Electrical properties of unintentionally doped p-type Ga0.95In0.05N0.013As0.987 quaternary alloys grown by metal–organic vapor-phase epitaxy have been investigated by Hall-effect and photoconductivity measurements. Persistent photoconductivity ~PPC! has been observed in this material at temperatures T,320 K. The PPC buildup and decay kinetics have been systematically measured at different tempe...

Oxidative 1,2- and 1,3- alkyl shifts mediated by a hypervalent iodine reagent were performed on simple and inexpensive phenol derivatives. These transpositions enable rapid redesign of the main aromatic skeleton to generate good yields of highly functionalized scaffolds containing a prochiral dienone system, a quaternary carbon center connected to as many as four sp(2) centers, and a carbonyl f...

The parallel branching program machine (PBM128) consists of 128 branching program machines (BMs) and a programmable interconnection. To represent logic functions on BMs, we use quaternary decision diagrams. To evaluate functions, we use 3-address quaternary branch instructions. We realized many benchmark functions on the PBM128, and compared its memory size, computation time, and power consumpt...

The aim of this study was to develop a derivative of chitosan as pharmaceutical excipient used in sustained-release matrix tablets of poorly soluble drugs. A water-soluble quaternary ammonium carboxymethylchitosan was synthesized by a two-step reaction with carboxymethylchitosan (CMCTS), decylalkyl dimethyl ammonium and epichlorohydrin. The elemental analysis showed that the target product with...

An analytical approach is presented to determine the impact of time selective fading, timing jitter and additive white Gaussian noise (AWGN) on the bit error rate (BER) performance of an orthogonal frequencydivision multiplexing (OFDM) system with differential quaternary phase-shift keying (DQPSK), differential phaseshift keying (DPSK) and quaternary phase-shift keying (QPSK) modulation. The ex...

Protein allostery is essential for vital activities. Allosteric regulation of human hemoglobin (HbA) with two quaternary states T and R has been a paradigm of allosteric structural regulation of proteins. It is widely accepted that oxygen molecules (O2) act as a "site-specific" homotropic effector, or the successive O2 binding to the heme brings about the quaternary regulation. However, here we...

Lithiation of carbamates followed by borylation provides a powerful method for the homologation of boron reagents. However, when applied to hindered systems (secondary carbamates with tBu-boronic esters) for the construction of two quaternary centers, this methodology fails. Instead, using mixed boranes (tBuBMe2), the synthesis of adjacent quaternary stereogenic centers with full stereocontrol ...