Advanced Materials Research Vols. 393-395

Abstract: In global open economy, transaction price estimation is an important issue in finance under stock price fluctuation. However, the transaction price is depend on the investors’ expect price which is difficult to be captured in used and implemented models for transaction price estimation. Therefore, this paper proposes the Transaction Price Estimation Model (TPEM) and designs a novel Real-time Transaction Price Estimation System (RTPES) which adopts the TPEM based on the efficient market hypothesis to estimate the investors’ expect price. In experiments, the simulation results show that the average accuracy of TPEM is 99.37%. This approach is feasible for stock investment decision-making.

Abstract: The effect of quenching temperature, tempering temperature and tempering time on hardness of 45CrMnSi steel was studied by orthogonal test. It was found that the order of significant factors for the hardness was quenching temperature > tempering temperature > tempering time. Based on the results of the range analysis, the optimum process parameters for the maximum hardness were that the quenching temperature was 900°C, the tempering temperature was 150°C, and the tempering time was 180 min. Under the optimum process conditions, the hardness reached to HRC52 with impact toughness of 15 J/cm2. The hardness and toughness met the need of the comprehensive mechanical property and proper toughness of 45CrMnSi.

Abstract: A novel photochromic hybrid diarylethene bearing an isoxazole moiety was synthesized and its photochromic and fluorescent properties were also investigated. This compound exhibited good photochromism and functioned as a fluorescence switch upon alternating irradiation with UV and visible light both in solution and in PMMA film. Using this diarylethene 1c as optical storage was performed successfully.

Abstract: The effect of combined addition of Fe and Mn on carbon inoculation of Mg-3% Al alloy was investigated in the present study. The results show that a posioning effect could be found in the samples treated by the combination of carbon inoculation and combined addition of Fe and Mn regardless of the operating sequence of carbon inoculation and combined addition of Fe and Mn. The posioning effect was proposed to be due to the formation of Al-C-O-Mn-Fe-rich intermetallic compounds. These Al-C-O-Mn-Fe-rich intermetallic compounds, actually being Al-C-Mn-Fe phases, should not act as the potent nucleating substrates for -Mg grains, resulting in the grain-coarsening.

Abstract: The regression principle of support vector machines (SVM) based on the statistic learning theory is introduced and mathematical model combined with grid search and Leave-one-out cross validation (LOOCV) which is used to predict the porosity of porous NiTi alloy from processing parameters is established by support vector regression technology. In this model, temperature, particle size and green density are as input parameters and porosity of reacted products is as output paramater. The results show that the relative maximum predicting error is 0.1% under the condition of using a small quantity of samples to build the mathematical model, and the predicting precision of SVR model is obviously better than that of BP neural network model. It is suggested that SVR is an effective and powerful tool for predicting porosity of porous NiTi alloy.

Abstract: Heparin (Hep)-immobilized poly(ether urethanes) (PU) was prepared by a unique preparation procedure. Firstly, the poly(ether urethanes)(PU) containing diester groups in the side chains were synthesized. Then, PU was dispersed in aqueous solutions and immobilized with heparin after the hydrolysis of diester groups and carboxylation. The Fourier transform infrared spectroscopy (FTIR) and water contact angle (WCA) were used to characterize the heparin-bonded PU. The amount of heparin grafted on the PU was determined to be 0.57wt.% by the toluidine blue method. The heparin-immobilized PU could release just 12% of the immobilized heparin in the early 10 hours of the 70 hours immobilized heparin stability test.

Abstract: Monodisperse hollow silica nanospheres were prepared using functionalized polystyrene (PS) as a template and characterized by transmission electron microscopy (TEM), nitrogen adsorption and thermo gravimetry (TG) techniques. The effect of ammonia amount on hollow silica spheres was explored. It is found that the ammonia amount is important to the fabrication of hollow silica nanospheres. The roughness and thickness of the silica shell increased with the increase of ammonia amount. When ammonia amount reached 20 ml, the product hadn’t been hollow structural. The TGA curves and the BET results of the samples supplied a proof for the formation mechanism of the hollow silica spheres.

Abstract: Europium-doped nanocrystalline ZrO₂: Eu³⁺ powders with different doped concentrations were prepared by emulsion processing method, with different doped concentration and calcination temperature on the material grain size, structure, size and luminescent properties. The results show that: Eu³⁺ has a stabilizing effect on tetragonal phase of ZrO₂. Emission spectra indicates that the main emission peak in the 593m and 608m, “Blue Shift “will occur in 5D₀ → 7F₂ transition of the emission spectra of sample with the sintering temperature at 1000°C. Samples with the sintering temperature soaring, spectral emission intensity also increases.

Abstract: TiB₂/Al composites were prepared by the direct melt reaction using Al-3B master alloy and Ti powder as the reactive materials. The phase composition and the microstructure of the as-prepared composites were investigated by XRD, SEM, TEM etc.. It is showed that the reinforcement was only TiB₂, moreover, the volume fraction of the reinforcements increased with the increasing of the reactants. The TEM images showed that TiB₂ particle was in the shape of hexagonal, circle and rectangle, and its size was 0.5-2μm.

Abstract: ITO (Indium Tin Oxides) nano-powder was prepared by the method of ammonia complexation. The chemical composition, morphology and crystal structure were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Base on the nucleation and growth mechanism of the powder, the temperature of heat treatment impacting on size and morphology was discussed briefly. The results showed that the nano-ITO powder of particle size 20nm-40nm with well-pleasing particle shape and dispersion can be prepared at 800°C.