基于GPRS的输油管道阴极保护远程监测系统设计

为实现输油管道阴极保护系统的远程自动化监测与参数集中管理,开发了一种基于GPRS的分布式管道阴极保护参数远程监测系统;设计监测终端检测现场保护点的阴极电位、恒电位仪电压和阴极保护电流,采用GPRS无线网络以TCP/IP方式远传数据至监测中心工控机,实现了分布式多监测点阴极保护状态的在线监测与参数管理;运行测试结果表明,该系统稳定可靠,实现了对多站点、多通道数据的远程集中监测,阴极电位的检测精度达到了0.5%,可满足输油管线阴极保护的远程自动化监测需求。     

时基反馈控制的Tesla变压器初级电源

LC谐振充电是Tesla变压器常用的初级电容充电技术,但存在对控制时序要求高、易受电磁干扰和不具备故障保护能力等缺陷。针对这个问题,提出了一种时基反馈控制的LC谐振充电电源。该电源与传统LC谐振电源的主要区别在于,采用特殊设计的时基反馈电路取代多路时基控制器,将能量回收开关反向阻断瞬间的电压突变调制为谐振晶闸管触发信号,从而在能量回收结束时刻启动谐振充电,实现各工作回路准确按照预定时序运行。时基反馈电路由高压元件构成,不易受电磁干扰,且在原理上具备负载短路保护能力。该技术已经应用于CKP1000,CKP5000等多台Tesla型超宽谱脉冲源。实验结果表明,在强脉冲辐射环境下,该电源能够1000 Hz重频稳定运行,且能够在Tesla变压器初级短路故障时进行快速自动保护。     

原子构成万物是宇宙结构的美 ——原子随笔之二

人类很早就在寻找宇宙万物的组成.古希腊最早的唯物论派从物质世界的内部寻找宇宙万物的本源,认为宇宙万物都由"种子"组成.德谟克利特在这种"种子"思想基础上,提出了宇宙万物是由原子组成的猜想.     

Mechanism transition of self-pumped phase conjugation in KTa1 −xNbxO3:Fe crystals

Mechanism transitions of Self-Pumped Phase Conjugation (SPPC) with wavelength and doping concentration are observed in KTN:Fe (KTa_{1 –x} Nb _x O₃:Fe with _x = 0.48) crystals. The SPPC mechanism in KTN: Fe (0.4 wt. %) crystal transforms from Stimulated Photorefractive Backscattering and Four-Wave Mixing (SPB-FWM) to cat (or total internal reflection) as the wavelength increases from 514.5 nm to 620 nm. SPPC at 514.5 nm is formed with the cat mechanism in a 0.2 wt. % doped KTN:Fe crystal, while with the SPB-FWM mechanism in a 0.4 wt. % doped one. These mechanism transitions are discussed with respect to the dependence of the backscattering gain coefficient of the crystals on wavelength and doping concentration.     

闪光辐射照相及光学高速摄影图象的增强处理

本文介绍图象增强处理技术在闪光辐射照相图象及光学高速摄影图象中的应用.针对闪光图象及高速摄影图象的特点,研究了一些有效的图象增强方法,取得了很好的应用效果. 文中给出了部分应用实例.     

The tribology properties of alumina/silica composite nanoparticles as lubricant additives

The as-prepared alumina/silica (Al₂O₃/SiO₂) composite nanoparticles were synthesized with a hydrothermal method and modified by silane coupling agent. The tribological properties of the modified Al₂O₃/SiO₂ composite nanoparticles as lubricating oil additives were investigated by four-ball and thrust-ring tests in terms of wear scar diameter, friction coefficient, and the morphology of thrust-ring. It is found that their anti-wear and anti-friction performances are better than those of pure Al₂O₃ or SiO₂ nanoparticles. When the optimized concentration of nanoparticle additive is 0.5 wt.%, the diameters of wear scar and friction coefficients are both smallest. Such modified composite nanoparticles can adsorb onto the friction surfaces, which results in rolling friction. Therefore, the friction coefficient is reduced.     

基于神经网络的闪光照相网栅图像修补

提出了一种基于径向基函数（RBF）神经网络的闪光照相网栅图像修补算法,该方法采用滑动窗口方法将待修补的网栅图像分为若干子块,然后在每个子图像内分别引入RBF神经网络,将栅孔内图像作为已知数据计算RBF网络参数,并以此对每个子图像进行修补,数值试验表明,该算法能较好地再现图像边缘信息,修复的图像在信噪比和视觉方面都优于线性插值和样条插值的结果。     

基于热传导原理电枢平均磨损率计算

在假设导轨为半无限长固体导体及电枢表面磨损主要是熔化磨损条件下,基于固体接触面导热原理,推导出电枢和导轨温度分布方程,提出了电枢平均磨损率计算方法。利用此方法分析了驱动电流、电枢和导轨材料匹配和接触面积参数对电枢平均磨损率影响。将平均磨损率计算结果与Stefani和Parker的实验结果进行对比,二者吻合较好,从而为建立电磁轨道炮磨损率与转捩之间的关系提供理论支持。     

Consensus protocol for heterogeneous multi-agent systems: A Markov chain approach

This paper deals with the consensus problem for heterogeneous multi-agent systems. Different from most existing consensus protocols, we consider the consensus seeking of two types of agents, namely, active agents and passive agents. The objective is to directly control the active agents such that the states of all the agents would achieve consensus. In order to obtain a computational approach, we subtly introduce an appropriate Markov chain to cast the heterogeneous systems into a unified framework. Such a framework is helpful for tackling the constraints from passive agents. Furthermore, a sufficient and necessary condition is established to guarantee the consensus in heterogeneous multi-agent systems. Finally, simulation results are provided to verify the theoretical analysis and the effectiveness of the proposed protocol.     

非低温法的稀有气体纯化技术概述

稀有气体广泛应用于工业生产中,如离子刻蚀、检漏等。但是它们在地球上的含量比较少,属于稀有资源,因此需要对它们进行纯化以循环再利用。首先介绍了不同气体纯化的原理,然后以实际生产中的不同稀有气体使用范围为例,说明纯化装置的设计方法和需要考虑的问题。为以后气体纯化装置的设计提供借鉴。