Fully relativistic energies,transition properties,and lifetimes of lithium-like germanium

Employing two fully relativistic methods,the multi-reference configuration Dirac-Hartree-Fock(MCDHF)methodand the relativistic many-body perturbation theory(RMBPT)method,we report energies and lifetime values for the lowest35 energy levels of the(1s^(2))nl configurations(where the principal quantum number n=2-6 and the angular quantum numberl=0,...,n-1)of lithium-like germanium(Ge XXX),as well as complete data on the transition wavelengths,radiativerates,absorption oscillator strengths,and line strengths between the levels.Both the allowed(E1)and forbidden(magneticdipole M1,magnetic quadrupole M2,and electric quadrupole E2)ones are reported.The results from the two methodsare consistent with each other and align well with previous accurate experimental and theoretical findings.We assess theoverall accuracies of present RMBPT results to be likely the most precise ones to date.The present fully relativistic resultsshould be helpful for soft x-ray laser research,spectral line identification,plasma modeling and diagnosing.The datasetspresented in this paper are openly available at https://doi.org/10.57760/sciencedb.j00113.00135.

Fully relativistic many-body perturbation energies,transition properties,and lifetimes of lithium-like iron Fe XXIV

Employing the advanced relativistic configuration interaction(RCI)combined with the many-body perturbation theory(RMBPT)method,we report energies and lifetime values for the lowest 35 energy levels from the(1s^(2))nl configurations(where the principal quantum number n=2–6 and the angular quantum number l=0,...,n-1)of lithium-like iron Fe XXIV,as well as complete data on the transition wavelengths,radiative rates,absorption oscillator strengths,and line strengths between the levels.Both the allowed(E1)and forbidden(magnetic dipole M1,magnetic quadrupole M2,and electric quadrupole E2)ones are reported.Through detailed comparisons with previous results,we assess the overall accuracies of present RMBPT results to be likely the most precise ones to date.Configuration interaction effects are found to be very important for the energies and radiative properties for the ion.The present RMBPT results are valuable for spectral line identification,plasma modeling,and diagnosing.

Impacts of hydrogen annealing on the carrier lifetimes in p-type 4H-SiC after thermal oxidation

Thermal oxidation and hydrogen annealing were applied on a 100μm thick Al-doped p-type 4H-Si C epitaxial wafer to modulate the minority carrier lifetime,which was investigated by microwave photoconductive decay(μ-PCD).The minority carrier lifetime decreased after each thermal oxidation.On the contrary,with the hydrogen annealing time increasing to3 hours,the minority carrier lifetime increased from 1.1μs(as-grown)to 3.14μs and then saturated after the annealing time reached 4 hours.The increase of surface roughness from 0.236 nm to 0.316 nm may also be one of the reasons for limiting the further improvement of the minority carrier lifetimes.Moreover,the whole wafer mappings of minority carrier lifetimes before and after hydrogen annealing were measured and discussed.The average minority carrier lifetime was up to 1.94μs and non-uniformity of carrier lifetime reached 38%after 4-hour hydrogen annealing.The increasing minority carrier lifetimes could be attributed to the double mechanisms of excess carbon atoms diffusion caused by selective etching of Si atoms and passivation of deep-level defects by hydrogen atoms.

Relativistic calculations on the transition electric dipole moments and radiative lifetimes of the spin-forbidden transitions in the antimony hydride molecule

Calculations on the spectroscopic constants and transition properties of the first three states(a^(1)△,b^(1)Σ^(+),and X3Σ-)of the Sb H molecule were performed under the relativistic framework using the exact two-component Hamiltonian(X2C).The potential energy curves in the Franck-Condon region were computed and compared with the previous values.Furthermore,the transition dipole moments for the weak spin-forbidden transitions(b0^(+)-X10^(+),b0^(+)-X_(2)1,X10^(+)-X_(2)1,and X_(2)1-a2)were reported.The spontaneous radiative lifetime of the b1Σ^(+)(υ′=0)state was calculated as 163.5±7.5μs,which is in reasonable agreement with the latest experimental value of 173±3μs.The spontaneous radiative lifetimes of the X_(2)1(υ′=0)state and the a2(υ′=0)state were calculated to be 48.6 s and~8 ms,respectively.Our study is expected to be a benchmark transition property computation for comparison with other theoretical and experimental results.The datasets presented in this paper,including the transition dipole moments,are openly available at https://dx.doi.org/10.11922/sciencedb.j00113.00018.

Reconciliation of Theoretical Lifetimes of the 5s5p^(3)P_(2)^(o) Metastable State for ^(88)Sr with Measurement: The Role of the Blackbody-Radiation-Induced Decay

We conducted measurement and calculation to resolve the long-standing large discrepancy in the metastable state lifetime for the ^(88)Sr atom between theoretical and experimental results. The present lifetime τ = 830_(-240)^(+600)s,measured using the magneto-optical trap as a photon amplifier to detect the weak decay events, is approximately60% larger than the previous experimental value τ = 520_(-140)^(+310)s. By considering the electron correlation effects in the framework of the multiconfiguration Dirac–Hartree–Fock theory, we obtained a theoretical lifetime of 1079(54) s, which lies in the range of measurements with error bars. Furthermore, we considered the higher-order electron correlation and Breit interaction to control the uncertainty of the theoretical calculation. The significant improvement in the agreement between calculations and measurements is attributed to the updated blackbody radiation-induced decay rate.

Semi-Empirical Oscillator Strengths and Lifetimes for the P IV Spectrum

In this work numerical codes carried out in a multiconfiguration Har-tree-Fock relativistic (HFR) approach for the P IV ion are used to obtain the oscillator strengths of each transition as well as the lifetimes of each energy level. With the existing data from several authors that contributed to the spectrum using different light sources, and optimizing the electrostatic parameters by a least-squares procedure when replacing the theoretical values by the experimental ones in the energy matrices, one obtains closer values and according to the observations for the intensities, and also of the lifetimes closer to those that would be obtained experimentally.

Oscillator Strengths and Lifetimes for the P XIII Spectrum

The P XIII spectrum has been analyzed by several authors using different light sources. The semi-empirical oscillator strengths (gf) and the lifetimes presented in this work for all known P XIII spectral lines and energy levels were carried out in a multi-configuration Hartree-Fock relativistic (HFR) approach. In this calculation, the electrostatic parameters were optimized by a least-squares procedure in order to improve the adjustment of theoretical to experimental energy levels. The method produces gf-values that are in agreement with intensity observations and lifetime values closer to the experimental ones.

Theoretical study of potential energy curves,spectroscopic constants,and radiative lifetimes of low-lying states in an SeO molecule

The low-lying potential energy curves of the SeO molecule are computed by means of an ab initio multireference configuration interaction technique, taking into account relativistic （scalar plus spin~）rbit coupling） effects. The spectroscopic constants of Ω states for X3∑-, a1△, b2∑＋, A3П , A′3△, and A″ 3∑＋ states are obtained, and they are in good accordance with available experimental values. The Franck-Condon factors and transition dipole moments to the ground state are computed, and the natural radiative lifetimes of low-lying Ω states are theoretically obtained. Comparisons of the natural lifetimes of Ω states with previous experimental results and those of isovalent TeO molecule are made.

Spectroscopic properties and radiative lifetimes of SiTe:A high-level multireference configuration interaction investigation

The 18 A-S states correlated to the lowest dissociation limit of SiTe were calculated by using a high-level multirefer-ence configuration interaction （MRCI） method, including scalar relativistic and spin-orbit coupling effects. Based on the calculated potential energy curves, the spectroscopic constants of bound states were determined, which are well consistent with previous experimental results. The spin-orbit matrix elements between the A-S states were computed, which lead to an in-deoth understanding, of oerturbations on the electronic state a^3∏. Finally. the transition dioole moments of allowed transitionsA^1∏-X^1∑^＋,E^1∑^＋-X^1∑^＋,a^3∏-d^3△,a^3∏-d^3△,a^∏-a′^3∑^＋,a^3∏-e^3∑^-,and the radiative lifetimes of A^1∏,E^1∑^＋,and a^3∏ were evaluated.

Lifetimes of Rydberg states of Eu atoms

The radiative lifetimes of the Eu 4f76snp（8^PJ or10^PJ） Rydberg states with J = 5/2 and 11/2 are investigated with a combination of multi-step laser excitation and pulsed electric field ionization, from which their dependence on the effective principal quantum number is observed. The lifetimes of 21 states are reported along with an evaluation of their experimental uncertainty. The influence of blackbody radiation, due to the oven temperature, on the lifetime of the higher-n states is detected. The non-hydrogen behavior of the investigated states is also observed.

Improving resource-constrained IoT device lifetimes by mitigating redundant transmissions across heterogeneous wireless multimedia of things

In Wireless Multimedia Sensor Networks(WMSNs),nodes capable of retrieving video,audio,images,and small scale sensor data,tend to generate immense traffic of various types.The energy-efficient transmission of such a vast amount of heterogeneous multimedia content while simultaneously ensuring the quality of service and optimal energy consumption is indispensable.Therefore,we propose a Power-Efficient Wireless Multimedia of Things(PE-WMoT),a robust and energy-efficient cluster-based mechanism to improve the overall lifetime of WMSNs.In a PE-WMoT,nodes declare themselves Cluster Heads(CHs)based on available resources.Once cluster formation and CH declaration processes are completed,the Sub-Cluster(SC)formation process triggers,in which application base nodes within close vicinity of each other organize themselves under the administration of a Sub-Cluster Head(SCH).The SCH gathers data from member nodes,removes redundancies,and forwards miniaturized data to its respective CH.PE-WMoT adopts a fuzzy-based technique named the analytical hierarchical process,which enables CHs to select an optimal SCH among available SCs.A PE-WMoT also devises a robust scheduling mechanism between CH,SCH,and child nodes to enable collision-free data transmission.Simulation results revealed that a PE-WMoT significantly reduces the number of redundant packet transmissions,improves energy consumption of the network,and effectively increases network throughput.

Transition probabilities and lifetimes of the low-lying levels of Fe XIV

The multi-configuration Dirac-Fock method is employed to calculate the transition energies, probabilities, and oscillator strengths for electric dipole allowed （El） and forbidden （M1, E2, M2） lines for the 3s^23p, 3s3p^2, 3s^23d, 3p^3, and 3s3p3d configurations of Fe XIV. The lifetimes of all 40 levels of these low-lying configurations are also derived. The valence valence and core-valence correlation effects are accounted for in a systematic way. Breit interactions and quantum electrodynamics （QED） effects are estimated in subsequent relativistic configuration interaction （CI） calculations. The present results are in good agreement with other available theoretical and experimental values, and therefore can be used for the further astrophysical investigations.

High Performance Recycling of Polymers by Means of Their Fluorescence Lifetimes

Technical polymers could be identified by means of their remarkably strong auto fluorescence. The time constants of this fluorescence proved to be characteristic for the individual polymers and can be economically determined by integrating procedures. The thus obtained unequivocal identification is presented for their sorting for recycling. Furthermore, polymeric materials were doped with fluorescent dyes allowing a fine-classification of special batches.

Aggregation-induced conversion from TADF to phosphorescence of gold(I)complexes with millisecond lifetimes

Long-lived luminescent materials possess wide application prospects in various areas,but their constructions still face a huge challenge,especially the achievement in solution.Manipulating aggregate is an effective method to attain intriguing luminescence,thus it is expected to build long-lived materials in solution.In this work,a series of new gold(I)complexes were developed by employing unique carbazole and phosphine as the ligands,and these resulting systems exhibited rare long lifetimes of milliseconds in the aggregate state.It was well unveiled that these complexes emitted blue thermally activated delayed fluorescence(TADF)with the lifetimes of several microseconds in dilute solution;while orange-red phosphorescence with much longer lifetimes of several milliseconds were achieved in the aggregate state.To our knowledge,this is the first implementation of aggregation-induced conversion from TADF to phosphorescence.Based on their excellent luminescent properties,we successfully applied these complexes in cell imaging and inhibition of cancer cells.

Energy levels and radiative lifetimes of 3pns ~3p_0 and 3pnd ~3P_0 series of SiⅠ

The energy levels and lifetimes of 3pns ^3po （n = 7 - 35） and 3pnd ^3p0 （n = 6 - 17） series of neutral silicon are calculated and predicted by means of multichannel quantum defect theory （MQDT）. In addition, the perturbation caused by core-excited state 3s3p^3 is discussed. The 3pnd ^3p0 series, especially 3p4d ^3p0, 3p5d ^3P0, and 3p6d ^3P0 are perturbed strongly by the core-excited state 3s3p3 ^3P0. These cause the lifetime of 3pnd ^3P0 （n = 5 - 7） to be less than that of 3p4d 3Po. The lifetimes of 3p14d ^3P0 （65479.14 cm^-1） and 3p16d ^3p0 （65608.77 cm^-1） are less than that of their frontal states respectively, because these states are perturbed by 3p22s ^3p0 （65476.48 cm-1） and 3p30s ^3p0 （65608.99 cm^-1） respectively.

Dynamic Deep Learning for Enhanced Reliability in Wireless Sensor Networks: The DTLR-Net Approach

In the world of wireless sensor networks(WSNs),optimizing performance and extending network lifetime are critical goals.In this paper,we propose a new model called DTLR-Net(Deep Temporal LSTM Regression Network)that employs long-short-term memory and is effective for long-term dependencies.Mobile sinks can move in arbitrary patterns,so the model employs long short-term memory(LSTM)networks to handle such movements.The parameters were initialized iteratively,and each node updated its position,mobility level,and other important metrics at each turn,with key measurements including active or inactive node ratio,energy consumption per cycle,received packets for each node,contact time,and interconnect time between nodes,among others.These metrics aid in determining whether the model can remain stable under a variety of conditions.Furthermore,in addition to focusing on stability and security,these measurements assist us in predicting future node behaviors as well as how the network operates.The results show that the proposed model outperformed all other models by achieving a lifetime of 493.5 s for a 400-node WSN that persisted through 750 rounds,whereas other models could not reach this value and were significantly lower.This research has many implications,and one way to improve network performance dependability and sustainability is to incorporate deep learning approaches into WSN dynamics.

Insights and reviews on battery lifetime prediction from research to practice

The rising demand for energy storage solutions,especially in the electric vehicle and renewable energy sectors,highlights the importance of accurately predicting battery health to enhance their longevity and reliability.This article comprehensively examines various methods used to forecast battery health,including physics-based models,empirical models,and equivalent circuit models,among others.It delves into the promise of data-driven prognostics,utilizing both conventional machine learning and cuttingedge deep neural network techniques.The advantages and limitations of hybrid models are thoroughly analyzed,with a focus on the benefits of integrating diverse data sources to improve prognostic precision.Through practical case studies,the article showcases the effectiveness and flexibility of these approaches.It also critically addresses the challenges encountered in applying battery health prognostics in realworld scenarios,such as issues of scalability,complexity,and data anomalies.Despite these challenges,the article underscores the emerging opportunities brought about by recent technological,academic,and research advancements.These include the development of digital twin models for batteries,the use of data-centric AI and standardized benchmarking,the potential integration of blockchain technology for enhanced data security and transparency,and the synergy between edge and cloud computing to boost data analysis and processing.The primary goal of this article is to enrich the understanding of current battery health prognostic techniques and to inspire further research aimed at overcoming existing hurdles and tapping into new opportunities.It concludes with a visionary perspective on future research directions and potential developments in this evolving field,encouraging both researchers and practitioners to explore innovative solutions.

Self-confocal NIR-II fluorescence microscopy for multifunctional in vivo imaging

Fluorescence imaging in the second near-infrared window(NIR-II,900–1880 nm)with less scattering background in biological tissues has been combined with the confocal microscopic system for achieving deep in vivo imaging with high spatial resolution.However,the traditional NIR-IIfluorescence confocal microscope with separate excitation focus and detection pinhole makes it possess low confocal e±ciency,as well as di±cultly to adjust.Two types of upgraded NIR-IIfluorescence confocal microscopes,sharing the same pinhole by excitation and emission focus,leading to higher confocal e±ciency,are built in this work.One type is-ber-pinhole-based confocal microscope applicable to CW laser excitation.It is constructed forfluorescence intensity imaging with large depth,high stabilization and low cost,which could replace multiphotonfluorescence microscopy in some applications(e.g.,cerebrovascular and hepatocellular imaging).The other type is air-pinhole-based confocal microscope applicable to femtosecond(fs)laser excitation.It can be employed not only for NIR-IIfluorescence intensity imaging,but also for multi-channelfluorescence lifetime imaging to recognize different structures with similarfluorescence spectrum.Moreover,it can be facilely combined with multiphotonfluorescence microscopy.A single fs pulsed laser is utilized to achieve up-conversion(visible multiphotonfluorescence)and down-conversion(NIR-II one-photonfluorescence)excitation simultaneously,extending imaging spectral channels,and thus facilitates multi-structure and multi-functional observation.

Stable photocurrent-voltage characteristics of perovskite single crystal detectors obtained by pulsed bias

Photocurrent-voltage characterization is a crucial method for assessing key parameters in x-ray or y-ray semiconductor detectors,especially the carrier mobility lifetime product.However,the high biases during photocurrent measurements tend to cause severe ion migration,which can lead to the instability and inaccuracy of the test results.Given the mixed electronic-ionic charac teristics,it is imperative to devise novel methods capable of precisely measuring photocurrentvoltage characteristics under high bias conditions,free from interference caused by ion migration.In this paper,pulsed bias is employed to explore the photocurrent-voltage characteristics of MAPbBr_(3) single crystals.The method yields stable photocurrent-voltage characteristics at a pulsed bias of up to 30 V,proving to be effective in mitigating ion migration.Through fitting the modified Hecht equation,we determined the mobility lifetime products of 1.0×10^(2) cm^(2)·V^(-1)for hole and 2.78×10~(-3)cm^(2)·V^(-1)for electron.This approach offers a promising solution for accurately measuring the transport properties of carriers in perovskite.

Opportunities for production and property research of neutron-rich nuclei around N=126 at HIAF

The study of nuclide production and its properties in the N=126 neutron-rich region is prevalent in nuclear physics and astrophysics research.The upcoming High-energy FRagment Separator(HFRS)at the High-Intensity heavy-ion Accelerator Facility(HIAF),an in-flight separator at relativistic energies,is characterized by high beam intensity,large ion-optical acceptance,high magnetic rigidity,and high momentum resolution power.This provides an opportunity to study the production and properties of neutron-rich nuclei around N=126.In this paper,an experimental scheme is proposed to produce neutron-rich nuclei around N=126 and simultaneously measure their mass and lifetime based on the HFRS separator;the feasibility of this scheme is evaluated through simulations.The results show that under the high-resolution optical mode,many new neutron-rich nuclei approaching the r-process abundance peak around A=195 can be produced for the first time,and many nuclei with unknown masses and lifetimes can be produced with high statistics.Using the time-of-flight corrected by the measured dispersive position and energy loss information,the cocktails produced from 208 Pb fragmentation can be unambiguously identified.Moreover,the masses of some neutron-rich nuclei near N=126 can be measured with high precision using the time-of-flight magnetic rigidity technique.This indicates that the HIAF-HFRS facility has the potential for the production and property research of neutron-rich nuclei around N=126,which is of great significance for expanding the chart of nuclides,developing nuclear theories,and understanding the origin of heavy elements in the universe.