基于案例式教学法力学与理论力学 课程关联教学的研究

根据当代教育的发展和理论物理教学中存在的问题, 针对工程人才短缺和本科生培养质量问题, 提出 基于案例式教学法在力学与理论力学课程关联教学的思想, 介绍了案例式教学法的基本内涵, 同时探索了案例式 教学法在力学与理论力学课程关联教学的研究, 为培养国家急需人才提供了理论与实践的保障     

变质量问题的教学之浅见

本文阐明了变质量物体的运动这一内容在理论力学课的教学中的重要地位，提出了学生难以理解和容易混淆的几个问题，介绍了作者在教学实践中的几点做法。     

物理教学论文索引(1985年4～6月)

一、力学 1.论弹 性体 最小余 能原理的变分条件 黄文彬《力学与实践》1985年7卷2期41页. (以下年、卷、期、页顺序相同) 2.关于 著《弹性理论的接触问题》蔡海涛《力学与实践》1985.7.2.42. 3.关于我国材料力学书中 拉伸和压缩性能 章节的某些问题 老亮《力学与实践》.1985.7.2.46. 4.断裂力 学中Westergaard应力 函数 小议张恒等《力学与实践》1985.7.2.47. 5.应用虚位移原理时 解除某些 理想约束 的新方法 袁镒吾《力学与实践》1985.7.3.45 6.商榷虚位移等概念的讲授 方法 陈光寅《力学与实践》85.7.3.47. 7.虚功原理的一个推广形式 岳…     

异型碟形弹簧在武器工程支承结构设计中的应用

碟形弹簧具有轴向结构尺寸小、单位体积材料的变形能大及比较灵活的特陛曲线等特点，在工程上被广泛应用，但运用于武器工程支承结构设计还很鲜见。该碟簧在武器工程支承结构应用中主要起分担横向载荷的作用，与常规碟簧主要承担轴向载荷的特点是有很大差异的。加上其它综合因素的约束，设计面临很大困难。经过广泛技术调研，在理论分析基础上，提出异型碟簧支承形式。在该支承方式的力学计算涉及摩擦、滑动等非线性问题，计算难度较大情况下。通过试验方式对异型碟簧的力学f生能进行研究，得到相关试验数据。     

用质心运动定理解某些变质量物体运动的问题

在一般理论力学教材中，对变质量物体的运动问题，都采用变质量物体基本运动方程即宿舍尔斯基方程求解．本文提出了用质心运动定理求解该类问题中的一些典型例子，对理论力学教材中缺少质心运动定理某些应用题的情况是个补充．     

正则变换与勒让德变换

力学中变换理论占有很重要的地位，利用变换理论我们可以从力学的一种表述形式过渡到另一种表述形式，也可以在某种理论表述形式中寻找使问题易于求解的途径．本文将讨论分析力学中两种重要的变换：勒让德交换和正则变换，讨论它们所应满足的条件和相互影响，特别是将指出正则变换一般将破坏力学理论的拉格朗日表述和哈密顿表述之间的勒让德变换关系，从而澄清某些力学著作在处理这方面问题时的模糊之处．     

刚体惯量主轴与其上任一点的惯量主轴之关系

刚体的惯量主轴与惯量主轴上任一点的惯量主轴之间的关系问题，一般的力学、理论力学教科书大多没有提及，本文就此问题作了一些研究讨论．     

读《力学实验设计》一书

读《力学实验设计》一书杨述武（东北师范大学物理系）近来读了龚镇雄、张世良合著的《力学实验设计》一书，这是以普通物理实验的力学实验为目标的教学实验设计论著．该书在结论中详细讨论了指导物理教学实验设计的各方面问题之后，介绍了作者结合教学实践的１６个实验设...     

物理教学论文索引(1984年4～6月)

一、力学1.虚位移原理在运动学中的应用　高百争 《力学与实践》84年6卷2期49页 (以下年、卷、期、页顺序相同)2.确定平面问题应力函数的一种方法　刘惠文等 《力学与实践》84.6.2.513.关于屈曲杆最大挠度的近似计算式的讨论　裘子 秀《力学与实践》84.6.2.544.弹性力学平面问题的应力函数的选择　赵志文 《力学与实践》84.6.2.575.爱因斯坦等效原理与惯性力　胡楚雄 《力学与实践》84.6.3.486.关于刚体平面运动中动量矩原理的综合讨论　朱 晨 《力学与实践》84.6.3.497.关于虚位移原理新的陈述与证明　吴子明 《力学与实践》84.6.3.558.均…     

关于零质量粒子力学的教学

相对论力学的非真空零质量极限是与光量子的力学，是经典力学过渡到量子力学的桥梁。本研讨力学课程中讲授这种零质量粒子力学的必要性与可能性；在普通力学和理论力学两个层次上分别给出了教案；从科学和教学法两方面对现行的大学普物力学、理论力学、相对论和量子力学教学做了若干批评性述评。最后指出在力学课程中讲授零质量粒子力学的优点。     

Guided-Wave Two-Dimensional Acousto-Optic Scanner Using Proton-Exchanged Lithium Niobate Waveguide

Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs.     

Effect ofγ-radiation on the spectral luminescence characteristics of impure cadmium tungstate crystals

Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation (5.5·10⁴ Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure crystals is analyzed (preliminarily). Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997.     

Femtosecond Transform-Limited Pulse Generation by Compensating for the Linear Chirp of SPM Spectra in Dispersion Shifted Fibers

A simple technique of pulse compression, based on the linear chirp compensation of self-phase modulation (SPM) spectra in dispersion shifted fibers, is demonstrated. The optimization procedure is carried out, for a short span of a single-mode fiber, using a parabolic law, which describes the behavior of the squared output pulse width versus the pump peak power in the case of Gaussian pulses. The experimental results give a minimum pulse duration of 233 fs, which is in good agreement with the model. Shorter and coherent pulses, down to 90 fs, have been obtained by inserting an interference filter at the optical output.     

Sorting of bending magnets for the SSRF booster

The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper.     

Measurement of nonlinear coefficient of optical fiber based on small chirped soliton transmission

We measure the waveform and phase curves of short optical pulses before and after transmission over different lengths of fibers by use of the pulse analyzer with the frequency-resolved optical gating (FROG),and numerically simulate pulse evolution under the experimental conditions.The nonlinear coefficient of the fiber is given by comparing the experimental results with the numerical ones.Difference between the experiment and numerical simulation is analyzed.     

Resonance scattering of canonical elastic shells in absorbing fluid medium

Resonance scattering of elastic spherical shell and cylindrical shell while the surrounding fluid medium has absorption is studied. The normal mode solution derived using exact elastic theory and the separation of variables is still applicable. However, the scattering form function has to be modified for the absorbing medium, otherwise the unreasonable result would be obtained. The backscattering form function in the absorbing medium is redefined, and the form function of elastic spherical and cylindrical shell with vacuum or solid matter filled is calculated in various absorption conditions. The results show that the absorption of surrounding fluid leads to notable attenuation of the coincidence resonances in the mid-frequency, but it has a little influence on the low-frequency resonance scattering induced by the filler inside the shell.     

Single-beam self-referenced phase-sensitive surface plasmon resonance sensor with high detection resolution

A versatile and low-cost single-beam self-referenced phase-sensitive surface plasmon resonance(SPR)sensing system with ultra-high resolution performance is presented.The system exhibits a root-mean-square phase fluctuation of ±0.0028.over a period of 45 min.i.e.a resolution of±5.2×10-9 refractive index units.The enhanced performance has been achieved through the incorporation of three design elements:a true single-beam configuration enabling complete self-referencing so that only the phase change associated with SPR gets detected,a differential measurement scheme to eliminate spurious signals not related to the sensor response,and the elimination of retardation drifts by incorporating temperature stabilization in the liquid crystal phase modulato .Our design should bring the detection sensitivity of non-labeling SPR biosensing closer to that achievable by conventional fluorescence-based techniques.     

Influences of SiO2 protective layers and annealing on the laser-induced damage threshold of Ta2O5 films

Ta2O5 films are prepared on BK7 substrates with conventional electron beam evaporation deposition.The effects of SiO2 protective layers and annealing on the laser-induced damage threshold (LIDT) of the films are investigated.The results show that SiO2 protective layers exert little influence on the electric field intensity(EFI)distribution,microstructure and microdefect density but increase the absorption slightly.Annealing iS effective on decreasing the microdefect density and the absorption of the films.Both SiO2 protective layers and annealing are beneficial to the damage resistance of the films and the latter is more effective to improve the LIDT.Moreover,the maximal LIDT of Ta2O5 films is achieved by the combination of SiO2 protective layers and annealing.     

A stereo matching algorithm using multi-peak candidate matches and geometric constraints

Gray cross correlation matching technique is adopted to extract candidate matches with gray cross correla- tion coefficients less than some certain range of maximal correlation coefficient called multi-peak candidate matches. Multi-peak candidates are extracted corresponding to three closest feature points at first. The corresponding multi-peak candidate matches are used to construct the model polygon. Correspondence is determined based on the local geometric relations between the three feature points and the multi-peak candidates. The disparity test and the global consistency checkout are applied to eliminate the remaining ambiguous matches that are not removed by the local geometric relational test. Experimental results show that the proposed algorithm is feasible and accurate.