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Abstract: Based on the extended Huygens–Fresnel principle and second-order moments of the Wigner distribution function (WDF), the analytical formulation for the average intensity, the root-mean-square (rms) beam width and M 2-factor of partially coherent higher-order cosh-Gaussian (ChG) beams propagating in non-Kolmogorov turbulence are derived. The influences of the beam parameters and the spectrum parameters associated with the non-Kolmogorov turbulence on the propagation properties of partially coherent higher-order ChG beams in non-Kolmogorov turbulence are numerically investigated. Numerical results reveal that partially coherent higher-order ChG beams with higher beam order, larger decentered parameter and smaller coherence length are less affected by the turbulence. Furthermore, it is found that the beams will be more affected by the turbulence with smaller inner scale, larger outer scale or larger structure constant. In addition, numerical results reveal that the propagation properties of beams in non-Kolmogorov turbulence are largely dependent on the generalized exponent α, the structure constant, the inner and outer scale, which is much different from that in the case of Kolmogorov turbulence. This research may be useful for the practical applications of partially coherent higher-order ChG beams in connection with optical communications and the remote sensing. [Copyright &y& Elsevier]

Abstract: A general analytical expression for the calculation of the two-dimensional four-mode Franck–Condon overlap integrals was presented and applied to scrutinize the photoelectron spectroscopy of . Geometry optimization and harmonic vibrational frequency calculations have been performed on the 2B1 state of ClO2 and 1A1 state of by using the density functional theory (B2PLYP functional) and the coupled cluster singles and doubles with perturbative triples [CCSD(T)] methods with various basis sets up to aug-cc-pVQZ. The adiabatic electron affinity of ClO2 was computed by using the CCSD(T) method extrapolated to the complete basis set limit with aug-cc-pVXZ (X=D, T, Q). Franck–Condon analyses and spectral simulation were carried out on the ClO2( 2B1)–( 1A1) photodetachment process. The simulated photoelectron spectrum of are in accord with the experiment. While the Duschinsky effect plays a minor role and can be neglected. In addition, the equilibrium geometry parameters, R(Cl–O)=1.572±0.005Å and (O–Cl–O)=112.5±0.5°, of the 1A1 state of , are obtained by employing an iterative Franck–Condon analysis procedure in the spectral simulations. [ABSTRACT FROM AUTHOR]

Abstract: To study the propagation properties of partially coherent Laguerre–Gaussian (PLG) beams through turbulent atmosphere, the analytical formulas are derived for the angular width and the beam-propagation factor (M 2-factor) of PLG beams by using the extended Huygens–Fresnel principle and the second-order moments of the Wigner distribution function (WDF). The corresponding numerical results are also calculated. When propagation distance increases, the angular width is found to spread faster for PLG beams with higher beam order, smaller correlation length and bigger structure constant The angular width of PLG beams decreases with increase in waist width (w 0).The M 2-factor of PLG beams with higher beam order and smaller correlation length is less affected by turbulence with increase in propagation distance. The propagation properties of the M 2-factor for PLG beams with the smaller structure constant are better than that with bigger structure constant . The M 2-factor of PLG beams decreases with increase in the wavelength λ, and it is also less affected by turbulence for beams with higher order and smaller correlation length. Furthermore, for the PLG beams with the same beam order, the angular width and the M 2-factor keep invariable in free space. [ABSTRACT FROM AUTHOR]

Based on the real physical model and operating environment of the spacecraft tank, the numerical model of the tank is established and the sloshing behavior of liquid hydrogen in the tank under different longitudinal excitations is studied in this work. The Realizable k- ε model is used to predict the fluid turbulence, and the mixture model is used to analyze the phase transitions and flows. The harmonic external excitation is loaded by the user-defined function (UDF). Based on the CFD sloshing model verified through comparison with experimental results, the influences of different longitudinal external excitation frequencies and amplitudes on the liquid hydrogen volume fraction in the tank are firstly analyzed. On this basis, including pressure and other physical quantities of the monitoring points and whole internal fluid domain during the sloshing simulation process are studied quantitatively. In addition, the relationship between the carrier amplitude of the sloshing curves and the external excitation amplitude is discussed. The simulation results show that in microgravity environment, compared with large amplitude excitation, high-frequency longitudinal harmonic excitation has a significant effect on the variation of physical parameters in the tank, which may become a negative factor for the safety of liquid hydrogen storage and supply systems. Meanwhile, the traditional baffle design has a limited influence on the liquid hydrogen motion under the high-frequency longitudinal excitation which may occur during the spacecraft changing load process. The results provide valuable information for the understanding of sloshing behavior and safety evaluation of the tank under longitudinal excitation. • Longitudinal harmonic excitations are applied to a LH 2 tank in microgravity. • Excitation frequencies over 20 Hz significantly effect on the sloshing behavior. • The shape of the gas-liquid interface is insensitive to the excitation amplitude. • Baffles limit sloshing better at high amplitude excitations than at high frequency. [ABSTRACT FROM AUTHOR]

Abstract: Based on the extended Huygens–Fresnel principle and the unified theory of coherence and polarization, the analytical expressions for the elements of the cross-spectral density matrix, the degree of polarization and the degree of coherence of partially coherent elegant Laguerre–Gaussian (PCELG) beams in non-Kolmogorov turbulence have been derived. An investigation of the changes in the on-axis spectral degree of polarization (SDP) and in the spectral degree of coherence (SDC) of PCELG beams for different beam parameters and turbulence parameters propagating in non-Kolmogorov turbulence are specifically illustrated by numerical examples. [Copyright &y& Elsevier]

Abstract: A program developed to calculate multidimensional Franck–Condon factors including Duschinsky effects is described and used to simulate the vibrationally resolved photoelectron spectra of S2O− combining with ab initio molecular orbital calculations. Geometry optimizations and harmonic vibrational frequency calculations have been performed on the state of S2O and state of S2O−. Franck–Condon analysis and spectral simulations were carried out on the first photoelectron band of S2O−. The simulated spectra obtained by using B3LYP/6-311+G(3df) are in excellent agreement with the experiment. In addition, the accurate equilibrium geometric parameters, r(ss)=0.1996±0.0005nm and r(so)=0.1514±0.0005nm, of the state of S2O−, are deduced by employing an iterative Franck–Condon analysis procedure in the spectral simulation. Furthermore, the well-resolved theoretical spectrum is derived by improving the resolution of photoelectron spectra in simulations. [Copyright &y& Elsevier]

Highlights • Adiabatic excitation energy, IP and vibrational frequencies of m-BrFPh in S 1 and D 0 states were accurately measured and assigned. • Franck-Condon simulations are performed to aid us in confidently assigning major vibrational modes in S 1 and D 0 states. • The mixing of vibrational modes both between S 0 & S 1 and between S 1 & D 0 has been discussed. Abstract Vibrations of m-bromofluorobenzene (m-BrFPh) in the first excited state (S 1) and the cationic ground state (D 0) are investigated by resonance-enhanced multiphoton ionization (REMPI) spectroscopy and slow electron velocity-map imaging (SEVI) spectroscopy, respectively. Quantum chemical calculations have been adopted to assign the observed vibrational bands, as well. The band origin of the S 1 ← S 0 electronic transition defines the adiabatic excitation energy to be 36,987 ± 4 cm−1 based on the resonance-enhanced one-color two-photon ionization spectrum of m-BrFPh. And adiabatic ionization potential (IP) of 73,903 ± 8 cm−1 is determined from band origin in the SEVI spectra. Meanwhile, the computed frequencies are in excellent agreement with the experimental observations and Franck-Condon simulations are performed to aid us to confidently assign major vibrational modes in S 1 and D 0 states. And the changes in the wavenumber of the vibrational modes upon S 1 ← S 0 and D 0 ← S 1 transitions are examined. Furthermore, the mixing of vibrational modes both between S 0 & S 1 and between S 1 & D 0 has been discussed. Graphical abstract Image, graphical abstract [ABSTRACT FROM AUTHOR]

Background irradiated electrons in photoelectron spectra are known to take place under the ultraviolet light irradiation. Therefore, it deserves discussing the reduction of such electrons in the electron spectra in this work. The main problem present in these electron spectra will largely be overcome through a workflow and process, namely, a combination method of rotating images with angular-tailored and subtracting noise electrons of images which gives rise to non-noise electron peaks. An improved SNR is readily obtained for REMPI-SEVI spectra of 3-bromofluorobenzene (3-Br-FPh) compared with no noise–subtracted and no-angular-tailored spectra. More details are given including electron velocity-map imaging analysis on S − , CuOH − (H 2 O), and 3-Br-FPh in the following sections. [ABSTRACT FROM AUTHOR]

Abstract: Geometry optimization and harmonic vibrational frequency calculations were performed on the states of CH3OO/CD3OO and states of CH3OO−/CD3OO− at the B3LYP, QCISD and CCSD levels. The electron affinity energies of CH3OO/CD3OO were calculated at various theory levels. Franck–Condon analyses and spectral simulations were carried out on the photodetachment processes. The spectral simulations of vibrational structures based on the computed Franck–Condon factors are in agreement with the observed spectra. [Copyright &y& Elsevier]

Abstract: Geometry optimization and harmonic vibrational frequency calculations were performed on the and states of HOO and state of HOO−. The electron affinity and the term energy () of HOO were calculated at various theory levels. Franck–Condon analyses and spectral simulations were carried out on the and photodetachment processes. The spectral simulations of vibrational structures based on the computed Franck–Condon factors are in excellent agreement with the observed spectra. In addition, the equilibrium geometrical parameters of the state of HOO− and state of HOO were obtained in the spectral simulations. [Copyright &y& Elsevier]

Abstract: Two premixed laminar pyrrole/oxygen/argon flames at 3.33 kPa (25 Torr) with equivalence ratios of 0.55 (C/O/N = 1:5.19:0.25) and 1.84 (C/O/N = 1:1.56:0.25) have been investigated using tunable synchrotron photoionization and molecular-beam mass spectrometry techniques. All observed flame species, including some nitrogen-containing intermediates, have been identified by measurements of photoionization efficiency spectra. Mole fraction profiles of species including reactants, intermediates, and products have been determined by scanning burner position at some selected photon energies near ionization thresholds, and flame temperature has been measured by a Pt/Pt–13% Rh thermocouple. The results indicate that N2, NO, and NO2 are the major nitrogenous products, while hydrogen cyanide, isocyanic acid, and 2-propenenitrile are the most important nitrogen-containing intermediates in pyrrole flames. Radicals such as methyl, propargyl, allyl, cyanomethyl, n-propyl, isobutyl, cyclopentadienyl, phenyl, cyclohexyl, phenoxy, and 4-methylbenzyl are observed as well. Moreover, ethenol and methylacrylonitrile are also detected. Reaction pathways involving the major species are proposed. The new results will be useful in developing a kinetic model of nitrogenous compound combustion. [Copyright &y& Elsevier]

Abstract: The interaction potential of van der Waals He–BH (X1Σ) complex has been firstly studied by ab initio calculations using single and double excitation coupled cluster with perturbative triples correction CCSD(T) method. The full counterpoise method is applied to correct for the basis set superposition error. With the basis set of the aug-cc-pV5Z augmented with 33211 midbond functions, the CP-corrected interaction energies are determined for 216 configurations. The values are further fitted to a two-dimensional potential model by a two-step least squares procedure. Two minima are found on the potential energy surface. The global minimum corresponds to a skew T-shaped geometry with energy −34.4389cm−1 at R =6.04a 0 and θ =70.0°. The shallower minimum locates at R =8.35a 0 and θ =180° with well depth −8.5511cm−1. A saddle point with energy −7.80cm−1 appears at R =8.20a 0 and θ =132.0°. [Copyright &y& Elsevier]

[Display omitted] • Polydopamine-crosslinked polyelectrolyte multilayer films are designed. • Multilayers are fabricated by the simple and versatile layer-by-layer assembly. • Photothermal effect induced by NIR light gradually varies with number of bilayers. • Perfect healing capability is promoted by photothermal effect. The development of a versatile and efficient thick membrane is significant to realize the practical applications of a membrane material, but could be limited by its preparation method. In this work, a facial method to fabricate mussel-inspired and polydopamine-crosslinked polyelectrolyte multilayers with fast growing and excellent healing capabilities using layer-by-layer (LbL) assembly is demonstrated. Two kinds of polyelectrolytes, poly(acrylic acid) (PAA) and branched polyethylenimine (PEI), are used as building blocks. By simply preblending dopamine (DA) with PAA component (PAA&DA, pH 2.5) and then subsequently assembling with PEI (pH 8.5), the assembled (PAA&DA/PEI)*n multilayer films based on supramolecular interactions and covalent bonds exhibits an exponential growth behavior, leading to a rapid increment in film thickness. The formed polydomamine in the multilayers by crosslinking amine groups in PEI and catechol moieties in DA under an alkaline condition during LbL assembly process endows multilayer films excellent healing capability triggered by NIR light. The assembled (PAA&DA/PEI)*n multilayers are very stable. There are no any ruptures in the multilayer films even after exposing under NIR light for up to 10 min. [ABSTRACT FROM AUTHOR]