Applying design patterns while developing a software system can improve its non-functional properties, such as extensibility and loose coupling. Precise specification of structure and behaviour communicates the invariants imposed by a pattern on a conforming implementation and enables formal software verification. Many existing design-pattern specification languages (DPSLs) focus on class struc...

Boron arsenide, the typically-ignored member of the III–V arsenide series BAs–AlAs–GaAs– InAs is found to resemble silicon electronically: its Γ conduction band minimum is p-like (Γ15), not s-like (Γ1c), it has an X1c-like indirect band gap, and its bond charge is distributed almost equally on the two atoms in the unit cell, exhibiting nearly perfect covalency. The reasons for these are tracked...

We present a new technique allowing us to build freely suspended two-dimensional electron gases from AlGaAs/GaAs/AlAs heterostructures. This technique relies on an MBE-grown structures that includes a sacrificial layer. ( 1998 Elsevier Science B.V. All rights reserved.

Using two optical techniques, we have studied the hot electron–optical phonon interactions in GaAs/AlxGa12xAs multiplequantum wells. Raman scattering measurements at 15 K are presented for the Al composition of xˆ 0.3, 0.5, 0.7 and 1.0. The GaAs-like and AlAs-like phonon frequencies of the first-order modes are also measured as a function of Al composition. The optical phonon energies emitted b...