Modulation of Electrochemical Oscillations by Specific Adsorption of Cl^— during the Electrooxidation of Methanol on Pt Electrode

Potential oscillation during the electrocatalytic oxidation of methanol can be modulated by the specific adsorption of Cl^- on the platinum electrode, which suppresses the electrocatalytic oxidation of methanol, and makes the cross cycle in the cyclic voltammogram become smaller and finally disappear with the increase of Cl^- concentration. The method is also applicable to the electrocatalytic oxidation of other small organic molecules.     

光电效应中饱和光电流与入射光频率的关系研究

指出了关于饱和光电流随入射光频率变化的几种不正确的认识。给出了光强一定时饱和光电流随入射光频率变化的正确规律并作了解释。     

一种光CDMA频域的二次方一致性码

在二次方一致性的基础上,构造了一种容量大、自相关和互相关特性好的码族研究表明,采用这个码族的光码分多址(OpticalCDMA)系统比波分复用(WDM)系统拥有大得多的用户数而且这个码族很适合于异步和多比特率接入的光码分多址系统据我们了解,这种码字用于在光码分多址非相干频域编制中为首次被提出.     

EXISTENCE AND GLOBAL ATTRACTIVITY OF POSITIVE SOLUTIONS OF A NONAUTONOMOUS LOGISTIC TYPE MODEL WITH QUADRATIC NONLINEARITY

Consider the nonautonomous logistic modelwhere {pn} is a sequence of positive real numbers, {kn} is a sequence of non-negative integers satisfying We obtainnew sufficient conditions for the attractivity of the equilibrium x = x of the model. Our results improve ones which were established by Gapalsamy and Ladas recently, and solve some research projects posed by Kocic and Ladas in [7].     

Sufficient Conditions for the Oscillation of Non-autonomous Difference Equations

Abstract In this paper, we obtain sufficient conditions for the oscillation of the non-autonomous differenceequations x(n 1)-x(n) sum from i=1 to m p_i(n)x(n-r_i(n))=0,which are the discrete analog of the delay differential equations considered in[1].     

Multiple periodic oscillations in a nonlinear suspension bridge system

In this paper, we study periodic oscillations in a suspension bridge system governed by the coupled nonlinear wave and beam equations describing oscillations in the supporting cable and roadbed under periodic external forces. By applying a variational reduction method, it is proved that the suspension bridge system has at least three periodic oscillations.     

基于电流和相位差的超声换能器频率自动跟踪

为了提高超声换能器频率跟踪的稳定性,通过对最小电流法和相位差法的原理和应用范围进行分析,提出了基于最小电流和相位差法相结合的并联谐振频率跟踪策略,该策略主要思想是将最小电流法运用于换能器空载阶段,相位差法运用于带载阶段,并且带载时的起始驱动频率取为空载阶段跟踪到的并联谐振频率。由此对最小电流法和相位差法这两种跟踪方法进行取长补短。基于该跟踪策略对换能器在不同负载下进行了实验,结果表明该策略可以快速地跟踪到换能器的并联谐振频率,并且工作稳定。     

嵌入式频率特性分析仪的设计及实现

研究设计基于PC104和FPGA的嵌入式频率特性分析仪。该分析仪采用虚拟仪器的概念,以PC104 CPU为主控单元,通过FPGA控制D/A、A/D芯片时序,输出全频率范围内的正弦波并采样存储系统激励信号及输出响应,最后通过CPU算法处理得到系统频率特性。实验结果表明：该仪器人机界面友好,测量速度快,测试波形与理论计算波形能较好吻合。