Voltammetric determination of catechin using single-walled carbon nanotubes/poly(hydroxymethylated-3,4-ethylenedioxythiophene) composite modified electrode

Ionics - A simple, sensitive, and reliable carboxylic group functionalized single-walled carbon nanotubes (f-SWCNTs)/poly(hydroxymethylated-3,4-ethylenedioxythiophene) (PEDOTM) modified glassy...     

DRC-MME高级参数模型直通标定实验的自由度分析

在椭偏测量中,采用直通式标定方法准确标定出系统模型参数对于样品的精确测量至关重要.由于双旋转补偿器式Mueller矩阵椭偏仪(DRC-MME)高级参数模型复杂,参数数量较多,且部分高级参数之间存在相互级联和耦合,为保证标定结果的准确性,实验中各个参数之间的独立性关系需要被检验.针对这一问题,使用奇异值分解、泡利矩阵和其...     

基于尾迹面法的气动力积分技术研究

基于Roe的空间离散格式,以绕ONERAM6、LANN机翼流场为算例,分别以Euler和N-S方程为主控方程,对尾迹面法气动力积分技术进行初步探讨,重点讨论了尾迹面位置对气动力的影响。引入不同尾迹插值方法,研究了不同插值方法对气动力积分结果的影响,为气动力的精确性计算提供了气动分析平台。研究结果表明:当尾迹面的位置处于机翼后0.5到1.5倍平均气动弦范围内时,此方法具备较好的气动力积分精度;与中心插值相比,基于格心距离加权的流动参数插值有更高的积分精度。     

Numerical computation of connecting orbits on a manifold

In this paper we propose a numerical method for approximating connecting orbits on a manifold and its bifurcation parameters. First we extend the standard nondegeneracy condition to the connecting orbits on a manifold. Then we construct a well-posed system such that the nondegenerate connecting orbit pair on a manifold is its regular solution. We use a difference method to discretize the ODE part in this well-posed system and we find that the numerical solutions still remain on the same manifold. We also set up a modified projection boundary condition to truncate connecting orbits on a manifold onto a finite interval. Then we prove the existence of truncated approximate connecting orbit pairs and derive error estimates. Finally, we carry out some numerical experiments to illustrate the theoretical estimates.     

Robust stabilization of delayed nonholonomic systems with strong nonlinear drifts

This paper presents a control strategy for stabilization of nonholonomic control systems with strongly nonlinear uncertainties and time delay. By applying a novel Lyapunov functional, discontinuous transformation and dynamic feedback approach, robust nonlinear state feedback switching controllers are designed, which can guarantee the stabilization of closed loop systems. The proposed method proves to be effective by a simulation example.     

Subgeometric ergodicity for continuous-time Markov chains

In this paper, subgeometric ergodicity is investigated for continuous-time Markov chains. Several equivalent conditions, based on the first hitting time or the drift function, are derived as the main theorem. In its corollaries, practical drift criteria are given for ?-ergodicity and computable bounds on subgeometric convergence rates are obtained for stochastically monotone Markov chains. These results are illustrated by examples.     

C_(60)薄膜的离化团簇束沉积及离子掺杂

用离化团簇束（ＩＣＢ）沉积法在石英玻璃和云母衬底上形成了Ｃ６０薄膜，ＸＲＤ测试表明膜呈多晶结构，原位电阻测试表明膜的室温电阻率超过１０４Ωｃｍ，具有负的电阻温度系数．用８０ｋｅＶＰ＋，ＢＢｒ３＋，Ａｒ＋和Ｈｅ＋对Ｃ６０膜作剂量范围为０～１０１６ｃｍ－２的离子注入，Ｃ６０膜的电阻率随注入剂量增加而急剧下降，磷注入具有ｎ型掺杂作用，离子与Ｃ６０分子的相互作用导致Ｃ６０分子分裂，引起薄膜表面非晶化．     

渐进多焦点眼用镜片的子午线设计研究

介绍渐进多焦点眼用镜片的构造,论述镜片的设计思想,阐述渐进多焦点眼用镜片子午线设计的基本原理,构建子午线多项式,给出子午线设计需满足的准则.在子午线设计的基础上,设计渐进多焦点眼用镜片等屈光度轮廓线,确定镜片面形,并求出镜片平均球面度与像散.比较3种不同子午线设计的渐进多焦点眼用镜片,并进行实际加工与检测.研究结果表明,子午线设计是渐进多焦点眼用镜片设计的关键之一,不同的子午线屈光度分布,对应的渐进多焦点眼用镜片的球面度、像散以及畸变等差别较大.依据实际设计与检测结果,给出适用于不同个性化需求的渐进多焦点眼用镜片子午线屈光度分布的规律.