Molybdate and tungstate as corrosion inhibitors for cold rolling steel in hydrochloric acid solution

The inhibition effects of molybdate and tungstate on the corrosion of cold rolling steel (CRS) in hydrochloric acid solution (0.1-0.5 M) were investigated by weight loss and electrochemistry methods. The results reveal that both molybdate and tungstate are very good inhibitors with little concentration. The adsorption of inhibitors on the CRS surface basically obeys the Langmuir adsorption isotherm equation. The effect of temperature on the corrosion behavior of CRS was also studied at 25 °C and 35 °C, the thermodynamic parameters such as adsorption heat (ΔH⁰) and adsorption free energy (ΔG⁰) were calculated. In the same conditions, a comparative study of corrosion inhibition of molybdate and tungstate indicated that molybdate was the better inhibitor in 0.1 M HCl. However, the value of percentage inhibition efficiency (IE) was dependent on the concentration of inhibitors in 0.2-0.5 M HCl. It seemed that molybdate did not have the strong inhibitive effect compared to tungstate with relatively small concentration of inhibitors, but molybdate was a better inhibitor over a wide concentration range of inhibitors. A kinetic study of cold rolling steel in uninhibited and inhibited acid was also discussed. Various parameters such as rate constant k and the kinetic parameter B were calculated for the reactions of corrosion. Polarization curves showed that both molybdate and tungstate are mixed-type inhibitors in acidic media.     

Correction to: An Updated Index Including Toughness for Hot-Cracking Susceptibility

Metallurgical and Materials Transactions A -     

An Updated Index Including Toughness for Hot-Cracking Susceptibility

Metallurgical and Materials Transactions A - Hot cracking is one of the major defects that can occur in laser-based additive manufacturing. During the terminal stage of solidification, hot cracking...     

二进制粒子群算法中V型转换函数的应用分析

二进制粒子群算法(BPSO)由于规则简单、参数设置较少等优点被广泛应用到各领域,但是其具有过强的全局搜索能力,缺乏局部的搜索能力等缺陷。针对BPSO存在的缺陷很多文献提出了改进方法,但是针对转换函数的改进较少。通过定义粒子间的距离来分析出BPSO所存在的缺陷,从而进一步分析BPSO中S型转换函数的缺点,并且有针对性地提出更符合BPSO要求的V型转换函数。实验结果表明,所提V型转换函数能克服原始BPSO的缺陷,相比S型转换函数以及现有文献所提的V型转换函数更能提升算法的性能,得到更高的分类准确率。     

The effect of neutral red on the corrosion inhibition of cold rolled steel in 1.0 M hydrochloric acid

The corrosion inhibition of neutral red on the corrosion of cold rolled steel in 1.0 M hydrochloric acid (HCl) was studied using weight loss method and potentiodynamic polarization method. Results obtained revealed that neutral red is an effective inhibitor. It was found that the adsorption of neutral red could prevent steel from weight loss and the adsorption accorded with the Langmuir adsorption isotherm. Potentiodynamic polarization studies showed that neutral red mainly acted as a mixed-type inhibitor for steel in 1.0 M hydrochloric acid. Thermodynamic parameters such as adsorption heat, adsorption entropy and adsorption free energy were obtained from experimental data of the temperature studies of the inhibition process at four temperatures ranging from 30 to 45 °C. The most suitable range of inhibitor concentration was discussed. The kinetic data such as apparent activation energies and pre-exponential factors at different concentrations of the inhibitor were calculated, the effect of the apparent activation energies and pre-exponential factors on the corrosion rates of cold rolled steel was discussed. The inhibitive action was satisfactorily explained by using both thermodynamic and kinetic models. Synergism between chloride ion and neutral red was proposed. The results obtained from weight loss and potentiodynamic polarization were in good agreement.     

卫星遥感技术在海洋倾废中的应用进展

海洋污染始终是全球热议问题,人为倾废活动是引起该类问题的主要原因,利用监测手段研究海洋倾废活动可以更好地掌握海洋环境的变化及污染程度。重点总结了传统监测方法及遥感技术在海洋倾废监测中的研究进展,进一步分析了传统方法和极轨卫星在研究中的局限性,探讨了地球同步轨道卫星在实际应用中的进步和优势,结合实际应用结果指出地球同步轨道水色卫星在目前研究过程中存在的问题,并对今后的研究方向进行了展望。     

多媒体技术在高校教学应用中的优缺点分析

本文在对多媒体技术含义和多媒体技术应用的必要性分析的基础上,肯定了其应用中的优点,同时也找出了其很多不足之处,并针对这些不足提出了一些建议性的对策.     

基于Linux的防火墙技术

随着Ｉｎｔｅｒｎｅｔ应用的普及,其安全性总理２也日益突出,详细讨论了如何利用Ｌｉｎｕｘ操作我建防火墙和代理服务器,以实现内部网络的存取访问控制和流量统计的功能。     

An isoquinoline alkaloid from the Chinese herbal plant Corydalis yanhusuo W.T. Wang inhibits P-glycoprotein and multidrug resistance-associate protein 1

Overexpression of P-glycoprotein (P-gp) and multidrug resistance-associate protein 1 (MRP1) is a major mechanism leading to multidrug resistance (MDR) of cancer cells. These transporters expel anti-cancer drugs and greatly impair therapeutic efficacy of chemotherapy. A Chinese herbal plant Yanhusuo (Corydalis yanhusuo W.T. Wang, YHS) is frequently used in functional food and traditional Chinese medicine to improve the efficacy of chemotherapy. The objective of this work was to study effects of glaucine, an alkaloid component of YHS, on P-gp and MRP1 in resistant cancer cells.The resistant cancer cell line, MCF-7/ADR and corresponding parental sensitive cells were employed to determine reversal properties of glaucine. Glaucine inhibits P-gp and MRP1-mediated efflux and activates ATPase activities of the transporters, indicating that it is a substrate and inhibits P-gp and MRP1 competitively. Furthermore, glaucine suppresses expression of ABC transporter genes. It reverses the resistance of MCF-7/ADR to adriamycin and mitoxantrone effectively.