The molecular beam epitaxial (MBE) growth and postgrowth annealing of InAs/GaAs(001) quantum dots were investigated by grazing-incidence X-ray diffraction using a diffractometer integrated with an MBE apparatus. The use of synchrotron radiation and a two-dimensional X-ray detector enabled X-ray diffraction measurements on the internal strains and height of dots at a rate of less than 10 s per f...

Gas-source molecular-beam epitaxy (MBE) has been used to grow SiGe alloys with S&H6 and GeH4 as sources on (100) Si substrates. Single-crystalline epilayers with Ge composition as high as 33% have been produced at 610 “C, the lowest temperature hitherto used for gas-source SiGe MBE. Growth parameters, growth modes, and the structural characteristics have been studied by a variety of in situ and...

Three different elements, Silicon, Selenium, and Tellurium, are ion-implanted in Gallium arsenide to form a conducting layer that serves as back-gate molecular beam epitaxy (MBE) overgrown two-dimensional electron gas (2DEG). While the heavy ion Tellurium creates too many damages gallium layer, both Silicon Selenium show promising results combined with MBE-grown high-quality 2DEGs. Similar 2DEG...

The dN/dS ratio between nonsynonymous and synonymous substitution rates has been used extensively to identify codon positions involved in adaptive processes. However, the accuracy of this approach has been questioned and very few studies have attempted to validate experimentally its predictions. Using the coat protein (CP) of Potato virus Y (PVY; genus Potyvirus, family Potyviridae) as a case s...

This paper presents improved HMM/SVM methods for a twostage phoneme segmentation framework, which tries to imitate the human phoneme segmentation process. The first stage performs hidden Markov model (HMM) forced alignment according to the minimum boundary error (MBE) criterion. The objective is to align a phoneme sequence of a speech utterance with its acoustic signal counterpart based on MBE-...

A numerical solution of the modified Burgers' equation (MBE) is obtained by using quartic B-spline subdomain finite element method (SFEM) over which the nonlinear term is locally linearized and using quartic B-spline differential quadrature (QBDQM) method. The accuracy and efficiency of the methods are discussed by computing L 2 and L ∞ error norms. Comparisons are made with those of some earli...

I.I.T. Bombay, in collaboration with C.R.L., B.E.L., is working on developing a speech codec to provide communication quality speech at low bit rates. The codec is required to be robust to acoustic background noise and to channel errors. A sinusoidal coder based on the MBE (Multiband Excitation) model has been adopted as the basic speech representation due to its compact parameter set and the r...

Single quantum wells In0.53Ga0.47As/Ga0.47In0.53N0.021As0.949Sb0.03 /In0.53Ga0.47As with room-temperature photoluminescence peak wavelength at 2.04 mm were grown on InP substrate by solid-source molecular-beam epitaxy ~MBE!. In situ reflection high-energy electron diffraction was used to monitor the MBE growth. Double-crystal high-resolution x-ray diffraction and secondary ion mass spectrometry...

A series of AlxGa(1−x)As ternary alloys were grown by molecular beam epitaxy (MBE) at the technologically relevant composition range, x < 0.45, and characterized using spectroscopic ellipsometry to provide accurate refractive index values in wavelength region below bandgap. Particular attention is given O-band C-band telecommunication wavelengths around 1.3 µm 1.55 µm, as well 825 nm. MB...