铝基体β-PbO2-WC-TiO2-CeO2-ZrO2-SnO2电沉积层的工艺优选

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。     

Doping of Gd2Ba2Cu2Ti2O11-δ

The compounds Gd₂Ba₂Cu₂Ti_2-xM_xO_11- (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 M0_11-. SQUID measurements revealed the presence of a superconducting phase in the compound with the formal composition Gd₂Ba₂Cu₂Ti_1.6Al_0.40_11-. A transition temperature (T_c) of 25 K was observed.     

Mn4+ Luminescence in 2MgO · GeO2 and 2MgO · GeO2 · MgF2

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.     

Si_2N_2O-Al_2O_3-La_2O_3和Si_2N_2O-Al_2O_3-CaO系统的亚固相关系

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     

PbBr2-PbCl2-PbF2-PbO-P2O5系统玻璃成分分析*

研究了PbBr2-PbCl2-PbF2-PbO-P2O5系统的玻璃在熔融过程中的变化.发现在玻璃的熔制过程中,元素P、Pb和Br的损失量最大.化学分析和理论计算表明,这些元素是以PbC12、PbBr2和P2O5的形式挥发的.而且,随着配料成分中含量的增加,PbCl2、PbBr2和P2O5的挥发量也随之增加.     

TlInSe2–TlSmSe2 System

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.     

ZrO2–TiO2Materials

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.     

Li_2S-GeS_2-LiI和Li_2S-GeS_2-LiBr-LiI系统玻璃的电导率

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。     

CuGaTe2–CuAlTe2 System

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 Ga_{1 – 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.     

MgO-Al2O3-SiO2-TiO2-Y2O3玻璃的弹性模量

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.     

SiO2-TiO2-ZrO2涂层的制备及其特性

用溶胶-凝胶法(sol-gel method)在不锈钢表面制备了 SiO\-2-TiO\-2-ZrO\-2系无机氧化膜(STZ).用DTA/TG、IR、XRD和SEM等手段研究了涂层制备时由凝胶向玻璃态的转变以及涂层薄膜的显微结构特点,考察了涂层对基体的保护效果. 试验结果表明,在溶胶至凝胶最终转变为无机氧化物的过程中形成了无机网络,Si4+ 和Zr4+充当了网络骨架的形成离子.涂层为无定型玻璃态,其间混有石英、锐钛矿或金红石等微晶.     

SiO_2溶胶含量对Al_2O_3-SiO_2-TiO_2复合膜的影响

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.     

State of uranophosphates MII(PUO6)2·nH2O (MII = Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Pb2+) in aqueous solutions

The stability of uranophosphates M^II(PUO₆)₂·nH₂O(M^II = 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 M^II(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.     

掺杂Mg~(2+)前后CaSi_2O_2N_2∶Eu~(2+)荧光粉发光性能研究

采用高温固相法制备CaSi_2O_2N_2∶Eu~(2+)荧光粉,由于其强度有待进一步提高,通过掺杂Mg~(2+)提高CaSi_2O_2N_2∶Eu~(2+)荧光粉的发光强度,并通过表征,分析掺杂前后发光强度的变化,晶相的结构情况和颗粒的形貌特点等。     

Study of Na2O-SiO2-Fe2O2-Y2O3 glass by Mössbauer and EPR spectroscopy

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.     

PbO-PbBr2-PbF2-P2O5系统玻璃的性质

对新研制的ＰｂＯ－ＰｂＢｒ２－ＰｂＦ２－Ｐ２Ｏ５系铅卤磷权盐玻璃的化学成分以及玻璃转变温度、密度、抗潮解性和紫外光谱等性质进行了分析。结果表明,ＰｂＯ－ＰｂＢｒ２－ＰｂＦ２－Ｐ２Ｏ５系铅卤磷酸盐玻璃具有较低的玻璃转变温度,转好的抗潮解性,密度在５．０ｇ．ｃｍ＾－３以上,并且在可见了光区域具有较好的透光经。     

不同浓度Eu~(2+)对CaSi_2O_2N_2∶Eu~(2+)荧光粉影响的研究

研究了以β-Si_3N_4为原料制备Eu~(2+)掺杂的CaSi_2O_2N_2∶Eu~(2+)荧光粉,并分析了这类荧光粉的结构特点,通过实验发现该荧光粉有很宽的激发带,可以被紫外和近可见光激发,发射出550~568nm波长的峰。Eu~(2+)与CaSi_2O_2N_2∶Eu~(2+)荧光粉的发光强度有着重要的联系。随着Eu~(2+)浓度的增加激发峰和发射峰都有一定的红移现象,当浓度超过2%时,该荧光粉的发光强度会有所下降,即出现一定的浓度猝灭现象。     

La2O3在MgO-Al2O3-SiO2-TiO2微晶玻璃中的作用

在ＭｇＯ－Ａｌ_２Ｏ_３－ＳｉＯ_２－ＴｉＯ_２玻璃中添加不同数量的氧化镧,采用差热分析、Ｘ射线衍射及电子显微镜等技术研究了氧化镧对玻璃析晶过程与力学性能的影响．氧化镧的加入使玻璃中析出α－堇青石相的温度降低;同时避免了高膨胀方石英相的析出．随着氧化镧加入量的增加,玻璃整体析晶能力下降,微晶玻璃中晶相含量减少,晶粒尺寸增大,微晶玻璃的弹性模量与硬度减小,断裂韧性增加,体现出大尺寸长柱状金红石晶粒的增韧作用．     

TlInS2–TlCeS2Solid Solutions

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 TlIn_{1 – 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.