新铌酸盐Ba5LnZnNb9O30(Ln=Y,La)的合成、结构与介电性能

在BaO-Ln2O3-ZnO-Nb2O5(Ln=Y,La)体系中通过固相反应法合成了填满型钨青铜结构的新铌酸盐Ba5YZnNb9O30与Ba5LaZnNb9O30.采用X射线衍射分析和扫描电镜进行了结构分析,并进行了介电性能测试.结果表明,Ba5YZnNb9O30为弛豫性铁电体,10kHz时的居里温度为25℃;室温时为四方钨青铜结构铁电相,晶胞参数a=1.25255(4)nm,c=0.39530(2)nm;1MHz时陶瓷体的室温相对介电常数为456.Ba5YZnNb9O30在室温下为四方钨青铜结构顺电相,晶胞参数a=1.25731(3)nm,c=0.39812(2)nm;频率为1MHz时,其陶瓷的室温相对介电常数为316.     

核-壳结构P(AM-co-MAA)-W-Ag复合微球的制备

以丙烯酰胺(acrylamide, AM)和甲基丙烯酸(methacrylic acid, MAA)的共聚微凝胶(P(AM-co-MAA))为模板, 通过离心沉积法将钨粉沉积于高分子微凝胶表面, 得到具有核-壳结构的P(AM-co-MAA)-W复合微球; 再以经聚乙烯基吡咯烷酮(PVP)修饰的P(AM-co-MAA)-W复合微球为模板, 在硝酸银溶液中充分溶胀后, 通过向反相悬浮体系中缓慢通入氨气, 制备得到了具有核-壳结构的P(AM-co-MAA)-W-Ag双金属复合微球材料. 实验发现, 通过改变制备过程中AgNO3的初始浓度和PVP的用量等条件, 可以改变复合微球表面银的沉积量; 并结合实验结果初步提出了银的形成机理, 即PVP的存在, 不仅可以作为稳定剂固定Ag+离子, 同时可以作为还原剂促进Ag+还原为Ag的反应.     

Si adhesion interlayer effects in hydrogen passivated Si/W soft X-ray multilayer mirrors

The use of hydrogen passivation of the silicon layers in Si/W soft X-ray reflective multilayer mirrors is investigated. Standard passivation, corresponding to Si:H/W structures, led to reduced growth properties of the W layers. The additional use of atomically thin Si adhesion layers, corresponding to Si:H/Si/W, led to improved growth and increased soft X-ray reflectivity. The effects taking place at the interfaces are analysed by bright field planar TEM and in situ X-ray reflectivity, and are described in terms of interface and surface energies, with quantitatively analysis of intermixing, materials density, and geometrical optical effects.     

电感耦合等离子体原子发射光谱法测定钨合金中镍、铁、钴和锰

采用电感耦合等离子体原子发射光谱法测定钨合金中镍、铁、钴和锰的含量。优化的试验条件如下:1柠檬酸溶液用量为2mL;2过氧化氢溶液用量为12mL;3称样量为0.100 0g;4氨水溶液用量为2mL。选择镍、铁、钴、锰的分析谱线分别为221.647,233.280,228.616,259.373nm。4种元素在一定的质量浓度范围内与其发射强度呈线性关系,方法的检出限(3s/k)在0.018~0.083mg·L-1之间。方法应用于标准物质(JBWY05901)的分析,测定值与认定值相符。方法用于生产样品和合成样品的分析,测定值的相对标准偏差(n=6)在0.72%~3.9%之间。     

Characterization of h-WO3 nanorods synthesized by hydrothermal process

Hexagonal tungsten oxide nanorods have been synthesized by hydrothermal strategy using Na₂WO₄·2H₂O as tungsten source, aniline and sulfate sodium as structure-directing templates. Techniques X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy have been used to characterize the structure, morphology and composition of the nanorods. The h-WO₃ nanorods are up to 5 μm in length, and 50–70 nm in diameter.     

辉光放电质谱法测定钨钛合金中的微量杂质元素EI北大核心CSCD

采用辉光放电质谱法直接测定钨钛合金中的杂质元素。对放电电流、气体流量和预溅射时间等条件进行优化,用仪器内置的标准相对灵敏度因子(RSFstd)进行半定量分析。同时用已定值的钨钛合金作为标样校正仪器,获得校正后的相对灵敏度因子(RSFWTi),再应用于定量分析。结果表明,未校正测量值与参考值比值在0.5~1.6之间,相对标准偏差(RSDs)小于5%,满足半定量分析要求。经RSFWTi校正的测量值与电感耦合等离子体质谱法(ICP-MS)测得的结果比较,相对偏差(RD)小于20%,该方法适用于合金中杂质元素定量分析。     

Comparison of electrochromic characteristics of electrochromic device upon various sintering methods of sol-gel based WO3 electrode

Tungsten oxide is an electrochromic material, from which thin films are conventionally fabricated via heat treatment. Here, we develop a flash light sintering method to reduce sintering time; sintering delivers instantaneous photon energy created via the photothermal effect. The electrochromic efficiency of device with a flash light-sintered electrode was 88.50 cm²/C, about 1.46-fold greater than that of the device with a heat-sintered electrode. The diffusion coefficients of the former device were 1.35- and 1.46-fold greater than those of the latter device during bleaching and coloring, respectively. Therefore, a new way of sintering electrode was studied to show that the device with flash light–sintered electrode demonstrate better electrochromic performance than the device with heat-sintered one by enabling amorphous phase formation.