Advanced Materials Research Vols. 233-235

Abstract: Variations of decomposition rate and decomposition layer thickness of six spherical limestone particles with different sizes are calculated and compared with each other by the experiments and model of static decomposition of limestone under constant temperature. The results indicate that: the decomposition process of limestone can be explained by unreacted core model (UCM) when it is heated sharply; the decomposition rate of large particle is greater than that of small one; the smaller particle size, the larger decomposition layer thickness in unit time.

Abstract: The top quality magnesity-chrome adding Indian concentrate chrome ore as investigated at this present. The samples adding 5%、10%、15%、20% Indian concentrate chrome ore respectively are prepared. The results shown that the thermal shock resistance of the brick is improved by adding right quantity of Chromium Concentrate and the brick which adding Chromium Concentrate have a better performance.

Abstract: The reaction kinetics for synthesis of vanillyl nonanoate (VN) by lipase-catalyzed transesterification of vanillyl alcohol and methyl nonanoate in acetone was investigated in this study. The reaction catalyzed by lipase was carried out as follows: A reaction mixture containing given concentration of substrates (1ml) and lipase Novozyme 435 (20mg) in acetone (1ml) was shaken at 30°C for 10min. The initial velocity of the reaction was calculated according to the concentration of VN detected by high performance liquid chromatography (HPLC), and the kinetic equation was obtained by analysis of the double reciprocal plot of initial velocity versus substrate concentration. The data calculated by the kinetic equation were basically in agreement with the experimental data with a correlation coefficient at 0.997. The inhibitory action of methanol (by-product) in the reaction was also investigated and the results indicated that the concentration of methanol influences both slope and intercept of y-axis of the double reciprocal curve, and the lines intersect on the X-axis. These results revealed that this transesterification follows the Ping-Pong reaction mechanism.

Abstract: Quick, accurate and reliable detection of mash gas plays an important role in the coal industry. This paper presents a novel method to get the infrared absorption peak wavelength by light splitting using plane blazed grating, instead of using filter conventionally. The principle and setup of producing 3.433μm and 4.65μm wavelength lights for detecting CH₄ and CO concentration are described in details. The work provides a simple, but efficient option to the infrared absorption gas detection technology.

Abstract: The temperature sensitive behavior and the phase behavior of linear poly(N-isopropylacrylamide) (PNIPA) in water-additive systems were investigated via turbidity measurements.. Three kinds of additives, including acrylic acid (AA), acryl amide (AM) and N-vinyl-2-pyrrolidone (VP), were selected. AM and VP systems only exhibited a different lower critical solution temperatures (LCST) behavior with different additive concentrations, and in low concentration of AM or VP, LCST decreases with additive concentration increasing, but in higher concentration, LCST decreases with additive concentration increasing. However, it was first detected the coexistence of a LCST with an upper critical solution temperature (UCST) in AA system. The systems studied here are alternative functional molecular material for the shading agent in some special conditions.

Abstract: Hybrid gels with boron-chelating groups were prepared using bis(trimethoxysilylpropyl)amine (TSPA) and the precursors synthesized from (3-glycidoxypropyl)trimethoxysilane (GPTMS) and N-methylglucamine (MG). Boron adsorption by the hybrid gels and a commercial boron-selective resin D564 were compared. The experimental results demonstrated that sol compositions have a great effect on the boron adsorption by the hybrid gels. Changing the sol compositions is a convenient way to adjust the adsorption capacity of the hybrid gels. The highest boron adsorption amount of the hybrid gels was found to be 1.54 mmol g^-1, higher than that of the commercial resin D564 (1.39 mmol g^-1). The hybrid gels reported in this study are easy to prepare, having a higher adsorption capacity and a good mechanical strength.

Abstract: As a unique mode of soil erosion, loess cavities often act as the critical factor to the stability of the highway slopes of unsaturated loess. In this paper, the unsaturated loess slope stabilities are comparatively studied in different cases through the developed program of the strength reduction FEM, such as loess cavities in different position, single- & twin cavities, occurrence and loss of matric suction etc. The work done in this paper revealed the mechanism how the tunneling and the matric suction have effect on the stability of unsaturated loess slope to some extent. The results not only indicate that the loess cavities favor to maintain the stability of slope with the cavities located near the slope's crest, while the loess cavities reduce the stability of slope with the cavities located near the slope's toe, but also disclose that the safety factor of the unsaturated loess slope increases and the potential sliding surface move downward with considering the matric suction and vice versa. In addition, the twin cavities near the slope's toe have the obvious negative effects on slope's stability.

Abstract: Stable monolayers of Tb (III) -ocat-4-n-nonyloxyphthalocyanine (TbPc₂) and TbPc₂ blended with amphibious arachidic acid (AA) on air-water interface have been obtained and their solid multilayers have been successfully deposited by Langmuir-Blodgett (LB) technique. The characteristics of their structure and fluorescence are disclosed. The multilayer has a periodic layered structure with a layer spacing of 2.2 nm. Fluorescence lifetime results suggest that the excitons exist by photo-excitation in the film of TbPc₂.

Abstract: Magnesium carbonate precipitation by the reaction of MgCl₂ with Na₂CO₃, using sodium tartrate as an additive was studied. The effects of sodium tartrate concentration, reaction temperature, and stirring speed on the precipitation were investigated comprehensively. Scanning electron microscopy (SEM) and X-ray powder diffraction methods were used to characterize the carbonate precipitate products. Sodium tartrate concentration, reaction temperature, and stirring speed have significant effects on the morphology of the carbonate products. Sodium tartrate has an inhibitive effect on the precipitation. The product weight decreases with the increase in the amount of sodium tartrate added, and with the increase in reaction temperature, but is almost irrelevant to the stirring speed. The products obtained at 25 and 50°C were all identified as nesquehonite. The experimental results show that the use of an additive would be an effective method to adjust the morphology of magnesium carbonate.

Abstract: A hybrid gel adsorbent bearing boron-selective functional groups was prepared by the reaction of bis(trimethoxysilylpropyl)amine (TSPA) and a gel precursor in water. The gel precursor was synthesized from (3-glycidoxypropyl)trimethoxysilane (GPTMS) and N-methylglucamine (MG). The boron adsorption behavior of the gel and a commercial boron-selective resin D564 was investigated. The gel adsorbent has a suitable mechanical strength and an adsorption capacity of 2.00 mmol g^-1, which is higher than that of the resin D564 (1.64 mmol g­^-1). Boron can be desorbed from both the gel and the resin D564 with a 0.25 mol L^-1 HCl solution. The good reusability of both the gel and the resin D564 was confirmed by fourteen consecutive adsorption-desorption-regeneration cycles.