Formation of the Fe(II)-Fe(III) hydroxysulphate green rust during marine corrosion of steel

Rust layers formed on steel sheet piles immersed 1 m above the mud line for 25 years were analysed by Raman spectroscopy, scanning electron microscopy and elemental X-ray mappings (Fe, S, O). They consist of three main strata, the inner one mainly composed of magnetite, the intermediate one of iron(III) oxyhydroxides and the outer one of hydroxysulphate green rust GR(SO₄²⁻). Simulations of GRs formation in solutions having large [Cl⁻]/[SO₄²⁻] ratios revealed that the hydroxysulphate GR(SO₄²⁻) was obtained instead of the hydroxychloride GR(Cl⁻), as demonstrated by X-ray diffraction and transmission Mössbauer spectroscopy analyses. Measurements of the [S], [Fe] and [Cl] concentrations allowed us to establish that GR(SO₄²⁻) formed along with a drastic impoverishment of the solution in sulphate ions; the [Cl⁻]/[SO₄²⁻] ratio increased from 12 to 240. The GR, acting like a “sulphate pump”, may favour the colonisation of the rust layers by sulphate reducing bacteria.     

Fast computation of computer-generated hologram using Xeon Phi coprocessor

We report fast computation of computer-generated holograms (CGHs) using Xeon Phi coprocessors, which have massively x86-based processors on one chip, recently released by Intel. CGHs can generate arbitrary light wavefronts, and therefore, are promising technology for many applications: for example, three-dimensional displays, diffractive optical elements, and the generation of arbitrary beams. CGHs incur enormous computational cost. In this paper, we describe the implementations of several CGH generating algorithms on the Xeon Phi, and the comparisons in terms of the performance and the ease of programming between the Xeon Phi, a CPU and graphics processing unit (GPU).     

Comparative study in chemistry of microbially and electrochemically induced pitting of 316L stainless steel

Ennoblement of stainless steel (SS) by microbially deposited manganese oxides can lead to pitting corrosion at low chloride concentrations, causing unexpected material failures. We exposed 316L SS to manganese oxidizing bacteria Leptothrix discophora under well-defined laboratory conditions, and then placed the ennobled coupons in a 0.5 M sodium chloride solution until pitting developed. Using time-of-flight secondary ion mass spectroscopy we demonstrated that the pits and their immediate vicinity associated with microbial influenced corrosion had different chemical signatures than those associated with electrochemically induced pitting, suggesting a possibility that the microorganisms were directly involved in pit initiation. Based on the differences in the chemical signatures we were able to distinguish the microbially induced pits from those induced by anodic polarization.     

硫酸盐还原菌引起的微生物腐蚀的研究进展

简述了由硫酸盐还原菌（SRB）引起的微生物腐蚀（MIC）的机理，环境因素与SRB的协同效应对MIC的影响及控制SRB的措施的研究进展。     

基于MapReduce的MIC算法并行化

MIC是一种分析变量之间可能存在的关系的方法。该方法不仅能够有效识别出变量间各种复杂类型的关系,还能够准确描述噪音数据对存在关系的影响,对探索大数据集中变量之间的关系具有重要意义。针对该方法在处理包含大量变量的数据集时性能方面的不足,首次对它进行了基于MapReduce模型的并行化。提出的并行化方法首先对原算法进行更细颗粒度的划分,然后采用一种基于Map-Reduce-Map任务链的并行模型,该模型不仅有效地增加了并行的计算单元,还大大地降低了不必要的系统开销。最后,通过理论分析和实验验证得出,改进后的算法与原算法相比,在准确率方面具有等效性,运行速度大幅度提升且具有良好的可扩展性;实验同时指出了算法性能的提升与系统资源的关系。     

基于PXI总线的MIC总线通讯控制器模块的设计与实现

MIC总线是专门为解决在恶劣环境下电力/数据的分配和管理而开发的一种具有高可靠性的现场控制总线,根据某型装甲车辆车电系统的测试要求,对MIC总线通讯功能进行测试,完成车电系统的故障诊断;根据测试要求,设计了一整套的测试系统,该模块为其中的一部分,通过对模块的硬件结构和软件两方面进行了分析,实现了基于PXI总线的MIC总线控制器的数据通讯设计;经过用户一段时间的严格测试,结果表明该模块完全符合MIC总线标准要求,性能稳定可靠,达到设计要求。     

MIC异构直线加速器束流动力学模拟并行软件开发

现代高能物理研究需要使用高能量的粒子加速器,加速器束流动力学模拟软件具有重要的实用意义. 介绍了一个3维基于MIC的异构直线加速器并行束流动力学模拟软件NEWBEAM-MIC的开发进展. 目的是使用最新的超级异构计算机提高束流动力学模拟软件的性能,更好地完成加速器的设计和优化工作. 这个软件模拟了DTL和SOLENOID加速器装置中粒子的运动过程. NEWBEAM-MIC是在NEWBEAM-CPU软件基础上,将粒子推进部分分配到MIC卡上运行,从而利用MIC多线程的优势使计算加速的. 通过实际测试,这个软件在天河二号上使用100 CPUs和100 MICs可以模拟10⁹个粒子,其中DTL场力计算、SOLENOID场力计算和粒子推进三个部分均可以比仅使用100 CPUs的NEWBEAM软件有100倍以上的加速效果. 再考虑MIC卡上的多线程,对同样规模的粒子,使用100 CPUs 和 100 MICs,当MIC线程数开到最大（224）时,NEWBEAM-MIC可以比单线程串行计算方式加速10000倍以上. 这表明本文开发的基于MIC的异构软件可以很好地加速原有的CPU软件,发挥现有MIC异构超级计算机的潜在性能.     

The interaction of bacteria and metal surfaces

This review discusses different examples for the interaction of bacteria and metal surfaces based on work reported previously by various authors and work performed by the author with colleagues at other institutions and with his graduate students at CEEL. Traditionally it has been assumed that the interaction of bacteria with metal surfaces always causes increased corrosion rates (“microbiologically influenced corrosion” (MIC)). However, more recently it has been observed that many bacteria can reduce corrosion rates of different metals and alloys in many corrosive environments. For example, it has been found that certain strains of Shewanella can prevent pitting of Al 2024 in artificial seawater, tarnishing of brass and rusting of mild steel. It has been observed that corrosion started again when the biofilm was killed by adding antibiotics. The mechanism of corrosion protection seems to be different for different bacteria since it has been found that the corrosion potential E_corr became more negative in the presence of Shewanella ana and algae, but more positive in the presence of Bacillus subtilis. These findings have been used in an initial study of the bacterial battery in which Shewanella oneidensis MR-1 was added to a cell containing Al 2024 and Cu in a growth medium. It was found that the power output of this cell continuously increased with time. In the microbial fuel cell (MFC) bacteria oxidize the fuel and transfer electrons directly to the anode. In initial studies EIS has been used to characterize the anode, cathode and membrane properties for different operating conditions of a MFC that contained Shewanella oneidensis MR-1. Cell voltage (V)—current density (i) curves were obtained using potentiodynamic sweeps. The current output of a MFC has been monitored for different experimental conditions.     

钢铁企业CIM S 的核心技术——M IC

MIC技术是钢铁企业CIMS的核心技术之一．介绍了MIC技术的产生背景与构成，论述了MIC系统与产品制造、质量设计与保证的关系，以及对企业产销全过程的能动作用。     

几种新型Schiff碱及其稀土配合物抑菌活性的研究

采用琼脂稀释法测定了几种新型Schiff碱及其稀土配合物对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌的抑菌活性,测得了它们抑制细菌生长的最小浓度。结果表明几种新型Schiff碱及其稀土配合物对几种受试菌均有较强的抑制作用,配合物比相应配体具有更高的抑菌活性。