Advanced Materials Research Vols. 430-432

Abstract: Based on the density functional pseudopotential method, the electronic structures and the optical properties for Ti doped ZnS are investigated in detail. The calculation results indicate that the doping of Ti widens the band gap of ZnS and the Fermi level shifts upward into the conduction band. The impurity elements form new highly localized impurity energy level at the bottom of the conduction band near the Fermi level.,.Meanwhile, blue shifts are revealed in both the imaginary part of dielectric function and the absorption spectra corresponding to the change of band gaps.

Abstract: Research on cement concrete under corrosion fatigue is mainly focused on experimental research which is difficult to reveal the physical mechanism of deformation and failure. Models for sulfate attack have been based on the different scientific fields of engineering, mechanics, physics, and mathematics. For this problem, the numerical solution of the cement concrete under the fatigue corrosion is established with establishing diffusion reaction equation basing on Fick's second law under the coupled action of corrosion fatigue and obtaining the stress-strain response

Abstract: According to the two-dimensional thermal theory, the temperature distribution in a simply supported laminated beam is studied. Firstly, the temperature distribution in a single-layer simply supported beam is analytically derived. Then, based on the continuity condition of the temperature and heat flux between the connected layers, the temperature and heat flux relations between the lowest layer and the top layer of the beam are recurrently obtained. Finally, the unknown coefficients are determined by the upper and lower surface conditions of the laminated beam. The temperature in the beam is given by substituting the unknown coefficients back to the recurrent formulae.

Abstract: The purpose of this study is to explore the alternative ways of performing teachers training programs from the perspectives of students, teachers, and schools to propose the methods of reformation of defense education courses in Taiwan. The research results show that the effects of national defense education are uncertain for three reasons. First, the correspondences of high schools with "core subjects of national defense education for general high schools" released by the Ministry of Education in 2008 is questionable. Second, the course time of national defense education in high schools has been changed to one hour per week, which is relatively short course time. Third, the outcome of the policy of elective courses of general education and the development of teachers training program for defense education is under observation.

Abstract: This paper is a re evaluation of CAES Compressed Air Energy Source. CAES is not new, experimental air car compressed air propulsion vehicles appeared in early 1900’s, and are currently exemplified by the India Tata Motors AirCar MiniCat based on the French MDI Motor Development International AirCar. (see Ulf Bossel, European Fuel Cell Forum) This study focuses on compressed air potential pressure specific energy density and specific power, ideal Global thermodynamic cycle efficiency, US EPA 23 cycle urban driving test schedule overall drive train ideal efficiency and vehicle ideal range. CAES analysis is unique because compression and expansion cycles are remotely linked solely by ambient atmosphere e.g., compression occurs in a stationary device while expansion takes place in a mobile vehicle. Therefore, ideal thermodynamic compression and/or expansion cycles can be treated independently and linked as isothermal entities e.g., both cycles are in fact separate ideal complete compression and/or complete expansion cycles without (TDC) top dead center piston clearance with isothermal ambient temperature compressed air storage. Further, CAES potential pressure energy density and power density are comparable to electro-chemical energy sources on a Ragone chart, e.g., CAES specific energy density and specific power based solely on stored pressure energy potential are similar to the Pb-Acid battery. However, modern forms of multi stage expansion air motors with heat exchangers between stages extract additional thermal energy directly from ambient air to increase vehicle range by a factor of ~ 6 with a four stage expansion motor. To minimize road-load energy consumption air powered vehicles are characterized by low curb (empty) vehicle mass and low speed urban traffic. Based on Tata AirCar design specifications, comparative theoretical driving range tests were simulated with the 23 cycle US EPA Urban (City) driving schedule and a modified low speed 23 cycle Urban schedule suitable for India. We concluded modern multi stage air car propulsion may find applications in temperate zones, particularly highly congested pedestrian trafficked city streets and retirement communities such as Sun City, AZ, India [5a-19a]

Abstract: Pyromellitic dianhydride(PMDA）- modified grain sorghum stalk was used as a novel low-cost adsorbent to remove cationic dye methylene blue(MB) from aqueous solution. Bath studies were carried out to investigate the effects of pH and retention time on the adsorption of MB. The adsorption process could obtain >98% removal percentage within 30 minutes as the MB concentration was at 200 and 300 mg/L. And for 400 mg/L MB, 99% was removed in 6 hrs. The kinetics study showed that the adsorption processes followed the pseudo-second-order kinetic model, which confirming that the sorption rate is controlled by chemical adsorption. Equilibrium isotherms were analyzed by the Langmuir and Freundlich models. Langmuir model can be fitted better than Freundlich with maximum monolayer adsorption capacity of 568.18 mg/g for MB.

Abstract: In this paper, based on the liquid forging part flange LY12, the influence of heat treatment on the organization and performance of the liquid forging part was studied through microstructure, mechanical properties and tensile fracture surface analysis methods, this article also has some guiding significance to the formulation of the best liquid forging process parameters. The results show that the sample after natural aging which mechanics performance is best, and grain is relatively small; the latter two that after artificial aging are relatively poor. With the extension of artificial aging time, the mechanical properties and the organization has a descending trend.

Abstract: A synthetic approach to synthesize 3,4-ethylenedioxyfuran from a common precursor Diglycolic acid is reported. Starting from ethylene diglycol, a six-step synthesis afforded EDOF in 10% overall yield. The procedure described herein offers several advantages, including high product yields, easy purification.

Abstract: Electric hot machining (EHM) can improve the cutting performance by heating resistance, consisting of metal resistance and constriction resistance, which softens the material in the deformation zone. In this paper, we present the 3D model for heating resistance and analyze its variance with experimental verification. The results show that 3D model for heating resistance can describe heating resistance well in EHM under this experiments condition.

Abstract: There are strong basal textures in AZ31 magnesium alloy sheet. Through rolling and post-annealing, we can significantly reduce the basal texture, and with the rising of deformation, the texture intensity falls. The peak intensity of basal texture reduced from 12 to 4 when the rolling deformation rises to 35%. The influence of post-annealing on grain refinement is very obvious. When the temperature of pre-annealing is 773K and rolling temperature is 623K, the grain size reduce to 201μm after 1% deformation. But we can reduce the grain size to 30μm after post-annealing. If the rolling deformation is 36.4%, the grain size reduces to 73μm. But after post-annealing, the grain size reduces to 12μm.