圆滚线运动的等时性

当一圆轮沿一直线作纯滚动时,轮缘上任一点在空间的运动轨迹就是圆滚线,或称旋轮线.在经典力学中这是一条非常有趣又非常有用的曲线.借助于它来讨论圆轮沿直线作纯滚动时轮缘上任一点的速度和加速度就不需要考虑两个运动的迭加.有趣的是质点沿圆滚线运动具有等时性,惠更斯并据此做成了理想摆.所以圆滚线又称为最落每项线或摆线.     

圆滚线摆的等时性研究

介绍一种具有真正等时性的Cycloid摆－圆滚线摆，通过计算机测量进行了验证。     

10 MeV质子等时性回旋加速器的设计研究

给出10MeV质子等时性回旋加速器的等时性磁场设计,中心区的设计以及加速后最终的束流品质,该加速器可作为正电子断层扫描装置的配套设备,用于生产中短寿命放射性同位素等.它沿半径方向只用一套线圈励磁,等时性磁场的建立完全由磁极形状决定.中心区的设计满足了轨道中心化的要求,并给出较大的横向和纵向接受度,以获得足够的束流强度. 经过172圈加速后,最终的束流品质满足要求.     

储存环HIAF-SRing等时性模式的非线性磁场影响研究

高精度环形谱仪SRing（Spectrometer Ring）是强流重离子加速器装置（HIAF）的重要组成部分,其等时性模式为远离β稳定线的短寿命原子核质量和寿命的精确测量提供国际领先的科研条件。为了扩大短寿命原子核质量测量精度和范围,SRing等时性模式设计了两种光学:γ_t=1.43和1.67。质量分辨是衡量等时性储存环的最重要参数。二极磁铁的高阶场以及磁铁的边缘场能强烈地引起束流光学高阶畸变,对质量分辨产生影响,因此需要高极磁铁对其进行校正。介绍了SRing等时性模式的线性计算,对非线性磁场的影响进行了详细研究。应用六极磁铁和八极磁铁对非线性场和发射度的影响进行了校正后,离子的循环时间标准偏差σ（T）/T达到3.5×10-7,质量分辨△m/m达到1×106。The isochronous mode of the Spectrometer Ring at the High Intensity heavy-ion Accelerator Facility (HIAF) project in China offers the capacity of measuring the mass and half-life of short-lived nuclides. The transition energy settings of the SRing are 1.43 and 1.67, which have been calculated in the same injection scheme. The resolution of mass or revolution time is the most important parameter of the isochronous mode design of a storage ring. The nonlinear magnetic field errors, including high-order magnet field of dipole, fringe field of magnets, have strongly effect to the resolution of revolution time. High-order corrections are required to improve the resolution of revolution time and mass. In this paper, the SRing linear isochronous optical were shown. The influence of nonlinear magnetic field errors on the revolution time resolving power were investigated. With 3 sextupole families and 1 octupole family corrections, the relative variation of revolution time reaches 4.6×10-7 with the momentum spread of ±0.2%. The relation of the relative standard revolution time deviation σ(T)/T and revolution turns was researched. With corrections of high-order isochronous condition and emittance influence by 3 sextupole families and 1 octupole family, one can reach a resolution of up to σ(T)/T=3.5×10-7, which corresponds to the mass resolution of △m/m=1×106.     

质点沿可自由移动的光滑凹槽的运动分析

分析了质点在可自由移动的凹槽上运动的运动平面与凹槽的交线是一般曲线的情况,给出了质点在静止参考系中运动的轨迹方程和严格等时振动的条件,求出了质点沿几种常见曲线运动的周期.     

圆外(内)旋轮线演示仪的制作及研究

制做了圆外(内)旋轮线演示仪,并对其产生的图案进行了分析. 圆外(内)旋轮线演示仪能在较大规模的场合清晰、醒目地演示圆外(内)旋轮线,并能容易地在各个图案间切换.     

HIAF-SRing的等时性模式光学设计

高精度环形谱仪SRing作为HIAF装置的核心之一,是获取高品质放射性次级束,并将束流用于加速器技术研究、原子物理及核物理实验的关键设备。SRing有三种运行模式:等时性模式、正常模式与内靶模式。等时性模式下,SRing运行在特殊线性光学设置下,可以精确测量寿命低至几十微秒的原子核的质量。介绍SRing等时性模式的线性光学及高阶项校正的设计方案。在使用程序GICOSY进行等时性高阶项校正数值计算后,将得到的光学传输矩阵输入到程序MOCADI进行粒子跟踪模拟。以γ_t=1.43的等时性模式为例,SRing的动量接收度为±0.20%,粒子跟踪结果显示,在仅满足一阶等时性条件时SRing的质量分辨能力R=1.6×104。在保证动量接收度不变的前提下,考虑了等时性高阶项校正后SRing的质量分辨能力提高到R=1.2×106,达到设计要求。The Spectrometer Ring, as the most important experiment terminal of the High Intensity heavy-ion Accelerator Facility (HIAF) project, is a key device to obtain high-quality radioactive ion beams (RIBs) for atomic physics, nuclear physics experiments and accelerator technology researches. Three operation modes including the isochronous mode, the normal mode and the internal target mode, have been designed for the SRing. In the isochronous mode, the SRing operates under a special ion optics and could be used for precision mass measurement of short-lived nuclei with half-life shorter than several tens of microseconds. This study aims to design the ion optics for the isochronous mode and improve the mass resolving power of the SRing with higher-order ion-optical correction scheme for isochronism while preserve a large momentum acceptance of SRing. The ion optics and the higher-order correction for the isochronous mode are calculated with the code MAD-X and GICOSY respectively. Three ion optics with γ_t=1.43, 1.67, 1.83 settings have been calculated. The code MCOADI which utilizes the matrixes generated by the code GICOSY is used for particles tracking to verify the correction results. For the ion-optical setting of γ_t=1.43 with a momentum acceptance of ±0.20%, the mass resolving power of the SRing could be improved from R=1.6×104 to R=1.2×106, after isochronous higher-order corrections.     

球在可自由移动的球形空腔内作纯滚动的运动分析

对在光滑水平面上可自由移动的球形空腔内作纯滚动的球的运动进行分析,给出球心及其边缘上任意一点在静止参考系中的运动轨迹方程,并绘出它们相应的轨迹,求出球在球形空腔内平衡位置附近作小振动的周期,并和球在可自由移动的球形空腔内作纯滑动的情况作了比较.     

行星的视运动与圆外旋轮线

用简化模型（行得在同一平面内绕太阳作匀速圆周运动）分析了行星相对于地球的运动（视运动）。给出了视运动的运动方程，证明了行星视运动的轨迹与圆外旋轮线，讨论了行星的顺向运动与逆向运动，给出了关于水星、金星、火星、土星、木星的数值结果。     

用于太赫兹光源的准等时性储存环的设计

介绍了一种获得准等时性储存环的方案,即调节Lattice参数,在色散段引入负色散函数从而降低线性滑相因子,获得短束团。根据此方案设计了用于相干太赫兹光源的准等时性储存环,结果给出了线形光学函数曲线以及粒子的动力学孔径,表明了通过调节四极铁参数可以达到降低束团长度获得准等时性储存环的目的。还设计了用于准等时性储存环弯铁处的真空室的3维模型,并对其类腔体部分的本征模进行了计算,得到特性阻抗与品质因数的比值在10-3量级以下,表明类腔体部分对束流的影响很小。

     

曲线运动中的相对静止

讨论物体在曲线运动中的相对静止，提出转动参照系中几种角速度之间的关系式。     

曲线运动中速度方向的演示实验

高中教材中没有演示曲线运动速度方向的演示实验,只举了两个生活实例.一个是观察在砂轮上磨刀具的情形,当刀具与快速旋转的砂轮接触时,就会看到一束束火星从接触点沿着砂轮的切线方向飞出.     

高考中两种曲线运动的综合问题的分析

圆周运动和（类）平抛运动是高中物理中两种典型的曲线运动;前者为变速曲线运动,后者为匀变速曲线运动．在考题中往往把两种运动综合在一起形成较为复杂运动问题,以下举例分析,以便共同探讨．     

自制曲线运动的条件演示仪

“曲线运动的条件”是高一物理“曲线运动”一节中的教学重点和难点，过去教师往往先直接告诉学生结论，然后用简单的实验去验证．学生被动接受这一知识，印象不深，参与率不高．为了激发学生的科学探究热情，培养学生主动参与意识、动手和观察能力，提高实验效果，设计了物体做曲线运动的条件演示仪，在实际教学中取得了很好的效果．     

例谈曲线运动中分析力与运动关系的重要性

力与运动的关系是高考大纲中要求学生重点掌握的主干知识,几乎贯穿了中学物理力学和电磁学部分的所有章节,地位十分重要;学生在学习牛顿运动定律这一章时也都会比较重视．但不少学生由于并没有真正理解,所以在学习其他章节时往往就会忽略对力与运动关系的分析,造成理解不透,掌握不牢;在学习曲线运动、万有引力两章就会很明显地出现上述问题．     

借用转动惯量的概念解决质点曲线运动问题

通过对质点圆周运动与刚体定轴转动的对比研究,将刚体的转动惯量的概念引入到质点曲线运动的研究中,以简化质点曲线运动的分析和处理过程．     

Curvilinear deflagration of energetic materials

The effects of material interface curvature on deflagration of a homogeneous solid energetic material (EM) is studied in a limit when the radius of curvature is much larger than the deflagration front thickness. Under the assumption of quasi-steady burning, a method of matched asymptotics is employed do derive first-order curvature corrections to the mass flux across the gas–solid interface as well as to the interface temperature. As an illustration, a problem of quasi-steady spherical particle deflagration is solved numerically and the simulation results are used to verify those obtained through asymptotic analysis. An algorithm for a fully-coupled unsteady solver suitable for EM deflagration simulation is presented. Numerical solution of the unsteady spherical particle deflagration is used to show that the assumption of quasi-steady deflagration is valid.     

The Radiation from Curvilinear Electron Beams in Periodical Magnetic Fields

In this paper we have tried to use the concept of working a relativistic laser on free electrons (FEL) that is based on the effect of a magnetic-braking radiation of charge particles moving along curve trajectories. In a region of small particle velocities (much less than the light speed), this concept could be realized with the radiation efficiency being substantially by a considerable deformation of the electron beam trajectory.     

利用分解和微元法求复场中曲线运动的最远距离

运动的合成与分解是研究复杂运动的重要方法.在研究比较复杂的运动时,常常采用分解的方法,将运动看作是两个或几个比较简单的运动组成的,使问题容易解决.在应用分解的方法时要注意"运动的独立性原理".这是物体运动的一个重要特性,即一个物体同时参与几种运动,各分运动都可看作是独立进行的,它们互不影响.