Advanced Materials Research Vol. 740

Abstract: Use the latest molecular ecology to parse the dynamic changes of microbial community in biofilm under a variety of influences, which further reveals microbiological processes in the nitrogen and phosphorus removal reactor, and has great significance to study in-depth simple, efficient, low consumption of nutrient removal technology and its theory. This article described the extraction of total DNA, PCR, DGGE and other common molecular ecology techniques, summarized researches at domestic and foreign, discussed the application prospects of molecular ecology techniques for study of microbial communities in biofilm.

Abstract: Bi₂O₃ Chaplet-like Nanoparticles have been fabricated. Most of them have the average inner diameter of 200nm and the mean rim thickness of 20nm. Photoluminescence spectra of the nanorings at room temperature were investigated, which demonstrated that the rings present excellent optical properties. The influence of aging time on the morphology and structure of β-Bi₂O₃ superstructures was also studied, indicating that the nanorings superstructures were transformed into nanoplates after a long aging time. The formation mechanism of the β-Bi₂O₃ superstructures was also explored. This approach will be further extended to solvent-controlled fabrication of related minerals with novel complex superstructures.

Abstract: Tumor necrosis factor-alpha converting enzyme (TACE) is a membrane-anchored protein that releases the soluble forms of many proteins by a process called ectodomain shedding. TACE has been considered as a potential target in a lot of diseases in autoimmune diseases and in cancers recently. In spite a lot of protein substrates have been found these years for TACE, the substrate selection of TACE is still not known. In this paper, a TACE-peptide complex was constructed, and used for the prediction of substrate sequences and cleavage sites. The result could be useful for understanding the substrate specificity of TACE, and designing better TACE inhibitors in future.

Abstract: As a new kind of seepage control material, the geomembrane has been widely used in earthrock dam, yet the seepage calculation of the geomembrane earthrock dam has not been studied on theory. Based on seepage mechanism in geomembrane, this thesis classifies the seepage into two types: one is permeability of geomembrane itself; the other is defect leakage flux in geomembrane. Based on feedback analysis of geomembrane earthrock dam with observation data, the permeability coefficient of geomembrane can be obtain on average, so the problem that the defects in geomembranes are difficult to ascertain is solved. At last, the sources of error in seepage calculation for geomembrane earthrock dams by method of clay equivalency were discussed. Analyzed the count error, and corrected the mathematical model.

Abstract: The current paper reported the sonichemical synthesis and optical properties of the Bi-doped ZnO with superstructural nanomaterials. The morphology of the powders revealed by SEM and TEM exhibited stelliform dendrite and the sonication time appeared to be a critical parameter for the shape determination. The optical properties of the products were investigated by measuring the photoluminescence spectra at room temperature and the results demonstrated that the synthesized material has good optical properties.

Abstract: This paper presents the dielectric barrier (PVC, PMMA, and glass) breakdown voltage test in transformer oil in uniform field, slight non-uniform field and highly non-uniform field generated by plate-plate, plate-point, and point-point electrodes, respectively. It was found that PVC can withstand the maximum breakdown voltage that is higher than PMMA and glass. The dielectric barrier with 1 mm thick placed next to the high voltage electrode and ground electrode can withstand the higher breakdown voltage than dielectric barrier with 2 mm thick placed next to the ground electrode and at the middle of electrodes. PVC for point-point, plate-point and plate-plate electrodes can withstand the maximum breakdown voltage of 216.5, 195.7 and 181 kV, respectively. The breakdown voltage of solid insulations is different because of the shape of electrode. These results lead to design the solid insulator in transformer oil under uniform and non-uniform electric fields.

Abstract: In this study, an attempt has been made to develop electroless Ni-P-ZrO₂ nanocomposite coatings on mild steel substrate where the reinforced nanosized ZrO₂ particles were prepared by mechanical milling using high energy planetary ball mill. An alkaline bath was used with a suspension of ZrO₂ particles (4 g/L) for the synthesis of Ni-P-ZrO₂ composite coating. The surface morphology, size range and phase analysis of as-prepared ZrO₂ particles were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and the properties of the coatings such as hardness and wear (ball-on-disc) were investigated and compared with Ni-P deposits. The results showed that as-prepared ZrO₂ particles exhibit irregular shaped and size ranges from 14 to 17nm. After heat treatment (400°C,1h), the microhardness and wear resistance of the coatings are significantly improved. The Ni-P-ZrO₂ nanocomposite coatings exhibit enhanced wear resistance over NiP coating.

Abstract: Novel organic-inorganic hybrid membranes of polymethyl methacrylate (PMMA) containing multi-walled carbon nanotubes (MWNTs) were successfully prepared. Then, the swelling adsorption experiments of benzene/cyclohexane mixtures were employed to evaluate the performance of these membranes. Via transmission electron microscopy (TEM), Fourier transform infrared spectrophotometry (FTIR), the effect of surface modification on the morphology and properties of carbon nanotubes and hybrid membranes were studied. The results indicated that the separation performance for benzene/cyclohexane of the hybrid membranes depended on both the polarity of carbon nanotubes and the distribution of MWNTs in PMMA. Because the dispersion of MWNTs were obviously improved after acidification and ammonization modification, the hybrid membranes including modified MWNTs showed higher performance than membranes with un-modified MWNTs. In addition, a large number of polar group were introduced in the MWNTs during modification of acidification and ammonization, which depressed obviously the physical adsorption of cyclohexane by MWNTs. Therefore, these two changes in the properties of MWNTs both improved the separation performance of hybrid membranes.

Abstract: This work presents a bio-degradable glass probes and its biocompatibility assessment for neural applications. The probes can be implanted into different sites of the human brain for recording and stimulating purposes. Current existing neural probe address the probe stiffness requirement for the penetration of brain tissue. However, this requirement normally resulted in the rigidity of the probe which is non-compatible with the brain tissue movement for long term implantation. The brain neuron cells will be damaged by too rigid probe substrate. In order to address this issue, bio-degradable glass probes having sufficient stiffness for a smooth brain insertion as well as ability to degrade after implantation; leaving behind the flexible circuitry substrate was being explored. The biodegradability of the proposed probe was evaluated.

Abstract: This paper, through UV-vis absorption spectra of iron porphyrin chloride, fluorescence-emission spectra of NaOH and of DMSO, has obtained the properties of iron porphyrin chloride, and has made verification and comparison through molecular simulation method. Verification and comparison result coincide well, and this paper has made explanation to it.