双-锌卟啉对DABCO分子识别的立体构象及其热力学研究

合成了系列不同长度以柔性侧链相连的p/p型双-锌卟啉配合物,用¹H NMR和UV-Vis研究了不同温度下该系列配合物与刚性双齿配体DABCO(1,4-二氮杂双环)的轴向配位反应,考察了侧链长度对双-锌卟啉与配体的分子识别能力影响。结果表明,主体分子双-锌卟啉可以对客体分子BABCO进行分子识别,合适长度的柔韧烷氧链可以调节主体分子的构象,使DABCO嵌入双卟啉两个卟啉环间空位中,形成锌卟啉-DABCO-锌卟啉三元夹心式配合物构象。探讨了配位反应中立体构象的变化过程,并测定了热力学参数。     

不可压超弹性材料中的空穴分叉

研究了一种不可压Valanis-Landel材料超弹性球体在表面死载荷作用下的球形空穴的分叉问题。给出了空穴分叉问题的解析解,讨论了空穴生成时的应力间断和应力集中问题。通过能量比较判断了解的稳定性,并分析了球体中预存微孔的增长情况。     

Neutron Halos in the Excited States of Spherical Nuclei Near the β-Stable Line

The newly discovered neutron halos in the excited states of nuclei ¹²B, ¹³C, and ²⁰⁹Pb are studied by the relativistic mean-field theory. The calculated binding energies are very close to the experimental ones. The experimentally extracted root-mean-square radii of the last neutron with different occupations in nuclei are well reproduced by calculations. New candidates for the neutron halos in excited states are predicted and are useful for further search of neutron halos in the excited states of stable nuclei.     

横观各向同性多孔超弹性矩形板的单向拉伸

利用横观各向同性超弹性材料的广义neo-Hookean应变能函数研究了含有多个微孔的超弹性矩形板在单向拉伸作用下的有限变形和受力分析.给出了含有某种对称性分布的多个微孔的矩形板的变形模式,通过求解该变形模式满足的微分方程,将它用两个参数表示出来.可应用最小势能原理导出变分近似解,从而得到矩形板的变形和应力分布的解析解.分析了板中微孔的增长及微孔边缘应力的分布情况,讨论了板的各向异性程度及微孔的大小和孔间距离的影响,得到了单个、三个及五个微孔板中微孔的增长变形和孔边应力分布的一些基本规律规律,并进行了相互比较.     

Alpha Decay,Shell Structure,and New Elements

We systematically analyze the experimental data of alpha decay in even-even heavy nuclei far from stability and find that the Geiger-Nuttall law brea~s for an isotopic chain when its neutron number is across a marc number or there is a deformed subshell. This break can be used to identify new magic numbers of superheavy nuclei. It is also discovered that there is a new linear relation between the logarithm of half-life and the reciprocal of the square root of decay energy for N = 126 and N = 152 isotones. It could be a new law of alpha decay for nuclei with magic neutron numbers but the physics behind it is to be explored. The significance of these researches for the search of new elements is discussed.     

含有模糊决策的线性分布式多目标规划

针对实际问题中决策变量通常是模糊的情况,讨论具有块角结构的含有模糊决策的线性分式多目标规划模型。使用α－水平集,建立了对应的α－多目标规划模型。为解决这类问题,设计了基于模糊模拟的遗传算法。数值例子表明,遗传算法很好地解决了这个问题。     

一种确定加速车道长度的概率统计模型

加速车道有利于次要道路上的车流平顺地汇入高速公路的车流 ,加速车道长度的确定是加速车道设计的核心内容。本文针对加速车道车流的运行特性 ,从概率统计角度研究了加速车道上车辆汇入高速公路车流的概率 ,并在此基础上得到了一种用于确定加速车道长度的实用模型     

单力矩器大角速率动调陀螺仪力矩再平衡回路的分析与综合

针对仅有一个力矩器的大角速率动调陀螺仪,力矩器线圈必须通以与陀螺仪自转角速率同频率变化的交变电流的特点,分析了采用合成施矩方式的力矩再平衡回路的工作原理。根据系统要求,对放大校正环节进行了设计。通过系统仿真及实例,验证了仿真模型的可信性及设计的合理性。     

用格子Boltzmann模型模拟非等温流场

根据微观和宏观之间的质量、动量、能量守恒准则和在原格子Boltzmann模型基础上,建立了几个新的格子Boltzmann模型,使得在外力场中的格子Boltzmann模型得到进一步完善.通过还原宏观流体力学方程,捕捉到了浮力强迫系数与Grashof数之间的关系.所得动量方程和Navier Stokes方程相比,在黏性输运项上有明显的改进,说明黏性应力不但与流体的速度梯度和流体的压缩性有关,而且还与非定常的内能梯度和动量通量有关.该模型对非等温流场的数值结果证明了其具有很好的数值稳定性和适用性. 关键词： Boltzmann模型 平衡分布函数 流体力学方程     

Determination of Optical Properties of Turbid Media from Spatially Resolved Diffuse Reflectance by Neural Network

A backpropagation (BP) network is applied to the inversion of spatially resolved diffuse reflectance from turbid media and then to determine its optical properties. A standard BP network may be trapped to the local minimum. A BP network with variable momentum and variable leaning rate can reduce this effect. After being trained, this network will produce reduced scattering coefficients and absorption coefficients when the spatially resolved diffuse reflectance are fed to its input.