Preparation of mullite whiskers and their enhancement effect on ceramic matrix composites

Mullite whiskers were facilely prepared by sintering kyanite at high temperature, with the addition of AlF3·3H2O. The as-prepared whiskers have been characterized systematically in terms of phase composition, morphology, and structure. Results showed that the morphology and size of mullite whiskers were strongly depended on the content of AlF3·3H2O and sintering temperature. At temperatures in the range of 1 100 to 1 500 ℃ with 4 wt% addition of AlF3·3H2O, the well-shaped mullite whiskers were obtained. For an instance, the mullite whiskers with 5-10 μm in length and 0.1-0.2 μm in cross-section could be formed at 1 400 ℃, with 4 wt% addition of AlF3·3H2O. Moreover, results showed that the addition of mullite whiskers into ceramic matrix enhanced its fracture toughness significantly.     

大型磷酸萃取槽的防腐施工

提出大型砼基磷酸萃取槽内部防腐的一种新型式——采用预硫化丁基胶板作防渗层,以酚醛胶泥砌筑粗颗粒高灰分非浸渍碳砖作防磨层的防腐方案,介绍了预硫化丁基胶、粗颗粒高灰分非浸渍碳砖、酚醛胶泥的性能,总结了相关的施工方法和经验。     

热化学硫碘制氢中碘化氢催化分解的实验研究

采用溶胶-凝胶技术,将Pt掺杂进入Ce0.50Zr0.49和Ce0.50Zn0.49基体,制备了1% Pt0.01/Ce0.50Zr0.49和Pt0.01/Ce0.50Zn0.49 2种催化剂,催化剂通过BET、XRD和SEM进行了特性表征,同时通过碘化氢催化分解实验系统对其分解HI的催化性能进行评价.柠檬酸溶胶-凝胶法可以形成较为完整的Ce-Zr固溶体,但没有形成Ce-Zn固溶体,催化剂中的Pt主要以金属态存在.Pt0.01/Ce0.50Zr0.49物质形态相对比较致密,空隙较少,孔径也比较小,Pt0.01/Ce0.50Zn0.49由微米级别的致密晶粒ZnO和尺寸更小结构相对比较疏松的晶粒CeO2共同组成,比表面积和平均孔径更大.在450℃以下,文献[1]中的催化剂表现出更好的催化效果,但随着温度的进一步升高,催化剂Pt0.01/Ce0.50Zr0.49和Pt0.01/Ce0.50Zn0.49表现出更好的效果,在550℃时,HI分解率分别达到了32.9%和33.75%.     

基于恒定姿态误差的磁罗差偏差补偿算法研究

针对具有恒定俯仰角度载体的磁航向罗差标定和补偿问题,提出了一种用于磁罗差修正的偏差补偿算法(DCA)。通过DCA的原理分析和证明得出:该算法对具有恒定横滚角度和俯仰角度的磁航向罗差修正均有效,经过DCA补偿的磁航向角度误差在±0.3°以内,满足飞机的航向标定要求。     

汽车自动变速器示教板的设计

利用单片机控制发光二极管和光纤来模拟汽车自动变速器的油路、阀体及其故障现象，采用键盘和LED显示器进行人机交互，操作方便简单，软件成功地模拟自动变速器的核心技未——自动换档功能，使学生能够清晰地领会自动变速器的工作原理。     

供应链管理的下一步--全球供应链透明化

供应链与物流管理的精神就是最佳化的库存管理——在最低成本与风险之下，有效满足顾客需求，达成企业的目标。     

广东省电能计量遥测系统建设概况

电能计量遥测系统建设对于提高电网经济运行水平具有重要意义,广东省于1999年开始进行计量遥测系统建设,目前已经接近基本完成。本文总结了广东省省公司及地市局关口计量遥测系统的建设概况。     

Soft sensor modeling based on Gaussian processes

1INTRODUCTION Withthedevelopmentoftechnologyandthe complicationofindustrialprocesses,weneedto implementreal timecontroloroptimizationforvariableskeytotheprocessinordertoensurethe safetyandefficiency.However,someimportant variablesaredifficulttobedetectedduetothelim itationofeconomyandtechnology.Traditionally,therearetwoapproachestosolvethisproblem.Thefirstoneiscontrollingtheindustrialprocesswithassociatedqualitycriteria.However,thepre cisionofqualitycriteriacannotbeinsuredinmost situation…     

强化实践教学 注重生产实习环节

本文强调了生产实习重要性,并从实习时间、实习方式、实习基地、指导教师选择等方面着手,谈谈如何加强生产实习环节。