研究平抛运动实验方案的改进

目前数字化实验器材尚未普及,对于高中研究平抛运动实验,存在着各学校所用器材不统一,操作步骤繁琐,轨迹点定位效果不理想的缺点,基于这些原因,对教材中的方案二实验装置进行了改进.改进的装置由喷水装置、绘图板和直角坐标测量装置组成,改进后的装置具有操作简便,轨迹点坐标定位准确等特点.     

J-LD23型复摆实验装置的改进

针对J-LD23型复摆实验装置存在的不足,根据实验原理,采取了增加水平仪和量角器等诸多措施对原复摆实验装置进行了改进.改进后的实验装置操作简便,同时也提高了实验的准确性,减小了误差.     

阿贝成像原理与空间滤波实验教学

提出了一套新的阿贝成像原理和空间滤波实验教学方案,该方案能够较全面地实现数据测量、低通滤波、高通滤波和方向滤波.并采用改进的实验装置和测量方法进行实验,操作简单,数据准确,实验效果明显.     

平抛运动实验的改进

针对高中平抛运动实验中所用器材分散、描点效果不理想的缺点,对实验装置进行了改进. 改进的装置由J2135型碰撞实验器、绘图板和底板组成,并增加了活动托板和"L"型定位器等装置. 改进后的装置操作简便,运动轨迹描绘准确.     

“ 探究功与速度变化的关系”实验改进

讨论了人教版物理“ 探究功与速度变化的关系”的实验方案, 并针对方案的操作难点对实验装置提出 改进, 促进学生对“ 动能和动能定理”的理解     

“旋转的液体”实验再改进

针对教材中“旋转的液体”实验装置的不足,从实验器材的选取、实验装置的调整、实验操作安全环保等方面进行了改进.改进后的实验取材方便、操作安全、现象明显,也符合节能和环保的要求.     

液体表面张力系数实验装置的改进

对现有吊环法液体表面张力系数测量仪的水平调节装置、吊环升降装置存在的不足进行了改进,在原有仪器上增加了液体加热装置,以便对不同温度下的液体表面张力系数进行测量,实验说明新的实验装置更加科学合理.通过实验对比得出:新的实验装置操作方便、实验误差小、重复性好,有推广价值.     

双缝干涉测波长实验的改进

针对人教版教材中"双缝干涉测波长"的实验存在的不足,对传统装置进行了改进.改进的实验采用激光作为光源,实验现象可以直接在光屏上观察和测量,实验操作简单、误差小.利用该装置还可以探究相邻亮条纹的间距Δx与光波波长λ、双缝间距d、光源到屏的距离L之间的关系;该实验装置还可以演示泊松亮斑、单缝衍射、小孔衍射等实验,实验现象明显.     

弦线驻波实验装置改进

本文对典型弦线驻波实验中数据不够准确、驻波不稳定及实验可重复性差等现象进行了分析,明确其根本原因在于实验装置设计方案存在缺陷.提出了实验装置改进方案,一是引入拉力传感器取代狭缝刀口和悬挂重物,改变反射波的形成机理,并以弦线张力直接测量取代砝码重力间接计算;二是引入机械结构微调弦线长度以改变弦线张力和弦线上驻波波长.实验结果证明,改进后的实验装置能明显改善上述问题,该装置还可实施研究驻波规律的多个实验方案。     

基于DISLab平抛运动实验的改进

利用＂数字信息系统实验室＂（DISLab）对物体的平抛运动进行了实验研究,并针对实验装置中存在问题提出了改进方案,最后将改进后的实验装置与原实验装置的实验结果进行比较研究,结果表明改进后的实验装置明显地提高了测量精度。     

Exploring music

Radioactivity in the environment includes naturally occurring as well as man-made radionuclides. Meaningful estimates of their hazard to health require much care in obtaining representative environmental samples, appropriate sample preparation as well as proper calibration of the measuring system. Any harm from the low absorbed doses of ionizing radiation typically received from environmental radioactivity would only occur after a latent period of several years. Of these, cancer induction is considered to be the most important. Risk factors have been derived by a number of internationally recognized organizations, but there are difficulties in extrapolating from observations at a high dose and dose rate and for the lifetime of exposed populations. Examples of measurement of ²²²Ra, ⁹⁰Sr, ¹²⁵I, ²²⁶Ra, ¹²⁹I and ¹³⁷Cs in the environment are given. Harmful effects from environmental radioactivity have mostly been indistinguishable above natural incidence. For health purposes there may be little need for further increases in sensitivity of detection but there is a continuing need to ensure the greatest accuracy in measurements to avoid magnifying the inevitable uncertainties in estimating radiation hazards.     

Exploring PDA Configurations

This paper reviews the principle of the phase-Doppler particle sizer by means of examples of the effects of varying the various experimental parameters. The examples are computed by means of a comprehensive numerical model of a complete phase-Doppler system including many practical aspects such as aperture size, polarization filters and detector properties. First the phase-Doppler principle is explained as a logical development of an interferometric measurement of the phase of the light scattered from a particle. Then the standard phase-Doppler analyzer (PDA) is decribed followed by some newer or less known variations of the principle intended to measure, e.g., in the backscatter direction, to size very small particles or to determine the refractive index of a particle. Finally, the trajectory problem in PDA measurements is briefly discussed.     

Exploring invariant sets and invariant measures

We propose a method to explore invariant measures of dynamical systems. The method is based on numerical tools which directly compute invariant sets using a subdivision technique, and invariant measures by a discretization of the Frobenius-Perron operator. Appropriate visualization tools help to analyze the numerical results and to understand important aspects of the underlying dynamics. This will be illustrated for examples provided by the Lorenz system. (c) 1997 American Institute of Physics.     

Exploring hybrid-star matter at NICA and FAIR

We discuss constraints for the equation of state of hybrid-star matter which can be obtained from next-generation heavy-ion collisions at FAIR and NICA. Particular emphasis is on the planned NICA facility at JINR (Dubna) which will provide fixed target and collider experiments just in the relevant energy ranges.     

Exploring the Higgs portal

We study the Higgs portal from the Standard-Model to a hidden sector and examine which elements of the extended theory can be discovered and explored at the LHC. Our model includes two Higgs bosons covering parameter regions where the LHC will be sensitive to two, one or none of the particles at typical discovery luminosities for Standard Model Higgs production.     

学科探究与实验教学

讨论了什么是探究性学习，探究性学习和实验教学的关系，以及与物理学科结合的实例．     

Exploring the light-quark interaction

Two basic motivations for an upgraded JLab facility are the needs: to determine the essential nature of light-quark confinement and dynamical chiral symmetry breaking (DCSB); and to understand nucleon structure and spectroscopy in terms of QCD's elementary degrees of freedom. During the next ten years a programme of experiment and theory will be conducted that can address these questions. We present a Dyson-Schwinger equation perspective on this effort with numerous illustrations, amongst them: an interpretation of string-breaking; a symmetry-preserving truncation for mesons; the nucleon's strangeness σ-term; and the neutron's charge distribution.     

Exploring the light-quark interaction

Two basic motivations for an upgraded JLab facility are the needs： to determine the essential nature of light-quark confinement and dynamical chiral symmetry breaking （DCSB）; and to understand nucleon structure and spectroscopy in terms of QCD＇s elementary degrees of freedom. During the next ten years a programme of experiment and theory will be conducted that can address these questions. We present a Dyson- Schwinger equation perspective on this effort with numerous illustrations, amongst them： an interpretation of string~breaking; a symmetry-preserving truncation for mesons; the nucleon＇s strangeness σ-term; and the neutron＇s charge distribution.