Electron Density Distribution Research Articles

In Search of Covalency Measure of Gd(III)-Ligand Interactions.

Experimental electron density distribution of the [C(NH2)3]3[Gd(EDTA)F2]·H2O crystal was determined. The derived experimental and theoretical (DFT) topological parameters such as ∇2ρc, ρc, bond degree (BD), kinetics, and potential energy were used to study the nature of Gd-O, Gd-F, and Gd-N interactions. The natural charge of the Gd is 1.86; the natural configuration of the cation is [Xe]6s0.134f7.105d0.83, and the covalency of the Gd-L bond is mainly connected with the transfer of charge from the spx ligand orbitals onto the 5d orbitals of the Gd cation. Simultaneously, the donation of charge onto the 6s and 4f orbitals occurs to a lesser extent. Moreover it was found that the donation of the ligand charges onto the Gd(III) is larger for compounds with a lower coordination number. The obtained topological parameters were analyzed in the context of the Gd(III) f-f transition properties, i.e., energy of the excited 2S+1LJ states, Judd-Ofelt intensity parameters, and luminescence lifetimes, of 18 Gd(III) compounds with various O, N, and F donor ligands (DOTA, EDTA, CDTA, DTPA, NTA, EGTA, ODA, F-, H2O, and CO32-). The calculated nephelauxetic β parameter may reflect the penetration degree of electron lone pairs of ligands inside the metal basin. Finally, it was found for the first time that the sum of the Gd(III)-L bond energy (∑EGdL) is correlated with the position of the gravity center of the 8S7/2 → 2S+1LJ transitions and increase of covalency of the Gd(III)-L bonds is associated with decrease of their bond energy. The obtained results may shed light on chemical bonding in systems containing f-elements. Such subtle differences in the covalent contribution to the Ln-L or An-L bond may tune the selectivity of the partitioning processes of lanthanides and actinides.

Enhancing device characteristics of InP quantum dot LED through structural modification with polyethylene glycol blend

This study explored the integration of polyethylene glycol (PEG) into InP-based quantum dot (QD) light-emitting diodes (LEDs). By 5 wt% of PEG 400 blended into the QD emission layer (EML), we achieved an enhancement in both current efficiency (100 %) and external quantum efficiency (91 %). X-ray reflectivity revealed significant morphological changes in the QD EML upon PEG incorporation, primarily manifesting as increased thickness in the dense surface region without affecting the total thickness. This adjustment influenced electron density distribution, impacting hole and electron flow. Overall, the addition of PEG not only improved the electrical properties of QD LEDs but also reshaped the internal morphology of the QD EML. Notably, the efficiency improvements observed rival those achieved by integrating traditional hole transport materials into QD EMLs.

Structure, Covalency, and Paramagnetism of Homoleptic Actinide and Lanthanide Amidinate Complexes.

Isostructural trivalent lanthanide and actinide amidinates bearing the N,N'-bis(isopropyl)benzamidinate (iPr2BA) ligand [LnIII/AnIII(iPr2BA)3] (Ln = La, Nd, Sm, Eu, Yb, Lu; An = U, Np) have been synthesized and characterized in both solid and solution states. All compounds were examined in the solid state utilizing single crystal X-ray diffraction (SC-XRD), revealing a notable deviation in the actinide series with shortened bond lengths compared to the trend in the lanthanide series, suggesting a nonionic contribution to the actinide-ligand bonding. Quantum-chemical bonding analysis further elucidated the nature of these interactions, highlighting increased covalency within the actinide series, as evidenced by higher delocalization indices and greater 5f orbital occupation, except for Th(III) and Pa(III), which demonstrated substantial 6d orbital occupancies. An in-depth paramagnetic NMR study in solution also sheds light on the covalent character of actinide-ligand bonding, with the separation of pseudocontact (PCS) and contact shift (FCS) contributions employing the Bleaney and Reilley method. This analysis unveiled significant contact contributions in the actinide complexes, indicating enhanced covalency in actinide-ligand bonding. To corroborate these observations, an accurate PCS calculation method based on the Kuprov equation, incorporating both the distribution of electronic spin density and magnetic susceptibility obtained from CASSCF calculations, was applied and compared with experimental values.

Studies of dynamic spatio-temporal processes of electrons in a 50 kHz/5 MHz dual-frequency dielectric barrier discharge plasma at atmospheric pressure

Dual-frequency excitation of dielectric barrier discharge (DBD) plasma reactors, where the plasma is generated by a low-frequency (LF) source and modulated by a radio-frequency (RF) source, have been widely adopted in the low-pressure regime. However, the impacts of the RF voltage and LF voltage amplitudes on the plasma parameters, including the spatiotemporal distributions of ion and electron densities, electron dynamics, and gas temperatures, remain poorly understood in the atmospheric pressure regime. The present work addresses this issue by conducting joint experimental and simulation studies for an atmospheric-pressure 50 kHz/5 MHz dual-frequency driven DBD plasma reactor based on phase-resolved optical emission spectra and a drift–diffusion model. The results demonstrate that the dynamic spatiotemporal behaviors of electrons change dramatically as the voltage of the RF component increases from 50 V to 300 V with the voltage of the LF component fixed at 1 kV. Moreover, the RF component is further demonstrated to modulate other plasma characteristics, such as particle densities, gas temperature, and argon emissions. These results contribute toward the tailoring of the non-equilibrium and nonlinear plasma parameters obtained under atmospheric pressure conditions.

Radiated power and soft x-ray diagnostics in the SMART tokamak.

A multi-energy soft x-ray diagnostic is planned to operate in the small aspect ratio tokamak (SMART), consisting of five cameras: one for core measurements, two for edge, and two for divertors. Each camera is equipped with four absolute extreme ultra-violet diodes, with three of them filtered by Ti and Al foils for C and O line emissions, respectively, and Be foils for temperature measurements. In addition, two spectrometers will be installed with a vertical line of sight for impurity control. This study introduces a synthetic model designed to characterize radiated power and soft x-ray emissions. The developed code extracts the radiated power and Zeff values by leveraging distributions of electron density, temperatures, and impurity concentrations. The investigation is centered on the predicted scenarios of SMART's first phase of operation (Ip = 100kA; Bt = 0.1T), employing a double-null configuration with positive and negative triangularity. The anticipated impurities encompass C (1%) and Fe (0.01%) from the vessel, as well as O and N (0.1%) from air and water. For simplicity, the distribution is assumed to be homogeneous within the plasma, considering different mixtures with Zeff values ranging between 1 and 2. Finally, the model estimates signal strength for the diagnostic design, proving its feasibility.

The effect of perfluoroalkyl chain length and the type of acid group on PFAS adsorption from water

Widespread use of per- and polyfluoroalkyl substances (PFAS) poses significant ecological and health risks due to their non-degradability in the environment and consequent bioaccumulation in humans. In this work, we carried out a systematic computational study to unravel the effect of perfluorinated carbon chain length and the type of acid head group on the adsorption mechanism of PFAS from water. We considered the adsorption of perfluoroalkyl carboxylic acids (PFCA) and perfluoroalkyl sulfonic acids (PFSA) with chain lengths of three to eight perfluorinated carbons in hydrophobic all-silica zeolite Beta. Molecular dynamics (MD) simulations coupled with enhanced sampling calculations showed that adsorption free energies of both PFCA and PFSA decreased with increasing number of perfluorinated carbons. Calculated free energies further showed that PFCA and PFSA, which are anions in water, must overcome substantially large interfacial energy barriers to be adsorbed in hydrophobic pores. Subsequent ab initio MD simulations revealed that PFCA and PFSA gain a proton at the water – zeolite interface and are eventually adsorbed in neutral form. Breakdown of guest – host interaction energies into hydrophobic and polar components showed that hydrophobic interactions dominate PFCA adsorption whereas polar interactions are dominant in PFSA adsorption. This is due to sulfonic acid giving rise to stronger electrostatic interactions and the rearrangement of the electron density distribution in the perfluorinated carbon chain, which render the hydrophobic interactions relatively weaker. Our study reveals that a combination of adsorbents that provide optimised hydrophobic and polar interactions should be used for the capture of diverse PFAS from water.

Investigating the effect of Pb doping on the structural, electronic, magnetic, and optical properties of wurtzite CdS

This study focuses on comprehensively investigating the crystal structure, electronic, magnetic and optical properties of pure and Pb-doped CdS at different concentrations using first-principles methods with the GGA-PBE+U approximation. Our calculations successfully reproduce the experimentally observed optimized lattice parameters and band gap values for both pure and Pb-doped CdS systems. Band structure results show a large and significant reduction in the band gap of Pb-doped CdS at low concentrations, followed by a steady increase at high Pb concentrations. The electron density distribution show the covalent nature between Cd-S and Pb-S. The optical properties of pur and Pb-doped CdS show: a significant increase in absorption and in reflectivity in the visible and ultraviolet domains with doping. Finally, a reduction in optical transmission in the visible energy domain. These optical analyzes provide essential information on the behavior of these materials, thus broadening its practical applications, notably in the design of optoelectronic devices.

Floatable expanded perlite-loaded Z-scheme n-C3N5/Ag2CO3 core-shell structure with C-defects for enhanced adsorption and photodegradation of microcystin-LR: Insights into performance and mechanism

Efficient in-situ treatment of high concentrations microcystin-LR in surface waters is especially challenging. Herein, spherical floatable Z-scheme core-shell photocatalyst EP@n-C3N5/Ag2CO3 (EP@CNAC) with carbon defects was constructed using expanded perlite (EP) as floating carrier for efficient adsorption and degradation of microcystin-LR. The carbon defect sites and electron density distribution of C3N5 were investigated by DFT calculation. Benefited from synergistic effects of morphology and defect engineering, Z-scheme heterojunction, and floatability, the carrier migration kinetics and solar spectral responsiveness of EP@CNAC-3 were significantly enhanced, and 97% of microcystin-LR was degraded within 16min. The LC-MS, Fukui index, and electrostatic potential of microcystin-LR revealed that Adda side chain was cleaved by electrophilic attack of 1O2, while ring-opening reaction and decarboxylation were caused by nucleophilic attack of •O2- and strong oxidative properties of h+, respectively. These findings are expected to bring new insights into design of innovative floating photocatalysts and in-situ remediation mechanism of microcystin-LR.

Preliminary Exploration of Low Frequency Low-Pressure Capacitively Coupled Ar-O2 Plasma

Non-thermal plasma as an emergent technology has received considerable attention for its wide range of applications in agriculture, material synthesis, and the biomedical field due to its low cost and portability. It has promising antimicrobial properties, making it a powerful tool for bacterial decontamination. However, traditional techniques for producing non-thermal plasma frequently rely on radiofrequency (RF) devices, despite their effectiveness, are intricate and expensive. This study focuses on generating Ar-O2 capacitively coupled plasma under vacuum conditions, utilizing a low-frequency alternating current (AC) power supply, to evaluate the system’s antimicrobial efficacy. A single Langmuir probe diagnostic was used to assess the key plasma parameters such as electron density (ne), electron temperature (Te), and electron energy distribution function (EEDF). Experimental results showed that ne increases (7 × 1015 m−3 to 1.5 × 1016 m−3) with a rise in pressure and AC power. Similarly, the EEDF modified into a bi-Maxwellian distribution with an increase in AC power, showing a higher population of low-energy electrons at higher power. Finally, the generated plasma was tested for antimicrobial treatment of Xanthomonas campestris pv. Vesicatoria. It is noted that the plasma generated by the AC power supply, at a pressure of 0.5 mbar and power of 400 W for 180 s, has 75% killing efficiency. This promising result highlights the capability of the suggested approach, which may be a budget-friendly and effective technique for eliminating microbes with promising applications in agriculture, biomedicine, and food processing.

Investigation of Partial Discharge Transformation Characteristics in Polyimide (PI) Insulations under High-Frequency Electric Stress.

This research delves into the primary issue of polyimide (PI) insulation failures in high-frequency power transformers (HFPTs) by scrutinizing partial discharge development under high-frequency electrical stress. This study employs an experimental approach coupled with a plasma simulation model for a ball-sphere electrode structure. The simulation model integrates the particle transport equation, Poisson equation, and complex chemical reactions to ascertain microscopic parameters, including plasma distribution, electric field, electron density, electron temperature, surface, and space charge distribution. The effect of the voltage polarity and electrical energy on the PD process is also discussed. The contact point plays a pivotal role in triggering partial discharges and culminating in the breakdown of PI insulation. Asymmetry phenomena were found between positive and negative half-cycles by analyzing the PD data stage by stage. A significant number of PDs increased at every stage and the PD amplitude was higher during the negative cycle at the initial stage, but in later stages, the PD amplitude was found to be higher in the positive half-cycle, and scanning electron microscopy (SEM) revealed that the maximum damage occurred near the contact point junction. The simulation results show that the plasma initially accumulates the electron density near the contact point junction. Under the action of the electric field, plasma starts traveling at the PI surface outward from the contact point. Before the PD activity, all parameters have higher values in the plasma head. The microscopic parameters reveal maximum values near the contact point junction, during PD activities where significant damage takes place. These parameter distributions exhibit a decreasing trend over time as when the PD activity ends. The model's predictions are consistent with the experimental data. The paper lays the foundation for future research in polymer insulation design under high-frequency electrical stress.

Flurbiprofen clubbed schiff's base derivatives as potent anticancer agents: In Vitro and In Silico approach towards breast cancer

In this work, we are reporting nineteen hydrazone-Schiff base derivatives (2a-2l and 3a-3g), containing flurbiprofen drug nucleus. The synthesized products were structurally elucidated through 1H, 13C-NMR and HR-ESI-MS spectroscopic techniques and finally tested for in vitro anti-cancer activity. Among the synthetic series, 2f, 2g, 3g, 3b, and 2e attributed the higher inhibitory potential against the breast cancer cell line (MDA-MB-231) having IC50 values of 21.0 ± 0.4, 21.8 ± 0.2, 27.1 ± 0.3, 28.8 ± 0.3, and 29.6 ± 0.3 µM respectively. However, the remaining derivatives attributed good to less active. DFT was used to calculate frontier molecular orbital of (2a-h, j-l, and 3a-d) including HOMO which concentrated on the substituents aromatic ring, and LUMO focused over flurbiprofen and hydrazide fragments, that indicate the charge transfer from molecule to biological media. The reactivity indices suggested the most active 2f (IC50 = 21.0 ± 0.4 µM) and 2g (IC50 = 21.8 ± 0.2 µM) showed higher indices reactivity namely σ, χ, and ω than lowest active 2g; this relation inversely for Eg, η, and IP. 2a-l had more electrophilic character and higher acceptance ability for biological targets than compounds (3a-g). The MEP map indicated the electron density distribution of 2a-l was more dispersed than that of 3a-g, indicating potential biological activities and are chemically reactive zone suitable for drug action. The docking study contributed to the analysis of cytotoxicity for investigated compounds.

First-principle study of the ground-state crystal structure and optoelectronic response of CsPbX3 (X= Cl, Br, I) for photovoltaic applications

The optoelectronic response and ground state crystal structure of tetragonal (P4/mbm), orthorhombic (Pmnb) and monoclinic (P21/m) phases of CsPbX3 (X = Cl, Br, I) are studied for optoelectronic applications using first principle simulations. Electric field gradient (EFG) and magnetic hyperfine interactions are investigated to explore the charge distributions surrounding the nucleus and local magnetic environment of the atomic nucleus. The orthorhombic phase of these compounds is more stable having lowest ground-state energy compared to tetragonal and monoclinic phases. The understudied halide perovskites have direct band gap nature and spin orbit coupling (SOC) effect splits Pb-p and X-p orbitals at the edges of conduction and valence band (CB and VB) respectively. At the edge of VB, the strongly hybridized X-p and Pb-p orbital and direct band gap nature of CsPbX3 is excellent for the light absorption and photovoltaic (PV) applications. The n-i-p configuration (FTO/ETL/CsPbX3/HTL/Au) of the simulated structure shows that CsPbI3 has improved power conversion efficiency (PCE) of 22.48 % and 22.32 % and quantum efficiency (QE) about ∼80 % in tetragonal and monoclinic phases respectively. The Pb and Cs values of EFG tensor in z-direction (Vzz) are close to each other, which show that the distribution of electronic charge density is similar near these nuclei. Moreover, Cs-s orbital has negligible contribution and Pb-p and I-p orbitals have higher contribution in the hyperfine field (HFF). The negative HFF indicates the opposite HFF contribution.

Assessments of the key plasma parameters with different scenarios on HIT-PSI using EMC3-EIRENE

Linear plasma devices offer an effective way to conduct plasma-wall interaction studies and contribute to a basic understanding of edge plasma physics. A new platform at Harbin Institute of Technology for Plasma Surface Interaction experiments (HIT-PSI) is a newly-built linear device at the stage of commissioning that is capable of simulating high heat power deposition on divertor targets similar to tokamak conditions. Therefore, numerical simulations to evaluate the plasma characteristics are essential for designing and guiding the experimental conditions in HIT-PSI. In this work, the three-dimensional edge transport code EMC3-EIRENE has been used to investigate the plasma parameter distributions in HIT-PSI with the puffing and pumping systems involved. The effects of the heating power and target position on the distribution of electron density, electron temperature, and particle and heat fluxes have been investigated by EMC3-EIRENE. Particularly, the reduction in the electron density with the puffing fluxes has also been studied by analyzing individual atomic and molecular processes. Finally, the influence of varying pumping speeds on plasma parameters has been investigated in detail by adjusting the recycling coefficients at the two pumping ports.

Electron Density Distribution in H ii Regions in IC 10

We present the [O III] λ52 μm map of the dwarf galaxy IC 10 obtained with the Field-Imaging Far-Infrared Line Spectrometer on board the Stratospheric Observatory for Infrared Astronomy. We combine the [O III] λ52 μm map with Herschel and Spitzer observations to estimate the electron density distribution of the brightest H ii regions of IC 10. We find that the line ratio [O III] λ88 μm/[O III] λ52 μm gives electron density (n e) values (n e [O III]) that cover a broad range, while the n e values obtained using the line ratio [S III] λ33 μm/[S III] λ18 μm (n e [S III]) are all similar within the uncertainties. n e [O III] is similar to n e [S III] for the M1, M2, and A1 regions, and it is higher than n e [S III] for the two regions, A2 and M1b, which are the brightest in the 24 μm continuum emission. These results suggest that for these regions, the two ions, O++ and S++, trace two different ionized gas components and that the properties of the ionized gas component traced by the O++ ion are more sensitive to the local physical conditions. In fact, while the gas layer traced by [S III] does not keep track of the characteristics of the radiation field, the n e [O III] correlates with the star formation rate, the dust temperature, and the 24 μm. Therefore, n e [O III] is an indicator of the evolutionary stage of the H ii region and the radiation field, with higher n e [O III] found in younger star-forming regions and in more energetic environments.

Understanding Activity and Stability of Ru1-XMxO2 Oxygen Evolution Reaction Catalyst Surfaces (M = Ti, Zr): Theory and Experiments

Proton-exchange membrane water electrolyzers, pivotal for sustainable hydrogen production, encounter challenges in the oxygen evolution reaction (OER) marked by high overpotential and limited electrocatalyst stability. This study delves into the computational exploration of two metal substitutions, titanium (Ti) and zirconium (Zr), within ruthenium oxide (RuO2), aiming to enhance catalytic stability. The investigation encompasses nanoscale titanium-substituted and zirconium-substituted rutile RuO2, (Ru1-xMxO2) and evaluating their atomic and electronic structures, OER activity, and dissolution behavior.In the case of Ti substitution, varying concentrations (x = 0–50 at %) were systematically investigated. Our experiments and theoretical analyses elucidate concentration-dependent effects on the electronic structure, showcasing shifts in the d-band and O2p band centers. Titanium substitution induces electron accumulation and depletion regions on the surface, influencing OER activity and stability. Electrochemical testing corroborates the theory, demonstrating that lower Ti concentrations (12.5 and 20 at %) enhance catalyst stability and mitigate ruthenium dissolution. Specifically, Ti substitution influences reaction pathways, with penta-coordinated Ru sites exhibiting the lowest barriers for OER, while hexa-coordinated Ru sites facilitate lower energetic barriers for dissolution.Simultaneously, the study extends to the substitution of Zr within rutile RuO2. Computational and experimental analyses reveal anisotropic shifts in the rutile unit cell, dependent on Zr concentration. Zr substitution induces alterations in the electronic structure, impacting the surface density of states and electron density distribution. Experimentally, lower OER activity is observed for Zr-substituted RuO2 compared to pure RuO2, consistent with computational averages across all sites. However, specific sites with Zr substitution exhibit higher theoretical OER activity. Dissolution analyses underscore the complexity of interactions, with Zr affecting activation barriers for Ru dissolution, thus influencing OER stability.Notably, the dissolution behavior emerges as a critical aspect of this investigation. In Ti-substituted RuO2, experimental accelerated durability testing showcases enhanced stability and reduced Ru dissolution at low and intermediate Ti concentrations. Computational analyses corroborate these findings, indicating site-specific effects on both OER activity and stability. Conversely, Zr-substituted RuO2 exhibits lower Ru dissolution compared to commercial RuO2, emphasizing the role of Zr in impeding Ru dissolution while contributing to surface restructuring.In conclusion, this comprehensive exploration of Ti and Zr substitutions within ruthenium oxide advances our understanding of their effects on atomic and electronic structures, OER activity, and dissolution dynamics. The intricate interplay between specific sites, metal concentrations, and substituents provides valuable insights for designing high-performance, cost-effective OER nanoscale electrocatalysts. The findings underscore the importance of considering both activity and stability in the pursuit of efficient and durable electrocatalysts for sustainable hydrogen production.

Exploring the Impact of Oxygen Doping in Li2FeS2 Cathode Materials for Li-Ion Batteries

Over the past few decades, rechargeable lithium-ion batteries have become popular for a variety of applications, such as electric vehicles, smart grids, and portable energy devices. However, due to their limited capacity, stability, and lifespan, they are not suitable for advanced transportation applications. To overcome these challenges, researchers have investigated the use of low-cost, high-energy-density, and safe positive electrode materials for secondary lithium batteries, including lithium iron sulfide. In this particular study, our focus is to investigate the effect of highly electronegative anion doping on the properties of lithium iron sulfide cathode through the solid-state method. Our approach involves using both in-situ and ex-situ observations to establish a correlation between the Redox behavior and structural properties of the prepared cathode materials. We have designed and characterized the material using various techniques, such as X-ray absorption spectroscopy (XAS) and synchrotron-based X-ray diffraction (XRD). Scanning electron microscope (SEM) measurement was conducted to study the morphology of the cathode material. Transmission electron microscopy (TEM) was employed to further study the microstructure of the cathode material at an atomic level. We analyzed the electron density distribution of the modified cathode material using XANES measurement and studied the structural properties through synchrotron-based XRD. Our study has revealed that oxygen-doping helps to improve material stability. As a result, the modified cathode (with optimal oxygen doping) exhibited a 50% capacity enhancement compared to pristine after 100 cycles. We also observed a shift to a higher voltage oxidation plateau of the oxygen-doped cathode material which is due to the influence of anion substitution on the electrochemistry and charge storage mechanisms. In summary, our detailed characterization and experimental results demonstrate the potential of oxygen-doped Li2FeS2 as a promising cathode material for advanced lithium-ion battery applications. The study's detailed characterization and experimental results will be presented, along with future perspectives.

Computational Investigations on Bis‐(ferrocenylmethyl)‐Based Sulphur Rich Sensitizers for Dye‐Sensitized Solar Cells

AbstractIn this work, a computational investigation of ferrocene (Fc)‐based compounds FcCH2CS3CH2Fc (1) and FcCH2SSCH2Fc (2) sensitizer for dye‐sensitized solar cells (DSSCs) has been carried out to comprehend the photophysical and photo‐electrochemical properties. The density functional theory (DFT) and time‐dependent DFT (TD‐DFT) were employed to assess the photovoltaic parameters of the compounds. The frontier molecular orbital analysis revealed the electron density distribution at HOMO and LUMO, which clearly demonstrates the charge separation within the compounds. The electronic absorption spectra are simulated using the TD‐DFT method to comprehend the ability of the compounds to harvest sunlight and efficiently act as photosensitizer. Simulation of electronic spectra of dye@TiO2 cluster exhibits that the absorption coefficient of compound 1 is higher than compound 2 due to the greater extent of charge transfer from the dye to the TiO2 cluster. These computational findings are corroborated by the reported photovoltaic performance of the compounds.

Probing photoinduced electron transfer events in phenylferrocene-corrole dyad.

Herein, we investigated PhFC (10-phenylferrocenyl-5,15-diphenyl corrole), a corrole-based donor-acceptor (D-A) dyad, to understand the energy/electron transfer reaction dynamics. Phenylferrocene acts as the donor moiety when attached to the meso position of the corrole ring in the PhFC D-A system. The photophysical properties of the PhFC dyad and its parent molecule, TPC (5,10,15-triphenyl corrole), were studied by UV-vis spectroscopy, steady state fluorescence spectroscopy, TCSPC and optical microscopy techniques. A slight red shift and broadening of both the Q-band and Soret bands are observed in the absorption spectra of the PhFC dyad in comparison to TPC, representing the weak electronic interaction between the phenylferrocene moiety and corrole ring. The fluorescence emission spectrum of the PhFC dyad is significantly quenched (>80%) in comparison to TPC, attributed to the photoinduced electron transfer (PET) from phenylferrocene to the corrole ring. We observed that the electron transfer rate in the PhFC system is solvent dependent. Our theoretical investigation supported the experimental findings on the electron transfer mechanism. The HOMO and LUMO arrangements of these PhFC dyads demonstrate the electron density distribution and the ability of the donor moieties to transfer electrons to the corrole moiety. Fluorescence lifetime imaging microscopy (FLIM) was used to image the homogeneous lifetime distribution of the PhFC dyad and TPC.

Investigation on Chasing and Interaction of Traveling Ionospheric Disturbances Based on Multi‐Instrument

AbstractIn this study, we use multi‐instrument observations (all‐sky imager (ASI), global navigation satellite system (GPS) receivers, digisonde) to study the interaction of nighttime medium‐scale traveling ionospheric disturbances (MSTIDs) on 13 November 2018. The most attractive aspect of this event is that the interaction appeared between two dark bands both propagated southwestward. The airglow observations show that the latter band moved faster and caught up with the former, and these two bands merged into a new one. The propagating characteristics and morphology of the MSTIDs changed during the interaction process. The simulations from the Thermosphere‐Ionosphere‐Electrodynamics General Circulation Model (TIEGCM) suggested that the ionospheric background zonal winds and electron density distributions could play essential roles in the interaction of the MSTIDs. Moreover, the merging process might be associated with the electrostatic reconnection.

The effect of the external magnetic field on the power of the laser passing through the magnetized plasma and the calculation of the radius of convergence and the investigation of the condition of the beam's filamentation in the Medium

In this article, the power of a laser passing through a magnetized plasma medium which is affected by an external magnetic field is calculated.The change in the intensity of the magnetic field and its rotation around the axis of laser beam propagation in the plasma, on the power of the passing beam is investigated.This work is done based on the indirect effect of the magnetic field on the density distribution of electrons in the plasma, which we can consider the density changes as changes in the refractive index of the medium, so the laser power in this case is different from the case where there is no magnetic field. Also, the condition of beam filamentation has been researched as one of the third-order nonlinear phenomena, and the convergence radius has been calculated under these conditions.