掺钴氧化钌（RuO2/Co3O4）·nH2O复合薄膜电极的制备与表征

以六水合氯化钴(CoCl2.6H2O)和水合三氯化钌(RuCl3.3H2O)为前驱体,采用胶体法制备超级电容器用(RuO2/Co3O4)·nH2O复合薄膜电极材料。用X射线衍射仪以及CHI660C电化学工作站对该复合薄膜的物相结构及电化学性能进行表征。结果表明:当CoCl2·6H2O和RuCl3·3H2O的物质的量比n(Co):n(Ru)为2:1时,于350℃下热处理2.5 h制备的复合薄膜电极具有优良的性能,在浓度为0.5mol/L的H2SO4电解液中其比电容达到512 F/g,500次充放电循环后比电容量保持在充放电循环前的96.1%;充放电电流为0.01A时,内阻为1.2。     

共沉淀法合成CeO2/γ-Al2O3复合纳米晶的研究

以Al(NO3)3·9H2O和Ce(NO3)3·6H2O为原料,氨水为pH值调节剂,并加入少量表面活性剂PEG4000,采用化学共沉淀法制备了前驱体,前驱体经高温热处理得到含25%(质量分数)CeO2的CeO2/γ-Al2O3复合纳米晶。通过正交试验,获得了共沉淀的优化条件:pH值为9～10,反应温度约30℃,反应时间为20min,表面活性剂用量为0.44%(质量分数),前驱体热处理温度800℃为宜。使用TG/DTA、XRD、BET、IR、纯度及化学成分分析等方法对CeO2/γ-Al2O3复合纳米晶的性能进行了表征。     

球磨工艺对Al2O3/Mo复合材料组织的影响

针对原位自生Al2O3增强钼基复合材料晶粒较大的问题,采用溶胶-凝胶与高能球磨相结合的方法细化复合材料晶粒,并利用SEM、XRD对不同球磨工艺所制备Al2O3/Mo复合粉末及复合材料的组织进行了观察和分析。结果表明:随着球磨时间的延长,Al2O3/Mo复合粉末颗粒由球状变为层片状再成为细小的球状,颗粒大小由约1.5μm细化为约500nm,其中的钼晶粒不断细化;高球料比所得粉末的分散性和破碎细化程度较好;转速提高使得粉末颗粒的尺寸均匀程度降低,且伴有结块现象,不利于粉末的细化。在球料比5∶1、转速300r/min、球磨时间60h条件下获得的复合粉末,经压坯烧结可制备出Al2O3颗粒为纳米级的钼基复合材料。     

Al2O3/B4C复合材料性能的研究

采用凝胶注模成形工艺制备Al2O3/B4C芯块,研究其真空烧结性能.通过热分析仪、扫描电镜(SEM)、X射线衍射(XRD),考察了Al2O3/B4C复合材料DTA、结构、形貌和相态.结果表明:在1 600℃以上Al2O3与B4C反应,生成Al8B2O15等低熔点化合物,有利于提高Al2O3/B4C芯块致密性,但同时会产...     

铝电解用TiB2/Al2O3复合阴极的烧结与性能研究

以氧化铝溶胶为粘结剂,采用冷压烧结法制备出铝电解用TiB2/Al2O3复合阴极材料,研究了烧结温度、烧结时间和溶胶添加量对复合阴极相对密度、电阻率和抗压强度的影响。结果表明:烧结温度的提高能够增加复合阴极的相对密度,同时有利于降低复合阴极电阻率。1 400℃烧结的复合阴极相对密度可达93.83%,电阻率最低为0.56μΩ.m。随着烧结时间的延长,复合阴极的电阻率先降低后增加。烧结时间为5 h时复合阴极电阻率最低,为0.72μΩ.m。当溶胶含量为25%,1 400℃烧结5 h时,复合阴极材料性能最佳,其电阻率可达0.72μΩ.m、抗压强度为38.70 MPa。     

Al2O3界面钝化与热处理对Gd2O3-HfO2高κ薄膜电性能影响

采用磁控溅射技术在p-Si(100)衬底上生长了Gd2O3掺杂HfO2( GDH)高κ薄膜,制备了GDH/Si和GDH/Al2O3/Si两种堆栈层.结果表明Al2O3界面钝化使漏电流密度降低了两个数量级,并改善了回滞窗口和平带电压的偏移.高温N2退火对堆栈层电学性能影响明显:随着温度的增加,界面性能逐步改善,退火温度为900℃时,回滞窗口小于20 mV,积累区趋势平缓并且单位面积电容值增大,薄膜介电常数为20.     

包裹型ZrB_2-YAG-Al_2O_3复相陶瓷的制备及氧化性能研究

ZrB2具有许多优异性能,应用非常广泛。采用共沉淀法成功合成包裹型A1(OH)3-Y(OH)3/ZrB2复合粉体,再通过600℃煅烧得到了包裹型Al2O3-Y2O3/ZrB2复合粉体。包裹型Al2O3-Y2O3-ZrB2粉体在1 700℃、20MPa、4min的放电等离子烧结(SPS)条件下烧结致密化制备包裹型ZrB2-YAG-Al2 O3陶瓷。复相陶瓷的氧化增重随着氧化温度升高而增大,随着YAG-Al2O3含量增大而减小。     

中间层热处理温度对VO_2/TiO_2复合薄膜热致相变性能的影响

通过溶胶凝胶法在云母表面制备了Ti O2中间层薄膜,再在中间层上制备了VO2薄膜。通过视频光学接触角测量仪检测Ti O2薄膜的亲水性,利用XRD、傅立叶红外光谱仪和紫外可见分光光度计对复合薄膜的结构及光学特性进行分析。试验表明,紫外光激发后的Ti O2薄膜具有良好的亲水性,能够实现V溶胶的均匀涂覆。Ti O2中间层经510~560℃退火后,复合薄膜沿(011)晶面择优取向生长,复合薄膜红外屏蔽效能高,相变温度及滞后温宽都较低。中间层经460℃退火后的复合薄膜沿(111)晶面取向生长,红外屏蔽效能达到92%以上。     

Yb2O3-Y2O3-Ta2O5-ZrO2体系相稳定性研究

研究了Yb2O3-Y2O3-Ta2O5-ZrO2陶瓷材料的相稳定性。采用X射线衍射来表征材料从200℃至1 500℃的相稳定性。结果表明:经200℃至1 500℃等温热处理后,Yb2O3-Y2O3-Ta2O5-ZrO2陶瓷材料仍由单一的四方相组成,说明Yb2O3-Y2O3-Ta2O5-ZrO2陶瓷材料在低于1 500℃以下温度热处理具有良好的相稳定性。另外,该体系表现出与成分无关的高四方度,这可能是具有良好四方相相稳定性的原因。     

HNO_3胶溶对Al_2O_3薄膜性能的影响

以异丙醇铝为前驱体,HNO3为胶溶剂,采用溶胶-凝胶法制备Al2O3膜。考察HNO3浓度对溶胶及薄膜的影响,通过TG-DTG,XRD,AFM,BET等表征手段对溶胶的稳定性及黏度,薄膜的热稳定性,物相组成,表面形貌,微孔结构及分布等进行综合分析。结果表明:随HNO3浓度增大,溶胶黏度增大,HNO3浓度为5 mol/L时溶胶发生团聚;薄膜的热稳定性较好,高于500℃加热薄膜几乎没有质量损失;随烧结温度升高,薄膜中的γ-AlOOH逐渐向γ-Al2O3转变,薄膜因此变得更加稳定;薄膜表面较为平整,微孔分布均匀,平均孔直径为4.22 nm。     

CaO—SiO2—Na2O—CaF2—Al2O3—MgO保护渣系的Al2O3吸收速率和粘度

采用CaO-SiO2-Na2O-CaF2-Al2O3-MgO渣系,通过测定熔渣的粘度和Al2O3吸收速率,研究连铸保护渣的Al2O3吸收速率与粘度及化学成分之间的关系。在一定条件下,当CaO/SiO2为1.2左右时,粘度达到最小值,Al2O3吸收速率达到最大值,分别为0.10?Pa*s、8.403×10-4?kg*m-2*s-1。随着渣中Na2CO3含量、CaF2含量和MgO含量的增加,粘度减小,Al2O3吸收速率增大。随着渣中Al2O3含量的增加,粘度增大,Al2O3吸收速率减小。粘度为Al2O3吸收速率的主要控制因素。随着熔渣粘度的增加,连铸保护渣的Al2O3吸收速率逐渐减小。     

Kinetics of reduction of ferric iron in Fe2O3-CaO-SiO2-Al2O3 slags under argon, CO-CO2, or H2-H2O

The rates of reduction of ferric iron in Fe₂O₃-CaO-SiO₂-Al₂O₃ slags containing 3 to 21 wt pct Fe₂O₃ under impinging argon, CO-CO₂, or H₂-H₂O have been studied at 1370 °C under conditions of enhanced mass transfer in the slag using a rotating alumina disc just in contact with the slag surface. For a 6 wt pct Fe slag at a stirring speed of 900 rpm the observed reduction rates by 50 pct H₂-H₂O were a factor of 2 to 3 times higher than those by 50 pct CO-CO₂ and more than one order of magnitude higher than those under pure argon. The observed rates were analyzed to determine the rate-controlling mechanisms for the present conditions. Analysis of the rate data suggests that the rates under 50 pct H₂-H₂O are predominantly controlled by the slag mass transfer. The derived values of the mass-transfer coefficient followed a square-root dependence on the stirring speed for a given slag and, at a given stirring speed, a linear function of the total iron content of the slags. The rates of oxygen evolution during reduction under pure argon were shown to be consistent with a rate-controlling mechanism involving a fast chemical reaction at the interface and relatively slow mass transfer in the gaseous and the slag phases. The rates of reduction by CO-CO₂ (pCO=0.02 to 0.82 atm) were found to be likely of a mixed control by the slag mass transfer and the interfacial reaction. A significant contribution of oxygen evolution to the overall rates was observed for more-oxidized slags and for experiments with relatively low values of pCO. Assuming a parallel reaction mechanism, the estimated net reduction rates due to CO were found to be of the first order in pCO, with the first-order rate constants being approximately a linear function of the ferric concentration. This article is based on a presentation made in the “Geoffrey Belton Memorial Symposium” held in January 2000, in Sydney, Australia, under the joint sponsorship of ISS and TMS. The original symposium appeared in the October 2000 Vol. 31B issue.     

Effects of La2O3/Li2O/TiO2- Coating on Electrochemical Performance of LiCoO2 Cathode

Conventional cathode material （LiCoO2） was modified by coating with a thin layer of La2O3/Li2O/TiO2 for improving its performance for lithium ion battery. The morphology and structure of the modified cathode material was characterized by SEM, XRD, and Auger electron spectroscopy. The performance of the cells with the modified cathode material was examined, including the cycling stability, the diffusion coefficient under different voltages, and the C-rate discharge. The results showed that the cell composed of the coated cathode material discharged at a large current density, and possesses a stable cycle performance in the range from 3.0 to 4.4 V. It was explained that the rate of Li ion diffusion increased in the cell while using La2O3/Li2O/TiO2-coated LiCoO2 as the cathode and the coating layer may act as a faster ion conductor （La2O3/Li2O/TiO2）.     

Al2O3La2O3Y2O3/Cu复合材料的电弧侵蚀特性研究

采用喷射沉积和内氧化法制备出Al₂O₃La₂O₃Y₂O₃/Cu复合材料,研究该材料在直流20 V/20 A的工作条件下触点的电弧侵蚀特性,并与Al₂O₃/Cu材料进行了对比分析.利用电子天平、扫描电镜等方法分析电弧侵蚀后触点的质量变化和表面微观结构.结果表明,通过添加Y₂O₃、La₂O₃稀土氧化物颗粒,可有效降低触头材料的材料转移量.Al₂O₃La₂O₃Y₂O₃/Cu材料的抗熔焊性和抗烧损性优于Al₂O₃/Cu材料的性能.在直流阻性负载条件下Al₂O₃La₂O₃Y₂O₃/Cu阳极触头表面形成凹坑,阴极触头表面形成凸起,触点表面显示出浆糊状凝固物和喷发坑等电弧侵蚀形貌特征.      

CaO-La2O3-B2O3-Eu2O3转光玻璃的合成及荧光性质

X射线衍射研究表明CaO-La2O3-B2O3-Eu2O3体系的玻璃化温度在1025℃附近.荧光光谱和ESR谱研究表明,在CaO-La2O3-B2O3-Eu2O3玻璃体系中存在着Eu2+和Eu3+两种价态离子. 316, 360, 379, 394, 413, 462和532nm锐线激发峰和592,616和650红区发射峰分别对应Eu3+的f-f激发跃迁和5D0-7FJ (J=1,2,3)跃迁发射;351nm和427nm宽带激发峰和蓝区发射分别对应Eu2+的5d-4f激发跃迁和发射.     

CaO含量对CaF2-Al2O3-CaO-Ce2O3渣系中Ce2O3行为的影响

在Fe-Cr-Al合金中添加微量的稀土元素可显著改善合金的使用性能, 文中以电渣重熔生产Fe-Cr-Al合金所用稀土渣为研究对象, 根据离子-分子共存理论(IMCT)建立了1 823 K时CaF₂-Al₂O₃-CaO-Ce₂O₃四元渣系热力学质量作用浓度模型.结果表明:当渣系中CaO和Al₂O₃的质量百分数之比维持在1:1, 即w_CaO /w_Al2O3=1时, 随着Ce₂O₃含量增加, 渣中铈铝酸盐Ce₂O₃·Al₂O₃质量作用浓度(活度)显著增加, 但炉渣物相种类没有变化.渣系中Ce₂O₃含量分别在10 %, 20 %, 30 %, 40 %时, w_CaO /w_Al2O3值对组元活度的影响各不相同但有共同特征, 表现在处于约1.0~1.8时, CaO活度增加最迅速, Ce₂O₃活度增加, Ce₂O₃·Al₂O₃活度下降, 说明渣中CaO含量增加促进了Ce₂O₃·Al₂O₃分解而导致Ce₂O₃活度增加, 选取渣系进行熔融和X射线衍射实验, 用jade 5.0软件分析物相, 实验结果与计算一致.      

Synthesis of ZrO2-HfO2-Y2O3-Sc2O3 Nano-Particles by Sol-Gel Technique in Aqueous Solution of Alcohol

Zirconium dioxide is a significant material withgood physicochemical characteristics . It is used inmanyfields such as energysources ,material and envi-ronment . Cubic phase zirconium dioxide doped withyttria (YSZ) is alreadyin wide use in solid oxygenfu-…     

Water and solute activities of the solution systems of H2So4-Cuso4-H2O and Hci-Cuci2-H2O

The activities of water, α(H₂O), in the solution system of H₂SO₄-CuSO₄-H₂O were determined by an isopiestic method and those in the solution system of HCl-CuCl₂-H₂O by a transpiration method, both at 298 K. The activities of H₂SO₄ and H⁺ in the solution system of H₂SO₄-CuSO₄-H₂O were also determined at 298 K by the emf method. The water activities in both systems obeyed the Zdanovskii rule relatively well. The α(H₂O) experimentally determined in the sulfate system showed a satisfactory agreement with those calculated from the Robinson-Bower equation, assuming the complete dissociations of H₂SO₄ and CuSO₄, whereas a good agreement between the calculated and experimentally determined α(H₂O) for the chloride system was obtained when the formation of Cu(II) chloro-complexes was taken into consideration. The mean activity coefficients, γ_±, of solutes, including H₂SO₄, HC1, and CuCl₂ in these solution systems, were calculated at 298 K by the McKay-Perring method using the activity data. The γ_±(H₂SO₄) values in the solution system of H₂SO₄-CuSO₄-H₂O were in good agreement with those determined by the emf method. On the other hand, the γ_±(CuSO₄) were calculated at the same temperature based upon the Gibbs-Duhem equation using both measured α(H₂O) and calculated γ_±(H₂SO₄) values, because of solubility limitations.     

CaO--TiO2--Fe2O3三元系中Ca3TiFe2O8的生成机理

钒钛磁铁矿是烧结矿重要的原料之一,Ca₃TiFe₂O₈作为钒钛烧结矿中矿物被发现之后,其生成机理尚不明确.本文采用X射线衍射分析、元素能谱分析和TG-DSC分析相结合的方法,研究了Ca₃TiFe₂O₈的生成机理以及不同温度、CaO与TiO₂含量下Ca₃TiFe₂O₈的生成规律.实验结果表明,Ca₃TiFe₂O₈由Ca₂ Fe₂O₅和CaTiO₃反应生成,即CaO和Fe₂O₃反应生成Ca₂ Fe₂O₅;其后,与CaTiO₃反应生成Ca₃TiFe₂O₈.反应时间越长,Ca₃TiFe₂O₈的生成量越大,但反应温度对Ca₃TiFe₂O₈生成的影响并不明显.另外,还发现CaO含量越高,Ca₃TiFe₂O₈越易于生成,而且等摩尔Fe₂O₃和CaO下只要存在TiO₂,就会有Ca₃TiFe₂O₈生成.      

SnCl2－HgCl2－K2Cr2O7容量法测定的矿石中TFe时HgCl2用量的选择

为了保持应用已久的有汞测铁经典方法中的许多优点而减轻HgCl2对环境的污染的缺点,对方法中HgCl2的用量由5m^[1]减少为2ml进行理论上的探讨,并以试验结果加以论证。