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Optical trapping is an effective tool for manipulating micrometer-sized particles, although its application to nanometer-sized particles remains difficult. The field of optical trapping has advanced significantly, incorporating more advanced techniques such as plasmonic structures. However, single-molecule trapping remains a challenge. To achieve a deeper understanding of optical forces acting on molecular systems, a first-principles approach to analyze the optical force on molecules interacting with a plasmonic field is crucial. In our study, the optical force and torque induced by the near-field excitation of C3H6 were investigated using real-time time-dependent density functional theory calculations on real-space grids. The near field from the scanning tunneling probe was adopted as the excitation source for the molecule. The optical force was calculated using the polarization charges induced in the molecule based on Lorentz force. While the optical force and torque calculated as functions of the light energy were in moderate agreement with the oscillator strengths obtained from the far-field excitation of C3H6, a closer correspondence was achieved with the power spectrum of the induced dipole moment using near-field excitation. Time-domain analysis of the optical force suggests that the simultaneous excitation of multiple excited states generally weakens the force because of mismatches between the directions of the induced polarization and the electric field. This study revealed a subtle damping mechanism for the optical force arising from intrinsic electronic states and the influence of beating. [ABSTRACT FROM AUTHOR]

The high resolution Rydberg absorption spectrum of 2-butyne C4H6 recorded previously at the SOLEIL synchrotron facility has been interpreted using multichannel quantum defect theory (MQDT). The calculations are based on the continuum scattering calculations of Xu et al., J. Chem. Phys. 136, 154303 (2012) and of Jacovella et al., J. Phys. Chem. A 119, 12339 (2015) pertaining to the dipole-allowed excited state symmetries in absorption from the ground state. In contrast to the traditional approach of calculating low-lying electronic states first and then attempting to extend the calculations to ever higher energy, here the analysis proceeds through the extension of these detailed calculations of the electronic continuum scattering down into the discrete region of the spectrum. The continuum reaction matrices and dipole transition moments are adapted to the discrete Rydberg region via the use of an energy-modified formulation of MQDT theory and associated energy dependences of the quantum defects. The analysis reproduces more than 40 Rydberg states from n ≈ 10 down to the 3d and 4s levels with an rms error of better than 20 cm−1. These belong to five Rydberg series with three different molecular symmetries. While the approach predicts many additional series, most of these are calculated and observed to carry only little oscillator strength. The analysis shows that the Rydberg spectrum is dominated by the excitation of an e″ symmetry electron of fδ and gπ type, in line with what previous studies of the above-threshold shape resonance of 2-butyne have shown. The present study is intended to serve as an example showing how first principles continuum calculations may be useful for the interpretation of highly bound discrete states in a range that poses problems for the standard ab initio techniques. The quantitative treatment of the dipole absorption cross sections is deferred to a future paper. [ABSTRACT FROM AUTHOR]

A holistic computational analysis is developed to calculate the quantum efficiency of InAs/GaSb superlattice-based photodetectors. Starting with the electronic band characteristics computed by taking InSb/GaAs at the interface using the 8-band k. p approach, we demonstrate the impact of InAs and GaSb widths on the bandgap, carrier concentration, and the oscillator strength for type-II superlattice absorbers. Subsequently, the alteration of these characteristics due to the extra AlSb layer in the M superlattice absorber is investigated. Extending our models for determining TE- and TM-polarized optical absorption, our calculations reveal that the TE-polarized absorption shows a substantial influence near the conduction-heavy hole band transition energy, which eventually diminishes, owing to the dominant TM contribution due to the conduction-light hole band transition. Extending our analysis to the dark currents, we focus mainly on Schokley–Read–Hall recombination and radiative recombination at lower temperatures and show that Schokley–Read–Hall dominates at low-level injection. We show that short-wavelength and mid-wavelength M superlattice structures exhibit higher quantum efficiency than the corresponding same bandgap type-II superlattice with the lower diffusion dark current. Furthermore, we analyze the density of states blocked by the barrier, crucial for XBp photodetector after absorber examination. Our work, thus, sets a stage for a holistic and predictive theory aided analysis of the type-II superlattice absorbers, from the atomistic interfacial details all the way to the dark currents and absorption spectra. [ABSTRACT FROM AUTHOR]

The authors previously developed a divide-and-conquer (DC)-based non-local excited-state calculation method for large systems using dynamical polarizability [Nakai and Yoshikawa, J. Chem. Phys. 146, 124123 (2017)]. This method evaluates the excitation energies and oscillator strengths using information on the dynamical polarizability poles. This article proposes a novel analysis of the previously developed method to obtain further configuration information on excited states, including excitation and de-excitation coefficients of each excitation configuration. Numerical applications to simple molecules, such as ethylene, hydrogen molecule, ammonia, and pyridazine, confirmed that the proposed analysis could accurately reproduce the excitation and de-excitation coefficients. The combination with the DC scheme enables both the local and non-local excited states of large systems with an excited nature to be treated. [ABSTRACT FROM AUTHOR]

In the framework of simplified quantum chemistry methods, we introduce the eXact integral simplified time-dependent density functional theory (XsTD-DFT). This method is based on the simplified time-dependent density functional theory (sTD-DFT), where all semi-empirical two-electron integrals are replaced by exact one- and two-center two-electron integrals, while other approximations from sTD-DFT are kept. The performance of this new parameter-free XsTD-DFT method was benchmarked on excited state and (non)linear response properties, including ultra-violet/visible absorption, first hyperpolarizability, and two-photon absorption (2PA). For a set of 77 molecules, the results from the XsTDA approach were compared to the TDA data. XsTDA/B3LYP excitation energies only deviate on average by 0.14 eV from TDA while drastically cutting computational costs by a factor of 20 or more depending on the energy threshold chosen. The absolute deviations of excitation energies with respect to the full scheme are decreasing with increasing system size, showing the suitability of XsTDA/XsTD-DFT to treat large systems. Comparing XsTDA and its predecessor sTDA, the new scheme generally improves excitation energies and oscillator strengths, in particular, for charge transfer states. TD-DFT first hyperpolarizability frequency dispersions for a set of push-pull π-conjugated molecules are faithfully reproduced by XsTD-DFT, while the previous sTD-DFT method provides redshifted resonance energy positions. Excellent performance with respect to the experiment is observed for the 2PA spectrum of the enhanced green fluorescent protein. The obtained robust accuracy similar to TD-DFT at a fraction of the computational cost opens the way for a plethora of applications for large systems and in high throughput screening studies. [ABSTRACT FROM AUTHOR]

Algebraic diagrammatic construction (ADC) is a computationally efficient approach for simulating excited electronic states, absorption spectra, and electron correlation. Due to their origin in perturbation theory, the single-reference ADC methods may be susceptible to spin contamination when applied to molecules with unpaired electrons. In this work, we develop an approach to quantify spin contamination in the ADC calculations of electronic excitations and apply it to a variety of open-shell molecules starting with either the unrestricted (UHF) or restricted open-shell (ROHF) Hartree–Fock reference wavefunctions. Our results show that the accuracy of low-order ADC approximations [ADC(2) and ADC(3)] significantly decreases when the UHF reference spin contamination exceeds 0.05 a.u. Such strongly spin-contaminated molecules exhibit severe excited-state spin symmetry breaking that contributes to decreasing the quality of computed excitation energies and oscillator strengths. In a case study of phenyl radical, we demonstrate that spin contamination can significantly affect the simulated UV/Vis spectra, altering the relative energies, intensities, and order of electronic transitions. The results presented here motivate the development of spin-adapted ADC methods for open-shell molecules. [ABSTRACT FROM AUTHOR]

N-heterocyclic carbene (NHC) iridium(III) complexes are considered as promising candidates for blue emitters in organic light-emitting diodes. They can play the roles of the emitter as well as of electron and hole transporters in the same emission layer. We investigate optical transitions in such complexes with account of geometry and electronic structure changes upon excitation or charging and exciton transfer between the complexes from first principles. It is shown that excitation of NHC iridium complexes is accompanied by a large reorganization energy ∼0.7 eV and a significant loss in the oscillator strength, which should lead to low exciton diffusion. Calculations with account of spin–orbit coupling reveal a small singlet–triplet splitting ∼0.1 eV, whereas the oscillator strength for triplet excitations is found to be an order of magnitude smaller than for the singlet ones. The contributions of the Förster and Dexter mechanisms are analyzed via the explicit integration of transition densities. It is shown that for typical distances between emitter complexes in the emission layer, the contribution of the Dexter mechanism should be negligible compared to the Förster mechanism. At the same time, the ideal dipole approximation, although giving the correct order of the exciton coupling, fails to reproduce the result taking into account spatial distribution of the transition density. For charged NHC complexes, we find a number of optical transitions close to the emission peak of the blue emitter with high exciton transfer rates that can be responsible for exciton–polaron quenching. The nature of these transitions is analyzed. [ABSTRACT FROM AUTHOR]

The absolute photoabsorption cross sections of norbornadiene (NBD) and quadricyclane (QC), two isomers with chemical formula C7H8 that are attracting much interest for solar energy storage applications, have been measured from threshold up to 10.8 eV using the Fourier transform spectrometer at the SOLEIL synchrotron radiation facility. The absorption spectrum of NBD exhibits some sharp structure associated with transitions into Rydberg states, superimposed on several broad bands attributable to valence excitations. Sharp structure, although less pronounced, also appears in the absorption spectrum of QC. Assignments have been proposed for some of the absorption bands using calculated vertical transition energies and oscillator strengths for the electronically excited states of NBD and QC. Natural transition orbitals indicate that some of the electronically excited states in NBD have a mixed Rydberg/valence character, whereas the first ten excited singlet states in QC are all predominantly Rydberg in the vertical region. In NBD, a comparison between the vibrational structure observed in the experimental 11B1–11A1 (3sa1 ← 5b1) band and that predicted by Franck–Condon and Herzberg–Teller modeling has necessitated a revision of the band origin and of the vibrational assignments proposed previously. Similar comparisons have encouraged a revision of the adiabatic first ionization energy of NBD. Simulations of the vibrational structure due to excitation from the 5b2 orbital in QC into 3p and 3d Rydberg states have allowed tentative assignments to be proposed for the complex structure observed in the absorption bands between ∼5.4 and 7.0 eV. [ABSTRACT FROM AUTHOR]

Although useful to extract excitation energies of states of double-excitation character in time-dependent density functional theory that are missing in the adiabatic approximation, the frequency-dependent kernel derived earlier [Maitra et al., J. Chem. Phys. 120, 5932 (2004)] was not designed to yield oscillator strengths. These are required to fully determine linear absorption spectra, and they also impact excited-to-excited-state couplings that appear in dynamics simulations and other quadratic response properties. Here, we derive a modified non-adiabatic kernel that yields both accurate excitation energies and oscillator strengths for these states. We demonstrate its performance on a model two-electron system, the Be atom, and on excited-state transition dipoles in the LiH molecule at stretched bond-lengths, in all cases producing significant improvements over the traditional approximations. [ABSTRACT FROM AUTHOR]

We experimentally generate polarization spectroscopy (error) signals corresponding to the D2-line hyperfine transitions, F g = 2 → F e = 1 , 2 , 3 of 87Rb, and F g = 3 → F e = 2 , 3 , 4 of 85Rb, and show that the strongest error signals correspond to the closed hyperfine transitions (oscillator strength ∼ 0.7 ), F g = 2 → F e = 3 and F g = 3 → F e = 4 , respectively. We make the generated error signal robust to fluctuations in external parameters by finding optimum values for the vapor cell temperature and pump-probe intensities at two different beam diameters. We further employ these optimized error signals to directly (without the need for frequency/phase modulation) lock the laser frequency—reducing the rms drift/linewidth from ∼ 10 MHz to < 500 kHz, when measured over a ∼ 60 min duration. In addition, by comparing theoretically calculated and experimentally measured error signals for the pump intensities ranging from ∼ 0.1 I sat 0 − 10 I sat 0 (where, I sat 0 ∼ 1.6 mW cm−2 is the two-level saturation intensity for the Rb D2-line transitions), we discuss the applicability and limitations of existing numerical and analytical approaches based on a full multi-level rate equation model for polarization spectroscopy. [ABSTRACT FROM AUTHOR]

Organic light‐emitting diodes (OLEDs) employing multi‐resonance (MR) emitters have attracted much attention due to their high luminescent efficiency and color purity, however, the development of deep‐blue multi‐resonance OLEDs is hindered by the lack of suitable sensitizers. Here a novel design strategy is reported for thermally activated delayed fluorescence sensitizer with high reverse intersystem crossing (kRISC) and radiative transition (kR) rate by regulating atom distribution of a spatially‐aligned carbazole donor/diphenylpyrimidine acceptor structure to manipulate through‐space charge transfer (CT) process. It is found that diphenylpyrimidine acceptor with 1,3‐position nitrogen atoms is un‐conjugated to bridging phenyl moiety by the conjugation node of pyrimidine, while the acceptor with 1,5‐position nitrogen atoms is conjugated to bridging phenyl through conjugation site, opening through‐bond CT pathway via bridging phenyl besides through‐space CT from spatial donor‐acceptor interactions. As a result, the sensitizer with 1,5‐position nitrogen atoms exhibits enhanced oscillator strength by 3.5 folds and accelerated kR of 3.57 × 107 s−1, while keeping high kRISC of 4.03 × 106 s−1 and high singlet (S1) state (2.88 eV). Solution‐processed OLEDs using the sensitizer and deep‐blue multi‐resonance emitter exhibit efficient narrowband electroluminescence with CIE coordinates of (0.14, 0.13) and EQEmax of 15.6%, representing the state‐of‐the‐art device performance for deep‐blue multi‐resonance OLEDs by solution process. [ABSTRACT FROM AUTHOR]

The fundamental properties of an exciton are determined by the spin, valley, energy, and spatial wavefunctions of the Coulomb-bound electron and hole. In van der Waals materials, these attributes can be widely engineered through layer stacking configuration to create highly tunable interlayer excitons with static out-of-plane electric dipoles, at the expense of the strength of the oscillating in-plane dipole responsible for light-matter coupling. Here we show that interlayer excitons in bi- and tri-layer 2H-MoSe2 crystals exhibit electric-field-driven coupling with the ground (1s) and excited states (2s) of the intralayer A excitons. We demonstrate that the hybrid states of these distinct exciton species provide strong oscillator strength, large permanent dipoles (up to 0.73 ± 0.01 enm), high energy tunability (up to ~200 meV), and full control of the spin and valley characteristics such that the exciton g-factor can be manipulated over a large range (from −4 to +14). Further, we observe the bi- and tri-layer excited state (2s) interlayer excitons and their coupling with the intralayer excitons states (1s and 2s). Our results, in good agreement with a coupled oscillator model with spin (layer)-selectivity and beyond standard density functional theory calculations, promote multilayer 2H-MoSe2 as a highly tunable platform to explore exciton-exciton interactions with strong light-matter interactions. Here, the authors discover the ground and excited state interlayer excitons in bi- and tri-layer 2H-MoSe2 crystals which exhibit electric-field-driven hybridisation with the intralayer A excitons, showing distinct spin, layer and valley characteristics. [ABSTRACT FROM AUTHOR]

This study presents a simple model within the effective mass approximation to describe the effect of an external electric field on the energy structure and wave functions of quasiparticles in type II hemispherical quantum dots. The case of an electric field perpendicular to the base of a hemispherical quantum dot is considered. The solutions of the Schrödinger equation were obtained by two methods: finite element method and the matrix method. The last method allowed to determine the partial contribution of the basic states in the new states of quasiparticles obtained as a result of the action of an electric field. [ABSTRACT FROM AUTHOR]

Microorganisms produce siderophores, which are secondary metabolites with a high affinity for iron. Siderophores have received significant attention due to their diverse applications in ecological and clinical research. In this study, siderophores production by Escherichia coli OQ866153 was optimized using two-stage statistical approach involving Plackett–Burman design (PBD) and response surface methodology (RSM) using central composite design (CCD). Out of 23 variables, succinate, tryptophan, Na2HPO4, CaCl2, agitation, and KH2PO4 were found to have the most significant effect on siderophores production in the first optimization stage with the highest SU% of 43.67%. In the second stage, RSM using CCD was utilized, and the optimal conditions were determined to be 0.3 g/l succinate, 0 g/l tryptophan, 6 g/l Na2HPO4, 0.1 g/l CaCl2, 150 RPM agitation, and 0.6 g/l KH2PO4, resulting in a maximum siderophore units (SU%) of 89.13%. The model was significant, as indicated by the model f-value of 314.14 (p-value = 0.0004) and coefficient of determination R2 of 0.9950. During validation experiments, the obtained maximum SU% was increased up to 87.1472%, which was two times as the value obtained under ordinary conditions (46.62%). The produced siderophores were purified and characterized using 1H, 13C NMR, IR spectroscopy. The obtained results indicated that the compound was enterobactin and entABCDEF genes were further detected in Escherichia coli OQ866153 extracted DNA. To our knowledge, this is the first report of statistical optimization for enterobactin synthesis by an E. coli strain isolated from a clinical source in Egypt. [ABSTRACT FROM AUTHOR]

Cardamom (Elettaria cardamomum (L.) Maton) plays a crucial role in Guatemala's agriculture, supporting local families and covering 169,429.29 ha (making it the world's leading producer). Since its introduction to Guatemala in 1910, limited research has focused on unraveling the diversity and defining morphological traits critical for selecting excellent accessions. In this study, we examined 17 morphological traits across 288 accessions to identify key features associated with the germplasm. The comprehensive analysis employed principal component analysis, a morphological composite value (F-value), linear regression, and hierarchical clustering. The Shannon–Wiener diversity index ranged from 0.10 to 2.02, indicating the variation in diversity among traits. Principal component analysis and hierarchical clustering revealed six distinct germplasm groups. The comprehensive analysis facilitated the selection of 14 excellent accessions, and the regression equation incorporating criteria such as plant height, capsule color, panicle number per plant, panicle length, rhizome color, cluster number per panicle, cluster node length, and capsule number per cluster to identify cardamom germplasm. To develop a conservation strategy for the two putative foreign varieties ('Malabar' and 'Mysore'/'Vazhukka') introduced in Guatemala based on plant height, another 12 accessions were selected with a second comprehensive evaluation. This information offers insights into cardamom diversity for informed selection enhancing national utilization, productivity, and conservation. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) material-based nanocomposites are fascinating for the development of ultrathin optoelectronic devices with superior efficiency. Here, we report the ultra-violet (UV) photodetection characteristics of nanocomposite made of Au-decorated 2D graphitic carbon nitride (g-C3N4)-coated ZnO nanorods. The Au nanoparticles (NPs) have been developed on g-C3N4 nanosheets using the simple chemical route, while the nanocomposite with ZnO nanorods has been obtained using a cost-effective hydrothermal method. The 2D nature has been visualized through atomic force microscopy (AFM), while the existence of Au NPs has been confirmed from the plasmonic peak in absorption spectroscopy. The coating of ZnO nanorods with the net-like sheet has been observed in field emission scanning electron microscopy (FESEM). The as-synthesized nanocomposite has been found to be efficient for UV detection due to the presence of Au NPs. The type II heterojunction formed at the g-C3N4/ZnO interface facilitates charge transfer during UV illumination, while the Au NPs help to concentrate the UV radiation by increasing the oscillator strength of the system. [ABSTRACT FROM AUTHOR]

The photophysical and photochemical properties of the sulfonyl azide‐based fluorescent probe DNS–Az and its reduction product DNS by hydrogen sulfide (H2S) have been investigated theoretically. The calculated results indicated the first excited states of DNS–Az was dark state (oscillator strength less than 0.03) and DNS was bright state (oscillator strength more than 0.1), which determined the predicted radiative rate kr of DNS–Az was much smaller than that of DNS, meanwhile, due to more larger reorganization energy of DNS–Az, its predicted internal conversion rate kic was four times larger than that of DNS; moreover, owing to the effect of heavy atom from sulfur atom in DNS–Az, its predicted intersystem crossing rate kisc was seven times larger than that of DNS, thus the calculated fluorescence quantum yield of DNS–Az was only 2.16% and that of DNS was more than 77.2%, the above factors is the basis for DNS–Az molecule to function as a fluorescent probe. Regarding both DNS‐Az and DNS molecules, their maximum Huang‐Rhys factors, which are less than unity, signify the reliability of 0–0 transitions between their S0 and S1 electronic states. In addition, for DNS, our simulated emission peak of the 0–0 transition is 515 nm, a value that exhibits enhanced accuracy and coherence when compared to the experimental datum of 528 nm. The reaction mechanism of DNS‐Az generating DNS by H2S has been investigated too, according to the potential energy profile, we found that the fluorescent probe firstly protonated, then this organic ion broke down into DNS with the aid of a proton. [ABSTRACT FROM AUTHOR]

The development of high‐efficiency near‐infrared (NIR) organic emitters has been severely constrained by strong and unavoidable non‐radiative decay governed by the “energy gap law”, which leads to low emission efficiencies and limited options for molecular design. Herein, comparative studies are performed on six‐ and five‐membered π‐bridge and a novel benzo[b]thiophene‐based donor is designed through elaborate molecular engineering, which outperforms widely‐used triphenylamine derivatives in constructing NIR thermally activated delayed fluorescence emitters. The benzo[b]thiophene donor/π‐bridge endows the newly synthesized molecule tBTAP with multiple advantages, including longer emission wavelength and enhanced oscillator strength compared with thiophene‐free triphenylamine donor, and suppressed high‐frequency vibrations compared with thiophene‐inserted donor. Consequently, tBTAP doped and nondoped films display pure NIR emission at peak wavelengths of 795 nm and 854 nm with state‐of‐the‐art photoluminescence quantum yields of 17.9 ± 0.3% and 4.6 ± 0.4%. The corresponding NIR OLEDs demonstrate record‐high maximum external quantum efficiencies of 3.64% (796 nm) and 1.20% (867 nm). Most importantly, nondoped device exhibits record‐long operational lifetime (LT97) of over 2150 h at 10 mA cm−2 for NIR OLEDs. This study signifies an advance in molecular engineering by designing alternative donor/π‐bridge structure, breaking through the bottleneck in developing high‐performance NIR organic emitters and devices toward practical applications. [ABSTRACT FROM AUTHOR]

The crystal 1H-imidazole-1-methanol (HIM) was thoroughly investigated using density functional theory (DFT) to optimize its vibrational, natural bonding orbital (NBO), geometrical, Hirshfeld surface analysis properties, as well as electronic, linear, and nonlinear optical properties. Geometrical parameters and vibrational frequencies were obtained from the B3LYP/6–311++G(d,p) level of theory, and the obtained values for the geometrical parameters were found to be in good agreement with experimental values. The potential energy distribution (PED) for the vibrational FT-IR frequencies was compared to experimental results. Additionally, a time-dependent DFT approach was used to determine the excitation energies, oscillator strengths, and UV–Vis spectra of water, dimethyl sulfoxide (DMSO), and gas. The NBO analysis of the compound involved analyzing atom hybridization and electronic structure. Reactivity of the molecule was studied using the Molecular Electrostatic Potential (MEP), Fukui function, and Local Reactivity Descriptors. Furthermore, calculations were performed to determine the molecular nonlinear optical (NLO) characteristics, including static dipole moment, polarizability, and first-order hyperpolarizability. The compound's multiwave functions, such as the localized orbital locator (LOL) and electron localization function (ELF), were also determined. Finally, Hirshfeld surface analysis was conducted to investigate the interactions within and between molecules of the title compound. [ABSTRACT FROM AUTHOR]

The radiative opacity of Sn plasmas plays a crucial role in the investigation of extreme ultraviolet (EUV) lithography. In this study, a complete atomic database of Sn4+–Sn18+ is established, and the spectrally resolved and mean opacities are investigated using a detailed-level accounting model. The energy levels and oscillator strengths are obtained in the multiconfiguration Dirac–Hartree–Fock framework. Large-scale configuration interaction calculations are performed in which the number of fine structure levels is on the order of 2 × 105 for each ionization stage. The electron correlation effects are considered to obtain accurate transition data in EUV regions. The photoionization cross sections are calculated using the distorted wave method. The spectrally resolved radiative opacities at temperatures of 5–40 eV and densities of 0.0001–1.0 g/cm3 are investigated. The spectral characteristics are demonstrated with variable temperatures and densities. The main contribution to absorption lines in the EUV region arises from Sn10+ and nearby ions, and the optimized temperatures and densities producing Sn10+ are presented. The Planck and Rosseland mean opacities are given at variable temperatures and densities, which is helpful for radiation hydrodynamic simulations of laser–Sn interactions. [ABSTRACT FROM AUTHOR]

The two-dimensional (2D) hydrogen atom is a fundamental atomic model that is important for various technologies based on 2D materials. Here, the atomic model is revisited to enhance understanding of the hydrogen wavefunctions. Unlike in previous studies, we propose an alternative expression of azimuthal wavefunctions, which are the eigenstates of the square of angular momentum and exhibit rotational symmetry. Remarkably, our expression leads to the rotation and oscillation along the azimuthal direction of the probability densities, which do not appear in the conventional wavefunctions. These behaviors are validated by the numerical results obtained through the 2D finite difference approach. Variation in oscillator strengths due to the rotation of wavefunctions is observed in our proposed 2D hydrogen wavefunctions, whereas those due to the conventional wavefunctions remain constant. More importantly, the proposed wavefunctions' advantage is illustrating the orbital shapes of the planar hydrogen states, whose orientation is labeled here using Cartesian representation for the first time. This study can be applied to visualize the orbital characteristics of the states in quantum confinement with a radial potential. [ABSTRACT FROM AUTHOR]

The adsorption and fluorescence spectra of the grown Nd∶GdYAG were measured. The spectral parameters, such as oscillator strength, line strength, intensity parameter Ωt, transition probability between 4 F3/2→4 IJ levels, radiation lifetime, and fluorescence branching ratio, were calculated with Judd-Ofelt theory. The calculated Ωt are Ω2 = (0.813 ±0.200) ×10-20 cm2, Ω4 = (3. 381 ±0. 187) × 10 -20 cm2, Ω6 = (5. 135 ± 0. 278) × 10 -20 cm2, respectively. Compared with Nd-doped YAG, LuAG, YVO4, and other crystals, Nd∶GdYAG crystal has a larger Ω2, showing that the addition of Gd3 + increases the disorder of the host. The absorption cross-section and refractive index in the range of 300 ~1 200 nm were calculated and fitted. The absorption cross-section at 808 nm is 5. 0 ×10 -20 cm2. The refractive index at 1 064 nm is 1. 80. The measured fluorescence lifetime of 4 F3/2 level is 228 μs, which is close to the calculated radiation lifetime of 240 μs. The emission cross-section at 1 064 nm is 1. 23 × 10 -19 cm2, which is close to that of Nd∶ YAG crystal. Addition, at room temperature, the thermal conductivity of Nd∶GdYAG crystal is 5. 992 W/(m·K), which is slightly smaller than that of Nd∶YAG and Nd∶GGG, but larger than that of Nd∶YVO4 crystal. The results show that Nd∶GdYAG is a promising new laser crystal material. [ABSTRACT FROM AUTHOR]

Tetrachlorodiethyl Benzimidazo Carbocyanine (TDBC) layers are very interesting for photonics applications due to their huge oscillator strength, narrow absorption and low-cost fabrication. They are mainly used in strong coupling studies but also for wavelength selective grating fabrication, light concentration, absorption enhancement and so on. However, these intrinsic properties, particularly the refractive index, require further investigation. In this work, we first reviewed the values of the refractive index of TDBC layers reported in the literature. Using fitting with the Drude–Lorentz model, differences are highlighted. We then fabricated pure TDBC layers and measured their properties using ellipsometry and absorption spectroscopy. Finally, we also evaluated the refractive index as a function of the layer bleaching. This work shows that although the precise refractive index evaluation of pure TDBC layers is dependent on the measurement method, their oscillator strength force still remains very high without bleaching. [ABSTRACT FROM AUTHOR]

This paper proposes a multiplexing multi-scale features network (MMF-Network) for salient target detection to tackle the issue of incomplete detection structures when identifying salient targets across different scales. The network, based on encoder–decoder architecture, integrates a multi-scale aggregation module and a multi-scale visual interaction module. Initially, a multi-scale aggregation module is constructed, which, despite potentially introducing a small amount of noise, significantly enhances the high-level semantic and geometric information of features. Subsequently, SimAM is employed to emphasize feature information, thereby highlighting the significant target. A multi-scale visual interaction module is designed to enable compatibility between low-resolution and high-resolution feature maps, with dilated convolutions utilized to expand the receptive field of high-resolution feature maps. Finally, the proposed MMF-Network is tested on three datasets: DUTS-Te, HUK-IS, and PSCAL-S, achieving scores of 0.887, 0.811, and 0.031 in terms of its F-value SSIM and MA, respectively. The experimental results demonstrate that the MMF-Network exhibits a superior performance in salient target detection. [ABSTRACT FROM AUTHOR]

Electrical modulation of luminescence is significant to modern light-emitting devices. Monolayer transition metal dichalcogenides are emerging direct-bandgap luminescent materials with unique excitonic properties, and the multiple exciton complexes provide new opportunities to modulate the property of luminescence in atomically thin semiconductors. Here, we report an electrical control of exciton emission in the oscillator strength and spatial distribution of excitons in a monolayer WS2. Effective modulation of excitonic emission intensity with a degree of modulation of ~ 92% has been demonstrated by an electric field at room temperature. The spatial carrier redistribution tuned by a lateral electric field results in distinct excitonic emission patterns by design. The modulation approach to exciton oscillator strength and distribution provides an efficient way to investigate the exciton diffusion dynamics and to construct electrically tunable optoelectronic devices. [ABSTRACT FROM AUTHOR]

Simulations of laser-induced electron dynamics in a molecular system are performed using time-dependent (TD) equation-of-motion (EOM) coupled-cluster (CC) theory. The target system has been chosen to highlight potential shortcomings of truncated TD-EOM-CC methods [represented in this work by TD-EOM-CC with single and double excitations (TD-EOM-CCSD)], where unphysical spectroscopic features can emerge. Specifically, we explore driven resonant electronic excitations in magnesium fluoride in the proximity of an avoided crossing. Near the avoided crossing, the CCSD similarity-transformed Hamiltonian is defective, meaning that it has complex eigenvalues, and oscillator strengths may take on negative values. When an external field is applied to drive transitions to states exhibiting these traits, unphysical dynamics are observed. For example, the stationary states that make up the time-dependent state acquire populations that can be negative, exceed one, or even complex-valued. [ABSTRACT FROM AUTHOR]

The intermediate state representation (ISR) formalism allows for the straightforward calculation of excited state properties and state-to-state transition moments using the algebraic-diagrammatic construction (ADC) scheme for the polarization propagator. Here, the derivation and implementation of the ISR in third-order perturbation theory for the one-particle operator are presented, enabling, for the first time, the calculation of consistent third-order ADC [ADC(3)] properties. The accuracy of ADC(3) properties is evaluated with respect to high-level reference data and compared to the previously used ADC(2) and ADC(3/2) schemes. Oscillator strengths and excited state dipole moments are computed, and typical response properties are considered: dipole polarizabilities, first-order hyperpolarizabilities, and two-photon absorption strengths. The consistent third-order treatment of the ISR leads to an accuracy similar to that of the mixed-order ADC(3/2) method; the individual performance, however, depends on the property and molecule under investigation. ADC(3) produces slightly improved results in the case of oscillator strengths and two-photon absorption strengths, while excited state dipole moments, dipole polarizabilities, and first-order hyperpolarizabilities exhibit similar accuracy at ADC(3) and ADC(3/2) levels. Taking the significant increase of central processing unit time and memory requirements of the consistent ADC(3) approach into account, the mixed-order ADC(3/2) scheme offers a better compromise between accuracy and efficiency for the properties considered. [ABSTRACT FROM AUTHOR]

In highly doped semiconductor quantum wells (QWs), electrons populate various energy states from different subbands and, therefore, several optical intersubband transitions (ISBTs) can occur simultaneously. Coulomb coupling between these ISBTs gathers the strength of all the individual transitions and concentrates all the oscillator strength in a single collective excitation: the multisubband plasmon (MSP). MSPs are an excellent platform for the study of collective and exotic effects in semiconductors and for the demonstration of novel device concepts. Indeed, the high electronic densities involved in the collective excitation greatly enhance the coupling strength and enable the ultra-strong coupling regime between MSPs and either optical modes in a cavity or phonons in the semiconductor. In this Perspectives paper, after addressing the basic physics of MSPs and the state of the art, we outline the most promising paths for the research community in this topic from the point of view of basic physics, material platforms, and applications of MSPs. [ABSTRACT FROM AUTHOR]

Multiconfiguration Dirac–Hartree–Fock (MCDHF) calculations of energy levels, oscillator strengths and transition rates of open K-shell transitions in beryllium-like tungsten ion, W 7 0 + , are performed using the fully relativistic GRASP2018 code. For only principal quantum number n = 2 , energy levels of 1 s 2 2 s 2 , 1 s 2 2 s 2 p , 1 s 2 2 p 2 , 1 s 2 s 2 2p, 1 s 2 p 3 and 1 s 2 s 2 p 2 at different angular momenta and parity ( J P) are presented. Excitations of up to four electrons from the ground level, 1 s 2 2 s 2 , to excited levels are allowed. Correlations up to 5l orbitals are included in the configuration state function (CSF), l = s , p, d, f and g. The fine-structure calculations of E1, E2, M1 and M2 oscillator strengths and radiative rates between intercombination transitions in W 7 0 + ions are evaluated. The accuracy of these results is estimated using different ways, such as the comparison with previously published results and calculating the uncertainty of the transition data. The uncertainty of the transition probabilities showed low values for most of transitions. [ABSTRACT FROM AUTHOR]

Intervalley excitons with electron and hole wavefunctions residing in different valleys determine the long-range transport and dynamics observed in many semiconductors. However, these excitons with vanishing oscillator strength do not directly couple to light and, hence, remain largely unstudied. Here, we develop a simple nanomechanical technique to control the energy hierarchy of valleys via their contrasting response to mechanical strain. We use our technique to discover previously inaccessible intervalley excitons associated with K, Γ, or Q valleys in prototypical 2D semiconductors WSe2 and WS2. We also demonstrate a new brightening mechanism, rendering an otherwise "dark" intervalley exciton visible via strain-controlled hybridization with an intravalley exciton. Moreover, we classify various localized excitons from their distinct strain response and achieve large tuning of their energy. Overall, our valley engineering approach establishes a new way to identify intervalley excitons and control their interactions in a diverse class of 2D systems. The authors develop a nanomechanical straining technique to reveal previously inaccessible intervalley excitons in suspended WSe2 and WS2. They further unveil a mechanism that brightens the dark intervalley excitons through strain-controlled hybridization with intravalley excitons. [ABSTRACT FROM AUTHOR]

Newly-developed spectrographs with increased resolving powers, particularly those covering the near-IR range, allow the characterization of more and more absorption lines in stellar spectra. This includes the identification and confirmation of absorption lines and the calibration of oscillator strengths. In this study, we provide empirical values of |${{\rm log} gf}$| based on the abundances of classical Cepheids obtained with optical spectra to establish the consistency between optical and infrared abundance results. Using time series spectra of classical Cepheids obtained with WINERED spectrograph (0.97–1.35  |$\mu$| m, R |$\sim$| 28000), we demonstrate that we can determine the stellar parameters of the observed Cepheids, including effective temperature (⁠|${T_\mathrm{eff}}$|⁠), surface gravity (⁠|${{\rm log} g}$|⁠), microturbulence (⁠|$\xi$|⁠), and metallicity (⁠|${\rm {[{\mathrm{ M}}/\mathrm{ H}]}}$|⁠). With the newly calibrated relations of line-depth ratios, we can achieve accuracy and precision comparable to optical studies, with uncertainties of |$\sim$| 90 K and 0.108 dex for |${T_\mathrm{eff}}$|⁠ , and |${{\rm log} g}$|⁠ , respectively. Finally, we created a new atlas of absorption lines, featuring precise abundance measurements of various elements found in the atmosphere of Cepheids, including neutron-capture elements whose |${{\rm log} gf}$| values have been astrophysically calibrated. [ABSTRACT FROM AUTHOR]

The present work explored the electrochemical behavior of two organic compounds, o‐hydroxybenzylidene‐orthochloroaniline(Anil‐1) and o‐hydroxynaphthalidene‐orthochloro aniline(Anil‐2) through a series of theoretical and experimental investigations. The vibrational frequencies of two anilswere analyzed experimentally by FTIR and theoretically by DFT studies. A comparison of the frequencies with their unsubstituted analog, o‐hydroxybenzylideneaniline, confirmed the electron‐donating nature of the −Cl and −OH substituents in anils. The hyperconjugative interaction energy obtained from NBO analysis divulged the direction of the electron donation from the donor orbitals to the acceptor orbitals. UV‐visible studies illustrated prominent π→π* electronic transitions with significant oscillator strength(0.10–0.26) and molar extinction coefficient(~104) experimentally. Analysis of the global and local reactive descriptors of anils revealed a lower HOMO‐LUMO energy gap of Anil‐2(4.05 eV) than Anil‐1(4.46 eV), corroborating the order of decreasing reactivity to be Anil‐2>Anil‐1. The Cyclic Voltammetry studies disclosed the involvement of an oxidation process in Anil‐1 and Anil‐2 with a higher oxidation potential of Anil‐1 (1.43 V) than Anil‐2(1.31 V) due to the naphthyl moiety of the latter. However, the absence of a cathodic peak in both cases envisaged the irreversible nature of oxidation. The results demonstrated that both the anils could be suitable optical materials for microelectronics applications. [ABSTRACT FROM AUTHOR]

The advancement of deep‐blue luminophores with high efficiency, color purity, and stable characteristics remains hindered by the absence of effective molecular design methodologies. Herein, a proof‐of‐concept deep blue hot exciton emitter, namely 2ANAC is designed and synthesized, featuring a rod‐like, symmetric π‐donor‐σ‐donor‐π (π‐D‐σ‐D‐π) molecular architecture to address the above challenges. The symmetric molecular structure endows numerous degenerate excited state characteristics, facilitating intersystem crossing between energy closely singlet and triplet states. Owing to nearly perpendicular conformation between the D‐π moieties, the formed low‐lying singlet excited (S1 to S4) states exhibit minimal oscillator strengths. In contrast, the fifth singlet excited (S5) state boasts a significantly higher oscillator strength. This indicates the potential for anti‐Kasha emission behavior, thus promoting the highly emissive deep‐blue luminescence from the locally excited state with a relatively small full width at half maximum. Furthermore, the long‐axial molecular architecture confers as high as 90% of the horizontal dipole ratio. The corresponding non‐doped deep‐blue OLED based on 2ANAC exhibits an outstanding maximum external quantum efficiency of 10.8% with minimal efficiency roll‐off, representing one of the highest reported values for deep‐blue hot exciton OLEDs. [ABSTRACT FROM AUTHOR]

Multi‐resonant thermally activated delayed fluorescent (MR‐TADF) materials, which combine large oscillator strengths, small singlet‐triplet energy gaps, high photoluminescence quantum yields, and color purity, have attracted great interest in both experimental and theoretical research in recent years. However, the differences between two classes of MR‐TADF, utilizing carbonyl groups and boron atoms as acceptors respectively, have not been clearly delineated, and the implementation of strategies combining both is extremely limited. This limitation hampers the diversity in composition and structure of MR‐TADF. In this study, we employed boron as the central acceptor and carbonyl groups as peripheral acceptors, designing and investigating 7 merged systems of MR‐TADF molecules. Calculations revealed that, in contrast to the strong acceptor characteristics of boron atoms, carbonyl groups do not exhibit absolute acceptor features, and their resonance effects depend on the surrounding environment. This unique resonance effect induces LRCT features to varying degrees, enabling the emission coverage of these molecules across almost the entire visible spectrum (theoretical emission wavelengths covering 452–751 nm). We gained an understanding of the differences between boron acceptors and carbonyl groups, achieving full‐color emission by adjusting only the MR cores. This provides insights into the rational design of complex‐component full‐color MR‐TADF emitters. [ABSTRACT FROM AUTHOR]

Single-isotherm n(p, T90) results are reported for the gases Ar, N2, H2O, and D2O at vacuum wavelength λ = 1542.383 (1) nm. The argon and nitrogen isotherms were measured near 303 K; the water isotherms were measured near 373 K. Combined with the two previous articles of this series, the present results beget several insights via dispersion analyses. The argon result is highly consistent with static measurement plus ab initio calculation of dispersion polarizability. The nitrogen result is nominally consistent with one recent experiment and the dipole oscillator strength distributions, but the present work offers a refined estimate of the molar refractivity at optical wavelengths. For ordinary and heavy water, the dispersion trend is nominally consistent with existing liquid measurements. However, water's absorption features in the near-infrared preclude a reliable comparison of the present result with literature. [ABSTRACT FROM AUTHOR]

This research paper figures out thermal performance analysis for vapor compression refrigeration (VCR) driven by the organic Rankine cycle (ORC) implementing MATLAB software. The ORC system is powered by improved evacuated tubes and compound parabolic collectors. The paper evaluates the overall exergetic efficiency and coefficient of performance using the working fluid Pentane/R245fa. The result of the present paper indicates that optimum COP of 0.75 and exergetic efficiency of 28% is obtained at 340 K of collector output temperatures, 0.1/0.9 of fractional mass of the working fluid, and 285, 300 K for VCR condenser and evaporator temperature, respectively. Sensitivity analysis pointed out that condenser temperature was the most impactful parameter for both exergetic efficiency and COP owing to higher F-value 'of 156.06' and '89.28,' respectively. Further, collector output temperature and fractional mass of the working fluid were the least impactful parameters owing to lower F-value '1.95' and '1.02' for exergetic efficiency and COP, respectively. [ABSTRACT FROM AUTHOR]

We study and describe the reshaping of ultrashort and broadband mid-IR optical pulses in an ambient atmosphere. While all pulse propagation undergoes dispersion and absorption, which causes pulse reshaping, the effects are strongly pronounced for broadband radiation in the mid-IR due to the orders of magnitude greater oscillator strengths of molecular constituents of our atmosphere. A noticeable macroscopic impact is a transition of the measured autocorrelation function from squared hyperbolic secant to Lorentzian, which we fully explain based on pulse propagation, including molecular free induction decay. Electro-optical sampling directly reveals the light wave response to atmospheric molecular free induction decay, and a Kramers–Kronig-based propagation model thoroughly explains the observation. The findings are essential for applications in sensing, standoff detection, high-energy pulse propagation, and energy delivery. [ABSTRACT FROM AUTHOR]

We introduce a method for detecting humans in thermal imaging using an end-to-end deep learning model. Our objective is to optimize the human detection process in thermal imaging by investigating the mask region-based convolutional neural network (Mask R-CNN). The model, an advancement of the faster region-based convolutional neural network (Faster R-CNN), not only captures bounding boxes encompassing human subjects but also delineates segmentation masks around them. Our investigation extends to the evaluation and comparison of various convolutional neural networks for feature learning, like residual network (ResNet) and Inception ResNet, all integrated into the Mask R-CNN framework. Furthermore, the experimental results show that our proposed technique achieves high accuracy. Specifically, the Mask R-CNN model using ResNet50-V1 achieved the best results, with an F-value of 87.85%, a recall of 79.33%, and a precision of 98.41%. [ABSTRACT FROM AUTHOR]

Aims. It is now well established that a large amount of heavy (trans-iron) elements are produced during neutron star (NS) mergers. These elements can be detected in the spectra of the kilonova emitted from the post-merger ejected materials. Due to the high level densities that characterize the complex configurations belonging to heavy elements, thus giving rise to millions of absorption lines, the kilonova ejecta opacity is of significant importance. The elements that contribute the most to the latter are those with an unfilled nd subshell belonging to the fifth and the sixth rows of the periodic table, and those with an unfilled nf subshell belonging to the lanthanide and actinide groups. The aim of the present work is to make a new contribution to this field by performing large-scale atomic structure calculations in three specific sixth-row 5d elements, namely hafnium, osmium, and gold, in the first four charge stages (I–IV), and by computing the corresponding opacities, while focusing on the importance of the atomic models used. Methods. The pseudo-relativistic Hartree–Fock (HFR) method, including extended sets of interacting configurations, was used for the atomic structure and radiative parameter calculations, while the expansion formalism was used to estimate the opacities. Results. Theoretical energy levels, wavelengths, and oscillator strengths were computed for millions of spectral lines in Hf I–IV, Os I–IV, and Au I–IV ions, the reliability of these parameters being assessed through detailed comparisons with previously published experimental and theoretical results. The newly obtained atomic data were then used to calculate expansion opacities for typical kilonova conditions expected one day after the NS merger; these are a density of ρ = 10−13 g cm−3 and temperatures ranging from T = 5000 K to T = 15 000 K. Some agreements and differences were found when comparing our results with available data, highlighting the importance of using sufficiently complete atomic models for the determination of opacities. [ABSTRACT FROM AUTHOR]

Exciton–polaritons, which are bosonic quasiparticles with an extremely low mass, play a key role in understanding macroscopic quantum effects related to Bose–Einstein condensation (BEC) in solid-state systems. The study of trapped polaritons in a potential well provides an ideal platform for manipulating polariton condensates, enabling polariton lasing with specific formation in k-space. Here, we realize quantized microcavity polariton lasing in simple harmonic oscillator (SHO) states based on spatial localized excitons in InGaN/GaN quantum wells (QWs). Benefiting from the high exciton binding energy (90 meV) and large oscillator strength of the localized exciton, room-temperature (RT) polaritons with large Rabi splitting (61 meV) are obtained in a strongly coupled microcavity. The manipulation of polariton condensates is performed through a parabolic potential well created by optical pump control. Under the confinement situation, trapped polaritons are controlled to be distributed in the selected quantized energy sublevels of the SHO state. The maximum energy spacing of 11.3 meV is observed in the SHO sublevels, indicating the robust polariton trapping of the parabolic potential well. Coherent quantized polariton lasing is achieved in the ground state of the SHO state and the coherence property of the lasing is analyzed through the measurements of spatial interference patterns and g(2)(τ). Our results offer a feasible route to explore the manipulation of macroscopic quantum coherent states and to fabricate novel polariton devices towards room-temperature operations. [ABSTRACT FROM AUTHOR]

Materials with significant first hyperpolarizability values are essential for application in second harmonic generation to achieve frequency doubling. Therefore, ideal NLO materials must not only exhibit a substantial NLO response but also maintain transparency when exposed to laser light. In this study, we investigate two series of nanoparticles, namely M@b64Al12N12 and M@b66Al12N12 (M ranges from Sc to Zn). The aim is to evaluate the second and third NLO responses through DFT and TD-DFT calculations. These evaluations are performed using the CAM-B3LYP/6-311+G(d) level of theory and the sum-over-states method in the static and dynamic regime (λ = ∞, 1906, 1341, and 1064 nm). These properties are further explained by considering factors such as molecular topology, delocalization indices, Waber–Cromer radius, excitation energy, oscillator strengths, variations of dipole moment of the excited state, and one/two-photon resonance effects. The results indicate that incorporating transition metals into Al12N12 substantially increases both the first and second hyperpolarizability. The delocalization index values reveal a higher degree of electron delocalization between the transition metal and nitrogen compared to that between the transition metal and aluminum. The QTAIM analysis displays that the presence of a closed quasi-ring structure between the metal and the nanocage, combined with electron delocalization, significantly enhances the first hyperpolarizability. TD-DFT calculations suggest potential application of these compounds in deep ultraviolet laser devices due to their transparency below 200 nm. The SOS approach reveals that the most critical excited states are local excitations, characterized by high Sr, small D, and negative t values. On the other hand, in the dynamic regime, our results indicated that the values of βHRS, βSHG(−2ω; ω, ω) and γESHG(−2ω; ω, ω, 0) are larger than their static counterparts. Additionally, one/two photon resonance energy, along with substantial oscillator strength, plays a pivotal role in enhancing the dynamic hyperpolarizability of the investigated nanoparticles. Our findings suggest that the increase in βλ is primarily linked to two-photon resonance rather than one-photon resonance. Based on our current understanding, this study provides novel evidence that, at λ = ∞, the first hyperpolarizability of M@b64/66Al12N12 is correlated with the Waber–Cromer radius of the transition metal. Additionally, in the dynamic regime, the first hyperpolarizability is correlated with the second hyperpolarizability. [ABSTRACT FROM AUTHOR]

The Psoralen (Pso) molecule finds extensive applications in photo‐chemotherapy, courtesy of its triplet state forming ability. Sulfur and selenium replacement of exocyclic carbonyl oxygen of organic chromophores foster efficient triplet harvesting with near unity triplet quantum yield. These triplet‐forming photosensitizers are useful in Photodynamic Therapy (PDT) applications for selective apoptosis of cancer cells. In this work, we have critically assessed the effect of the sulfur and selenium substitution at the exocyclic carbonyl (TPso and SePso, respectively) and endocyclic oxygen positions of Psoralen. It resulted in a significant redshifted absorption spectrum to access the PDT therapeutic window with increased oscillator strength. The reduction in singlet‐triplet energy gap and enhancement in the spin‐orbit coupling values increase the number of intersystem crossing (ISC) pathways to the triplet manifold, which shortens the ISC lifetime from 10−5 s for Pso to 10−8 s for TPso and 10−9 s for SePso. The intramolecular photo‐induced electron transfer process, a competitive pathway to ISC, is also considerably curbed by exocyclic functionalizations. In addition, a maximum of 115 GM of two‐photon absorption (2PA) with IR absorption (660–1050 nm) confirms that the Psoralen skeleton can be effectively tweaked via single chalcogen atom replacement to design a suitable PDT photosensitizer. [ABSTRACT FROM AUTHOR]

This study analyzes the influence of stakeholder decision-making strategies and policies on PT's investment performance. PLN (Persero), is Indonesia's state-owned electricity company. Indonesia has a geothermal potential of 28 GWe and aims to add 3.3 GW of installed capacity by 2030. Our analysis reveals that effective stakeholder decision-making and well-formulated policies significantly enhance investment performance. This is supported by statistical evidence, with both the t-test and F-test results showing significance (calculated t-value and F-value exceed their respective critical values, with p-values < 0.05). Enhancing these strategies and policies is crucial for meeting Indonesia's new renewable energy (NRE) targets as outlined in the 2021-2030 RUPTL. [ABSTRACT FROM AUTHOR]

This study aims to determine the influence of performance appraisal and core values of AKHLAK on work performance. The researcher employed a quantitative method with a descriptive causal approach. The population in this study consisted of the permanent employees of PT. Telkom Witel Sukabumi, totaling 32 employees, with the sample size also being 32 permanent employees of PT. Telkom Witel Sukabumi. The results of this study indicate that performance appraisal has a significant influence on employee work performance at PT. Telkom Witel Sukabumi, with a t-value of 8.482, which is greater than the t-table value of 1.695, and a significance level of 0.000 < 0.05. Meanwhile, the core values of AKHLAK do not have a significant influence on work performance, with a t-value of -0.982, which is smaller than the t-table value of 1.695, and a significance level of 0.334 > 0.05. The F-test shows that both independent variables simultaneously have a significant influence on work performance, with an F-value of 35.990, which is greater than the F-table value of 3.33, and a significance level of 0.000 < 0.05. Descriptive analysis indicates that respondents' responses to performance appraisal and the core values of AKHLAK fall into the very high category. The proper implementation of performance appraisal is proven to enhance work performance, while the core values of AKHLAK require further approaches to have a significant impact. [ABSTRACT FROM AUTHOR]

Iron is the dominant heavy element that plays an important role in radiation transport in stellar interiors. Owing to its abundance and large number of bound levels and transitions, iron ions determine the opacity more than any other astrophysically abundant element. A few iron ions constitute the abundance and opacity of iron at the base of the convection zone (BCZ) at the boundary between the solar convection and radiative zones and are the focus of the present study. Together, Fe xvii, Fe xviii and Fe xix represent 85% of iron ion fractions, 20%, 39% and 26% respectively, at the BCZ physical conditions of temperature T ∼ 2.11 × 10 6 K and electron density N e = 3.1 × 10 22 c.c. We report the most extensive R -matrix atomic calculations for these ions for bound–bound and bound–free transitions, the two main processes of radiation absorption. We consider wavefunction expansions with 218 target or core ion fine structure levels of Fe xviii for Fe xvii, 276 levels of Fe xix for Fe xviii, in the Breit–Pauli R -matrix (BPRM) approximation, and 180 LS terms (equivalent to 415 fine structure levels) of Fe xx for Fe xix calculations. These large target expansions, which include core ion excitations to n = 2,3,4 complexes, enable accuracy and convergence of photoionization cross sections, as well as the inclusion of high lying resonances. The resulting R -matrix datasets include 454 bound levels for Fe xvii, 1,174 levels for Fe xviii, and 1,626 for Fe xix up to n ⩽ 10 and l = 0–9. Corresponding datasets of oscillator strengths for photoabsorption are: 20 951 transitions for Fe xvii, 141 869 for Fe xviii, and 289 291 for Fe xix. Photoionization cross sections have been obtained for all bound fine structure levels of Fe xvii and Fe xviii, and for 900 bound LS states of Fe xix. Selected results demonstrating prominent characteristic features of photoionization are presented, particularly the strong Seaton photoexcitation-of-core resonances formed via high-lying core excitations with Δ n = 1 that significantly impact bound–free opacity. [ABSTRACT FROM AUTHOR]

An extended version of the R -matrix methodology is presented for calculation of radiative parameters for improved plasma opacities. Contrast and comparisons with existing methods primarily relying on the distorted wave approximation are discussed to verify accuracy and resolve outstanding issues, particularly with reference to the opacity project (OP). Among the improvements incorporated are: (i) large-scale Breit–Pauli R -matrix calculations for complex atomic systems including fine structure, (ii) convergent close coupling wave function expansions for the (e + ion) system to compute oscillator strengths and photoionization cross sections, (iii) open and closed shell iron ions of interest in astrophysics and experiments, (iv) a treatment for plasma broadening of autoionizing resonances as function of energy-temperature-density dependent cross sections, (v) a 'top-up' procedure to compare convergence with R -matrix calculations for highly excited levels, and (vi) spectroscopic identification of resonances and bound (e + ion) levels. The present R -matrix monochromatic opacity spectra are fundamentally different from OP and lead to enhanced Rosseland and Planck mean opacities. An outline of the work reported in other papers in this series and those in progress is presented. Based on the present re-examination of the OP work, opacities of heavy elements might require revisions in high temperature-density plasma sources. [ABSTRACT FROM AUTHOR]

The sol-gel route is used to prepare samarium (Sm+3) ions doped in silica monoliths as a function of active ion concentrations up to 0.0178%. The spectroscopic activity of Sm+3 ions doped-silica matrices is investigated using UV-Visible spectroscopy and photoluminescence spectroscopy. 4G5/2 emissions are observed from a minority of isolated Sm+3 ions within the pores structure of silica matrix, UV-Vis spectra reveals absorption peaks due to Sm+3 active centers. X-ray diffraction and FTIR results support the distribution of such ions in these porous. Analysis indicates that at high doping levels, most ions reside in clusters and 4G5/2 emission, which is demonstrated by the quenching processes observed in the corresponding spectra. Some spectroscopic parameters such as emission cross-section and oscillator strength are determined and analyzed. [ABSTRACT FROM AUTHOR]

Trivalent erbium ions doped (48 – x) AlPO4 + 15K2O + 12MgF + 20Na2O + 5NaF + xEr2O3 glass samples have been prepared utilizing the melt-quench process and studied to understand the efficacy of Er3+ ions content on physical, structural and luminescence attributes of host glass. The functional groups of the glass structure such as metaphosphate, orthophosphate and pyrophosphate have been elucidated through Fourier Transform Infrared (FTIR) spectroscopic investigation. The least-square approach was used to calculate the Judd–Ofelt parameter from the oscillator strength of the Er3+ ion transitions. The luminescence emission data captured in the visible and near-infrared (NIR) province using 380 and 980 nm excitation wavelengths. The up-conversion (recorded at the excitation at 980 nm) of 0.5 Er glass exhibited emission at 664, 550 and 488 nm wavelengths. The decay plots of the studied glass specimens were measured at 980 nm excitation. The McCumber (MC) theory has been implemented to calculate the gain coefficient of the 0.5 Er glass and flat gain curve was drawn for S-band, C-band and L-band. The attributes for optical amplification were ascertained, including the quality factor (0.85), branching ratio (1), stimulated emission cross-section (1.3 × 10–20 cm2), gain bandwidth (1.26 × 10–25 cm3) and optical gain (0.394 × 10–23 cm2 s) for 0.5 Er glass. The yellowish green light emission ability of the 0.5 Er glass after 980 nm excitation evident through CIE co-ordinates position (x 0.36, y 0.58) at 1931 CIE chromaticity diagram. The spectroscopic and luminescence results endorse that the alumino–phosphate glass specimens loaded with 0.5 mol% of Er2O3 are beneficial for NIR and green light emission applications. [ABSTRACT FROM AUTHOR]

In this work, glass with composition (75- x)B 2 O 3 - x TeO 2 -11Bi 2 O 3 –10Li 2 O-1Ho 2 O 3 -3Yb 2 O 3 (x = 10–60 mol%) were synthesized using the melt quenching technique to investigate the effect of mixed glass former between TeO 2 and B 2 O 3 on the spectroscopic properties of glass. The Raman Spectroscopy has revealed a structural depolymerization undergone by the glasses with a sudden increment at x = 30 mol% that might arise from structural competition between TeO 2 and B 2 O 3. Optical absorption spectra have revealed 9 absorption peaks corresponding to Ho3+ ion transitions while one peak belongs to Yb3+ ion transition. The bonding parameter signifies the glasses are ionic in nature. The oscillator strength and Judd-Ofelt parameter Ω 2 , 4 , 6 have reduced against increment of TeO 2 concentration indicated a low asymmetry and low rigidity except for x = 30 mol% that may be due to strong interaction between TeO 2 and B 2 O 3. The radiative properties such as spontaneous emission probability, branching ratio, radiative lifetime and stimulated emission cross-section have showcased the glass potential for laser application. The luminescence spectra of studied glasses upon 450 nm excitation have disclosed two main emission bands which are 530 nm and 642 nm that corresponding to 5F 4 –5I 8 and 5F 5 –5I 8, of Ho3+ respectively whilst an extra emission recorded at 738 nm was ascribed to 5F 4 –5I 7 of Ho3+ due to energy transfer process from Yb3+ to Ho3+. The emission intensity of the samples has enhanced with the TeO 2 addition due to reduction of phonon energy. CIE 1931 diagram has shown a greener emission colour of glass samples over TeO 2 addition. [ABSTRACT FROM AUTHOR]

The multi-configuration Dirac–Hartree–Fock method is employed to investigate the Mα transitions of He-like to C-like Co ions. This study encompasses various parameters, such as energy levels, wavelengths, transition rates, oscillator strengths, and line strengths. The Breit interaction, vacuum polarization, and self-energy corrections were included in the computation of energy levels. The computed results we obtained align well with both experimental and theoretical findings. The differences for most energy levels, transition wavelengths, and oscillator strengths are all below 0.6%, 0.8%, and 20%, respectively. The uncertainty estimation method of the transitions of line strength is evaluated using quantitative and qualitative evaluation methods. The resulting accurate and consistent MCDHF data are expected to be useful for theoretical research on cobalt ions. [ABSTRACT FROM AUTHOR]