Applied Mechanics and Materials Vols. 117-119

Abstract: In our study, a new kind of material for machine oil adsorption was prepared by melt blending with EPDM as the matrix and modified fly ash as the filler. The effects of dicumylperoxide (DCP) and modified fly ash contents on the machine oil absorbency were studied. The results show that the machine oil absorbency reaches the highest value 473.49% for the composite with 2 wt % DCP and 25 wt % modified fly ash. Comparing the machine oil absorbency for three samples, the experimental result indicates that the machine oil absorbency of modified fly ash /EPDM composite was higher than that of fly ash and modified fly ash.

Abstract: Boronized layer on silicon steel substrate was fabricated using pulse electrodeposition technique with different duty cycle in KCl-NaCl-NaF-Na₂B₄O₇ molten salts. The effect of the duty cycle on composition and microstructure of obtained layer was investigated. The boronized layer was analyzed by X-ray diffraction analysis (XRD), optical microscopy (OM), glow discharge spectrometry (GDS), and atomic force microscopy (AFM). The results showed that in the range of 10-50%, duty cycle almost had no effect on composition and thickness of the layer. The boronized layers in this range exhibited FeB phase on the surface of silicon steel. However, duty cycle had great effect on the microstructure of the boronized layer. A fine grain size boronized layer can be obtained at a duty cycle of 20%.

Abstract: A convenient method to synthesize starch/lactic acid copolymer was studied in this work. The lactic acid grafting starch copolymer was directly prepared by reaction of cornstarch with lactic acid catalyzed with stannous chloride (SnCl₂). The structure of starch/lactic acid copolymer was characterized by IR and 1H-NMR, and its morphology was seen by SEM and XRD. The effects of mass ratio between starch and lactic lacid, amount of catalyst and reaction time on the grafting degree were also studied. The result showed that the best grafting degree could reach 12.8％ with 1:6 as the mass ratio between starch and lactic acid and 1.5％ as amount of catalyst accounting for consumption of lactic acid by reaction at 90 oC for 7 h.

Abstract: This research is one part of preliminary work for integrated structural-functional energy storage concrete by using porous artificial lightweight aggregate and phase change material. Lightweight aggregate concrete (LWAC) has been applied more and more extensively in recent years, but high water absorption of porous artificial lightweight aggregate (LWA) is inconvenient for LWAC production. In order to improve LWA application, in this paper, two aspects of lightweight aggregate (LWA) study have been carried out, namely, a) LWA surface modification. The effects of different concentration of surface modifier on water absorption of modified LWA were studied. b) Mechanical properties of lightweight aggregate concrete made of the unmodified and modified LWAs Through comparing the water absorption of unmodified and modified LWAs, it can be known that the surface modification for LWA can reduce the water absorption obviously. The three kinds of lightweight concrete possess nearly same strength at 7-day and, at 28-day, the strength of LWAC using 1:20 modified LWA is highest and that of LWAC using 1:5 modified LWA is lowest. 28 days compressive strength of LWAC using 1:20 modified LWA could be up to 46.1MPa.

Abstract: Based on different aromatic dibromides and diamines, using Material Studio software and molecular simulation method, Poly(imino ketone) (PIK), Poly(imino ketone ketone) (PIKK), Poly(imino imino ketone) (PIIK), Poly(imino imino ketone ketone) (PIIKK), Flourene-PIIK and Naphthyl-PIIK, respectively, were designed as six different structures of polymers. And through the method of molecular mechanics and molecular dynamics the single-molecule polymer chain model and the aggregation-state model with three-dimensional periodic boundary conditions would be built. Theoretically, the established model has been verified availably after optimization based on molecular mechanics and molecular dynamics.

Abstract: Nano-crystalline diamond (NCD) films with good adhesion were deposited on flexible copper substrate with Ni interlayer by Microwave Plasma Chemical Vapor Deposition (MPCVD). In this paper, two-stage method was used to improve the adhesion between the copper substrates and the diamond films. The effect of deposition time of the first stage on the morphology, crystal structure, non-diamond phase and adhesive properties of diamond films was investigated. The performance and structure of the diamond films were studied by Scanning Electron Microscope (SEM), Raman Spectroscopy (Raman) and X-Ray Diffraction (XRD). The results showed that the films were nano-crystalline diamond films positively. Impress method was used to examine the adhesion between diamond film and the substrate. When deposition time is 1.5h, the adhesion between diamond film and the copper substrate is better than the others. When it was 2.5h or longer, because the graphite layers existed as intermediate, the adherence between the diamond films and copper substrates was very poor. Therefore, the diamond films were easily peeled off from the substrates. Otherwise, the second stage called annealing process after the deposition played an important role to the adhesion. The films would be easily peeled off by curling without the annealing process.

Abstract: The aim of this study is to explore alloy 718 that treated at an optimal HIP process, and then imposed various solid-solution temperatures and aging treatment. The experimental results indicated that Laves and δ precipitations obviously appeared within the grain boundary, under HIP treatment and lower solid-solution temperatures (940°C), which would result in poor mechanical properties. However, Laves and δ phase can be completely dissolved at 1020°C 1 hour solid-solution treatment. The tensile strength was increased to 1331.5 MPa, and elongation reached up to 6.1% under a 1020°C solid-solution and aging treatment. Increasing the solid-solution temperature to 1060°C would cause parts of the NbC to dissolve, thus a large number of the thin sheet-shaped NbC would appear in the solid-solution and aging specimen. The yield stress is slight increase, but a lot of NbC precipitations will result in the decreasing tensile strength (1298.8 MPa) and elongation (5.4%). As a result, the optimal solid-solution treatment parameter of alloy 718 is 1020°C for 1-hour.

Abstract: A facile method for the synthesis of N-{2-[4-(2-pyrimidinyl)-1-piperazinyl]ethyl} adamantane-1-carboxamide(Adatanserin) was developed by using 2-chloropyrimidine and adamantanecarbonyl chloride as the starting material via amidation and N-alkylation, using convergent route to reduce workups and steps in a good yield. The structures of compounds were confirmed by IR spectral, 1HNMR and elemental analyses.

Abstract: A series of LiY(WO ₄)(MoO ₄):Eu ³⁺ red phosphors have been synthesized by solid state reactions at high temperatures. The effect of Eu ³⁺ doping concentration, calcination temperature, reaction time and ratio of W/Mo on the optical properties of the red phosphors are studied and optimized. The phase impurity and spectroscopic properties are characterized by X-Ray Diffraction (XRD) and Photo-Luminescence (PL) spectra respectively. It is found that all the samples can be excited efficiently both by near ultraviolet light (395 nm) and blue light (464.5 nm), which match well with the emission of GaN based LED chips. The luminescent intensity maximizes for the sample of Eu ³⁺ 5 mol % in doping concentration (replacing Y) and W:Mo=1:1 in mole with calcinated of 750°C. To improve the dispersion and change the morphology of the phosphor powders, the sample is post-processed through ultrasonic dispersing method and the luminescent intensity of the post-treated sample increases by nearly 20%.

Abstract: SPEEK can be dispersed in water as well as WPU, so the coating for SPEEK/WPU can be obtained in the water, and its films were investigated on the structures and properties by SEM, TGA, Shore Durometer and so forth, the results show that SPEEK as a micro-phase can disperse in WPU phase, and there is a good thermal stability when the temperature is below 290°C, and there is good improvement on the hardness of the films of coating that is about 60HA-65HA. The pH of the coating for SPEEK/WPU is about 7.0-8.0. The ratio of water absorption for films of the coating for SPEEK/WPU is about 10% and is below that of WPU, swelling of the films for solvents is also below that of WPU.