对体育锻炼中影响活动动机的心理因素的探究——一种多维动机观在体育锻炼中的应用

本文通过国内外的文献资料研究 ,并结合最新的心理研究成果 ,认为 :活动动机是影响人们参与体育活动的重要因素 ;影响体育锻炼的活动动机的心理因素是多方面和多层次的 ,其中主要有目标刺激方面的、行为方面的、认知方面的以及社会环境方面。而且 ,这些因素贯彻于活动的始终 ;有些心理因素不仅有利于促进体育锻炼 ,而且对人的健康成长都会产生积极影响。

新形势下的教育动机观研究

教师经常会面对一些没有学习兴趣、缺乏学习动机的学生,以及由于各种原因,虽有动机但又无法实行从而产生挫败感甚至出现放弃某学科、逃课、甚至退学念头的学生。如何排除学生的忧虑并激发他们的学习斗志,是广大教师直接面临的一个普遍问题。探讨如何使学生走出失败无奈阴影的策略是教师义不容辞的责任。

基于介观元胞自动机的城市区域人员疏散模拟方法

传统元胞自动机疏散模型中,空间多划分为微观层面的精细网格,难以对大范围的疏散场景进行模拟.基于此,本文结合行人流的运动特征,建立了应用于大尺度人员疏散场景的人员疏散介观元胞自动机模型.该模型以道路元胞划分替代平面网格元胞划分方式,并引入“源加载”元胞加载模拟场景内疏散人员,建立元胞间状态转移方程模拟疏散过程中的人员运动.应用该模型,对高校校园进行疏散子网划分,模拟应急疏散过程并规划疏散路径,既可以对场景内宏观疏散情况进行分析,又可以观测单个元胞的状态变化.基于模拟结果,能够发现实际疏散过程中可能存在的问题,提出相应的改进指引和意见.

组织绩效微观影响因素研究评述

绩效问题一直是管理学、组织行为学和人力资源管理研究的中心问题。文章从动机观—团队观—组织文化观这一主线分析组织绩效的微观影响因素,并从这一分析主线对组织绩效影响因素的研究成果进行了综述。在此基础上,本文对未来的研究方向进行了简要评述。

语文学习动机的概念与结构分析

学习动机的研究,已经从行为主义的动机观发展到社会文化的动机观。现阶段,有学者开辟了整合研究方向,提出了动机的自我调节论。基于此,认为语文学习动机是激发、维持学生学习行为,并使之朝向一定语文学习目标的一种内在过程或内部心理状态。进而,经过进一步分析可以看到,语文学习动机的基本结构,一般地包括认知内驱力(学习兴趣)、自我提高内驱力(自尊)、附属内驱力(奖励、批评)、自我效能感(成功)、意志(自觉、毅力)和成就归因(成绩)等六个维度。

课堂学习动机激发的思考

学生的学习主要是在课堂活动中进行的 ,因而有效地激发和维持学生的学习动机有助于学习结果的成功获取。根据认知主义的理论研究学习动机的激发应从任务设计、小组合作、主体转向、归因训练。

动机过程观、自我系统和二语动机策略研究

二语动机策略是二语学习动机和学习策略研究者共同关注的一个新研究领域。该类研究尚处于起步阶段,没有明确区分动机教学策略和动机学习策略,相关实证研究的理论框架和研究方法也比较单一。动机过程观是二语动机策略研究的基础,二语动机自我系统能为动机策略的机制给出更有力的理论解释。我们认为未来的二语动机策略研究有必要在自我系统理论框架下深入研究动机教学策略,关注动机学习策略及其培训,重视二语动机过程观对动机策略研究的影响。

未来取向研究回顾与展望

未来取向作为个体对于未来的思考和规划过程,近年来受到研究界日益广泛的关注并展开大量研究。笔者澄清了未来取向的含义,回顾了未来取向研究的沿革历程,梳理了近二十年在各研究领域取得的成果,并在此基础上提出当前该领域的未来发展趋向,即突破心理机制的瓶颈,拓展研究范围;扩展研究对象,进行纵向研究;强调社会文化的影响,进行跨文化的研究。

Evolution of microstructure of aluminum alloy hollow shaft in cross wedge rolling without mandrel

During the process of cross wedge rolling of aluminum alloy hollow shaft, the evolution of its microstructure has an important influence on the mechanical properties of the rolled piece. In order to obtain the microstructure evolution law of aluminum alloy hollow shaft in cross wedge rolling without mandrel, a finite element model is constructed through the finite element software Deform-3D. The influences of rolling temperature, sectional shrinkage,spreading angle and forming angle on the average grain size of rolled piece are studied by numerical simulation of microstructure evolution. The cellular automata method reveals the inherent relationship between the process parameters and the evolution of the microstructure, and provides a reference for optimizing the rolling process parameters of aluminum alloy hollow shafts and improving the forming quality. The results show that the average grain size of the rolled piece increases with the increase of the rolling temperature, decreases with the increase of the sectional shrinkage,and decreases first and then increases with the increase of the spreading angle, and changes little with the increase of the forming angle.

Effect of sodium carbonate addition on carbothermic reduction of ilmenite concentrate

The enhanced reduction mechanism and kinetics of different Na_(2)CO_(3) additions in the carbothermic reduction of ilmenite concentrate were investigated.The reduction process was carried out at different heating rates in a thermogravimetry facility,and the kinetics was studied using the Starink method.The results indicate that Na_(2)CO_(3) addition enhanced the reduction effect as well as reduced the initial temperature of the reaction and the activation energy by increasing reactant activity in reactant form;however,it deteriorated the late-stage kinetic conditions by generating a molten phase,thereby reducing the reaction rate in the late stages of reduction.The average apparent activation energies of ilmenite concentrate with 0%,3%,and 6%Na_(2)CO_(3) are 447,289,and 430 kJ/mol,respectively.The results from kinetics parameters confirm that Na_(2)CO_(3) addition accelerated the reduction kinetics;however,excessive addition worsened the reduction kinetics.

Pressure observer based adaptive robust trajectory tracking control of a parallel manipulator driven by pneumatic muscles

This paper presents a pressure observer based adaptive robust controller (POARC) for posture trajectory tracking of a parallel manipulator driven by three pneumatic muscles without pressure sensors. Due to model errors of the static forces and friction forces of pneumatic muscles, simplified average flow rate characteristics of valves, unknown disturbances of entire system, and unmeasured pressures, there exist rather severe parametric uncertainties, nonlinear uncertainties and dynamic uncertainties in modeling of the parallel manipulator. A nonlinear pressure observer is constructed to estimate unknown pressures on the basis of a single-input-single-output (SISO) decoupling model that is simplified from the actual multiple-input-multiple-output (MIMO) coupling model of the parallel manipulator. Then, an adaptive robust controller integrated with the pressure observer is developed to accomplish high precision posture trajectory tracking of the parallel manipulator. The experimental results indicate that the system with the proposed POARC not only achieves good control accuracy and smooth movement but also maintains robustness to disturbances.

The Modified Multiple Model Switching Tuning Control Application in AVC

In the complex mechanical vibration environment, the dominant frequency of the system varies remarkably and swiftly under various running conditions, which also characterizes uncertainty and time-variation. It is very impending and important to suppress or isolate the detrimental vibrations related to the above memtoned system with active vibration control (AVC) technology. This paper presented the improved linear quadratic gaussian (LQG) control scheme with a specified filter to realize broadband disturbance/noise attenuation and assure intensive suppression of vibration at the key vibration frequency, then applies and modifies the multiple model switching tuning (MMST) control method by disturbance observation to track the variation of dominant vibration component timely. The effectiveness and superiority of the presented control method were demonstrated by numerical simulation and AVC experiment on a flexible cantilever beam under sweeping excitation.

Passive control of Permanent Magnet Synchronous Motor chaotic system based on state observer

Passive system theory was applied to propose a new passive control method with nonlinear observer of the Permanent Magnet Synchronous Motor chaotic system. Through constructing a Lyapunov function, the subsystem of the Permanent Magnet Synchronous Motor chaotic system could be proved to be globally stable at the equilibrium point. Then a controller with smooth state feedback is designed so that the Permanent Magnet Synchronous Motor chaotic system can be equivalent to a passive system. To get the state variables of the controller, the nonlinear observer is also studied. It is found that the outputs of the nonlinear observer can approximate the state variables of the Permanent Magnet Synchronous Motor chaotic system if the system’s nonlinear function is a globally Lipschitz function. Simulation results showed that the equivalent passive system of Permanent Magnet Synchronous Motor chaotic system could be globally asymptotically stabilized by smooth state feedback in the observed parameter convergence condition area.

Topographic Indices and Yield Variability in a Rolling Landscape of Western Canada

Understanding the relationships between topographic indices and crop yield variability is important for soil manage- ment and crop production in rolling landscape. Two agricultural fields at Alvena and Hepburn, Saskatchewan, Canada were selected to examine how topographic indices were related to wheat yield under two topographic and weather conditions in the Canadian prairies. The landscapes of the two sites are classified as hummocky and the dominant soil type is an Aridic Ustoll. The relationships among yield, topography, soil, and weather were analyzed using wheat (Triticum aestivum L.) grain yield from Alvena in 2001 (dry year) and 2004 (wet year) and from Hepburn in 1998 (dry year). Topographic/soil indices included relative elevation, wetness index, upslope length, curvature, soil organic matter, and soil moisture storage before seeding. The results indicated that, in the dry years, the correlation coefficients between upslope length and grain yield were 0.79 for the typical rolling landscape (Alvena) in 2001 and 0.73 for shallow gentle rolling landscape (Hepburn) in 1998. In the wet year (2004), the relationships between yield and topographic/soil attributes were not as strong as in dry years. Therefore, upslope length was the best yield indicator for the two landscapes in dry years, whereas no topographic indices were highly correlated to crop yield in wet years. Those topographic indices seemed useful in identifying the yield variability and delineating the proper management zone.

Simulation of solidification microstructure of Fe-6.5%Si alloy using cellular automaton-finite element method

3D microstructures of Fe–6.5%Si(mass fraction) alloys prepared under different cooling conditions were simulated via finite element-cellular automaton(CAFE) method. The simulated results were compared to experimental results and found to be in accordance. Variations in the temperature field and solid-liquid region, which plays important roles in determining solidification structures, were also examined under various cooling conditions. The proposed model was utilized to determine the effects of Gaussian distribution parameters to find that the lower the mean undercooling, the higher the equiaxed crystal zone ratio; also, the larger the maximum nucleation density, the smaller the grain size. The influence of superheat on solidification structure and columnar to equiaxed transition(CET) in the cast ingot was also investigated to find that decrease in superheat from 52 K to 20 K causes the equiaxed crystal zone ratio to increase from 58.13% to 65.6%, the mean gain radius to decrease from 2.102 mm to 1.871 mm, and the CET to occur ahead of schedule. To this effect, low superheat casting is beneficial to obtain finer equiaxed gains and higher equiaxed dendrite zone ratio in Fe–6.5%Si alloy cast ingots.

Preliminary Study on Simulation of Global Seismic Activities with Global Strain Rate

The relationship between the strain rate field observed by GPS and global distribution of strong earthquakes is analyzed in this work. How do we recognize the characteristics of global seismic activities with space observation technology? A preliminary model of Cellular Automata that could simulate the global seismic activities both in time and space has been established based on the results of global strain rate field provided by the GSRM Program. The grid of the model is evenly divided,which is consistent with that of GSRM.The status of each cell is its strain state,and is adjusted according to the evolution rules.Maximum shear strain criterion is adopted in the evolution of the Cellular Automata. The threshold for cells in surface expansion is 80% of that for those in compression. The preliminary model could in general simulate the main characteristics of the distribution of the global seismic activities. It could exhibit in general the global distribution of weak and active tectonic activities. Although the preliminary Cellular Automata model needs to be improved in many aspects,the result suggests the possibility of modeling the general features of rather complicated global seismic activities based on the strain rates obtained by GPS and other observations.

Microscopic simulation of multi-lane traffic under dynamic tolling and information feedback

To investigate drivers' lane-changing behavior under different information feedback strategies,a microscopic traffic simulation based on the cellular automaton model was made on the typical freeway with a regular lane and a high-occupancy one. A new dynamic tolling scheme in terms of the real-time traffic condition on the high-occupancy lane was further designed to enhance the whole freeway's flow throughput. The results show that the mean velocity feedback strategy is generally more efficient than the travel time feedback strategy in correctly guiding drivers' lane choice behavior. Specifically,the toll level,lane-changing rate and freeway's throughput and congestion coefficient induced by the travel time feedback strategy oscillate with larger amplitude and longer period. In addition,the dynamic tolling scheme can make the high-occupancy lane less congested and maximize the freeway's throughput when the regular-lane inflow rate is larger than 0.45.

The Development and Influence of RCPS Instructions to Promote Students＇ Scientific Learning Motivation and Scientific Concept Learning

This research aims at developing RCPS （revised creative problem solving） teaching model, besides the authors designed the instructions of chemical reaction to promote eight grade students＇ scientific learning motivation and scientific concept learning. We adopted quasi-experiment study, the experimental group and controlled group all 28 students were chose, go on the parameter is analyzed together compared with textbook instructions, scale of scientific learning motivation and test of scientific conception learning were used for the two groups in prior test and post test, then they used statistical ANCOVA （analysis of covariance） to analyze the differences between the two teaching models. The result of this study finds that RCPS teaching model improved student＇s scientific learning motivation and learning scientific concept was superior to textbook instructions in controlled group, p = 0.001 （〈 0.01）, and all with high experimental treatment effects （〉 0.14）. The study also proposes that when RCPS teaching model was applied to scientific concept teaching, RCPS teaching model should be joined the conception introducing stage, and pay attention to students＇ scientific learning motivation.

Correlation between the senses of achievement and students＇ motivations at tertiary level in China

Educators and teachers generally agree that a major variable affecting students learning L2 or FL is motivation. This paper discusses the correlation between increasing the sense of achievement and sustaining students＇ motivations in a Chinese cultural setting, in which language learning should not be understood in terms of North American and Western cultural values. Considering EFL or ElL situations at a tertiary education level in China's Mainland, the author thinks that for university students, we should consider this issue in another way and concludes that, from the adults＇ psychological perspective, the sense of achievement, more than any other factor, plays the most important role in sustaining students＇ motivations, thus contributing greatly to the whole process of learning. Therefore, it should be viewed as a very useful and effective method to maintain students＇ motivations. Based on this idea, the author strongly suggests that while they are capitalizing on some effective methods or strategies to foster and maintain their students＇ motivations, EFL or ElL teachers should try every means and utilize any occasion to ensure that students can feel their achievement and see progress during the advanced level of learning, thus guaranteeing they will keep expending energy and effort in continued learning.

Coherence of a Chain of Chaotic Oscillators in a Nonlinear Gyrotropic Medium

We investigate the generalized Kuhn＇s model, namely, a chain of nonlinear chaotic oscillators describing a nonlinear gyrotropic medium. It is shown that despite the chaotic behavior of separate oscillators the chain preserves some coherency as a whole. The relation between the chain synchronization and the physical properties of a random mean field is established.