ΝΗ<Subscript>3</Subscript> decomposition in a proton conducting solid electrolyte cell

The reaction of NH₃ decomposition was studied on Ag in a proton conducting double chamber cell-reactor. The proton conductor was a strontia-ceria-ytterbia (SCY) perovskite of the form SrCe_0.95Yb_0.05O_3−α. The reaction was studied at 350–700 °C and atmospheric total pressure. The proton transference number (PTN) was calculated by simultaneous measurement of the imposed current and the proton flux and it was found to vary between 0.5 and 0.7. The effects of imposed current, temperature and inlet gas composition on the reaction rate and the PTN, were examined. Although the faradaic efficiency (Λ) remained near unity in all experiments, reaction rate enhancements (ρ) as high as 57 were achieved. An up to 90% decrease in the activation energy of the reaction was observed when protons were electrochemically “pumped” away from the catalyst.     

PHENOL RECOVERY WITH SLM USING “CYANEX 923”

The study of the phenol separation-concentration process with the hollow fiber supported liquid membrane technology has been performed. Mixtures of kerosene and CYANEX 923 were used as liquid membrane. The extractant CYANEX 923 is characterized by a high phenol selectivity and an extremely low solubility in the aqueous phase. The introduction of CYANEX 923 in the membrane composition decreases the extractant losses from the pores of the support.

The phenol separation and simultaneous concentration process has been checked. The influences of the initial concentration of phenol in the feed solution and sodium hydroxide in the stripping phase and the membrane composition on the separation rate have been investigated in a single-pass mode. The analysis of the membrane composition influence has been performed according to the steady-state mass transfer conservation equation and the associated boundary conditions, leading to the mass transfer parameters of the process     

On a new class of analytic functions associated with conic domain

The aim of this paper is to generalize the conic domain defined by Kanas and Wisniowska, and define the class of functions which map the open unit disk E onto this generalized conic domain. A brief comparison between these conic domains is the main motivation of this paper. A correction is made in selecting the range interval of order of conic domain.     

Extraction of Vanadium(V) from Mixed Chloride/Thiocyanate Solutions with Two Commercial Solvating Extractants

Studies on the extraction and separation of vanadium(V) from mixed hydrochloric acid/ammonium thiocyanate solution with CYANEX 921 and CYANEX 925 in kerosene were carried out. The effects of various factors affecting the extraction process as well as temperature were investigated. Addition of thiocyanate to the chloride solution was found to enhance markedly the extraction of vanadium. HCl solution efficiently stripped V(V). The number of stages required for extraction and stripping of vanadium ions was determined from the McCabe–Thiele diagram. Based on the obtained results, the separation of V(V) from spent catalyst leach indicates the efficiency of the proposed process.     

添加微量硅对925银合金抗硫化变色性能的影响

微量硅在925银铸造过程中可促进合金脱氧,提高合金熔体的洁净度和流动性,但过量硅会劣化合金性能。采用光学显微镜和电子显微镜研究添加微量硅(0.09%~0.15%)对925银微观组织变化的影响。结果表明,随着硅含量升高,925银合金中一次枝晶组织粗大,二次枝晶臂间距增大,当二次枝晶臂间距大于10 μm,合金断裂趋势显著增加。硅元素在925银合金中形成黑色低熔铜基共晶相,并由1~10 μm的点状相转变为8~20 μm的断续条状相,显微硬度变化与共晶二次析出相比例呈对应关系。在925银中梯度添加微量硅使合金硫化腐蚀后色差缩小,提高合金的抗硫化腐蚀变色能力。     

煤油体系中采用D2EHPA,EHEHPA,CYANEX 272从硫酸介质中萃取钒（IV）的机理及热力学（英文）

采用有机磷类萃取剂—D2EHPA,EHEHPA和CYANEX 272在煤油体系中从硫酸介质中萃取钒（IV）。考察溶液pH值、萃取剂浓度、钒离子浓度、温度对钒萃取性能的影响,并确定萃合物的组成。结果表明：随着水相pH值、萃取剂浓度和温度的升高,钒（IV）的分配比增大。D2EHPA可以在更低的pH值下萃取钒（IV）,表明其对钒的萃取能力大于EHEHPA和CYANEX 272。萃取机理研究结果表明：3种有机磷类萃取剂对钒的萃取均符合离子交换机理,在低pH值条件下萃合物组成为VOR2（HR）2,在高pH值下萃合物组成为VOR2（R表示萃取剂）。     

用固定膜萃取装置进行CYANEX 272萃取钼(Ⅵ)的机理研究

本论文用悬滴法测定了 CYANEX 272-正庚烷溶液在水相、有机相界面的张力、并根据 langmuir 吸附等温式和 Gibbs 吸附式进行理论解析,探明了 CYANEX272具有界面活性,在界面上发生吸附的作用,并且被吸附的 CYANEX 272单体在界面上发生酸解离。使用多孔质中空丝固定膜萃取进行了 CYANEX 272萃取钼(Ⅵ)的动力学研究,测定了萃取速度,并进行了理论解析,探明了 CYANEX 272萃取钼(Ⅵ)的动力学过程可以用扩散-界面反应模型进行说明。     

基于单片机和DTMF的报警系统终端

设计了一款基于电话线传输的报警系统终端,以华邦公司51系列单片机W925E240位核心,利用片上即成电话CID处理单元,结合语音录放音电路、双音多频(DTMF)发送/接收电路,配合人性化界面,可实现防盗报警的功能.该系统采用主从通信的方式,当接到一台下位机的报警信息后可以将警情转发到其它终端上,通过设置和可以对下位机进行远程控制、设置等功能.本文对该控制器的组成、硬件配置、软件设计、工作原理、功能以及技术性能进行了详细论述.     

热处理对Ag—Cu—Zn（-Sn）系925银合金力学性能和显微组织的影响

采用氩气保护水冷铜坩埚非自耗电极电弧熔炼制备了5种Ag-Cu-Zn（-Sn）系925银合金，并系统研究了热处理工艺对其力学性能和显微组织的影响。结果表明：含适量Zn、或Zn和Sn的925银合金，经700℃固溶0．5h后，硬度显著高于925Ag75Cu合金，且显微组织中出现大量退火孪晶；在200～250℃温度区间时效，硬度明显提高，且显微组织中出现浮凸状组织。     

925合金在饱和H2S盐水环境下的电化学腐蚀行为研究

采用动电位极化曲线法和电化学交流阻抗法,研究了腐蚀试验时间对925合金在饱和H2S气氛下10%的NaCl水溶液中的电化学腐蚀特性影响。结果表明,925合金的自腐蚀电位随实验时间的延长先降低再升高,腐蚀速率总体呈先增大后减小趋势,结合EIS分析表明925合金在960℃固溶处理时,其抗H2S腐蚀性能较佳。