Visualization and modeling for water atomization of low melting point alloy

Liquid metal fragmentation by impinging fast water spray, so called water atomization, is widely used to produce metal powders efficiently. In the present paper, we conduct the high-speed visualization experiments and theoretical modeling for elucidating the mechanism of fragmentation and solidification processes, which are essentially important to control the metal powder characters. We successfully visualize the detailed sequential events from the water spray ejection, freely dropped molten metal of 42Sn-58Bi, followed by their collision, metal fragmentation in liquid phase, and solidification, leading to revealing the fragmentation processes as the impact of water spray and the vapor explosion. Quantified metal particle size convinces that the water atomization simultaneously proceeds fragmentation of metal in liquid phase with solidification. The experimental results of size distribution and mean diameter well validate the proposed physically-consistent theoretical modeling for the prediction of particle size.     

Nanostructural evolution in mesoporous networks using in situ High-Speed Temperature Scanner

Mesoporous networks with a special distribution of functional centers are an important class of high performance materials for catalysts, bioscaffolds, energy conversion and storage systems. Methods of fabrication allowing to control over special distribution of the functional sites of required phases and designed morphology are still of a great challenge. Here, we report a wet-combustion method for functionalization of the mesoporous network of alumina nanofibers with a single fiber diameter of 7?±?2?nm by Ni-based nanoparticles. The second-scale duration of the combustion process developing high flame temperature (>1000?°C) allows fabrication of mesoporous functional networks with tailored size, morphology and homogeneity of the dopants in a single-stage. The mechanism of the combustion process are studied by in situ high-speed temperature scanner, which continuously records the temperature history and applied power during the process. It readily allows quenching of the samples at a specified point, demonstrates the critical effect of a fuel on the decomposition temperature, combustion enthalpy, functional group, and pH. As a result of the wet-combustion synthesis, aligned double core-shell NiO-NiAl₂O₄-Al₂O₃ fibers or NiO nanoparticles deposited onto alumina nanofibers can be formed.     

8051系列单片机的升级产品-DS87C550

介绍带A/D转换和PWM功能的高速微处理器DS87C550     

高速网络处理器IP2022及其在RFID系统中的应用

IP2022是一款高速网络微处理器,可以方便地实现以太网通讯,本文介绍了IP2022系列的整体结构和功能,及其在以太网数据传输,高速数据采集,编解码方面的优点和特性。并举例说明了此型号处理器在射频设备系统中的应用和注意事项,可供工程研发人员参考。     

高速网络处理器IP2022及其在RFID系统中的应用

IP2022是一款高速网络微处理器，可以方便地实现以太网通讯，本文介绍了IP2022系列的整体结构和功能，及其在以太网数据传输，高速数据采集，编解码方面的优点和特性。并举例说明了此型号处理器在射频设备系统中的应用和注意事项，可供工程研发人员参考。     

高速切削刀具材料的进展和未来

文章结合高速切削技术和刀具材料的研究,综述了高速切削刀具材料的进展和应用,阐明了我国高速切削刀具材料面临的机遇和挑战,指出了高速切削刀具材料的未来。     

高速高效加工中心的新型结构

对高速高效加工中心进行了研究,提出工件固定、以直线电机组成并联链直接驱动刀具作多自由度运动,并实现高速高精度传动与高刚度支撑合二为一的新型结构。开发全闭环交流永磁同步直线电机进给系统,设计高可靠性换刀系统和敏捷化托盘交换系统。     

高速PCB信号完整性设计及制造简述

随着信息高速化的发展,PCB信号完整性设计及制造变得越来越重要。PcB信号完整性问题主要由信号反射、串扰、地弹、电源反弹等引起,文章在理论上简要的一一介绍了它们,这对建立信号完整性的全面知识结构很有帮助。接着对常见的信号完整性设计进行了分析,并指出仿真以成为信号完整性设计必然选择。最后文章对实际生产制造时,需要注意的关键控制点进行了说明。     

基于MB9BF50X且具有高速计数功能的PLC可行性设计

该文提出了一种基于MB9BF50X的可编程逻辑控制器（简称PLC）的设计思路,重点对32位高速脉冲计数器的实现做了详细分析和验证。通过利用富士通公司（简称FUJITSU）的FM3 EasyKits开发板,进行高速脉冲计数的实验,验证能否实现高达200kHz左右的高速脉冲计数。     

降低梧州地区WCDMA网高铁线路覆盖建设和维护成本的探讨

根据梧州地区高铁沿线环境现状,结合南广高铁WCDMA专网规划,通过对传统的配套建设方案和电源集中拉远方案对比分析,阐明了使用电源集中拉远方案作为南广高铁梧州段配套建设方案,不但节省建设投资而且节省后期维护成本.