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The present work aims to focus on the synthesis and spectral studies of the charge-transfer interaction between the nitro organic acceptors molecules [e.g., 2,4,6-trinitrophenol (PA), 4-nitrophenol (4-NP), 4-nitroacetophenone (4-NAP), and m-dinitrobenzene (m-DNB)] with triamterene (TM) drug donors, which have many applications in industry, biology, and chemistry. The CT complexes of PA and 4-NP are formed by the association of electrondeficient and electron-rich moieties, held together by the weak force of attraction through a hydrogen bond. These molecules have been explored through the FTIR and Raman spectroscopic techniques. The speculated 1:1 or 1:2 structures of the complexes [(TM)(PA)], [(TM)(4-NP)2], [(TM)(4-NAP)2], and [(TM)(m-DNB)2] determined by microanalytical and theoretical analyses shows that the interaction occurs through a H2N+–H···O−(O----H) (O–H----NH2) bond or by n–π* regarding 4-NAP and m-DNB complexes. The thermogravimetric technique was utilized to determine the thermostability of the synthesized charge-transfer complexes by making comparisons to their constituents. The computational study has been carried out on the studied molecule, which has the most stable conformer using density functional theory (DFT). A comparative study of electronic and vibrational spectroscopy has been done with that of experimental results. The experimentally obtained structure was compared with an optimized structure for various parameters, such as bond length, bond angles, oscillator strength, dipole moment, and molecular electrostatic potential is predicted theoretically. The energy band gap from HOMO-to-LUMO was theoretically estimated using (B3LYP/6-311++G(d,p) level) from frontier molecular orbital energies, and the outcome data are employed to characterize the chemical structures of the synthesized complexes based on molecular properties. [ABSTRACT FROM AUTHOR]

The energy levels, transition energies, transition probabilities, weighted oscillator strengths, and line strengths of Li-like ions (Z = 7–11) in dense plasmas are investigated in this work. The relativistic effects and electron correlation effects are described by the MCDHF method. The ion sphere model is applied to include the dense plasma screening effect. The ground configuration 1s22s and the excited 1s22p, 1s23l (l = 0–2) are considered. The configuration sets are enlarged until n = 7 where the calculated energy levels have converged. The critical free electron densities of 1s23d states are estimated. Except for 1s23s–1s23p transitions, the transition energies for Δ n = 0 increase, and for Δ n ≠ 0 decrease with increasing free electron densities. For 1s23s–1s23p transitions, the spectra show blue-shift at lower free electron densities and red-shift at higher free electron densities, and the energy level crossing phenomens are observed at higher free electron densities. [ABSTRACT FROM AUTHOR]

The amplitude-dependent frequency of the oscillations, termed nonisochronicity, is one of the essential characteristics of nonlinear oscillators. In this paper, the dynamics of the Rössler oscillator in the presence of nonisochronicity is examined. In particular, we explore the appearance of a new fixed point and the emergence of a coexisting limit-cycle and quasiperiodic attractors. We also describe the sequence of bifurcations leading to synchronized, desynchronized attractors and oscillation death states in the coupled Rössler oscillators as a function of the strength of nonisochronicity and coupling parameters. Furthermore, we characterize the multistability of the coexisting attractors by plotting the basins of attraction. Our results open up the possibilities of understanding the emergence of coexisting attractors and into a qualitative change of the collective states in coupled nonlinear oscillators in the presence of nonisochronicity. [ABSTRACT FROM AUTHOR]

Effects of magnetic field on the excitonic properties, optical absorption and the changes of refractive index are studied numerically in a CdS/CdSe/CdS asymmetric quantum well with the solution of one dimensional Schrödinger wave equation using Aldrich-Bajaj effective potential. The magnetic field dependence on the binding energy, optical transition energy and the oscillator strength of a bound polaron is investigated taking into account the geometrical confinement effect. The envelop wave function is employed for obtaining the eigen energies using variational technique within the effective mass approximation. The density matrix method associated with the numerical calculations of the trail wave function is engaged to obtain the optical properties with the two level system. The numerical results show that the excitonic and optical properties can be altered with the change in well widths, barrier width and the application of magnetic field strength. It also exhibits that the peaks of absorption coefficients and changes of refractive index increase with the magnetic field strength and move towards the higher photon energies. [ABSTRACT FROM AUTHOR]

In this comment, through our independent calculations, we assess that the recently reported results of El-Maaref et al. [Indian J. Phys.91 1029 (2017)] for energy levels, oscillator strengths, radiative rates, and lifetimes are inaccurate and unreliable for several levels and transitions of S-like Sc VI. [ABSTRACT FROM AUTHOR]

Accurate atomic data are essential for opacity calculations and for abundance analyses of the Sun and other stars. The aim of this work is to provide accurate and extensive results of energy levels and transition data for C  i – iv. The Multiconfiguration Dirac–Hartree–Fock and relativistic configuration interaction methods were used in this work. To improve the quality of the wavefunctions and reduce the relative differences between length and velocity forms for transition data involving high Rydberg states, alternative computational strategies were employed by imposing restrictions on the electron substitutions when constructing the orbital basis for each atom and ion. Transition data, for example, weighted oscillator strengths and transition probabilities, are given for radiative electric dipole (E1) transitions involving levels up to 1s22s22p6s for C  i , up to 1s22s27f for C  ii , up to 1s22s7f for C  iii , and up to 1s28g for C  iv. Using the difference between the transition rates in length and velocity gauges as an internal validation, the average uncertainties of all presented E1 transitions are estimated to be 8.05 per cent, 7.20 per cent, 1.77 per cent, and 0.28 per cent, respectively, for C  i – iv. Extensive comparisons with available experimental and theoretical results are performed and good agreement is observed for most of the transitions. In addition, the C  i data were employed in a re-analysis of the solar carbon abundance. The new transition data give a line-by-line dispersion similar to the one obtained when using transition data that are typically used in stellar spectroscopic applications today. [ABSTRACT FROM AUTHOR]

A luminescent bimetallic AuI complex comprised of N‐heterocyclic carbene (NHC) and carbazole (Cz) ligands, that is, (NHC')Au(NHC)AuCz has been synthesized and studied. Both carbene ligands in the bimetallic complex act as electron acceptors in tandem to increase the energy separation between the ground and excited state, which is higher than those found in either monometallic analogue, (NHC)AuCz and (NHC')AuCz. A coplanar geometry designed into the tandem complex ensures sufficient electronic coupling between the π‐orbitals of the ligands to impart a strong oscillator strength to the singlet intra‐ligand charge‐transfer (1ICT) transition. Theoretical modelling indicates that the emissive ICT excited state involves both NHC ligands. The tandem complex gives blue luminescence (λmax=480 nm) with a high photoluminescent quantum yield (ΦPL=0.80) with a short decay lifetime (τ=0.52 μs). Temperature‐dependent photophysical studies indicate that emission is via thermally assisted delayed fluorescence (TADF) and give a small singlet‐triplet energy difference (ΔEST=50 meV, 400 cm−1) consistent with the short TADF lifetime. [ABSTRACT FROM AUTHOR]

Summary: In this study, the average diameter of the grown CNTs on Ni–Cu NPs @ a‐C:H substrates were increased by increasing of Cu content. The obtained results indicated that by increase of Cu content, all films exhibited high‐absorption spectra; therefore, we were facing an increase in the energy gap of films. The values of dT/dλ and dR/dλ measurements for grown CNTs with 75% Cu shown that maximum values of optical band gap correspond to with values of 2.48 eV and 2.90 eV, respectively. It can be seen that with increase of average diameter of the grown CNTs, the values of Urbach energy of films were increased. The RBS and EDAX measurements were confirmed presence of Ni and Cu atoms into films. The films deposited with 75% Cu were more smooth. Films deposited with 75% Cu have more disordered. Films deposited with 75% Cu atoms have maximum values of the oscillator strength f and the dispersion energy Ed about of 0.108 eV2 and 0.0543 eV, respectively. [ABSTRACT FROM AUTHOR]

Anthocyanins and pyranoanthocyanins are flavonoids that are present in various food products (e.g. fruit, vegetables, wine, etc.). The large chemical diversity amongst these molecules leads to compound‐specific properties such as color and stability towards external conditions. These properties are also attractive for food and non‐food applications. The photophysical experimental characterization is not easy as this generally demands advanced analytical techniques along with optimized separation procedures. Molecular modeling can provide insights into the fundamental understanding of the photophysical properties of these compounds in a uniform way for a broad set of compounds. However, the current literature is quite fragmented on this topic. Herein, a large set of 140 naturally derived anthocyanins was evaluated in a systematic way with three functionals (B3LYP, PBE0, and CAM‐B3LYP). The accuracy of these functionals was determined with experimental literature λmax,vis values. In addition to λmax,vis values, time‐dependent (TD)‐DFT calculations also provided oscillator strengths, molar absorption coefficients, and orbital energies, which define whether specific natural anthocyanin‐based compounds can be deployed in food and non‐food applications such as food additives/colorants, textile dyeing, analytical standards, and dye‐sensitized solar cells (DSSCs). [ABSTRACT FROM AUTHOR]

Nd 3 + /Yb 3 + co-doped lutetium-based glass sample and glass ceramic sample were prepared with the molar ratios of 52SiO2-8Na2CO3-16Al2O3-33NaF-3LuF3-0.15Yb2O3-0.03Nd2O3 by the high temperature melting method in 1400∘C. Under the excitation of 980 nm diode laser, up-conversion luminescence spectrum of glass sample and glass ceramic sample was measured and three stronger up-conversion luminescence peaks at the wavelength of 552 nm, 656 nm and 668 nm were observed, and up-conversion luminescence strengths of glass ceramic sample are higher than those of glass sample. The two-photon absorption of three emission peaks was determined by the fitting curve graph of up-conversion emission power and LD wording current. Absorption spectrum of glass ceramic sample was obtained and spectral strength parameters were computed as Ω 2 = 2. 9 7 × 1 0 − 2 0 cm2, Ω 4 = 0. 5 4 × 1 0 − 2 0 cm2, Ω 6 = 3. 5 8 × 1 0 − 2 0 cm2 by adopting Judd–Ofelt theory, and the root mean square deviation between the theoretical oscillator strength and the experimental oscillator strength were calculated as δ rms = 1. 4 1 × 1 0 − 6 . Transition probability, branching ratio of 4F 3 ∕ 2 to its lower level and lifetime of 4F 3 ∕ 2 level of Nd 3 + ions were calculated, and the results indicate that the prepared Nd 3 + /Yb 3 + co-doped glass ceramic sample is a kind of good up-conversion material. [ABSTRACT FROM AUTHOR]

Atoms subjected to extreme environmental conditions are of fundamental importance due to the modification of their electronic properties. In this work, we study the helium atom when immersed in a plasma environment. In order to describe the plasma medium, we use two models when solving the Schrödinger equation in a restricted Hartree–Fock approach: the Debye–Hückel screened (DHS) potential and a more general exponential-cosine screened Coulomb (ECSC) potential. The plasma length parameter, λ , in both model potentials characterizes the plasma screening effects which cause an increase or decrease in the electronic properties of the helium atom. We report results for the total electronic ground state energy, orbital energy, dipole oscillator strengths, generalized oscillator strengths (GOS), mean excitation energy, electrostatic dipole polarizability, and electronic stopping cross section. We find that the ECSC plasma model produces a less bound system than the DHS plasma model at the same value of the screening length, λ . However, the ECSC model potential has a stronger dipole transition from the 1s to the 2p and 3p states than the DHS model potential. Also, the ECSC potential predicts a higher static dipole polarizability than the DHS model potential, with a consequent lower mean excitation energy. We also find a larger GOS for the ECSC than for the DHS for the same momentum transfer at the same value of the screening length, λ . Consequently, the ECSC mode potential produces a larger electronic stopping cross section than the DHS for the same λ and projectile velocity. In the limit of λ → ∞ , we have excellent agreement with the free helium properties. These quantitative values for the electronic properties would be useful for the investigations of the atomic structure and collisions of helium atoms immersed in plasmas. [ABSTRACT FROM AUTHOR]

The multipole polarizabilities for hydrogen-like atoms with Hulthén potential are calculated with the sum-over-states formalism where the system bound and pseudocontinuum states are produced by employing the generalized pseudospectral method. Energies for nonzero angular momentum states, transition oscillator strengths, and dipole polarizabilities for the ground state of H atom with HP are calculated with high accuracy and compared with previous calculations. Quadrupole, octupole, and hexadecapole polarizabilities for both the ground and excited states are reported for the first time. The combined effect of Hulthén potential and impenetrable sphere on the polarizabilities is investigated, and the relation of such system with the confined H atom and particle in a box is discussed. Further comparison among Hulthén, screened Coulomb, and exponential cosine screened Coulomb potentials reveals that although the ground state energies follow the comparison theorem very well, their first-order energy corrections show complicated variations. [ABSTRACT FROM AUTHOR]

We propose an IoT suppo1t system for estimating the posture of the care recipient on the bed from the body pressure of the care recipient measured by a sheet-type body pressure sensor, and detecting the posture related to leaving the bed in real time. In addition, we propose a method that predicts getting out of the bed before the care recipient takes a posture related to getting out of the bed by considering the state transition. Intervention experiment showed that using body pressure features as an explanatory variable and applying machine leaming, 16 types of postures on the bed of care recipients with an F value of 0.7 or more could be identified. From the experiment without intervention, by applying the hidden Markov model, we calculated the transition probability to each hidden state when the care recipient getting out of the bed and the transition probability to each hidden state when the care recipient not getting out of the bed. As a result, there was a difference of about 0.1 in the transition probability of the state related to raising upper body. [ABSTRACT FROM AUTHOR]

Binding energies, oscillator strengths, and polarizabilities of hydrogen-like atoms embedded in dense quantum plasmas are calculated in high precision by employing the generalized pseudospectral method. Benchmark predictions of these quantities are obtained for both the ground and excited states including high-order transitions. The critical behaviour of system eigenenergies, radial mean values, oscillator strengths, and multipole polarizabilities for bound states when they approach to the corresponding continuum limit as increasing the plasma screening strength are investigated in detail. It is shown that near the critical screening parameters the quantities in s-wave states show distinct behaviour from those in non-s states and such phenomenon is attributed to the divergent asymptotic form of wave functions caused by the centrifugal potential of orbital angular momentum. Based on the power laws of energies and radial mean values extracted from numerical calculations and the approximate formulae for dipole polarizabilities, the critical behaviour of the 2k-pole polarizability of s-wave states is explicitly derived and numerically validated to follow a power law with the exponent −2(k + 1). [ABSTRACT FROM AUTHOR]

A new type of triazolotriazine acceptor has been designed to construct highly efficient TADF materials by fusing triazine and triazole together and achieve the state-of-the-art performance yellow TSF-OLEDs. [Display omitted] Thermally activated delayed fluorescence (TADF) sensitized fluorescent organic light-emitting diodes (TSF-OLEDs) have shown great potential for the realization of high efficiency with low efficiency roll-off and good color purity. However, the superior examples of TSF-OLEDs are still limited up to now. Herein, a trade-off strategy is presented for designing efficient TADF materials and achieving high-performance TSF-OLEDs via the construction of a new type of triazolotriazine (TAZTRZ) acceptor. The enhanced electron-withdrawing ability of TAZTRZ acceptor, fused by triazine (TRZ) and triazole (TAZ) together, enables TADF luminogens with small singlet-triplet energy gap (Δ E ST) values. Meanwhile, the increased planarity from the TRZ-phenyl linkage (6:6 system) to the TAZ-phenyl linkage (5:6 system) can compensate the decrease of oscillator strength (f) while lowing Δ E ST , thus achieving a trade-off between small Δ E ST and high f. As a result, the related TSF-OLED achieved an extremely low turn-on voltage of 2.1 V, an outstanding maximum external quantum efficiency (EQE max) of 23.7% with small efficiency roll-off (EQE 1000 of 23.2%; EQE 5000 of 20.6%) and an impressively high maximum power efficiency of 82.1 lm W−1, which represents the state-of-the-art performance for yellow TSF-OLEDs. [ABSTRACT FROM AUTHOR]

We study a cross-cavity quantum Rabi model with ultrastrong coupling, and its analytical ground state is demonstrated to be approximately obtained by using the rotating-transformation method. Our method requires making three unitary transformations to the original Hamiltonian and ignoring the three-party cross interaction. In near-resonance and ultrastrong-coupling regimes, the ground-state fidelity is higher than 99% for a ±20% detuning range. We analytically demonstrate that the entanglement in ground state first quadratically increases with the qubit-oscillator coupling strength, then gets close to the maximum value 1. The oscillator's nonclassical property in the ground state is well explained by analytically solving the Wigner function. [ABSTRACT FROM AUTHOR]

The generalized oscillator strengths (GOSs) of the valence-shell excitations of CH3Cl have been determined at an incident electron energy of 1500 eV and an energy resolution of about 70 meV. The momentum transfer dependence behaviors of the GOSs of the valence-shell excitations have been carefully analyzed, and the A band shows a strong dipole-forbidden characteristic. By extrapolating the GOSs to the limit of a zero squared momentum transfer, the optical oscillator strengths have been obtained, which provide an independent cross-check for the previous experimental and theoretical results. The BE-scaled integral cross sections (where B is the binding energy and E is the excitation energy) of the valence-shell excitations of CH3Cl have been derived systematically from the threshold to 5000 eV with the aid of a BE-scaling method. The results provide the fundamental spectroscopic data of CH3Cl and have important applications in photochemical modeling for atmospheric physics. [ABSTRACT FROM AUTHOR]

Structure properties of flocs (size, fractal dimension (D f), etc.) have a high impact on coagulation efficiency. In this work, the influences of three different additives (ferric salt (Fe), phosphate (P), and citric acid (CA)) on coagulation process/efficiency were investigated. Results showed that a small amount of extra Fe can facilitate the growth of Al flocs by providing more 'active sites'. Although zeta potential and D f showed a limited change, the average floc size increased apparently and the increment was more obvious when Fe was added after the formation of the flocs. In contrast, P addition during the rapid mixing period will decrease the final average floc size, while the influence is less significant when P was added after the growth of the flocs. In terms of CA, a more striking negative effect on the growth ability of the flocs was observed compared to P. The strong complexing/coordination interactions between CA and aluminum hydroxide is the main reason behind the influence. CA also significantly decreased the D f value of the flocs compared to P, and D f showed a comparatively higher decrease when P or CA was added during the rapid mixing stage compared to the addition after the flocs formation. These results indicated that the addition of CA or P during the rapid mixing stage 'inactivated' or occupied more 'active sites' on the preliminarily formed Al NPs during the hydrolysis process, and therefore presented stronger impact on the morphology/size of the formed flocs. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Let f (D (i , j) , d i , d j) be a real function symmetric in i and j with the property that f (d , (1 + o (1)) n p , (1 + o (1)) n p) = (1 + o (1)) f (d , n p , n p) for d = 1 , 2. Let G be a graph, d i denote the degree of a vertex i of G and D (i , j) denote the distance between vertices i and j in G. In this paper, we define the f -weighted Laplacian matrix for random graphs in the Erdös-Rényi random graph model G n , p , where p ∈ (0 , 1) is fixed. Four weighted Laplacian type energies: the weighted Laplacian energy LE f (G) , weighted signless Laplacian energy LE f + (G) , weighted incidence energy IE f (G) and the weighted Laplacian-energy like invariant LEL f (G) are introduced and studied. We obtain the asymptotic values of IE f (G) and LEL f (G) , and the values of LE f (G) and LE f + (G) under the condition that f (D (i , j) , d i , d j) is a function dependent only on D (i , j). As a consequence, we get that under the condition that f (D (i , j) , d i , d j) is a function dependent only on D (i , j) , for almost all graphs G p ∈ G n , p , the energy for the matrix with degree-distance-based entries of G p , E (W f (G p)) < LE f (G p) , the Laplacian energy of the matrix, which can be viewed as a generalization of a conjecture by Gutman et al. [ABSTRACT FROM AUTHOR]

In the present study glass samples of (40 – x)Li20 · xNa2O · 10K2O · 50B2O3 and (40 ‒ x)Li2O · xK2O · 10Na2O · 50B2O3 (0 ≤ x ≤ 40 mol %) were prepared by melt quench technique. The cut-off wavelength varies non-linearly when Li2O is replaced with Na2O or K2O. The type of electronic transition in the present glass systems is indirect allowed. Using single oscillator model, the oscillator energy E0, the dispersion energy Ed, the static refractive index n0, the oscillator strength S0 and average oscillator wavelength λ0 were determined. The ratio of free carrier concentration to the free carrier effective mass Nc/m*, the optical relaxation time τ and ε∞ the high frequency dielectric constant were determined in the present glass systems. The real and imaginary parts of the optical conductivity dependence of energy in present glasses increases non-linearly with increasing photon energy. [ABSTRACT FROM AUTHOR]

We present experimental electron-energy loss spectra (EELS) that were measured at impact energies of 20 and 30 eV and at angles of 90° and 10°, respectively, with energy resolution ~70 meV. EELS for 250 eV incident electron energy over a range of angles between 3° and 50° have also been measured at a moderate energy resolution (~0.9 eV). The latter spectra were used to derive differential cross sections and generalised oscillator strengths (GOS) for the dipole-allowed electronic transitions, through normalization to data for elastic electron scattering from benzene. Theoretical calculations were performed using time-dependent density functional theory and single-excitation configuration interaction methods. These calculations were used to assign the experimentally measured spectra. Calculated optical oscillator strengths were also compared to those derived from the GOS data. This provides the first investigation of all singlet and triplet excited electronic states of phenol up to the first ionization potential. [ABSTRACT FROM AUTHOR]

The implementation of an efficient program of the algebraic diagrammatic construction method for the polarisation propagator in third-order perturbation theory (ADC(3)) for the computation of excited states is reported. The accuracies of ADC(2) and ADC(3) schemes have been investigated with respect to Thiel's recently established benchmark set for excitation energies and oscillator strengths. The calculation of 141 vertical excited singlet and 71 triplet states of 28 small to medium-sized organic molecules has revealed that ADC(3) exhibits mean error and standard deviation of 0.12 ± 0.28 eV for singlet states and -0.18 ± 0.16 eV for triplet states when the provided theoretical best estimates are used as benchmark. Accordingly, the ADC(2)-s and ADC(2)-x calculations revealed accuracies of 0.22 ± 0.38 eV and -0.70 ± 0.37 eV for singlets and 0.12 ± 0.16 eV and -0.55 ± 0.20 eV for triplets, respectively. For a comparison of CC3 and ADC(3), only non-CC3 benchmark values were considered, which comprise 84 singlet states and 19 triplet states. For these singlet states CC3 exhibits an accuracy of 0.23 ± 0.21 eV and ADC(3) an accuracy of 0.08 ± 0.27 eV, and accordingly for the triplet states of 0.12 ± 0.10 eV and -0.10 ± 0.13 eV, respectively. Hence, based on the quality of the existing benchmark set it is practically not possible to judge whether ADC(3) or CC3 is more accurate, however, ADC(3) has a much larger range of applicability due to its more favourable scaling of O(N6) with system size. [ABSTRACT FROM AUTHOR]

We examine the excitonic properties of layered configurations of low dimensional transition metal dichalcogenides (LTMDCs) using the fractional dimensional space approach. The binding energies of the exciton, trion, and biexciton in LTMDCs of varying layers are analyzed, and linked to the dimensionality parameter α, which provides insight into critical electro-optical properties (relative oscillator strength, absorption spectrum, exciton-exciton interaction) of the material systems. The usefulness of α is highlighted by its independence of the physical mechanisms underlying the confinement effects of geometrical structures. Our estimates of the binding energies of exciton complexes for the monolayer configuration of transition metal dichalcogenides suggest a non-collinear structure for the trion and a positronium-molecule-like square structure for the biexciton. [ABSTRACT FROM AUTHOR]

We discuss the application of multishift linear system solvers to linear-response time-dependent density functional theory. Using this technique the complete frequency-dependent electronic density response of finite systems to an external perturbation can be calculated at the cost of a single solution of a linear system via conjugate gradients. We show that multishift time-dependent density functional theory yields excitation energies and oscillator strengths in perfect agreement with the standard diagonalization of the response matrix (Casida's method), while being computationally advantageous. We present test calculations for benzene, porphin, and chlorophyll molecules. We argue that multishift solvers may find broad applicability in the context of excited-state calculations within densityfunctional theory and beyond [ABSTRACT FROM AUTHOR]

We report the discovery of finite length scale effects on vibronic coupling in nanoscale α-Fe2O3 as measured by the behavior of vibronically activated d-d on-site excitations of Fe3+ as a function of size and shape. An oscillator strength analysis reveals that the frequency of the coupled symmetry-breaking phonon changes with size, a crossover that we analyze in terms of increasing three-dimensional character to the displacement pattern. These findings demonstrate the flexibility of mixing processes in confined systems and suggest a strategy for both enhancing and controlling charge-lattice interactions in other materials. [ABSTRACT FROM AUTHOR]

In this work, the effects of the shape and size on the intersubband electronic and optical properties of three-dimensional self-assembled pyramid-shaped InAs/GaAs quantum dots (QDs) were investigated in detail. More precisely, in-plane- and z-polarized transitions dipole moment (TDM), oscillator strength (OS), and absorption coefficients of P-to-S, WL-to-P, and WL-to-S transitions were studied as a function of the QD height. The P-to-S TDM showed to be strong and purely in-plane-polarized transition dominating two others. However, the TDMs and OSs of WL-to-P and WL-to-S transitions which are in-plane- and z-polarized transitions, respectively, showed a competition behavior for short and tall QDs. The former dominates for short QDs, and the latter for tall QDs. The physical reasons behind these interesting phenomena were also explained using the probability of finding the carriers in the pyramid region attached to the WL. The theoretical results are in good agreement with experimental data reported for short QDs [Appl. Phys. Lett. 82, 630 (2003)]. [ABSTRACT FROM AUTHOR]

We report the discovery of finite length scale effects on vibronic coupling in nanoscale α-Fe2O3 as measured by the behavior of vibronically activated d-d on-site excitations of Fe3+ as a function of size and shape. An oscillator strength analysis reveals that the frequency of the coupled symmetry-breaking phonon changes with size, a crossover that we analyze in terms of increasing three-dimensional character to the displacement pattern. These findings demonstrate the flexibility of mixing processes in confined systems and suggest a strategy for both enhancing and controlling charge-lattice interactions in other materials. [ABSTRACT FROM AUTHOR]

Intersubband transition energies and absorption lineshape in staggered InGaN/GaN quantum wells surrounded by GaN barriers are computed as functions of structural parameters such as well width, In concentrations, and the doping level in the well. Schrödinger and Poisson equations are solved self-consistently by taking the free and bound surface charge concentrations into account. Many-body effects, namely, depolarization and excitonic shifts are also included in the calculations. Results for transition energies, oscillator strength, and the absorption lineshape up to nonlinear regime are represented as functions of the parameters mentioned. The well width (total and constituent layers separately) and In concentration dependence of the built-in electric field are exploited to tune the intersubband transition energies. [ABSTRACT FROM AUTHOR]

There have been many observations of the solar and astrophysical spectra of various ions. The diagnostics of these observations require atomic data that include energy levels, oscillator strengths, transition rates, and collision strengths. These have been calculated using the Superstructure and Distorted-wave codes. We describe calculations for various ions. We calculate intensity ratios and compare them with observations to infer electron densities and temperatures of solar plasmas.

Background: Left atrial (LA) volume (LAV) is one of the recommended key variables for evaluating left ventricular (LV) diastolic function. However, only LA anteroposterior diameter (LAAP) is available in numerous large-scale existing databases. Therefore, this study aimed to validate whether LV diastolic function could be evaluated with estimated LAV from LAAP.Methods: A total of 552 inpatients with sinus rhythm were consecutively enrolled. LAV was measured by biplane Simpson's disk summation method. LV diastolic function was evaluated according to the 2016 proposed recommendations. Best-fitting regression models of LAAP index (LAAPI)-LAV index (LAVI) were developed and equations with the highest F-value were chosen in the first 276 subjects (derivation set), and concordance for evaluating LV diastolic function between using estimated and observed LAVI was verified in the remaining 276 subjects (validation set).Results: In the derivation set, the linear model has the highest F-value in all subjects and in the subjects with normal or depressed LV ejection fraction. In the validation set, using the linear equation (LAVI = 2.05 × LAAPI - 13.86), the higher area under curve and narrower range of difference were shown between estimated LAVI and observed LAVI, respectively. Further, concordance for diagnosis (overall proportion of agreement, 88.4%; κ = 0.79) and grading (overall proportion of agreement, 84.8%; κ = 0.74) of LV diastolic dysfunction was substantial between using estimated and observed LAVI.Conclusions: LV diastolic function can be evaluated with estimated LAVI from LAAPI, which might provide a surrogate method when the direct measurement of LAV is not available. [ABSTRACT FROM AUTHOR]

Nonlinear optical frequency mixing, which describes new frequencies generation by exciting nonlinear materials with intense light field, has drawn vast interests in the field of photonic devices, material characterization, and optical imaging. Investigating and manipulating the nonlinear optical response of target materials lead us to reveal hidden physics and develop applications in optical devices. Here, we report the realization of facile manipulation of nonlinear optical responses in the example system of MoS2 monolayer by van der Waals interfacial engineering. We found that, the interfacing of monolayer graphene will weaken the exciton oscillator strength in MoS2 monolayer and correspondingly suppress the second harmonic generation (SHG) intensity to 30% under band-gap resonance excitation. While with off-resonance excitation, the SHG intensity would enhance up to 130%, which is conjectured to be induced by the interlayer excitation between MoS2 and graphene. Our investigation provides an effective method for controlling nonlinear optical properties of two-dimensional materials and therefore facilitates their future applications in optoelectronic and photonic devices. [ABSTRACT FROM AUTHOR]

Comprehensive large scale atomic spectral data calculations were performed for a Be-like tungsten ion (W70+), starting from a shell number n = 2, through n = 3, 4, 5, 6, 7, and ending at a shell number n = 8. We applied the relativistic configuration interaction method of the flexible atomic code. The generated data include detailed information concerning allowed and forbidden transitions, together with transition energies, transition wavelengths, transition rates and oscillator strengths for electric-dipole (E1), electric-quadruple (E2), electric-octupole (E3), magnetic-dipole (M1), magneticquadruple (M2) and magnetic-octupole (M3) transitions. The produced atomic data are satisfactory when compared to the previously published results calculated by GRASP2K code. The procured multipole transitions data were used to construct synthetic spectra for allowed and forbidden transitions of W70+. We simulated the experimental spectra of low-density W plasma and found the spectral range 0.6-1.4 Å. The produced atomic data is important for several research branches, including fusion research and plasma physics. [ABSTRACT FROM AUTHOR]

Two cubic garnet-structured Sr 3 B 2 Ge 3 O 12 (B = Yb, Ho; called SYG and SHG) ceramics synthesised by the high-temperature solid-phase reaction method were investigated in terms of phase formation, sintering behaviour and microwave dielectric performance. At their optimal sintering temperatures, SYG had low dielectric constant (ε r) = 9.30, high quality factor (Q × f) = 129,360 GHz and negative temperature coefficient of resonant frequency (τ f) =−42 ppm/℃, whereas SHG exhibited low ε r = 9.23, Q × f = 104,600 GHz, and comparatively near-zero τ f =−26 ppm/℃. The difference in microwave dielectric performance of both ceramics was discussed by the packing fraction, full width at half maximum (FWHM) of A 1g Raman mode at 779 cm−1 (775 cm−1) and bond valence. The intrinsic dielectric properties of SYG and SHG ceramics were investigated by the infrared reflectivity spectra, and their negative τ f values were tuned to near-zero. [ABSTRACT FROM AUTHOR]

CaTi 1-x (Mg 1/2 W 1/2) x O 3 (x = 0, 0.02, 0.04, 0.06, 0.08) dielectric ceramics were synthesized via the traditional solid-state reaction method. Crystal structure and microwave dielectric properties of CaTi 1-x (Mg 1/2 W 1/2) x O 3 system were systematically investigated based on chemistry bond theory (P–V-L theory) for the first time. The pure perovskite phase was obtained for all doped samples, as confirmed through the XRD and Rietveld refinement results. The lattice characteristics were closely related to the microwave dielectric properties. The bond ionicity, lattice energy, and bond energy affected the dielectric constant, quality factor, and temperature stability of the ceramic material. Through the use of (Mg 1/2 W 1/2)4+ doped on B-site, the CaTi 1-x (Mg 1/2 W 1/2) x O 3 system can maintain a high dielectric constant (ε r > 100) while effectively reducing the τ f value from 800 ppm/°C to less than 300 ppm/°C and improving the Q × f value to 9650 GHz (at 3.76 GHz). [ABSTRACT FROM AUTHOR]

Functionalized octamers of polyaniline neutral forms (leucoemeraldine, emeraldine, pernigraniline) were studied in order to optimize the first hyperpolarizabilities (β). Remarkable static β values were found for the pernigraniline and emeraldine derivatives by using the coupled perturbed Kohn‐Sham (CPKS) approach at the PBE1PBE/6‐31G** level. The enhanced nonlinear response was achieved through the introduction of donor (D) and/or acceptor (A) groups into the oligoanilines structures. The nonlinear optical (NLO) properties of the octamers missing the substituent groups were also investigated. The largest β values were obtained for the pernigraniline and emeraldine derivatives having the tert‐butyl (D) and dicyanoethenyl (A) substituents at opposite ends, as well as the ones with only the acceptor group. These oligomers show charge transfer transitions with large oscillator strengths according to the time dependent density functional theory (TD‐DFT). Predicted β values for the majority of functionalized oligoanilines strongly indicate them as potential building blocks for molecular‐based nonlinear materials with second‐order response. [ABSTRACT FROM AUTHOR]

Infrared (IR) and terahertz plasmons in two-dimensional (2D) materials are commonly excited by metallic or dielectric grating couplers with deep-submicron features fabricated by e-beam lithography. Mass reproduction of such gratings at macroscopic scales is a labor-consuming and expensive technology. Here, we show that localized plasmons in graphene can be generated on macroscopic scales with couplers based on randomly oriented particle-like nanorods (NRs) in close proximity to graphene layer. We monitor the excitation of graphene plasmons indirectly by tracking the changes in reflection/absorption spectra of methylene blue (MB) or polymethyl methacrylate(PMMA) molecules deposited on the structure. Hybridization of spectrally broad graphene plasmon and narrow molecular oscillators results in enhanced oscillator strengths and Fano scattering related lines asymmetry in reflection spectra. [ABSTRACT FROM AUTHOR]

The existence of one-way functions seems to depend, intuitively, on certain irregular properties of polynomial-time computable functions. Therefore, for functions with continuity properties, it suggests that all such functions are not one-way. It is shown here that in the formal complexity theory of real functions, this nonexistence of continuous one-way functions can be proved for one-to-one one-dimensional real functions, but fails for one-to-one two-dimensional real functions, if certain strong discrete one-way functions exist. Furthermore, for k -to-one functions, we can prove the existence of four-to-one one-dimensional one-way functions under the same assumption of the existence of strong discrete one-way functions. (A function f is k -to-one if for any y there exist at most k distinct values x such that f (x) = y.) [ABSTRACT FROM AUTHOR]

Na 2 B 4 O 7 ·10H 2 O (borax) doped Sr 3 (VO 4) 2 ceramics for ULTCC applications were synthesized by the solid-state reaction. The influence of borax addition on the sintering characteristic, microstructure, and microwave dielectric properties of Sr 3 (VO 4) 2 ceramics was investigated in detail. The result indicated that borax was an effective sintering aid for the Sr 3 (VO 4) 2 system and a suitable amount of borax dramatically reduced the sintering temperature of Sr 3 (VO 4) 2 ceramics from 1000 to 675 °C. Meanwhile, borax addition prevented the Q × f value from getting degenerated and improved the τ f value of Sr 3 (VO 4) 2 ceramics in the case of ultra-lower sintering temperatures. Novel Sr 3 (VO 4) 2 + 1 wt% borax ceramic sintered at 675 °C with optimum properties of Q × f = 19,200 GHz, ε r = 15.9, and τ f = 10.9 ppm/°C was achieved in this study. [ABSTRACT FROM AUTHOR]

Let G be a graph with diameter d. A radio labelling of G is a function f that assigns to each vertex with a non-negative integer such that the following holds for all vertices u , v : | f (u) − f (v) | ⩾ d + 1 − d (u , v) , where d (u , v) is the distance between u and v. The span of f is the absolute difference of the largest and smallest values in f (V). The radio number of G is the minimum span of a radio labelling admitted by G. For trees, a general lower bound of the radio number was given by Liu [10] , which has been used to prove special families of trees whose radio number is equal to this bound [1,6,9,10]. In this article, we present improved lower bounds for some trees whose radio number exceeds Liu's lower bound. Some of these new bounds are sharp for special families of trees, including complete binary trees [9] and odd paths [11]. Moreover, using these new bounds, we extend the known results of Halasza and Tuza [6] on complete level-wise regular trees. [ABSTRACT FROM AUTHOR]

Statistical optimization of hydrolytic conditions for the production of fructooligosaccharides (FOSs) from pure inulin using Aspergillus tritici endoinulinase was carried out in a batch system. FOSs yield 99.19% was obtained under the optimized hydrolytic conditions i.e. inulin concentration (7.3%), enzyme load (65 IU), hydrolysis time (13 h) and agitation (100 rpm). The closeness of value of co-efficient of determination (R 2 ) to 1, good agreement between model's predicted and experimental values, low percentage error (<5%), high adequate precision (>4%) and F value (11,634.32), and low Lack of fit (0.60) of the designed model authenticates its fitness. High substrate concentration, low enzyme load and short hydrolysis span justifies efficiency of developed process for the preparation of FOSs from inulin using fungal endoinulinase. TLC chromatographic and densitometry studies confirmed the synthesis of short-chain length FOSs. FOSs preparation contained 33.85% GF2 (ketose), 24.50% GF3 (nystose), 7.26% GF4 (fructofuranosylnystose) and 33.58% FOSs of DP5–9. • Statistical optimization of hydrolytic conditions supported 99.19% FOSs yield. • Short inulin hydrolysis time (13 h) would be useful for the development of an economical bioprocess. • Agitation mode of inulin hydrolysis was found efficient for FOSs production. • FOSs of varied degree of polymerization (2–9) were produced from inulin by fungal endoinulinase. [ABSTRACT FROM AUTHOR]

Fraction unbound (f u) is an important consideration when characterizing the ADME properties of drug candidates. For highly bound compounds, there can be low confidence in quantifying f u introducing uncertainty in certain parameter estimations. Specifically, predictions of clearance (CL) rely on accurate f u values measured in plasma (f u,p) and microsomes (f u,mic) to scale in vitro intrinsic CL to in vivo CL. However, determining the ratio of f u,p /f u,mic may circumvent the need to measure discrete binding values. The purpose of this study was to evaluate a plasma-to-microsome competitive equilibrium dialysis (cED) method to determine f u,p /f u,mic ratio (fuR) for nine physiochemically-distinct compounds, and to investigate the impact of altering microsomal concentrations on fuR. The values of fuR were comparable to ratios calculated from discretely measured f u,p and f u,mic values. Furthermore, increasing microsomal concentrations increased fuR for basic and neutral compounds. When using fuR values, there was a good in vitro-in vivo correlation (IVIVC) (≤3-fold observed in vivo CL). These results suggest that the cED method used to determine fuR may be an appropriate, alternative IVIVC approach. Application of cED may extend beyond IVIVC of CL to evaluate other parameters such as species differences in protein binding and free tissue to plasma ratios. [ABSTRACT FROM AUTHOR]

We report on time-dependent density functional theory calculations to study the chiroptical properties of small Nb 9 clusters and their corresponding van der Waals Nb 9 Ar n complexes. The three most stable 9-atom structures considered in the literature are analyzed, and we obtain their lowest-energy atomic configurations, UV–Vis response, and for the first time, the electronic circular dichroism (ECD) spectra of the systems. Excitation energies, as well as oscillator and rotational strengths are calculated using the M06 exchange-correlation functional together with a mixed basis approach where all electron DGDZVP and Def2SV basis are employed for Nb and Ar atoms, respectively. In all cases, the UV–Vis spectra look very similar and are characterized by the formation of a main absorption maxima located at ∼ 240 nm ; however, the distribution of simulated ECD signals strongly depends on the geometrical structure of the clusters. Our calculated ECD bands show precise features that cover the experimentally accessible 200–300 nm range and extend near the visible part of the spectra, a fact that allows us to distinguish between different niobium cluster geometries. However, weighted averages of calculated ECD spectra for different Nb 9 clusters reveal that isomerization effects might lead to a notable increase/reduction in the intensity of CD lines since the simulated bands could add or cancel each other. [ABSTRACT FROM AUTHOR]

• The F10.7 SA index poorly describes the foF2 behavior during the 24th cycle. • Correction of F10.7 by the Rz, Ly, and Mg II indices is needed. • The correction provides negative foF2 trends until 2019. The analysis of the behavior of the critical frequency foF 2 during the 24th solar activity cycle (Danilov and Konstantinova, 2020a, c) is prolonged for two more months and the nighttime hours. In addition to the Rz and Ly-α indices used in the aforementioned papers for correction of the F 10.7 index during the 24th cycle, the commonly used Mg II index is added. The results confirm the previous conclusions on the existence of the "vague" period with chaotic behavior of foF 2 and the recovery of the negative trend in foF 2 after 2008–2010. A comparison of the F 10.7 index with three other SA indices (Ly-α, Rz , and Mg II) for the 22nd, 23rd, and 24th SA cycles is performed. It is shown that the relationship between F 10.7 and other indices is close in the 22nd and 23rd cycles but differs from that in the 24th cycle. The corrected values of F 10.7 in the 24th cycle are proposed for analysis of ionospheric trends during that cycle. [ABSTRACT FROM AUTHOR]

A unified framework for describing dense plasma screenings from warm dense matter to hot dense matter, including gradient correction and exchange-correlation, has been recently proposed by Stanton and Murillo [Phys. Rev. E 91,033104 (2015)]. With this unified description of linear screening, the energy levels, absorption oscillator strengths, and radiative transition probabilities of hydrogen-like plasmas are reported for a wide range of critical screening parameters (plasma temperatures and densities), where the bound level nl merges into continuum. The importance of both finite temperature gradient correction and exchange correlation increases with the increasing plasma coupling strength or the Coulomb coupling parameter Γ, and the effect of exchange correlation is generally greater than that of finite temperature gradient correction. Further results from the weakly coupled and strongly coupled limits or Debye plasmas and dense quantum plasmas also show consistency with those from the unified framework, respectively. [ABSTRACT FROM AUTHOR]

In this paper, Ba(Mg1/3Nb2/3)O3 (BMN) ceramics with x (x = 0–9) wt% BaWO4 were synthesized using the conventional solid-state sintering technique. Effects of BaWO4 addition on the microstructure and microwave dielectric properties of BMN ceramics were evaluated. X-ray diffraction (XRD) analysis showed that there were three phases: main crystalline phase Ba(Mg1/3Nb2/3)O3 and secondary phases BaWO4 and Ba5Nb4O15. Meanwhile, the (100) super-lattice reflection peaks shifted to a higher 2θ angle with increasing BaWO4 content. SEM photographs suggested that BaWO4 working as a sintering additive promoted the densification and grain growth. The dielectric properties were examined by Vector network analyzer. The dielectric constant (εr) was largely determined by the relative density and phase composition. Meanwhile, the addition of BaWO4 had a positive effect on the Q × f value, for example the specimen with x = 5 possessed the highest Q × f value of 111,300 GHz. Optimum microwave dielectric properties (εr = 31.7, Q × f = 111,300 GHz (f = 8 GHz) and τf = 0.16 ppm/°C) were obtained for the specimen with x = 5 sintered at 1350 °C for 6 h. [ABSTRACT FROM AUTHOR]

Simultaneous effects of hydrostatic pressure and the geometrical confinement on the excitonic and some nonlinear optical properties of an exciton confined in an InP/ZnS core/shell quantum dot are investigated. Pressure associated exciton binding energy, oscillator strength, absorption coefficient, changes of refractive index and optical Raman gain are brought out for various values of ratio of radii of core/shell quantum dot. The results show that the binding energy of the exciton enhances with the application of hydrostatic pressure for all the ratio of radii. The enhancement of resonance amplitude and shifting towards the higher energies in absorption spectra is noted with the applied pressure and the peak values of refraction properties are found to reduce monotonically. The bare broad Raman band is observed at 335 cm−1 and this band shifts towards the higher values when the hydrostatic pressure is applied. They are in good agreement with the existing available literature. [ABSTRACT FROM AUTHOR]

High-accuracy calculations of energy levels, wavelengths, probabilities, and oscillator strengths of transition of resonance lines for Ge-like Pd, Ag, and Cd ions have been performed. For the accurate treatment of relativity, the contributions of Breit interactions and quantum electrodynamics correction were considered. The calculated values of energy levels and wavelengths, including core–valence corrections, are found to be in excellent agreement with other theoretical and experimental values for Ge-like Pd, Ag, and Cd ions. The number of energy levels and wavelengths we considered is larger than that of any other theoretical calculations. The transition probabilities are also given where no other theoretical results and experimental values are available. [ABSTRACT FROM AUTHOR]

In this paper, a Zn - Cu mosaic target was used for fabricating of copper doped ZnO films using RF magnetron co-sputtering with oxygen and argon gases in room temperature. After the deposition of copper doped ZnO films, then films were annealed at different temperatures of 400, 500 and 600°C in an electrical furnace in the presence of argon gas. The positions of obtained peaks for the photoluminescence spectra were estimated to be 379, 424, 481 and 531 nm which they corresponding to ultraviolet and visible regions. Transmittance T(λ) and reflectance R(λ) spectra of copper doped ZnO films were used to estimate of gap states with different methods. The copper doped ZnO films annealed at 400°C were more disordered. The copper doped ZnO films annealed at 600°C have minimum values of oscillator strength S0 in about of 17.33 μm−2. The copper doped ZnO films annealed at 500°C have maximum values of dispersion energy Ed and the oscillator strength f in about of 2.51 eV and 48.63 eV2, respectively. [ABSTRACT FROM AUTHOR]