Co3O4 microtubules derived from a biotemplated method for improved lithium storage performance

A simple and effective biotemplated method is applied to fabricate porous microtubular cobalt oxide by infiltration of cotton fiber with a cobalt nitrate solution, followed by annealing at 500 °C in air. The as-obtained Co₃O₄ have been characterized by: X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), N₂ adsorption and desorption measurements, and thermal analysis (TG). According to these results, the as-prepared Co₃O₄ display a perfect tubular morphology and mesoporous features. The electrochemical performance of the as-obtained sample was studied for use as a lithium-ion battery anode material by cyclic voltammetry (CV), and charge-discharge and electrochemical impedance spectroscopy (ESI) measurements. Compared to bulk Co₃O₄ and previously reported nanostructured Co₃O₄ electrodes, mesoporous microtubular Co₃O₄ show an improved lithium storage properties, which can be attributed to their unique morphology, large specific surface area and mesoporous feature.     

硫酸盐三价铬电镀中铵盐的作用及影响

研究了铵盐在硫酸盐体系三价铬电镀中的作用.通过赫尔槽试验、沉积速率、极化曲线、循环伏安法等方法研究了铵盐对三价铬镀液的电沉积特性的影响.并采用Tafel曲线、电化学阻抗谱EIS测试及铜盐加速醋酸盐雾试验(CASS),对在不同浓度铵盐的镀液中得到的镀层耐蚀性进行了测试.结果表明,铵盐在镀液中不仅起导电作用而且起配位作用....     

铸钢件黑色磷化工艺的研究

通过对黑色磷化各种工艺因素的研究,确定了铸钢件锰系中温黑色耐磨磷化工艺的最佳方案.采用体视显微镜研究了磷化膜表面微观形貌;采用X射线荧光光谱法(XRF)对磷化膜的厚度和成分进行了测定;采用点蚀法对磷化膜的耐蚀性进行了研究.结果表明,磷化膜性能好,磷化液污染小,便于维护和调整;温度适中,节约能源.本文还对磷化液中各成分作用进行了理论分析.     

温度对钒电池性能的影响

利用自行组装的实验室用钒氧化还原液流单电池,考察了25～45℃范围内温度对钒电池充放电电压、库仑效率、能量效率和自放电性能的影响,并对其影响机理进行了初步研究和讨论.结果表明:随着温度的升高,钒电池的平均库仑效率从25℃时的90.7%降到了45℃的87.4%;而电池的能量效率从25℃的81.6%降到了45℃的78.8%.研究表明:温度对电池自放电性能的影响尤为明显,在25℃时,电池的开路电压保持在0.8 V以上的时间为27 h,而在45℃则只能保持16 h.     

硫酸盐三价铬电沉积铬-磷合金工艺的研究

优选和开发了一种在质量浓度低的硫酸盐三价铬镀液中电沉积铬-磷合金的工艺。采用正交实验法得到了最佳镀液组成和工艺条件,并对镀液和镀层的性能进行了测试。测试结果显示:镀液的稳定性好,沉积速率快,光亮电流密度范围宽;镀层外观光亮,结合力、耐蚀性优良。     

Conformational analysis of peptides using Monte Carlo simulations combined with the genetic algorithm

In this paper, genetic algorithm (GA) was used to both sample the conformational spaces and thoroughly search the global conformations of peptides. δ-conotoxin PVIA, a peptide of 29 amino acids, was used to test our procedure. The results indicated that this procedure could not only successfully explore a set of the conformational spaces using a hybrid Monte Carlo simulations/GA minimization but also find the global conformations for most of peptides using pure GA minimization.     

Low-temperature diffusion brazing of actively metallized Al2O3 ceramic tube and 5A05 aluminum alloy

A low-temperature ceramic–metal joining technique was successfully developed to produce a vacuum-tight Al₂O₃ ceramic and 5A05 aluminum alloy joint, with leak rates of less than 1.0 × 10^− 9 Pa∙m³/s. This involved two steps: active metallization of the Al₂O₃ ceramic surface using Ag–Cu–TiH₂–B composite filler, followed by diffusion brazing of metallized Al₂O₃ ceramic and 5A05 alloy at 530 °C. The microstructure, interfacial reactions and mechanical properties of the actively metallized Al₂O₃ ceramic and diffusion-brazed Al₂O₃/5A05 joint were investigated. The joint properties were determined by the formation of a continuous Ti₃Cu₃O reaction layer adjacent to Al₂O₃ ceramic, in situ synthesized TiB whiskers in the brazing seam, and dissolution thickness of 5A05 alloy. The maximum shear strength of the bonded joints reached 70 MPa, while fracture propagated in the Al₂O₃ substrate, with a bowed crack path. A model for quantitatively evaluating the dissolution thickness of 5A05 aluminum alloy during diffusion brazing process was established.     

碱性二次锌电池电解液添加剂研究进展

电解液添加剂是改善碱性二次锌电池中锌电极性能的重要手段,本文总结了添加剂在抑制锌电极的枝晶、变形、腐蚀及钝化等方面所起的作用,综述了各种无机和有机添加剂的研究进展,对已研究的有机添加剂进行了详细分类.     

锌电极在含三乙胺、二乙胺电解液中的性能

研究了碱性电解液中添加剂三乙胺[(C2H5)3N]、二乙胺[(C2H5)2NH]及两者混合对锌电极的影响.三乙胺与二乙胺混合,可改善锌电极的腐蚀和钝化性能,腐蚀电位负移了0.01～0.02 V,钝化过电位增加了0.05～0.08 V,且能提高可逆性,当V(KOH)∶V[(C2H5)3N]∶V[(C2H5)2NH]=100∶0.5∶0.5时,效果最好;二乙胺单独使用会降低锌电极的可逆性,不适于单独作为添加剂;三乙胺在改善锌电极性能上没有明显的效果.