中央空调管道清洗机器人控制系统设计

为解决中央空调管道清洗难及管径不规范等问题,将自动定心技术应用到管道清洗机器人中,开展了中央空调管道清洗机器人控制系统方案分析与设计。采用模块化的设计思想,以ATmega64单片机为控制核心,建立了各个功能模块之间的关系,实现了中央空调管道清洗机器人整个控制系统的方案设计。在现有的中央空调管道清洗技术基础上,对相关研究成果进行了对比分析及评价。研究结果表明,所设计的清洗机器人能够实现自动定心以适应不同的空调管径,完成清洗作业,为中央空调管道清洗技术提供了广阔的应用前景。     

QAM接收机的定时误差估计算法的研究

定时恢复是全数字接收机中的一项关键技术。以Gardner定时误差检测算法为基础,从理论上对算法的计算复杂度、以及整个定时恢复环路实现的难易程度对其进行分析。以64QAM为例对整个环路进行了仿真验证,该算法对载波相位不敏感,并且简单易行,适用于QAM信号的定时恢复。     

基于64K通道的继电保护缺陷分析与改进

针对2起RCS-931型继电保护64K通道的典型故障现象,进行了详细的分析和研究。分析了电流差动保护装置、PCM和光端机通信设备之间的2M、64K通道配合关系,并结合纵联电流差动保护工作原理,在现场通道试验基础上,阐明了通道故障产生的原因,64K保护用通道存在的缺陷,提出了行之有效解决方案和整改措施,为使用64K通道的...     

基于ATmega64L的128点实时FFT

利用ATmega64L单片机的大容量flash存储器和高速数据处理能力,研究了按时间抽取基2FFT算法在ATmega64L单片机中的实现方法,实现了以ATmega64L为核心的手持式振动信号采集器128点浮点格式采样数据的嵌入式实时快速傅里叶变换。验证了该方法对采样数据进行精确有效的快速傅里叶变换(FFT)分析的有效性和准确性,从而实现对设备运行状态及故障的初步诊断。     

Multilayer additive manufacturing of catalyst-coated membranes for polymer electrolyte membrane fuel cells by inkjet printing

Inkjet printing is a versatile, contactless and accurate material deposition technology. The present work is focused on developing innovative strategies for inkjet printing of Catalyst-Coated Membranes (CCM) by performing Additive Manufacturing (AM) applied to Polymer Electrolyte Membrane Fuel Cells (PEMFC), without resorting to intermediate substrates. Three different approaches for AM are presented and discussed: a) inkjet-printing of the membrane ionomer layer and the top catalyst layer; b) inkjet-printing of both catalyst layers onto a membrane; c) inkjet-printing of the ionomer layer as well as the catalyst layers onto the reinforcement layer of the membrane. The produced catalyst and membrane layers were characterized and proved uniform in terms of catalyst loading (0.2–0.4 and 0.08 mg_Pt cm^?2 for cathode and anode, respectively), ionomer distribution and thickness homogeneity (4 μm for catalyst layers). The fully inkjet-printed CCM outperformed conventionally made assemblies in electrochemical-performance testing, even reaching 15% higher power density.     

Efficient recovery of nano-sized iron oxide particles from synthetic acid-mine drainage (AMD) water using fuel cell technologies

Acid mine drainage (AMD) is an important contributor to surface water pollution due to the release of acid and metals. Fe(II) in AMD reacts with dissolved oxygen to produce iron oxide precipitates, resulting in further acidification, discoloration of stream beds, and sludge deposits in receiving waters. It has recently been shown that new fuel cell technologies, based on microbial fuel cells, can be used to treat AMD and generate electricity. Here we show that this approach can also be used as a technique to generate spherical nano-particles of iron oxide that, upon drying, are transformed to goethite (α-FeOOH). This approach therefore provides a relatively straightforward way to generate a product that has commercial value. Particle diameters ranged from 120 to 700 nm, with sizes that could be controlled by varying the conditions in the fuel cell, especially current density (0.04-0.12 mA/cm²), pH (4-7.5), and initial Fe(II) concentration (50-1000 mg/L). The most efficient production of goethite and power occurred with pH = 6.3 and Fe(II) concentrations above 200 mg/L. These results show that fuel cell technologies can not only be used for simultaneous AMD treatment and power generation, but that they can generate useful products such as iron oxide particles having sizes appropriate for used as pigments and other applications.     

基于Atmeg64矿用电机定子绝缘保护装置设计

电机启停过程中定子绕组温度快速变化对电机绝缘性能会造成不利影响,为克服此现象,介绍一种适用于煤矿井下环境的电机定子绕组绝缘温度控制装置,该装置利用Atmeg64单片机做为主控芯片,用温度传感器检测电机自身温度和环境温度,与设计模型曲线比较,通过其变化控制加热器工作状态,使得电机温度调整到一个相对合理的水平以达到保护定子绝缘、提高电机运行寿命、减少维修、提高效率的目的。     

基于RFC2544协议的网络设备测试仪研究

设计并实现了一种基于RFC2544协议的网络设备测试仪,首先讨论了网络互联设备测试标准RFC2544协议的4种测试标准(吞吐量、延迟、丢失率、背靠背)以及硬件开发平台Tile64卡块的结构和工作原理,然后论述了网络设备设备测试仪的设计架构,以及在Tile64芯片上进行系统方案的实现过程。实验测试结果表明,该设备可以高效的完成网络设备测试功能,且性能上可以进一步提升。     

基于SOCKS的IPv4向IPv6过渡技术

SOCKS协议是可用的功能最强大、应用最灵活、安全性较高的代理协议。基于SOCKS的IPv4向IPv16过渡技术已经成为一种不错的选择。首先讨论了直接在双栈主机上实现IPv4和IPv6的地址转换的BLA技术，然后讨论了通过一个双栈网关来进行IPv4和IPv6的地址转换的SOCKS64技术，最后对这两种技术进行了分析比较。     

Selectively leaching Cu(Ⅱ）and Ni(Ⅱ) from acid mine drainage sludge by using ethylenediamine-ammonium sulfate

A method based on controlling the complexation-precipitation equilibrium of metal ions was proposed to selectively recover nickel and copper from hydroxide sludge formed by lime neutralization of acid mine drainage (AMD),Ethylenediamine(EDA) and ammonium sulfate were chosen as com,plex reagent and precipitating reagent,respectively,to dissolve target metal hydroxides from sludge and limit useless metal ions in the pregnant solution.Results from both synthetic and natural samples show the excellent selectivity for the target metals(copper and nickel) against Fe(Ⅲ）,Ca(Ⅱ) and Mg(Ⅱ）,99% recovery of Cu(Ⅱ） and Ni(Ⅱ）and shorter leaching time can be reached by this process,and the resultant solution can be used for direct electrowinning.The optimum operating conditions are:pH=9-11,ρ(EDA)=40g/L,ammonium sulfate 50g/L,leaching time 5h(for natural sample) and 2.5h(for synthetic sludge),liquid to solid ratio being 4 with mechanical stirring at room temperature.