Advanced Materials Research Vol. 940

Abstract: This paper introduces a process that combines a vacuum expandable pattern casting V-EPC with self-propagation high–temperature synthesis SHS of TiB2/TiC particles for fabricating the TiB2/TiC duplex particulates reinforced carbon steel matrix surface composite, and the effect of relative thickness δ on metallurgical quality and microstructures. FeTi-FeB-FeCr system with low cost is adopted as the SHS reactant. Experimental results show that with increasing δ, the surface composite is gradually formed and the metallurgical quality improved. The typical microstructures of the composite from surface to core are consisted of three different layers, i.e., the surface compound layer, the interim transitional layer and the carbon steel base. A certain amount of fineTiB2/TiC particles is distributed in the matrix of the surface compound layer.

Abstract: Using the sodium citrate as ligands and adopting electric brush plating method, Re will be deposited together with Ni-P from the solution, and a complex brush plating of Ni-P-Re can be attained. It is discussed the effect of the rare earth Re3+ on the deposition rate, corrosion resistance and bonding strength of the Ni-P composite brush plating. Adding some appropriate Re3+ to the brush plating solution, the amorphous tissue can be obtained under the condition of the low phosphorus brush plating, which make the brush plating layer with high hardness and high abrasive resistance at the same time, binding force and corrosion resistance are improved, and greatly improve the performance of the brush plating.

Abstract: Zinc nitride films were deposited by ion sources-assisted magnetron sputtering with the use of Zn target (99.99% purity) on 7059 glass substrates. The films were characterized by XRD, SEM and EDS, the results of which show that the polycrystalline zinc nitride thin film can be grown on the glass substrates, the EDS spectrum confirmed the chemical composition of the films and the SEM images revealed that the zinc nitride thin films have a dense structure. Ultraviolet-visible-near infrared spectrophotometer was used to study the transmittance behaviors of zinc nitride thin films, which calculated the optical band gap by Davis Mott model. The results of the fluorescence emission spectra show the zinc nitride would be a direct band gap semiconductor material.

Abstract: Study on the effect of liquefaction mechanism on the performance of ECC, adding rubber powder mesh size effect on the performance of ECC, respectively, to 40 mesh, 60 mesh, 80 mesh and 100 orders at the same content of rubber powder and 40 mesh in different dosage on ECC compressive strength, flexural toughness was analyzed, results show that: the use of the mechanism of liquefaction of mixing rubber powder in cement based materials, with the increase of ECC number increased ductility, at the same time reduce the compressive strength is larger, rubber powder content in 12%, the comprehensive effect is ideal. The needle for fiber reinforced cement based materials and meticulous research component, has broad prospects in the repair of future building early warning and lane.

Abstract: The investigation of the catalytic behavior of a hydrophobic guest artificial glutathione peroxidase (GPx) (ADA-Te-ADA) was carried out employing H₂O₂ and 3-carboxyl-4-nitrobenzenethiolas (TNB) as substrates. The relation between the catalytic rate of ADA-Te-ADA and the property of solvent used in the determination of catalytic activity was revealed. Typically, the co-solvents including ethanol, DMSO, DMF and CH₃CN were employed in the determination of catalytic rates. It indicated that ADA-Te-ADA exhibited the typical solvent-dependent catalytic behavior. Especially, the higher catalytic rate was observed when polar protic solvent (ethanol) was used compared with other co-solvents. It suggested that polar protic solvent was the appropriate co-solvent for the assay of catalytic activity of hydrophobic artificial GPx. Additionally, the strong polarity of polar aprotic solvent plays an important role in the enhancement of GPx catalytic activity. This study bodes well for the understanding of the catalytic behavior of hydrophobic guest artificial GPx.

Abstract: A film of Ni-P-Carbon-nanotube composite material is deposited on the surface of the metal substances by electro-brush plating. In this process, the composition of the Ni-P-Carbon-nanotube composite plating solution, the pretreatment on the carbon-nanotube and the effects on quality by the different brush plating technology conditions are investigated. The results shows that carbon-nanotube particles can be distributed uniformly in the coating by oxidizing, sensitizing and activating while the temperature of the plating solution should be controlled at 55°C, and PH value, 1.5~2.5. After the carbon-nanotube is added, the coating defects, such as the crack, the desquamation and the low bond strength, can be prevent effectively.

Abstract: Al-Mg welding wires applied extensively in aluminum alloy welding field.5183 ingot and 5356 ingot added Sc, Zr and Er were fabricated by DC casting method and extruded into welding wire, furtherly. Surfacing layer on 7A52 aluminum alloy prepared by using automatic surfacing formation system. Optical microscopy (OM) and 1600-5122VD MICROMET 5104 micro-hardness tester utilized to observe microstructure of 5183 and 5356 ingots, to measure micro-hardness of surfacing layer fabricated by using 5183 and 5356 welding wire with Sc, Zr, Er addition, respectively. The results indicated that, owing to addition of rare earth element, re-crystallization of Al-Mg extruded ingot to generate welding wire was restrained markedly; Microstructure was refined obviously when Sc added; And average size of the grains was about 10μm. Micro-hardness of surfacing layer improved after addition of Sc, Zr, Er element in the ingots.

Abstract: The Separation of microcystin-RR from crude microcystin solution by HPLC was studied.The interception time could be decided by the combination of MC-RR peak time and 0.55min.0.5mL high purity MC-RR solution,with the concentration of 2.58μg/mL and recovery of 82.9%, was obtained by established method.The storge condition experiments showed that MC-RR stays stable in pH7 solution in 60 days.

Abstract: The solubility of TNT and RDX was measured in supercritical carbon dioxide fluid at 303.0, 308.0, 323.0, 338.0 K, and over the pressure range from 10.0 MPa to 50.0 MPa. This study examined the influences of extraction temperature, extraction pressure and support effect (SE) between molecules of TNT and RDX on their solubility in the TNT/RDX/SC-CO₂ system. The results show that solubility of TNT and RDX in TNT/RDX/SC-CO₂ ternary system is much higher than that in binary system. The values of SE of RDX and TNT increase first and decrease then with the pressure changing. The pressure turning point occurred over the pressure range from 25 MPa to 28 MPa for TNT and from 13 MPa to 20 MPa for RDX.