397 research outputs found
Parametric Amplification and Generation of Surface Acoustic Waves on a Monolithic MIS Structure
The effect of electromechanical coupling on the strain in AlGaN/GaN heterojunction field effect transistors
The strain in AlGaN/GaN heterojunction field-effect transistors (HFETs) is
examined theoretically in the context of the fully-coupled equation of state
for piezoelectric materials. Using a simple analytical model, it is shown that,
in the absence of a two-dimensional electron gas (2DEG), the out-of-plane
strain obtained without electromechanical coupling is in error by about 30% for
an Al fraction of 0.3. This result has consequences for the calculation of
quantities that depend directly on the strain tensor. These quantities include
the eigenstates and electrostatic potential in AlGaN/GaN heterostructures. It
is shown that for an HFET, the electromechanical coupling is screened by the
2DEG. Results for the electromechanical model, including the 2DEG, indicate
that the standard (decoupled) strain model is a reasonable approximation for
HFET calculataions. The analytical results are supported by a self-consistent
Schr\"odinger-Poisson calculation that includes the fully-coupled equation of
state together with the charge-balance equation.Comment: 6 figures, revte
The Ecm11-Gmc2 complex promotes synaptonemal complex formation through assembly of transverse filaments in budding yeast
During meiosis, homologous chromosomes pair at close proximity to form the synaptonemal complex (SC). This association is mediated by transverse filament proteins that hold the axes of homologous chromosomes together along their entire length. Transverse filament proteins are highly aggregative and can form an aberrant aggregate called the polycomplex that is unassociated with chromosomes. Here, we show that the Ecm11-Gmc2 complex is a novel SC component, functioning to facilitate assembly of the yeast transverse filament protein, Zip1. Ecm11 and Gmc2 initially localize to the synapsis initiation sites, then throughout the synapsed regions of paired homologous chromosomes. The absence of either Ecm11 or Gmc2 substantially compromises the chromosomal assembly of Zip1 as well as polycomplex formation, indicating that the complex is required for extensive Zip1 polymerization. We also show that Ecm11 is SUMOylated in a Gmc2-dependent manner. Remarkably, in the unSUMOylatable ecm11 mutant, assembly of chromosomal Zip1 remained compromised while polycomplex formation became frequent. We propose that the Ecm11-Gmc2 complex facilitates the assembly of Zip1 and that SUMOylation of Ecm11 is critical for ensuring chromosomal assembly of Zip1, thus suppressing polycomplex formation
Measurement of interface-state parameters near the band edge at the Si/SiO2 interface by the conductance method
Traial on a ToF Measurement of Gamma-rays and Neutrons by a Diamond Radiation Detector with Fast Time Response
Trial of Fast Neutral Particles and Neutron Measurement by a Synthetic Diamond Radiation Detector
Traial on a ToF Measurement of Gamma-rays and Neutrons by a Diamond Radiation Detector with Fast Time Response
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