Growth mechanisms of Ag and Cu nanodendrites via Galvanic replacement reactions

Dendritic silver and copper crystals were produced via Galvanic replacement reactions on zinc and aluminum plates, respectively. The growth orientations of these metals were determined using electron microscopy. The results showed that a fast crystal growth associated with a high concentration of metal cations led to kinetically controlled growth along the <112> axes of the cubic close-packed structures. However, a slow growth rate resulted in thermodynamically controlled growth along the ...     

低压铸造与紫铜结晶器研究

介绍了低压铸造的基本原理及优点,叙述了低压铸造技术在铜合金及紫铜材料领域的研究应用,研究了低压铸造紫铜的铸型材料选择及工艺设计方法,展望了低压铸造紫铜结晶器方面的发展前景,对实际生产具有一定的指导意义。     

Cu(Ⅱ)—苯并三氮唑配合物吸附波的极谱研究

在0.02mol/dm~3NH_4Cl-0.02mol/dm~3TEA-1.5×10~(-4)mol/dm~3BTZ底液中,悬汞电极上,Cu(Ⅱ)与苯并三氮唑配合物有一灵敏的极谱吸附不可逆还原波。本文用半微分极谱法进行了研究。峰电位随扫描速率增加而负移。当扫速为100mV/s时,Ep为-0.65V(vs.SCE)。t_(ads).60s时,峰高与铜浓度0.0005～0.065μg/ml之间存在正比关系。测得吸附配合物组成Cu:BTZ为1:1,条件形成常数β=3.5×10~4。在电极表面上,配合物的吸附近似服从Langmuir吸附等温式,其吸附系数α=7.9×10~4。方法应用于人体血清、头发、胃液和胃癌组织中微量铜的分析,与阳极溶出伏安法相对照,结果满意。     

天然水中铜(Ⅱ)、铅(Ⅱ)和镉(Ⅱ)与碘络合吸附波的示波极谱测定的研究

在醋酸－醋酸钠缓冲溶液中，铜（Ⅱ）、铅（Ⅱ）和镉（Ⅱ）与碘（Ⅰ）都可生成稳定络合物，并且能在滴汞电极表面被吸附，产生灵敏的络合吸附波，示波极谱的峰电位（ＶＳＳＣＥ）依次为－０．５３Ｖ．－０．６６Ｖ和－０．８２Ｖ。本法测定上述三种物质的灵敏度均可达到１０－８ｍｏｌ／Ｌ数量级，具峰电流值与铜（Ⅱ）．铅（Ⅱ）和镉的浓度的线性范围依次为６．４ｘ１０－９－３．３ｘ１０－８ｍｏｌ／Ｌ．０－４．１ｘ１０－８ｍｏｌ／Ｌ和０－５ｘ１０－８ｍｏｌ／Ｌ。采用此底液不但灵敏度高，吸附波形好，能同时测定多种物质，而且１２小时内峰电流不发生明显的改变，此法便于在水质监测中应用。本文还对铜（Ⅱ）、铅（Ⅱ）和镉（Ⅱ）与碘（Ⅰ）络合吸附波的性质进行了讨论     

Cu(Ⅰ)与Cu(Ⅱ)相互转化的热力学研究

本文运用化学热力学循环,系统地阐述了Cu(Ⅰ)与Cu(Ⅱ)相互转化条件,     

表面活性剂对铜电成核动力学行为的影响

用玻碳电极研究了铜在表面活性剂存在下的电化学成核动力学行为，根据成核模型了其成核速度常数，并讨论了过电位及表面活性剂对电成核过程的作用机理。     

铝电解槽阳极效应预报

阳极效应是铝电解槽生产过程中的一种特殊现象,具有电耗高,突发性等特点.本文提出最小二乘统计算法模型,将计算的槽电阻斜率和相关系数结果用来预报阳极效应,通过对电解槽打壳/加料来控制效应系数.实验结果表明,这种预报算法具有有效性和准确性.     

电镀非晶态Ni-P合金的研究

采用Ni-P合金阳极在Watt型镀液中电镀,获得了高光洁度、高硬度和耐蚀的非晶态Ni-P合金镀层,建立了最佳工艺条件,并研究了温度、电流密度及镀液中H_3PO_4含量等对沉积速度,合金中磷含量,合金硬度等的影响;对Ni-P合金镀层结构的研究结果表明,采用Ni-P合金阳极,可使合金镀层具有更高的含磷量,且变化范围较小,在研究范围内获得的Ni-P合金均为非晶态结构。     

铜渣氯化焙烧脱铜机理和动力学研究

采用氯化焙烧可有效实现铜渣中含铜、铁物相CuO和Fe3O4的选择性氯化挥发分离,氯化剂种类不同铜氯化挥发过程特异性明显.FeSO4·7H2O为添加剂,NaCl和CaCl2为氯化剂分别对CuO进行氯化焙烧时,物料失重可分为主要失水阶段、微量失水阶段和氯化失重阶段三部分,其中氯化失重部分反应属一级反应.CaCl2焙烧起始反应温度较NaCl较低为315.9℃,且其焙烧反应活化能4.826KJ/mol低于NaCl 6.001KJ/mol.影响CuO氯化挥发效果的主要因素为焙烧温度,焙烧温度1130℃、焙烧时间60min、氧气流量0.2L/min、CaCl2加入量1.6(CaCl2与铜渣质量比)和FeSO4·5H2O加入量4.42(FeSO4与铜渣质量比)条件下,焙烧物料失重率最大达62.3%,基本可实现物料中铜的氯化挥发,同时铁氯化损失率较小,可实现铜铁氧化物的选择性氯化挥发分离.     

Double carbon decorated lithium titanate as anode material with high rate performance for lithium-ion batteries

Spinel lithium titanate(Li_4Ti_5O_(12)) has the advantages of structural stability, however it suffers the disadvantages of low lithium-ion diffusion coefficient as well as low conductivity. In order to solve issues,we reported a simple method to prepare carbon-coated Li_4Ti_5O_(12)/CNTs(C@Li_4Ti_5O_(12)/CNTs) using stearic acid as surfactant and carbon source to prepare carbon coated nanosized particles. The obtained Li_4Ti_5O_(12) particles of 100 nm in size are coated with the carbon layers pyrolyzed from stearic acid and dispersed in CNTs matrix homogeneously. These results show that the synthesized C@Li_4Ti_5O_(12)/CNTs material used as anode materials for lithium ion batteries, presenting a better high-rate performance(147 m Ahg~(-1)at20 C). The key factors affecting the high-rate properties of the C@Li_4Ti_5O_(12)/CNTs composite may be related to the synergistic effects of the CNTs matrix and the carbon- coating layers with conductivity enhancement. Additionally, the amorphous carbon coating is an effective route to ameliorate the rate capability of Li_4Ti_5O_(12)/CNTs.