Rapid synthesis of La0.7Sr0.3MnO3+λ catalysts by microwave irradiation process

Microwave irradiation processing (MIP) was considered as a potential method to synthesize perovskite-type oxides rapidly, cleanly and energy-efficiently. In this paper, La_0.7Sr_0.3MnO_3+λ, a kind of promising catalyst for automobile exhaust purification, was successfully prepared by MIP in not more than 5 min. The sol–gel method was also used for comparison. All the samples were evaluated by catalytic activity tests in the simulated exhaust and characterized by XRD, BET, TEM and XRF analyses. The results showed that the integrated perovskite-type phase and uniform particle size were obtained in the microwave-treated samples. And those ones exhibited a better oxidation activity under slightly oxygen-rich condition than that by sol–gel method, which may be related to more A-site cation vacancies and larger bulk oxygen content generated in MIP. Possible formation mechanism of perovskites in MIP was also discussed.     

大碎石柔性基层沥青性能分析

用沥青大碎石柔性基层对旧路面进行补强，可以有效地提高路面的使用性能，减少反射裂缝的产生，延长道路的使用寿命。对沥青大碎石柔性基层用加德士AH-70、SBS改性沥青和MAC改性沥青分别进行试验，通过试验结果和经济性能对比分析，找到适合此结构的最佳沥青。     

基于类库思想的Powerbuilder录入界面实现

在ERP及其他数据库开发项目中．方便而操作风格一致的录入界面是被用户所广泛要求的。笔者在工程项目中总结了部分用户需要的功能．并在PowerBuilder中以基类的形式实现．在加快工程进度和方便用户方面取得了不错的效果。     

70推土机主离合器分离杆螺栓失效分析

主离合器分离杆螺栓是一个重要安全件，使用中经常发生断裂。经过失效分析确定断裂原因是由其配件引起。提高配件的冷加工质量及改进结构，可解决分离杆螺栓的断裂问题。     

组态软件在应用中的功能扩展

在DDE动态数据交换基础上,采用本地以太网UDP用户数据报协议,解决了组态王不支持网络变量从本机输出的问题,完善了系统功能。     

具有厚大断面的大型球墨铸铁铸件的生产

首先通过电炉—LF精炼炉—VD精炼炉—包内球化的工艺路线获得了足够的优质铁液,然后通过选取合适的分型面、设置合理的浇注系统、设计专用的冷铁、安放足够大的保温冒口和上表面加大加工余量来去除夹渣等措施,成功生产了具有厚大断面的大型球墨铸铁铸件。     

美国的灭火与救援机器人研发综述

设想某一个城镇生产木材调色板的流水线车间里 ,由于电器原因引发了一场火灾 ,致使建筑物坍塌。没有人能够确切地说出有多少工人被埋压在里面 ,更糟的是 ,当毗邻墙体坍塌时 ,隔壁的旧轮胎储藏室也被埋压在下面。于是市消防局派遣一批机器人去现场救援。第一个到达的机器人进入现场调查情况 ,该机器人能忍耐80 0℃的高温炙烤 ,身上安装了摄像机 ,可以给 90 m外的控制室发送图片 ,控制室的指挥人员就可以根据图片决定是否派消防队员冒险进入现场。第二个机器人是无人驾驶卡车 ,进入后便从 75 m远的地方以2 6 gal/ s的速度往火场喷水 ,并用它所…     

CAE在家用电器开发设计中的应用

本文论述了CAE技术及其在家用电器开发中应用流程,并介绍了CAE技术在家用电器开发中的应用及开发实例。最后提出了CAE在实际分析应用中应注意的问题。     

A full-duplex radio-over-fiber system based on optical carrier suppression and reuse

We have experimentally demonstrated a full-duplex radio-over-fiber system using a single light source at central station (CS). Optical carrier suppression modulation scheme was employed to generate 40-GHz optical millimeter wave and up-convert the baseband signal simultaneously at CS for downlink transmission while the same optical carrier was reused at base station for uplink connection. The bidirectional full-duplex 2.5-Gb/s data was successfully transmitted over 40-km standard single-mode fiber (SMF-28) for both upstream and downstream channels with less than 2-dB power penalty. This system shows simple cost-efficient configuration and good performance over long-distance delivery.     

高帧速摄像器

本文介绍了高帧速摄像器的设计、制造、工作和性能。该高帧速有３６０×３６０像素、摄像速度高达５×１０５帧／秒，该摄像器读出电路类似于帧转移ＣＣＤ，由四部分组成