Exploration of unknown object by active touch of robot hand

This paper proposes a method of exploring the local shape of an unknown object using the force and torque information obtained from active touch. In the first, we present a method to estimate an unknown curvature, using rolling and sliding motion with a force/torque sensor attached to the fingertip of the hand. Then, the normal curvature equation from 2D curvatures is obtained. Finally we present a reconstruction algorithm of local geometry by using a normal curvature equation, which is composed of principal curvatures and principal directions. The method is tested by using a hand-arm system consisting of an industrial robot arm and an anthropomorphic robot hand with 6-axis force/torque sensor. The feasibility of the proposed method is experimentally validated for objects with simple geometries such as cylinder, spheres etc.     

Multidisciplinary design modeling and optimizationfor satellite with maneuver capability

According to the mission of a satellite with maneuver capability, the collaborative optimization (CO) method was introduced for the satellite system design, and the related multidisciplinary design optimization (MDO) model was established. The possessing and needed velocity increments Δv and Δv _{n e e d} were taken as the measurement of maneuvering capability of the studied satellite, which were then combined with total mass of the satellite to form the optimization objective in the systematic level of the MDO problem. The design variables and constraints of the MDO problem dealt with disciplines or subsystems as guidance, navigation and control (GNC), power, and structure, and corresponding engineering analysis models were also built. A program system to solve the MDO problem wasdeveloped by integrating a non-nested CO method, the commercial and user-supplied codes on framework software iSIGHT. The result showed that the satellite performance could be obviously improved, which also indicates MDO technique is feasible and effective for the spacecraft design problem. The modeling and optimization procedure of the work can be referred for further research and engineering design.     

A new model for Brownian force and the application to simulating nanofluid flow

A new expression is proposed to simulate Brownian force based on the experimental measurement results of Brownian motion, which follows white Gaussian noise process. As the time t → 0 and the particle density is equal to the fluid density, the new expression approaches the classical formula of the model used by many researchers. The modified model is validated by theoretical and experimental data. On the other hand, as it origins from the unbalanced force exerted by surrounding fluid molecules, the drag analogy force model is constructed describing the Brownian force, which depends on size-related statistical velocity. Thus, a different expression for the Langevin equation is presented. The present model is applied in simulating flow and heat transfer in a channel utilizing alumina–water nanofluid. Navier–Stokes equations with modified source terms for the continuous flow have been discretized using finite element method. The velocities and temperatures of nanoparticles are determined in the Lagrangian reference frame. The simulation results show that the distribution of nanoparticles inside the channel is obviously unsteady and nonuniform. The fluid velocity and temperature profiles show significant fluctuation feature at low Reynolds numbers (Re). The impact of Brownian motion on the fluid flow is analyzed quantitatively. We have found that for Re < 0.06, the affected intensity increases rapidly.     

Synthesis and properties of acrylonitrile-CR-methyl methacrylate graft copolymer

Graft copolymerization of acrylonitrile (AN) and methyl methacrylate (MMA) onto polychloroprene (CR) was carried out using benzoyl peroxide as initiator. The effects of mole ratio of AN to MMA, reaction temperature, reaction time, solvent, and initiator concentration on the graft copolymerization were examined. It was found that the thermal stability and weatherability of the AN—CR—MMA graft copolymer (ACM) were considerably better than those of CR.     

Numerical study of particle dispersion in the wake of gas-particle flows past a circular cylinder using discrete vortex method

A numerical investigation on the particle dispersion in the wake of particle-laden gas flows past a circular cylinder at Reynolds number of 10⁵ is presented. In the numerical method, the Discrete Vortex Method with the diffusion velocity model is employed to calculate the unsteady gas flow fields and a Lagrangian approach is applied to track individual particles. A dispersion function is defined to represent the dispersion scale of the particle. The distributions of gas velocities and vortex blobs, the trajectories and dispersion functions as well as distributions for particles with various Stokes numbers ranging from 0.01 to 1000 are obtained. The numerical results show that: (1) very small sized particles with St = 0.01 can distribute both in the vortex core and around the vortex periphery, whereas intermediate sized particles with St = 1.0, 10 are distributed around the vortex periphery, and very large sized particles with St = 1000 do not feel the gas flow; (2) only at small Stokes number (St = 0.01, 0.1) the particles do not impact with the cylinder; (3) the particle's dispersion intensity decreases precipitously as St is increased from 0.01 to 10.     

我国传动带工艺装备现状与展望

20世纪90年代中后期我国传动带工业开始大规模地进行包布V带线绳结构化改造，先后开发制造了线绳包胶装备单鼓成机，广泛应用双鼓成型法，开发出第四代线绳成型机，硫化工艺普遍使用径向启闭式硫化罐。对代表传统动带发展方向之一的切边V带，多楔带和同步带，亦生产出短纤维胶片拼接机，DCV多功能成型机等等。硫化工艺要用蒸汽加热加压式硫化罐或蒸汽加热水加压式硫化罐。我国传动带的工装设备现已基本满足制造需求，但仍与国外的先进水平肌不小的差距，今后我国传动带工业要提高现有设备的技术水平，开发急需的生产装备，加快实验设备的国产化。     

智能手机点击劫持攻击检测方法研究

点击劫持通过欺骗用户点击经过伪装的界面元素达到攻击目的。移动互联网环境下,智能手机的屏幕特征、手势识别、HTML5支持度高等特性成为点击劫持新的利用点。深入分析并实验验证智能手机脆弱特性,在此基础上提出点击劫持在智能手机上的潜在攻击方案。进而设计并实现一套有针对性的检测方案。该方案从静态页面和动态行为两个角度提取攻击特征,并进行基于规则的量化评估与组合判定。实验结果表明该方案可以有效地降低传统页面特征检测方案的漏报和误报情况。     

臭氧氧化法除地表水有机物试验研究

本文阐述臭氧化法除地表水有机物的重要意义，实验结果表明：臭氧氧化有机物的总氧化速率受活化控制，影响氧化率的最高显著因素是温度，其次是ｐＨ，接触时间等，臭氧很容易氧化腐植酸，在３０℃，ｐＨ９．０～１０．０，７ｍｉｎ内，ＣＯＤ去除率可达６０％以上，对邯郸热电厂生产处理也取得良好效果，３５℃，ｐＨ７．４～７．６，１０ｍｉｎ内，ＣＯＤ去除率可达６７％，可望将臭氧化水处理工艺应用于电厂水处理。     

Analysis of deformation processes in glassy polycarbonate using internal friction measurements during a tensile test

Internal friction has been measured by torsion at 1 Hz during tensile tests performed on glassy polycarbonate at room-temperature. Steady-state flow and transient effects have been studied during continuous tensile tests and strain-rate changes. During steady-state, internal friction and flow-stress vary in a similar way with strain-rate. But during transients, internal friction varies continuously while flow-stress passes through a maximum (or a minimum). These results are interpreted assuming that non-elastic deformation of glassy polymers requires some microscopic discontinuous processes such as motion of defects. Two parameters are considered: the velocity v and the density ρ of mobile defects. Assuming that the former is directly related to the flow stress, it has been shown that internal friction is related to the density of mobile defects ρ. This feature is used to interpret the different stages of a tensile test curve. Activation volumes for both velocity and density of mobile defects are calculated from experimental data.     

岩盐溶解速率的研究

在岩盐溶解速率及其影响因素的实验研究基础上,建立了岩盐溶解速率的计算公式。研究的结果可为岩盐开采和其他水溶法矿物开采提供参考。