Applied Mechanics and Materials Vol. 389

Abstract: Biodiesel has attracted considerable interest in recent years as an alternative, biodegradable and nonpolluting transportation fuel. Conventional alkaline process for biodiesel production are energy consuming and generate undesirable by-products such as soaps, that make difficult the separation and purification of biodiesel. Ionic liquids as environmentally benign chemical solvent, had been used in diverse chemical reactions. Especially, they could be applied in biodiesel production. Preparation of biodiesel catalyzed by ionic liquids have many merits, such as no corrosion to equipment, no pollution to environment, and reusability. Ionic liquids can improve the catalytic activity and they have wide utilization prospect in biodiesel preparation. In this paper, the advances in the Brønsted ionic liquids catalysts and their application in biodiesel production through transesterification of oils and fats were reviewed. In addition, the prospect for the application of the ionic liquids to catalyze biodiesel production was also stated. Since the cost of ionic liquid may be an issue, there are some challenges to be faced, such as the production of ionic liquids with low cost, easy recovery and with the possibility of reutilization of the catalyst for several cycles.

Abstract: The mesoporous TiO₂ particles was conveniently prepared in a room temperature ionic liquid (RTILs) of 1, 3-di-(3-propionyloxy) imdazolium tetrafluoroborate [DiprCOOBF₄ system. The obtained materials were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and N₂ adsorptiondesorption analysis. XRD patterns revealed that only rutile phase is formed in the RTILs. The TEM micrographs as well as N₂ adsorptiondesorption measurements show that the prepared products exhibited wormlike pore structures. The FTIR (Fourier Transform Infrared Spectra) demonstrate the carboxylate groups attach via bidentate or bridging coordination to the TiO₂ surface.

Abstract: The orthogonal experiments were taken to determine the best metamorphic process parameters of ZL102 by the metamorphic temperature, holding time, and the added amount of Sr and RE. The results indicated that the added amount of Sr and RE were 0.035 wt% and 0.03 wt%, the metamorphic temperature of 740 ° C, holding time of 60 min. The microstructure of the alloy of eutectic silicon became completely the α-Al was small short rod, the tensile strength was 230.5MPa, an elongation of 2.77%.

Abstract: Based on the recursive stiffness matrix method, the effective surface permittitivity model of multilayered Surface Acoustic Wave structure was established. By this model the phase velocity dispersive of ZnO/Si layered structure was calculated. The calculation results is in agreement with the experimental results ,which verifies effectiveness and accuracy of the model. Furthermore, the model was also carried out for the determination of the phase velocity and electromechanical coupling coefficients of ZnO/Diamond/Si structure. The best combination of high velocity and high coupling coefficient of the structure was obtained, which provided a good reference for the design of the high performance and high capability Surface Acoustic Wave device.

Abstract: An experiment was conducted to explore the integrated evaluation on soil nutrients in spring maize field subjected to limited irrigation (LI) in oasis region. The soil organic matter (SOM), soil total and available nitrogen (STN and SAN) and phosphorus (STP and SAP), and soil available potassium (SAK) in 0~40 cm increment at harvest of maize subjected to LI were selected as the evaluation factors to calculate the weighing coefficient of each soil nutrient and the IEI for soil nutrients using the membership function in fuzzy mathematics. At maize harvest, differences were not significant (p>0.05) in SOM, STN, STP, SAP, and SAK within 0~40 cm increment among treatments and CK, but significant difference (p<0.05) was found in SAN, with the maximum SAN maintained in MI₅, which was respectively 187.3%, 96.8%, and 41.2% higher over MI₂ valued the minimum, MI₁, and CK. The IEI was improved by 12.4% to 22.3% in all the other treatments and CK compared to the minimum marked in MI₄, with the maximum valued in MI₃ treatments. Therefore, after one year experiment, the optimized irrigation management was maintained in MI₃ treatment due to its maximum IEI in all the LI regimes.

Abstract: An experiment was carried out to optimize limited irrigation (LI) schedules for spring maize in a desert oasis region. The grain yield, water use efficiency (WUE), irrigation water use efficiency (IWUE), and integrated evaluation index for soil nutrients (IEISN) in 0~40 cm soil depth of maize field subject to LI were selected as the synthetical factors in evaluating and optimizing the LI schedules. The unifactor matrix and weighing coefficient matrixes of evaluating factors were formed for fuzzy judgement and the synthetical evaluation index (SEI) determination. Compared to the minimum in MI₄, the SEI for spring maize was respectively improved by 46.5%, 20.9%, 38.9%, 27.8%, and 23.8% in MI₁, MI₂, MI₃, MI₅, and CK. Therefore, the MI₁ irrigation regime was recommended as the optimized LI schedule for spring maize in the desert oasis region due to its maximum SEI caused by the least water application, maximum grain yield, WUE, and IWUE, and 95.2% of the maximum IEISN.

Abstract: The molten carbonate fuel cell (MCFC) is an important research field of the new energy generation equipment, and is a difficulty in the research field of high-temperature fuel cells at present. To aim at the MCFC modeling problem, the MCFC electrochemical mechanism process was analyzed firstly, then the MCFC modeling applied neural computing is advanced. Thirdly, the structure, algorithm and simulation of MCFC modeling based on feedback neural networks were presented in detail. Finally, the computer simulation and conducted experiment verified that this model was fast and accurate, and can be as a suitable operational model of MCFC real-time control.

Abstract: The rural energy is one of important factor in energy system, which connects closely with new rural construction. The analysis on Beijing rural energy problems will benefit to solve the national rural energy problems on referential meaning. In this paper, the situation of Beijing rural energy problems in 2007 is analyzed, and the problems which exist in rural energy development are found. Meanwhile, it introduces the policy of Beijing rural energy construction and its target, and suggests that rapid developing the rural renewable energy in order to adjust the structure of Beijing rural energy consumption.

Abstract: The carbon emission caused by land use change is a human carbon source only second to fossil fuel combustion, the urbanization process in China is extremely intensified, which carbon emissions effect caused by land use change becomes a key factor to influence China's target of carbon emission reduction. Taken Shenzhen city as a typical case, this study utilizes unit root and co-integration test method to research existence of carbon emissions EKC (Environmental Kuznets Curve) in Shenzhen on the basis of the carbon emissions EKC theory and land-use carbon emissions data of 1979-2010 years, in combination with the existing research foundation. The result proves that, the carbon emission EKC per capita exists in Shenzhen, and the inflection point time of carbon emissions per capita is also calculated for Shenzhen city, which provides new research ideas and scientific guidance for urban carbon emission reduction in China.

Abstract: In order to evaluate the economy performance of new energy vehicles, the life-cycle cost theory is applied. A formula of quantitative analysis in combination is adopted to have in-depth study on the life-cycle cost of new energy vehicles. Analysis and argumentation are also conducted in comparison pure-electric vehicles, hybrid electric vehicles and traditional oil-fueled vehicles under the condition of present oil price, the analysis result shows that if despite the battery cost, PEV costs the fewest because of the lowest operation costs and energy costs, the cost of HEV is at a middle level. Therefore, customers and manufacturers may become more interested in PEV than in other solutions. Furthermore, a decision tool by setting up a cost model based on linear programming theory is developed, economic influence factors for the application of new energy vehicles are further discussed through sensitivity analysis.