Bi2O3、Dy2O3掺杂对8YSZ导电性能的影响

用柠檬酸溶胶-凝胶法制备了分别掺Bi2O3和Dy2O3的8YSZ前驱体凝胶,凝胶在500℃预烧,压制成圆片状后在1 300℃煅烧2 h。分别研究Bi2O3和Dy2O3的不同掺量对试样的致密度、电导率的影响。结果表明Bi2O3可促进试样的烧结,在300～400℃掺Bi2O3可提高试样的电导率,在400～700℃掺Bi2O3使试样的电导率下降。在8YSZ试样中掺Dy2O3后,试样的致密度、电导率均降低。     

Al2O3对铁矿粉烧结液相生成的影响

采用FactSage对不同Al2O3质量分数下CaO-SiO2-FeOx-MgO-Al2O3体系液相区进行热力学分析,并通过液相生成特性试验,研究高岭土型Al2O3和三水铝型Al2O3对CaO-SiO2-FeOx-MgO-Al2O3体系液相生成特性的影响。结果表明,高岭土型Al2O3和三水铝型Al2O3对液相生成特征温度的影响无明显差异,Al2O3质量分数增加,均使液相开始生成温度升高,液相生成温度区间缩小,高熔点黏结相比例增加。液相生成量与Al2O3类型质量分数相关,w(Al2O3)=1.0%时,含三水铝型Al2O3混合料液相生成量较少;w(Al2O3)=2.0%~3.5%时,含高岭土型Al2O3混合料液相生成量较少。     

CaO—SiO2—Al2O3—MgO—TiO2—FeO渣系熔融还原过程中TiC的生成机理

在实验室条件下，测定了熔融还原过程中ＣａＯ－ＳｉＯ２－Ａｌ２Ｏ３－ＭｇＯ－ＴｉＯ２－ＦｅＯ系炉渣组成以及不同供碳对ＴｉＣ生成的影响，并进行了热力学分析。研究结果表明：ＴｉＣ的生成机理与工艺条件密切相关。     

Ca3Co2O6块体的放电等离子烧结及热电性能研究

采用短时固相反应和放电等离子烧结(SR-SPS)方法, 制备了单相多晶Ca3Co2O6陶瓷块, 系统研究了制备条件及烧结工艺对Ca3Co2O6陶瓷块显微结构及热电性能的影响. 研究表明, 950 ℃下固相反应2 h即能得到单相树枝状, 尺寸约1～3 μm的Ca3Co2O6粉末, 延长焙烧时间虽然对物相影响不大, 但会引起粉末颗粒长大, 不利于SPS烧结;SPS烧结温度强烈影响着Ca3Co2O6陶瓷块的制备, 本实验范围内, Ca3Co2O6陶瓷块体的最佳制备条件为950 ℃固相反应2 h, SPS 900 ℃保温5 min, 此时Ca3Co2O6陶瓷块具有p型半导体特性, 电阻率ρ随温度的升高急剧下降, 然后趋于平缓(高于600 ℃);Seebeck系数S随温度(100 ℃以上)升高稍有下降, 热导率κ表现为先下降后增加, 在500 ℃时仅为1.73 W·m-1·K-1. 综合电性能与热性能结果, 其无量纲因子ZT随温度升高呈上升趋势, 在本实验范围内, 于700 ℃下达到最高值0.02.     

MgO和Al2O3对铁矿粉烧结液相生成的影响

为阐述烧结过程熔融机制和成矿机制,明确MgO、Al2O3质量分数对烧结液相生成和矿物组成的影响是至关重要的。利用Factsage软件计算Fe2O3 SiO2 CaO Al2O3 MgO体系的液相生成,计算氧分压在500Pa时,不同温度,不同MgO、Al2O3质量分数下体系液相生成和液相区分布的影响。通过烧结试验,分析烧结矿的矿相和矿物成分,结合软件计算得出烧结矿中MgO质量分数为2.0%、Al2O3质量分数为3.0%时其液相量、矿相、矿物成分达到最优适合烧结冶炼的标准。     

Al2O3/SiO2对烧结矿铁酸钙生成能力的影响

针对烧结矿中含铝过高而导致烧结黏结相强度差的问题,本文采用烧结杯实验,通过分析不同Al2O3/SiO2比值条件下生产的烧结矿的矿物组成与矿相结构,研究混合料中该比值对烧结矿铁酸钙的形成规律.研究结果表明:Al2O3是形成复合铁酸钙的条件,其量少时有利于针状铁酸钙的形成,可以降低烧结矿混合料的初熔温度,改善烧结矿质量.在...     

CaO-SiO2-Al2O3-Fe2O3渣系脱磷行为

利用Factsage软件计算了Al2O3含量对CaO-SiO2-Al2O3-Fe2O3四元渣系熔点和黏度的影响,并通过实验研究了在1 400℃时,CaO-SiO2-Al2O3-Fe2O3四元渣系对高磷铁水脱磷行为的影响.结果表明:渣中Al2O3的质量分数在3％～6％之间时,随着A12O3含量的增加,渣系的熔化温度迅速降低,进一步增加渣中的A12O3含量,渣系的熔化温度逐渐增加;Al2O3对CaO-SiO2-Al2O3-Fe2O3渣系的黏度影响不大;渣中Al2O3的质量分数在3％～6％之间变化时,渣系脱磷能力变化不是很大,脱磷率维持在91％左右,进一步增加渣系中A12O3的量,脱磷率逐渐下降;Al2O3对脱磷率产生影响可能是其改变了炉渣中液相所占比例,进而影响磷从铁水中向液相渣的传质过程.     

B2O3对CaO-Al2O3-SiO2-MgO-CaF2五元精炼渣系熔化特性的影响

通过半球点法研究了B2O3对40．5％-70．0％CaO-19％～45％Al2O3-SiO2-MgO-CaF2五元渣系熔化温度和完全熔化时间的影响。实验结果表明，当渣中CaO含量为40．5％～60％，CaF2 2％-10％，（B2O3％）／（CaF2％）为0．17—0．33时，渣系的熔化温度较不加B2O3的五元渣平均降低30℃，完全熔化时间平均降低49s。合适的多元脱硫精炼渣系的成分为60％CaO，19％-30％Al2O3，≤10％（MgO＋SiO2），2％～6％CaF2，（B2O3）／（CaF2）=0．17。     

Mo-La2O3烧结坯的韧化机制研究

通过扫描电镜，定点探针分析，X射线衍射分析及俄歇电子能谱分析研究了Mo-La2O3烧结坯的韧化机制，结果表明：La2O3的加入提高了烧结钼坯的横向断裂强度和韧性，Mo-La2O3O烧结坯的韧化机制源于间隙杂质在La2O3粒子表面的吸附作用。     

Visible luminescence of lanthanide ions in Ca3Sc2Si3O12 and Ca3Y2Si3O12

The crystalline materials Ca₃Sc₂Si₃O₁₂ and Ca₃Y₂Si₃O₁₂ were characterized by different crystal structures, as the former is a cubic garnet, while the latter is an orthorhombic compound. We investigated the optical spectroscopy of these materials doped with several trivalent lanthanide ions and compared the results for the two hosts. Polycrystalline samples were prepared by solid state reaction, both undoped and doped with the trivalent lanthanide ions Eu³⁺, Tb³⁺ and Sm³⁺. Emission, excitation and Raman spectra of these materials were measured at temperatures ranging from 300 to 10 K. The optical spectra were assigned and discussed, and the effects of the crystal structure of the host on the spectroscopic behaviour were addressed. The technological potential of these compounds in the field of optical materials and devices was discussed.     

Ca3N2在生成BN反应中的作用

研究了Ca₃N₂对高温常压下B₄C与NH₄CL生成hBN反应的作用.在950℃,B₄C与NH₄Cl的反应产物中含少量hBN,加入Ca₃N₂后hBN含量无明显变化;在1200℃,B₄C与NH₄Cl的反应产物中hBN含量高于950℃时的含量,加入Ca₃N₂后hBN含量明显增加.分析表明:Ca₃N₂在上述生成hBN的反应中表现出催化作用.Ca₃N₂对生成hBN反应的催化作用弱于Li₃N,而且Ca₃N₂和Li₃N都只有在熔融状态下才有催化作用.     

Superconducting Transition Temperature in YBa2Cu4O8/La2/3 Ca1/3 MnO3 / YBa2 Cu4O8 Heterostructure

YBa2Cu4O8/La2/3 Ca1/3 MnO3/YBa2Cu4O8 （ Y-124/LCMO/Y- 124） heterostructure was prepared by facing-target sputtering technique. The oscillatory superconducting transition temperature was observed when the thickness of LCMO d L is larger than critical thickness d L^CR. The metal-insulator transition temperature can only be detected at d L 〉 d L^CR. The dependence on the spacer layer in LCMO/Y-124 systems suggests strongly the interplay of ferromagnetic and superconducting couplings.     

Al2O3-V2O5体系的热力学优化

在对Al₂O₃-V₂O₅体系相图、热力学数据以及晶体结构数据进行综述与评估的基础上,采用相图计算方法对Al₂O₃-V₂O₅体系进行热力学优化.液相采用修正的似化学模型进行描述,利用对近似处理液相中存在的短程有序.将液相模型的最大短程有序设置在AlVO₄处,将VO₄3-当作液相中V₂O₅的基本组成单元.体系中AlVO₄相看作线性化合物.计算结果很好的重现了选定的实验数据,获得了一套合理、可靠、自洽的模型参数用来描述体系中各相的热力学性质,为Al₂O₃负载V₂O₅型催化剂催化性能的提高打下坚实的基础.      

Solubility of carbon in CaO-B2O3 and BaO-B2O3 slags

The solubility of carbon in molten CaO-B₂O₃ and BaO-B₂O₃ slags at high temperatures was measured to understand the dissolution mechanism of carbon into the slags. The B₂O₃-bearing slags, which have a wide range of liquids, at the temperature of interest have been applied to investigate the effect of basicity on the solubility of carbon from the saturation of acidic or basic components. The solubility of carbon, as a function of the composition of slags, shows a minimum value, and it is suggested that carbon dissolves by different mechanisms in the acidic and basic slags, respectively. From the infrared spectra measurements, the wave number indicating the B-C bond was found to be about 1150 cm⁻¹ in the acidic region of slags; hence, the incorporation of carbon into the borate network was confirmed qualitatively. The carbide capacity was compared to the nitride capacity, showing that the dissolutions of carbon and nitrogen into the slags are similar.     

Photoluminescent properties of Ca2Gd8（SiO4）6O2： Dy^3＋ phosphor films prepared by sol-gel process

There are growing interests on phosphor thin films owing to their potential application in high-resolution devices such as cathode ray tubes and flat panel display devices. The solution-based sol-gel method is one of the most important techniques for the synthesis of various functional coating films. Compounds with the apatite structure are very suitable host lattices for various luminescent ions. Ca2RE8（SiO4）6O2 （ RE=Y, Gd, La ） is a kind of ternary rare-earth-metal silicate with oxyapatite structure, which has been used as host material for the luminescence of various rare earth and mercury-like ions. In this article, Ca2Gd8（SiO4）6O2：Dy^3＋phosphor films were dip-coated on quartz glass substrates through the sol-gel process. X-ray diffraction （XRD）, atomic force microscopy （AFM）, photoluminescence （PL） spectra, as well as lifetimes were used to characterize the resulting films. AFM study revealed that the phosphor films consisted of homogeneous particles. The Dy^3＋ showed its characteristic emission in crystalline phosphor films, i.e., ^4F9/2-^6H15/2 and ^4F9/2-^6H13/2.     

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.      

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.     

La2O3对ZrO2-Y2O3-Ta2O5陶瓷材料结构及性能的影响

采用固相合成法在氧化钇部分稳定氧化锆(YSZ)陶瓷材料的基础上引入氧化物Ta2O5以及稀土氧化物La2O3取代部分Y2O3,获得一种新型的La2O3-ZrO2-Y2O3-Ta2O5陶瓷材料。分别利用X射线衍射仪、扫描电子显微镜和STA-449C热膨胀仪对材料的物相组成、微观结构及热膨胀性能进行表征。结果表明,陶瓷材料的主晶相仍为四方相,晶粒尺寸减小,在RT～1200℃温度范围内热膨胀系数有所减小。     

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.