민치에흐린 교수

Abstract We discuss first-principles topological electronic structure of noncentrosymmetric SrSi 2 materials class based on the hybrid exchange-correlation functional. Topological phase diagram of SrSi 2 is mapped out as a function of the lattice constant with focus on the semimetal order. A tunable double-Weyl Fermion state in Sr 1− x Ca x Si 2 and Sr 1− x Ba x Si 2 alloys is identified. Ca doping in SrSi 2 is shown to yield a double-Weyl semimetal with a large Fermi arc length, while Ba doping

Abstract The reaction of CH 2 O with NO 2 has been studied with a shock tube equipped with two stabilized ew CO lasers. The production of CO, NO, and H 2 O has been monitored with the CO lasers in the temperature range of 1140–1650 K using three different Ar‐diluted CH 2 O‐NO 2 mixtures. Kinetic modeling and sensitivity analysis of the observed CO, NO, and H 2 O production profiles over the entire range of reaction conditions employed indicate that the bimolecular metathetical reaction, NO 2 + C

A relativistic field-emission-limited diode employing a high-transparency mesh anode is investigated via a self-consistent approach. The field emission process is described quantum mechanically by the Fowler–Nordheim equation. The cathode plasma and surface properties are considered within the framework of the effective work function approximation. Space-charge effects are described by Poisson’s equation including relativistic effects. Ionization effects at the high-transparency mesh anode are i

We have studied for the first time the kinetics and mechanism for the sublimation/decomposition of NH 4 ClO 4 by first-principles calculations, using a generalized gradient approximation with the plane-wave density functional theory. Supercells containing 4, 8, and 16 NH 4 ClO 4 units were used; the predicted enthalpic change for solid NH 4 ClO 4 to gaseous NH 3 and HClO 4 is 45.0 ± 1.5 kcal/mol. The calculated desorption activation energies for NH 3, HClO 4, and H 3 N···HOClO 3 molecular comple

The kinetics and mechanism of the CH3 + O reaction and related isomerization-decomposition of CH3O and CH2OH radicals have been studied by ab initio molecular orbital theory based on the CCSD(T)/aug-cc-pVTZ//CCSD/aug-cc-pVTZ, CCSD/aug-cc-pVDZ, and G2M//B3LYP/6-311+G(3df,2p) levels of theory. The predicted potential energy surface of the CH3 + O reaction shows that the CHO + H2 products can be directly generated from CH3O by the TS3 → LM1 → TS7 → LM2 → TS4 path, in which both LM1 and LM2 are very

Abstract An ab initio molecular orbital study of the potential energy surface of the C 6 H 5 O + O reaction was performed at the (PUMP3/6‐31G*//UHF/6‐31G*) level of theory. Various reaction channels were considered. The most favorable mechanism, la and Ib, start from the attachment of the oxygen atom to the carbon atom of the C 6 ring in the ortho ‐ or para position with respect to CO, taking place without activation energy. Then, either hydrogen elimination by mechanism Ia or 1,2‐H shift from t

Terahertz (THz), waves i.e., electromagnetic radiation in the frequency extending from 0.1 to 10 THz (wavelengths of 3 mm down to 0.03 mm), have been used to characterize the electronic, vibrational, and compositional properties of solid, liquid, and gas phase materials during the past decade. More and more applications in imaging science and technology call for the well development of THz wave sources. Amplification and generation of a high frequency electromagnetic wave are a common interest o

Presents the guest editorial for this issue of the publication.

Space-charge effects of electrons and ions on the steady state of a field-emission-limited diode (FELD) are investigated via a self-consistent approach. The field-emission process is described quantum mechanically by the Fowler–Nordheim equation. The cathode plasma and surface properties are considered within the framework of the effective work function approximation. Ionization effects at the anode as well as electron space-charge effects are described by Poisson’s equation. The numerical calcu