铜渣贫化的选择性还原过程

借助于金相分析、SEM和EDX等方法,研究炼铜炉渣加炭粉、通惰性气体搅拌选择性还原贫化过程。结果表明,通过选择性贫化过程,渣中残余铜含量可由5％降低到0．35％以下。随气体搅动时间延长,渣中Fe3O4含量降低,二价铁含量增加,有效地降低了渣黏度．促进冰铜滴沉降。在还原过程中,渣中Fe3O4含量逐渐降低,渣中主要存在的相组成为残余磁性氧化铁、(FeO)2·SiO2及FeO·CaO·SiO2的连续固溶体。每1kg铜渣配人17g炭粉既可满足还原反应要求。     

功能化离子液体催化合成甘油单月桂酸酯

合成了由吡啶、N-甲基咪唑、N-甲基-2-吡咯烷酮提供有机阳离子, 磷钨酸、对甲苯磺酸提供阴离子的6种离子液体。使用NMR、FT-IR和TG对离子液体表征, 并考察它们催化甘油与月桂酸酯化的催化效果。结果表明, 这些离子液体都具有较好的热稳定性, 以1-(丁基-4-磺酸基)-3-甲基咪唑磷钨酸盐离子液体的热稳定性最好。在最佳条件使用离子液体催化甘油与月桂酸反应时, 阴离子的种类对月桂酸的转化率影响较大, 以对甲苯磺酸为阴离子的离子液体催化反应时, 月桂酸转化率较以磷钨酸为阴离子的离子液体的高;1-(丁基-4-磺酸基)-3-甲基咪唑对甲苯磺酸盐离子液体做催化剂时甘油单月桂酸酯的产率最高。催化剂重复使用性方面, 离子液体重复使用5次催化活性没有明显变化。     

硅酸钠催化制备碳酸甘油酯

针对催化制备碳酸甘油酯过程中催化剂易失活、难回收的问题,以Na2Si O3·9H2O为原料,经焙烧、研磨、过筛等工艺处理后,制备得到了易分离且可循环使用的固体碱催化剂,并用于催化甘油与碳酸二甲酯的酯交换反应.探讨了催化剂的粒度和煅烧时间对催化剂活性的影响,以及甘油与碳酸二甲酯的摩尔比、催化剂用量、反应时间等反应条件对酯交换反应的影响.结果表明,当催化剂用量为反应物质量的5%且甘油与碳酸二甲酯的摩尔比为1∶4时,在75℃反应2.5 h后甘油转化率高达97.8%,碳酸甘油酯收率为95.5%.     

Influence of Nanometric Ceria Coating on Oxidation Behavior of Chromium at 900 ℃

Isothermal and cyclic oxidation behaviors of chromium samples with and without nanometric CeO2 coating were studied at 900℃ in air. Scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and high-resolution electron microscopy （HREM） were used to examine the morphology and microstructure of the oxide film. It was found that ceria coating greatly improved the oxidation resistance of Cr both in isothermal and cyclic oxidizing experiments. Acoustic emission （AE） technique was used in situ to monitor the cracking and spalling of oxide film, and AE signals were analyzed in time-domain and number-domain according to related oxide fracture model. Laser Raman spectrometer was also used to study the stress of oxide film formed on Cr with and without ceria. The improvement in oxidation resistance of chromium is believed mainly due to that ceria greatly reduced the growth speed and grain size of Cr2O3. This fine grained Cr2O3 oxide film might have better high temperature plasticity and could relieve parts of the compressive stress by means of creeping and maintained ridge character and relatively lower level of internal stress. Meanwhile, ceria application reduced the size and number of interfacial defects, remarkably enhanced the adhesive property of Cr2O3 oxide scale formed on Cr substrate.     

基于主成分分析法的泡菜风味马铃薯饼干研制

为开发以马铃薯粉为原料的新型风味产品,提高马铃薯粉的综合利用价值,将改性的泡菜粉加入到马铃薯饼干中,通过单因素和正交试验优化配方工艺,利用主成分分析法对产品进行感官评定、质构分析和营养评价。结果表明,泡菜风味马铃薯饼干的最优配方为低筋面粉145 g、奶粉15 g、鸡蛋15 g、牛奶40 g、黄油35 g、白砂糖30 g、泡菜粉13 g、马铃薯粉22 g、泡打粉4 g。复配粉过140目筛有利于提高产品质构和感官品质。产品营养评价结果显示,泡菜风味马铃薯饼干是一种高膳食纤维、高蛋白质、低热量的新型功能性营养食品,具有良好的市场推广前景。     

不同pH值下制备的镍-磷化学镀层相结构及热稳定性

在硫酸镍体系中,pH值为4.5、5.5和6.5的情况下分别制备出3种镍-磷化学镀层,目的在于研究pH值变化对镀层微观结构、内应力水平及热稳定性的影响。采用激光弯曲（LC）应力测量方法对3种镍-磷镀层的应力值进行测量;用电感耦合等离子质谱（ICPM）测量镀层中的磷含量;用扫描电镜（SEM）和配备能量散射谱的透射电镜（TEM/EDS）对镀层的表面形貌及内部相结构进行观测;用差热分析仪（DSC）对镍-磷镀层在高温下的相变规律及热稳定性进行研究。结果表明,pH值为4.5和6.5时制备的镍-磷镀层分别为完整的非晶态和纳米晶结构;pH值为5.5时制备的镍-磷镀层为部分非晶态与纳米晶的混合结构,并且该镀层具有介于前两种镀层之间的P含量及内应力水平。pH值为5.5时制备的镍-磷镀层在经历250℃热处理时发生明显的开裂,TEM测试表明微裂纹起源于Ni/Ni-P相界面;而pH值为4.5和6.5时镍-磷镀层所表现出的高热稳定性分别在于前者更低的拉应力水平及后者的充分的纳米晶结构。pH值为6.5时制备的镍-磷镀层虽然有最高的拉应力值,但其内部充分细小的纳米晶结构会有效避免局部应力集中的发生。此外镀层中可能存在的“反Hall-Petch效应”也是其耐热性能好的原因之一。     

纳米CeO2搀杂对Ni-P化学镀层微观结构与耐蚀性能的影响

引言 化学镀Xi-P镀层因其良好的耐磨性、耐蚀性及可焊性而被广泛应用于化工、航空航天及电子封装领域[1-2].镀层的力学性能及化学稳定性主要取决于其内部的微观结构及磷含量,此外,镀层在高温条件下的相变规律也被广泛研究[3-6].     

Oxidization mechanism in CaO-FeOx-SiO2 slag with high iron content

Oxidization mechanism in CaO-FeOx-SiO2 slag with high iron content was investigated by blowing oxygen into molten slag so as to oxidize Fe（ Ⅱ）. The relationship between Fe（ Ⅱ ） content and oxidizing time at different temperatures was obtained by chemical analysis. Microstructure of slag was observed by metallographic microscope and SEM. Phases compositions were ascertained by EDXS and XRD. Grain size and crystallizing quantity of magnetite（Fe3O4 ） were determined by image analyzer. The oxidizing kinetic equations were deduced. Confirmed by graphical construction method, Fe（ Ⅱ ） oxidizing reaction in CaO-FeOx-SiO2 slag system is of first order, and the reaction apparent energy Eo is 296. 67 kJ/mol in the pure oxygen and 340. 30 kJ/mol in air. The enrichment and crystal growth mechanism of magnetite（Fe3O4 ） phases were investigated. In oxidizing process, content of fayalite declines, while that of magnetite（Fe3O4 ） increases, and iron resources enrich into magnetite（Fe3O4 ） phase. All these provide a theoretical base for compressive utilizing of those slags.     

Effects of lanthanum ion-implantation on microstructure of oxide film formed on Co-Cr alloy

Isothermal and cyclic oxidizing behavior of Co-40Cr alloy and its lanthanum ion-implanted samples were studied at 1000 ℃ in the air by thermal-gravimetric analysis （TGA）. Scanning electronic microscopy （SEM） and transmission electronic microscopy （TEM） were used to examine the morphology and structure of oxide film after oxidation. Secondary ion mass spectrum （SIMS） method was used to examine the binding energy change of chromium caused by La-doping and its influence on the formation of Cr2O3 film. laser Raman spectrum was used to examine the stress changes within the oxide film. It was found that lanthanum implantation remarkably reduced isothermal oxidizing rate of Co-40Cr and improved anti-cracking and anti-spalling properties of Cr2O3 oxide film. The reasons for the improvement were mainly that the implanted lanthanum reduced the grain size and internal stress of Cr2O3 oxide and increased high temperature plasticity of the oxide film. Lanthanum mainly existed on the outer surface of Cr2O3 oxide film in the form of fine La2O3 and LaCrO3 spinel particles.     

基于特高频传感器和TDOA数据库的电力变压器局部放电的定位

提出了一种基于特高频传感器和信号到达时间差来定位电力变压器内部局部放电的新方法.通过仿真变压器内部所有可能的放电点,建立TDOA数据库,采用切线传输模型和弗洛伊德(Floyd)算法解决信号在变压器内部遇到铁心等障碍物的传输情况.