed no correlations. In addition, there were no differences between younger elderly persons and older elderly persons with regard to changes in any measurements. These results suggested that the exercise intervention we applied could improve physical fitness in community-dwelling older people, regardless of their age. The older elderly were comparable to the younger elderly in trainability to improve physical fitness.     

Effect of Intradialytic Supine Ergometer Exercise on Hemodialysis Patients with Different Nutritional Status

Objective: It is important for hemodialysis patients to exercise while their nutritional status is being monitored. This study aimed to examine the difference in physical exercise function and the effect of exercise intervention in hemodialysis patients who were divided into two groups (high-nutrition and low-nutrition groups) based on the serum albumin levels. Method: A total of 26 outpatients (18 men and 8 women) undergoing hemodialysis (age: 66 ± 10 years) were included in this study. The patients'' body composition data (weight, body mass index, percentage of body fat, fat-free mass, and total body water) and physical functions (grip strength, knee extensor strength, open-eyed one-legged standing time, long sitting trunk anteflexion, and 6-minute walking distance [6MWD] test) were measured. The intervention was supine ergometer exercise during hemodialysis, and the patients exercised for 30 minutes during hemodialysis thrice a week. The intervention period was three months. Results: Compared to the high-nutrition group, the low-nutrition group showed a significant decrease in muscle strength. Furthermore, long sitting trunk anteflexion in the high-nutrition group and 6MWD in the low-nutrition group improved significantly after the intervention. Conclusion: The result of this study may indicate that 6MD can be improved by exercise during dialysis, regardless of nutritional status. It is said that low nutritional status has a negative impact on survival rate; thus, considering the impact on survival rate, it is hemodialysis patients with a low nutritional status that should be considered to introduce more active exercise during dialysis.     

充分发挥习题的作用培养学生独立解决问题的能力

课后习题不仅是对学生灵活应用所学知识的锻炼,也是培养学生独立分析问题、解决问题能力的有效渠道.本文通过对一道普通物理力学课程中常见习题可能得出的几种不同结果及其原因的分析,对如何通过习题帮助学生提高独立解决问题的能力进行了探讨.     

Formation of a weakly diverging caustic beam in an underwater sound channel open to the bottom

The paper studies the patterns manifesting themselves in the formation and propagation of caustic and weakly diverging beams using the geometric acoustic approximation and mode theory applied to the simplest model of an underwater sound channel open to the bottom in the form of the bilinear dependence of the square of the refractive index on depth. It is established that when a vertical array emitting a tonal sound signal is located at a certain critical depth, the multimode caustic beam which forms near the reference ray horizontally departing from its center and which predominates in intensity is simultaneously the most weakly diverging beam. It is shown that the reference ray of such a weakly diverging caustic beam corresponds to the smoothest minimum for the dependence of the length of the ray cycle on their angle of departure from the center of the array and to the depth level of revolution at the critical depth characteristic of the given oceanic waveguide.     

Effects of back extensor strengthening exercises on postural alignment,physical function and performance,self-efficacy,and quality of life in Japanese community-dwelling older adults: A controlled clinical trial

Objective: To examine the changes in postural alignment and kyphosis-correlated factors after 6 months of back extensor strengthening exercise in a group of community-dwelling older adults aged ≥65 years. Methods: We quasi-randomized 29 subjects into an intervention group treated with a back extensor strengthening program and a control group treated with a full-body exercise program. These groups completed 20-30 minutes of exercise directed by a physical therapist one or more times per week and were instructed to exercise at home as well. The participants were assessed prior to and after the intervention using the following criteria: postural alignment of “usual” and “best” posture, physical function, physical performance, self-efficacy, and quality of life. The differences between two factors (group and period) were compared for each of the measurement variables. Results: Subjects who adequately completed the exercises were analyzed. A reduced knee flexion angle was noted in the “best” posture of both groups, as were improved physical function and performance with the exception of one-leg standing time. Verifying the effect size in the post-hoc analysis, the body parts that showed changes to postural alignment after the intervention differed between groups. Conclusions: Back extensor strengthening exercises improved physical function and performance, but did not improve spinal alignment. The changes due to these interventions were not significantly different from changes observed in the full-body exercise group. However, post-hoc analysis revealed that the effect size of posture change was different, possible indicating that the two groups experienced different changes in the postural alignment.     

Skin temperature evaluation by infrared thermography: Comparison of two image analysis methods during the nonsteady state induced by physical exercise

The most common method to derive a temperature value from a thermal image in humans is the calculation of the average of the temperature values of all the pixels confined within a demarcated boundary defined region of interest (ROI). Such summary measure of skin temperature is denoted as Troi in this study. Recently, an alternative method for the derivation of skin temperature from the thermal image has been developed. Such novel method (denoted as Tmax) is based on an automated (software-driven) selection of the warmest pixels within the ROI. Troi and Tmax have been compared under basal, steady-state conditions, resulting very well correlated and characterized by a bias of approximately 1 °C (Tmax > Troi).Aim of this study was to investigate the relationship between Tmax and Troi under the nonsteady-state conditions induced by physical exercise. Thermal images of quadriceps of 13 subjects performing a squat exercise were recorded for 120 s before (basal steady state) and for 480 s after the initiation of the exercise (nonsteady state). The thermal images were then analysed to extract Troi and Tmax. Troi and Tmax changed almost in parallel during the nonstead -state. At a closer inspection, it was found that during the nonsteady state the bias between the two methods slightly increased (from 0.7 to 1.1 °C) and the degree of association between them slightly decreased (from Pearson’s r = 0.96 to 0.83). Troi and Tmax had different relationships with the skin temperature histogram. Whereas Tmax was the mean, which could be interpreted as the centre of gravity of the histogram, Tmax was related with the extreme upper tail of the histogram. During the nonsteady state, the histogram increased its spread and became slightly more asymmetric. As a result, Troi deviated a little from the 50th percentile, while Tmax remained constantly higher than the 95th percentile. Despite their differences, Troi and Tmax showed a substantial agreement in assessing the changes in skin temperature following physical exercise. Further studies are needed to clarify the relationship existing among Tmax, Troi and cutaneous blood flow during physical exercise.     

Chirped and curved grating coupler focusing both outgoing beam and guided wave

A new type of a grating coupler is proposed which couples out diverging or converging guided wave into stigmatically focused outgoing beam or vice versa. Theoretical analysis based on the holographic approach is given in some details. Experiments on photoresist gratings support the theory and show their prospective application as beam forming couplers for guided-wave optics.     

在物理实验中变验证性实验为研究性实验

以塞曼效应为例,通过思考题的形式引导学生根据实验目的,对实验内容进行思考分析,设计出实验方案,并将实验方案在实验室中得以实施和优化,将传统的验证性实验变成了研究性实验。通过实验使同学们牢固地掌握了所学内容,对相关仪器设备的性能和使用有了更深入的理解,有效地培养了他们的创新意识和能力。