磁性多层膜的Ф射线光电子能谱研究

用射频／直流磁控溅射法制备了ＮｉＯｘ／Ｎｉ８１Ｆｅ１９和Ｃｏ／ＡｌＯｘ／Ｃｏ磁性薄膜。利用Ｘ射线光电子能谱研究了ＮｉＯｘ对Ｎｉ８１Ｆｅ１９耦合交换场Ｈｅｘ与ＮｉＯｘ化学状态的关系以及Ｃｏ／ＡｌＯｘ／Ｃｏ磁性薄膜中ＡｌＯｘ对Ｃｏ膜的覆盖状况。结果表明：Ｈｅｘ的大小只与＋２价镍有关,单质镍和＋３价镍对Ｈｅｘ没有什么作用;在Ｃｏ／ＡｌＯｘ／Ｃｏ磁性薄膜中,Ａｌ层将Ｃｏ膜完全覆盖所需的要最小厚度为２．０ｎ     

海外文献速递

电　镀2 0 0 2 0 5 0 1　用Ｒａｍａｎ光谱分析测量Ｎｉ Ｍｏ合金镀槽的成分及Ｍｏ(Ⅵ )含量———ＭｕｒａｓｅＫ .ＪＥｌｅｃｔｒｏｃｈｅｍＳｏｃ ,2 0 0 0 ,14 7(6 ) :2 2 10 (英文 )测量了Ｎｉ Ｍｏ镀槽中ＨｘＭｏ7Ｏ6～ｘ 2 4 (ｘ =0～ 2 )、ＮｉＭｏ6 Ｏ2 4 Ｈ4 - 6 、Ｍｏ(Ⅵ )Ｃｉｔ络合物 [Ｈｒ (ＭｏＯ4 ) 2 7～ｒ-、ＨｒＭｏＯ4 Ｃｉｔ( 3～ｒ) -,(Ｃｉｔ3- =Ｃ6 Ｈ5Ｏ3- 7) ]的平衡常数 ,Ｎｉ(Ⅱ ) Ｍｏ(Ⅵ )镀槽中加入柠檬酸盐 (Ｃｉｔ)后 ,多钼酸盐分解形成Ｈｒ(ＭｏＯ4 ) 2 Ｃｉｔ( 7～ｒ) -络合物 ,并形成ＨｒＭｏＯ4 Ｃ…     

La1-xCaxFe1-yCoyO3对氧气还原的催化活性

为了提高燃料电池、金属－空气电池中氧电极的性能,本工作合成了Ｌａ１－ｘＡ′ｘＦｅ１－ｙＣｏｙＯ３（Ａ′＝Ｃａ、Ｓｒ、ＢＡ）,作为氧气还原的催化剂,制成了氧电极,在碱性介质中以Ｈｇ／ＨｇＯ为参比电极测量了电极的极化曲线,考察了组成催化剂的电催化活性和化学稳定性的影响。用ＢＥＴ法测量了催化剂的表面积,发现ｘ＝０．４时,催化剂的比表面积最大,同时电催化性能也最强,本工作表明Ｌａ０．６Ｃａ０．４Ｃｏ０．４     

SrMO3—x（M=Ti,V,Cr,Mn,Fe,Co,Ni,0≤x≤0.5）氧化物的结构及其…

本文总结了国内外对ＳｒＭＯ３－ｘ（Ｍ＝Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｆｅ、Ｃｏ、Ｎｉ，０≤ｘ≤０．５）氧化物的结构及其电行为的研究，并分析了晶体场效应对这类钙钛矿化合物结构和电性质的影响。     

La1-xSrxCoO3钙钛矿氧化物电极的物理化学和析氧电化学特性

用酒石酸辅助法制备了Ｌａ１－ｘＳｒｘＣｏＯ３系列钙钛矿氧化物,结果表明,采用该方法可在较低温度下形成高比表面的钙钛矿,Ｓｒ取代Ｌａ有助于形成均相多孔的表面,提高氧化物的比表面。电化学研究表明,钙钛矿氧化物膜电极Ｎｉ／Ｌａ１－ｘＳｒｘＣｏＯ３在碱性溶液中表现出很高的析氧电催化活性和良好的稳定性。     

La_（1－x）SrxCoO_（3－y）导电陶瓷制备工艺的研究

用固相反应法制备了Ｌａ＿（１－ｘ）Ｓｒ＿ｘＣｏＯ＿（３－ｙ）导电陶瓷材料，研究了制备工艺对烧结性能的影响。实验结果表明：烧结体的致密度取决于预烧温度、烧成温度及保温时间，此外还与成型方法等因素有关。在１０００～１３００℃保温２～１５ｈ获得了高密度、导电性良好的立方钙钛矿型Ｌａ＿（１－ｘ）Ｓｒ＿ｘＣｏＯ＿（３－ｙ）（ｘ＝０．５，０．６）陶瓷材料。用Ｘ射线分析了材料的相组成和结构。     

热电池及其阳极材料的研究与发展

叙述了热电池的发展过程，以及Ｃａ／ＣａＣｒＯ４和ＬｉＭｘ／ＦｅＳ２电池体系的电化学性能，着重介绍了ＬｉＭｘ／ＦｅＳ２热电池阳极材料的结构与电极性能，指出Ｌｉ－Ｂ合金是一种最有应用前景的阳极材料。     

磁性材料在低温技术中的新应用

研究了Ｅｒ（ＮｉＣｏ）＿２系新型磁性蓄冷材料的制备和材料的比热等物理性能，并且将该材料用于Ｖ－Ｍ制冷机进行了制冷实验。结果表明，Ｅｒ（ＮｉＣＯ）＿２系材料在２０Ｋ以下的比热远大于传统蓄冷材料铅，该材料作为蓄冷材料使用时，明显提高了制冷机的效率。     

TiO2对ZrO2—NiCr金属陶瓷烧结特性和相稳定性的影响

本文研究了ＴｉＯ２掺入对ＣａＯ稳定ＺｒＯ２（简称ＣａＳＺ－ＮｉＣｒ）金属陶瓷烧结特性的影响，测定了ＣａＳＺ－ＮｉＣｒ－ＴｉＯ２金属陶瓷烧结样品的密度和显微硬度，结果表明，ＴｉＯ２的掺入能提高ＣａＳＺ－ＮｉＣｒ金属陶瓷的烧结密度和显微硬度，对ＣａＳＺ－ＮｉＣｒ金属陶瓷有助烧结作用。金相观察表明，ＴｉＯ２的掺入改变了ＮｉＣｒ相在金属陶瓷中的形貌，说明了ＮｉＣｒ与ＣａＳＺ的浸润性有一定的改善。ＸＲＤ和Ｅ     

汽轮机中压阀杆镀铬

介绍了３５ＣｒＭｏＡ调质镀铬，淬火后镀铬，２Ｃｒ１２ＮｉＭｏＷＶ、２５Ｃｒ２ＭｏＶ氮化后疲劳试验以及现场测试研究，发现了氮化和淬火后镀铬的试件使用寿命大大提高。     

Removal of Zn(II), Cu(II), Ni(II), Ag(I) and Cr(VI) present in aqueous solutions by aluminium electrocoagulation

The performance of an electrocoagulation system with aluminium electrodes for removing heavy metal ions (Zn2+, Cu2+, Ni2+, Ag+, Cr2O7(2-)) on laboratory scale was studied systematically. Several parameters - such as initial metal concentration, numbers of metals present, charge loading and current density - and their influence on the electrocoagulation process were investigated. Initial concentrations from 50 to 5000 mg L(-1) Zn, Cu, Ni and Ag did not influence the removal rates, whereas higher initial concentrations caused higher removal rates of Cr. Increasing the current density accelerated the electrocoagulation process but made it less efficient. Zn, Cu and Ni showed similar removal rates indicating a uniform electrochemical behavior. The study gave indications on the removal mechanisms of the investigated metals. Zn, Cu, Ni and Ag ions are hydrolyzed and co-precipitated as hydroxides. Cr(VI) was proposed to be reduced first to Cr(III) at the cathode before precipitating as hydroxide.     

Corrosion resistance of multilayer coatings of nanolayered Cr/Ni electrodeposited from Cr(III)-Ni(II) bath

In this study the corrosion resistance of chromium and nickel single layers and multilayer coatings of nanolayered Cr/Ni, electrodeposited from Cr(III)-Ni(II) baths on low carbon steel substrates, has been studied. The coatings were electrodeposited from a bath using pulse current and modulated agitation. The total thickness of single layer and multilayer coatings was fixed at 5 μm and multilayer coatings with different modulation wavelengths and Cr to Ni thickness ratio were electrodeposited. Corrosion behavior of coatings was then studied by using potentiodynamic polarization test and electrochemical impedance spectroscopy in 0.1 M H₂SO₄. The results showed that Cr and Ni single layers had low corrosion resistance due to the presence of surface cracks and pores, respectively. On the other hand, optimized 20 nm Cr/50 nm Ni multilayer deposition significantly improved corrosion resistance.     

Electroreduction of H2O2 by Co3O4 and NiCo2O4 nanowires and beta-Ni(OH)2 nanoplates grown on Ni foam

Nanowires (Co3O4 and NiCo2O4) and nanoplates (beta-Ni(OH)2) grown on Ni foam are successfully prepared by a template-free method and used as cathode electrodes for the electroreduction of H2O2, in an alkaline medium. Catalytic performance is investigated via cyclic voltammetry and chronoamperometry. The Co3O4 and NiCo2O4 nanowire electrodes exhibit much better catalytic activity, stability, and mass transfer properties for H2O2 electroreduction than pressed Co3O4 and NiCo2O4 nanoparticle/carbon/PTFE electrodes. A current density of 101.8 mA cm(-2) and 122.7 mA cm(-2) are respectively achieved on Co3O4 and NiCo2O4 nanowire electrodes at -0.4 V in 0.4 mol/L H2O2, and 3.0 mol/L NaOH solution at room temperature.     

A redox-stable efficient anode for solid-oxide fuel cells

Solid-oxide fuel cells (SOFCs) promise high efficiencies in a range of fuels. Unlike lower temperature variants, carbon monoxide is a fuel rather than a poison, and so hydrocarbon fuels can be used directly, through internal reforming or even direct oxidation. This provides a key entry strategy for fuel-cell technology into the current energy economy. Present development is mainly based on the yttria-stabilized zirconia (YSZ) electrolyte. The most commonly used anode materials are Ni/YSZ cermets, which display excellent catalytic properties for fuel oxidation and good current collection, but do exhibit disadvantages, such as low tolerance to sulphur and carbon deposition when using hydrocarbon fuels, and poor redox cycling causing volume instability. Here, we report a nickel-free SOFC anode, La0.75Sr0.25Cr0.5Mn0.5O3, with comparable electrochemical performance to Ni/YSZ cermets. The electrode polarization resistance approaches 0.2 Omega cm2 at 900 degrees C in 97% H2/3% H2O. Very good performance is achieved for methane oxidation without using excess steam. The anode is stable in both fuel and air conditions, and shows stable electrode performance in methane. Thus both redox stability and operation in low steam hydrocarbons have been demonstrated, overcoming two of the major limitations of the current generation of nickel zirconia cermet SOFC anodes.     

Complete oxidation of ethylene over supported gold nanoparticle catalysts

Complete oxidation of ethylene was performed over supported noble metals or transition metals oxide catalysts and on monoliths under atmospheric pressure. Gold nanoparticles on Al2O3 or MxOy(M = Mo, Fe, Mn) were prepared by impregnation, coprecipitation, deposition, and dispersion methods. Nanoparticles prepared by impregnation method were irregular and very large above 25 nm, but those by coprecipitation and deposition method were uniformly nanosized at 4-5 nm. The gold nanoparticle were outstandingly active in catalyzing oxidation of ethylene. The activity order of these catalysts with preparation methods was deposition > coprecipitation > impregnation, and Au/Co3O4 prepared by deposition method showed the best performance in ethylene oxidation. The addition of gold particles to MxOy/Al2O3 catalyst enhanced the ethylene oxidation activity significantly. The main role of the gold nanoparticles apparently was to promote dissociative adsorption of oxygen and to enhance the reoxidation of the catalyst.     

多孔Ni-WC复合电极的制备及其在酸性溶液中的电催化析氢性能

目前,关于多孔Ni-WC电极的电催化析氢(HER)性能的报道较少。以多孔海绵镍为基体,采用复合电沉积制备多孔Ni-(WC)x复合电极。运用扫描电镜(SEM)和X射仪线衍射仪(XRD)表征电极的表面形貌和微观结构,通过阴极极化、电化学阻抗(EIS)、循环伏安、计时电流法研究多孔Ni-(WC)x电极在0.5 mol/L H2SO4溶液中的电催化析氢性能。结果表明:与多孔基体Ni电极相比,多孔Ni-(WC)x电极具有较低的析氢过电位、较低的电化学反应阻抗、较小的表观活化能以及较大的交换电流密度;随着镀液中WC浓度的升高,所制备的多孔Ni-(WC)x电极的电催化析氢活性增强,其中Ni-(WC)40电极的表观交换电流密度是多孔Ni基体电极的966.7倍,其表观活化能为5.95 kJ/mol,并具有较好的耐蚀性和析氢稳定性。     

Sintering Caβ″/β/α-Al_2O_3 High Temperature Oxygen Sensor

An extended-life and ultra-low oxygen sensor has been fabricated by using polycrystalline Caβ″/β/α-Al2O3 as a solid electrolyte. Five reference electrodes CaO+O2, Caβ″/β/α-Al2O3 (powder)+O2,Cr+Cr2O3, Nb+NbO and Mo+MoO2 were tested in order to select a better reference electrode for this sensor. The limit of determining oxygen activity and the extended-life of the sensor were also tested in this study.     

Extractive removal of chromium (VI) from industrial waste solution

Extractive removal of Cr (VI) was carried out from chloride solutions using cyanex 923 mixed with kerosene. The efficiency of this extractant was studied under various experimental conditions, such as concentration of different mineral acids in the aqueous phase, concentration of cyanex 923 and Cr (VI) present in the initial aqueous feed, temperature and time of extraction, organic to aqueous (O/A) phase ratio. Percentage Cr (VI) extraction decreases with the increase in temperature at varying concentration of cyanex 923. The interference of the impurities usually associated with Cr (VI) such as Cr (III), Cu, Ni, Fe (II), Zn, Chloride and sulphate, etc., were examined under the optimized conditions and only Zn was found to interfere. Under the optimum experimental conditions 98.6-99.9% of Cr (VI) was extracted in 3-5 min at O/A of 2 with the initial feed concentration of 1g/L of Cr (VI). The extracted Cr (VI) was quantitatively stripped with 1M NaOH and the organic phase obtained after the stripping of Cr (VI) was washed with dilute HCl solution to neutralize any NaOH trapped/adhered to the solvent and then with distilled water. This regenerated solvent was reused in succeeding extraction of chromium (VI). Finally a few experiments were performed with the synthetic effluent from an electroplating industry.     

混凝土腐蚀监测用参比电极制作及电化学性能研究

参比电极对监测混凝土中钢筋的电位至关重要。使用凝胶作为电极内部电解质、水泥浆作为渗透层,制成Ag/AgCl凝胶参比电极。在混凝土模拟液中测试了电极电位的稳定性、电极的温度系数以及氯离子含量对电位的影响,通过动电位和恒电流极化测试了电极的抗极化性能,并在混凝土中进一步研究了电极电位的时变特性。结果表明,电极电位有良好的稳定性和可靠性,电极温度系数较小,氯离子含量对电极电位的影响可以忽略,电极抗极化性能优良。研制的电极可用于实时监测混凝土内部钢筋的腐蚀电位,为钢筋混凝土构件寿命预测提供参考。     

船用吊杆0Cr16Ni5Mo不锈钢的焊接

概述了与0Cr16Ni5Mo马氏体不锈钢配套的焊接材料、焊后热处理制度以及适用的焊接工艺。试验选定采用M831A焊条,双U型坡口双面对称焊,焊后进行950℃/2h油淬+500℃/10h回火,得到的焊接接头性能完全达到指标要求。