Abstract: Orthogonal testing method was used to study the effects of polystyrene particles, hydrophobic agent, air-entraining agent, polypropylene monofilament fiber on dry density, compressive strength, water absorption and softening coefficient of composite insulation mortar. The optimal ratio was obtained as: 3% of the weight are polystyrene particles, 0.2% is hydrophobic agent, air-entraining agent counts for 0.4wt%，and polypropylene monofilament fiber 0.6%. The main performances of the mortar were recorded as: dry density was 228Kg/m3, 28 day compressive strength after conserved for 28 days was 0.54MPa, and thermal conductivity 0.0596W/(m•K). Microstructure of the composite insulation mortar was analyzed by SEM (scanning electron microscopy) and its function mechanism was studied preliminarily.
Abstract: Orthogonal testing method was used to study the effects of fly ash, aggregate, weight ratio of water and material, way of incorporation of hydrophobic agent, on dry density, compressive strength, water absorption and softening coefficient of composite insulation mortar. The optimal ratio was obtained as 15% of the total weight is fly ash, 40% of the weight are aggregate, weight ratio of water and material are 1.1, 0.2% is hydrophobic agent (hydrophobic agent was added in the mixture). The main performances of the mortar were recorded as dry density was 220Kg/m3, compressive strength after 28 days was 0.50MPa, and thermal conductivity 0.0593W/(m•K). Microstructure of the composite insulation mortar was analyzed by SEM (scanning electron microscopy) and its function mechanism was studied preliminarily.
Abstract: Mg-doped LaFeO3 thin film and Mg, Cr-doped La0.5Sr0.5FeO3 thin films were prepared by the sol-gel method. The change rules of structure and dielectric properties of the films were studied by XRD, SEM, and Agilent. The dielectric properties of La0.5Sr0.5FeO3 and LaFeO3 films were improved by the substitute with Mg and Cr. The doping amount of Mg and Cr for the optimal dielectric properties of La0.5Sr0.5FeO3 films is 45mol%, 25mol%, respectively, and for LaFeO3, the doping amount of Mg is 8mol%. The observed pure perovskite phase of the doped films suggested the dissolution of Mn, Co, and Ni in La0.5Sr0.5FeO3 crystal lattice. Mg and Cr were integrate in the lattice of LaFeO3 and La0.5Sr0.5FeO3, and mineral is single perovskite phase. The surface of the film is smooth, without cracks, surface grain size distribution and had uniform grain size.
Abstract: Morphotropic phase boundary (MPB) composition, KNaNbO3-0.052LiSbO3(KNN-LS) was synthesized by sol-gel method at this experiment. Sb2O3 was used as economic Sb source and the final dried gel was calcined at 650°C for 2h to obtain white nanopowder. The sintering experiment was carried out at the temperature range of 980°C-1130°C, and perovskite phase structure could be observed apparently below 1080°C. When the temperature reached 1080°C and above, the second phase Na3LiNb6O17 appeared meanwhile the piezoelectric coefficient (d33) decreased quickly. Its proven that fine-grained particles and low sintering temperature could be obtained in sol-gel route.
Abstract: A S-containing additive, sulfuration modified soybean oil (named as SSO), was prepared by chemical modification of soybean oil with sulfur compounds. The friction and wear performances of AZ91D magnesium alloy against GCr15 bearing steel under the lubrication of rapeseed oil formulated with SSO were evaluated on a SRV tribotester. The topographies and the chemical species of the worn surfaces of magnesium alloy were analyzed by a scanning electron microscope (SEM) and an X-ray photoelectron spectroscope (XPS), respectively. The results indicated that the friction and wear of the magnesium alloy-steel tribomates could be effectively reduced by formulating SSO into rapeseed oil lubricant. The friction coefficients and the wear volumes of magnesium alloy decreased with increasing contents of SSO. The surface lubricated with SSO-doped rapeseed oil was characterized by less wear as compared with that lubricated with neat rapeseed oil. The enhanced anti-wear and friction-reducing abilities of rapeseed oil by SSO in the lubrication of magnesium alloy against steel were ascribed to the formation of a composite boundary lubrication film due to the strong adsorption of SSO and rapeseed oil onto the lubricated surfaces and their tribochemical reactions with magnesium alloy.
Abstract: By AF1100-type EDM machine, graphite rod as a tool electrode, misted deionized water mixed with fine-grained C powder as working medium, the strengthening coating was prepared on the surface of TC4 titanium. The surface microstructure of strengthening layer was observed, the hardness and thickness of strengthening layer was tested, under different peak current, pulse duration, pulse interval and polarity. The results show that: At a current of 2.9A to 6.6A when using negative polarity to strengthen can get better strengthening layer organizational.
Abstract: In order to resolve the problem of hoarfrost in red mud, prepare a geopolymer with sintered red mud and calcined bauxite tailings and fly ash and lime and gypsum. In the geopolymer, sintered red mud is 30%, gypsum 10%, calcined bauxite tailings and fly ash and lime 20% respectively. The compress strength of the geopolymer is 15.438MPa, as strength as a brick. It is a useful construction material for building road and filling stope and so on.
Abstract: It is the premise and foundation of numerical simulation to build models, because the optimal initial configuration of models can reduce the time of optimization and relaxation, and the ideal simulation results can be obtained. Nevertheless, as far as beginners are concerned, non interface operation of the LAMMPS system makes them more difficult to learn and manipulate, so they have no choice but to study the manual over and over again. Well, at least spend far too long in learning manual on account of less corresponding resources. Firstly, the basic concepts were presented in the paper such as lattice, unit cell, primitive cell, basis vector and lattice constant of crystal. Furthermore, what should be considered when compiling the LAMMPS script of lattice was described. Considering graphene, as material science and other areas of research focus at present, its lattice scripts were compiled respectively in the paper, including different chiralities of zigzag and armchair, different stacking ways of AA and AB. finally, the monolayer graphene models lattice structure of 2×2 and bilayer graphene models lattice structure of 2×2×2 were showed respectively using the VMD visual software, and this will provide beginners with a variety of ideas in modeling.
Abstract: The better appearance of LCD rare earth polishing powder, the better sales. High-performance polishing powder for LCD was synthesized by using NH4HCO3 subsidence method, with rare earth carbonate as starting material. Coloring mechanism of rare earth polishing powder was studied by using TGA, XRD and so on. Color of rare earth polishing powder was quantitative described with the values of L, a, b, R, and chemical composition had a great influence on it. The result showed that Ca, Mg, Zn, Mn, P, Fe, Cu had a great effect on the white color of rare earth polishing powder, and the color had regular changes with chemical composition, calcining temperature, calcining time. The result can control production of rare earth polishing powder based its color, and it has significant practical value to color control of rare earth polishing powder.