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.     

巯基棉富集-原子吸收光谱法测定铅锭中银量

建立了以2mol/L乙酸为吸附溶液的巯基棉分离富集铅锭中银的方法,对Pb=Ag=1×106:1样品中的铅、银分离取得良好的效果,与火焰原子吸收光谱法相结合,测定标准加料试验的回收率为95．17％～100.18％,对子铅锭中含量为0．0001％～0．006％的银,变异系数为1．72％～4．90％．     

下脚鱼排骨的食品加工

<正>我国产量最大的水产方便食品--珍味烤鱼片是以马面鱼的肌肉纤维为原料,经三去(去头、去皮、去内脏)、剖肉片、漂洗、拌调味料、摊片、干燥、烘烤、轧松、包装等十余道工序精制而成。该产品沿海许多水产企业均有生产。由于该产品滋味鲜美、食用方便、具有烤鱼特有的香味,因此产品新鲜感强烈,市场上供不应求。     

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].     

Influence of [La(EDTA)]~- on pore structure of activated alumina carrier at high-temperature

The activated alumina as a catalyst carrier were widely used in automotive exhaust catalysts under high temperature,such as,petroleum refining catalysts,hydrogenation and hydrodesulfurization catalyst carrier in China and abroad.γ-Al2O3 was the catalyst carrier that was the most widely used and the best carrier of improved specific surface area .However,the activation of the coating consisted of γ-Al2O3 were usually transformed into α-Al2O3 at 800 oC,causing increased density,reduced specific surface area,and the collapse result of pore structure.While the temperature reached 1200 oC,activation of coating detached from the carrier,the resistance of flowing gas increased,catalytic activity decreased.Addition of La2O3 stabilized the γ-Al2O3 crystal structure,which would keep the activation stability of coating at a high temperature and inhibit activity loss.The activated alumina carrier treated with the solid-pore-expanding agent containing [La(EDTA)]-that synthesized using solid and solid-hybrid approach with the thermal stabilizer lanthana and EDTA at the high-temperature had a 10-30 μm large pore porous network-like structure,after alumina was calcined at 1200 oC for 1 h.The specific surface area of four specimen were beyond 120 m2/g,while the sample specific surface area of x([La(EDTA )]-)=1% was up to 150.36 m2/g.     

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...     

Selective enrichment of TiO2 and precipitation behavior of perovskite phase in titania bearing slag

1 Introduction China is rich in mineral resources of titanium, 92.4% of which is vanadium-titanium bearing magnetite, deposited mostly around the southwestern part. About 53% titanium is in the iron concentrate after mineral processing, after smelting pro…     

溶胶-凝胶法涂覆氧化铈对铬表面氧化膜生长机制的影响

采用溶胶-凝胶法在纯铬表面涂覆纳米氧化铈，并对其在1000℃空气中的氧化行为进行了研究，对于了解稀土元素改善合金抗氧化机理及开发新型稀土掺杂陶瓷防护涂层具有重要意义．采用扫描电子显微镜（SEM）和透射电子显微镜（TEM）对铬表面氧化膜的微观形貌与结构进行观测，用激光拉曼（Raman）和X射线衍射（XRD）对铬及其涂覆纳米氧化铈样品表面氧化膜的应力水平进行测试；并用二次离子质谱（SIMS）对氧化膜内元素Cr、O及Ce的深度分布情况进行了测试．结果表明，纳米氧化铈涂层降低了铬的氧化速率，其抛物线速率常数由涂覆前的2．6×10^-6mg^2／（cm^4·s）下降为涂覆后的7．4×10^-7mg^2／（cm^4·s），并且显著细化了表面Cr2O3膜的晶粒尺寸．这种细晶氧化膜可以通过高温蠕变的方式释放掉部分膜内压应力，并呈现出褶皱特征纳米氧化铈的存在使Cr2O3膜的生长机制由原来的Cr^3＋向外扩散控制转变为O^2-向内扩散控制．X射线衍射和激光拉曼测量均反映出表面涂覆氧化铈所引起的Cr2O3膜内应力降低；此外，结合氧化膜生长机制的转变对两种应力测量结果之间的偏差进行了分析．     

Structural characterization and corrosive property of Ni-P/CeO2composite coating

Electroless Ni-P/nano-CeO2 composite coating was prepared in acidic condition, and its microstructure and corrosive property were compared with its CeO2-free counterpart. Scanning electronic microscopy (SEM), transmission electronic microscopy (TEM), X-ray diffraction spectrometer (XRD), and differential scanning calorimeter (DSC) were used to examine surface morphology and microstructure of the coating. Corrosive investigation was carried out in 3%NaCl+5%H2SO4 solution. The results showed that Ni-P coating had partial amorphous structure mixed with nanocrystals, whereas the Ni-P/CeO2 coating had perfect amorphous structure. In high temperature condition, Ni3P precipitation and Ni crystallization occurred in both coatings but at different temperatures, whereas the Ni-P/CeO2 coating had sintered phase of NiCe2O4 spinels. The anticorrosion property and passivity were improved in the CeO2-containing coating due to its less liability to undergo local-cell corrosion than its CeO2-free counterpart. During the co-deposition process, some Cen+ (n=3, 4) ions may be adsorbed to the metal/solution interface, hinder nickel's crystal-typed deposition and promote phosphorous deposition. The nano-CeO2 doping finally resulted in the coating' perfect amorphous structure and good anti-corrosive property.     

铜渣的处理与资源化

铜渣中含有大量的可利用的资源,对其回收利用日益受到人们的重视。本文总结了各种铜冶炼渣的化学成分和矿物组成,介绍了国内外处理铜冶炼渣的各种方法。通过比较各种处理方法的优点和不足,提出了一种新的能充分利用渣中的铜、铁两种资源的选择性析出的处理方法,并对相关机理进行了说明。