非对称损失下的点预测问题

从统计判决理论角度考虑了非对称Linex损失下的点预测问题。定义了Linex无偏预测量并讨论了与之相关的一些结论。利用十分统计量给出了最优Linex无偏预测量。     

利用不对称交叉偶联反应合成S-(+)-萘普生

用β-氨基烷基膦的NiCl2配合物为手性催化剂,以6-甲氧基-2-溴萘和a-溴代丙酸酯的有机锌试剂为原料,通过不对称交叉偶联反应合成S-(+)-萘普生.     

对称应力模型的一个疑难

应力对称模型对显著应力梯度问题，显著微结构介质，对波长较小的动力学问题，已经表现出与实验结果的显著差异。就各向同性线弹性均匀固体的静力学问题，介绍应力对称模型的一个疑难，对于直角形区域角顶的两边承受不等的剪应力问题，对称应力模型无解。引入非对称应力模型和偶应力化解了这一疑难。分析表明，随着到边界距离的增加，非对称应力模型的解趋近于对称应力模型的解。     

Profile of the composition fractions in neutron stars

The composition fractions of β-stable neutron stars and their radial distributions are investigated based on Skyrme-Hartree-Fock theory and Tolman-Oppenheimer-Volkoff (TOV) equation. It is found that a pure neutron interior with a radius of 3.5 km can exist in the neutron stars. When the radius is greater than 3.5 km, the fractions of the proton, electron and μ⁻ appear and increase with the increment of the radius, then decrease after reaching their maximum at the radius of 8 km. These results make it possible to further study the thermal evolution and magnetic properties of the neutron stars.     

大豆油环氧化反应的研究

以聚苯乙烯磺酸型强酸性离子交换树脂为催化剂,用大豆油为原料,采用乙酸-过氧化氢一步法合成环氧大豆油增塑剂。观察了反应温度、离子交换树脂和过氧化氢用量,以及添加少量矿物酸作为质子补充源对环氧化反应的影响。结果表明,使用少量离子交换树脂催化剂和低浓度过氧化氢水溶液,在适当的条件下,经环氧化反应可以得到环氧值高于6.3的产物。并且添加少量H_3PO_4,反应温度不高于65℃时,也可以得出良好的反应结果。     

人眼的色适应对荧光屏显示色貌的影响

用双眼不对称匹配法研究人眼在观察计算机视觉显示终端彩色监视器荧光屏时,视觉系统对复杂背景的色适应及其对荧光屏显示色貌的影响.研究结果表明,背景的平均颜色和目标与背景的色差及亮度差对色适应引起的色位移有显著的影响.在定量估计人眼对复杂背景的色适应引起的色貌变化时,可以把视觉系统看作一个积分响应灵敏度取决于背景颜色和亮度平均值的信息处理系统。     

油酰乙醇胺类似物的合成

为研究油酰乙醇胺及其类似物在动脉粥样硬化中的作用.本文以油酸为原料,分别与乙醇胺、(R/S)-氨基丙醇发生酰胺化反应,生成了油酰乙醇胺(3a)、和它的两个类似物:化合物(3b)和化合物(3c);然后,再将油酰乙醇胺的双键经过环氧化和环丙烷化等反应步骤,分别生成了油酰乙醇胺的另外两个类似物:化合物4、化合物7.产物经红外光谱、核磁共振谱和质谱进行了表征.并初步测试了它们对过氧化物酶体增殖剂激活受体的作用强度.     

溶剂对TS-1催化丙烯环氧化反应的影响

溶剂对钛硅分子筛TS-1催化丙烯环氧化反应具有重要影响,该文对甲醇、异丙醇和仲丁醇3种醇溶剂及丙酮、乙腈和四氢呋喃等有机溶剂中环氧化反应活性进行了研究,实验结果活性顺序为:甲醇>异丙醇>仲丁醇>乙腈>丙酮>四氢呋喃。以催化反应机理为基础,通过电子效应、空间位阻效应、溶剂极性、物理扩散和分配、溶剂氧化副反应、环氧丙烷(PO)醚化副反应、催化剂失活和丙烯溶解度等多种因素分析了溶剂对环氧化反应的影响。电子效应、空间位阻效应和溶剂极性是影响反应的重要因素,研究工作为今后同类反应溶剂的选取提供理论根据和指导,为PO清洁生产工艺的进一步工业化奠定基础。     

Preparation of MCM-41-supported chiral Salen Mn （Ⅲ） catalysts and their catalytic properties in the asymmetric epoxidation of olefins

A secondary amino-modified mesoporous molecular sieve MCM-41 was obtained by reaction of bis(3-(triethoxysilyl)propyl)amine with MCM-41. The chiral Salen-Mn (III) complex was anchored onto the modified MCM-41 by a multi-step grafting method and two heterogenized catalysts with different Mn contents were obtained. The catalysts were characterized by XRD, N2 adsorption, ICP, FT-IR and DR UV-Vis. Their catalysis on asymmetric epoxidation of several olefins was studied with NaClO and m-CPBA as oxidants respectively. It was found that both the activity and enantioselectivity of the cata- lysts decreased after the homogeneous catalyst was heterogenized. The reasons resulting in the de- crease of catalytic performance were discussed.     

Effects of the Water in Mixed Solvent on the Epoxidation Reaction of Propylene with TS-1 Catalyst

The epoxidation reaction of propylene and hydrogen peroxide with zeolite catalyst containing titanium-silicalite (TS-1)has been studied, and the reaction in the mixed solvent of water/methanol has been discussed. It is shown that the selective of epoxidation propylene decreases while the selective of propylene glycol increases, when the water content increases in the mixed solvent of me thanol/water.