Applied Mechanics and Materials Vols. 291-294

Abstract: The widely used single assessment index such as energy consumption and main pollutants total emissions index can't comprehensively evaluation energy conservation and emission reduction. In this paper, a scientific comprehensive evaluation method of energy consumption based on the product life-cycle was proposed. This method fully consider industry characteristics at the same time, comprehensively use stratified fuzzy evaluation method. And the multi-objective colligation evaluation model and scientific evaluation system for energy saving and emission reduction oriented to industry characteristics was constructed. Finally, the empirical research was carried out take the heat treatment industry in Ningbo city as an example, and the result shows that this evaluation system is scientific and reasonable.

Abstract: The microstructure and corrosion behavior of commercial AZ91/AZ91-0.4%Nd alloys were investigated by OM, immersion test and weight-loss method. It was found that the number of Nd element in the AZ91 magnesium alloy has effect on the grain refining efficiency, the coarse β-Mg₁₇Al₁₂ phase distributed along the grain boundaries transformed into granular, and the granular or acicular Al₃Nd phase precipitated in matrix. The addition of Nd element significantly reduces the corrosion rate of AZ91-0.4%Nd magnesium alloy, as a result the corrosion resistance of alloy was improved obviously.

Abstract: CIGS thin films were deposited on soda lime glass by one-step magnetron sputtering using a single quaternary-CIGS target in stoichiometric proportions. The influences of substrate temperature on the structural, optical, and electrical properties of Cu(In,Ga)Se₂ (CIGS) thin films were investigated. The phase structure of CIGS thin films was characterized by X-ray diffraction (XRD). The morphology and thickness of CIGS thin films were observed by Scanning Electron Microscope (SEM). The absorption coefficient of CIGS thin films was measured by Ultraviolet-visible Spectrophotometer. Four-point probe method was used to test the resistivity of CIGS thin films. Based on the results of characterization, the increase in crystallite size of CIGS was found to be significantly noticeable with increasing substrate temperature. UV-vis measurement analysis suggested that CIGS thin films deposited at different substrate temperatures had high absorption coefficient (~10⁴ cm^-1) and optical band gap (1.07-1.23 eV). The substrate temperature dependence of the resistivity of the films indicated that the resistivity of the films fall to about 0.5 Ω۰cm as the substrate glass was heated up to 300 °C.

Abstract: A facile topochemical route has been developed to synthesize porous LiMn₂O₄ spheres by using molten LiOH and porous Mn2O3 spheres as a precursor. The formation of porous LiMn₂O₄ spheres was inherited from porous Mn₂O₃ spheres which were obtained from the thermal decomposition of the MnCO₃ precursors and the presence of pores was confirmed by transmission electron microscope (TEM) and field emission scanning electron microscope (FESEM). When applied as cathode materials for rechargeable lithium-ion batteries, it shows good capacity retention after cycling. Taking the excellent electrochemical performance and facile synthesis into consideration, the presented porous LiMn₂O₄ spheres could be a competitive candidate cathode material for high-performance lithium-ion batteries.

Abstract: Liquid co-precipitation method was applied to produce LiFePO4 cathode materials in which Ferrous carbonate was used as raw material. The morphology and electrochemical property of LiFePO4 were characterized by XRD, scanning electron microscopy (SEM) and charge/discharge test respectively. The results show when the precursor was synthesized at 80°C and then heat treated at 700°C for 5h, the particle size of LiFePO4 was 0.1-1μm and the obtained LiFePO4 shows impressive discharge specific capacity of 155mAh•g^-1 at 1C rate.

Abstract: The interaction between amorphous silicon dioxide (SiO2) with surface (100) and mixture of glycerol and 1,6-hexanediol was simulated with periodic boundary conditions using the method of molecular dynamics. The properties of silicon dioxide depend on polarity of the groups of the surface. The simulation was respectively calculated that silicon dioxide surface with all silanol groups (Si-OH bonds) or all Si-O bonds interacts with hydroxyl of mixture of glycerol and 1,6-hexanediol in the paper. The results show that the peak of radial distribution function of hydroxyl of mixture on silicon dioxide surface with Si-O bonds is higher than that of the hydroxyl of the mixture on the surface with Si-OH bonds. And self-diffusion coefficient of hydroxyl of the mixture on the surface with the Si-O bonds was smaller than that of hydroxyl of the mixture on the surface with the Si-OH bonds. Interaction energy of silicon dioxide surface with Si-O bonds and the mixture is stronger than that of silicon dioxide surface with Si-O bonds and the mixture at different temperature respectively.

Abstract: The improved dye-sensitized solar cells were fabricated using TiO₂-carbon nanotube nanocomposite photoanodes. An improvement of 91 % for power conversion efficiency is achieved through the incorporation of carbon nanotubes into TiO₂ mesoscopic film photoanodes. The further investigation indicates that enhancement of power conversion efficiency depends on the carbon nanotube content in nanocomposite photoanodes. With the carbon nanotube content increasing from 1 to 3 wt. %, the power conversion efficiency of solar cells significantly improves from 3.02 to 5.78 %. When the carbon nanotube content is up to 5 wt. %, however, its value is down to 4.24 %.

Abstract: The CO₂ reforming of CH₄ over carbonaceous catalyst was performed using a Plug Flow Reactor in the temperature range 800~1100°C, the ratio of CH₄/CO₂=1 and residence time 2~30s under normal pressure. The results showed the carbonaceous catalyst was an effective catalyst for carbon dioxide reforming of methane. With increasing the reaction temperature and residence time both the CH₄ conversion and CO₂ conversion increased. However, the CO₂ conversion was significantly higher compared with the CH₄ conversion under the same reaction conditions, which indicated that the gasification reaction of the carbonaceous catalyst and carbon dioxide occurred during the reforming process. Under a reaction temperature of 1050°C and residence time over 30s, the conversion of CH₄ and CO₂ were 92.7% and 95.4% respectively. The oxygen groups, surface area and pore volume decreased as well as the micro-porous structure of the catalyst surface was significantly reduced for the carbonaceous catalyst after reaction.

Abstract: Michael-type addition of stabilized phosphorus ylides to nitroolefins was accomplished under microwave irradiation for the first time. Its subsequent reaction with formaldehyde provides γ-nitro-β-aryl-α-methylene arone. The solvents, microwave time and power were screened, the best yield was got(up to 62% ).

Abstract: Based on the principle of thermal balance and materials balance in lime furnace, a calculation model used for on-line testing the resolution ratio of baked limestone in lime furnace is conducted by using of parameters that can be measured in spot. For a lime furnace in operating, the resolution ratio of baked limestone can be predicted on time by this model when mass input of limestone, coke ratio, air flux, concentration of carbon dioxide in outlet, temperature of flue in outlet and temperature of output lime are measured in-line. The calculation model has been testified with actual parameters and proved to be operable.