We have performed polarized Raman scattering measurements on WTe$_2$, for which an extremely large positive magnetoresistance has been reported recently. observe 5 A$_1$ phonon modes and 2 A$_2$ out of 33 active modes, with frequencies in good accordance first-principles calculations. The angular dependence the intensity peaks observed is consistent tensors $C_{2v}$ point group symmetry attributed to WTe$_2$. Although spectra suggest neither strong electron-phonon nor spin-phonon coupling,...

Ni-Based catalysts using mixed oxides of Al2O3–SiO2, Al2O3–TiO2, TiO2–SiO2, and TiO2–ZrO2 as supports were evaluated for hydrotreatments guaiacol the model compound characterized by N2 physical adsorption, X-ray diffraction (XRD), temperature-programmed desorption ammonia (NH3-TPD), reduction hydrogen (H2-TPR) techniques. The influence support, solvent, reaction temperature, pressure on conversion product distributions determined. Guaiacol 100% with cyclohexane selectivity 86.4% was obtained...

WTe${}_{2}$ has recently been reported to exhibit extremely large magnetoresistance, which may find potential applications in devices such as highly sensitive magnetic sensors and hard drives. In this paper, using ultrafast optical spectroscopy, the authors track relaxation of photoexcited carriers time domain they return equilibrium WTe${}_{2}$. Their experimental results not only resolve scales that ultimately limit material electronic devices, e.g., high-speed drives, but also shed new...

We report studies on several methylated uracils and thymines thymine−water complexes in the gas phase using resonantly enhanced multiphoton ionization (REMPI) laser-induced fluorescence (LIF) spectroscopy. Results from two different REMPI experiments provided strong evidence that, after photoexcitation to S1 state, bare molecules were funneled into trapped a dark state via fast internal conversion. Lifetimes of this determined be tens hundreds nanoseconds, depending energy degree methyl...

We report observations of a dark state in the decay pathways thymine, 1,3-dimethyl uracil, and 1-methyl uracil gas phase. After initial excitation by nanosecond laser, excited molecules failed to return ground but rather were trapped for tens hundreds nanoseconds. This result contradicts those reported water solutions. therefore propose that photochemistry these pyrimidine bases is different phase from liquid effectively quenched Although we do not have quantitative measure yield this state,...

The new nonlinear optical crystal YxLayScz(BO3)4 (x + y z = 4) has been discovered. Phase boundaries have established in the determination of x, y, composition parameters that define existence region trigonal huntite-type structure. From single-crystal X-ray diffraction measurements, member Y0.57La0.72Sc2.71(BO3)4 found to crystallize space group R32 with cell dimensions a 9.774(1) and c 7.944(3) Å. Large single crystals grown by high-temperature solution method. high-energy absorption edge...

The aggregation of ride-sharing platforms has forced traditional to decide whether join or leave these emerging platforms. This study presents a stylized model analyzing the demand, supply, and profit two self-operated platforms, C2C (such as DiDi Uber) B2C considering platform awareness commissions. investigates conditions under which should employ entry strategy based on optimization method Cournot game theory, well exploring reasons why choose withdraw after joining. results show that in...

The issues with social media landscape are proliferation of disinformation, misinformation, and misinformation. widespread deepfakes makes is harder to distinguish between authentic content fabricated content. mediating effect literacy on news credibility has been understudied in previous research; the objective study investigate how much literacy, skepticism fear missing out (FOMO) influencing users' trust disseminated platforms. To achieve this, a survey was conducted assess towards news,...

The rotationally resolved photoelectron spectrum of high vibrational levels O 2 + in the Franck–Condon gap was investigated using pulsed field ionization, zero kinetic energy spectroscopy. By a coherent extreme ultraviolet light source for single-photon excitation, ν = 6–24 X Π g were studied. This is first time higher than 14 have been observed with rotational resolution. highest level studied present work had corresponding to 70% well depth. Along novelty spectroscopic technique, results...

Experimental measurements and theoretical calculations of brute force orientation in pyridazine (1,2-diazine) are discussed. The sample was prepared using supersonic expansion, attempted via a strong uniform electric field. electrostatic interaction between the permanent dipole moment field sufficient to orient align molecular axes. Resonantly enhanced multiphoton ionization through π* ← n transition used characterize alignment is perpendicular moment. As molecules became aligned field,...

Calculations of orientation effects polar molecules in a uniform electric field are presented for the most general scenario, an asymmetric top molecule with permanent dipole not parallel to principal axis. In addition details calculation procedure, including matrix elements Hamiltonian, three different treatments population distribution Stark levels discussed. The adiabatic approach assumes noncrossing rule all energy as increases, nonadiabatic searches level similar wave function under...

We report pulsed field ionization spectra of an ionic electronically excited state, specifically, the NO+(a 3Σ+ v+=0,1,2)←NO(X 2Π1/2) transition. A coherent vacuum ultraviolet light source provides single photon excitation, which enables a direct measurement potentials for three vibrational levels — I.P.(v+=0)=126 392±1.5 cm−1, I.P.(v+=1)=127 653±1.5 and I.P.(v+=2)=128 884±1.5 cm−1. The rotational structure these has been simulated using standard model line strengths in photoelectron...

Single-photon zero-kinetic-energy pulsed-field-ionization spectra have been measured for the v+=0 and 1 levels of CO+ (X 2Σ+) level N2+ 2Σg+) by coherent XUV radiation. In spite similarities in electronic structure CO N2, ion show dramatically different intensities Q branches. These threshold are interpreted on basis ab initio calculations rotational distributions. Agreement between calculated is very encouraging. Improved values ionization potentials (113 025.6 115 211.2±1.5 cm−1 1,...

Far infrared (FIR) spectroscopy of polycyclic aromatic hydrocarbons is particular interest to astrophysics since vibrational modes in this range are representative the molecular size and shape. This information hence important for identification chemical compositions modeling IR spectrum observed outer space. In work, we report neutral cation FIR tetracene vaporized from a laser desorption source. Results two-color resonantly enhanced multiphoton ionization zero kinetic energy photoelectron...

We report zero kinetic energy photoelectron (ZEKE) spectroscopy of pyrene via resonantly enhanced multiphoton ionization. Our analysis centers on the symmetry first electronically excited state (S1), its vibrational modes, and vibration ground cationic (D0). From comparisons between observed frequencies those from ab initio calculations at configuration interaction singles level using 6-311G (d,p) basis set, based other previous experimental theoretical reports, we confirm 1B2u for S1 state....

We demonstrate the practicality of electron diffraction single molecules inside superfluid helium droplets using CBr4 as a testing case. By reducing background from pure undoped via multiple doping, with small corrections for dimers and trimers, clearly resolved rings similar to those gas phase can be observed. The experimental data doped are in agreement both theoretical calculations results gaseous species. abundance monomers clusters droplet beam also qualitatively agrees Poisson...

Orientation of pyrimidine in a strong electric field was measured using resonantly enhanced multiphoton ionization (REMPI) and laser induced fluorescence (LIF). The ion yields showed preference for perpendicular excitation relative to the orientation field, implying relationship between permanent dipole transition dipole. Calculation results linear variation method reproduced observed spectral features, overall intensity, polarization laser. S1 state thereby determined be +0.6 Debye....

We report doping of green fluorescent protein from an electrospray ionization (ESI) source into superfluid helium droplets. From analyses the time profiles doped droplets, we identify two distinct groups The faster group has a smaller average size, on order 10

We present an experimental investigation of the effect kinetic energy on ion doping efficiency superfluid helium droplets using cesium cations from a thermionic emission source. The Cs+ is controlled by bias voltage collection grid collinearly arranged with droplet beam. Efficient ions energies 20 eV up to 480 V has been observed in different sized droplets. relative determined both and average size At fixed source temperature, number doped increases increasing voltage, while decreases. This...

Abstract We present evidence of halogen bond in iodine clusters formed superfluid helium droplets based on results from electron diffraction. Iodine crystals are known to form layered structures with intralayer bonds, interatomic distances shorter than the sum van der Waals radii two neighboring atoms. The diffraction profile dimer dominated embedded reveals an distance 3.65 Å, much closer value 3.5 Å 4.3 Å. larger deviates a single layer structure; instead, bi‐layer structure qualitatively...