CFETR偏滤器模块远程操作支撑结构设计与仿真分析

根据远程操作的要求，研究了适合CFETR偏滤器模块远程操作的内外支撑结构设计：内支撑是球形结构，外支撑是齿轮齿条结构，即齿轮齿条设计方案。在虚拟环境中将设计的支撑结构进行了仿真，验证了该结构在安装过程中的可行性。结果表明，所设计的齿轮齿条方案能满足CFETR偏滤器模块的远程操作要求，在该支撑的作用下，偏滤器模块在真空室里能够被固定约束住。     

Noncontact racK and pinion powered by the lateral Casimir force

The lateral Casimir force is employed to propose a design for a potentially wear-proof rack and pinion with no contact, which can be miniaturized to the nanoscale. The robustness of the design is studied by exploring the relation between the pinion velocity and the rack velocity in the different domains of the parameter space. The effects of friction and added external load are also examined. It is shown that the device can hold up extremely high velocities, unlike what the general perception of the Casimir force as a weak interaction might suggest.     

Cooperative acceleration of task performance: Foraging behavior of interacting multi-robots system

We study the effectiveness of cooperative behavior in a society of interacting agents. After reviewing the problem and defining the concept of swarm intelligence, we examine collective behavior of many-body active clusters through a task to gather pucks in the field. In this study, we used a robot with a simple structure which has a driving system and the simplest interacting means; a light and some sensors. The effectiveness of group behavior was studied under various (homogeneous, localized) puck distributions with real experiment, simulation, and analysis. To evaluate the efficiency of group behavior, we examined the scaling relation between the task completion time and the number of robots, and the relation between the interaction period and the efficiency of group. We found that a cooperation between agents by a simple interaction is very efficient in enhancing the performance of the group compared with independent individuals.     

Flow-induced noise analysis for 3D trash rack based on LES/Lighthill hybrid method

A trash rack is used to obstruct dirt in a flow. As it is on the outside of the hull of a ship, such flow-induced noise cannot be ignored. This paper focuses on a hydrodynamic noise study of the trash rack installed on the inlet of pipelines to estimate the noise produced by the turbulent flow. A hybrid method of combining Large-Eddy Simulation (LES) and the Lighthill’s acoustic analogy theory simulate the flow-induced noise for a three-dimensional pipeline. The results of the simulation agree well with the experimental results available in the open literature. Following this, the hydrodynamic noise of flow through a three-dimensional pipeline with different types of trash racks is studied in order to determine the best form. For this objective, the flow and sound properties in different simulation models are analyzed and a low noise type of trash rack is proposed based on some general indexes.     

光束控制系统组件化仿真及运动解耦方法研究

利用激光系统组件化仿真软件构建了光束控制系统的组件化仿真框架,对几何/波动光学传输、光束定向器机架与其内部光学元件的耦合运动进行了仿真,提出了目标脱靶量数据和传感器图像自动更新、光束定向器机架与其内部多块快速倾斜镜控制驱动量自动解耦的数值仿真新方法,并在动态跟踪控制可视化过程中完成了光束定向器机架、多块快速倾斜镜驱动控制以及光学传输成像的仿真,满足了光束控制系统建模仿真的普适性、灵活性、易用性设计目标。最后,大气传输校正联合仿真实例证明:利用精跟踪、自适应光学技术能有效抑制大气低频扰动幅值,校正高频扰动的影响。     

Massively parallel low-cost pick-and-place of optoelectronic devices by electrochemical fluidic processing

We describe a novel electrochemical technique for the nonlithographic, fluidic pick-and-place assembly of optoelectronic devices by electrical and optical addressing. An electrochemical cell was developed that consists of indium tin oxide (ITO) and n -type silicon substrates as the two electrode materials and deionized water (R = 18 MOmega) as the electrolytic medium between the two electrodes. 0.8-20-microm-diameter negatively charged polystyrene beads, 50-100-microm-diameter SiO(2) pucks, and 50-microm LED's were successfully integrated upon a patterned silicon substrate by electrical addressing. In addition, 0.8-microm-diameter beads were integrated upon a homogeneous silicon substrate by optical addressing. This method can be applied to massively parallel assembly (>1000 x 1000 arrays) of multiple types of devices (of a wide size range) with very fast (a few seconds) and accurate positioning.     

Analysis of an internal crack of pressure pipeline using ESPI and shearography

In this study, shearography and ESPI have been used for quantitative analysis of an internal crack of pipeline and both of them have proved to be suitable to qualitatively detect inside crack. However, shearography needs several critical? factors including the amount of shearing, shearing direction and induced load for the quantitative evaluation of the inside crack. In this study, the factors were optimized for the quantitative analysis and the size of cracks has been determined. Although the critical? factors in shearography have been optimized, it is difficult to determine the factors exactly because they are related to the details of cracks. On the other hand, ESPI is independent of the details of a crack and only the induced load plays an important role. The out-of-plane displacement was measured under the optimized load and the measured results were numerically differentiated, which resulted in an equivalent to the shearogram. The size of cracks can be determined quantitatively without any detail of a crack.     

基于旋转式反射镜的飞行视觉系统设计

在MEMS麦克风贴片工艺中,真空吸嘴吸取MEMS芯片以后需要进行芯片位姿的精确校正。为实现高速高精度贴片功能,提出了一种基于旋转式反射镜的飞行视觉系统,该方案利用齿轮齿条将吸嘴的升降运动转化为反射镜的旋转运动,通过设计齿轮参数,实现反射镜不干涉吸嘴的拾放功能。当反射镜旋转到与水平位置夹角呈45°时,视觉系统可以获得MEMS芯片的静止的清晰图像,CCD相机采集一幅图像后,在贴片头飞行的过程中,控制系统完成MEMS芯片的位置和角度的校正。实验结果表明,该系统可以获取高质量MEMS芯片图像。该系统结构简单紧凑,成像无失真,不限制贴片头的运动轨迹,显著提高了MEMS芯片的贴片质量和贴片效率,可广泛地应用于贴片机系统中。     

高速电视姿态测量系统室内目标姿态模拟与标定测量

介绍了利用高速电视姿态测量系统对目标姿态进行交汇测量的原理，使用检测架、平行光管以及图形板（刻有不同角度的目标刻线）室内模拟无穷远目标姿态.用高准确度经纬仪对模拟的无穷远目标姿态进行标定、测量结果与采用高速电视姿态测量系统对室内模拟目标的测量结果比较，可知高速电视测量系统姿态角的测试准确度.推导了目标姿态角计算公式，对经纬仪对无穷远目标姿态进行标定的方法进行了准确度分析，得出经纬仪目标姿态角标定的最大误差，并且经过实验进行了验证.     

一种新型YBCO高温超导带材临界电流特性测试方法

针对YBCO高温超导带材临界电流特性,文中基于四引线法,构造了一个集成有背景磁场发生装置的减压降温的低温测量装置。该装置包括一个提供背景磁场的双"E"形铁心线圈磁体;一个可以旋转0—360°的超导带材样本架以及一套可实现减压降温功能的低温测试系统。通过对低温杜瓦内温度、YBCO带材所处背景磁场大小、背景磁场与YBCO带材表面夹角的控制,实现了YBCO超导带材在不同温区、不同磁场及磁场方向下的临界电流特性的测量。这种新颖的测量方法和装置,综合考虑了环境温度、背景磁场和磁场方向变化的具体影响,能够获得较全面的YBCO高温超导带材临界电流性能参数。     

光电经纬仪测角精度分析

测角精度是影响光电经纬仪定位功能的重要因素。为了进一步提高光电经纬仪的测角精度,对测角误差进行详细分析是必要的。从光电经纬仪的总体设计出发,找出了影响测量数据获取、转换、合成中的各项误差源,并详细分析了它们的大小和性质。通过分析光电经纬仪工作原理及结构找出了主要误差源。对机架系统的误差、测角单元误差、电气系统误差、脱靶量误差、大气折射修正误差等主要误差源进行分析计算,并对各单元进行了误差分配。最后,计算了光电经纬仪投影测角精度的均方根值。分析计算结果显示:通过精心设计、加工、检测,修正可使一部分误差减小甚至忽略,但机架系统的误差、测角单元误差、脱靶量误差对测角精度的影响仍很显著;在当前工艺水平下,光电经纬仪事后空间指向精度可以达到2。     

Active-passive vibration absorber of beam-cart-seesaw system with piezoelectric transducers

In contrast with fully controllable systems, a super articulated mechanical system (SAMS) is a controlled underactuated mechanical system in which the dimensions of the configuration space exceed the dimensions of the control input space. The objectives of the research are to develop a novel SAMS model which is called beam-cart-seesaw system, and renovate a novel approach for achieving a high performance active-passive piezoelectric vibration absorber for such system. The system consists of two mobile carts, which are coupled via rack and pinion mechanics to two parallel tracks mounted on pneumatic rodless cylinders. One cart carries an elastic beam, and the other cart acts as a counterbalance. One adjustable counterweight mass is also installed underneath the seesaw to serve as a passive damping mechanism to absorb impact and shock energy. The motion and control of a Bernoulli-Euler beam subjected to the modified cart/seesaw system are analyzed first. Moreover, gray relational grade is utilized to investigate the sensitivity of tuning the active proportional-integral-derivative (PID) controller to achieve desired vibration suppression performance. Consequently, it is shown that the active-passive vibration absorber can not only provide passive damping, but can also enhance the active action authority. The proposed software/hardware platform can also be profitable for the standardization of laboratory equipment, as well as for the development of entertainment tools.     

气垫导轨实验中滑块的等速和定速发射

设计了由改进的弹射架和定位释放器组成的等速发射装置,实现了气垫导轨实验中滑块的等速发射,并可通过控制滑块初始位置使滑块获得预期发射速度.分析表明滑块发射所获得的速度和初始位置间的关系为近似的线性关系,这一结论和实验结果完全符合.     

On the shape dependence of the tangential Casimir force

The normal and tangential Casimir force for the rack gear is calculated numerically in the case of ideal boundary conditions for the electromagnetic field—perfect reflection on the boundaries. The resulting tangential force appears to be essentially shape-dependent. Relatively small shape variations lead to the essential changes in tangential force, whereas normal force remains almost unchanged.     

可用于建筑结构检测的分布式光纤形变片

本文在光时域反射计(OTDR)和光纤形变片的基础上,提出了一种分布式光纤传感器-分布式光纤形变片.该检测方法属于OTDR的损耗调制法,即通过测量粘贴于光纤形变片上的光纤弯曲损耗来获取测量点的应变量或位移量.作者分别在微位移架和悬臂梁进行了位移检测和应变检测,结果表明该分布式光纤形变片提供了一种可检测应变量与位移量的检测方法.值得注意的是,该分布式光纤形变片的传感网络采用时分复用的总线拓扑,能在一根光纤上同时检测多个检测点的变化.     

可用于建筑结构检测的分布式光纤形变片

本文在光时域反射计（OTDR）和光纤形片的基础上,提出了一种分布式光纤传感器－分布式光纤形变片,该检测方法属于OTDR的损耗调制法,即通过测量粘贴于光纤形变片上的光纤弯曲损耗来获取测量点的应变量或位移量,作者分别在微位移架和悬臂梁进行了位移检测和应变检测,结果表明该分布式光纤形变片提供了一种可检测应变量与位移量的检测方法,值得注意的是,该分布式光纤形变片的传感网络采用时分复用的总线拓扑,能在一根光纤上同时检测多个检测点的变化。     

Optical interconnect based on a fibre bus

A technology which may form a powerful optical interconnection scheme based on a bus architecture is presented. It is shown that the fibre array connectors involved require alignment tolerances comparable to those of present electrical connectors. Further system flexibility can be obtained by tailoring the connector wavelength characteristics. Results of an experiment, where distributed amplification within the backplane of an optical bus was used to compensate for the power removed at the access points, are also presented. This allows a significantly higher number of output ports to be served than would be possible using a passive bus. As an example application, the feasibility of using the technology as the backplane interconnection in a card and rack system is demonstrated. Extension to a switching scheme using the multi-dimensional optical network concept is described.     

基于氨基酸位置特异性的蛋白质Loop区结构预测改进方法

蛋白质loop区的结构预测是理解蛋白质功能的重要一环,而长loop区的结构预测至今还是生物信息学中的难题.目前己经出现了多种loop结构的算法,其中LEAP是预测精度最高的算法之一,但它在长loop区初始主链构象采样上仍有较大的改进余地.本文中我们将蛋白质二级结构预测算法SPINE X与LEAP算法结合起来,构建了新的主链扭转角分布图(拉氏图),在主链初始构象采样中引入氨基酸在蛋白序列中的位置特异性信息,使得初始构象的采样更具针对性,对取自CASP10单链蛋白的loop测试集的分析表明,对长度为10,11,12个氨基酸的长loop区,改进后算法都比原始LEAP算法的预测精度有显著提升.这种引入氨基酸位置特异性从而提高预测精度的思路有望进一步推广至loop结构预测的其他算法.     

A portable laser system for high-precision atom interferometry experiments

We present a modular rack-mounted laser system for the cooling and manipulation of neutral rubidium atoms which has been developed for a portable gravimeter based on atom interferometry that will be capable of performing high-precision gravity measurements directly at sites of geophysical interest. This laser system is constructed in a compact and mobile design so that it can be transported to different locations, yet it still offers improvements over many conventional laboratory-based laser systems. Our system is contained in a standard 19″ rack and emits light at five different frequencies simultaneously on up to 12 fibre ports at a total output power of 800 mW. These frequencies can be changed and switched between ports in less than a microsecond. The setup includes two phase-locked diode lasers with a phase noise spectral density of less than 1 μrad/Hz^1/2 in the frequency range in which our gravimeter is most sensitive to noise. We characterise this laser system and evaluate the performance limits it imposes on an interferometer.     

基于MPPT控制的新型仿生学太阳树灯设计

根据仿生学原理,通过仿造树的结构制作一个树的支架,将太阳能电池板以45°的倾角放在树枝架上,然后通过WS-ALMPPT15控制器和12V/20Ah的铅酸蓄电池、负载(包括直流负载、交流负载)相连。实验测试表明:在产生电力方面,新型树灯在一天内的平均输出功率将比普通的平板太阳能电池板的输出功率输出高出27.3%;此外,新型树灯的输出电压、电流、功率基本上趋于一致,这些都高效地节约了电能。