六孔物镜转换器的结构设计

为保证物镜转换器的对中精度在0．01mm以下,给物镜各放大倍率的互换带来更大的活动空间,设计了应用于高级显微镜上的六孔物镜转换器结构。转动板转轴结构借助了半运动学式圆柱形轴系理论,采用有限单元法对转动板和固定板的连接螺纹牙进行应力和应变分析,保证了转轴的回转角误差单边小于1′;通过减小物镜螺纹孔轴与转动板转轴之间的夹角及物镜在转换器上安装位置的分布圆半径,提高了对中精度。设计的六孔物镜转换器结构,为六孔物镜转换器的制造奠定了基础,对七孔物镜转换器的研发具有参考作用。     

Velocity profiles and discontinuities propagation in a pipe flow of suspension of motile microorganisms

Suspension of motile gravitactic unicellular algae flowing down in a vertical pipe concentrates near its axis in the form of a thin thread. Such a thread is unstable relative to the travelling nodule-like structures. We study the dynamics of nodules experimentally and describe them in terms of a hydrodynamic model.     

On the theory of radiation of an infinitely long charged current-carrying thread in a uniaxial transparent crystal

The problem relating to the synchrotron radiation of a charged current-carrying thread in a uniaxial transparent crystal is considered here using the Sitenko-Kolomensky method. The formulas for the intensity of the synchrotron radiation and the limiting values of the formulas giving the intensity of the Cerenkov radiation of a thread moving uniformly and rectilinearly parallel to the optical axis of a crystal have been derived.     

空间旋转多光轴平行性校准技术

空间旋转多光轴系统光轴平行性影响系统指向精度且校准难度高、耗时。基于空间旋转多光轴系统光轴校准原理,获得了校准理论模型;结合实验研究,建立了高精度光轴校准方案;以机械回转轴为基准,粗调准和精调准结合,以调整传感器安装面为粗调,借助双光楔实现光学量级的精校准;先校正可见光光轴与机械回转轴的平行性,再保证激光光轴与机械回转轴的平行性,最终保证可见光光轴与激光光轴的平行性。试验结果表明,该校准方案精度高,指标优于0.1 mrad,可用于实际工程装调。     

Development of an optical sensor for dynamic monitoring of off-round and eccentric errors of cylindrical parts

An optical angular deflection sensor has been implemented to assess the shape and axis position of rotating cylindrical parts. The deviation of the shape from the nominal circular cross-section (the off-round error) and the departure of the rotation axis from the geometric axis of the parts (the eccentric error) are determined. The technique is simple and inexpensive, with acceptable accuracy for mechanical engineering, is capable of monitoring rotating parts and has the potential to gauge parts on the production line.     

定轴转动细杆在轴处不受力的条件

本文给出了定轴转动细杆在不同位置上同时受到多个冲力打击时 ,轴不给细杆附加约束力的条件     

Stationary thread glow discharge

On the basis of new experimental results showing that a uniformly and slowly rotating regular thread is almost quasi-neutral and is difficult to influence by an external magnetic field, relations were derived which explain these phenomena. The angular frequency of rotation of a thread, derived from the equation of continuity, the equation for the momentum and from Poisson's equation, is dependent on the axial macroscopic velocity of negative ions, as has already been proved. At the same time conditions were obtained for the distribution of the space charge in the thread. It is seen that the quasi-neutrality is only very slightly disturbed.The author thanks G. Horváthová and P. Kocian from the department of physics of the electrotechnical faculty in Podbrady for some of the calculations and measurements.     

The mechanics of particles inside a rotating cylindrical mass shell

It is shown that up to the second order in the gravitational constant the effect of a rotating mass shell on a particle moving near its axis is the same as that of a rotating coordinate system. Coriolis force and centrifugal force have, contrary to the case discussed by Thirring[1, 2], the value expected in a rotating reference frame.     

切变模量和转动惯量实验的改进

设计了一种基于垂直轴定理的新型吊钩,对切变模量和转动惯量实验进行了改进,使之成为既可测定金属丝切变模量和环、柱等刚体的转动惯量,又可验证反映转动惯量重要性质的平行轴定理及垂直轴定理的多功能实验仪.     

浅谈定轴转动刚体的动量矩

指出作定轴转动的刚体,对轴上不同的点量矩一般是不同的,进而给出了对轴上任意两点的动量矩之间的关系,并说明其应用。     

极坐标激光直写系统原点定位的实验研究

分析了旋转线性光栅法对准光轴与旋转机械轴中心的理论准确度,实验研究了极坐标激光直写系统的原点定位.在极坐标激光直写系统下进行了圆环线条写入实验,得出了原点定位的准确度,原点定位准确度优于0.5 μm,实验与理论定位准确度基本一致.     

旋转带电球体的转动惯量

对均匀带电球体绕其自身的对称轴作变角速度旋转产生的磁场和感应电场求解，之后计算了这球体对该轴的转动惯量。     

Rotating Minimal Thermodynamic Systems

Minimal rotating thermodynamic systems are addressed. Particle m placed into the rotating symmetrical double-well potential (bowl), providing binary logical system is considered. The condition providing the transfer of the particle from one frictionless half-well to another, and, in this way, the possibility to record 1 bit of information is derived. The procedure of recording turns out to be irreversible; it is impossible to return the particle to its initial state under rotation about the same axis. The same rotating double-well system exerted to the thermal noise is considered. A minimal rotating thermal engine built of the rotating chamber, movable partition, and the particle confined within the chamber is treated. Rotation of the system displaces the partition, thus enabling erasing of one bit information. Erasing of 1 bit of information is due to the inertia (centrifugal force) acting on the partition. Isothermal expansion of the “minimal gas” expectedly gives rise to the Landauer bound. Compression of the “gas” with the rotation around the same axis is impossible and demands the additional axis of rotation. The interrelation between the possibility of recording/erasing information and the symmetry of the system is considered.     

Direct observation of irrotational flow and evidence of superfluidity in a rotating Bose-Einstein condensate

We have observed the expansion of vortex-free, rotating Bose condensates after their sudden release from a slowly rotating anisotropic trap. Conservation of angular momentum, combined with the constraint of irrotational flow, cause the rotating condensate to expand in a distinctively different way to one released from a static (nonrotating) trap. This difference provides clear experimental evidence of the purely irrotational velocity field associated with a superfluid. We observed this behavior in absorption images taken along the rotation axis.     

Second shape transition temperature: prolate noncollective to oblate noncollective

Many nuclei have a temperature interval where the rotation of a hot spherical equilibrium shape generates a prolate equilibrium shape rotating around its symmetry axis.     

GNSS天线连接器同轴度误差测量技术

为测量GNSS天线连接器同轴度误差,构建了连接器分段旋转数学模型,提出了一种水平转台和机器视觉结合的非接触式测量方法,搭建测量装置并进行了测量实验.分析连接器运动方式和同轴度误差测量方法,确定各轴线之间的偏移关系,建立同轴度误差数学模型和测量模型.搭建测量装置,相机安装在水平转台上方,光轴平行于水平转台轴线.旋转水平转台,使用相机捕捉转接螺杆端面圆心位置并拟合轨迹,完成测量装置同轴度误差自标定.将连接器安置在水平转台上,旋转水平转台,测量连接器顶部螺纹杆轴线相对水平转台轴线的偏移.旋转连接器的承载器,测量连接器顶部螺纹杆轴线相对承载器轴线的偏移.最终,综合各轴线的偏移关系得到连接器同轴度误差的最大值.实验结果表明,测量装置对GNSS天线连接器同轴度误差的测量标准差为9μm,单次测量结果的扩展不确定度U=30μm(k=2),满足GNSS天线连接器0.1 mm至1 mm量级的同轴度误差的测量需求,使用连接器同轴度误差修正GNSS超短基线测量结果,可以显著提升基线测量精度.     

黑洞阴影在SSD中的位置和形状

假设旋转的黑洞在标准吸积盘内,在吸积盘的内边界等于最后稳定轨道的情况下,画出黑洞阴影在吸积盘的图像.通过定性和定量分析黑洞的形状和位置,发现对于相同质量的黑洞,黑洞阴影的大小及形状与黑洞的自旋参量有关.旋转黑洞阴影的形状和位置与它的旋转轴是不对称的,通过研究旋转轴与黑洞阴影的位置关系来确定黑洞的质量中心的位置及黑洞的旋转参量.     

分光计中望远镜的调节原理

探讨了分光计中对望远镜进行各步调节的原理,解释望远镜聚焦无穷远、望远镜光轴垂直于仪器转轴及分划板竖直准线平行于仪器转轴的调节原理,并建议在分划板竖直准线上平均划分出尽可能小的刻度,以便减少对光轴的调节次数。     

Optical pumping nuclear magnetic resonance system rotating in a plane parallel to the quantization axis

A model of an optical pumping nuclear magnetic resonance system rotating in a plane parallel to the quantization axis is presented. Different coordinate frames for nuclear spin polarization vector are introduced, and theoretical calculation is conducted to analyze this model. We demonstrate that when the optical pumping nuclear magnetic resonance system rotates in a plane parallel to the quantization axis, it will maintain a steady state with respect to the quantization axis which is independent of rotational speed and direction.     

匀质三角形板和边框的转动惯量

质量均匀分布的物体相对质心轴的转动惯量,通常是由它的几何量表示,这称为转动惯量的几何表示．如果给定物体的顶点坐标,它相对任意轴的转动惯量可以由这些顶点坐标表示,这称为转动惯量的代数表示．由转动惯量的平行轴定理,得到杆和三角形板相对任意转轴转动惯量的代数表示．作为简单应用,得到三角形边框相对质心轴转动惯量的几何量表示．