AlGaN/GaN high electron mobility transistors (HEMTs) are now receiving great attention because of their potential applications to high-power and high-frequency devices (Mishra et al., 2008). An output power of more than 32 W/mm is reported at 4 GHz for the 0.55 μm gate-length device (Wu et al., 2004), and a current-gain cutoff frequency (fT) of 163 GHz is obtained for 0.06 μm gate length (Higas...

This paper begins a series studying D-modules on the Feigin-Frenkel semi-infinite flag variety from the perspective of the Beilinson-Drinfeld factorization (or chiral) theory. Here we calculate Whittaker-twisted cohomology groups of Zastava spaces, which are certain finite-dimensional subvarieties of the affine Grassmannian. We show that such cohomology groups realize the nilradical of a Borel ...

We develop a mixed finite-element approximation scheme for Kirchhoff plate theory based on the reformulation of Kirchhoff plate theory of Ortiz and Morris [1]. In this reformulation the moment-equilibrium problem for the rotations is in direct analogy to the problem of incompressible two-dimensional elasticity. This analogy in turn opens the way for the application of diamond approximation sche...

Among the motions of a fluid over a plane wall, the Stokes’ problems as well as the motion induced by a constantly accelerating plate have been extensively studied in the literature. However, the first closed-form solutions for the motion of a viscous fluid over an oscillating plate have been late enough obtained by Erdogan [1]. These solutions, as well as those corresponding to the fluid motio...

The inception of plate tectonics on Earth and its subsequent evolution are discussed on the basis of theoretical considerations and observational constraints. The likelihood of plate tectonics in the past depends on what mechanism is responsible for the relatively constant surface heat flux that is indicated by the likely thermal history of Earth. The continuous operation of plate tectonics thr...

Low-frequency noise pollution in substations has a significant impact on the physical and mental health of workers. Reduction low-frequency is an urgent problem to solve for researchers. In this paper, different structures Al 2 O 3 -polyurethane composites micro-perforated plate were constructed, effects cavity depth, perforated plate, foam position sound absorption properties comprehensively i...

Due to the medium and small damping characteristics of the hard coating compared with viscoelastic materials, the classical modal strain energy (CMSE) method cannot be applied to the prediction of damping characteristics of hard-coating composite structure directly. In this study, the CMSE method was modified in order to be suitable for this calculation, and then the damping optimization of the...

Partitioning of horizontal deformation between localized and distributed modes in regions of oblique tectonic convergence is, in many cases, hard to quantify. Here we use the geometry of river basins and numerical modeling to evaluate modes and rates of horizontal deformation associated with the Arabia-Sinai relative plate motion in Lebanon. We focus on river basins that drain Mount Lebanon to ...

a r t i c l e i n f o a b s t r a c t The elevation of an orogenic belt is commonly related to crustal/lithosphere thickening. Here, we discuss the Apennines as an example to show that topography at a plate margin may be controlled not only by isostatic adjustment but also by dynamic, mantle-driven processes. Using recent structural constraints for the crust and mantle we find that the expected...