A computational study of AlN nanotube as an oxygen detector

Interaction of O2 molecule and a zigzag aluminum nitride nanotube(AlNNT) was studied based on the density functional theory.The O2 molecule is adsorbed on the surface of AlNNT with the adsorption energies in the range of 11.0 to 12.1 kJ/mol.Geometrical structure of the AlNNT remains intact in the presence of oxygen molecule while its electronic structure dramatically changes so that its HOMO(or SOMO)-LUMO gap is approximately reduced to half of its original value.It suggests that the AlNNT may be used as a gas sensor for the O2 detection.     

Inhomogeneous charge transfer within monolayer zinc phthalocyanine absorbed on TiO2(110)

The d-orbital contribution from the transition metal centers of phthalocyanine brings difficulties to understand the role of the organic ligands and their molecular frontier orbitals when it adsorbs on oxide surfaces. Here we use zinc phthalocyanine (ZnPc)/TiO(2)(110) as a model system where the zinc d-orbitals are located deep below the organic orbitals leaving room for a detailed study of the interaction between the organic ligand and the substrate. A charge depletion from the highest occupied molecular orbital is observed, and a consequent shift of N1s and C1s to higher binding energy in photoelectron spectroscopy (PES). A detailed comparison of peak shifts in PES and near-edge X-ray absorption fine structure spectroscopy illustrates a slightly uneven charge distribution within the molecular plane and an inhomogeneous charge transfer screening between the center and periphery of the organic ligand: faster in the periphery and slower at the center, which is different from other metal phthalocyanine, e.g., FePc/TiO(2). Our results indicate that the metal center can substantially influence the electronic properties of the organic ligand at the interface by introducing an additional charge transfer channel to the inner molecular part.     

The dimerization study of some cationic monomethine cyanine dyes by chemometrics method

The thermodynamics of the monomer-dimer equilibrium of five cationic monomethine cyanine dyes has been studied by means of UV-vis spectroscopy and advanced chemometrics methods. The dimerization constants were determined by studying the dependence of their absorption spectra on temperature in the range 20?C75°C and were found to be: 1.91 × 10³, 1.53 × 10³, 6.81 × 10³, 5.18 × 10³, and 8.28 × 10³ dm³ mol^?1 for 1, 2, 3, 4, and 5 respectively. The absorption spectra of the monomer and dimer forms of the dyes were also determined, as well as the enthalpy and entropy of the dimerization.     

An XML format for benchmarks in High School Timetabling

The High School Timetabling Problem is amongst the most widely used timetabling problems. This problem has varying structures in different high schools even within the same country or educational system. Due to lack of standard benchmarks and data formats this problem has been studied less than other timetabling problems in the literature. In this paper we describe the High School Timetabling Problem in several countries in order to find a common set of constraints and objectives. Our main goal is to provide exchangeable benchmarks for this problem. To achieve this we propose a standard data format suitable for different countries and educational systems, defined by an XML schema. The schema and datasets are available online.     

Self-Reciprocal Irreducible Pentanomials Over \mathbb{F}_2

Joseph Yucas and Gary Mullen conjectured that there is no self-reciprocal irreducible pentanomial of degree n over if n is divisible by 6. In this note we prove this conjecture for the case n ≡ 0, and disprove the conjecture for the case n ≡ 6 (mod 12) AMS Classifications: 11T55     

Some characterization and ordering results based on entropies of current records

The aim of this paper is to investigate the entropy properties of current records. Several characterizations are obtained based on the entropy of these statistics. It is proved that the equality of the entropy of the endpoints of record coverage is a characteristic property of symmetric distribution. It is shown that the parent distribution can be identified uniquely by the entropy properties of the endpoints of record coverage. Considering the records coming from distribution with decreasing (increasing) density, the monotonicity of entropy of current records is discussed. We also prove that the dispersive ordering of the parent distributions implies the entropy ordering of their respective current records.     

Analysis of strained double-lightly doped MOSCNT using NEGF

The effects of uniaxial and torsional strains on the double-lightly doped MOSCNT (DLD-MOSCNT) performances are investigated, using the non-equilibrium Green function (NEGF) formalism in mode space approach. The Hamiltonian of the device is obtained by a tight-binding approximation assuming that only p _z orbitals are contributing in carrier transport. In all simulation processes, one mode with the lowest subband is considered. DLD-MOSCNT has a small band-to-band tunneling and almost eliminates the ambipolar behavior of I _DS–V _GS characteristics because of the band engineering. We use a modified model to demonstrate the strain effects on such a low OFF-current device. The results show that the strain effects mainly depend on the chiral vector and diameter of CNT. The strain causes band gap and carrier velocity changes, which result in variation of ON- or OFF-current. In addition, the subthreshold swing of this device under uniaxial strain is calculated, which is about 61 mV/Dec for 2 % tensile strain in (16,0) and for ?2 % compressive strain in (17,0). Under the uniaxial strain, in the case that the energy band gap increases, the variation of DIBL is very small.     

Mucin-Inspired Single-Chain Polymer (MIP) Fibers as Potent SARS-CoV-2 Inhibitors

Mucins are the key component of the defensive mucus barrier. They are extended fibers of very high molecular weight with diverse biological functions depending strongly on their specific structural parameters. Here, we present a mucin-inspired nanostructure, produced via a synthetic methodology to prepare methacrylate-based dendronized polysulfates ( MIP-1 ) on a multi gram-scale with high molecular weight (MW=450 kDa) and thiol end-functionalized mucin-inspired polymer ( MIP ) via RAFT polymerization. Cryo-electron tomography (Cryo-ET) analysis of MIP-1 confirmed a mucin-mimetic wormlike single-chain fiber structure (length=144±59 nm) in aqueous solution. This biocompatible fiber showed promising activity against SARS-CoV-2 and its mutant strain, with a remarkable low half maximal (IC₅₀) inhibitory concentration (IC₅₀=10.0 nM). Additionally, we investigate the impact of fiber length on SARS-CoV-2 inhibition by testing other functional polymers ( MIPs ) of varying fiber lengths.