Study of the adsorption process of bovine serum albumin on passivated surfaces of CoCrMo biomedical alloy

Adsorption of bovine serum albumin (BSA) on CoCrMo surface was studied by electrochemical techniques in order to determine the mechanism of protein adsorption at different surface conditions (which are reached by considering different passivation times) in phosphate buffered solution (PBS). At open circuit potential (OCP), adsorption kinetic was influenced by surface passivation when passivation time was lower than 1 h, whereas, at higher passivation times, no apparent modification in the kinetic mechanisms of adsorption was observed. On the other hand, at a passive applied potential, the BSA addition decreased the passivation kinetics of the process at all the passivation times.     

Factors influencing electrode potential of steel in concrete

Abstract

An investigation of the rusting of steel wire in concrete and mortar is reported. Steel corrosion was monitored using electrode potential measurements, and five experimental parameters were controlled: cement type, mortar porosity, mortar cover thickness, mortar cracking, and carbonation thickness. Measurements were made by connecting the reference electrode to three locations on each face of every reinforced mortar parallelepiped sample. The results showed that the mean value of the electrode potential for a sample is correlated with the degree of rusting of the steel, although the location of the measurement does have some effect on the recorded electrode potential. Cracking of the mortar has also been shown to influence the electrode potential.     

单晶硅太阳能电池的背场钝化技术研究

太阳能的应用是解决能源与环境问题的有效途径,而高转换效率低成本,易于产业化的高效电池技术是太阳电池发展的目标。近年来高转换效率技术层出不穷,例如SE电池(Selective emitter Cell),MWT电池(Metal warp through cell)和EWT电池(Emitter Warp through cell)等。这些高效电池均采用了良好的钝化技术。而常规晶硅太阳电池由于没有采用背场钝化技术,只使用铝背场,而经过烧结形成的铝硅合金背表面在减少复合和背反射效果方面有很大的局限性,并且铝硅合金区本身即高复合区,限制了电池效率的进一步提高。因此为了进一步提高开路电压及短路电流,对硅基背表面进行钝化是很有必要的。通过试验,着重比较了SiNx背场钝化层和SiO2背场钝化层对电池电性参数的影响和变化趋势。通过对电池片IQE分析发现,在使用了SiO2或SiNx背场钝化层后,长波区域的IQE响应相比正常电池片有明显提升,说明SiO2或SiNx确实起到钝化作用。而再对电性参数分析后发现,SiO2与SiNx相比可以有效提高电池的Rsh,降低反向电流。同时在EFF测试方面,SiO2与SiNx相比,也具有一定的优势。     

光导型碲镉汞探测器的氢化研究

为了提高碲镉汞红外探测器的性能,对ZnS钝化的碲镉汞光导型探测器进行了氢化处理研究,发现处理效果与氢等离子体密度和ZnS钝化层的厚度密切相关。对于ZnS层厚度固定的器件,通过改变氢等离子体密度发现低等离子体密度条件氢化处理更有利于提高器件的性能,表现在处理后器件响应信号提高且噪声下降,从光谱响应上表现为器件短波方向的响应抬高;对于同样的氢化处理条件,通过改变ZnS钝化层的厚度,发现具有较大厚度ZnS层的器件的氢化效果更好。SIMS测试发现氢化过程中氢离子可以穿过ZnS层到达ZnS与碲镉汞的界面处,分析认为氢离子对界面态起到了钝化作用,降低了界面态密度,提高了器件的性能。     

Passivation of cobalt nanocluster assembled thin films with hydrogen

The effect of hydrogen passivation on bare and Pd capped cobalt nanocluster assembled thin films was studied with Rutherford backscattering spectrometry (RBS) and magnetic force microscopy (MFM) after exposure to ambient conditions. The nanoclusters are produced in a laser vaporization cluster source in which the helium carrier gas was mixed with hydrogen. RBS revealed that oxidation of the Co nanoclusters is considerably reduced by the presence of hydrogen during cluster formation. The capping did not modify the influence of the passivation. The hydrogen passivation method is especially effective in cases when capping of the films is not desirable, for example for magnetic studies. Clear differences in the magnetic domain structures between hydrogen passivated and non-passivated Co nanocluster films were demonstrated by MFM and are attributed to a difference in inter-cluster magnetic interaction, which is critically depending on the CoO content. The hydrogen passivation method may be used to tailor and stabilize properties of nanocluster assembled thin films.     

新型与普通镀锌钝化工艺效果对比分析

与原工艺相比,采用镀锌钝化新工艺后,不但提高了防腐性能,而且减少了有毒物质六价铬的使用和排放,从而减轻了对人类健康和环境的危害。     

镀锌钢丝的钝化工艺研究

本文描述了镀锌钢丝在铬酸盐钝化液中的成膜机理，研究了硫酸根离子、铬酸浓度、ｐＨ值、金属离子以及温度等在钝化成膜过程中的作用和影响。镀锌钢丝在钝化前经弱酸初光可增加钝化膜的光变性和牢固性。钝化后立即在适当温度下烘干即或以提高钝化膜的牢固性又可以提高耐腐能力。根据研究结果制定出较合理的工艺多数。     

用XPS研究Na_2S钝化的GaAs(100)表面

本文用Na_2S·9H_2O的水溶液及乙醇和异丙醇溶液对GaAs表面进行了钝化处理;用X射线光电子能谱仪(XPS)对钝化表面的化学组成和价态以及钝化层的厚度进行了研究。结果表明,经不同的Na_2S溶液处理后GaAs表面的自然氧化层会被除去,表面生成硫化镓和硫化砷;硫化物的含量与硫化层厚度与所用溶液的极性有关;并对钝化机理进行了探讨。     

粉煤灰对地铁杂散电流的抑制作用

本文阐述了地铁轨枕等杂散电流的截流子性质,以及在混凝土中掺加粉煤灰对地铁等杂散电流腐蚀的抑制作用,机理,杂散电流作为离子流,它能破坏钢筋的表面钝化膜,促进钢筋的锈蚀,在混凝土中的掺用粉煤灰抑制了钢筋表面钝化膜的破坏,从而降低了钢筋的杂散电流腐蚀。     

黄铜药筒低铬至无铬钝化工艺技术研究

介绍了黄铜药筒低铬至无铬钝化的工艺研究过程,其中低铬钝化工艺技术、超低铬钝化工艺技术、单宁酸协同缓蚀剂钝化配合微铬封闭工艺技术、防变色剂钝化工艺技术均能满足产品要求。北方华安工业集团有限公司采用的一种微铬钝化的工艺———单宁酸协同缓蚀剂钝化,封闭液铬酸酐含量小于1g/L,已应用在黄铜药筒的钝化生产上,从而结束了黄铜制品高浓度铬酸酐钝化的历史,污水处理成本低,既降低了生产成本,又解决了高铬对水质的污染问题,对节能减排、节约降耗具有显著的经济效益和社会效益。