Motion and Splitting of Vacuum Arc Column in Transverse Magnetic Field Contacts at Intermediate—Frequency

Arc motion and splitting of vacuum arc at intermediate frequency（400-800 Hz） were investigated under transverse magnetic field（TMF）.The experiment was performed on cup-type TMF contacts with contact diameter of 40 mm and a contact gap of 4 mm in a single-frequency circuit.With high-speed photography we characterized the arc appearance at different arc currents from 3.3 kA-rms to 10 kA-rms at intermediate frequencies.As arc current increases from3.3 kA-rms to 10 kA-rms the arc appearance changes obviously.When current value is 3.3 kArms（current frequency 400-800 Hz）,there is almost no splitting arc;when the current exceeds5 kA-rms（current frequency 400-800 Hz）,the arc rotates at a speed above 20 m/s,accompanied by an observable splitting arc.The splitting arc could be observed at different frequencies and the arc-voltage had no noises when splitting occurred.The motion direction and the velocity of arc column were studied.Finally,the formation of a split arc was discussed.

A wind tunnel investigation on the transverse motion of aeolian sand

A wind tunnel experiment was performed to investigate aeolian grain motions in the transverse direction, which is perpendicular to the incoming flow and parallels the sand bed. The trajectories in the horizontal plane were recorded by high-speed camera. Statistical analysis of 630 trajectories shows that both the motion orientation and the time-averaged speed follow Gaussian distributions. An exclusive method was used to analyze the driving mechanism. It was concluded that the three-dimensional turbulent air flow, rather than the spin of grain or grain-bed collisions, controls the transverse motion.

Development of a New Flux Switching Transverse Flux Machine with the Ability of Linear Motion

This paper proposes a new rotary flux switching transverse flux machine with the ability of linear motion(FSTFMaLM),in which both the stator and the rotor cores are made by using soft magnetic composite(SMC)materials.With the special design pattern,for the rotary motion model,the proposed machine can combine both the advantages of the flux switching permanent magnet machine(FSPMM)and the transverse flux machine(TFM).It can output with relatively high torque density,and as there is no windings or the magnets on the rotor cores,the proposed machine can operate in the high speed region to improve the output power.With the adoption of the SMC materials,the manufacturing of this machine can be quite easy.By stacking the rotor core together and prolong it with the determined length in the axial direction,in addition with the special control algorithm,the proposed machine can have the ability of the linear motion.In this paper,the operation principle of this machine has been explained and the design methods are also presented.To seek the better performance,the main dimension of the machine is optimized,and for the performance evaluation,the finite element method(FEM)is adopted.The proposed machine can be used for the electric driving systems,robotic systems or other applications where the linear motion ability is required.

A Hydrodynamic Model Including Phase Transition and the Thermal Motion Induced Transverse Momentum Distributions in p-p Collisions at LHC Energies

It is widely believed that the matter created in p-p collisions exhibits a similar collective behavior as that formed in heavy ion collisions. In this paper, by taking into account the effects of thermal motion, the transverse momentum distributions of identified charged particles are discussed in the scope of the hydrodynamic model including phase transition. The theoretical model gives a good description to the data collected in p-p collisions at LHC energies for the transverse momentum up to about .

Non-axisymmetrical vibration of elastic circular plate on layered transversely isotropic saturated ground

The non-axisymmetrical vibration of elastic circular plate resting on a layered transversely isotropic saturated ground was studied. First, the 3-d dynamic equations in cylindrical coordinate for transversely isotropic saturated soils were transformed into a group of governing differential equations with 1-order by the technique of Fourier expanding with respect to azimuth, and the state equation is established by Hankel integral transform method, furthermore the transfer matrixes within layered media are derived based on the solutions of the state equation. Secondly, by the transfer matrixes, the general solutions of dynamic response for layered transversely isotropic saturated ground excited by an arbitrary harmonic force were established under the boundary conditions, drainage conditions on the surface of ground as well as the contact conditions. Thirdly, the problem was led to a pair of dual integral equations describing the mixed boundaryvalue problem which can be reduced to the Fredholm integral equations of the second kind solved by numerical procedure easily. At the end of this paper, a numerical result concerning vertical and radical displacements both the surface of saturated ground and plate is evaluated.

掘进机横摆作业截割头运动参数的优化设计

掘进机是煤矿开采中重要的设备,在掘进过程中,截割头受到煤岩的冲击等作用,受到较大的阻力.横摆作业工况下,截割头的转速及横摆速度对掘进机截割的效率及能耗等具有直接的影响作用.基于此,采用序列二次规划算法对截割头的运动参数进行优化计算.结果表明,对截割头的转速及横摆速度进行优化后,其截割阻力及推进阻力具有明显的降低,可以提高掘进截割的效率,可以为掘进机的设计使用提供参考指导.

胫骨横向骨搬移手术对糖尿病足患者患肢血流动力学状态、血管血运情况及运动功能的影响

目的分析胫骨横向骨搬移手术治疗糖尿病足的价值。方法回顾性选取2017年3月至2021年10月广州市增城区新塘医院及南方医科大学南方医院收治的74例重度(3~4级)糖尿病足患者作为研究对象,按照治疗方式分为研究组(胫骨横向骨搬移手术,n=40)与传统组(传统清创负压引流术,n=34),记录两组患者双侧动脉血流动力学指标,比较两组患者运动神经传导速度(MCV)与感觉神经传导速度(SCV)、运动神经潜伏期(LAT)。结果术后3个月,研究组患侧股总动脉、腘动脉、胫后动脉、足背动脉患侧血流量高于传统组,血管阻力指数低于传统组,胫神经、腓神经MCV、SCV高于传统组,LAT低于传统组,差异有统计学意义(P<0.05)。结论胫骨横向骨搬移术较传统清创负压引流更能改善糖尿病足患肢血流动力学,重建患肢血运,更利于患肢运动功能恢复。

A study of a slim compact piezo inertia actuator

Most previously reported inertia actuators suffer from the problems of low speed and large size.To overcome these shortcomings,this study proposes a slim compact piezo inertia actuator based on the principle of stick–slip drive.Actuated by the transverse motion of a cantilever beam forming part of a monolithic elastomer,this actuator achieves a high velocity.The construction and basic operating principle of the actuator are discussed in detail.Commercial finite element analysis software is employed to determine the appropriate geometry for the monolithic elastomer.To study the actuator’s mechanical characteristics,a prototype is fabricated and a series of experimental tests are performed.According to the results of these tests,the maximum velocity and maximum load force are about 24.03 mm/s and 1.96 N,respectively,and the minimum step size is about 0.47μm.It is shown that the inertia actuator based on a monolithic elastomer with a cantilever beam not only has a slim compact structure,but also exhibits good output characteristics.

Optical control of transverse motion of ionization injected electrons in a laser plasma accelerator

We demonstrate an all-optical method for controlling the transverse motion of an ionization injected electron beam in a laser plasma accelerator by using the transversely asymmetrical plasma wakefield. The laser focus shape can control the distribution of a transversal wakefield. When the laser focus shape is changed from circular to slanted elliptical in the experiment, the electron beam profiles change from an ellipse to three typical shapes. The three-dimensional particlein-cell simulation result agrees well with the experiment, and it shows that the trajectories of these accelerated electrons change from undulating to helical. Such an all-optical method could be useful for convenient control of the transverse motion of an electron beam, which results in synchrotron radiation from orbit angular momentum.

银质针导热疗法对第三腰椎横突综合征患者的作用效果

目的探讨银质针导热疗法在第三腰椎横突综合征中的应用效果。方法选择2019年10月至2022年2月于漯河市中医院治疗的116例第三腰椎横突综合征患者,以随机数字表法分组,各58例。常规组接受常规西医治疗,银质针导热组在常规西医治疗同时接受银质针导热疗法治疗,两组患者均连续治疗1个月,治疗前、后观察患者肿瘤坏死因子α(TNF-α)、丙二醛(MDA)、超氧化物歧化酶(SOD)、白细胞介素-17a(IL-17a)、单核细胞趋化蛋白-1(MCP-1)、总抗氧化能力(T-AOC)水平,检测患者腰椎后伸、前屈活动度及肌力,治疗前、后给予患者数字疼痛评分法(NRS)、腰椎Oswestry功能障碍指数(ODI)评价,比较两组的临床疗效。结果治疗后,银质针导热组患者IL-17a、MCP-1、TNF-α、MDA水平较常规组低(P<0.05),SOD、T-AOC水平较常规组高(P<0.05);银质针导热组腰椎后伸、前屈活动度及肌力较常规组高(P<0.05),ODI、NRS评分较常规组低(P<0.05)。银质针导热组患者总有效率(98.28%)较常规组高(87.93%)(P<0.05)。结论银质针导热疗法治疗第三腰椎横突综合征患者可降低炎症因子水平,抑制机体炎症,清除氧自由基,减少氧化应激损伤,缓解腰部疼痛,提升腰椎活动度和肌力,改善腰部功能,提升患者生活质量,临床效果较好。

两向自由度低质量比圆柱体涡激振动的数值计算

使用RANS方程求解器结合SST k-ω湍流模型对低质量比弹性支撑圆柱体在流向和横向(两向)的运动进行了数值计算,着重研究了限制流向运动与否对圆柱体横向振幅的影响。通过对不同质量比圆柱体在较大折合速度范围内的计算,得出了当质量比低于m*cri=3.5时,两向自由度的圆柱体比限制流向运动的圆柱体能产生更大的横向振幅。数值计算结果与最近物理实验结果进行了详细的比较和讨论。

回转窑内滚动状态下颗粒横向运动的影响因素的实验研究

回转窑内物料颗粒的横向运动使物料的传热和传质得到加强,其研究对于回转窑的优化设计和运行是十分重要的。本文在数学模型的基础上采用数码摄像的方法对多种物料颗粒在旋转筒体内的横向运动进行了实验研究,考察了筒体直径、旋转速度、料床内物料的动态休止角等参数对于泻落层厚度、颗粒运动速度、流量以及物料在料床表面停留时间的影响,并通过实验验证了数学模型。

花垣铅锌矿床成矿流体特征及动态

花垣铅锌矿床是近年来发现的产于下寒武统清虚洞组藻灰岩 -鲕粒灰岩中的大型密西西比型 (MVT)铅锌矿床。根据矿床中大量流体包裹体的详细研究 ,成矿流体为高盐度的低温热卤水 ,流体气相组分中 ,H2 O占有主要部分 ,CO2 +CH4 约为 5% ,lgf O2 稳定在 - 4 8.0～ - 4 9.0 0之间 ,p H为 4 .3～ 5.8,Eh为 - 0 .0 7～ - 0 .1e V,此外 ,流体组分中 ,钠离子的含量大于钾离子 ,钙离子大于镁离子 ,而氯离子大于氟离子 ,这一特点是 MVT矿床所共有的 ,但 Na+ / K+值较低而Ca2 + / Mg2 + 比值较高 ,不同于美国的许多 MVT矿床 ,流体中 K+ 离子较高的原因之一 ,在于部分矿体的寄主岩石中 K+含量较高 ,对流体的成分产生了影响。此外 ,流体的氢、氧同位素组分表明 ,流体来源与建造水有关 ,后期有大气降水加入。大量数据证明 ,在矿床范围内 ,流体的温度与 CO2 、CH4 、K+、Na+、Ce2 +的含量 ,具有从北向南同步下降的特点 ,表明在矿床中 ,流体的运动方向是由北而南顺层侧向流动的 ,矿区外围可能也具有这种运动趋势。

船舶横稳性高对操纵运动影响的四自由度仿真

基于分离建模思想建立了船舶四自由度操纵运动方程,将作用于船舶的作用力分解为船体惯性力、船体粘性力、螺旋桨推力和舵力,运用四阶龙格库塔数值方法求解了船舶操纵运动方程,探讨了初稳性高对船舶回转运动的影响,并对S-175大型船在静水中的回转运动进行了数值仿真。数值结果表明:随着初稳性高的增大,船舶的回转直径增大,稳定横倾角则逐渐减小,并且航向对操舵的响应存在一定延迟效应。

多楔带传动系统轮——带振动的实测与计算方法研究

以一典型的由驱动轮、从动轮、张紧器和多楔带组成的三轮—带系统为研究对象,并对多楔带传动系统中轮的旋转振动、带的横向振动、张紧臂的摆动角度进行实测。针对三轮—带传动系统轮—带耦合振动,建立相应的数学模型。模型中,将带简化为轴向运动弦线,计算时应用Garlerkin法将带的时间—空间连续方程离散成为时间函数与空间函数之积。计算从动轮旋转角度波动、从动轮—带的滑移率、带段中点的横向振动位移、带横向振动的固有频率,并和试验值进行对比分析。结果表明,计算值与实测值吻合较好,从而计算模型和测试方法的正确性得到验证。该测试方法和计算方法对诸如发动机前端附件驱动系统等复杂的多楔带附件驱动系统动态特性的设计具有参考价值。

回转窑截面物料运动及力链结构的数值试验

采用离散单元法从颗粒尺度建立回转窑内物料的运动模型,以球形沙粒为例,通过数值计算,研究回转窑截面上物料的运动模式和力链结构。以Froude数、物料填充角、窑壁摩擦因数为变量,模拟物料的滑移、塌落、滚落、泻落、抛落和离心6种运动模式,模拟结果与实验观测结果相符。研究结果表明:回转窑内物料力链由表层弱力链区域(约占料层厚度10%)和底层强力链区域组成;滑移、塌落、滚落和泻落4种模式中,底层强力链结构稳定,颗粒之间相对静止,表层弱力链断裂和重组频繁,具体运动模式由窑转速和表层力链断裂重组的速度决定;实际转速中,泻落模式的物料颗粒碰撞最强烈。

低速水下航行器横向-横滚操纵性研究

文中对低速水下航行器的横向-横滚操纵性进行了一定的研究。建立了水下航行器横向-横滚扰动方程,提出了水下航行器的横向-横滚 K-T 分析指数,并运用所建立的 K-T 分析指数分析了A、B两型水下航行器的操纵性能。

对称间隙下轧辊的横向振动特性研究

基于广义Hertz接触理论,建立了含对称间隙的轧辊横向碰撞振动模型,采用四-五阶Runge-kuta法进行了数值求解,分析不同辊轧速度、辊轧量、间隙、导板安装刚度下的系统时域波形图、相图、庞加莱截面,研究了轧辊与导板间的非线性振动特性。结果表明:当频率比Ω=3、辊轧工作过程中的间隙d=0.04 mm、无量纲参数T=13、导板安装刚度k_2=8×10~4N/mm时,系统由碰撞逐步转变为黏滞振动运动状态;辊轧量和间隙对系统的非线性影响较大,辊轧量、间隙越大,系统的黏滞运动越明显;辊轧速度和导板安装刚度对系统的非线性影响较弱;系统在各参数可调范围内均处于混沌运动状态。

基于嵌入式工业触摸屏的提花横移控制系统

文中介绍了基于嵌入式工业触摸屏的提花横移控制系统的控制原理、系统组成、硬件和软件的设计。硬件主要由工业触摸屏和伺服系统组成,其中工业触摸屏采用嵌入式技术,以S3C2416 ARM9芯片为核心,集成了输入输出口,是功能丰富的一体控制器。软件由触摸屏人机界面和底层程序构成,分别由HMI软件和ADS1.2应用软件设计完成。实际应用表明:系统自动化程度高、人机交互性好、可靠性高。

惯性加速度计横向灵敏度测量方法及特性分析

随着现代武器打击精度的提高,加速度计的横向输出误差对惯性导航系统有着一定的影响,所以研究加速度计的横向灵敏度可以有效地提高武器的导航定位精度。文中主要介绍了离心法测量横向灵敏度,采用以DSP控制器为核心的运动控制系统来确保离心机的稳速控制,介绍了两种离心机测量横向灵敏度的方法并将测试结果用Matlab分析处理。