改性CaTi_(0.9)Li_(0.1)O_3上乙烷催化氧化脱氢制乙烯的研究

ＣａＴｉ０９Ｌｉ０１Ｏ３催化剂中添加ＣｅＯ２、Ｌａ２Ｏ３、Ｙ２Ｏ３、ＮｉＯ等金属氧化物可不同程度地改进催化剂性能,其中以ＮｉＯ／ＣａＴｉ０９Ｌｉ０１Ｏ３催化剂性能最佳,乙烯收率在７７５℃比ＣａＴｉ０９Ｌｉ０１Ｏ３作催化剂提高１２２％,适当控制反应条件,可使７７５℃的乙烷转化率达５５２％,乙烯选择性为７３％。ＮｉＯ／ＣａＴｉ０９Ｌｉ０１Ｏ３催化剂的最佳ＮｉＯ含量为３０％,最佳焙烧温度为８００℃,催化剂上乙烷氧化脱氢适宜的反应条件为,反应温度７７５～８００℃,Ｖ（Ｃ２Ｈ６）／Ｖ（Ｏ２）＝１７～２,原料气空速为（２～３）×１０４ｈ－１,原料气中惰性气体含量为２０％～５０％。     

Solvent-free partial oxidation of cyclohexane to KA oil over hydrotalcite-derived Cu-MgAlO mixed metal oxides

A highly efficient and stable hydrotalcite-derived Cu-MgAlO catalyst was developed for the partial oxidation of cyclohexane with molecular oxygen. The physical-chemical properties of Cu-MgAlO catalysts were studied, and the results indicated that the copper component had been successfully introduced into the hydrotalcite unit layer structure. The catalytic reaction results showed that copper as the active species could activate C-H bond and effectively promote the decomposition of cyclohexyl hydroperoxide (CHHP) to the mixture of cyclohexanol and cyclohexanone (KA oil). 8.3% of cyclohexane conversion and 82.9% of selectivity for KA oil were obtained over 9%Cu-MgAlO catalyst at 150℃ with 0.6 MPa of oxygen pressure for 2 h. Especially, its catalytic performance was still stable after five runs.     

COMPLEX AND REAL PERFORMANCE RADII AND THEIR COMPUTATION

This paper considers the problem of robust performance of a linear time-invariant system in the ℋ︁_∞ norm. The concepts of complex and real performance radii are introduced to describe the smallest size of dynamic or parametric perturbations to a feedback system that either destabilize the system or destroy a performance bound in a certain closed-loop transfer matrix of the system. An algorithm to compute the complex performance radius is given. For the real performance radius, a lower bound, which often turns out to be exact, is obtained. © 1997 by John Wiley & Sons, Ltd.     

Sr复合变质剂对Al-Si合金变质影响的研究（续）

运用正交试验研究Al-10%Sr变质剂对G01铝合金的变质工艺,研究不同的变质剂添加量、变质温度、变质时间对变质效果的影响,探索Sr变质剂在Al-Si合金生产中的工艺方法。     

一种工业无线遥控系统设计

应用MSP430f1232和NRF24L01集成电路设计了一种工业无线遥控系统。介绍了该系统的硬件组成结构和软件实现流程,给出了部分实现程序。经过试验表明,该遥控系统可通过手持端指示灯动态获取接收端工作状态,可以提高工业场合远距离作业时的安全性,适用于单钩、单速电动葫芦或葫芦式桥式起重机。系统结构简单,经过改进也可用于其他设备的控制。     

Back to the Future

Paul Preissner provides a typological prototype for the protocell, the Protocell Tower. Does it, however, already look familiar? Though a breathtaking chemical innovation, could protocell technology actually be behind the curve of architecture? Could it be that architects have already been playing with the aesthetics of this unrealised matter for the last 15 years? Preissner suggests some urban approaches that might enable us to use protocells to rejuvenate existing architecture. Copyright © 2011 John Wiley & Sons, Ltd.     

线能量对A7N01铝合金焊接接头残余应力的影响

焊接残余应力的产生主要是焊接过程中热输入不均匀所造成,因此焊接工艺参数尤其是焊接线能量对焊接接头的残余应力影响较大。通过实际测量与仿真计算相结合的方法,研究线能量的变化对A7N01S-T5铝合金双脉冲MIG焊接头残余应力的影响。结果表明,线能量的增大提高了热输入量,使纵向残余拉应力峰值从149 MPa增加到190 MPa;横向拉应力峰值之间相差不大,但横向拉应力峰值较纵向拉应力峰值高出约27 MPa。仿真计算结果与实测值的应力分布趋势和拉应力的峰值相近,二者之间形成较好的印证关系。     

焊接气孔缺陷对A7N01铝合金焊接接头腐蚀疲劳性能的影响

在不同环境湿度条件下制备了不同焊缝气孔率的A7N01铝合金焊接接头,并通过条件腐蚀疲劳强度和断口微观形貌研究气孔缺陷对焊接接头腐蚀疲劳性能的影响。结果表明,当焊接环境的湿度由常湿增至70%时,焊缝的平均气孔率由0.07%增大为0.16%,接头的条件腐蚀疲劳强度由110 MPa降为100 MPa,焊接气孔缺陷对A7N01铝合金焊接接头的腐蚀疲劳性能有明显影响。焊缝中的气孔会造成严重的缺口效应,引起应力集中,导致裂纹在气孔处优先萌生,并在应力和腐蚀介质的共同作用下形成沿晶与脆性疲劳条带的混合断裂形貌。     

不同焊丝对A7N01铝合金焊接接头力学性能的影响

采用ER5356、ER5183和ER5087焊丝对A7N01S-T5铝合金进行MIG焊接,分析接头力学性能。试验结果表明,三种焊丝的接头焊接残余应力大小基本相当;采用ER5183焊丝焊接的接头抗拉强度和断后伸长率最高,且弯曲性能良好,原因是接头内气孔量较少;采用ER5356焊丝焊接的接头焊缝和热影响区的冲击功最高,ER5087焊丝接头焊缝和热影响区冲击功则低得多。综合来看,ER5183焊丝与A7N01S-T5铝合金的匹配性更好。     

915 MHz TE10-TE01模式转换器设计

本文设计了一种可实现矩形波导TE10模式转换为圆波导TE01模式的转换器,用于电子回旋共振(ECR)技术薄膜沉积,使微波功率以特定模式分布在反应腔中与磁场共同作用产生等离子体,并由磁控管输出的微波中心频率为915 MHz。在满足工作带宽要求的基础上尽量提高转换效率,抑制噪声模式。通过三维仿真软件HFSS对结构进行优化,在915 MHz中心频率处转换效率达到99.90%,在中心频率20MHz范围内转换效率达到99.00%,能够满足磁控管工作频率在915 MHz下的带宽要求。