in this paper, the main results are:a study of the finitely generated mv-algebras of continuous functions from the n-th power of the unit real interval i to i;a study of hopfian mv-algebras; anda category-theoretic study of the map sending an mv-algebra as above to the range of its generators (up to a suitable form of homeomorphism).

With the advent of global warming and energy crises, developing nanomaterial technologies into various nanodevices for energy harvesting has attracted a lot of attentions recently. Of which, nanogenerators by taking advantage of piezoelectric properties of nanowires (NWs) such as wurtzite compound semiconductors of ZnO [1], GaN [2], InN [3] and CdSe [4] can convert mechanical energy into electr...

I. ABSTRACT We present a Gallium Nitride (GaN) Lamb Wave resonator using a Phononic Crystal (PnC) to selectively confine elastic vibrations with wide-band spurious mode suppression. A unique feature of the design demonstrated here is a folded PnC structure to relax energy confinement in the non-resonant dimension and to enable routing access of piezoelectric transducers inside the resonant cavi...

We investigate exciton states theoretically in strained GaN/AlN quantum dots with wurtzite ~WZ! and zinc-blende ~ZB! crystal structures, as well as strained WZ GaN/AlGaN quantum dots. We show that the strain field significantly modifies the conductionand valence-band edges of GaN quantum dots. The piezoelectric field is found to govern excitonic properties of WZ GaN/AlN quantum dots, while it h...

Thermal conductivity in non-metallic crystalline materials results from cumulative contributions of phonons that have a broad range of mean free paths. Here we use high frequency surface temperature modulation that generates non-diffusive phonon transport to probe the phonon mean free path spectra of GaAs, GaN, AlN, and 4H-SiC at temperatures near 80 K, 150 K, 300 K, and 400 K. We find that pho...

Effects of process flows and device structures on the electrical properties of enhancement mode high electron mobility transistors (HEMTs) are investigated in this work. Except the demonstration of high threshold voltage (Vth) of 4.3V, the process window of the p-GaN residual thickness to ensure a steady operation current was estimated to be 10±5nm in our case. However, to achieve a high breakd...

Clean and As covered zinc-blende and wurtzite GaN surfaces have been investigated employing density-functional theory calculations. For clean GaN surfaces our calculations indicate the stability of several novel surface structures that are very different from those found on traditional III-V semiconductors. Adding impurities commonly present in significant concentrations during growth strongly ...

AlGaN/GaN/Be:GaN heterostructures have been grown by rf-plasma molecular beam epitaxy on freestanding semi-insulating GaN substrates, employing unintentionally-doped (UID) GaN buffer layers with thicknesses, dUID, varying between 50 nm and 500 nm. We have found that the heterostructures with UID buffers thicker than 200 nm exhibit much improved Hall properties and inter-device isolation current...

Wide-gap semiconductors have received significant attention for their advantages over existing semiconductors in energy-efficient power devices. To realize stable and reliable wide-gap semiconductor devices, the basic physical properties, such as the electric properties on the surface and at the interface, should be revealed. Here, we report visualization of terahertz (THz) emission from the su...