Oxidative coupling of methane over Na+-ZrO2-C1-/Al2O3 catalysts

Oxidative coupling of methane (OCM) was carried out over Na⁺-ZrO₂-Cl /A1[₂O₃ catalysts in a temperature range from 1023 to 1123 K. The catalysts were prepared by impregnating the α- or γ-Al₂O₃ supports with sodium carbonate and/or zirconyl chloride. The OCM activity was examined using the catalysts prepared by three different preparation procedures. The best catalyst was the one prepared by subsequent impregnation of sodium carbonate-preimpregnated γ-Al₂O₃ with a mixed solution of sodium carbonate and zirconyl chloride. It was found that preimpregnated sodium played an important role in reducing the combustion activity of the γ-Al₂O₃. The catalyst with an optimal composition showed the highest C₂ selectivity and yield of 40.8% and 15.1%, respectively. From the X-ray diffraction analysis it was found that tetragonal ZrO₂ was formed and that NaCl existed in the catalysts with relatively high sodium contents.     

Electrodeposition Behaviour of Cadmium Telluride from 1-ethyl-3-methylimidazolium Chloride Tetrafluoroborate Ionic Liquid

Voltammetry at a glassy carbon electrode was used to study the electrochemical deposition of Cd–Te from the Lewis basic 1-ethyl-3-methylimidazolium chloride/tetrafluoroborate air-stable room temperature ionic liquid between 80 °C and 140 °C. Deposition of tellurium alone occurs through a four-electron reduction of Te(iv) to Te which could be further reduced to Te(-ii) at a more negative potential. The Cd–Te electrodeposits could be obtained by the underpotential deposition (UPD) of Cd on the deposited Te. The UPD of Cd on Te was, however, limited by a slow charge transfer rate. Samples of Cd–Te electrodeposits were prepared on tungsten and titanium substrates and characterized by energy dispersive spectroscope (EDS), scanning electron microscope (SEM), and X-ray powder diffraction (XRD). The results showed that an excess amount of Cd(ii) was required in order to prepare CdTe codeposits with a Cd/Te atomic ratio approached 1/1. The deposit composition was independent of the deposition potential within the Cd UPD range. Raising the deposition temperature increased the UPD rate of Cd and promoted the formation polycrystalline CdTe.     

Preparation and characterizations of interpenetrating polymer network hydrogels of poly(ethylene oxide) and poly(methyl methacrylate)

Interpenetrating polymer network (IPN) hydrogels based on poly(ethylene oxide) and poly(methyl methacrylate) were prepared by radical polymerization using 2,2‐dimethyl‐2‐phenylacetophenone and ethylene glycol dimethacrylate as initiators and crosslinkers, respectively. The IPN hydrogels were analyzed for sorption behavior at 25°C and at a relative humidity of 95% using dynamic vapor sorption. The IPN hydrogels exhibited a relatively high equilibrium water content in the range of 13–68%. The state of water in the swollen IPN hydrogels was investigated using differential scanning calorimetry. The free water in the hydrogels increased as the hydrophilic content increased. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 258–262, 2003     

水平井产出剖面测井技术在塔河油田的应用

由于水平井中流体的流动相态和施工工艺的复杂性,造成常规的产出剖面测井技术难以适应于水平井,因此水平井产出剖面测井技术是一项技术含量高、研究难度大、生产迫切需求的工作。本文简单介绍了水平井产出剖面测井技术及爬行器施工工艺,应用该技术成功完成了塔河油田TK109H等三口水平井产出剖面测井,并总结了施工经验与存在的问题,为进一步应用该技术评价生产层段产出状况提供帮助。     

轮胎压力监测系统(TPMS)的研究

介绍了一种轮胎压力监测系统的方案设计,主要内容为系统的组成、工作原理、硬件结构框图、软件流程图设计.     

希腊神话中的文化殖民主义色彩

希腊神话作为西方文学的一个重要文学源头,其中可能具有的文化殖民主义色彩目前少有学者论及。探寻希腊神话中表现出来的其他民族在史前往希腊地区迁徙的历史,以及他们将其在神话中叙述出来的方式,挖掘希腊神话从开始就带有的文化殖民主义色彩。     

翻译教学中如何培养学生的语篇意识

阐述了培养学生在翻译过程中的语篇意识的意义.介绍了在翻译实践教学过程中,通过问题引导和分析学生翻译过程,帮助学生建立语篇概念,形成正确的语篇意识的具体做法.     

认知视角下英汉语言蕴涵的民族文化心理差异

不同的语言反映着不同民族的概念体系和价值体系,蕴涵着不同民族的文化精神和文化心理.从英语和汉语中的数字、色彩、时间、空间概念方面,分析了英汉民族的文化心理差异.     

嵌入社会责任的农业企业绩效评价研究

根据现代农业企业的特点和社会对农业企业的要求,认为评价农业企业的绩效,应该将财务指标和非财务指标综合起来加以考量.在明确绩效评价指标原则的基础上,建立了涉及企业财务、客户、内部流程、学习创新和社会责任等5个维度的农业企业绩效评价指标体系.以对丰原生化公司的综合评价为例,介绍了评价指标体系的应用效果.     

基于ATmega128单片机的自抗扰控制器设计

设计了一种基于自抗扰控制器的控制仪表.它采用ATmega128单片机作为主控制芯片,用8位数码管实现了测量值与设定值的显示,能够采集和输出4~20mA、0~10V等模拟信号,并可以用按键对控制算法参数进行设置.针对FESTO水位对象进行了控制实验,控制器运行稳定,并表现出良好的控制品质.