Search

A BiVO4/TiO2 nanotube composite film was fabricated by anodization and low temperature solvothermal reaction for photocathodic protection. The results showed that after modifying the TiO2 nanotube film with BiVO4 nanoparticles, the light absorption of the BiVO4/TiO2 composite film was extended to the visible region. The photocurrent density of the composite film reached 271 μA cm−2, and was 8.5 times higher than that of the TiO2 film. Under white light irradiation, the composite film made the potential of the coupled 403 stainless steel in a 0.5 M NaCl solution drop by 520 mV, showing an effective photocathodic protection effect.

In this paper, precipitation of ScAl3 phase during solutionizing and ageing and its impact to mechanical properties of hypoeutectic Al-Sc alloy and effect of Sc addition amount were investigated by TEM and SEM microstructure observation and mechanical property testing. During solutionizing at 640oC for 24h, for Al-0.2wt.%Sc and Al-0.4wt.%Sc alloy, ScAl3 particles formed in the course of solidification become smaller, indicating, as a whole, Sc is partially dissolved into Al solution. Simultaneously, precipitation of two types of ScAl3 particles are observed by TEM. One has a size of 200~300nm, and the other is much small, 5~20nm in size. Though re-dissolution of Sc solute into Al solution and precipitation of large and fine ScAl3 particles occur in the solutionizing course, but the strength and hardness are decreased. The key reason for it is thought to be the softening effect of high level of vacancies in matrix lattice from the high solutionizing temperature. After further aging at 300oC for 3h, a great number of fine ScAl3 particles are precipitated in the Al matrix, which leads to a considerable precipitation hardening effect, thus the strength and hardness are increased obviously. Increasing the Sc content in the alloy results in a considerable rise in as-cast and as-aged strength and hardness, due to the solution strengthening and precipitation hardening respectively.

Treatment of dinitrodiazophenol (DDNP) industry wastewater by combining Fe 0 /air and Fenton process was investigated to decompose the refractory pollutants (i.e., DDNP and its by-products) and improve the biodegradability. Two control experiment systems (i.e., Fe 0 /air system and Fenton system) were set up to confirm the synergistic reaction between Fe 0 /air and Fenton process. In addition, effect of initial pH (1.5–8.0), Fe 0 dosage (10–50 g/L), air aeration (0–2.0 L/min), treatment time and hydrogen peroxide (H 2 O 2 ) dosage (0–50 mmol/L) on the treatment efficiency of the combined process was studied, respectively. The results show that the maximum COD (78%) and chromaticity (98%) removal efficiencies were obtained under the optimal conditions. Meanwhile, BOD 5 /COD ratio was enhanced from 0 to 0.27, which suggest that its biodegradability was improved. Furthermore, DDNP concentration was detected by HPLC, and the degradation of DDNP industry wastewater was analyzed by UV–vis and Fourier transform infrared spectra (FTIR). The results suggest that DDNP removal efficiency reached 99.83%, and benzene-ring, nitro-group (NO 2 − ) and diazo ( N N ) of DDNP had been decomposed and transferred into the smaller molecules organic compounds. Therefore, a good treatment of DDNP industry wastewater could be obtained by the combined Fe 0 /air and Fenton process.

The apoptosis that occurs in the immature testis under physiological conditions is necessary for male germ cell development, whereas improper activation of apoptosis can impair spermatogenesis and cause defects in reproduction. We previously demonstrated that in mice, the makorin-2 (Mkrn 2) gene is expressed exclusively in the testis and its deletion leads to male infertility. To understand the potential molecular mechanism, in this study, we found that levels of apoptosis in the testis were abnormally high in the absence of Mkrn 2. To identify specific gene(s) involved, we performed digital gene expression profiling (DGE) and pathway analysis via gene set enrichment analysis (GSEA) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, and we found that MKRN2 inhibits p53 apoptosis effector related to PMP22 (PERP) expression and that levels of the protein in sperm samples have an inverse correlation with infertility levels. GSEA additionally indicated that PERP is a negative regulator of spermatogenesis and that its ectopic expression induces male infertility. Further, Gene Expression Omnibus (GEO) dataset analysis showed that p53, upstream of PERP, was upregulated in oligoasthenoteratozoospermia (OAT). These observations suggest that Mkrn 2 is crucial for protecting germ cells from excessive apoptosis and implicate Mkrn 2-based suppression of the p53/PERP signaling pathway in spermatogenesis and male fertility.