氧化铝基表层镁铝尖晶石的研究──Ⅰ．表层镁铝尖晶石的相结构、孔结构、表面酸性及负载钯的化学状态

对＜１０００℃焙烧的γ－Ａｌ２Ｏ３载镁体系进行了相表征，发现在基质氧化铝上形成了表层镁铝尖晶石，具有“原尖晶石结构”的γ－Ａｌ２Ｏ３则在＜１０００℃保持物相不变．进一步研究了这种氧化铝基表层镁铝尖晶石的孔结构、表面酸性以及负载耙的分散与化学状态，结果表明：氧化铝基表层尖晶石的孔结构和表面酸性由构成的氧化铝基决定，并随温度变化，表层尖晶石仅可稳定氧化铝基的物相，与其孔性质和酸性无关；负载在氧化铝基表层尖晶石上的钯，主要分布在表层镁铝尖晶石上，有强的载体一金属相互作用，以Ｐｄ０和Ｐｄ２＋两种状态存在．     

《新药化学全合成路线手册》

正本书归纳综述了新药的化学合成路线。覆盖范围为近5年美国FDA批准上市的新分子实体药共109个。针对每一个药物给出了药物简介,药物化学结构,产品上市信息,药品专利保护和市场独占权保护信息,化学全合成路线和参考文献等。合成路线大多是目前制药工业中正在使用的化学合成工艺,有较高的实用性和学术价值。对参与反应的起始原     

First-Principles Calculations of Phase Transition and Stability of Si2CN4 under High Pressure

A pressure-induced phase transition and stability in Si2 CN4 polymorphs under high pressure are studied by firstprinciples calculations. The result shows that the phase transition pressure of α- and β-Si2 CN4 to the cubic spinal phase is 29.9 GPa and 27.5 GPa predicted by thermodynamic method respectively. Under ambient condition, all of the three Si2CN4 polymorphs are metastable with positive formation enthalpy. Unlike the stability of Si3N4 polymorphs, α-Si2 CN4 is more stable than the β phase.     

《多功能金属硼酸盐合成与应用》

正本书在简要介绍金属硼酸盐的发现和研究简史、硼酸盐消费结构、硼酸盐化学组成和结构等的基础上,详细阐述了钠铵硼酸盐、偏硼酸盐、过硼酸盐、硼酸铝等多种硼酸盐的理化性质、合成工艺与用途,同时扩展了硼酸、硼酸盐抗粉化剂、氟硼酸盐、硼酸盐晶须、金属硼氢化盐及硼酸盐的应用领域等相关内容。书号:9787122306869定价:60.0元     

氧化铝基表层镁铝尖晶石的研究Ⅰ.表层镁铝尖晶石的相结构、孔结构、表面酸性及负载钯的化学状态

对＜１０００℃焙烧的的ｒ－ＡＬ２Ｏ３载镁体系进行了相表征，发现在基质氧化铝上形成了表层镁铝尖晶石 ，具有“原晶石结构”的ｒ－Ａｌ２Ｏ３则在＜１０００℃保持物相不变。进一步研究玻了这种氧化铝基表层镁铝晶石的孔结构，表面酸性以及负载钯的分散与化学状态，结果表明：氧化铝基表层晶石的孔结构和表面酸性由构成的氧化铝基决定，并随温度变化；表层尖晶石仅可稳定氧化铝基的物相，与其孔性质和酸性无关；负载在氧化铝基表     

Synthesis of Boron-Rich Cubic B（CxN1-x） Compounds

B2CN precursor is prepared by a mechanical vibration-milling process using amorphous boron, graphite and h-BN powders with mole ratio of 1：1：1. A mixture of precursor and Ca3B2N4 catalyst is treated under high pressure and high temperature. A boron rich cubic B（CxN1-x） phase is obtained after removing the catalyst by acid treatment. The average C content of the boron-rich cubic phase is about 6 at.% detected by energy-dispersive x-ray analysis spectroscopy. It is found that the highest carbon content in the cubic phase is as large as 16 at.%.     

Hardness of Wurtzite-Structured Semiconductors

rickets hardness calculations of eleven wurtzite-structured semiconductors are performed based on the microscopic hardness model. All the parameters are obtained from first-principles calculations. There are two types of chemical bonds in wurtzite-structured crystals. The overlap populations of the two types of chemical bonds in lonsdaleite are chosen as Pe for wurtzite structure. The calculated bond ionicity values of the wurtzite-structured semiconductors are in good agreement with the ionicities from the dielectric definition. When the hardness of wurtzite-structured crystal is higher than 20 GPa, our calculated rickets hardness is within 10% accuracy. Therefore, the hardness of novel wurtzite-structured crystal could be estimated from first-principles calculations.