摘要 :
We provide the evidence for the electro-optic nature of the transient reflectivity change (TRC) response from GaAs/GaSb/InAs heterostructures measured in ultrafast pump-probe experiments. The evidence is based on the correlation b...
展开
We provide the evidence for the electro-optic nature of the transient reflectivity change (TRC) response from GaAs/GaSb/InAs heterostructures measured in ultrafast pump-probe experiments. The evidence is based on the correlation between TRC and the transient electric-field-induced second harmonic generation change signals, which have been measured simultaneously. The TRC signal is induced through the second- and third-order nonlinearities by the interfacial dc electric fields originating from the charge separation of pump-excited carriers among the layers. The effect of the interface type between GaSb and InAs layers on the interfacial field strength was analyzed.
收起
摘要 :
Polyurethane foams have many applications and their fundamental properties have been widely investigated, mostly in relation to specific applications. In manufacturing, the need to produce homogeneous materials has led to the opti...
展开
Polyurethane foams have many applications and their fundamental properties have been widely investigated, mostly in relation to specific applications. In manufacturing, the need to produce homogeneous materials has led to the optimization of the formation processes and the understanding of the foam behaviour actually applies to homogeneous material. When applied to foundation remediation, expanding polyurethane foam is formed in the ground under conditions which are less controlled than in manufacturing processes or in the laboratory. Consequently, macrovoids and interfaces are created which result in a heterogeneous foam material. This paper investigates the microstructure and physical properties of expanded polyurethane foam injected in the ground using Scanning Electron Microscopy and physical testing. It is shown that the compressive strength is reduced by the resulting structural heterogeneity and the hydraulic conductivity is increased, but only to a value equivalent to that of a typical clay soil.
收起
摘要 :
The Raman spectra of Na_2-O-Al_2O_3-SiO_2 system with different Al_2O_3 contents (up to 25 mol /100) and with Na_2O/SiO_2 ratio from 1 to 2 have been measured at 1673 K. In the disilicate systems, the Rama spectra do not change si...
展开
The Raman spectra of Na_2-O-Al_2O_3-SiO_2 system with different Al_2O_3 contents (up to 25 mol /100) and with Na_2O/SiO_2 ratio from 1 to 2 have been measured at 1673 K. In the disilicate systems, the Rama spectra do not change significantly with increasing of Al_2O_3 content Except the development of the 500 cm~-1 band which is assigned to the three-dimensional network structur- Al unit consisted of Si~4+ and Al~3+ ions. Also it is found that Al~3+ ions possible interact with monomers and Form three-dimensional structures.
收起
摘要 :
We used scanning tunneling microscopy to investigate graphene formation on an SiC-on-insulator (SiC-OI) substrate. Annealing of an SiC-OI substrate with an SiC thickness of 1500 nm produced a graphene layer on the SiC surface. Whe...
展开
We used scanning tunneling microscopy to investigate graphene formation on an SiC-on-insulator (SiC-OI) substrate. Annealing of an SiC-OI substrate with an SiC thickness of 1500 nm produced a graphene layer on the SiC surface. When the thickness of the SiC film was 5 nm, a graphene layer was not formed on the SiC surface. However, after annealing a C-covered SiC-OI substrate with an SiC thickness of 5 nm, a graphene layer formed on the SiO2 surface.
收起
摘要 :
We provide the evidence for the hot-LO-phonon-assisted absorption at semiconductor heterointerfaces. The process is demonstrated with GaAs/GaSb interface when the photon energy is tuned below the band-gap energy for GaAs, but it i...
展开
We provide the evidence for the hot-LO-phonon-assisted absorption at semiconductor heterointerfaces. The process is demonstrated with GaAs/GaSb interface when the photon energy is tuned below the band-gap energy for GaAs, but it is in a great excess for G
收起
摘要 :
Compositional fluctuation (compositional inhomogeneity) in lead titanate zirconate (PZT) was found by X-ray diffraction measurement. The compositional fluctuation was considered to be caused from a size gap where neither mechanica...
展开
Compositional fluctuation (compositional inhomogeneity) in lead titanate zirconate (PZT) was found by X-ray diffraction measurement. The compositional fluctuation was considered to be caused from a size gap where neither mechanical mixing of raw materials nor diffusion during the sintering process is effective. A method to determine the dimension in which the compositional fluctuation occurs was developed. The homogenization process during the sintering process was clarified using this method.
收起
摘要 :
We measured HX-PES (Si Is) of ultra low energy ion implan-tion (I/I) samples combined with Ge pre-amorphizaiton ion implantation (Ge-PAl) before and after spike RTA, and compared it with that of plasma doping (PD) samples. As-dope...
展开
We measured HX-PES (Si Is) of ultra low energy ion implan-tion (I/I) samples combined with Ge pre-amorphizaiton ion implantation (Ge-PAl) before and after spike RTA, and compared it with that of plasma doping (PD) samples. As-doped I/I sample showed highe
收起
