物理课堂实施"探究-建构"教学模式探索

随着社会政治、经济的迅猛发展，我国的素质教育重心转移到培养学生的创新能力和实践能力．新一轮课程改革指出要建立新的教学方式，并将科学探究作为课程改革的突破口，以知识与技能、过程与方法、情感态度与价值观构建课程目标，培养全面发展的人．这对课堂教学提出了更高的要求，传统的课堂教学已不适应，必须加以改革．在中学物理教学中“探究一建构”型物理课堂教学是一种与新课程相协调的教学模式，它本着“突出学生主体地位，探究物理知识的形成过程，实现知识的意义建构，培养学生科学精神”的宗旨，对传统的课堂教学提出了挑战．     

"单摆的研究"研究性教学探究

随着全国新一轮中小学课程改革的全面推进，教育界关于研究性教学开展的如火如荼．研究性教学是基础教育课堂教学改革的重要内容，作为一种教学方式，其特点是教师不把现成的结论告诉学生，而是启发学生自己发现问题，按照科学的方法进行探究，从而获取知识或应用知识解决问题．如何从教学实际出发，以学生的发展为本，加强课堂教学的研究，本文以“单摆的研究”课堂教学为例，对研究性教学做了一些探究，与各位同行商榷．     

从主动建构学习观探讨物理教学的演变趋势

传统物理教学是以教师讲授为中心,教师代表知识的权威,也是传递者,此教学方式虽可让学生“听”到大量知识,但学生却不见得能了解所听到的,更谈不上可在真实的生活中加以应用．近年来盛行“建构主义”的思潮,正掀起一波物理教学与教材的改革浪潮．物理教学的演变趋势如下：减少套公式做机械式的反复计算,重视概念的了解;减少教师唱独角戏式的解说分量,重视课堂的互动与引导学生讨论思考,以提升学生主动建构;教学内容走向生活实例的情境化,物理概念的学习须靠生活经验加以强化;加强合作式的学习,学习个体与其外界应建起有意义的关系．依据上述的演变趋势,本文提出一套供非主修理工学生的物理通识课程,课程强调科学探究的精神,采用学生亲自动手做实验的上课方式,教材内容着重生活化的题材,此课程经施教后获得了学生高度的正面反应．     

小议探究式物理实验教学中的"猜想"

1探究式物理教学中“得出结论”环节存在的问题 现行的物理教学比较注重采用科学探究的教学方式．通过探究式教学，学生可以积极参与其中，领悟科学探究的思想，培养他们进行科学探究所需要的能力，从而更好地学习和运用知识．通常，科学探究有七个要素：提出问题、猜想与假设、制定计划与设计实验、进行实验与收集数据、分析与论证、评估、交流与合作．但是，从现行的“探究式教学”中，     

物理教学中引导学生进行科学探究的策略分析

实施新课改后, “探究式教学”成为老师们常用的一种上课模式.因为,中物理新课程倡导“以探究为特色,以学生的发展为本”的新理念,让学生“主动地参与学习,建构他们的物理学知识”,探究式教学是一种用科学探究方式去获取知识、应用知识、解决问题的教学方式,它很好的体现了“培养学生物理科学素养”这一全新要求.     

浅谈我校的"学生自主实验"

我校（初中）在这两年开展了“学生自主实验”．这是因为新的物理课程，要求教师尽快地从“为考试而教”转变为“为创造而教”，不再是“教参～教材一学生”的教学程序和模式，而要变成“学生一活动一教材”的物理教学新模式，从而进入到教育创新的广阔天地．基于这种教学理念，我校“学生自主实验”区别于课堂上的教师演示实验与学生实验，是学生在已有知识基础上自主质疑，应用学校实验室提供的仪器及化学药品（仪器及药品目录挂在实验室外墙上，学生可以随时查阅），自拟探究课题，或选择实验室提供的课题（课题也在实验室外墙上），     

关于探究式教学中"分析与论证"要素的若干解读

探究式教学中的“分析与论证”是指学习者在探究过程中，在获得实证的基础上，将探究结果与自己原有的知识联系起来，运用分析、综合、归纳、演绎等科学研究方法，找到事件的因果关系或其他解释，形成超越学生原有知识和当前观察结果的新的理解．“分析与论证”是构成探究式学习过程中的诸多要素之一．那么，分析论证在科学探究中有什么意义？高中物理新课标对“分析论证”要素提出了什么要求？分析论证要素与探究要素之间的关系如何？教学中如何引导学生进行分析论证？本文试围绕这些问题，谈谈对分析论证要素的若干认识．     

将《新课标》的精神引入高中习题课教学之中——高一"动能定理"习题课改革尝试

《普通高中物理课程标准（实验）》（下称《新课标》）对课程目标提出知识与技能、过程与方法、情感态度与价值观的三维要求．《新课标》在课程实施上提出：“应促进学生自主学习，让学生积极参与，乐于探究，勇于实验，勤于思考．通过多样化的教学方式，帮助学生学习物理知识与技能，培养其科学探究能力，使其逐步形成科学态度与科学精神．”《新课标》突出了培养学生的创新能力．     

"密度"探究教学设计案例分析

密度是初中物理教学重点内容之一，也是课程标准中要求的七个重点知识之一．学好本节知识是进一步学习力学知识的基础，所以“密度”这节课是本章的重点课．“密度”是在学习了“质量”之后而引入的一个新的物理量，它在全章中起到承上启下的作用，既是在质量的基础上对物质世界的进一步探索，也是掌握测定物质密度的方法和解决有关密度的实际问题的基础，并为更深入学习液体压强、浮力等知识做铺垫．由于本节课的教学目标要求通过实验探究找出同种物质的质量和体积成正比的关系，因此本案例采用探究教学策略．     

物理教学实施探究式学习的三个原则

新课程标准明确指出：“高中物理课程应促进学生自主学习，让学生积极参与、乐于探究、勇于实验、勤于思考．通过多样化的教学方式，帮助学生学习物理知识与技能，培养其科学探究能力，使其逐步形成科学态度与科学精神．”因此，物理教学中探究式学习应着力于学生学习方式的改善，让学生体验科学探究过程，了解科学研究方法，增强创新意识和实践能力；激励学生在教学过程中主动学习和探究精神，调动学生学习的主动性、积极性，促进其个性全面健康地发展和情感、态度、价值观的自我体现．但目前的教学中，仍存在一定的认识误区和实践中的错误倾向．笔者根据对探究式学习的理解和实践认为物理教学的本质是科学的学习，而科学探究是科学学习的核心．可以说，中学物理教学的最终目标应是在学习物理知识的过程中，初步培养学生建立科学探究的意识和能力．为了达到这个目标，应在平时教学中引导学生进行探究式学习．在教学中实施探究式学习还应注意三个原则．     

NOx formation and flame velocity profiles of iso- and n-isomers of butane and butanol

NO formation and flame propagation are studied in premixed flames of iso- and n-isomers of butane and butanol through experimental measurements and direct simulation of experimental profiles. The stabilized flame is realized through the impingement of a premixed combustible jet from a contraction nozzle against a temperature-controlled plate. The velocity field is obtained by means of Particle Image Velocimetry (PIV) and nitric oxide concentration profiles are measured using Planar Laser Induced Fluorescence (PLIF), calibrated using known NO seeding levels. It is found that NO formation in n- and iso-isomers is comparable under the conditions considered, except for rich butanol mixtures, whereby NO formation is higher for iso-butanol. Generally, less NO is formed in butanol flames than in the butane flames. The experiment is simulated by a 1D chemically reacting stagnation flow model, using literature models of C1–C4 hydrocarbons [Wang et al., 2010] and butanol combustion chemistry [Sarathy et al., 2009, 2012]. NO prediction is tested using two of these mechanisms with a previously-published NO_x submechanism added into the butane and butanol models. While a good level of agreement is observed in the velocity field prediction under lean and stoichiometric conditions, discrepancies exist under rich conditions. Greater discrepancies are observed in NO prediction, except for the C1–C4 mechanism which shows good agreement with the experiment under lean and stoichiometric conditions. The current study provides data for further development of mechanisms with NO_x prediction capabilities for the fuels considered here.     

Quantum and surface properties of free films and nanoshells of molecular and atomic thicknesses

An original technology and the properties of new thin film nanoobjects, free films and shells of molecular and atomic thicknesses, are presented. Special attention is paid to shells of monoatomic or monomoleculer thickness with unique surface properties that have not been found in bulk materials.     

Experimental and Theoretical Study of the Electronic States and Spectra of TeH and TeLi

Gas-phase emission spectra of the hitherto unknown free radical TeLi have been measured in the NIR range with a Fourier-transform spectrometer. The emissions were observed from a fast flow system in which tellurium vapor in argon carrier gas was passed through a microwave discharge and mixed with lithium vapor in an observation tube. Two systems of blue-degraded bands were measured at high spectral resolution in the ranges 8000-9000 and 5700-6700 cm(-1) and vibrational and rotational analyses were performed. In order to aid in the analysis of the experimental data, a series of relativistic configuration interaction calculations has been carried out to obtain potential curves for the low-lying states of TeLi and the isovalent TeH and also electric dipole transition moments connecting them. As in the TeH system, the ground state of TeLi is found to be X(2)Pi(i), but with a remarkably smaller spin-orbit splitting. The TeLi calculations indicate a strongly bound A(2)Sigma(+) state, while in TeH the analogous state is computed to lie significantly higher at approximately 32 000 cm(-1), and it is strongly predissociated. Based on the theoretical analysis, the observed TeLi band systems are assigned to the transitions A(2)Sigma(+)(A1/2)-->X(1)(2)Pi(3/2)(X(1)3/2) and A(2)Sigma(+)(A1/2)-->X(2)(2)Pi(1/2)(X(2)1/2). Analysis of the spectra has yielded the molecular constants (in cm(-1)) X(1)(2)Pi(3/2):omega(e)=457.49(3), omega(e)x(e)=2.482(9), B(0)=0.408908(8); X(2)(2)Pi(1/2): T(e)=2353.44(3), omega(e)=456.28(4), omega(e)x(e)=2.635(8), B(0)=0.414954(8), p(0)=1.00637(4); A(2)Sigma(+): T(e)=8574.64(2), omega(e)=437.81(3), omega(e)x(e)=2.581(8), B(0)=0.423903(8), p(0)=-0.19915(2), where the numbers in parentheses are the standard deviations of the parameters. Comparison of the isovalent TeLi and TeH systems emphasizes that the difference in bonding character (ionic in TeLi vs covalent in TeH) is responsible for qualitative differences in the electronic spectra of these two molecules. Copyright 2001 Academic Press.     

Topological dislocation-type defects and mechanisms of plasticity and failure of nanostructured and amorphous materials

Possible mechanisms of plastic deformation and failure of nanostructured and cluster amorphous materials have been considered. It is shown that the most probable carriers of plastic deformation in these materials are macrodislocations—linear topological defects of the regular nanocrystallite packing in the nanostructure or cluster packing in amorphous materials. Continuum models are proposed to describe the processes of plastic deformation and failure of nanostructured and cluster amorphous materials. Original Russian Text ? L.S. Vasil’ev, S.F. Lomaeva, 2009, published in Izvestiya Rossiiskoi Akademii Nauk. Seriya Fizicheskaya, 2009, Vol. 73, No. 1, pp. 128–131.     

Geometry and Elasticity of Strips and Flowers

We solve several problems that involve imposing metrics on surfaces. The problem of a strip with a linear metric gradient is formulated in terms of a Lagrangian similar to those used for spin systems. We are able to show that the low energy state of long strips is a twisted helical state like a telephone cord. We then extend the techniques used in this solution to two–dimensional sheets with more general metrics. We find evolution equations and show that when they are not singular, a surface is determined by knowledge of its metric, and the shape of the surface along one line. Finally, we provide numerical evidence by minimizing a suitable energy functional that once these evolution equations become singular, either the surface is not differentiable, or else the metric deviates from the target metric.     

MCNP-FISPACT耦合燃耗计算程序开发与测试

反应堆堆芯的燃耗计算关系到堆芯的燃料管理,并直接影响堆芯的经济性评估,因此如何快速且准确地对堆芯进行燃耗计算一直是反应堆物理设计的研究重点之一。随着反应堆的发展,其几何结构和物理特性日渐复杂,现有的一维、二维耦合燃耗程序因其在几何处理上的限制,难以满足先进反应堆精细设计分析的要求。为对复杂反应堆堆芯的燃耗情况进行计算,结合粒子输运程序MCNP 处理复杂几何和燃耗程序FISPACT处理核素全面的特点,开发了接口程序耦合MCNP 和FISPACT来进行燃耗计算,并对耦合程序进行了计算验证。采用了IAEA 基准校核例题和CFETR中国聚变工程实验堆例题进行程序验证,经计算得出的有效倍增因子随燃耗的变化曲线和TBR等数据与标准例题的结果符合良好,其误差在可接受范围内。     

Some problems of analysis and optimization of plates and shells

The classical optimization problems of plates and shells to satisfy a priori given geometry and dynamical characteristics are considered. Orthotropic plates and shells with variable thickness and low transverse stiffness are analyzed. First, some useful theorems and their proofs are given. Then the finite approximation of the problem related to optimization of free vibrations of shells with transverse deformation and rotary inertia is discussed. The varational iteration (MVI) and Bubnov-Galerkin (MB) methods are applied, and their convergence and suitability for application to plates and shells analysis are discussed and numerically evaluated.