Reaction between Lanthanum and Phosphorus in Steel

P always causes low temperature emhrittlement and temper embrittlement owing to itsgrain boundary segregation[']. Garcia C I etal. [2) reported a complex compound containingLa, O I S and P, in which LaZOZS acted as anucleation site and Fe-P precipitated on thesurface of the oxysulfide. Nevertheless, thermodynamic calculation by Seah M P showedthat La could not react with P in steel unlesstemperature is lower than 1100 T, sinceGibbs free energy of formation of LaP is positive above thi…     

Excel在企业工时定额工作中的应用

将Excel引入企业工时定额管理进行数据分析.     

Y/Eu co-doped TiO2:synthesis and photocatalytic activities under UV-light

Y and Eu co-doped nano-TiO2 photocatalysts were successfully prepared via a sol-gel method and characterized by X-ray diffraction(XRD), transmission electron microscopy(TEM), ultraviolet-visible spectrophotometry(UV-vis), photoluminescence(PL) and Fourier transform infrared(FT-IR) spectra. Experimental results indicated that Y and Eu doping inhibited the growth of crystalline size and the transformation from anatase to rutile phase and had the function of reducing particle reunion. At the same time, co-doping could also enhance the absorption in visible region and then narrowed the band gap. The photocatalytic activities of the samples were evaluated by the degradation of methylene blue(MB) under ultraviolet(UV) light irradiation, which showed much enhanced photocatalytic activities over un-doped TiO2. The degradation rate of 1.5% Y/Eu-TiO2 of methylene blue was 86%, which was about 5 times of that of un-doped TiO2, and the possible reasons for the improvement of photocatalytic activities were analyzed. In this experiment, the dopant amount of rare earth was 1.5% and the ratio of Y:Eu was 2:3 for the maximum photocatalytic degradation, and the sample calcined at 500 oC showed the best reactivity. For the best samples above, the removal rate of phenol under visble light was 53% whthin 2 h.     

SiO2-Al2O3-CaO-MgO系夹杂物低熔点区域优化及控制的热力学计算

为了预测CaO-Al2O3-SiO2-MgO系夹杂物具有良好变形能力的成分控制范围,首次通过热力学软件Fact-Sage对CaO-Al2O3-SiO2-MgO系液相投影图、低熔点区域大小进行了计算分析,并以阀门弹簧钢60Si2CrA为例,对CaO-Al2O3-SiO2-MgO系低熔点夹杂物的生成条件进行了探讨.结果表明...     

基于单片机的红外测温仪设计

设计以单片机作为整个测温仪的核心,结合A/D转换器、液晶显示器等外部设备,在软件设计和硬件设计的基础上,设计出一种拥有汉字显示逻辑判断等智能型电子测温计。它提供了一种新的温度测量方案,采用红外温度传感器来测量温度信号,可同时测量目标温度和环境温度,并将测量的数据经过放大器,转换器送给单片机处理,之后送数码管显示。红外测温打破了传统的测温模式,它响应快、测量精度高、可靠性高、范围广,为非接触测量,因而不易损坏。该温度计以准确快捷的测量功能、清晰易懂的数字化显示方便人们日常生活使用。     

ZigBee无线传输技术综述

ZigBee技术是一种新兴的短距离、低复杂度、低功耗、低数据速率、低成本的无线网络技术。ZigBee协议采用IEEE802.15.4标准的物理层和链路层,并在其上增加了网络层,安全模块和应用支持子层模块,从而实现了大区域网络覆盖。ZigBee由于其在低功耗、低复杂度、自组织等方面的优势,逐渐成为无线传感器网络的首选通信协议。     

火灾烟雾报警系统的设计

主要对火灾报警控制器的理论做了深入的研究,使用单片机,选用烟雾传感器、红外传感器等多个传感器作为敏感元件,结合信息融合技术,全面阐述了研制火灾报警控制器硬件部分和软件部分的方法。采用protel99绘制电路图并进行电路仿真,证明整个系统电路设计合理,性能安全可靠。     

基于ARM处理器的CAN节点设计

引言随着信息技术的飞速发展,基于ARM在嵌入式系统方面的优势和CAN总线的广泛应用,目前越来越多的ARM处理器内部自带了CAN控制器,极大的方便了开发人员对CAN总线的开发。本课题是基于ARM2104的微处理器CAN总线系统节点开发,采用CAN总线可以将节点控制器直接     

提高液体二氧化硫品质的有效措施——终端过滤器

如何提高液体二氧化硫产品品质是生产厂家都遇到过的问题,根据主要影响因素,解决方案也各有不同。随着无油润滑压缩机的使用,产品含油发黄的问题可以得到解决。现在主要问题是机械杂质和水分的影响,尤其是新系统生产之初多遇到此情况。     

热镀锌锅过早开裂失效的原因诊断

镀锌锅的过早腐蚀和失效开裂 ,导致镀锌成本的上升和生产的极大损失。针对某单位的锌锅在投入使用时 ,即产生开裂失效的现象 ,通过对锌锅原始断口形貌和金相组织 ,X荧光光谱全成分分析、拉伸力学性能和拉伸断口形貌及锌锅受力情况的数值模拟等的研究结果表明 :锌锅钢板中存在的沿晶渗碳体是锌锅过早开裂失效的重要原因