Advanced Materials Research Vols. 550-553

Abstract: Melamine and boron trioxide (B₂O₃) were directly pyrolyzed in semi-closed system to prepare Boron doped g-C₃N₄. The analytic results of XRD, XPS and FTIR proved that g-C₃N₄ is doped by boron successfully. The thermal decomposition of B doped g-C₃N₄ has been studied using TGA-DTG technique. The iterative procedure method was employed to calculate the activation energy E_α, and the most reasonable kinetic function of the decomposition of B doped g-C₃N₄ was confirmed by the integral method with 36 types of kinetic function .

Abstract: A quantitative structure property relationship (QSPR) study was performed in this work to develop models for predicting reaction rate constants for reductive debromination of polybrominated diphenyl ethers (PBDEs) by zero-valent iron (ZVI). Both multiple linear regression (MLR) and artificial neural network (ANN) methods were employed for QSPR studies based on the experimental kinetic data of the fourteen PBDE congeners. Both the developed MLR and ANN models could give satisfactory prediction abilities, and the performance of the ANN model seems slightly better than that of the MLR model. In addition, energy of lowest unoccupied molecular orbital (ELUMO) and total energy (TE) were found to be the two relatively important variables in the ANN model via the assessment using both the Garson’s algorithm and connection weight approach.

Abstract: The thermodynamic analysis of stability conditions was carried out for disperse heterophase systems obtained by a method of NSP put in metal melts for high-temperature strength of the nickel alloys. For a thermodynamic criterion (К) of stability was selected the specific variation of a free energy of the process of a disperse system degradation (referred to unit of a surface phases contact change). The analysis was carried out in view of formation of thick and thin elastic wetting films and takes in account a disjoining pressure. Obtained new thermodynamically rigorous criterions can be used, if the isotherm of a disjoining pressure is measured. The derived criterions are simplified in the Young approximation. In this case the criterion are expressed through measurable interfacial performances - interfacial tension and wetting angles. The application of a stability condition gives a simple outcome: aggregation of NSP does not happen at a wetting angles ≤ 75⁰. On a basis of own experimental data the evaluations are carried out for possibility of using of some compounds as exogenous modifiers of a nickel alloys. The example of dispersion hardening of high-temperature strength nickel alloy is reduced.

Abstract: With poly aluminum ferric silicate (II) and magnesium (PSAFMS) coagulation treatment of four kinds of reactive dyes, through the determination of its absorbance with coagulation time changes, studied the coagulation reaction kinetics problems, as PSAFMS coagulant development would lay the theoretical foundation of application. Under coagulation condition that the water temperature was 8°C, pH=11, PSAFMS coagulant dosage was 10 ml/L, in 3 minutes the decolorization rate of reactive red RSB was 94.6%, reactive blue 3GF was 93.3%, reactive navy blue S-G was 80.8% and reactive yellow M-3RE was 75%. Different reactive dye decolorization rate is differences. It is related to dye molecular structure and particle size of the radius. From ln(0/t)-t, (1/0-1/t)-t relation curve of the linear correlation coefficient, the first-order reaction of the linear correlation coefficient than the secondary correlation coefficient was better, and more than 0.9668, so PSAFMS coagulant with reactive dye decolorization reaction is the first-order. The rate equations for the ln(0/t) = kt, just different reactive dye has different reaction rate constant. .

Abstract: This paper designs a novel dew point indirect evaporative cooler. An experimental system of dew point indirect evaporative cooler is built up, The experimental results indicate that temperature of the primary air and the dew point efficiency have a positive relationship with the inlet temperature and relative humidity. Generally, in order to meet the blowing air requirements, maintain the high cooling efficiency and low temperature of the outlet air, the velocity of primary air should be 3m / s and the rate of primary and secondary air should be 1.5:1. When the flux of water is 3L/min the dew point efficiency is highest. In addition, the cooling effect was less affected by the temperature of the water.

Abstract: In order to develop a new technology for separating the bloedite by the method of gas hydrate formation, the phase equilibrium of the H2O-Na2SO4-MgSO4-C3H8 system and its subsystems was studied at 0°C and pressure.The equilibrium pressure and the composition of solid and liquid above system were investigated.It was found that equilibrium pressure of gas hydrate formation was increasing with the increase of the Na2SO4( or MgSO4) concentration. The addition of anionic surfactant SDS helped to lower the equilibrium pressure of gas hydrate formation. The mother liquor amount entrained in the gas hydrate after liquid separation by sinking was very high when surfactants was not added. But the equilibrium pressure of gas hydrate formation and the mother liquor amount entrained in gas hydrate were decreased when surfactant was added to the system.

Abstract: The fully optimized and vibrational analysis calculation of some silane compounds containing Si-Ph bonds were carried out at the B3LYP/6-31G* level, to obtain the thermodynamic parameters of the molecules in standard state 298.15K, 1.013 × 105 Pa. Based on the output file of the Gaussian 03 program, using the statistical thermodynamic program to calculate the molar constant pressure heat capacity (Cp, m)of phenyl substituted silane derivatives from 200K to 1800K, the correlation between the Cp, m and temperature (T, T-1 and T-2) was fitted with the least square method, and what was found was that the Cp, m of series of phenyl substituted silane derivatives had a very good correlation with T, T-1 and T-2.

Abstract: The kinetic process of the reduction reaction between phosphorous acid and adamsite has been studied to determine the reaction rate equation and to deduce the reaction mechanism, providing the theoretical basis for destroying adamsite by phosphorous acid.

Abstract: Many researchers have shown a great deal of interest in the effects that magnetic fields have when applied in chemical reactions, crystallization, magnetic separation of materials, magnetic levitation, materials processing, and wastewater treatment. However, surprisingly little research has been done on the effects of magnetic fields on the vapor-liquid equilibrium and the thermodynamic model for vapor-liquid phase equilibrium. The influence of magnetic fields on vapor-liquid equilibrium of binary heterogeneous azeotrope was investigated with ethanol-water in this paper. It was found that the vapor-liquid equilibrium of an ethanol-water system is influenced by the external magnetic field, but that the azeotropic point of the ethanol-water system is not changed by the magnetic field when the magnetic intensity reaches 0.8 T. Rather, the exerted magnetic field reduces the equilibrium temperature and shortens the distance between T-x curve and T-y curve in T-x-y diagram of the vapor-liquid equilibrium of the ethanol-water system. A thermodynamic model for vapor-liquid phase equilibrium in the exerted magnetic field was derived theoretically, based on the fundamental thermodynamic theory. The results show that the logarithm value of the ratio of the composition of the certain component in a magnetic field to that without the magnetic field is proportional to the magnetic susceptibility of the solution, and to the square of magnetic field intensity. This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text.

Abstract: This work presents a first-principles molecular dynamics study of hydrogen storage in Li doped single-wall carbon nanotubes (SWCNTs). The decomposition and adsorption between Li atom and H2 molecular are studied by bonds analysis and energy evolvement of interaction process. The modify effects of Li doped SWCNTs are studied by band structure and of states density analysis, as well as the structure transformation of SWCNTs. The enhanced hydrogen storage in Li doped SWCNTs at room temperature and common pressure is studied by first principles molecular dynamics simulation. The relationship between dope position of Li atoms and hydrogen storage also studied, and finally confirm the best dope position and provide a reference for the further research of alkali metals doped CNT.