基于分形理论分辨重叠峰的新算法

将分形理论用于仪器分析信号的解析,提出一种面向分析谱图中重叠信号处理的分形分辨算法.通过对信号进行分形分析,采用分形维数可有效地反映信号的特征,准确地得到谱峰个数和位置的信息,避免人为判断的误差,实现重叠复合信号的分辨.实验表明,这种新的重叠谱峰分辨法能用于光谱、电化学、色谱等仪器分析数据的处理     

尖晶石LiMn2O4锂充放电池的电化学研究

本文报导尖晶石型ＬｉＭｎ２Ｏ４化合物的制备方法，用循环伏安法和交流阻抗技术研究了Ｌｉ／有机电解液／ＬｉＭｎ２Ｏ４电池的电化学行为，用分形理论首次考察和进一步讨论电极材料的阻抗行为随锂离子嵌入或脱嵌电极时的变化。     

电化学沉积CdSe纳晶薄膜的性能及沉积机理

电化学沉积是半导体薄膜制备的一种简便方法,常用于Ⅱ-族化合物半导体薄膜的制备.通过电沉积条件的适当改变可成功地在导电衬底上制备半导体纳晶薄膜^[1].CdSe薄膜作为一种透光性好、导电性好的半导体材料,可进行光学性能和光电性能方面的研究,而半导体纳晶多孔电极的光电化学特性与体材料之间有很大不同.本文采用电化学沉积法制备了CdSe纳晶薄膜并研究了其性能,通过扫描隧道显微镜(STM)形貌分形分析进一步研究其沉积机理.     

分形理论及其在高分子科学中的应用

介绍了分形的基本概念，分形维数的定义及计算方法，讨论了近年来分形理论在高分子科学研究方面的一些应用，内容主要包括高分子溶液、高分子材料的磨损，断裂及界面，高分子结晶过程、导电高分子等。     

分形表面及其性能

本文介绍了分形、分维的基本概念及分形表面的实验分析方法，评述了分形表面的性能。     

Pd沉积在聚乙烯醇缩甲醛衬底上分形结构研究

用透射电子显微镜（ＴＥＭ）研究了衬底和沉积速率对气相沉积在聚乙烯醇缩甲醛衬底上的Ｐｄ膜显微结构的影响，当衬底温度由高到低改变时，Ｐｄ膜结构由紧密岛向分形渐变，在２３３－２５３Ｋ时Ｐｄ膜具有分形结构，用Ｓａｎｄｂｏｘ方法测量了其分维数，在相同温度的衬底上，沉积速率不同时，基分形的图样不同，研究表明，上述分形结构是稳定的，利用有边缘扩散的ＤＬＡ模型了这些实验结果。     

金属线电极分形生长的模拟

电沉积金属过程中,阴极沉积的金属边缘会出现包括枝晶生长在内的许多复杂形态,这会严重影响电沉积产品的质量和加工过程中的电流效率. 对枝晶分形生长的过程以及形貌进行研究,可以实现对沉淀物的可控生长. 本研究使用Python和Matlab软件相互结合,基于扩散限制凝聚（DLA）模型,建立平行线电极电沉积的模型. 通过分析不同粒子数、沉积概率、电极间距、运动步长、定向漂移条件下的分形生长的变化规律,以及模拟参数与实际电沉积因素对分形生长影响的内在联系,发现只要合理控制模拟的粒子数、沉积概率、线电极间距、运动步长、定向漂移概率参数即可与实际电化学体系的浓度和沉积时间、还原概率、两极间距、温度和电压、电极的相对位置和形状一一对应,从而模拟得到跟实际电沉积接近的分形图,最终可实现对分形生长的可控操作,对分形生长在工业电沉积等方面应用有很大的意义.     

焦化过程半焦孔隙结构时空变化规律的实验研究——孔结构的分形特征及其变化

应用分形理论的概念，结合压汞法测得的半焦孔隙结构数据，建立孔结构分形特征模型，考察了焦化过程中不同焦化温度、不同横向空间位置半焦孔隙结构分形特征及其变化规律。结果表明，孔径大于5μm 的孔不具有分形特征，孔径为20nm～5μm孔的孔隙结构具有分形特征，其分形维数为2.45～2.83，可以用分形维数定量表征孔隙结构；相同空间位置下，半焦孔结构分形维数低温时较高，随温度逐渐升高先减小，然后增大再减小；同一空间位置不同温度下分形维数的变化量较小(< 0.15)，表明温度对半焦孔隙结构复杂程度的影响不明显；相同焦化温度下，半焦中心和边缘处的孔结构分形维数大于中间部位，表明中心位置和边缘位置处的孔隙结构要比中间位置处的复杂。     

电化学沉积金属银的二维枝晶生长及其结构

用电化学沉积方法,在液面有机单分子层诱导下生长出二维银膜。当电极电位由高向低快速转换时,银膜边界发生形态转变,生长出大量枝晶,尺度为几十微米,旁枝与主枝夹角约为60°,且具有明显的分形自相似结构。     

再生催化剂表面的变维分形表征

基于分形几何理论，以失活的催化剂化催化剂的再生为研究对象，用静态重量吸附法测定了经历不同再生阶段催化剂表面的单层饱和吸附量，计算得到了不同再段催化剂表面的分形维数，考察了其表面形貌在再生过程中的变化规律，研究结果表明，整个再生过程中，催化剂表面的分形维数在2．5－3．2之间有规律的发生变化，即从再生开始到结束，表面的分形维数由小变大，再由大变小然后趋于稳定。催化剂颗粒的电镜分析结果与实验数据一致。     

Disordered grown systems: Generation and fractal analysis. Electrodeposition

The basic concepts of fractal geometry are reviewed and applied to quasi-two-dimensional zinc electrodeposits. Among the different structures developed during zinc electrodeposition, we have identified the open texture (obtained at large zinc sulfate concentration and small applied potential values) as a typical fractal self-similar structure. © 1994 John Wiley & Sons, Inc.     

金属锌电沉积过程的分形研究

对金属锌电沉积过程中的二维枝晶生长进行了研究,分析了外加电压、电解质浓度以及温度等实验条件对电沉积产物形貌及其分形维数的影响.结果表明,随着外加电压的增大,沉积产物形貌的变化趋势为由开放的分枝结晶向较为致密的生长形貌转变;随着硫酸锌浓度的增大,沉积产物具有分叉结构的致密纤维状枝晶簇和较为粗壮的开放型规则的分叉状枝晶,分形维数发生相应的变化;随着温度的升高,沉积产物的枝晶呈均匀化、致密化,沉积产物分形维数呈明显增大的趋势.     

Morphology of platinum electrodeposits in the three-dimensional sublayer to full layer range produced under different potential modulations on highly oriented pyrolytic graphite

The topography of platinum electrodes produced by electrodeposition (19 to 200 mC cm-2) on highly oriented pyrolytic graphite (HOPG) under different potential modulations was investigated by atomic force microscopy, scanning tunneling microscopy, and H-atom electrosorption voltammetry. To modulate electrodeposition, (i) triangular potential cycling at 0.1 V s-1, (ii) a linear cathodic potential at 0.1 V s-1 and anodic potential step cycling, and (iii) square wave potential cycling at 5000 Hz were utilized. AFM and STM imaging showed that at lower platinum loading the HOPG surface was partially covered by a 3D sublayer of platinum. Electrodes produced by procedure (i) were made of faceted platinum aggregates of about 200 nm and nanoclusters in the range of 5-20 nm; those that resulted from procedure (ii) consisted of anisotropic aggregates of nanoclusters arranged as quasi-parallel domains. These electrodes from (i) and (ii) behaved as fractal objects. The electrodes resulting from procedure (iii) exhibited a flat surface that behaved as a Euclidean object. For all WEs, as the platinum loading was increased the HOPG surface was fully covered by a thin 3D layer of platinum aggregates produced by electrodeposition and coalescence phenomena. Large platinum loading led to electrodes with fractal geometry. Statistical parameters (root-mean-square height, skewedness, kurtosis, anisotropy, Abbot curve, number of protrusions and valleys, and fractal dimension) were obtained from the analysis of AFM and STM imaging data. Platinum electrodeposition coupled to either H-adatom formation for procedures (i) and (ii) or phonon dispersion for (iii) was involved in the surface atom rearrangements related to electrofaceting. The H-adatom electrosorption voltammetry data were used to evaluate the real electrode surface area via the voltammetric charge and to advance a tentative explanation of the contribution of the different crystallographic facets to the global electrochemical process dominated by weak H-Pt adsorption interactions.     

铅锡合金薄层电沉积形态研究

研究铅锡合金薄层电沉积物的形态及其形态随电解液含不同铅锡离子浓度的转变.实验表明,沉积物呈现出不同的形态,包括枝晶型、分枝型、密枝型、分叉型和线状型.这些形态变化从根本上是由于晶体生长各向异性的变化和沉积物的生长速率不同造成的.     

铜电结晶的研究进展*

铜具有的优良导电性和机械加工性能以及其电沉积工艺的诸多优点,决定了铜电沉积在各行业特别是近年在高新技术中的广泛应用。铜的电结晶过程是铜电沉积的初期阶段,它决定了后续的电沉积过程及最终镀层的结构和性能,因此一直是研究的热点。本文综述了铜电结晶的研究方法、电结晶理论研究的进展,详细讨论了pH值、添加剂、金属离子、基体以及电沉积条件等因素对铜电结晶的机理和成核动力学的影响,并对研究中存在的问题提出了展望。     

Prospects of electrochemically synthesized hematite photoanodes for photoelectrochemical water splitting: A review

Hematite (α-Fe₂O₃) is found to be one of the most promising photoanode materials used for the application in photoelectrochemical (PEC) water splitting due to its narrow band gap energy of 2.1 eV, which is capable to harness approximately 40% of the incident solar light. This paper reviews the state-of-the-art progress of the electrochemically synthesized pristine hematite photoanodes for PEC water splitting. The fundamental principles and mechanisms of anodic electrodeposition, metal anodization, cathodic electrodeposition and potential cycling/pulsed electrodeposition are elucidated in detail. Besides, the influence of electrodeposition and annealing treatment conditions are systematically reviewed; for examples, electrolyte precursor composition, temperature and pH, electrode substrate, applied potential, deposition time as well as annealing temperature, duration and atmosphere. Furthermore, the surface and interfacial modifications of hematite-based nanostructured photoanodes, including elemental doping, surface treatment and heterojunctions are elaborated and appraised. This review paper is concluded with a summary and some future prospects on the challenges and research direction in this cutting-edge research hotspot. It is anticipated that the present review can act as a guiding blueprint and providing design principles to the scientists and engineers on the advancement of hematite photoanodes in PEC water splitting to resolve the current energy- and environmental-related concerns.     

Electrodeposition of gold particles on aluminum substrates containing copper

Electrodeposition of adhesive metal films on aluminum is traditionally preceded by the zincate process, which activates the aluminum surface. This paper presents an alternative approach for activation of aluminum by using films containing 99.5% aluminum and 0.5% copper. Aluminum/copper films are made amenable for subsequent electrodeposition by anodization followed by chemical etching of aluminum oxide. The electrodeposition of gold is monitored with electrochemical impedance spectroscopy (EIS). Analysis of EIS data suggests that electrodeposition of gold increases the interfacial capacitance from values typical for electrodes with thin oxide layers to values typical for metal electrodes. Scanning electron microscopy examination of aluminum/copper films following gold electrodeposition shows the presence of gold particles with densities of 10(5)-10(7) particles cm(-2). The relative standard deviation of mean particle diameters is approximately 25%. Evaluation of the micrographs suggests that the electrodeposition occurs by instantaneous nucleation followed by growth of three-dimensional semispherical particles. The gold particles, which are electrically connected to the conductive aluminum/copper film, support a reversible faradaic process for a soluble redox couple. The deposited gold particles are suitable for subsequent metallization of aluminum and fabrication of particle-type films with interesting catalytic, electrical, and optical properties.     

Spatio-temporal organization in alloy electrodeposition: a morphochemical mathematical model and its experimental validation

This paper proposes a novel mathematical model for the formation of spatio-temporal patterns in electrodeposition. At variance with classical modelling approaches that are based on systems of reaction–diffusion equations just for chemical species, this model accounts for the coupling between surface morphology and surface composition as a means of understanding the formation of morphological patterns found in electroplating. The innovative version of the model described in this work contains an original, flexible and physically straightforward electrochemical source term, able to account for charge transfer and mass transport: adsorbate-induced effects on kinetic parameters are naturally incorporated in the adopted formalism. The relevant non-linear dynamics is investigated from both the analytical and numerical points of view. Mathematical modelling work is accompanied by an extensive, critical review of the literature on spatio-temporal pattern formation in alloy electrodeposition: published morphologies have been used as a benchmark for the validation of our model. Moreover, original experimental data are presented—and simulated with our model—on the formation of broken spiral patterns in Ni–P–W–Bi electrodeposition.