Corrosion behavior of low alloy steels in a wet–dry acid humid environment

The corrosion behavior of corrosion resistant steel (CRS) in a simulated wet–dry acid humid environment was investigated and compared with carbon steel (CS) using corrosion loss, polarization curves, X-ray diffraction (XRD), scanning electron microscopy (SEM), electron probe micro-analysis (EPMA), N₂ adsorption, and X-ray photoelectron spectroscopy (XPS). The results show that the corrosion kinetics of both steels were closely related to the composition and compactness of the rust, and the electrochemical properties of rusted steel. Small amounts of Cu, Cr, and Ni in CRS increased the amount of amorphous phases and decreased the content of γ-FeOOH in the rust, resulting in higher compactness and electrochemical stability of the CRS rust. The elements Cu, Cr, and Ni were uniformly distributed in the CRS rust and formed CuFeO₂, Cu₂O, CrOOH, NiFe₂O₄, and Ni₂O₃, which enhanced the corrosion resistance of CRS in the wet–dry acid humid environment.     

铝阳极极化特性研究

分别测量了在阻挡型和多孔型电解质溶液中,铝阳极的恒电压和恒电流极化曲线.根据铝阳极极化曲线的特点,讨论铝在阳极氧化过程中有关阻挡层的形成、部分溶解,以及转化为多孔层等过程与极化电压和电流的关系.提出了在低极化电压或电流下,孔胚按“慢少成孔”机理在高极化电压或电流下按“快多成孔”机理的观点.     

高速光纤通信系统中PMD的特性分析

文章从理论上分析了高速光纤通信系统中PMD的特性,得出了由PMD导致的DGD(差分群时延)的机理。由于PMD是一个随机量而难以计算、测定,因而从谱域上给出了一种简单易行的测定PMD的实验方法。通过统计学分析法给出了输入脉冲宽度、输出脉冲宽度与系统PMD之间的关系。这种关系对于实际系统输入脉冲宽度的选择有理论指导意义。     

用埋设的微型探测器监测不同性能混凝土内的钢筋腐蚀

为了评估钢筋在不同性能的混凝土内的腐蚀程度,腐蚀程度和导致腐蚀的环境,做了一个试验,在试验中使用了微型探测器,将它们贴着钢筋埋设在混凝土内,用它们来测出三种电化学特性值：自然电位;极化电阻和电解质电阻。     

TES电话地球站交叉极化干扰分析

对云南ＴＥＳ 电话地球站交叉极化干扰的产生及影响进行了测试分析,得出卫星链路中交叉极化干扰对载噪比的影响程度的分析计算法．并应用于实际系统中．     

Anomalous dielectric behavior in nanocrystalline γ-Fe_2O_3

The measurements of electric capacities and dielectric loss angles for nanocrystalline γ-Fe₂O₃, under air and vacuum atmospheres have been conducted by using ac LRC method, and the conductivity and the polarization relaxation time have also been calculated from the frequency spectra of real and imaginary parts of the dielectric constants. The anomalous dielectric behavior implies the existence of two kinds of polarization mechanisms with different relaxation times, which are caused by the defects and the dangling bonds in the interfaces, respectively. The experimental and calculated results indicated that the polarization loss and the conductance loss are dominant in air atmosphere and vacuum, respectively.     

关于浓硫酸和稀硫酸氧化性的探讨

用离子极化的观点阐明浓硫酸具有强氧化性的原因,同时指出稀硫酸变具有氧化性,在此基础上,分析了浓稀硫酸氧化性的不同。     

韩国企业集团危机的内在原因及教训

韩国的大企业集团曾经是创造“汉江奇迹”的功臣,如今却陷入举步维艰的困境,韩国企业集团破产的原因有国际大环境的影响,但更主要的是韩国经济自存存在的问题,我国现在正处于经济转轨时期,国有大中型企业正面临状战略性改组,认识和研究韩国企业集团破产的原因很有启示。     

信杂比极化散射矩阵的优化

该文讨论了在回波信号及杂波的琼斯极化散射矩阵对称及非对称的情况下,调整天线的发射和接收极化状态,从而得到最大的回波信杂比。在前人工作的基础上推导出一种简单易行的算法,成功地实现了琼斯极化散射矩阵从不对称向对称的转变,并进行了数字仿真,结果验证了该算法的有效性。     

光纤的极化色散

由于应力的各向异性和纤芯的非理想圆将会引起极化色散。本文从介电常数微扰理论得到极化色散与波长的关系。