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1.
为了探讨铝基体电沉积β-PbO2复合层的合适工艺,采用正交试验对电沉积β-PbO2-WC-TiO2-CeO2-ZrO2-SnO2复合层的工艺条件进行了优选,以镀层的表面形貌指数、锌沉积阳极槽电压为指标,确定了其最佳参数:4g/LSnO2,0g/LCeO2,4g/LWC,2g/LZrO2,2g/L TiO2;沉积时间4h,温度50℃,pH值1.5,阳极电流密度3A/dm2。结果表明:以最佳工艺沉积的β-PbO2复合层作锌电积阳极,寿命比α-PbO2镀层的长。 相似文献
2.
The compounds Gd2Ba2Cu2Ti2-xMxO11- (M = Al, Co) were prepared and characterized by X-ray diffraction. The structure was refined by Rietveld calculations. Additional investigations such as magnetic measurements and impedance spectroscopy were performed in order to determine the physical properties of Gd2Ba2 Cu2 Ti2 M011-. SQUID measurements revealed the presence of a superconducting phase in the compound with the formal composition Gd2Ba2Cu2Ti1.6Al0.4011-. A transition temperature (Tc) of 25 K was observed. 相似文献
3.
The oxidation state of the Mn activator in 2MgO · GeO2, 2MgO · GeO2 · MgF2 was shown to be 4+. The observed luminescence behavior of these phosphors was accounted for by a large crystal-field splitting.
The2T1 and2E excited states of Mn4+ were found to be close in lifetime (100-120 ώs). The slower luminescence decay in magnesium fluorogermanate is attributable
to the energy transfer between the activator and electron traps through the conduction band. 相似文献
4.
本文给出了 Si_2N_2O-Al_2O_3-La_2O_3和 Si_2N_2O-Al_2O_3-CaO 系统的亚固相图。实验结果表明:在 Si_2N_2O-Al_2O_3-CaO 系统中有一个未知结构的新化合物 CaO·Si_2N_2O,在3CaO·Si_2N_2O 和3CaO·Al_2O_3两化合物之间形成连续立方固溶体。而 Si_2N_2O-Al_2O_3-La_2O_3系统中则没有发现新化合物。在两个系统的富 Si_2N_2O区,过量的 Si_2N_2O 与 La_2O_3和 CaO 分别反应形成 Si_3N_4与 La_(10)[SiO_4]_(?)N_2(H-相)(和 CaSiO_3。所研究的这两个三元系统中,分别形成了如下几个四元相容性区。在 Si_2N_2O-Al_2O_3-La_2O_3系统内有:H-Si_3N_4-La_2O_3·Si_2N_2O-La_2O_3·Al_2O_3;H-Si_3N_4-La_2O_3·Al_2O_3-La_2O_3·11 Al_2O_3;H-Si_3N_4-La_2O_3·11 Al_2O_3-Al_2O_3;H-Si_3N_4-Al_2O_3-O′s.s;H-Si_3N_4-O′s.s-Si_2N_2O在 Si_2N_2O-Al_2O_3-CaO 系统内有:Si_3N_4-CaSiO_3-CaO·Si_2N_2O-3CaO·Al_2O_3;Si_3N_3-CaSiO_3-3CaO·Al_2O_3-2CaO·Al_2O_3·SiO_(?);Si_(?)N_(?)-CaSiO_3-2CaO·Al_2O_3·SiO_2-Al_2O_3;Si_3N_4-CaSiO_3-Al_2O_(?)-O′s.s;Si_3N_4-CaSiO_3-O′s.s-Si_(?)N_(?)O 相似文献
5.
实验得知0.5Li_2S-0.5GeS_2玻璃的电导率高于0.4Li_2S-0.6GeS_2玻璃的电导率。当在这两种组成的玻璃中分别掺杂 LiI 后,则后者的电导率可高于前者。在0.4Li_2S-0.6GeS_2玻璃中同时掺杂LiBr 和 LiI 后,其电导率约为掺杂一种同量盐玻璃电导率的两倍。本文用弱电解质理论解释了Li_2S-GeS_2玻璃经掺杂 LiBr 和 LiI 后电导率变化的原因。 相似文献
6.
I. V. Bodnar' 《Inorganic Materials》2003,39(1):10-14
It was shown by x-ray diffraction and differential thermal analysis that CuGaTe2 and CuAlTe2 form a continuous series of solid solutions. CuGaTe2, CuAlTe2, and CuAl
x
Ga1 – x
Te2 crystals consisting of large blocks were grown by the horizontal Bridgman process, and their thermal expansion and near-edge transmission and reflection spectra were measured. The thermal expansion coefficient was shown to vary linearly across the solid-solution series, while the band gap is a nonlinear function of composition. 相似文献
7.
根据硬盘基板用材料的要求,制备了MgO-A12Oa-SiO2-TiO2-Y2Oa高弹性模量玻璃(120GPa).玻璃的弹性模量随组成的变化服从Makishima-Mackenzie理论,MgO、A12O3、TiO2、Y2O3等具有较高单位体积离解能的氧化物有利于提高玻璃的弹性模量.但玻璃弹性模量的理论计算值低于测试值.这是因为Makishima-Mackenzie理论没有考虑玻璃内阳离子的具体配位状态,对MgO、Y2O3堆积密度因子的推导存在误差.因此利用Makishima-Mackenzie理论发展高弹性模量玻璃时应对MgO、Y2O3等氧化物的计算进行修正. 相似文献
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9.
The phase diagram of the TlInSe2–TlSmSe2 system was mapped out using differential thermal analysis, microstructural examination, and x-ray diffraction data. The system was found to contain a partial solid-solution series (0–9 mol % TlSmSe2 at room temperature) and a quaternary compound of composition Tl2InSmSe4, which melts congruently at 1250 K. The electrical conductivity and Hall coefficient of TlInSe2–TlSmSe2 alloys were measured as a function of temperature. With increasing Sm content, the lattice parameters of the solid solution increase linearly, while its band gap decreases. 相似文献
10.
The magnetic, electrical, catalytic, and photocatalytic properties of ZrO2–TiO2materials were studied. The ZrO2–TiO2system was shown to contain ZrO2-, TiO2, and ZrTiO4-based solid solutions. Procedures for the preparation of high-activity ZrO2–TiO2photocatalysts and photostable pigments were developed. 相似文献
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采用不同配比的Al2O3、SiO2、TiO2溶胶,通过溶胶-凝胶法制备Al2O3-SiO2-TiO2复合膜.通过凝胶时间、TG-DTG、FT-IR和AFM等表征手段对溶胶的稳定性、复合膜的热稳定性、结构特征和表面微观形貌进行综合分析.实验结果表明:SiO2溶胶含量是影响复合溶胶稳定性的主要因素,随着SiO2溶胶含量的增加,复合溶胶的稳定性越小,凝胶时间越短,制膜时间缩短;TG-DTG分析表明,350℃以后,无明显的热效应,可见三组分复合的膜热稳定性较好;FT-IR表明,整个复合体系是以Si-O-Si为主要支架结构的,并生成了更加稳定的氧桥键(Si-O-Al和Ti-O-Al-O-Si等)而形成网络结构;AFM分析表明,复合膜的孔隙率较高,具有纳米尺寸孔洞,5μm范围内膜表面不太平整,通过多次涂膜可以减小缺陷,平均孔径约为53.8nm. 相似文献
13.
The stability of uranophosphates MII(PUO6)2·nH2O(MII = Mn, Co, Ni, Cu, Zn, Cd, Pb) in water and aqueous HClO4 and NaOH solutions was studied. The acid-base limits of the existence of these compounds were determined, the products of their conversion into phases of other compositions and structures were identified and studied, and the solubility of MII(PUO6)2·nH2O was determined. From the data obtained, the solubility products and Gibbs functions of formation of uranophosphates and the solubility curves were calculated, and the speciation diagrams of U(VI), P(V), and M(II) in solutions and equilibrium solid phases were plotted. 相似文献
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E. M. Godzhaev A. M. Nazarov S. I. Mamedova A. Yu. Dzhangirov 《Inorganic Materials》2001,37(6):544-547
TlInS2–TlCeS2solid solutions were characterized by x-ray diffraction and electrical measurements. The solubility limit of TlCeS2in TlInS2was found to be 8 mol %. The electrical conductivity and Hall coefficient of TlIn1 – x
Ce
x
S2(0 x 0.08) were measured from 300 to 1100 K. It was found that, as the Ce content of the solid solution increases, the band gap decreases, and the lattice parameters increase. 相似文献
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Ti/SnO_2 Sb_2O_3 MnO_2/PbO_2阳极的性能研究 总被引:8,自引:0,他引:8
制备了一种非贵金属阳极-Ti/SnO2+Sb2O3+MnO2/PbO2,并用XRD、SEM进行了表征,计算出了电极的分形维数,测定了该电极在硫酸中的使用寿命和动力学参数,把该电极用于处理含酚废水和Pb电极进行对比.结果表明,节电33%,转化率达95%,是一种优良的电化学催化剂. 相似文献
18.
Akhilesh Prasad D. Bahadur R. M. Singru D. Chakravorty 《Journal of Materials Science》1982,17(9):2687-2692
Mössbauer, EPR and magnetization experiments have been carried out on the glass composition Na2O-SiO2-Fe2O2-Y2O3 in which yttrium iron garnet (YIG) can be precipitated by suitable heat-treatment. The measurements have been carried out on the as-quenched sample as well as samples heat-treated for 4 h at 400, 500, 600, 650, 700, 750, 810 and 850 C. Mössbauer spectra from the as-quenched sample as well as the first six samples showed a quadrupole splitting while the last two samples, as well as the sample heat-treated (i) by a two-stage process at 600 C and then at 750 C for 4 h each, and (ii) at 700 C for 40 h, showed a hyperfine as well as quadrupole splitting. The behaviour of the isomer shift (IS) and quadrupole splitting (E) with the heat-treatment temperature show significant changes at the glass transition and crystallization temperatures. The Mössbauer data have been found consistent with optical and electron micrographs which show a large variation in particle size of the precipitated magnetic phase. This has been further correlated with EPR and magnetization data. 相似文献