Papers by Author: Yu Shen

Abstract: ADDIE instructional design is a systematic approach for course development and instructional activities. It consists of analyzing the current state and needs of the learner, defining the end goal and expected outcomes of instruction, determining the instructional methods and approach, selecting the instructional means, synthesizing instructional plan, organizing and implementing instructional activities, and monitoring and evaluating instructional effectiveness. It gives a detailed illustration of the process of effectively designing and creating instructional activities for higher education classrooms and provides higher education lecturers with a well-defined structured procedures for instructional design.

Abstract: First-principles simulation was carried out to study the phase transformation of vanadium doped TiO₂ from anatase to rutile based on Ti5O10 cluster model. The Ti5O10 cluster models of anatase and rutile and corresponding V⁴⁺ isomorphous replaced cluster models were calculated to study the change of total energy, the ways of angular distortion, the change of frontier orbitals and the Ti⁴⁺ in the model preferentially substituted by V⁴⁺. The calculation results reflect that the V₂O₄ species, which has a rutile-like structure, can promote the phase transition from anatase to rutile. The single α electron in Ti4VO10 cluster model makes change to the frontier orbitals and the uneven contribution of electrons in valence shell may be the force driving the angular distortion in anatase lattice to rutile-like structure.

Abstract: Sweet potato (Ipomoea batatas) was a wildely planted root crop in most area of China and considered as a good feedstock for fuel ethanol production. Very high gravity ethanol fermentation technology exhibited promising industrial application for advantages including productivity improvement, polluted water output reduction and energy consumption saving. In this study very high gravity liquefied sweet potato mash containing 260 g/kg glucose (after fully saccharified) was used for fuel ethanol fermentation. 0.8 g/kg (dry matter weight) was proved as the optimum glucoamylase adding dosage in simultaneous saccharification and fermentation. Datas analysis indicated that the osmotic pressure was controlled strictly exhibited by high growth rate of yeast and high rate of ethanol formation comparing with other dosages, and 119.78 g/kg (15.07 %, v/v) ethanol equivalent to 90.16 % of theoretical yield was achieved in 64 hours.

Abstract: Mesoporous silica nanotube bundles with short channels were synthesized through a surfactant-templated process with the addition of dodecane. Transmission electron microscope (TEM) and high resolution scanning electron microscope (HRSEM) studies show that the channels of the silica nanotubes are parallel gathered in nano-size bundles. Each particle of these nano-size bundles contains less than 10 silica nanotubes. The length of the silica nanotube channel is about 200 nm while the pore size of the channels is about 11 nm. Dodecane solubilized in the hydrophobic cores of P123 micelles leads to large pore size and the unique bundle structure of the silica nanotubes.

Abstract: Fuel ethanol converted from biomass is a reliable substitute for fossil fuels, and lays people’s hope on the sustainable development in the fields of energy and climate. The limitation in source of raw materials and production cost are bottlenecks which restrain the wide use of fuel ethanol. This article makes an overview of the current research progress in the new technologies from the directions in the exploiting of raw materials and energy saving and polluted water emission reduction in the production process of fuel ethanol, and analyzes the potential application prospects and advantages of various new technologies.