含氨基酸的手性化合物外消旋体的制取方法

综述了近年来含氨基酸的手性化合物外消旋体的制取方法,并展望了其研究发展的前景。     

DuPHOS在不对称催化氢化中的研究进展

介绍了一种新颖的具有C2对称性的手性双磷杂环戊烷配体DuPHOS，此配体在烯酰胺类、2－烷基琥珀酸类、α－羟基醌类、开链烯醇酯类、酮类等众多类型底物的不对称催化氢化反应中显示出了极高的对映体选择性，本文对此配体的最新研究进展进行了综述。     

土—结构相互作用体系的非线性随机地震反应

对土—结构相互作用体系的非线性进行随机分析,将地震地面运动模拟为零均值平稳高斯过程,建立了土—结构相互作用体系的运动方程.考虑多层剪切型钢筋混凝土框架结构非线性和地基土的非线性以及基础埋深对相互作用的体系反应的影响,把地基土的作用转化为作用在基础边界上的弹簧-阻尼器.算例表明:地基土的非线性特性所造成的层间错动比上部结构非线性特性所造成的层间错动大,也就是说,考虑地基土非线性特性比仅考虑上部结构非线性特性结构体系的破坏更严重.     

微分代数区间动力系统的稳定性与平稳振荡

研究了连续微分代数区间动力系统的稳定性与周期解的存在、唯一稳定性问题.利用广义Lyapunov方法给出了其稳定性的充分条件,同时讨论了其解的有界性.在此基础上,给出了其周期解的存在性、唯一性和稳定性的保证性条件.提供的例子说明,文中方法具有可行性.     

Structural and vibrational properties of high-dielectric oxides, HfO2 and TiO2: A comparative study

Within the framework of density functional theory, we have computed structural and vibrational properties of high-κ dielectric oxides, HfO₂ and TiO₂. We have considered different polytypes of these oxides and computed the corresponding static dielectric constants in order to investigate what are the more promising materials suitable for technological application. We found the flourite phase of hafnium dioxide, that is a promising candidate as gate oxide in ultra-scaled complementary metal-oxide-semiconductor (CMOS) technology, is structurally unstable due to the presence of soft phonon modes that have wave-vectors in the region of the Brillouin zone containing the K- and X-points. According to our results, the fluorite TiO₂ is structurally unstable as well but, contrary to HfO₂, the soft phonon modes have wave-vectors in the whole Brilouin zone. Calculations of the thermodynamical properties of the baddeleyite HfO₂, the stable phase at ambient condition, complete the work.     

基于时域方法的输电线路两点异相故障测距

提出了一种利用双端电压电流同步采样值进行高压短输电线路两点异相故障的时域测距方法。该方法基本上不受系统运行方式和过渡电阻大小影响。所有解算均在相坐标中进行,避免了两端电气量的坐标变换。最小二乘技术的应用从理论上保证了该测距算法具有较高精度。对于一点故障测距问题,该方法同样有效。     

Selective recognition in molecularly imprinted polymer and its chromatographic characterization for cinchonine

A molecularly imprinting polymer (MIP) was synthesized via bulk polymerization under different conditions using anti-ague drug cinchonine (CN) as template. Infrared spectra (IR) results show that the template CN and functional monomer α-methyl acrylic acid (MAA) formed complexes before polymerization and the structure of complexes was simulated by Hyperchem. The results indicate that there are hydrogen bond or ionic bond between functional monomer and template molecule in acetonitrile solution. The MIP made in cold-initiated photo-polymerization has higher separation performance than that in the therm-initiated polymerization. The separation of the isomers CN and cinchonidine (CD) can be successfully obtained when its separate factor α reaches 1.82. Scatchard analysis suggests that the MIP recognizing CN with two classes of binding sites. The partition coefficient K _{d, 1} and apparent maximum number n _{max, 1} of binding sites with high affinity are 131.43 μmol/L and 58.90 μmol/g, respectively, while K _{d, 2} and n _{max, 2} of binding sites with low affinity are 2.32 mmol/L and 169.08 mmol/g, respectively. Foundation item: Project(2004035085) supported by the Postdoctoral Science Foundation of China; project(04JJ3080) supported by the Natural Science Foundation of Hunan Province     

铜回转式阳极炉燃煤工艺技术的探讨

介绍了云南铜业股份有限公司利用新建的2台350t回转式阳极炉进行以粉煤作为燃料的工艺技术开发情况,提出了铜火法精炼回转式阳极炉用粉煤作燃料在工艺和工程施工中存在的问题和难点,对比分析了燃煤回转式阳极炉具有的优势。     

特殊油井生产动态监测方法研究

针对低产量三相流动生产井，提出了新的产出剖面测井仪器组合。基于流动实验研究结果对其测井资料解释提出了新的方法。     

非线性系统平稳分岐解镇定的简化原理

研究了一类具有线性不可控模态的非线性系统平稳分岐解的镇定问题.假定系统参数不可测量.基于不变流形理论,从原非线性系统导出了一个一维的简化方程.从简化方程的性质导出了原系统能分岐镇定的一些充分和必要条件.并举例说明了此方法的有效性.