Cobalt (Co) has been considered as one of the candidates for the barrier material in copper (Cu) interconnects. As a metal that is less noble than copper, Co poses two challenges to the integration scheme. For example, during the post-chemical mechanical planarization (CMP) cleaning step, corrosion of Co and galvanic corrosion between Co and Cu may occur. To minimize such corrosion, a corrosion inhibitor is often added into the post-CMP cleaning solution. The present study investigates the interaction between these metals and a representative corrosion inhibitor 1,2,4-triazole (TAZ). More specifically, this study uses various analytical techniques to elucidate the mechanism with which TAZ reduces the corrosion density of Co and Cu and prevents galvanic corrosion between the two metals. Furthermore, it is found that TAZ preferentially forms a passivating film on the relative stable Co surface containing cobalt hydroxide (Co(OH) 2 ) whereas the instability of Co reduces the effectiveness of TAZ inhibition. The corrosion protection for cobalt at pH 10 in presence of TAZ is mainly attributed to the physisorption and chemisorption of TAZ molecules on oxide covered Co surface, which follows Langmuir adsorption isotherm. It is anticipated that the same passivation mechanism may also be applicable to other structurally similar corrosion inhibitors.

We report a novel three-dimensional nitrogen containing carbon foam/silicon (CFS) composite as potential material for lithium ion battery anodes. Carbon foams were prepared by direct carbonization of low cost, commercially available melamine formaldehyde (MF, Basotect) foam precursors. The carbon foams thus obtained display a three-dimensional interconnected macroporous network structure with good electrical conductivity (0.07 S/cm). Binder free CFS composites used for electrodes were prepared by immersing the as-fabricated carbon foam into silicon nanoparticles dispersed in ethanol followed by solvent evaporation and secondary pyrolysis. In order to substantiate this new approach, preliminary electrochemical testing has been done. The first results on CFS electrodes demonstrated initial capacity of 1668 mAh/g with 75% capacity retention after 30 cycles of subsequent charging and discharging. In order to further enhance the electrochemical performance, silicon nanoparticles were additionally coated with a nitrogen containing carbon layer derived from codeposited poly(acrylonitrile). These carbon coated CFS electrodes demonstrated even higher performance with an initial capacity of 2100 mAh/g with 92% capacity retention after 30 cycles of subsequent charging and discharging.

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In this study, homologous cloning coupled with the rapid amplification of cDNA ends was used to clone a full-length cytosolic heat shock protein 70 of Ulva pertusa (designated as UPHsp70). Bioinformatics was used to analyze structural features, homologous relationship, and phylogenetic position of UPHsp70. The full length of UPHsp70 cDNA was 2,283 bp, with a 5′ untranslated region of 65 bp, a 3′ untranslated region of 247 bp, and an open reading frame of 1,971 bp encoding a polypeptide of 656 amino acids with an estimated molecular weight of 71.13 kDa and an estimated isoelectric point of 5.04. The UPHsp70 had four degenerate repeats of tetrapeptide GGMP and three typical Hsp70 signature motifs. The specific C-terminus amino acid sequence of cytosolic UPHsp70 was EEVD, and the conservation of Hsp70s of N-terminus was higher than that of C-terminus. The homology between UPHsp70 and Hsp70s of other known algae and land plants was more than 70%. Under different stress conditions, mRNA expression levels of UPHsp70 were quantified by quantitative reverse transcriptasepolymerase chain reaction. When U. pertusa samples were kept in different temperatures (5-40°C) for 1 h, the expression level of UPHsp70 at 5°C, 35°C, or 40°C was over onefold higher than that at 25°C. When U. pertusa samples were kept at 30°C for different times (0-12 h), the mRNA expression level of UPHsp70 had a trend of rise first then fall. The expression level of UPHsp70 reached maximum level after 5 h. When U. pertusa samples were kept in different salt concentrations (0-45‰) for 2 h, the expression level of UPHsp70 at 0‰ or 5‰ salt concentration was twofold higher than that at 30‰ for 2 h. The expression levels of UPHsp70 at 30‰, 35‰, and 40‰ were low and had no difference (P<0.05). When U. pertusa samples were kept at ultraviolet irradiation or desiccated for different times (0-4 h), the mRNA expression level of UPHsp70 reached maximum level after 3.0 h; after that, it was maintained at high level.