Electrochemical behaviors of gold and its associated elements in various complex agent solutions

Thermodynamic properties and electrochemical behaviors of gold and its associated elements, such as silver, copper, nickel and iron, in various complex agent solutions were studied. Within CS（NH2）2, S2O2-3 and SCN- systems, alkaline thiourea is the optimal nontoxic lixiviating agent substituting cyanide from the viewpoint of thermodynamics. The electrochemical study indicates that the anodic dissolution current densities of gold are 2.616, （1.805,） 1.267, 1.088, 0.556, and 0.145 mA·cm-2 respectively in the solutions of cyanide, alkaline thiourea containing Na2SiO3, SCN-, acidic thiourea, alkaline thiourea and thiosulfate at the potential of 0.500 V. Comparing various lixiviating agents, the alkaline thiourea solution containing Na2SiO3 is of prominent selectivity in leaching gold, in the potential range from 0.500 to 0.600 V, which is most efficient for leaching gold selectively instead of cyanide. The effect on leaching gold is similar to that in the cyanide system.

Effects of complexing agents on acidic electroless nickel deposition

Our previous study reported the influences of different complexing agents on electroless nickel （EN） by examining the properties of the deposits. In the present work, the effects of four common-used complexing agents on EN deposition rate and the stability of solution pH values were examined, either with an acetic pH buffer agent or absent of them. It is indicated that the pH buffeting effect of them is dominative when the EN solution is lack of the pH buffer. Under this situation, the EN deposition rate increases with the concentration of complexing agents increasing. The EN deposition rate decreases with fin＇ther adding the complexing agent when the solution already has enough pH buffer capability. Electrochemical impedance spectroscopy obtained during EN deposition illustrates that, in this case, the enhanced reaction resistance is the main reason for a lower deposition rate. However, the influence of polarization caused by mass transfer is not negligible at high complex ratio for sodium citrate and malic acid EN solutions.

Structure and Shape Control of Hydrothermally Synthesized PbTiO_3 --Effects of pH and Complexing Agents

Tabular PE PbTiO 3, spherical PY PbTiO 3, and acicular PX PbTiO 3 powders were hydrothermally synthesized from triethanolamine(TEA) complexed precursor; clubbed PE PbTiO 3 powders were obtained from diethanolamine(DEA) complexed precursor. The effects of pH of the hydrolyzation as well as complexing agents including TEA, DEA, and MEA(monoethanolamine) on the structure and the morphology of PbTiO 3 powders are discussed. The optimal conditions for hydrothermal syntheses of acicular and clubbed PbTiO 3 powders have been established. The products were characterized by means of XRD, TEM and other techniques.

Application study on complex wetting agent for dust-proof after gas drainage by outburst seams in coal mines

After gas drainage,the outburst seam is dry and,consequently,during subsequent mechanized mining,unwanted dust production is extensive.Because the hard dustfall typically has a small particle size it contains a high percentage of respirable dust.Considering these factors,this paper improved the efficiency of dustfall by reducing the surface tension of the liquid used as a wetting agent,then configuring five kinds of wetting agents by adopting various doses and types of surfactants,neutral inorganic salts and chemical additives,etc.After purchasing DA-85 and SRJ-1 wetting agent,the surface tension and critical micelle concentration of seven kinds of wetting agents were measured using the capillary rise method.Wetting agent A was confirmed to have the best comprehensive effect.The experiments were optimized by measuring and comparatively analyzing contact angles of pure water,SRJ-1 wetting agent and wetting agent A on the surface of different coal samples using a contact angle measurement instrument(HARKESPCA).By comparative analysis,dust-proof effects of seam,dynamic pressure water infusion and highpressure spray in the tunneling face at the Daning coal mine using pure water,wetting agent SRJ-1and A,it was determined that after using wetting agent A,the average dust concentration in the place of the mining machine driver,10 m and 110 m away from the tunneling front is approximately 300 mg/m^3,240 mg/m^3 and 100 mg/m^3,respectively.This practice increased the dust-proof efficiency dramatically and achieved a good comprehensive dust-proof effect.

Fluorescence properties and application of doping complexes Eu_(l-x)L_x(TTA)_3Phen as light conversion agents

Light conversion agents Eul-xLx（TTA）3Phen (L denotes (La3+, Gd3+, Y3+)) complexes were prepared, and the influence of doping ions on fluorescence properties was investigated by elementary analysis, FTIR and fluorescent spectra. The results show that FTIR spectra of Eul-xLx（TTA）3Phen complex system are identical with that of EuTTA3Phen, which indicates that the complexes (Eul-xLx（TTA）3Phen) are similar in structure to （Eu （TTA）3Phen.） For the above doping elements, co-fluorescence enhancement has the following order: Gd3+>Y3+>La3+, and the optimum mole fractions of doping elements are 0.4, 0.2 and 0.5 respectively for Gd3+, Y3+, La3+. Among all the complexes, Eu0.6Gd0.4（TTA）3Phen complex has the strongest fluorescent intensity. Applying Eu0.6Gd0.4（TTA）3Phen complex to plastic and printing inks, bright red fluorescence plastic and printing inks are obtained when the content of europium reaches 0.1%（mass fraction）.

Structure, properties and application to water-soluble coatings of complex antimicrobial agent Ag-carboxymethyl chitosan-thiabendazole

The structure, properties and application to water-soluble coatings of a new complex antimicrobial agent Ag-carboxylmethyl citosan-thiabendazole （Ag-CMCTS-TBZ） prepared from different materiel ratios were reported. The silver ions were preferably coordinated with the free -NH2 groups and the -OH groups of secondary alcohol and carboxyl in CMCTS. TBZ preferably bonded to carboxyl group in CMCTS by electrostatic force and hydrogen bonding. Increase in silver ions content in the complex agent improved to some limited extent the antibacterial activity, but enhanced coloring and cost of the complex agent. Increase in TBZ content resulted in increase of antifungal activity, but decrease of water solubility of the complex agent. The antimicrobial MICs of the complex agent to Esherichia coli, Staphylococcus aureus, Candida albicans, Aspergillus niger, Mucor sp. were 2080, 1560, 2055, 40250, and 4001700mg/kg, respectively. Addition of 0.1% of this complex agent to acrylic emulsion paint made the paint without substantial change in color, luster, viscosity, odor or pH value, but with an excellent and chronically persisting broad-spectra antimicrobial activity.

Spectrofluorometric Study of the Inclusion Complexation of Fluorescent Whitening Agents and β-Cyclodextrins

The inclusion complexation behavior of 2,5-Bis(5-tert-butyl-benzoxazol-2yl)-thiophene (UVOB) with native β-cyclodextrin (βCD) and βCD-monochlorotriazinyl (βCD-MCT) was evaluated by fluorescence spectroscopy. The association constant (Ks), stoichiometry, , and were evaluated at 25℃ ± 0.1℃ in phosphate buffer solution (pH = 10.5, 0.1 mo•dm–3) in order to find out the complex formation ability and stability. Fluorescence enhancement for UVOB and UVBNB with both CDs has been observed as a result of the complex formation. A stoichiometry 1:1 for UVOB in both CDs was observed;a stoichiometry 3:1 for UVBNB in both CDs has been observed. The Ksvalues for UVOB were 4916 ± 137 M–1 and 655 ± 19 M–1 (acetone: water 90/10, v/v) with βCD and βCD-MCT, respectively. The value obtained indicates a spontaneous and stable complex formation, but the complex βCD-UVOB showed high Ks value as an indicative of a high concentration of complex formed. Additionally, Ks and thermodynamic parameters and were evaluated in a commercial product UVBNB (UVOB, 13%, v/v). In aqueous solution, the values obtained were 2552 ± 115 and 1787 ± 75 M–1 respectively. Complexation of UVOB with CDs is an interesting approach for utilization of UVOB in aqueous systems without the need of solvents and or surfactants used in commercial product (UVBNB).

Discrete decision model and multi-agent simulation of the Liang Zong two-chain hierarchical organization in a complex project

Different from the organization structure of complex projects in Western countries, the Liang Zong hierarchical organization structure of complex projects in China has two different chains, the chief-engineer chain and the general-director chain,to handle the trade-off between technical and management decisions. However, previous works on organization search have mainly focused on the single-chain hierarchical organization in which all decisions are regarded as homogeneous. The heterogeneity and the interdependency between technical decisions and management decisions have been neglected. A two-chain hierarchical organization structure mapped from a real complex project is constructed. Then, a discrete decision model for a Liang Zong two-chain hierarchical organization in an NK model framework is proposed. This model proves that this kind of organization structure can reduce the search space by a large amount and that the search process should reach a final stable state more quickly. For a more complicated decision mechanism, a multi-agent simulation based on the above NK model is used to explore the effect of the two-chain organization structure on the speed, stability, and performance of the search process. The results provide three insights into how, compared with the single-chain hierarchical organization, the two-chain organization can improve the search process: it can reduce the number of iterations efficiently; the search is more stable because the search space is a smoother hill-like fitness landscape; in general, the search performance can be improved.However, when the organization structure is very complicated, the performance of a two-chain organization is inferior to that of a single-chain organization. These findings about the efficiency of the unique Chinese-style organization structure can be used to guide organization design for complex projects.

面向任务的重叠联盟结构生成计算复杂性

传统的重叠联盟形成问题大都聚焦智能体,鲜有从任务视角出发.为此,本文首先构建了一种面向任务的重叠联盟结构生成模型,并分析了其解空间和相关决策问题的计算复杂性.此外,基于流网络分别设计了相应的孤立联盟、重叠联盟、重叠联盟结构成功性判别算法和最优重叠联盟结构生成算法.分析结果表明,判别孤立联盟、重叠联盟、重叠联盟结构的成功性的时间复杂度均与智能体数和任务数呈多项式关系,而搜索最优重叠联盟结构的时间复杂度与智能体数和任务数呈指数关系.最后,通过仿真实验验证了上述结果.

响应曲面法优化氯化物体系三价铬电沉积工艺

[目的]三价铬电沉积过程中伴随的剧烈析氢反应导致局部pH升高,是镀速急剧下降、镀层难以增厚及镀层性能恶化的主要原因。[方法]采用甲酸钠、草酸钠和尿素为氯化物体系三价铬电镀的配位剂,以在150 mA/cm^(2)电流密度下电沉积10 min的沉积速率为响应因子,采用响应曲面法优化了镀液配方,建立了氯化物体系三价铬电沉积速率的多项式模型方程。通过单因素实验研究了添加剂、pH、温度、电流密度和沉积时间对沉积速率、镀液深镀能力和镀层耐蚀性的影响。[结果]三价铬电沉积的最佳配方和工艺条件为:三氯化铬0.6 mol/L,甲酸钠0.8 mol/L,草酸钠0.2 mol/L,尿素0.3 mol/L,pH 1.8,温度30℃,电流密度150 mA/cm^(2),时间30 min。在该条件下所得Cr镀层为非晶态结构,厚度在12μm以上,耐蚀性良好。[结论]选用合适的配位剂抑制电沉积过程中铬的羟桥化反应,是维持较高镀速和改善镀层性能的有效手段。

基于Agent的复杂系统建模仿真方法研究进展

由于传统建模方法难于适应复杂系统规模大、结构和层次复杂以及非线性等特点,需要采用新的建模理论和方法.基于Agent的复杂模型构建技术是目前最具活力的方法之一.首先简要介绍了Agent的基本概念及其一般结构,并讨论了基于Agent建模仿真方法的基本思路与特点;然后,综述了基于Agent复杂模型构建技术的研究现状;最后,指出了该建模仿真方法的主要发展趋势.

基于Agent的建模与仿真概念化框架

基于Agent的建模与仿真(ABMS)是面向复杂系统的建模与仿真方法学。提出了基于Agent的建模与仿真概念化框架,重点对该框架中Agent模型的概念及模型转化、ABMS综合环境以及模型校核与验证等相关研究内容进行了阐述。结合该框架,对Agent、消息、复杂系统及基于Agent的仿真进行了形式化描述。最后,提出了一个基于Agent的建模与分布式仿真软件框架,介绍了该框架的主要组成部件,并对实现该框架的相关技术以及正在开展的工作进行了介绍。

基于Agent的复杂系统分布仿真建模方法的研究

基于Agent的分布仿真是研究大型复杂系统的一种有效的、重要的方法。为了减小复杂系统仿真的复杂度,增加仿真模型的重用和可维护性,需要研究基于Agent分布仿真的建模方法。首先对复杂系统及其特性进行了分析,对基于Agent的仿真进行了全面的论述,然后对基于Agent的复杂系统仿真中的复杂系统建模分析、Agent建模分析以及Agent的分布进行了分析,给出了基于Agent的复杂系统分布仿真的建模步骤,最后给出了在此建模思想指导下的金融证券市场的建模过程。

基于Agent的Web网信息传播仿真模型

web网上的信息传播是社会复杂网络与信息复杂网络相互作用的结果。分析了web网和网民社会关系的结构特征,定义了信息价值时变函数,将网民基本行为归纳为读、写、评、传四类。基于多Agent建模方法建立web网信息传播仿真模型,用BA算法生成虚拟信息环境,采用WS模型刻画虚拟社会关系;定义了网民Agent的属性和行为规则,以及网民和网站的交互规则。设计了相关算法,实现了仿真模型,仿真结果表明该模型能够较好地模拟常态下的网络信息传播规律。

战争系统基于Agent建模若干问题的讨论

在笔者前期研究工作的基础上,对战争系统Agent建模的若干问题———与传统建模方法的区别、建模理论、实体与Agent、仿真平台相关问题等进行了深入的讨论。研究表明,基于Agent的建模方法在某种程度上优于传统的基于解析公式的建模方法,为战争模拟所面临的典型复杂问题———战争问题分解、战争问题求解、模型颗粒度问题、聚合与解聚问题、实体能力问题和损耗模型问题等的解决提供了新思路和启迪,其将有望成为战争复杂系统建模仿真的突破口。

基于多Agent的细胞信号转导网络仿真

提出一种基于多层次离散空间和介观水平Agent的层次式多Agent系统仿真细胞信号转导网络。多层次的离散空间可以有效的表示细胞内部环境,而且适于系统的扩展;介观水平Agent封装分子种类的不同状态形式,将系统的复杂性分解在局部范围,并减少了通信以及计算复杂性。给出了对两个MAPK(有时分裂原活化蛋白激酶)通路反馈模型的仿真结果。结果表明基于该方法的仿真与数值仿真结果相吻合,证明了方法的正确性。

基于Agent的军用大型复杂系统建模与仿真

大型复杂系统是 2 1世纪的核心技术之一 ,而军用复杂系统是各发达国家优先考虑的发展对象。在此背景下 ,简述了Agent的组成和原理 ,并对Agent用于军用复杂系统的建模过程进行了深入细致的分析 ,给出了复杂系统仿真模型和仿真结果 。

三价铬电沉积机理研究及镀层表征

在硫酸盐三价铬电沉积体系中,通过赫尔槽实验对不同络合剂含量进行了筛选,得到络合剂最佳含量配比为甲酸铵80 g/L、草酸铵20 g/L以及尿素30 g/L,最佳电流密度范围为5.11 A/dm^(2)~20.68 A/dm^(2);通过循环伏安曲线和阴极极化曲线分析三价铬电沉积机理,发现三价铬的沉积过程分两步进行:第一步为Cr3++e→Cr_(2)+,过程不可逆;第二步为Cr_(2)++2e→Cr,可逆;草酸铵会增大阴极极化,甲酸铵和尿素会降低阴极极化;电沉积20 min得到的铬镀层,XPS分析表面镀层由单质Cr、Cr_(2)O_(3)及Cr(OH)3构成;微观结构观测发现,随着电沉积时间增加,镀层由表面平整形貌逐渐转变为瘤状结构形貌;镀层呈现明显的(110)择优取向;电化学研究表明,相比20 min铬镀层,5 min铬镀层的耐蚀性较好,腐蚀电位由-0.6377 V提高至-0.5633 V,腐蚀电流由6.1030×10^(-6)A/cm^(2)提高至5.4031×10^(-6)A/cm^(2)。

基于复杂agent的水污染运移仿真模拟

针对水污染运移仿真表现力不强的问题,采用复杂性理论思想,在干流河道多尺度分解的基础上形成水质体积微元,建立具有吸附行为、自净行为、沉降行为、挥发行为、平推行为、扩散行为和演化行为的复杂agent模型,开展基于高性能计算技术的agent计算力优化,实现以多agent涌现为特征的污染物运移仿真模拟,并在数字地球上进行可视化表现。实验表明,该方法能够有效反映污染物的演化状况,并可以汇集3S所提供的地形地貌数据,更加丰富直观地表现水污染运移过程。