基于似人特性的机器人拟人臂自主抓取动作规划

针对拟型服务机器人在家庭环境中的自主抓取任务,提出了一种强调运动姿态似人特性的机器人手臂动作的运动规划方法.该方法基于人体工程学中的快速上肢评估准则评价机器人运动姿态的似人特性,并在此基础上以机器人传速速率最优为目标规划机器人持物动作的姿态构型.最后以Motoman SDA10D拟人双臂机器人为例,具体介绍了该方法的应用和规划的结果,规划结果证明了该方法的可行性和有效性.     

Drag of nonspherical particles in a flow behind a shock wave

The early stage of velocity relaxation of nonspherical particles in a flow behind an incident shock wave is considered by the method of multiframe shadowgraphy. A procedure of processing the data on the motion of a free body for determining its acceleration is proposed; in combination with the diagnostic method used, the procedure forms something like a noncontact aerodynamic balance. Novel data on the drag of bodies of irregular shape in a flow behind a shock wave with Mach numbers of 0.5–1.5 and Reynolds numbers of 10⁵ typical of dust explosions are obtained. It is found that the values of drag of a nonspherical bluff body and a sphere under these conditions are similar and exceed the drag of a sphere in a steady flow by a factor of 2 to 3.Translated from Fizika Goreniya i Vzryva, Vol. 41, No. 1, pp. 81–88, January–February, 2005.     

A型地铁空调系统及客室内流场数值分析

为给目前国内A型地铁车辆的舒适度设计提供理论参考,针对地铁车辆静压风道结构特点,基于k-ε两方程湍流模型和SIMPLE算法,建立包含空调送风风道和客室的三维计算模型.对计算模型的空气流动和传热状况进行CFD数值计算.计算过程综合考虑车体壁面传热和人体散热等多种传热.分析计算结果得到客室内温度场和速度场的分布规律,并对空调通风设计方案进行量化评估.计算结果表明:客室内人体头部区域温度场分布均匀,平均温度为26.6℃,最大温差为6℃;车厢内有较理想的气流组织形式,速度分布范围为0.50~0.79 m/s,而且客室端部和中部区域人体头部周围速度较大.将计算结果与欧洲EN 14750-1标准进行对比分析,认为乘客的舒适性较好.     

在文明寨地区的高精度地震资料处理实践

文明寨地区构造复杂，断块多，岩性变化大，一些地质问题不明，需要高精度三维资料处理来提高资料的纵、横向分辨率^[1][2]及为储层、油藏研究提供精确的依据。针对东濮文明寨地区高精度处理过程中的关键技术进行了大量分析试验，形成了一套适合东濮地区的较为完整的3D高精度地震资料处理流程。实际资料处理表明效果较好。     

Release rates of tetradecen-1-ol acetates from polymeric formulations in relation to temperature and air velocity

An apparatus was developed for investigating the release rates of pheromone formulations at temperatures and air velocities that correspond with those in the field. Polyurethane foam proved an excellent adsorbent for the recovery of tetradecen-1-ol acetates, allowing high air flows at low differential pressure and without breakthrough of these compounds. The experimental setup and procedures are described. The release rates of all formulations investigated were almost proportional to the square root of air velocity, and their logarithms were proportional to the reciprocal of temperature (K). When temperature is increased from 15°C to 25°C, the release rates increase by about 2-2.5 ×. Both relationships were combined into one equation that allows a reliable estimate to be made of the actual release rates of a formulation, under varying conditions, on the basis of its specific parameters and the relevant meteorological data.     

Liquid spouting of pulp fibers in a conical vessel

Pulp fibers can be spouted in water in a conical vessel. The entities which are spouted are fiber flocs rather than individual fibers. Synthetic fibers, which do not flocculate, cannot be spouted. For comparison, rigid spherical particles were spouted with water in the same conical vessel. Liquid spouting of rigid particles was similar to gaseous spouting. For pulp spouting, the minimum spouting velocity is proportional to the mass of fibers in the bed and inversely proportional to the diameter of the inlet. For rigid particles, the minimum spouting velocity is proportional to the height of the bed and inversely proportional to the square of the diameter of the inlet. A model for the minimum spouting velocity was developed for pulp spouting.     

Finite-time consensus of multiple second-order dynamic agents without velocity measurements

This article considers the finite-time consensus of multiple second-order dynamic agents without velocity measurements. A feasible protocol under which each agent can only obtain the measurements of its position relative to its neighbours is proposed. By applying the graph theory, Lyapunov theory and the homogeneous domination method, some sufficient conditions for finite-time consensus of second-order multi-agent systems are established under the different kinds of communication topologies. Some examples are presented to illustrate the effectiveness of the theoretical results.     

用激光技术测定液体中的声速和等熵压缩性系数

本文应用根据激光光声原理和技术建立的流体热力学性质测量实验装置，测定了七个温度下苯、四氯化碳液体中，苯与四氯化碳二元溶液中的声速（ｕ）、密度（ρ），计算了等熵压缩性系数（Ｋ＿ｓ）等热力学数据。用多项幂级数，以最小二乘法拟合声速ｕ与温度ｔ的数学关系。实测的声速值与文献值比较，相对误差小于０．０４％，等熵压缩性系数与文献数据也相当吻合。     

Molar volume and ultrasonic studies of europium soaps in mixed organic solvents

The ultrasonic velocity and density measurements of europium soaps in a mixture of benzene and methanol (3:2, vol/vol) were used to evaluate various acoustic parameters and molar volume and to determine the critical micelle concentration. The results showed that the ultrasonic velocity, specific acoustic impedance, molar sound velocity, and molar compressibility increase, and intermolecular free length, adiabatic Compressibility, and relative association decrease with increasing concentration and chainlength of the soap. The results were interpreted in terms of soap-solvent interaction.     

Propagation of the Chain Explosive‐Decomposition Reaction in Silver Azide Crystals

The velocity of the chain explosivedecomposition reaction in silver azide whiskes has been measured (1500 m/sec). The measured velocity is identified as the propagation velocity of the diffusion front of holes generated in the course of explosive decomposition.