模拟回火马尔可夫链蒙特卡罗全波形分析方法

针对传统的全波形分析方法不能快速自动处理全波形数据的缺点,提出了一种模拟回火马尔可夫链蒙特卡罗全波形分析法,用于求解全波形数据中的波峰数和峰值位置等参量.该方法采用Metropolis更新策略求解波峰数量和噪声两个参量,以达到快速求解的目的;而峰值位置和波峰幅值则采用改进的模拟回火策略求解,通过添加的主动干预回火步骤实现对参量更新过程的有效探测,以满足对速度或运算收敛性的要求.模拟回火马尔可夫链蒙特卡罗全波形分析方法以马尔可夫算法为基础,仍保持马氏链的收敛性,从而保证本方法具有良好的鲁棒性,实现对全波形数据的自动化处理.     

Optimizing the Triple‐Potential Waveform for the Pulsed Amperometric Detection of Streptomycin

Abstract

A triple‐potential waveform used for amperometric detection of streptomycin (STP) is investigated. The mobile phase is an aqueous solution of 75 mM phosphoric acid. Waveform parameters are optimized to maximize the signal‐to‐noise ratio (S/N). The potentials of the waveform are designated E1, E2, and E3, and potentials are maintained for time periods t1, t2, and t3. Unlike the normal triple‐potential waveform, the cleaning function is accomplished at negative potential instead of positive potential in our triple‐potential waveform. The detection limit of STP is <0.04 µg mL^?1 (S/N=3). The linearity of STP ranges from 0.1 to 5 µg mL^?1 (r=0.9986). RSD (n=30) of the peak area of STP is 5.8%. The triple‐potential waveform shows low detection limits and long‐term reproducibility.     

一种新的局部时间积分的区域分解波形松弛算法

提出一种新的区域分解波形松弛算法, 使得可以在不同的子域采用不同的时间步长来并行求解线性抛物方程的初边值问题. 与传统的区域分解波形松弛算法相比, 该算法可以通过预条件子来加快收敛速度, 并且对内存的需求大大降低. 给出了局部时间步长一种具体的实现方法, 证明了离散解的存在唯一性, 并在时间连续水平分析了预条件系统. 数值实验显示了新算法的有效性.     

A new tracking error detection method using amplitude difference detection for signal waveform modulation multi-level discs

The sub-land/sub-pit affects the characteristic of the tracking error signal which is generated by the conventional differential phase detection (DPD) method in the signal waveform modulation multi-level (SWML) read-only disc. To solve this problem, this paper proposes a new tracking error detection method using amplitude difference. Based on the diffraction theory, the amplitude difference is proportional to the tracking error and is feasible to be used for obtaining the off-track information. The experimental system of the amplitude difference detection method is developed. The experimental results show that the tracking error signal derived from the new method has better performance in uniformity and signal-to-noise ratio than that derived from the conventional DPD method in the SWML read-only disc.     

传输式大功率电火花震源在浅水中及井中的压力波形及频谱分析

本文通过对传输式电火花震源在浅水中及井中所产生压力波形的分析,确定了压力波峰值与放电电极距离的关系,获得了压力波与放电能量、静水压、测量距离 之间的基本关系。并对试验结果进行了分析。     

Discretized Multisplitting AOR Waveform Relaxation Algorithms for Initial Value Problem of Systems of ODEs

1.IntroductionInthedevelopmentofnewelectricalcircuits,thesimulationofthebehaviourofthecircuithasbecomeanessentialtoolforelectricalengineers.Fromthelayoutofthecircuitanonlinearsystemofordinarydifferentialequationsisgeneratedwhichdescribesthedynamicalbehaviourofthecircuit.Inthesimulationofverylargescaleintegrated(VLSI)circuitsthedimensionofthesystemofODEscanbecomeverylarge.Moreoversincethesystemisstiff,solvingthesesystemsisaverycomputionallyintensivetaskandtheuseofsupercomputersbecomesin-evit…     

Complex Behavior in an Integrate-and-Fire Neuron Model Based on Small World Networks

Based on our previously pulse-coupled integrate-and-fire neuron model in small world networks, we investigate the complex behavior of electroencephalographic （EEG）-like activities produced by such a model. We find EEG-like activities have obvious chaotic characteristics. We also analyze the complex behaviors of EEG-like signals,such as spectral analysis, reconstruction of the phase space, the correlation dimension, and so on.     

WAVEFORM RELAXATION METHODS AND ACCURACY INCREASE

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高场不对称波形离子迁移谱快速检测水样中苯含量

建立了高场不对称波形离子迁移谱(FAIMS)检测水中苯含量的分析方法。研究了不同分离电压(Dispersion voltage,DV)下的苯标准谱图,获得用于苯识别的非线性函数二阶α2及四阶α4系数值分别为-3.8×10-5Td-2和5.1×10-8Td-4;通过平衡灵敏度与分离度,得到用于苯识别的最佳分离电压为800 V;通过不同质量浓度(0.08~0.64 mg/L)的苯样品与苯离子信号强度的关系,确定高场不对称波形离子迁移谱(FAIMS)对水中苯的检出限为0.89μg/L,远优于国家饮用水中苯浓度的限值10μg/L。本研究为水中苯检测提供了一种快速、高灵敏的方法。     

Effect of Linewidth Enhancement Factor on Doppler Beat Waveform Obtained from a Self-Mixing Laser Diode

The asymmetry and fringe inclination of the sawtooth-like waveform observed in the self-mixing signal obtained from a semiconductor laser with optical feedback enable the direction discrimination of line-of-sight motion of external target surfaces. We investigated the effects of linewidth enhancement factor and feedback strength on the asymmetry and the direction of fringe inclination of the signal by numerical simulations. For the first time, we show that direction of the fringe inclination is determined not only by the direction of the target motion but also by the value of the linewidth enhancement factor.