聚乳酸类医用生物降解材料的研究进展

聚乳酸由于其突出的优点如生物相容性好、降解产物对人体无毒而倍受重视,并且在生物医学领域的应用中获得了很好的效果。本文对聚乳酸的合成及在医学方面的应用作了总结和评述,并对其在生物医学领域的应用前景作了进一步展望。     

数学物理方程中的通解问题

通过例证说明,通解法对于偏微分方程而言,其适用范围要比通常认为的大.并表明,只要适当变通,行波法就可用于有界情况.     

基于ARX模型的压电智能结构振动预测控制

采用预测控制法对压电智能结构的振动主动控制进行了实验研究，通过实验方法建立了系统的ARX模型，并在此基础上设计了预测控制器对结构进行振动主动控制。实验结果验证了该方法在压电智能结构振动主动控制中的可行性和有效性。     

高速并行调制解调器中差错控制方法

本文简单介绍了适合高速并行调制解调器中差错控制的Reed-Solomon编码，提出了适合DSP软件实现的一整套的RS码的编码、译码实用方法，并对该编、译码法采用数字信号处理器TMS320C5410b进行仿真，对其性能与传统方法进行了对比。     

Monte Carlo Hamiltonian: Linear Potentials

We further study the validity of the Monte Carlo Hamiltonian method. The advantage of the method,in comparison with the standard Monte Carlo Lagrangian approach, is its capability to study the excited states. Weconsider two quantum mechanical models: a symmetric one V(x) = |x|/2; and an asymmetric one V(x) = ∞, forx ＜ 0 and V(x) = x, for x ≥ 0. The results for the spectrum, wave functions and thermodynamical observables are inagreement with the analytical or Runge-Kutta calculations.     

鲁棒稳定性分析的值映射与参数化方法

本文运用值映射与参数化的方法研究了鲁棒D稳定性问题。文中给出了主要结果——参数空间鲁棒分析的边界定理,作为该结果的应用,一些现代鲁棒分析的知名结果,例如多项式族的稜边定理,Kharitonov定理和菱形定理都被简洁地证明出来;给出了一种判定双参数多项式族D稳定的新方法。用该方法可以方便地确定H稳定多项式按一定摄动模式(区间方式和菱形方形)的最大摄动界。     

用干涉方法测量薄膜应力

基于基片弯曲法和牛顿环的基本原理,使用He-Ne激光器、扩束镜、凸透镜和带分光镜的移测显微镜,搭建了薄膜应力测量装置.采用直流溅射法制备了厚度为30~144 nm的银薄膜,衬底采用厚度为0.15 mm、直径为18 mm的圆形玻璃片.实验发现,薄膜厚度对银薄膜的内应力有显著的影响,在薄膜厚度很小时,随着薄膜厚度的增加,应力迅速增大,达到最大值后,随着厚度的继续增加,薄膜应力下降较快并趋于稳定值.     

Spectral Representation Theory for Dielectric Behavior of Nonspherical Cell Suspensions

Recent experiments revealed that the dielectric dispersion spectrum of fission yeast cells in a suspension was mainly composed of two sub-dispersions. The low-frequency sub-dispersion depended on the cell length, while the high-frequency one was independent of it. The cell shape effect was simulated by an ellipsoidal cell model but the comparison between theory and experiment was far from being satisfactory. Prompted by the discrepancy, we proposed the use of spectral representation to analyze more realistic cell models. We adopted a shell-spheroidal model to analyze the effects of the cell membrane. It is found that the dielectric property of the cell membrane has only a minor effect on the dispersion magnitude ratio and the characteristic frequency ratio. We further included the effect of rotation of dipole induced by an external electric field, and solved the dipole-rotation spheroidal model in the spectral representation.Good agreement between theory and experiment has been obtained.     

枸橼酸莫沙必利的合成

分别以邻羟基对氨基苯甲醇钠，对氟苯甲醛，邻苯二甲酰亚胺为起始原料，制得3个中间体，用其中2个中间体经偶合，环化后与第3个中间体反应，再经成盐制得产品，其摩尔总收率为31．5％。     

四阶半线性椭圆型积分微分方程的奇摄动

本文研究了一个四阶椭圆型积分微分方程的奇摄动问题。证明了相应的比较定理并得到了解的一致有效的渐近展开式。