多机器人通信中防冲突方法研究

研究多个机器人通信中的冲突问题。针对当有针对当对机器人同时进行通信的时候,一个机器人可能同时接受多个其它机器人发来的指令,在时域指令信号方面形成冲突,造成机器人之间通信成功率不高的问题。为了解决这个问题,提出冲突自调整多机器人通信方法,算法利用新到达指令填充离开指令造成的空闲时隙,解决时域信号冲突。利用捎带检测技术,提前对下个时隙进行调整,进行空闲时间预留,减少空闲时隙的产生。很好地减少空闲时隙,解决由此带来的通信成功率不高的问题。实验结果表明,这种方法在多个机器人同时通信的情况下,能够很好地协调通信关系,避免指令冲突,提高了多机器人的通信成功率。     

变形镜交连值的优化分析

关于优化光波控制,自适应光学校正是至关重要的一个环节,可用于改善激光光束质量及校正光束在传输过程中气流引起的波前畸变等。变形镜是其核心器件,而交连值是影响变形镜校正精度的关键因素。针对变形镜实际使用时需要对致动器进行一定的约束,利用带约束的最小二乘法,分析了在一定约束条件下交连值变化对变形镜校正精度及控制稳定性的影响。以Zernike像差和以大气湍流模型构造的像差为校正对象,寻找校正效果最好的交连值。结果表明各阶Zernike像差对应的最优交连值差异较大,最优交连值主要分布在15%～35%之间。从控制误差引起的校正效果变化的方面考虑,对正方形致动器排布的最优交连值位于15%～25%区域。     

Changes in seebeck coefficient of Pt and Pt 10% Rh after use to 1700°C in High-purity polycrystalline alumina

A technique is presented that enables the effects of temperature on the Seebeck coefficient to be assessed for individual wires. The technique, involving a high-resolution thermoelectric scanning rig and a nonuniform conditioning furnace of known temperature profile, was applied to 0.5-mm-diameter wires of Pt and Pt 10% Rh. Changes were observed in Seebeck coefficient when these wires were used in high-purity twin-bore insulation for up to 200 h at temperatures over the range 500 to 1700°C. Contamination from the insulation was found to be transmitted by a vaporization process, having an activation energy of 3 eV. This caused changes of up to 0.14 V · °C^–1 in Pt and 0.01 V · °C^–1 in Pt 10% Rh. Rhodium transfer to the pure Pt wire changed its Seebeck coefficient by up to 5 V · °C^–1. The consequences of both processes for thermocouple pyrometry are presented.     

Thermal accommodation coefficient of gases on controlled solid surfaces: Argon-tungsten system

The knowledge of the thermal accommodation coefficient for gases on well-controlled surfaces as a function of temperature is imperative to understanding the mechanism of interphase heat transfer on the microscopic level. With this goal in view, a heat transfer column instrument is designed, fabricated, assembled, and tested for the specific case a argon—tungsten system. With 99.9999%, pure argon, six sets of data are taken in the rarefied gas region in the maximum temperature range of 500–1500 K. Four sets of these measurements are in the temperature-jump region and are analyzed by the constant-power method to compute the thermal accommodation coefficient of argon on a controlled tungsten surface. The other two sets are taken under free-molecular flow conditions and are interpreted in accordance with the man-free-path kinetic theory for the low-pressure regime. These data are compared and discussed in the context of reported data in the literature and interpreted in the light of the surface condition and finish of the tungsten wire.Nomenclature A area of the solid surface - C _j constants in Eq. (3); j=0, 1, 2, 3, and 4 - E _i incident energy flux - E _r reflected energy flux - E _s reflected energy flux when the interaction between the gas and the solid atoms is complete - g temperature-jump distance - L half-length of the metal wire - M molecular weight of the gas - P gas pressure - Q _H total thermal energy conducted by the gas per unit time from the hot surface - Q_KT total thermal energy conducted by the gas per unit time if the striking gas molecules were to attain thermal equilibrium with the hot surface - R molar gas constant - r radial coordinate - r _f radius of the hot wire - S sticking coefficient - S_o initial sticking coefficient - T temperature - T _e linearly extrapolated gas temperature on the hot-wire surface - T _g temperature of the impinging gas molecules - T _H temperature of the hot surface - T _i temperature of the incident gas stream - T _r temperature of the gas molecules receding after collision with the solid surface - T _s temperature of the solid surface Greek Symbols thermal accommodation coefficient for the gas—solid surface - resistivity of the metal wire - gas coverage on the solid surface For an explanation of symbols, see Nomenclature.     

人群头发元素分布及某些特征研究

本文介绍用堆中子活化分析法测定人群头发中I、Br、Mg、Mn、Cu、Na、V、Cl、Al、Ca、S等11种元素。研究人发中元素分布特征、相关性特征、性别年令分布特征。方法学中还从法庭科学应用角度介绍同一性识别中差异率和重合几率的双判据方法。     

Electrochemical investigation of the iron-containing and no iron-containing AB5-type negative electrodes

The electrochemical behaviour of LaNi_3.55Mn_0.4Al_0.3Co_0.75−xFe_x (x = 0, 0.15, 0.55, 0.75) intermetallic compounds has been studied and presented [C. Khaldi, H. Mathlouthi, J. Lamloumi, A. Percheron-Guégan, Int. J. Hydrogen Energy 29 (2004) 307–311; C. Khaldi, H. Mathlouthi, J. Lamloumi, A. Percheron-Guégan, J. Alloys Compd. 360 (2003) 266–271; C. Khaldi, H. Mathlouthi, J. Lamloumi, A. Percheron-Guégan, J. Alloys Compd. 384 (2004) 249–253]. It has been deduced that the LaNi_3.55Mn_0.4Al_0.3Co_0.4Fe_0.35 compound has interesting electrochemical properties. In this paper we present the electrochemical study of LaNi_3.55Mn_0.4Al_0.3Co_0.4Fe_0.35 compound properties compared with the parent LaNi_3.55Mn_0.4Al_0.3Co_0.75 compound. Several techniques, such as, the chronopotentiometry, the constant potential discharge (CPD), the cyclic voltammetry (CV) and the linear polarization (LP) were applied to characterize these electrochemical properties. The electrochemical discharge capacity of the LaNi_3.55Mn_0.4Al_0.3Co_0.75 alloy increases to reach 294 mAh g⁻¹ after few cycles only (five cycles). However, the activation of the LaNi_3.55Mn_0.4Al_0.3Co_0.4Fe_0.35 alloy takes more than 20 cycles to be achieved and the obtained maximum discharge capacity is 194 mAh g⁻¹. The hydrogen diffusion coefficient D_H was determined by constant potential discharge and cyclic voltammetry techniques. The obtained values of the LaNi_3.55Mn_0.4Al_0.3Co_0.75 and LaNi_3.55Mn_0.4Al_0.3Co_0.4Fe_0.35 compounds are 6.29 × 10⁻¹¹ and 7.62 × 10⁻¹¹, and 2 × 10⁻⁸ and 7.5 × 10⁻⁸ cm² s⁻¹ by CPD and CV techniques, respectively. The exchange current density values, determined by a linear polarization technique, are 44 and 27 mA g⁻¹, respectively, for LaNi_3.55Mn_0.4Al_0.3Co_0.75 and LaNi_3.55Mn_0.4Al_0.3Co_0.4Fe_0.35 alloys.     

四辊铝箔轧机预控参数在线整定

介绍Ф210mm/Ф500mm× 800mm四辊液压轧机厚度预控系统中采用人机界面实现参数在线调整的方法,能大大提高预控参数的控制精度,减少轧机产品的厚度误差,是厚度自动控制的一项创新.     

计及互联调控的新能源汽车一体化供能站规划

为了解决插电式电动汽车、换电型电动汽车和氢燃料电池汽车大规模接入背景下的综合能源站规划问题,首先提出一种包含三种主流新能源汽车供能设备的一体化供能站概念模型;其次,提出氢能转运、换电电池转运、服务费调控三种互联调控模型,以增强各站间的联系;然后,以全周期综合费用为优化目标,提出计及互联调控的新能源汽车一体化供能站规划模型;最后,基于IEEE 33节点配电网和某市部分城区交通网的联合系统进行仿真验证。结果表明所提模型优化了设备配置,改善了系统运行状态,延缓了配电网的升级改造。     

Mixed Micelles of Surface Active Ionic Liquid (SAIL)–Octylphenol Ethoxylate: A Novel Reaction Medium for Selective Oxidation of Toluene to Benzaldehyde

Ionic liquids have been found to be suitable alternatives to volatile organic solvents in chemical transformation. Through a proper choice of cations and anions, the properties of an ionic liquid can be tuned so that it resembles an amphiphile. Such specially designed molecules are known as surface-active ionic liquids (SAIL). Like conventional surfactants, SAIL also form aggregates in an aqueous medium. Studies show that the mixing of SAIL with conventional surfactants leads to synergistic micellization. However, very few reports are available on the application of such systems as reaction media. Present study focuses on the application of mixed micelles of 1-tetradecyl-3-methylimidazol-1-ium bromide, ([C₁₄mim]Br) with nonionic surfactant, Octylphenol ethoxylate with 10 moles of ethylene oxide (OPE-10). Enhanced solubilization and selective catalytic oxidation of toluene using hydrogen peroxide as an oxidant and tungstic acid as a catalyst have been studied in detail using this system.     

Design of a low temperature coefficient bandgap reference with a wide temperature range

In order to meet the requirements of different applications and markets for the accuracy and reliability of IoT chips,a low temperature coefficient bandgap reference with a wide temperature range is proposed.On the basis of the traditional Banba bandgap reference structure,the circuit utilizes high-order temperature compensation technology and piecewise temperature compensation technology to improve the curvature of the output reference voltage.The temperature coefficient of the circuit is reduced.At the same time,the operating temperature range of the circuit is extended.The circuit performances are verified in the TSMC 180 nm CMOS process.Test results show that the temperature coefficient of the circuit is as low as 7.2×10^-6/℃ in the range of-40 ℃ to 160 ℃.The power supply rejection ratio at a low frequency is -48.52 dB.The static current under the 1.8 V power supply voltage is 68.38 μA,and the core area of the chip is 0.025 mm².