Periodic traveling curved fronts in reaction-diffusion equation with bistable time-periodic nonlinearity

This paper is concerned with the existence and stability of periodic traveling curved fronts for reaction-diffusion equations with time-periodic bistable nonlinearity in two-dimensional space. By constructing supersolution and subsolution, we prove the existence of periodic traveling wave fronts. Furthermore, we show that the front is globally stable.     

偏硼酸钡低温相晶体在高压下的电学性质与相变

 在金刚石压砧装置上，采用电容和电阻测量方法研究了偏硼酸钡低温相晶体（β-BaB₂O₄）在室温下和16 GPa内的电容、电阻与压力的关系。实验结果表明，它的电容在2.1、4.6、6.4、8、9.5、10.7 GPa左右都有一个突变。这说明β-BaB₂O₄内部的结构状态在这些压力下都发生了变化，可能发生了相变。还发现β-BaB₂O₄样品在较高压力下已发生了非晶化转变，而且是不可逆的，在卸压后被保留下来。这个非晶化转变的压力大约在11~12 GPa。     

Impulsive synchronization seeking in general complex delayed dynamical networks

The present paper investigates the issues of impulsive synchronization seeking in general complex delayed dynamical networks with nonsymmetrical coupling. By establishing the extended Halanay differential inequality on impulsive delayed dynamical systems, some simple yet generic sufficient conditions for global exponential synchronization of the impulsive controlled delayed dynamical networks are derived analytically. Compared with some existing works, the distinctive features of these sufficient conditions indicate two aspects: on the one hand, these sufficient conditions can provide an effective impulsive control scheme to synchronize an arbitrary given delayed dynamical network to a desired synchronization state even if the original given network may be asynchronous itself. On the other hand, the controlled synchronization state can be selected as a weighted average of all the states in the network for the purpose of practical control strategy, which reveals the contributions and influences of various nodes in synchronization seeking processes of the dynamical networks. It is shown that impulses play an important role in making the delayed dynamical networks globally exponentially synchronized. Furthermore, the results are applied to a typical nearest-neighbor unidirectional time-delay coupled networks composed of chaotic FHN neuron oscillators, and numerical simulations are given to demonstrate the effectiveness of the proposed control methodology.     

带非卷积位相的粗糙核振荡奇异积分算子的加权L^p估计

文研究一类位相较多项式更一般的振荡奇异积分算子．在积分核Ω∈Llog^＋L（S^n-1）的条件下,建立了该类算子在加权Lp空间的有界性．     

抗坏血酸基体改进剂平台石墨炉原子吸收光谱法测定蚝油中的铅

本实验建立了以抗坏血酸为基体改进剂测定蚝油中铅的方法。研究了多种基体改进剂消除蚝油基体对测铅的干扰，方法的相对标准偏差为４．９％，回收率为９４％－９６％，检出限为１．５ｎｇ／ｍＬ。本方法可用于蚝油、贻贝油等调味品中铅含量的测定。     

获得高质量Moire条纹信号的一种新方法

在细栅距的幅光栅系统中，衍射效应是很明显的，其能量约占总能量的１０～４０％左右，这种衍射光是造成Ｍｏｉｒｅ光电信号对比度不好和正弦性差的根本原因。本文分析了衍射光栅副±１级Ｍｏｉｒｅ条纹的位相关系与光栅副间隙等因素的关系，提出了利用±１级Ｍｏｉｒｅ条纹来获得高质量Ｍｏｉｒｅ条纹信号，实际应用，效果良好。     

光学玻璃加工破坏层研究及粗磨、精磨、抛光工序加工余量的合理匹配

本文通过用五种散粒磨料（碳化硅）、五种固着磨料（金刚石）对八大类常用光学玻璃进行加工，用扫瞄电子显微镜观察其表面形貌，用抛测法测出其破坏层深度，得出一系列破坏层的深度数值，从而找出破坏层与磨料之问的函数关系。以破坏层的绝对深度为依据，得出光学加工中精磨、抛光工序的加工余量的合理匹配值。     

Composite meromorphic functions and normal families

In this paper, we study the normality of families of meromorphic functions. We prove the result: Let α(z) be a holomorphic function and \({\mathcal{F}}\) a family of meromorphic functions in a domain D, P(z) be a polynomial of degree at least 3. If P ○ f(z) and P ○ g(z) share α(z) IM for each pair \({f(z),g(z)\in \mathcal{F}}\) and one of the following conditions holds: (1) P(z) ? α(z ₀) has at least three distinct zeros for any \({z_{0}\in D}\); (2) There exists \({z_{0}\in D}\) such that P(z) ? α(z ₀) has at most two distinct zeros and α(z) is nonconstant. Assume that β ₀ is a zero of P(z) ? α(z ₀) with multiplicity p and that the multiplicities l and k of zeros of f(z) ? β ₀ and α(z) ? α(z ₀) at z ₀, respectively, satisfy k ≠ lp, for all \({f(z)\in\mathcal{F}}\). Then \({\mathcal{F}}\) is normal in D. In particular, the result is a kind of generalization of the famous Montel criterion.     

Analysis and modeling of resistive switching mechanisms oriented to resistive random-access memory

With the progress of the semiconductor industry,the resistive random-access memory(RAM) has drawn increasing attention.The discovery of the memristor has brought much attention to this study.Research has focused on the resistive switching characteristics of different materials and the analysis of resistive switching mechanisms.We discuss the resistive switching mechanisms of different materials in this paper and analyze the differences of those mechanisms from the view point of circuitry to establish their respective circuit models.Finally,simulations are presented.We give the prospect of using different materials in resistive RAM on account of their resistive switching mechanisms,which are applied to explain their resistive switchings.