The Physical Properties of P2O5–Sm2O3–MnO2 Glass System

Phosphate glasses doped with samarium oxide have been made using the melt quenching technique. The density of the glass was determined using the Archimedes method while the Vickers hardness was measured using a micro-vicker tester. Both density and hardness have shown an increasing trend with the addition of a small amount of Sm₂O₃. The refractive index was characterized using UV-visible spectroscopy and the Sellmeier fitting equation was used to verify the result. The refractive index was found to vary from 1.972 to 1.807 depending on the wavelength and well agreed with the fitting curve     

碱土金属氧化物熔点和硬度变化规律与电子结构的关系

用离子化合物中正、负离子的前线轨道相互作用及静电作用的协同关系解释碱土金属氧化物熔点的变化规律，对BeO的熔点小于MgO和CaO却大于SrO和BaO的现象给出了合理的电子结构原因分析．从硬度的定义导出离子晶体的硬度与离子间距离L的平方成反比，从而从晶体结构参数定量地解释了碱土金属氧化物的硬度从BeO，MgO，CaO，SrO到BaO减小的规律．     

Ho3+/Yb3+共掺ZnO-Al2O3-GeO2-SiO2玻璃陶瓷的制备和上转换发光性质

综合ZnO-Al_2O_3-SiO_2系和锗酸盐玻璃陶瓷的优点,采用熔融-晶化法首次制备了Ho~(3+)/Yb~(3+)共掺以ZnAl_2O_4为主晶相的ZnO-Al_2O_3-GeO_2-SiO_2系玻璃陶瓷。因[GeO_4]四面体和[SiO_4]四面体都是玻璃网络形成体,讨论了GeO_2取代SiO_2对玻璃陶瓷样品硬度及发光性能的影响,最终确定GeO_2的取代量为10.55%(w/w)时,玻璃陶瓷综合性能最佳。在980 nm泵浦光的激发下,发现强的绿色(546 nm)和弱的红色(650 nm)上转换发光,并研究了不同Ho~(3+)/Yb~(3+)掺杂比对样品上转换发光的影响,最终结果表明当Ho~(3+)/Yb~(3+)掺杂比为1∶11(n/n)时样品荧光强度最强,在绿色上转换发光材料方面具有潜在的应用。     

Stable structures of oxocarbons and pseudooxocarbons of group VI

Density functional theory has been used to study the geometries, electronic structure and harmonic vibrational frequencies of the oxocarbons and the pseudooxocarbons of group VI. The ability of the maximum hardness principle for predicting the stable structures of oxocarbons and pseudooxocarbons of group VI is tested by analyzing the results of these calculations. To obtain the stable structure, the geometrical parameters and stability of molecules are compared and analyzed. Bond orders of candidate molecules are calculated by using natural bond orbital analysis. Except selenium derivatives, atoms in molecule calculations prove being useful for studying the nature of carbon heteroatom bond. Chemical hardness is also reported. This study reveals that (1) DFT gives very similar geometries and energies to ab-initio methods and (2) the maximum hardness principle (MHP) is not verified for some of these structures. Data for C₆Se₆, which are new, are presented in this work.     

Mechanical properties of the Ni filler metal layer in Si3N4 joints measured by nanoindentation

Nanoindentation experiments were done on Si₃N₄/Ni/Si₃N₄ specimens bonded at different temperatures. Tests were carried out in both the ceramic adherent and the metal filler. Results from nanoindentation experiments done across the interlayer verify that a solution of Si atoms in the Ni interlayer did not modify the mechanical properties of the metal (elastic modulus and hardness). The increase in bonding temperature produced an increase in hardness in the metal interlayer but did not affect its elastic modulus. This hardening of the Ni interlayer was related to the decrease in the shear strength of these joints. Copyright © 2004 John Wiley & Sons, Ltd.     

Colloidal properties of α-sulfonated fatty acid methyl esters and their applicability in hard water

The calcium salts of -sulfonated fatty acid methyl esters were prepared, and the physico-chemical properties such as solubility, critical micelle concentration, aggregation number, and precipitation phase boundary were studied to clarify the reasons for the good hardness tolerance manifested by -sulfonated fatty acid methyl esters.The Krafft point of the calcium salts of -sulfonated fatty acid methyl esters were not necessarily lower than room temperature, but the rate of crystallization in hard water was extremely slow compared with the calcium salt of dodecyl sulfate, which has been known as an insufficient surfactant in terms of hardness tolerance.     

水中硫酸根及其总硬度的EDTA滴定法——采用计滴微型毛细管滴定管

用EDTA微量滴定法测定了水中硫酸根及总硬度，测定过程在氨性缓冲介质中进行，采用络黑T作指示剂，用一种自制的聚乙烯微型毛细管滴定管进行滴定，滴定反应所耗的滴定剂用计滴法计数。从微滴管流出的每一小滴滴定剂的体积（通常在0．01～0．02mL之间）用重量法校正，每次滴定所耗滴定剂一般在50～200小滴之间。此方法的扩展不确定度，对硫酸根测定为0．94％与重量法相当，而精密度则优于重量法，对总硬度测定为0．82％优于常量滴定法。此方法的特点为分析快速、准确，消耗试剂少且便于携带，适合于现场或野外分析应用。     

异构现象与最大硬度原理

利用原子-键电负性均衡方法计算了700多个异构体的硬度, 通过与标准生成焓所确定的相对稳定性比较后发现, 多数异构体并不遵守最大硬度原理.