The structural and optical characteristics of InP-based compressively strained InGaAs quantum wells have been significantly improved by using gas source molecular beam epitaxy grown InAs/Ino.53Ga0.47As digital alloy t...The structural and optical characteristics of InP-based compressively strained InGaAs quantum wells have been significantly improved by using gas source molecular beam epitaxy grown InAs/Ino.53Ga0.47As digital alloy triangular well layers and tensile Ino.53Ga0.47As/InAiGaAs digital alloy barrier layers. The x-ray diffraction and transmission electron microscope characterisations indicate that the digital alloy structures present favourable lattice quality. Photo- luminescence （PL） and electroluminescence （EL） measurements show that the use of digital alloy barriers offers better optical characteristics than that of conventional random alloy barriers. A significantly improved PL signal of around 2.1μm at 300 K and an EL signal of around 1.95μm at 100 K have been obtained.展开更多
The simulation of slope failures,including both failure initiation and development,has been modelled using the material point method（MPM）.Numerical case studies involving various slope angles,heterogeneity and rainf...The simulation of slope failures,including both failure initiation and development,has been modelled using the material point method（MPM）.Numerical case studies involving various slope angles,heterogeneity and rainfall infiltration are presented.It is demonstrated that,by utilising a constitutive model which encompasses,in a simplified manner,both pre-and post-failure behaviour,the material point method is able to simulate commonly observed failure modes.This is a step towards being able to better quantify slope failure consequence and risk.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 60876034)the National Basic Research Program of China (Grant No. 2006CB604903)
文摘The structural and optical characteristics of InP-based compressively strained InGaAs quantum wells have been significantly improved by using gas source molecular beam epitaxy grown InAs/Ino.53Ga0.47As digital alloy triangular well layers and tensile Ino.53Ga0.47As/InAiGaAs digital alloy barrier layers. The x-ray diffraction and transmission electron microscope characterisations indicate that the digital alloy structures present favourable lattice quality. Photo- luminescence （PL） and electroluminescence （EL） measurements show that the use of digital alloy barriers offers better optical characteristics than that of conventional random alloy barriers. A significantly improved PL signal of around 2.1μm at 300 K and an EL signal of around 1.95μm at 100 K have been obtained.
基金supported by the Marie Curie Career Integration Grant(No.333177)the "100 Talents" programme of the Chinese Academy of Science+1 种基金the China Scholarship Councilthe Geo-Engineering Section of Delft University of Technology
文摘The simulation of slope failures,including both failure initiation and development,has been modelled using the material point method（MPM）.Numerical case studies involving various slope angles,heterogeneity and rainfall infiltration are presented.It is demonstrated that,by utilising a constitutive model which encompasses,in a simplified manner,both pre-and post-failure behaviour,the material point method is able to simulate commonly observed failure modes.This is a step towards being able to better quantify slope failure consequence and risk.
