人体关节部位运动轨迹测量仪的研制

步态分析是当代生物医学工程发展中的一项重要技术，本文介绍的人体关节部位运动轨迹测量仪采用超声测距、脉冲调制、区域编码等方法，能精确重建人体步行时各关节部位的三维空间运动轨迹，该系统具有使用方便、快速、精确等优点，并具有较高的性能价格比。     

人体关节部位运动轨迹测量仪的研究

步态分析是当代生物医学工程发展中的一项重要技术，本文介绍的人体关节部位运动轨迹测量仪采用超声测距、脉冲调制、区域编码等方法，能精确重建人体步行时各关节部位的三维空间运动轨迹，该系统具有使用方便、快速、精确等优点，并具有较高的性能价格比。     

提高超声步态检测系统精度的研究

本研究组曾报告了超声下肢步态仪的成功研制，而本文工作即是在此基础上针对影响超声步态仪精度的多种因素进行详细研究之后提出并实施了若干措施而有效地将超声步态仪的精度由０．２％提高到０．１％，本文结果证明，这些措施的应用不仅有利于超声步态仪检测精度的提高，而且也将有助于仪器中新功能的实现。     

提高超声步态仪精度的方法研究

在步态仪中利用接收的超声信号峰值信息来校正前沿定时产生的误差,可以提高步态仪的精度。给出了实测数据和修正曲线。     

磁四极透镜的Lie代数分析--三级近似

用Ｌｉｅ代数方法分析了带电粒子在四极透镜中的运动，得到六维相空间中粒子轨迹的三级近似解，并包含了运动的相对论效应。当需要时，还可以推展到更高级像差。     

二极磁铁的三级Lie映射

用Ｌｉｅ代数方法分析了带电粒子在二极磁铁中的运动，得到在六维相空间中相对论凿子的三级近似轨迹。     

一种基于Directshow的实时运动监测系统的实现

采用Directshow框架,对运动检测的传统模型提出了简化和改进,设计了一个功能较完整的运动检测Fitler,用在网络视频监控项目中,得出了实验结果.     

非线性相移因子与渡越能量附近粒子的动力学行为

束流穿越渡越能量后动量分散增加,束流品质退化。在经典力学框架内和小振幅近似下,考虑到相移因子的二阶非线性、射频噪声和辐射衰减的影响,把同步加速器的粒子同步运动方程化为具有阻尼项、受迫项的二阶非线性微分方程。对系统的相平面特征和振幅响应进行了数值分析;用摄动法讨论了系统的稳定性及1/3共振线附近粒子的运动行为:分析了系统的跳跃现象和系统的临界条件。结果表明,零次相移因子越大和三阶非线性越小系统越稳定。     

弱耦合体系流致振动计算方法

弱耦合体系的流致振动的流体作用力可分成与结构运动有关的流体力和与结构运动无关的流体作用力.与结构运动有关的流体作用力可用结构的惯性力、阻尼力和刚度力的线性表达,与结构运动无关的流体力用CFD计算流场压力获得.本文介绍了一种计算弱耦合体系流致振动的方法,用该方法计算了秦山Ⅱ期1∶5模型吊篮,计算的结果和实验的结果保持在3.1倍范围内.因此,该方法可用于流致振动实验前的预估.     

驻波边耦合腔电子直线加速器中束的聚焦

本文利用网格法计算腔特性所得资料计算了驻波边耦合腔电子直线加速器中电子的径向运动,分析了腔的电透镜特性,简单地考虑了空间电荷效应。分析和计算的结果表明,在短的加速器中,为改善束的聚焦特性,应采用适当的负注入角度;在较长的加速器中,可以用一个短磁透镜实现束的聚焦。     

基于PLC的立体车库监控系统的设计

针对国内车辆的迅速增加,停车难的问题日益明显及停车场占地面积大,安全性差等问题,提出了解决这一问题的有效途径—现代化先进的立体车库.立体车库是一种以单层平面停车场为核心、多平面的空间停车车库,通过可编程控制器控制车位空间位置的变动,使车位能够实现平面到空间的转化,实现多重单层平面停车的功能.升降横移式立体车库利用托盘来...     

Multiperiodic states and bifurcations in bunch lengthening by alocalized impedance in electron storage ring

The equilibrium particle distribution of a bunch in an electron storage ring is investigated using a localized constant wake function. It is shown that, under some conditions, stable multiperiodic states can exist simultaneously. When moving around the parameter space, the system can show bifurcation phenomena which is not always reversible. We study this behavior using the Gaussian approximation and compare the results with multiparticle tracking. The results show qualitative agreement     

Estimation of maximum coated particle fuel compact packing fraction

This work develops an analytic fuel fraction packing model for a high temperature gas cooled reactor fuel compact fabricated from overcoated particles of a single size. The model includes the effects of one dimensional compression and finite matrix grain size. One dimensional compression limits the maximum fuel packing fraction to about 48% for the pressed compact in this single sized particle system. This limit is due to two effects. The first is that the process of die loading limits the pre-compression packing configuration to one that is stable under gravity, which is not the most space efficient one. The second effect is due to the one dimensional compression which reduces only the axial dimension of the particle lattice rather than uniformly compressing the lattice. The die wall can also limit the maximum packing fraction by preventing the nearby particles from moving into a more space efficient configuration.     

Development of a swim-type ROV for narrow space inspection

The swim-type remotely operated vehicle (ROV) for inspection of narrow spaces in nuclear power plants has been developed. Many structures are crowded in a confined space at regular intervals in the bottom area of a reactor. So, the thickness of the ROV shape is an important design point to ensure that the ROV can move in the space. The developed ROV has a three-dimensional swimming mechanism using six thrusters, three cameras for observing the position while moving and for making inspections easily, and a localization system. The localization system combines two elements: a gyroscope to detect the progression direction; and a slit laser that detects the progression distance using the optical cutting method. The localization method is called the modified inertial navigation (MIN) method and it was evaluated in a mock-up examination. The ROV was able to move smoothly using the MIN method and its position could be detected without making a mistake in the route followed.     

三维空间液滴运动模型数值解法研究

提出了数值求解三维空间液滴运动模型的算子分裂算法（OS算法），并与常用的显式单步长Runge-Kutta（RK）算法进行了比较。简述了三维空间液滴运动模型的具体形式，提出了求解该模型的OS算法，以求解不同直径液滴在波形板汽水分离器内的运动轨迹作为算例，从OS算法的相容性、稳定性、计算精度和计算效率（CPU耗时）等方面，与4级4阶显式单步长RK算法进行了比较。结果表明，OS算法所构造的离散格式与液滴运动模型相容，采用此算法计算得到的液滴运动轨迹与RK算法得到的结果相似，而OS算法的稳定性和计算效率均优于RK算法。因此，OS算法的提出为数值计算波形板的分离效率提供了较为稳定、高效的算法。     

MCNP6 moving objects part I: Theory

Various radiation transport simulations pertaining to active and passive interrogation, medical physics, space applications, and other disciplines involve the motion of objects. In some instances radiation is emitted from within an object, while in other cases radiation is incident on an object. In our latest innovation for MCNP6, we introduce the capability to perform self-contained radiation-transport simulations involving moving objects. Object motion is treated using rigid-body kinematics as characterized by rectilinear translation, curvilinear translation, and curvilinear rotation along motion segments. Individual motion segments can be linked together to create complicated paths. Simulations can accommodate the simultaneous motion of up to 1000 moving objects. The moving-objects feature is designed for source-mode (“SDEF”) simulations, and includes the capacity to model moving sources comprised of prompt particles as well as delayed neutrons and gammas. The motion of objects and sources can be simulated by constant velocity, acceleration or deceleration, or simple relocation. In addition, the MCNP6 plot utility has been upgraded to permit animated plots of geometry as it evolves in time. The moving-objects feature may be executed in either serial mode or parallel mode using MPI. In this article we delineate the formulations and code modifications required in MCNP6 to implement the new moving-objects capability. In the companion article we illustrate the capability using several simulations. The moving-objects innovation will bring enhanced realism to simulations that exhibit motion.     

Busbar arcs at large fusion magnets: Conductor to feeder tube arcing model experiments with the LONGARC device

Electric arcs moving along the power cables (the so-called busbars) of the toroidal field (TF) coils of ITER may reach and penetrate the cryostat wall. Model experiments with the new LONGARC device continue the VACARC (VACuum ARC) experiments that were initiated to investigate the propagation and destruction mechanisms of busbar arcs in small scale [1]. The experiments are intended to support the development and validation of a numerical model. LONGARC overcomes the space limitations inside VACARC and allows also for advanced 1:3 (vs. ITER full scale) model setups. The LONGARC device and first results are presented below.     

Investigation of space-dependent neutron-flux fluctuation excited by a strong absorber

The time response of neutron flux to the sudden displacement of an absorber in a reactor is studied by 1-D one-group treatment, and by applying the method to an example, it is shown that the flux depression around the absorber follows rapidly the displacement of the absorber, but there is some time delay in reaching a steady flux in regions farther from the absorber.The space dependence of the neutron noise induced by vibrating a strong absorber is studied by considering the flux depression which follows the moving absorber. The correction to the amplitude of the peak for the vibrating strong absorber is derived. It is shown that the bi-frequency term in the first order of displacement of the absorber vanishes because of the characteristic of the Green's function.     

The influence of magnetic field on the beam quality of relativistic electron beam long-range propagation in near-Earth environment

In recent years,it has been proposed to use satellite-mounted radio-frequency(RF)accelerators to produce high-current relativistic electron beams to complete debris removal tasks.However,when simulating the long-range propagation(km-range)process of the electron beam,it is difficult to directly use the particle-in-cell method to simultaneously consider the space charge effect of beam and the influence of the geomagnetic field.Owing to these limitations,in this paper,we proposed a simplified method.The ps-range electronic micropulses emitted by the RF accelerator were transmitted and fused to form a ns-range electron beam;then,combined with the improved moving window technology,the model was constructed to simulate the long-range propagation process of the relativistic electron beam in near-Earth environment.Finally,by setting the direction of movement of the beam to be parallel,perpendicular and at an inclination of 3° to the magnetic field,we analyzed and compared the effects of the applied magnetic fields in different directions on the quality of the beam during long-range propagation.The simulation results showed that the parallel state of the beam motion and magnetic fields should be achieved as much as possible to ensure the feasibility of the space debris removal.     

无保护失流条件下SFR液体悬浮式PSS移动体的运动及动力特性研究

分析了钠冷快堆（SFR）液体悬浮式非能动停堆组件（PSS）移动体在下落过程中所受水力阻力及其计算方法。根据PSS内部流体网络，对移动体悬浮及下落过程中的流量分配和水力阻力分布进行了分析和建模，使用准稳态结合瞬态修正的方法对移动体运动过程进行了计算。分析了移动体在无保护失流条件下下落运动的时程。结果表明：移动体在下落过程中的速度和加速度逐渐增大、所受水力阻力减小；移动体下落0.588 m的时间为6.68 s。移动体下落时间的计算结果满足初步设计要求，可作为分析计算PSS落棒时间的参考。