Influence of current density in anodizing of an Al–W alloy

The influences of current density in development of amorphous, barrier anodic films on a metastable, solid solution, Al–6.5at.%W alloy is examined, with focus on enrichments in the alloy, oxidation processes at the alloy/film interface and migration of species in the film. The films were formed at current densities between 0.01–100 mA cm⁻² in sodium tungstate electrolyte and examined by transmission electron microscopy and Rutherford backscattering spectroscopy. Enrichments of tungsten in the alloy develop at each of the selected current densities, with enrichments in the range 2–4×10¹⁵ W atoms cm⁻². Incorporation of tungsten species into the films at the alloy/film interface proceeds non-uniformly, with cycles of local enrichment of the alloy, oxidation of the enriched tungsten and subsequent depletion of the alloy. The tungsten species migrate more slowly than Al³⁺ ions, leading to layering of the film composition. The cyclic incorporation of tungsten species into the film and the migration of tungsten species within the film are similar for the selected current densities, at the resolution of the experiments.     

电解槽控制过程中Al_2O_3浓度特性的研究

对电解槽控制过程中的Al2 O3表现出的一些特性如Al2 O3浓度与槽表观电阻的关系、与电流效率的关系、与AE的关系进行了研究 ,这些研究为电解槽模糊控制技术奠定了基础     

浅谈降低企业成本的途径

企业面临日趋激烈的竞争,如何找到有效降低成本的办法和途径,以提高企业经济效益显得越来越重要.从成本的概念及经济实质引入,以提升成本竞争力为目标,通过分析企业合理成本费用的构成,结合实例说明.从科学发展观的角度出发,对降低成本的手段进行了积极探寻,从而达到完善成本核算内容、优化成本管理、降低成本的目的,以成本管理水平的提高创造企业持久的竞争优势,实现企业更好更快的发展.     

Effect of zwitterion on the lithium solid electrolyte interphase in ionic liquid electrolytes

An understanding of the solid electrolyte interphase (SEI) that forms on the lithium-metal surface is essential to the further development of rechargeable lithium-metal batteries. Currently, the formation of dendrites during cycling, which can lead to catastrophic failure of the cell, has mostly halted research on these power sources. The discovery of ionic liquids as electrolytes has rekindled the possibility of safe, rechargeable, lithium-metal batteries. The current limitation of ionic liquid electrolytes, however, is that when compared with conventional non-aqueous electrolytes the device rate capability is limited. Recently, we have shown that the addition of a zwitterion such as N-methyl-N-(butyl sulfonate) pyrrolidinium resulted in enhancement of the achievable current densities by 100%. It was also found that the resistance of the SEI layer in the presence of a zwitterion is 50% lower. In this study, a detailed chemical and electrochemical analysis of the SEI that forms in both the presence and absence of a zwitterion has been conducted. Clear differences in the chemical nature and also the thickness of the SEI are observed and these may account for the enhancement of operating current densities.     

广东省食品冷冻冷藏业现状及发展趋势

本文对广东省食品冷冻冷藏业于本世纪初的现状和前景作了叙述。提出：行业新的多元化经济已逐步适应市场经济机制,并已发挥了规范市场的作用,令市场进入有序状态。行业的生产管理、工艺技术、产品质量、流通方式都在向国际水平靠拢,由于冷链是新兴产业,交成为我国国民经济新的增长点。     

Design of low-voltage and low-power fully integrated filter based on log-domain current-mode integrator

In this paper a novel log-domain current-mode integrator based on MOS transistors in subthreshold is proposed. The integrator's time-constant is tunable by varying a reference bias current. By use of the integrator, a fifth-order Chebyshev lowpass filter with 0.1dB ripples is designed. The simulation results demonstrate that the proposed filter has such advantages as low power supply(1.5V), very low power dissipation (μW level), nearly ideal frequency response, very small sensitivity to components in passband, and adjustable cut-off frequency over a wide range. The circuit is composed of NMOS transistors and grounded capacitors which make it suitable for fully integrated circuit implementation.     

用电流传输器构成的二阶有源滤波器的研究

本文以电流传输器[CCⅡ^ ]为基本电路元件,用系统模型法对构成的二阶有源滤波器进行了理论分析,并推导了二阶通用滤波器的传递函数。     

用壳聚糖絮凝技术处理废水

本文应用保留蛋白质的壳聚糖絮凝处理制浆造纸的废液,考察了处理废液的最优条件,比较了4种废液的固形物,无机物,有机物,CODCr的含量。     

高速电镀锌工艺试验及其镀层性能

在自制的高速电镀模拟槽内,探索性研究了镀液组成、工艺参数（包括主盐浓度、温度、电流密度、镀液流速等）对镀层结晶取向、镀层表面明度、电流效率的影响,为实现大电流高速电镀准备了基础数据。