In this work,Bi2Te3 films（250 nm） are fabricated on Si O2/Si substrates by radio frequency（RF） magnetron sputtering at room temperature,and the prepared films are annealed over the temperature range of 200 °C...In this work,Bi2Te3 films（250 nm） are fabricated on Si O2/Si substrates by radio frequency（RF） magnetron sputtering at room temperature,and the prepared films are annealed over the temperature range of 200 °C to 400 °C.Crystallinity and electrical properties of the films can be tuned correspondingly.The power factors of Bi2Te3 films of 0.85 μW/K2 cm to 11.43 μW/K2 cm were achieved after annealing.The infrared reflectance measurements from 2.5 μm to 5.0 μm demonstrate that there is also a slight red-shift of the plasma oscillation frequency in the Bi2Te3 films.By means of plasmonic calculations,we attribute the red-shift of absorption peaks to the reduction of carrier concentration and the change of effective mass of Bi2Te3 films with the increased annealing temperature.展开更多
The development of simulation model and benchmark work have expanded in the past decade and many models and soft ware are introduced. The leading software "Hearts’ developed by Prof Inoue[1] and several other ha...The development of simulation model and benchmark work have expanded in the past decade and many models and soft ware are introduced. The leading software "Hearts’ developed by Prof Inoue[1] and several other have proved the effectiveness as the pre-production simulation work at many part of heat treatment processes[2-10]. Although, numerous other models and simulation studies dealt with many fundamental factors are reported at many conferences except very few models have not completed three dimensional computation methods, or lack of validation work to evaluate their tools exactly. In this paper, several distortion case studies will be introduced and the needs of fundamental study of distortion and internationally collaborative program on model evaluation and construction of materials database are proposed.展开更多
β-quenching a Zr-1.15 wt％Cr-0.10 wt％Fe alloy produces a martensitic or a Widmanst(a|¨)tten transforma- tion morphology,or a mixture of the two,depending on the cooling rate.For the Widmanst(a|¨)tten struc...β-quenching a Zr-1.15 wt％Cr-0.10 wt％Fe alloy produces a martensitic or a Widmanst(a|¨)tten transforma- tion morphology,or a mixture of the two,depending on the cooling rate.For the Widmanst(a|¨)tten structure,or the mixed martensitic-Widmanst(a|¨)itten structure,a grain boundary phase is observed at most prior-β grain boundaries.X-ray line broadening analysis and the thermoelectric power(TEP)measurements of these quenched samples show that not only the solubility of alloying elements in α-Zr matrix,but also substructure (microstrain,crystallite size and dislocation density)have an effect on TEP.Thus,TEP measurements are very well suited for following the structural transformations taking place in Zr alloys during fabrication.展开更多
This paper studies the application of renewable energy sources in wastewater treatment plants to achieve self-sustain- ability of power. The data of wastewater treatment plant in the rural city of Toukh-EGYPT are pres...This paper studies the application of renewable energy sources in wastewater treatment plants to achieve self-sustain- ability of power. The data of wastewater treatment plant in the rural city of Toukh-EGYPT are presented as a case-study. The primary objective is to provide an entirely renewable standalone power system, which satisfies lowest possible emissions with the minimum lifecycle cost. Mass balance principle is applied on the biodegradable components in the wastewater to evaluate the volume of digester gas that is produced from sludge through anaerobic digestion process. Using digester gas as a fuel lead to study combined-heat-and-power technologies, where fuel cell is selected in order to abide by the low emissions constraint. The study assessed the electrical power obtained from fuel cell and the utilization of the exhausted heat energy for additional electrical power production using a micro-turbine. After covering the major part of load demand, the use of other renewable energy sources was studied. The strength of both solar and wind energy was determined by the case-study location. Hybrid optimization model for electric renewable (HOMER) software was used to simulate the hybrid system composed of combined-heat-and-power units, wind turbines and photovoltaic systems. Simulation results gave the best system configuration and optimum size of each component beside the detailed electrical and cost analysis of the model.展开更多
42Cr Mo钢已成功地用作小功率(2 MW及以下)风电偏航轴承套圈用钢,但由于其有限的淬透性,无法满足大功率风电偏航轴承套圈用钢的要求,因此,研究中引入40Cr Ni Mo钢和硼微合金化42Cr Mn Mo B钢进行对比分析。研究42Cr Mn Mo B钢、40Cr Ni...42Cr Mo钢已成功地用作小功率(2 MW及以下)风电偏航轴承套圈用钢,但由于其有限的淬透性,无法满足大功率风电偏航轴承套圈用钢的要求,因此,研究中引入40Cr Ni Mo钢和硼微合金化42Cr Mn Mo B钢进行对比分析。研究42Cr Mn Mo B钢、40Cr Ni Mo钢和42Cr Mo钢的淬透性,利用DEFORM3D模拟软件对5 MW风电偏航轴承套圈壁厚1/4位置处的油冷速率进行模拟,并利用模拟热处理炉对三种钢进行模拟热处理,随后对试验钢进行常规力学性能的测试。结果表明,42Cr Mn Mo B钢在端淬距离为85 mm位置处的硬度值为46 HRC,油淬后的理想临界直径约为160 mm,远高于42Cr Mo钢在85 mm位置处的29 HRC和43 mm的理想临界直径;经DEFORM3D模拟软件模拟的5 MW级风电偏航轴承壁厚1/4位置处的平均油冷速率约为0.7℃/s;在模拟油冷并经590℃回火1 h处理后42Cr Mn Mo B钢各项力学性能均能满足5 MW级风电偏航轴承套圈用钢的性能要求,具有应用于大功率风电偏航轴承套圈中的潜能。展开更多
基金supported by the National Natural Science Foundation of China under Grant No.51025208Program for Changjiang Scholars and Innovative Research Team in University under Grant No.IRT1309
文摘In this work,Bi2Te3 films（250 nm） are fabricated on Si O2/Si substrates by radio frequency（RF） magnetron sputtering at room temperature,and the prepared films are annealed over the temperature range of 200 °C to 400 °C.Crystallinity and electrical properties of the films can be tuned correspondingly.The power factors of Bi2Te3 films of 0.85 μW/K2 cm to 11.43 μW/K2 cm were achieved after annealing.The infrared reflectance measurements from 2.5 μm to 5.0 μm demonstrate that there is also a slight red-shift of the plasma oscillation frequency in the Bi2Te3 films.By means of plasmonic calculations,we attribute the red-shift of absorption peaks to the reduction of carrier concentration and the change of effective mass of Bi2Te3 films with the increased annealing temperature.
文摘The development of simulation model and benchmark work have expanded in the past decade and many models and soft ware are introduced. The leading software "Hearts’ developed by Prof Inoue[1] and several other have proved the effectiveness as the pre-production simulation work at many part of heat treatment processes[2-10]. Although, numerous other models and simulation studies dealt with many fundamental factors are reported at many conferences except very few models have not completed three dimensional computation methods, or lack of validation work to evaluate their tools exactly. In this paper, several distortion case studies will be introduced and the needs of fundamental study of distortion and internationally collaborative program on model evaluation and construction of materials database are proposed.
文摘β-quenching a Zr-1.15 wt％Cr-0.10 wt％Fe alloy produces a martensitic or a Widmanst(a|¨)tten transforma- tion morphology,or a mixture of the two,depending on the cooling rate.For the Widmanst(a|¨)tten structure,or the mixed martensitic-Widmanst(a|¨)itten structure,a grain boundary phase is observed at most prior-β grain boundaries.X-ray line broadening analysis and the thermoelectric power(TEP)measurements of these quenched samples show that not only the solubility of alloying elements in α-Zr matrix,but also substructure (microstrain,crystallite size and dislocation density)have an effect on TEP.Thus,TEP measurements are very well suited for following the structural transformations taking place in Zr alloys during fabrication.
文摘This paper studies the application of renewable energy sources in wastewater treatment plants to achieve self-sustain- ability of power. The data of wastewater treatment plant in the rural city of Toukh-EGYPT are presented as a case-study. The primary objective is to provide an entirely renewable standalone power system, which satisfies lowest possible emissions with the minimum lifecycle cost. Mass balance principle is applied on the biodegradable components in the wastewater to evaluate the volume of digester gas that is produced from sludge through anaerobic digestion process. Using digester gas as a fuel lead to study combined-heat-and-power technologies, where fuel cell is selected in order to abide by the low emissions constraint. The study assessed the electrical power obtained from fuel cell and the utilization of the exhausted heat energy for additional electrical power production using a micro-turbine. After covering the major part of load demand, the use of other renewable energy sources was studied. The strength of both solar and wind energy was determined by the case-study location. Hybrid optimization model for electric renewable (HOMER) software was used to simulate the hybrid system composed of combined-heat-and-power units, wind turbines and photovoltaic systems. Simulation results gave the best system configuration and optimum size of each component beside the detailed electrical and cost analysis of the model.
