耦合反应扩散体系中分布式延迟对图灵斑图的影响

在许多信息传递系统中都存在延迟现象,相关研究表明,耦合振子系统中的延迟作用能导致振死、多节律混沌、空间斑图和波等现象,其中多数现象已经得到的实验验证．图灵斑图与生物成型素具有潜在的联系,使其在理论和实验方面得到了多方面的研究．Barrio等发现图灵体系间的耦合作用可以得到与生物界相似的复杂斑图．Yang等也在耦合体系中发现了一系列新型图灵斑图．     

电化学时空斑图

时空斑图广泛存在于反应-输运非平衡态体系,近年来电化学体系中时空斑图的形成开始受到广泛关注.从行波到Turing稳态结构在电化学体系都有发现和研究,这大大促进了电化学动力学的理论发展.理论模型已由最初的反应-扩散模型逐渐演化和完善成为电化学反应-电迁移模型,促使实验与理论研究的进一步开展.随着时空识别电化学技术的应用,...     

反应-扩散斑图反应器*

本文综述了在反应-扩散斑图研究中反应器的进展情况。直到20世纪80年代,人们主要在培养皿中研究封闭体系的化学波。为了研究体系在远离平衡态条件下的复杂时空动力学行为,近二十年来人们设计出许多新颖的空间开放反应器(continuously fed unstirred reactor,CFUR)如单边进料反应器(one side fed reactor,OSFR)、双边进料反应器、圆盘形凝胶、圆环形凝胶反应器以及Couette反应器等。反应介质主要为各种凝胶、微孔膜、离子交换树脂以及中孔玻璃。空间开放反应器的设计和发展极大地促进了化学斑图动力学的发展。同时讨论了反应-扩散斑图反应器结构设计遇到的困难如气泡和三维效应,并且对反应器设计与斑图研究未来发展方向进行了探讨。     

硫化学反应体系中的振荡与斑图形成

硫化学非线性反应体系是非线性化学的一个重要部分,在均相和反应扩散介质中均表现复杂自组织现象,尤其该类体系在前沿波作用、迷宫波及倍增分裂波研究和近几年斑图系统设计的突破起着关键作用。根据参与的物种数量将硫化学反应体系分为简单的两组分和三组分反应体系两大类。本文重点介绍了近三十年来这两类硫化学振荡器和反应-扩散斑图的研究进展,简述了该类反应体系在生物及其软物质领域的应用。最后,对硫化学振荡体系研究中存在的问题进行了探讨,并对今后的研究方向进行了展望。     

硫化物在铂电极上电氧化时空动力学的模型模拟和分析(英文)

根据铂电极上硫化物电催化氧化的反应机理,本文提取动力学模型并利用数值模拟研究了N型负微分阻抗(N-NDR)振荡区域的电极表面时空反应动力学.在均相体系模拟中观察到电流简单振荡和复杂振荡,其来源于双电层电势自催化与传质限制和毒化物种吸附负反馈的相互耦合.为了更接近于真实体系,在模型中考虑了平行和垂直于电极表面两个方向的传质过程.模拟结果发现了与实验现象具有相同演化行为的复杂斑图,如行波和闪烁波;同时在传质耦合体系模拟中观察到双电层电势双臂螺旋波.本研究工作促进对电化学体系时空斑图的理解和预测.     

基于海水淡化的生物电化学脱盐技术研究进展及应用前景

生物电化学脱盐技术是一种在生物电化学基础上发展起来的微生物脱盐池与传统海水淡化技术的耦合,为海水淡化提供了一种全新的低能耗的方法。本文综述了自2009年微生物脱盐池问世以来的研究进展。简要介绍了生物电化学脱盐的基本原理和系统评价参数;比较了生物电化学脱盐系统构型对脱盐效率的影响;探讨了生物电化学脱盐过程中的限制因素;展望了生物电化学脱盐技术在海水淡化方面的应用前景。     

基于规则空间模型的高中生电化学概念理解的认知诊断

以规则空间模型为指导，以电化学基础内容为载体，从知识内容属性和过程属性2个维度构建电化学基础认知属性模型，开展化学学科的认知诊断研究。研究发现电化学基础认知属性模型合理；规则空间模型在电化学基础概念理解中得到了成功的应用；81%的被试群体可归入18种理想反应模型，可有效指导个体和班级开展补救性教学。     

一些电化学交流阻抗复数平面图旋转的物理意义

本文讨论了电化学交流阻抗图中图形旋转的物理意义.电化学体系等效电路中的电容基本上属复数电容,由此推导出在这个假设下的阻抗极坐标公式,及其参数的数学表达式.实际上此表达式与很多电化学体系的实际阻抗谱相符,如:实际测量的理想极化电极的阻抗图并不是平行于虚轴的一条直线,而是其与实轴的交点顺时钟旋转了α角的直线,这时,即双层电容的耗散角;与RC并联电路有关的半圆阻抗图几乎都有同一方向的α角旋转,其值等于相关电容的耗散角.若明确了旋转的物理意义,由电化学阻抗谱拟合得到的参数均可表征体系的性质,这对于寻求某些特殊性能的电池体系将是有用的.     

在抗坏血酸存在下用L-赖氨酸修饰玻碳电极测定多巴胺

采用电化学氧化法制备了L-广赖氮酸单分子层修饰玻碳电极,研究了多巴胺（DA）和抗坏血酸（AA）在该电极上的电化学行为。结果表明,L-广赖氨酸单分子层修饰玻碳电极不仅能改善多巴胺和抗坏血酸的电化学行为,而且能将多巴胺和抗坏血酸二者在裸电极上的完全重叠的单氧化峰分开成为两个完全独立的氧化峰,循环伏安（CV）图上峰间距为507mV,差分脉冲伏安（DPV）图上峰间距为460mV,由此可实现在AA的共存下对样品中的DA进行选择性测定。     

Fe-H2SO4体系中外电阻诱发电化学振荡的实验研究

电化学振荡是电化学体系在远离平衡条件下出现的电流或电压随时间周期变化的现象,由于它可以作为系统复杂动力学行为的典型范例,因而引起了人们极大的兴趣。目前的相关研究不仅包括发现新的振荡体系^[1-4]以及明确产生振荡的内部电化学反应机制^[5-8]、还涉及探索电阻^[5,9-13]、噪音^[16,17]等外部因素的耦合作用,特别是对于电阻耦合作用的研究近年来颇受关注。     

Fronts, Waves, and Stationary Patterns in Electrochemical Systems In the appendix we list the minimal equations (prototype equations) that describe the phenomena of self-organization discussed in the individual sections

Oscillatory behavior has been observed for almost all electrochemical reactions in a certain, although sometimes small, range of external parameters. Only in the past ten years has it been possible, however, to find a common explanation for the occurrence of these temporal self-organization phenomena of chemically completely different electrochemical reactions. The breakthrough was achieved because new methods and concepts, which had been developed in nonlinear dynamics to describe the spontaneous formation of order in various disciplines, could be applied. This development in turn was only possible because the underlying laws are universal at a certain abstract level. Oscillations are only one possible manifestation of nonlinear behavior. Examples of other features that are often closely associated with temporal instabilities are spatial structures and waves. Initiated by the theoretical progress and the development of new experimental techniques, spatial pattern formation in electrochemical systems has been targeted for investigations in the past few years. Based on these investigations, it can be predicted under which conditions temporal or spatial pattern formation can be expected. Furthermore, the possibility of predicting the occurrence of instabilities indicates that it might be feasible to exploit nonlinear effects to increase, for example, the yield of electrocatalytic reactions. Here we discuss physicochemical mechanisms that lead to pattern formation in electrochemical systems. At the same time, we stress the generic principles that are responsible for self-structuring processes in many chemical and biological systems.     

基于多肽的电化学传感器在蛋白质检测中应用的研究进展

生物体内的细胞通常会分泌各种各样的蛋白质,这些蛋白质在生物体中发挥着重要作用,尤其是可被用于诊断各种疾病的发生和发展。多肽具有良好选择性、空间适应能力和识别灵活的特点,可与不同类型的蛋白分子形成非共价键,用于蛋白质的生物检测。将多肽与电化学生物传感器结合用于蛋白质的广谱检测具有良好的发展前景。本文介绍了多肽修饰的电化学传感器在不同蛋白质检测方面的研究进展,分析了待测蛋白质的不同对多肽修饰的电化学传感器分类的影响及其优缺点,提出了基于多肽的电化学传感器在不同蛋白质检测中存在的问题,并展望了其未来发展。     

Nanoconfinement Effects: Glucose Oxidase Reaction Kinetics in Nanofluidics

Size‐tunable nanofluidic devices coupled to an electrochemical detector have been designed and then used to study glucose oxidase (GOx) reaction kinetics confined in nanospaces. The devices are fabricated via a photochemical decomposition reaction, which forms nanochannels covered with carboxyl groups. The generated carboxyl groups enable us to chemically pattern biological molecules on the polymer surfaces via covalent bonding. With this approach, the activity of the immobilized biological molecules confined in nanospaces with different sizes has been investigated. GOx species are chemically immobilized on the surface of the nanochannels, catalyzing the oxidation of substrate glucose as it flows through the channels. The enzyme reaction product, hydrogen peroxide, passing through the nanochannels, reaches an electrochemical detector, giving rise to an increase in anodic current. This steady‐state electrochemical current, which responds to various glucose concentrations, can be used to evaluate the GOx activity under confinement conditions. The results show significant nanoconfinement effects that are dependent on the channel size where the reaction occurs, demonstrating the importance of spatial confinement on the GOx reaction kinetics. The present approach provides an effective method for the study of enzyme activity and other bioassay systems, such as cell assays, drug discovery, and clinical diagnosis.     

Flexible metal film with micro- and nanopatterns transferred by electrochemical deposition

A new method for patterning microstructure on metal film by electrochemical deposition is provided. The metal film with micropattern can be peeled off after the deposition by inter-medium layer of resistant molecules such as triglyceride. We can use the technology of electrochemical deposition to make the metal film possess different functions such as soft and bendable properties. We also give an example to get the protein pattern transferred on the metal film. So, this method can also provide a way for the fabrication of protein pattern on the chip.     

Simulation in electrochemistry using the finite element method: Part 1: The algorithm

The finite element method (FEM) is well known in engineering technology. Numerous commercial packages are available. Extensions using an algorithm with an adaptive grid make this method very useful for a great variety of problems. This paper shows the applicability of this powerful tool to electrochemical problems in a general manner. In a first step, the mathematical equations are generalised to handle flexibly different electrochemical mechanisms and electrode geometries. Then, the finite element method is applied to these formulations and electrochemical boundary conditions are introduced. The spatial and time discretisations are discussed and a new method for flux calculation is introduced. Essential advantages of the adaptive finite element (AFE) algorithm are its flexibility and its applicability to many types of electrochemical processes and methods.     

Use of Wittig reaction for the synthesis of conjugated Aza-BODIPYs and their spectral and electrochemical properties

The 2-formyl 1,3,5,7-tetraaryl aza-BODIPY and 2-formyl-6-bromo 1,3,5,7-tetraaryl aza-BODIPY were subjected to Wittig reaction with three different ylides under simple reaction conditions and afforded the conjugated aza-BODIPYs in high yields. The aza-BODIPYconjugates resulted from 2-formyl-6-bromo aza-BODIPYs were reacted further with 4-anisyl boronic acid under mild Pd(0) coupling conditions and afforded 1,2,3,5,7-pentaaryl aza-BODIPYconjugates. The method works efficiently and allows to introduce different substituents at the aza-BODIPY core. All compounds were characterized by HRMS, 1D, 2D NMR, absorption, fluorescence and electrochemical techniques. The spectral and electrochemical studies indicated that the introduction of conjugated substituents at the aza-BODIPY core alter the electronic properties significantly.     

纳米电极时空分辨监测单个PC12细胞多巴胺量子释放

细胞作为有机体结构与生命活动的基本单位 ,在生命体内的新陈代谢和信息传递等方面起着关键作用 .而细胞受激释放是其参与生命活动的形式之一 ,在整个生命活动中起着非常重要的作用 ,不正常的细胞释放会导致生物体功能紊乱 ,以致产生各种疾病 .对细胞释放进行研究在神经生物学、生物化学、临床、病理和药学等多个学科领域中都具有非常重要的意义[1] .由于细胞的超微体积以及胞内单个囊泡量子释放发生的时间是毫秒级的 ,因此需要一种快速灵敏检测的手段才能对胞内释放情况进行实时监测 .对于多巴胺、肾上腺素、去甲肾上腺素及五羟色胺等具有…     

电化学沉积制备光响应聚合物薄膜及其光信息存储应用

设计并合成了一种具有较高电化学活性的偶氮苯类光响应前体小分子, 并用紫外-可见吸收光谱表征其顺反异构性质. 通过电化学沉积方法将小分子前驱体制成表面平整且高度交联的聚合物薄膜, 利用交联薄膜致密的堆积方式增强其稳定性. 以355 nm双干涉激光辐照薄膜, 使其发生光致图案化, 形成周期性强及结构完整的表面起伏光栅结构, 结果表明, 这种在高度交联光响应薄膜基础上形成的光致表面图案化在常用溶剂浸泡和较高温度加热时仍保持清晰的光栅结构, 具有较高的稳定性.     

Substrate effect on the electrochemical capacity pattern (ECP) of PbS

Different metals (Zn, Cu, Pb) were electrodeposited on indium tin oxide (ITO/metal). ITO/metal was used as a substrate for ZnO and PbS deposition, and finally the PbS surface was encapsulated with ZnS. The electrochemical capacitance, C_EC, of each thin layer was calculated from the cyclic voltammetry data and plotted against the applied potential. The plots showed different electrochemical capacity pattern (ECP) for PbS with different metal substrates. It seems that these patterns are effectively controlled by the ECP of the metal substrates. Also, the PbS C_EC values were calculated from electrochemical impedance spectroscopy, EIS, to be compared with PbS C_EC values obtained from cyclic voltammetry. The results of this comparison were completely consistent with each other and confirm different metal as a substrate effects on the PbS and may lead to a structure with different ECP. In the X-ray diffraction pattern, the presence of different preferential orientation of metal crystals was confirmed, which have been leaded to the formation of PbS deposits with different ECP.     

Electric‐Field Distribution at the End of a Charged Capillary—A Coupling Imaging Study

The electric‐field distribution at the end of a charged capillary system is detected using a scanning electrochemical microscopy (SECM) coupling imaging mode. A theoretical model based on the resistance of solution at the capillary end describes the three‐dimensional distribution of the electric field. The effect of the detection electrode position and separation high voltage on solution potential is observed and analyzed. Results demonstrate that the electric field at the end‐channel shows an isopotential contour changing from a disk shape into a hemispherical shape when leaving the capillary opening. The solution potential decreases along the central axis of the capillary to the detection reservoir. In the same scanning plane, the solution potential decreases along the radial direction. Increase of the separation high voltage results in the increase of the absolute solution potential but does not change the relative spatial electric‐field distribution.