生物法合成叶醇的研究进展

叶醇是食品和化妆品市场上最重要的香料之一,主要通过化学法合成.介绍了目前国内外生物法合成叶醇的研究状况,并试图为下一步的研究方向提出建议.     

3G模拟网络终端接入测试研究

借助CMU200模拟3G网络，Motorola 3G终端，Gemplus USIM Card以及GemXplore Admin应用软件，对3G核心技术--鉴权做了详细分析，对终端接入3G模拟网络进行研究，并成功接入3G网络。     

超硬膜β-C_3N_4的研究进展

理论分析认为β－Ｃ３Ｎ４可能是一种比金刚石还要硬的材料，它的研究成为当今材料科学的一个热点。文章论述了β－Ｃ３Ｎ４问题的由来和研究进展，以及今后的研究趋势。     

基于矩阵关系模式到2NF、3NF(保FD)的分解

利用矩阵工具，研究了到２ＮＦ、３ＮＦ（保持函数依赖）的模式分解。给出了判定２ＮＦ、３ＮＦ的若干定理，并提出矩阵行相容、矩阵包含等定义。给出了基于矩阵到２ＮＦ、３ＮＦ（保ＦＤ）的模式分解算法。     

用光折变扇形效应实现非相干图像的相干转换

利用Ｂａ１－ｘＳｒｘＴｉＯ３光折变晶体的扇形散射效应实现非相干图像的相干转换，得到非相干图像的相干正转换图像，且相干输出图像有很高的保真度，分辩率可达到２８ｌｉｎｋ ｐａｉｒｓ／ｍｍ。     

Morphological characteristics of α-Al2O3 crystallites obtained direct1y from hydro /solvothermal solvents

The morphological characteristics of α-Al₂O₃ crystallites obtained directly from hydro/solv othermal solvents are reported and the formation mechanisms of corundum morphology are discussed from crystal growth and crystal chemistry principles. The crystal growth process is considered as a process of incorporation of growth units on the growth interfaces, and the crystal morphology is determined by the linkage of the coordinated polyhedra.     

First principles study-D88 lattice stability of low-rate metalloid Ti5Si3

First principles study is reported for the band structures, site and angular momentum decomposed density of states, and the electronic charge density distributions in high-temperature structural materials D8₈-Ti₅Si₃ with the addition of low-rate metalloid: carbon, boron, nitrogen and oxygen. It shows that how the addition of metalloid atoms can stabilize Nowotny phase of Ti₅Si₃ from the viewpoint of the electron structure. Supported by the National Natural Science Fundation of China Hong Lihua: born in 1974, Graduate student     

A位非化学计量比对铌酸钾钠陶瓷极化程度的影响

研究了A位非化学计量比对铌酸钾钠陶瓷极化程度的影响。采用固相反应法制备了0.96K0.5+xNa0.5+xNbO3-0.04LiSbO3系无铅压电陶瓷,通过建立钙钛矿结构的极化模型,研究了x取不同值时,外加电场、温度对陶瓷极化及压电性能的影响。研究结果表明:A位适当过量的铌酸钾钠陶瓷极化时,对温度和电场没有强烈依赖性,可以使极化足够充分,能有效提高铌酸钾钠基陶瓷的压电性能;相反,A位不过量的铌酸钾钠陶瓷极化对温度和电场敏感,容易击穿,极化不充分,降低了铌酸钾钠基陶瓷的压电性能。     

自旋—自旋相互作用对红宝石零场分裂的贡献

本文引入自旋－自旋相互作用，计算了红宝石等３种三角晶体中Ｃｒ＾３＋离子的零场分裂，理论计算与实验值一致，研究表明，自旋－自旋相互作用对三角晶场中ｄ＾３离子零场分裂的不应忽略。     

The first-principles study on the doping effect of Re in Ni3Al

Using first-principles density function for molecules method （DMol） and discrete variational method （DVM） based on the density functional theory, we studied the doping effect of Re in Ni3Al. The structure relaxation and the alloying energy show that Re has a strong Al site preference and leads to the local deformation, which is in agreement with the experimental results and other theoretical results. In addition, the charge density difference and the bond order show that Re can strongly enhance the interatomic interaction between the nearest neighbor atoms. From the density of states and the Pauli spectrum, we find that resonance states and localized states are induced by doping Re, and the doped Re atom forms the hybridized bond with the nearest neighbor atoms.