Applied Mechanics and Materials Vols. 668-669

Abstract: Based on the multi-fractal theory and SEM image, the multi-fractal property of the plant abrasive to metal surface was studied. The result shows that the characteristic parameters of △α and △f of the multi-fractal spectrum on can reflect the morphology features of the worn surface, which are connected with volume wear, so they are regarded as characterization parameters in quantification on the surface of metallic material that is worn by plant abrasive. 15 mm.

Abstract: One sol-gel method is explored to prepare red, green and blue (RGB) fluorescent dyes co-doped nanoporous silica at low temperature in air. All of the dyes covers blue-emitting 2, 5-bis (5-tert-butyl-2-benzoxazolyl)- thiophene (BBOT), green-emitting Coumarin 152A (Coumarin) and red-emitting Lumogen red R305 (Lumogen), contributing to the photoluminescence (PL) of the hybrid. As a key factor, the molar ratio of reactants TEOS/Dioxane/ H₂O is 3:12:4 during the sol-gel process. The maximum doping concentration of dyes is the result of dyes dispersing into nanoporous silica, which supported by Infrared Spectroscopy (IR) and X-ray diffraction (XRD) technology. So this sol-gel preparation can enrich the inorganic luminescent materials at a simple style, especially for PL materials or electroluminescent (EL) materials in thin films state.

Abstract: The microstructure of 40CrNi2Mo steel matrix strengthened with wear resistance alloy is observed by the optical scope, SEM with EDS and FESEM. Analysis emphasis is lied on the distribution regulation of nanosized WC particulates in the microstructure of the steel matrix. Experimental results show that the method of adding wear resistance alloy in steel matrix can avoid gravity segregation phenomenon effectively and guarantee a uniform distribution of WC in steel matrix. nanosized WC particulates distributing evenly in steel matrix improve the wear resistance, and make microstructure of the steel matrix more uniform, finer and denser proved by its high-expansion micrograph.

Abstract: Electrical discharge grinding is part of the most widely used methods to machine polycrystalline cubic boron nitride cutting tool. Polycrystalline cubic boron nitride compact samples processed in domestic with different grain size are the research object. Electrode running speed, peak current, and pulse width are selected as the main process parameters. The material removal volume and electrode loss set as the evaluation index of productive efficiency; workpiece surface roughness value sets as an evaluation standard of processing quality. Through electrical discharge grinding experiments, combined with scanning electron microscopy observation, energy spectrum analyzer and roughness tester, the influences of the main process parameters on electrical discharge grinding are analyzed, polycrystalline cubic boron nitride compact electrical discharge grinding technics & mechanism are summarized.

Abstract: Understanding rules of the distribution of fiber is important to control the mechanical properties of composite material performance. Fiber orientation in dumbbell-shaped injection cavity is different from that in regular cuboids because of its complex shape. Fiber orientation equation, Fokker - Planck equation was solved by the finite volume method and the errors brought by approximate method were avoided. The calculation results verified demonstrated that the shape of injection cavity affected the fiber orientation. In the flow direction, fiber of the shrinkage zone oriented along the flow direction and of the dilation zone oriented along tensile direction which is vertical to the flow. In cavity thickness direction, fiber orientation was layered.

Abstract: First-principles pseudopotential calculations have been performed to investigate the structural stability and electronic properties of magnesium considering three possible structures under high pressure. The results show that magnesium crystallizes in the hcp structure is to be the most stable structure at the ground state, because of the lowest total energy. Magnesium undergoes a pressure-induced phase transition from the hcp structure to bcc structure at 65 GPa. And no further transition is found up to 220 GPa. The electronic structure properties of three structures of magnesium are also calculated and discussed. The structural stability mechanism is also explained through the electronic structures of three phases.

Abstract: A large number of ceramic insulators that are widely used in the power systems are returning shipment every year but there is no better processing method. Silicone rubber insulators have highly required the additive of the formulation. So this article combining the advantages of ceramic insulators and chemical composition, studies the mechanical properties of ceramics modified composite insulator materials. The measurements include the tensile strength, tear strength, hardness, SEM and Fourier transform infrared spectroscopy test of the new silicone rubber. The effects of adding different proportions of ceramic powder on the mechanical properties of silicone rubber are compared. And from the microscopic analysis the mechanism of the improved properties of the modified silicone rubber is analyzed. The results showed that a proportion of the ceramic part can replace aluminum hydroxide powder and the fumed silica powder can significantly improve the mechanical properties of the silicone rubber.

Abstract: The present work studied the critical control of foam insulation materials produced by waste TFT-LCD glass. The result showed that foam glass was affected by sintering temperature, as well as other factors such as foaming agent, oxygen supply agent and reaction time. The ordinary waste glass was used to drop the melting temperature of Waste TFT-LCD glass. The density of foam glass had a down-up trend with the increase of sintering temperature. The increase of ratio of foaming agent and oxygen supply agent led to a notable decrease of the density, while the change of reaction time exerted an unobvious influence on the density. The density of foam glass produced under the optimal conditions was 0.2211 g/cm³.

Abstract: A carboxyl functional cholesterylated compound for hepatic targeting liposome ligand T₁ was synthesized. Cholesterol as starting material, after esterification with p-toluenesulfonyl chloride to get cholesterol tosylate M₄, then etherification with tetraethylene glycol to get hydroxyl functional M₃, M₃ react react with methanesulfonyl chloride to get M_2, M₂ was elongated by reaction with PEG2000 to get M₁ and M₁ react with succine anhydride get T_1. The target compounds afford cholesterylated hepatic targeting liposome ligands.

Abstract: Regular researches of system Sn-Pb alloys with use AE are carried out in various crystallization conditions. In the given researches the technique has been used, which allow to divide the signals radiated with plastic deformation and crack's formation and development from each process. In the metals and alloys majority radiation of AE signals begins in the middle of crystallization's area and comes to an end at the moment of the crystallization termination However in a number of materials AE signals have been registered below an excess point on a cooling curve in a firm condition. Essential influence of small impurity on AE feature and is revealed at crystallization AE character with crystallization of pure metals is defined by a kind of a crystal lattice. Linear dependence total AE from cooling rate is established Influence of superfluous and low residual pressure on AE character established with crystallization.