Investigations on the defect structures for Mn in CdSe nanocrystals and bulk materials and the criterion of occupation for Mn in CdX (X = S, Se, Te) nanocrystals.

The spin Hamiltonian parameters and defect structures are theoretically studied for the substitutional Mn at the core of CdSe nanocrystals and in the bulk materials from the perturbation calculations of spin Hamiltonian parameters for trigonal tetrahedral 3d clusters. Both the crystal-field and charge transfer contributions are taken into account in the calculations from the cluster approach. The impurity-ligand bond angles are found to be about 1.

Assessing the Role of Gaseous Chlorine Dioxide in Modulating the Postharvest Ripening of Keitt Mangoes through the Induction of Ethylene Biosynthesis.

Consumer acceptance of Keitt mangoes ( L.) is significantly affected by their slow postharvest ripening. This work used gaseous chlorine dioxide (ClO(g)) to prepare the ready-to-eat Keitt mango and explored the potential mechanisms for the mango ripening.

Theoretical investigations on the defect structures and g factors for V in 30PbO-5Bi O -(65-x)SiO glasses at different concentrations.

For 3d (V ) impurity in 30PbO-5Bi O -(65-x)SiO glass systems with different concentrations x of V2O5, the defect structures and gyromagnetic factors are theoretically investigated by using the perturbation formulas of g factors for a tetragonally compressed octahedral 3d group. The concentration dependences of d-d transition band and g factors are suitably explained from the Fourier type concentration functions of the cubic crystal field parameter Dq, covalency factor N and relative tetragonal compression ratio ρ. The above concentration dependences of these quantities are suitably illustrated by the modifications of the local crystal field strength and electron cloud distribution with increasing x.

Single noble metals (Pd, Pt and Ir) anchored Janus MoSSe monolayers: Efficient oxygen reduction/evolution reaction bifunctional electrocatalysts and harmful gas detectors.

The binding properties of single noble metal atoms (Pd, Pt and Ir) anchored Janus MoSSe monolayers (MLs), the catalytic activity of Pd- and Pt-MoSSe in oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) as well as the adsorption behaviors of Ir-MoSSe for harmful NO, CO and NH molecules are systematically studied from the first-principles calculations. Current results reflect the ascending order (Pd-MoSSe < Pt-MoSSe < Ir-MoSSe) of stability and binding strength as well as the tunable electronic properties of Janus MoSSe ML by anchoring single Pd, Pt and Ir atoms. Pd- and Pt-MoSSe exhibit excellent bifunctional catalytic performance, especially the former having lower overpotentials 0.

Theoretical studies of the concentration dependences of d-d transition band, g factors, and local distortion for V in Li O-PbO-B O -P O glasses.

In this work, the g factors, d-d transition band, local distortion, and their concentration dependences for impurity V in 20Li O-20PbO-45B O -(15 - x)P O :V O (0 ≤ x ≤ 2.5 mol%) glasses are theoretically investigated by using perturbation formulas of g factors for a tetragonally compressed octahedral 3d cluster. In the light of the cubic polynomial concentration functions for cubic field parameter D , covalency factor N, and relative tetragonal compression ratio ρ, the calculated concentration dependences of d-d transition band and g factors for V show good agreement with the experimental data.

Density functional theory calculations of copper-doped rutile crystals: Local structural, electronic, optical, and electron paramagnetic resonance properties.

The local structural, electronic, optical, and electron paramagnetic resonance (EPR) properties are uniformly studied for Cu -doped rutile (TiO ) crystals by using the density functional theory (DFT) calculations. The local cation-oxygen bond lengths and planar bond angle, band gap, Mulliken charge and overlapping population, density of state (DOS), and UV-Vis absorption spectra are calculated for pure and copper-doped rutile. The smaller overlapping population of Cu-O bonds in the doped system than Ti-O bonds in pure rutile reflects weaker orbital admixtures or covalency of the former.

Atomic Ni and Cu co-anchored 3D nanoporous graphene as an efficient oxygen reduction electrocatalyst for zinc-air batteries.

Highly active, cost-effective and durable electrocatalysts for the oxygen reduction reaction (ORR) are critically important for renewable energy conversion and storage. Here we report a 3D bicontinuous nitrogen doped nanoporous graphene electrocatalyst co-anchoring with atomically dispersed nickel and copper atoms ((Ni,Cu)-NG) as a highly active single-atom ORR catalyst, fabricated by the combination of chemical vapor deposition and high temperature gas transportation. The resultant (Ni,Cu)-NG exhibits an exceptional ORR activity in alkaline electrolytes, comparable to the Pt-based benchmarks, from the synergistic effect of the CuNx and NiNx complexes.

Exploring promising gas sensing and highly active catalysts for CO oxidation: transition-metal (Fe, Co and Ni) adsorbed Janus MoSSe monolayers.

From first-principles calculations, the transition-metal (TM) atom (Fe, Co and Ni) adsorbed Janus MoSSe monolayer, toxic gas molecules (CO, NH3 and H2S) adsorbed on the Ni-MoSSe monolayer and CO catalytic oxidation on the Fe-MoSSe monolayer are systematically investigated. An increasing order (Fe-MoSSe < Co-MoSSe < Ni-MoSSe) is found for the stability and band gap of the TM atom adsorbed Janus MoSSe monolayer. These toxic gas molecules are found to be weakly physisorbed and strongly chemisorbed on the pristine and Ni-MoSSe monolayers, respectively.

Studies on the local structure and spin Hamiltonian parameters for V in Na O-PbO-Bi O -SiO glass ceramics.

The local structure, d-d transition band, and spin Hamiltonian parameters (SHPs) are theoretically studied for the V probe in Na O-PbO-Bi O -SiO (NPBS) glass ceramics containing V O dopant with various concentration x (0 ≤ x ≤ 5 mol%) by using the perturbation formulas of the SHPs for tetragonally compressed octahedral 3d clusters. The first decreasing (or increasing) and then increasing (or decreasing) d-d transition band (= 10 D ) and hyperfine structure constants A and A (or g factors g and g ) with x can be suitably simulated with the similarly varying Fourier type concentration functions of cubic field parameter D , covalence factor N, core polarization constant κ, and reduction factor H (or relative tetragonal compression ratio ρ), with the minima (or maxima) at the middle concentration x = 3 mol%, respectively. The above concentration variations of SHPs and the related quantities may originate from the modifications of local crystal field strength, tetragonal compression, and electron cloud distribution near the impurity V with x, corresponding to the highest [V ]/[V ] ratio at 3 mol%.

The freezing Rènyi quantum discord.

As a universal quantum character of quantum correlation, the freezing phenomenon is researched by geometry and quantum discord methods, respectively. In this paper, the properties of Rènyi discord is studied for two independent Dimer System coupled to two correlated Fermi-spin environments under the non-Markovian condition. We further demonstrate that the freezing behaviors still exist for Rènyi discord and study the effects of different parameters on this behaviors.

Studies on the local structures for the trigonal Ni centers in cathode materials LiAl Co O (y = 0, 0.1, 0.5, and 0.8).

The local angular distortions Δθ are theoretically studied for the various Ni centers in LiAl Co O at different Al concentrations (y = 0, 0.1, 0.5, and 0.

DFT calculations of the defect structures, electronic structures, and EPR parameters for three Rh centers in AgCl.

The local structures for various Rh centers in AgCl are theoretically studied using density functional theory (DFT) with periodic CP2K program. Through geometry optimizing, the stable ground states with minimal energies and electronic structures are obtained for the tetragonally elongated (T ), orthorhombically elongated (O ), and tetragonally compressed (T ) centers, and the corresponding g and hyperfine coupling tensors are calculated in ORCA level. The calculations reveal obvious Jahn-Teller elongation distortions of about 0.

Investigations of the local distortions and EPR parameters for Cu in xNa O-(30-x)K O-70B O (5 ≤ x ≤ 25 mol%) glasses.

The local distortions and electron paramagnetic resonance parameters for Cu in the mixed alkali borate glasses xNa O-(30-x)K O-70B O (5 ≤ x ≤ 25 mol%) are theoretically studied with distinct modifier Na O compositions x. Owing to the Jahn-Teller effect, the octahedral [CuO ] clusters show significant tetragonal elongation ratios p ~19% along the C axis. With the increase of composition x, the cubic field parameter Dq and the orbital reduction factor k exhibit linearly and quasi-linearly decreasing tendencies, respectively, whereas the relative tetragonal elongation ratio p has quasi-linearly increasing rule with some fluctuations, leading to the minima of g factors at x = 10 mol%.

Theoretical studies of the copper gyromagnetic factors for three novel Cu coordination polymers with bi-triazole ligand.

The copper electron paramagnetic resonance gyromagnetic factors are theoretically studied for three novel Cu coordination polymers [Cu(XL)(NO ) ] (1), {[Cu(XL)(4,4'-bpy)(NO ) ]•CH CN} (1a) and {[Cu(XL) ](NO ) •3.5H O} (2) with bi-triazole ligand (XL) = N,N'-bicyclo[2.2.

Implementation of the CMOS MEMS condenser microphone with corrugated metal diaphragm and silicon back-plate.

This study reports a CMOS-MEMS condenser microphone implemented using the standard thin film stacking of 0.35 μm UMC CMOS 3.3/5.

Investigations on the electron paramagnetic resonance parameters for Mn2+ in the ABF3 fluoroperovskites.

The electron paramagnetic resonance (EPR) parameters (g factor, the hyperfine structure constant A and the superhyperfine parameters A' and B') for Mn(2+) in the fluoroperovskites ABF(3) (A=K and Cs; B=Zn, Mg, Cd and Ca) are theoretically investigated from the perturbation formulas of these parameters for a 3d(5) ion under ideal octahedra. In the above treatments, not only the crystal-field mechanism but also the charge transfer mechanism is considered uniformly on the basis of the cluster approach. The theoretical EPR parameters are in good agreement with the experimental data.

Studies on the defect structure for Cu2+ in CdSe nanocrystals.

The defect structure for Cu(2+) in CdSe nanocrystals is theoretically studied by analyzing the spin Hamiltonian parameters of this impurity center. This center is ascribed to Cu(2+) occupying the octahedral interstitial site, rather than the tetrahedral substitutional Cd(2+) site proposed by previous work. The Cu(2+) center exhibits slight tetragonal elongation distortion (characterized by the elongation parameter rho approximately 0.

Investigations of the local structures and spin Hamiltonian parameters for the trigonal Rh4+ and Ir4+ centers in rhombohedral BaTiO3.

The local structures and spin Hamiltonian parameters (g factors and the hyperfine structure constants) of the Rh(4+)(4d(5)) and Ir(4+)(5d(5)) centers in rhombohedral BaTiO(3) are theoretically investigated from the formulas of these parameters for a nd(5) (n=4 and 5) ion with low spin (S=1/2) in a trigonally distorted octahedron. From the calculations, the impurity ions are found not to occupy exactly the host Ti(4+) site in BaTiO(3) but to suffer a slight inward shift ( approximately 0.13A) towards the center of the oxygen octahedron along the C(3) axis, yielding much smaller trigonal distortion as compared with that of the host Ti(4+) site.

Investigations on the local angular distortions and the spin-Hamiltonian parameters for Ni+ in sulfides.

The local angular distortions and the spin-Hamiltonian parameters (the g factors and the hyperfine parameters) for Ni(+) in ABS(2) (A=Cu, Ag; B=Al, Ga) ternary sulfides are theoretically investigated from the perturbation formulas of these parameters for 3d(9) ions in a tetragonally distorted tetrahedron. In view of the strong covalency of such systems, the ligand orbital and spin-orbit coupling contributions are taken into account using the cluster approach. The local impurity-ligand bond angles in the Ni(+) centers are found to be about 1.

Studies on the spin Hamiltonian parameters of vitamin B12r.

The spin Hamiltonian parameters g factors g(i) (i=x, y, z) and the hyperfine structure constants A(i) of vitamin B(12r) have been theoretically studied from the perturbation formulas of these parameters for a Co(2+)(3d(7)) ion with low spin (S=1/2) in rhombically distorted octahedra. The related crystal-field parameters are determined from the point-charge-dipole model and the local structure around Co(2+) in vitamin B(12r). The theoretical spin Hamiltonian parameters are in good agreement with the experimental data.

Studies of the spin Hamiltonian parameters and local structure for ZnO:Cu2+.

The spin Hamiltonian parameters (the g factors and the hyperfine structure constants) and local structure for ZnO:Cu2+ are theoretically studied from the perturbation formulas of these parameters for a 3d9 ion under trigonally distorted tetrahedra. The ligand orbital and spin-orbit coupling contributions are taken into account from the cluster approach due to the significant covalency of the [CuO4](6-) cluster. According to the investigations, the impurity Cu2+ is suggested not to locate on the ideal Zn2+ site in ZnO but to undergo a slight outward displacement (approximately 0.

Theoretical investigation of the EPR parameters and local structure for trigonal Yb3+ ion in Bi4Ge3O12 crystal.

Bi4Ge3O12 single crystals are of great interest for science research and engineering applications. In this paper, the electron paramagnetic resonance (EPR) g factors g||, gperpendicular of Yb3+ and hyperfine structure constants A||, Aperpendicular of 171Yb3+ and 173Yb3+ isotopes in Bi4Ge3O12 crystal are calculated from the perturbation formulas of these parameters. The crystal-field parameters are obtained from the superposition model and the crystal structure data.

Investigations on the defect structures and the g factors for the two orthorhombic Ti3+ centers in CaYAlO4.

The defect structures and the g factors for the two orthorhombic Ti(3+) centers (A and B) in CaYAlO(4) are theoretically investigated from the perturbation formulas of the g factors g(xi), g(eta) and g(xi) for a 3d(1) ion in orthorhombically distorted octahedra. The centers may be attributed to Ti(3+) locating on the Al(3+) site associated with one nearest-neighbouring oxygen vacancy (V(O)) along the z (or c) axis and additional next-nearest-neighbouring Ti(4+) replacing the host Al(3+) (Ti(Al), i.e.

Theoretical studies of the spin Hamiltonian parameters and local structures for Cs3CoX5 (X = Cl, Br).

The spin Hamiltonian (SH) parameters (zero-field splitting D and anisotropic g factors g(||) and g( perpendicular)) and local structures for Cs(3)CoX(5) (X = Cl, Br) are theoretically studied from the perturbation formulas of the SH parameters for a 3d(7) ion in tetragonally distorted tetrahedra based on the cluster approach. In these formulas, both the contributions from the crystal-field (CF) mechanism and those from the charge-transfer (CT) mechanism are taken into account. It is found that the [CoX(4)](2-) clusters are slightly elongated and the tetragonal distortion angles Deltatheta(=theta-theta(0), where theta(0) equals to approximately 54.

Theoretical studies of lattice distortions around the impurity ions in V2+ doped CdCl2, CdI2 and PbI2.

The lattice distortions around the impurity ions in V(2+) doped CdCl(2), CdI(2) and PbI(2) are theoretically studied from the perturbation formulas of the spin Hamiltonian (SH) parameters zero-field splitting, g factors and the hyperfine structure constants for a 3d(3) ion in trigonal symmetry based on the cluster approach. In these formulas, the contributions from the s-orbitals of the ligands are taken into account. Based on the studies, it is found that the local angles beta (between the impurity-ligand bonding lengths and the C(3) axis) in the impurity centers are smaller than the angles beta(H) in the hosts.