腐蚀电化学研究中的微计算机在线测量与分析 Ⅰ、由极化测量解析计算金属的腐蚀速度

本文介绍了采用通用微型计算机建立的府蚀电化学在线测量系统。它由微计算机控制的恒电位仪、一系列电化学测试控制软件和腐蚀参数测定的应用程序组成。通过计算机程序安排,该系统能自动完成阶梯波电位讯号的产生、电化学测试的进行、数据的采集以及分析计算。由极化数据分析计算金属的腐蚀速度是通过解析腐蚀体系的动力学方程式得到的。通过迭代,解残差方程组,求出金属的腐蚀速度和塔菲尔常数。文章列举了本方法应用的实例,分析和讨论了方法的可靠性和适用范围。     

钽及表面离子渗氮层在碱液中的腐蚀行为

用SEM, XPS对钽及表面离子渗氮层在充分搅拌的50℃的6.5%NaOH中腐蚀前后的表面进行了观察和分析. 证明表面腐蚀产物为NaTaO3和Ta2O5. 结合计算的腐蚀反应的电荷转移数, 给出了钽在碱液中可能的腐蚀反应方程式.     

X65钢在CO_2饱和油田水中的电化学行为和腐蚀机理

利用热力学计算方法推断X65钢在CO2饱和模拟油田水中的腐蚀反应阳极机制。结果显示X65钢在CO2饱和模拟油田水中的腐蚀包含两种阳极反应,即Fe接受电子转变为Fe2 和Fe与HCO3-反应形成FeCO3。实验条件下Fe与水作用生成Fe(OH)2的反应的平衡电位高于自腐蚀电位,因此难以进行。通过电化学阻抗谱测试进一步证实了热力学计算的结果。     

混合电位下的电极过程研究

讨论了混合电位理论的主要发展过程并扼要介绍了我们的研究进展.主要研究结果:提出了一个表示极化电阻与腐蚀电流密度之间的普适性的关系式;首先提出了一个包含4个参数的表示腐蚀过程的阴极反应为混合控制的弱极化方程式;针对不可逆电极过程提出了普适性的法拉第导纳表达式并讨论了相应的电化学阻抗谱(EIS)图形;将相应的理论推广到混合电位下的EIS.最后介绍了混合电位下的EIS理论应用于界面型缓蚀剂研究所得到的主要结果.     

小知识

1．建立炸药爆炸反应方程式都有些什么重要意义？建立炸药爆炸反应方程式，即确定炸药爆炸反应产物的组成，在理论和实际工作上都具有重要意义。一方面，只有确定了爆炸产物的具体组成，才能对炸药的爆热、爆温和爆容等参数进行计算，从而才能对炸药的爆炸威力进行评定；另一方面，只有知道爆炸产物的组成，才能根据需要更好地调整炸药的组成，以提高和改善炸药的爆炸性能。     

用DSC法研究管道熔结环氧粉末涂料固化特性

应用差示扫描量热法（DSC）技术深入地研究了国内广泛应用的管道熔结环氧粉末涂料,通过分析计算确定了内在体系固化反应动力学方程式。对比实验结果表明,动态实验得到的固化反应动力学方程能够较为真实地反映体系实际固化反应过程,在保证固化转化率高于95％的前提下,可为固化工艺的确定提供有力的依据。     

H_2SO_4分解富钛精矿的反应动力学

攀钢含钛高炉渣是一种尚待开发利用的钛资源。选用攀钢含钛高炉渣经选择性分离后的富钛精矿为原料 ,以液固异相反应的收缩未反应芯模型研究了硫酸法制取钛白的反应动力学过程。根据搅拌强度和温度对反应的影响判别反应过程为膜扩散控制过程 ;分析了反应速度的温度因素和粒度因素 ,导出了硫酸分解富钛精矿的动力学方程式 ,并按该方程计算得到反应温度在 6 0～ 80℃的活化能为 34.5 9kJ/mol。     

H2SO4分解富钛精矿的反应动力学

攀钢含钛高炉渣是一种尚待开发利用的钛资源,选用攀钢含钛高炉渣选择性分离后的富钛精矿为原料,以液－固异相反应的收缩未反应芯模型研究了硫酸法制取钛白的反应动力学过程,根据搅拌强度和温度对反应的影响判别反应为膜扩散控制过程,分析了反应速度的温度因素和粒度因素,导出了硫酸分离富钛精矿的动力学方程式,并按该方程计算得到反应温度在60－80℃的活化能力为34．59kJ/mol。     

论不可逆电极过程的法拉第阻抗等效电路类型

根据定态过程的稳定性条件和线性系统的性质,对于扩散过程的影响可以忽略的不可逆电极过程,可以导出恒电位条件下的法拉第导纳方程式,并可据以讨论可能的法拉第阻抗的等效电路。本文讨论了除电极电位E外还有1个和2个状态变量的电极过程的情况。     

在硫酸介质中铜置换贵金属的动力学

硫酸介质中用铜置换Pt、Pd、Au、Rh及Ir,并测定置换率与体系电位变化的关系,研究温度和酸度对置换速度的影响,得出活化能及速率常数方程式。     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

Effect of Short-Time Aging on the Pitting Corrosion Behavior of a Novel Lean Duplex Stainless Steel 2002

The effect of short-time aging in the temperature range between 400 and 1000 °C on the pitting corrosion behavior and mechanical property of a novel lean duplex stainless steel(LDSS) 2002 was investigated through the potentiostatic critical pitting temperature(CPT) tests and the Charpy impact tests. Both the pitting corrosion resistance and the toughness of aged specimens degraded due to the precipitation of detrimental secondary phases and the most significant reduction of CPT and impact energy emerged at 650 °C concurrently. The CPT of LDSS 2002 specimen aged at 650 °C decreased by 28 °C, and the impact energy dropped from 69 to 29 J/cm~2 compared with the solution-annealed sample. Transmission electron microscopy characterization showed that the main precipitates in LDSS 2002 were Cr_2N and M_(23)C_6 along the ferrite–austenite grain boundaries.     

Information for Contributors

正The Transactions of Nonferrous Metals Society of China,founded in 1991 and sponsored by The Nonferrous Metals Society of China,is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology,including mineral processing,extraction metallurgy,metallic materials and heat treatments,metal working,physical metallurgy,powder metallurgy,with the emphasis     

Preface

<正>We are pleased to present this Special Issue of Transactions of Nonferrous Metals Society of China containing selected papers from the First Asian Conference on Aluminum Alloys(ACAA-2013),held in Beijing,China,13–17 October 2013.This conference has been initiated,with approval of     

Information for Contributors

The Transactions of Nonferrous Metals Society of China, founded in 1991 and sponsored by The Nonferrous Metals Society of China, is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology, including mineral processing, extraction metallurgy, metallic materials and heat treatments, metal working, physical metallurgy, powder metallurgy, with the emphasis on fundamental science. It is the unique preeminent publication in English for scientists, engineers, under/post-graduates on the field of nonferrous metals industry. This journal is covered by many famous abstract/index systems and databases such as SCI Expanded, Ei Compendex Plus, 1NSPEC, CA, METADEX, AJ and JICST.     

INTRODUCTION TO PATENTS

The invention provides a method of making a mold which can reduce SOx generation rate while preventing decrease in hardening rate in the case of using sulfuric acid for a hardener composition. The method has a mixture step in which fire-resistant particles, a hardener composition and a binder composition are mixed to obtain a composition for a mold. The hardener composition contains sulfuric acid. In the mixture step, sodium carbonate is added. A molar ratio of the sulfuric acid to the sodium carbonate is 0.5 or more and 4.0 or less.     

China Foundry Week 2014

China Foundry Week, hosted by the Foundry Institution of Chinese Mechanical Engineering Society （FICMES） each year, is a large academic event in China. It is one of the ten high-impact activities sponsored by the Chinese Mechanical Engineering Society.     

17th Conference of Hydrodynamic and Electromechanical Control Engineering Call for papers

正1.Contents In order to promote the academic exchanges and technical communication of the research in the field of fluid power transmission and control,fluid control engineering specialized committee of the Chinese Society of Theoretical and Applied Mechanics will hold the 17th Conference of Hydrodynamic and Electromechanical Control Engineering on July 27-29,2014 in Tibet,Lhasa city.     

Formulas of Tension of Continuous Rolling Process

The development of computer controlled continuous rolling process calls for a mathematical expression that can express the inequality condition of "constant flow". Tension is the link of the continuous rolling process. From the condition of dynamic equilibrium, a differential equation of tension is given out. On the basis of the physical rules established from the industrial practice and experimental studies, the law of volume constancy, the linear relation of forward slip and tension, the state equation of continuous rolling, the formula of dynamic tension, and the formula of static tension have been obtained. These formulae reflect the functional relations between tensions, thickness, roll velocity, and time in the continuous rolling process. It is implied that the continuous rolling process is a gradually steady, controllable, and measurable dynamic system. An assumption of predicting the thickness of a steel plate using these tension formulae is also put forward.