Influences of co‐monomers and electrolyte acidity on morphological structure of copper‐in‐copolymer gradient film

In this paper, the influences of composition of copolymers and acidity of electrolyte in an electrochemical reactor on morphological structure of copper‐in‐polymer gradient composite film were investigated. For binary copolymers, poly(acrylonitrile‐co‐methyl acrylate) [P(AN‐co‐MA)] and poly(acrylonitrile‐co‐sodium allyl sulfonate) [P(AN‐co‐SAS)], the charged group ? SO in P(AN‐co‐SAS) improves the swelling of the copolymer phase and copper reduction to form gradient morphology; the carboxylic ester group in P(AN‐co‐MA) is not effective because of its poor hydrophilicity, but it is a cooperating component with P(AN‐co‐SAS) to avoid excess of counterion (i.e., Na⁺) in SCF, which might severely interrupt Cu²⁺ coexistence. The swelling of the polymer phase is helpful to decrease the energy of the transfer ions in SCF and to enhance copper deposition and gradient formation. The increase of surface energy because of cluster growth raises the surface energy level of deposited Cu⁰ clusters. The conteraction between these two energy factors allows the size of clusters to be 50–100 nm. The appropriate H⁺ concentration improves active Cu²⁺ reduction and thus deposited gradient copper phase in the copolymer matrix. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 373–380, 2004     

轨道交通电力监控中的拓扑分析

在轨道交通电力监控中,根据车站对应电力主接线图上的设备图元和连接线颜色变化来实时监控整个车站内的带电情况.采用深度优先搜索算法,根据实时变化的电源电压和设备开断状态,动态地对电力主接线图进行网络拓扑分析并计算图中设备图元的带电情况.该方案在国内多条地铁线路的运营实践中均能够实时准确地完成拓扑着色功能.     

Noise characterization of surface processes of the Li/organic electrolyte interface

The processes occurring in aprotic electrolyte on a lithium electrode in the steady state conditions and under polarization are studied using the method of electrochemical noise characterization. The evidence of the electro-chemical noise measurements on polarized lithium electrodes indicates that the discharge of lithium ions under cathodic polarization, as well as lithium anodic dissolution, is localized under the passive film rather than on its surface. An increase in the polarizing current results in local breakdown of the film; in this case, the electrochemical process emerges on the electrode surface affecting the character of potential fluctuations. The intensity of electrochemical noise significantly increases in the course of cathodic polarization with high currents. The reason is that lithium metal crystals, which are formed under the passive film, perforate the film, and dendrites grow on its surface. The method shows the dependence of electrochemical noise intensity on the nature of the electrolyte and establishes the correlation between the stability of the lithium electrode in the course of cycling and the intensity of fluctuations. This offers an opportunity of using the method of electrochemical noise for screening organic electrolytes for lithium batteries.     

恒电位下电氧化脱色降解酸性橙Ⅱ

采用恒电位模式,在有阳离子交换膜分隔的两室电解槽中以RuO2/Ti阳极对酸性橙Ⅱ进行氧化脱色降解。分别以484 nm、310 nm、255 nm波长处的吸收值为指标,跟踪脱色降解过程。脱色反应符合准一级动力学,表观反应速率常数分别与阳极电位、氯化钠浓度、染料初始浓度之间存在指数函数关系、线性关系和倒数函数关系。氯化钠浓度为40 mmol/L时,染料100%脱色,萘环结构受到一定程度破坏,染料未发生明显矿化。间接电氧化在脱色降解过程中起主导作用,直接电氧化起一定作用。     

铜及其合金电解仿金着色工艺

详细介绍了一种铜及铜合金阴极还原着仿金色工艺及其配方。探讨了该工艺的着色原理、电流密度的影响及所得着色膜层的性能。结果表明，该工艺所得的膜层呈金黄色，结晶致密，耐蚀性好。     

Robust graph coloring based on the matrix semi-tensor product with application to examination timetabling

This paper investigates the robust graph coloring problem with application to a kind of examination timetabling by using the matrix semi-tensor product, and presents a number of new results and algorithms. First, using the matrix semi-tensor product, the robust graph coloring is expressed into a kind of optimization problem taking in an algebraic form of matrices, based on which an algorithm is designed to find all the most robust coloring schemes for any simple graph. Second, an equivalent problem of robust graph coloring is studied, and a necessary and sufficient condition is proposed, from which a new algorithm to find all the most robust coloring schemes is established. Third, a kind of examination timetabling is discussed by using the obtained results, and a method to design a practicable timetabling scheme is presented. Finally, the effectiveness of the results/algorithms presented in this paper is shown by two illustrative examples.     

Proton diffusion in γ-manganese dioxide

Deconvolution of the electrolytic manganese dioxide (EMD) discharge curve has indicated the presence of a number of energetically different reduction processes. This has been used to determine the contribution of each reduction process to the total discharge. Using step potential electrochemical spectroscopy (SPECS), the i-t data were modelled as the sum of the discharge of the individual reduction processes. From this, A√ D for each reduction process as a function of degree of discharge was determined. The maximum A√ D values for each process ranged from 2.3×10⁻² to 4.0×10⁻⁴ cm³ s^−1/2 g⁻¹ values are consistent with previously reported values for A√ D, although in this case we have determined values for the entire compositional range.     

Selective oxidation of pentachlorophenol on diamond electrodes

The influence of electrode potential on pentachlorophenol (PCP) oxidation on boron doped diamond (BDD) electrodes in a 0.1 mol L^–1 Britton–Robinson buffer (pH 5.5) is described. Controlled potential electrolyses were carried at 0.9, 2.0 and 3.0 V vs Ag/AgCl and the solutions analysed by square wave voltammetry, high performance liquid chromatography, chloride ion selective electrode and spectroscopy in the ultraviolet–visible region. At low positive potential (0.9 V), the formation of an adherent film on the electrode surface involving the transference of 1 electron per PCP molecule was observed. The film was identified as the dimer 2,3,4,5,6-pentachloro-4-pentachlorophenoxy-2,5-cyclohexadienone and the current efficiency was as high as 90%. At potentials close to the onset of O₂ evolution (2.0 V), the formation of the corresponding quinone (p-tetrachlorobenzoquinone) was detected at the beginning of the process. This was followed by further oxidation to the hydroxy-benzoquinone with a practically quantitative yield. Electrolyses carried out well into the region of oxygen evolution (3.0 V) lead to the electrochemical combustion of PCP to CO₂ and H₂O as well as to the release into solution of 5 Cl^– ions per PCP molecule destroyed.     

Response surface methodology study on electrochemical adsorption regeneration of water-based drilling fluid waste

ABSTRACT

This study explores an electrochemical adsorption method on the regeneration of aqueous drilling fluid waste. Response surface analysis was applied to investigating the electrochemical factors on the adsorption performance. The response surface polynomial model optimized the preferred electrochemical adsorption conditions with adsorption time of 20 min, spacing electrodes of 5 cm, adsorption concentration of 5% and NaCl concentration of 2 g/L. The model calculated electrochemical adsorption amount of drilling fluid showed only 1.3% deviation from the experimental results. Thus, the model could provide effective support for the device design and application of drilling fluid electrochemical adsorption process.     

选磷厂废水电化学处理循环利用

简要介绍磷矿浮选厂废水（尾矿水）进行电化学处理的研究和处理后循环使用的浮选工艺试验以及含固废水电化学处理的理论基础。试验结果表明：经电化学处理后的废水达到工艺用水水质控制指标；反复循环使用于浮选工艺取得满意效果；电化学处理方法是实现工业废水循环利用的有效手段。