Abstract: Zr-Al-Ca-O-N composites were prepared in N2 atmosphere at 1600 oC with Ca-PSZ and AlN powders as raw materials. Zr-Al-Ca-O phase was synthesized in air atmosphere at 1600 oC with Al2O3, ZrO2 and CaO powders as raw materials. Phase constitution of these composites was investigated by XRD and EDS analyses. The results show that Zr-Al-Ca-O phase exists in Al-CaO-ZrO2-N2 systems ceramic and Zr-Al-Ca-O phase can be synthesized in air atmosphere at high temperature with Al2O3, ZrO2 and CaO powders as raw materials.
Abstract: The performance and behavior of epoxy latex coatings are different from solvent-type ones.It is decided by the distinct curing mechanism. The solvent-type epoxy film obtained from epoxy resin and curing agent by homogeneous reaction, namely, the state of epoxy resin and curing agent is uniform. However, epoxy latex film made from epoxy resin emulsion or dispersion and water soluble amine by polyphase reaction. So the determination of potlife of epoxy latex can be showed by film gloss changes with residence time, dissimilar with solvent-type by the index of viscosity. The modern infrared spectrum measure shows that the epoxy groups in the dried epoxy latex film exist even if EEW to HAV proportion is 1.2:1. This also testifies the incomplete polyphase reaction mechanism of epoxy emulsion coating curing at ambient temperature.
Abstract: The reaction of Propylene oxide(PO) ring-opening esterification was calculated by Gaussian03. The Density Function Theory (DFT) method was employed to study the geometries of PO and Maleic anhydride(MAH) reaction product obtained with the ethanol induced on the base of B3LYP/6-31G in the paper. The transitional states(Ts1,Ts2) of PO ring-opening esterification were found by TS method and were proved by IRC calculation. The results showed that from the reactant to product, the energy reduced about 799.07093 kJ/mol, The computation result showed that the reaction was exothermic.
Abstract: A kind of Carbon nanotube-implanted mesoporous carbon sphere (CNTs-MCS) is successfully prepared by a facile polymerization-induced colloid aggregation method using gelatin as a soft template. SEM, TEM, BET measurement and BJH method reveal that the obtained CNTs-MCS possess a mesoporous character, with specific surface area (284 m2•g-1) and uniform pore size of 3.9 nm. As the electrode material for supercapacitor in 6 mol•L-1 KOH, a low equivalent series resistance of 0.9 Ω cm2 and a maximum specific capacitance of 189 F•g-1 with a measured power density of 8 kW•kg-1 at energy density of 26.3 Wh•kg-1 are obtained.
Abstract: The differential scanning calorimetry(DSC) was used to study the curing reaction of low toxic UF resin with poplar, birch, larch powder in different pH value. The results showed that the effect of different wood flour and its pH value on the curing reaction of UF resin was not the same. Along with the increase of the pH, the peak temperature and the onset temperature was raised; the peak temperature and the onset temperature of poplar was higher than that of the birch. The tempera- ture of the curing reaction of UF resin modified by melamine was higher than the UF resin without modification.
Abstract: Visible-light-induced BiVO4-SiO2 composites photocatalysts with monoclinic scheelite structure were successfully synthesized via a sol-gel method, and were characterized with XRD, XPS, DRS, SEM and BET. The result indicated that BiVO4-SiO2 composite photocatalysts exhibited relatively high BET surface areas, consisting of primary nanocrystals with average size of 44 nm. The band gap of the sample was estimated to be 2.56 eV, representing an obvious blue-shift compared with that of the SSR-BiVO4 sample. The photocatalytic activities were also evaluated by decolorization of methylene blue (MB) under blue light. The photodegradation rate of BiVO4-SiO2 composite photocatalysts was quite high, up to 69% in 2 h, which was much better than that of the reference sample prepared by solid-state reaction (5.5%) under the same conditions.
Abstract: The copolymerization reaction between gomuti starch and acrylamide was initiated using (NH4)2S2O8 as initiator under microwaves heating at 60~80 . The analysis of the Fourier transform-infrared spectroscopy and Scanning electron microscopy showed that the product is gomuti-graft-polyacrylamide. The productivity of graft copolymer and the conversion rate of acrylamide vary with the weight ratio of acrylamide and gomuti starch (AM/GOM). They reach maximum value when AM/GOM≈2.5. The flocculating test showed that in water of yellow mud , the turbidity removal rate of gomuti-graft-polyacrylamide is better than that of polyacrylamide.
Abstract: This paper presents a high-performance rust converter whose formulation is based on polyphosphoric acid and tannic acid. In order to improve the performance of the product, active agent, catalytic agent, corrosion inhibitor, penetrating agent and wetting agent, etc., are added. Some results of accelerating experiment such as the A. C. impedance experiment are also presented, which demonstrate the high performance of the product. All ingredients in the product are cheap, easily accessible, and environment-friendly.
Abstract: The improved supercell plane wave expansion method is applied to theoretically study the propagation of flexural waves in a ternary locally resonant phononic crystal thin plate with a point defect and linear defects. The thin concrete plate composed of a square array of steel cylinders hemmed around by rubber is considered here. Absolute band gaps in low frequency are obtained. For the point defect, the defect mode is localized around the defect, and the magnitude of the resonant defect mode is strongly dependent on the defect filling fraction, mass density and Young’s modulus of the defect cylinder. For the straight linear defects, several resonant linear defect bands appear inside the absolute band gap. And the displacement distributions show that the flexural waves could well propagate along the linear defects.
Abstract: We set 7075 Al alloy as the object of study,expecting to optimize alloy formula and find the optimal dosage of rare earth in order to improve its mechanical properties by adding different percentages of the rare earth elements,the results show that:When the rare earth content reaches 0.3%,with the two-stage aging treatment,7075 Al alloy′s tensile strength comes to 420.76MPa and elongation comes to 16.80%.Compared with the exclusing rare earth group,7075 Al alloys′ tensile strength increased about 8.4% and elongation only falls by 2.3%, so the mechanical performance is the best.