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-co...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.展开更多
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...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.展开更多
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 ea...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.展开更多
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 ene...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.展开更多
Room temperature phosphorescence(RTP) is important in both organic electronics and encryption. Despite rapid advances, a universal approach to robust and tunable RTP materials based on amorphous polymers remains a for...Room temperature phosphorescence(RTP) is important in both organic electronics and encryption. Despite rapid advances, a universal approach to robust and tunable RTP materials based on amorphous polymers remains a formidable challenge. Here, we present a strategy that uses three-dimensional(3 D)confinement of carbon dots in a polymer network to achieve ultra-long lifetime phosphorescence. The RTP of the as-obtained materials was not quenched in different polar organic solvents and the lifetime of the RTP was easily tuned by adjusting the amount of crosslinking or varying the drying temperature of the 3 D molecular network. As a demonstration of potential application, as-obtained RTP materials were successfully used to prepare RTP fibres for flexible textiles. As well as bringing to light a fundamental principle for the construction of polymer materials with RTP, we have endowed traditional carbon dots and polymers with fresh features that will expand potential applications.展开更多
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）...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.展开更多
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 ...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.展开更多
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 coupl...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.展开更多
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 ...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.展开更多
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 va...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.展开更多
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 ...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.展开更多
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-PC...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.展开更多
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,...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.展开更多
In the active layer of organic solar cells(OSCs),the lifetime of triplet excitons is one of the decisive factors in the diffusion length and therefore has important impact on the power conversion efficiency of the dev...In the active layer of organic solar cells(OSCs),the lifetime of triplet excitons is one of the decisive factors in the diffusion length and therefore has important impact on the power conversion efficiency of the devices.Herein,we have investigated singlet excited state relaxation dynamics and their triplet exciton lifetimes of two thiophene-coupled perylene diimides(PDI)dyads(2 PDI-Th and fused-2 PDI-Th),in order to provide a unique explanation in depth on their different performances in OSC devices.From the transient absorption(TA)spectra,the singlet excitons of 2 PDI-Th form excimers in the time scale of 1.5 ps.Then the excimers go into the triplet state via intersystem crossing(ISC).In fused-2 PDI-Th,triplet excitons are generated directly from the singlet excited excitons via the efficient ISC.Density functional theory(DFT)calculations further support the formation of excimers.DFT results indicate that 2 PDI-Th exhibits an H-typed molecular configuration which is beneficial to form the excimers,while fused-2 PDITh gives a twisted X-shaped configuration in the optimized ground and excited state.In steady-state emission spectra,2 PDI-Th shows abroad and featureless spectral characteristics of the excimers with a decay time of 840 ps,which is much shorter than those of PDI(5.5 ns)and fused-2 PDI-Th(3.3 ns).The triplet lifetime(67 ms)of fused-2 PDI-Th is factor of 3 longer than that of 2 PDI-Th(22 ms).These results demonstrate that ring-fused structure is an efficient strategy to eliminate excimer formation and prolong the lifetime of triplet excitons,which provides a new insight for design of optoelectronic molecules for high efficiency organic solar cells.展开更多
In this paper we consider a coherent system consisting of n components with independent and identically distributed components. We obtain a mixture representation of the reliability function of the residual lifetime o...In this paper we consider a coherent system consisting of n components with independent and identically distributed components. We obtain a mixture representation of the reliability function of the residual lifetime of living components of a coherent system when the system has failed. Based on the concept of s^gnature, stochastic comparisons on the residual life of two systems with stochastically ordered signatures are conducted.展开更多
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 det...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.展开更多
The lifetime of the 5d6s ^(3)D_(1) clock state in Lu^(+)exhibits a large discrepancy between experimental and theoretical values.To resolve this discrepancy,we perform calculations of the magnetic dipole transition ra...The lifetime of the 5d6s ^(3)D_(1) clock state in Lu^(+)exhibits a large discrepancy between experimental and theoretical values.To resolve this discrepancy,we perform calculations of the magnetic dipole transition rate between the 5d6s ^(3)D_(1) and 6s^(2)^(1)S_(0) states using the multi-configuration Dirac–Hartree–Fock method.The effects of electron correlations,Breit interaction,and quantum electrodynamics(QED)corrections on the transition parameters are analyzed systematically.The calculated 5d6s ^(3)D_(1)–6s^(2)^(1)S_(0) magnetic dipole transition rate,1.69(7)×10^(-6)s^(-1),shows excellent agreement with the experimental measurement.To accurately determine the lifetime of the^(3)D_(1) clock state,the hyperfine-induced electric quadrupole transition rate between the^(3)D_(1) and ground states is also calculated.Furthermore,the rates of various transitions between states in the 5d6s configuration are obtained.The lifetimes of the ^(3)D_(2,3)and ^(1)D_(2) states are consistent with previous theoretical calculations.展开更多
We analyzed quasifission lifetimes of superheavy elements(SHEs)in the atomic number range 104≤Z≤120 and mass number range 243≤A≤301 considering various projectile-target combinations.Nucleusnucleus potentials were...We analyzed quasifission lifetimes of superheavy elements(SHEs)in the atomic number range 104≤Z≤120 and mass number range 243≤A≤301 considering various projectile-target combinations.Nucleusnucleus potentials were evaluated using the nuclear proximity 2010 model,and quasifission barriers were evaluated as the difference between minimum and maximum potentials.The quasifission lifetimes varied from 0.1 zs to 2040 zs,with lifetimes above 1600 zs for_(145)^(249)Rf,_(143)^(248)Db,_(154)^(260)Sg,and_(156)^(263)Hs.The quasifission lifetimes decreased with increasing Z,dropping to 0.1 zs at Z=120.Shorter quasifission lifetimes may contribute to a reduction in production cross-sections from nanobarns to picobarns for elements with Z=104 to Z=118.Furthermore,the impact of angular momentum on quasifission barriers exhibited a decreasing trend as the atomic number increased.The shortest lifetime of 253 zs was observed at Z=120,while longer lifetimes,such as 659 zs for^(64)Ni+^(196)Pt,suggest enhanced stability.The model was validated against data available in literature,generally producing lower values except for34S+186W and^(238)U+^(48)Ca,where significant increases were observed.展开更多
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...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.展开更多
A measurement of the lifetimes of theΩ_(c)^(0)andΞ_(c)^(0)baryons is reported using proton-proton collision data at a centre-of-mass energy of 13 TeV,corresponding to an integrated luminosity of 5.4 fb;collected by ...A measurement of the lifetimes of theΩ_(c)^(0)andΞ_(c)^(0)baryons is reported using proton-proton collision data at a centre-of-mass energy of 13 TeV,corresponding to an integrated luminosity of 5.4 fb;collected by the LHCb experiment.TheΩ_(c)^(0)andΞ_(c)^(0)baryons are produced directly from proton interactions and reconstructed in the p K^(-)K^(+)π^(+)nal state.TheΩ_(c)^(0)lifetime is measured to be 276.5±13.4±4.4±0.7 fs,and theΞ_(c)^(0)lifetime is measured to be 148.0±2.3±2.2±0.2 fs,where the first uncertainty is statistical,the second systematic,and the third due to the uncertainty on the D^(0)lifetime.These results con firm previous LHCb measurements based on semileptonic beauty-hadron decays,which disagree with earlier results of a four times shorterΩ_(c)^(0)lifetime,and provide the single most precise measurement of theΩ_(c)^(0)lifetime.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11874177)。
文摘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.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11874090, 91536106, 61127901, 11404025, and U1530142)the Strategic Priority Research Program of CAS (Grant No. XDB21030100)+1 种基金the Key Research Project of Frontier Science of CAS (Grant No. QYZDB-SSW-JSC004)the West Light Foundation of CAS (Grant No. XAB2018B17)。
文摘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.
文摘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.
文摘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.
基金supported by the National Natural Science Foundation of China (No.31890774)Excellent Young Scholar Sponsorship Program by National Forestry and Grassland Administration of China Funding (No.2019132611)+1 种基金Heilong Jiang Postdoctoral Science Foundation (No.LBH-Z18005)Young Elite Scientists Sponsorship Program by CAST (No.2018QNRC001)。
文摘Room temperature phosphorescence(RTP) is important in both organic electronics and encryption. Despite rapid advances, a universal approach to robust and tunable RTP materials based on amorphous polymers remains a formidable challenge. Here, we present a strategy that uses three-dimensional(3 D)confinement of carbon dots in a polymer network to achieve ultra-long lifetime phosphorescence. The RTP of the as-obtained materials was not quenched in different polar organic solvents and the lifetime of the RTP was easily tuned by adjusting the amount of crosslinking or varying the drying temperature of the 3 D molecular network. As a demonstration of potential application, as-obtained RTP materials were successfully used to prepare RTP fibres for flexible textiles. As well as bringing to light a fundamental principle for the construction of polymer materials with RTP, we have endowed traditional carbon dots and polymers with fresh features that will expand potential applications.
基金Project supported by the National Magnetic Confinement Fusion Science Program of China(Grant No.2010GB104003)the Fundamental Research Funds for the Central Universities,China(Grant Nos.200903369 and 201103255)+1 种基金the Natural Science Foundation of Heilongjiang Province,China(Grant No.QC2011C092)the Program for Young Teacher's Scientific Research in Qiqihar University,China(Grant Nos.2010K-Z05 and 2010K-M31)
文摘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.
基金Project supported by the National Natural Science Foundation of China(Grant No.11174218)
文摘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.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11034003,11074095,and 11274140)the Natural Science Foundation of Heilongjiang Province,China(Grant No.F201335)the Scientific and Technological Research Foundation of Qiqihar,China(Grant No.GYGG-201209-1)
文摘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.
基金supported by the Research Foundation for Higher Level Talents of West Anhui University(Grant No.WGKQ2021005).
文摘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.
基金This work was supported in part by the Institute of Information&communications Technology Planning&Evaluation(IITP)grant funded by the Korea government(MSIT)(No.2018-0-01411,A Micro-Service IoTWare Framework Technology Development for Ultra small IoT Device)in part by 2021 Hongik University Innovation Support program Fund.
文摘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.
基金Project supported by the Research Foundation for Higher Level Talents of West Anhui University(Grant No.WGKQ2021005)。
文摘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.
基金Project supported by Key Area Research and Development Project of Guangdong Province,China(Grant No.2020B010170002)the Science Challenge Project(Grant No.TZ2018003-1-101)+4 种基金the Natural Science Foundation of Fujian Province of China for Distinguished Young Scholars(Grant No.2020J06002)the Science and Technology Project of Fujian Province of China(Grant No.2020I0001)the Fundamental Research Funds for the Central Universities(Grant Nos.20720190049 and 20720190053)the Science and Technology Key Projects of Xiamen(Grant No.3502ZCQ20191001)the National Natural Science Foundation of China(Grant No.51871189)。
文摘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.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10876028,10847007,and 10964010)the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20070736001)
文摘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.
基金the National Natural Science Foundation of China(Nos.21421005,21576040,21776037 and 21875027)the Fundamental Research Funds for the Central Universities(No.DUT19LK05)Supercomputing Center of Dalian University of Technology。
文摘In the active layer of organic solar cells(OSCs),the lifetime of triplet excitons is one of the decisive factors in the diffusion length and therefore has important impact on the power conversion efficiency of the devices.Herein,we have investigated singlet excited state relaxation dynamics and their triplet exciton lifetimes of two thiophene-coupled perylene diimides(PDI)dyads(2 PDI-Th and fused-2 PDI-Th),in order to provide a unique explanation in depth on their different performances in OSC devices.From the transient absorption(TA)spectra,the singlet excitons of 2 PDI-Th form excimers in the time scale of 1.5 ps.Then the excimers go into the triplet state via intersystem crossing(ISC).In fused-2 PDI-Th,triplet excitons are generated directly from the singlet excited excitons via the efficient ISC.Density functional theory(DFT)calculations further support the formation of excimers.DFT results indicate that 2 PDI-Th exhibits an H-typed molecular configuration which is beneficial to form the excimers,while fused-2 PDITh gives a twisted X-shaped configuration in the optimized ground and excited state.In steady-state emission spectra,2 PDI-Th shows abroad and featureless spectral characteristics of the excimers with a decay time of 840 ps,which is much shorter than those of PDI(5.5 ns)and fused-2 PDI-Th(3.3 ns).The triplet lifetime(67 ms)of fused-2 PDI-Th is factor of 3 longer than that of 2 PDI-Th(22 ms).These results demonstrate that ring-fused structure is an efficient strategy to eliminate excimer formation and prolong the lifetime of triplet excitons,which provides a new insight for design of optoelectronic molecules for high efficiency organic solar cells.
基金Supported by the National Natural Science Foundation of China(Grant Nos.1116102871361020)
文摘In this paper we consider a coherent system consisting of n components with independent and identically distributed components. We obtain a mixture representation of the reliability function of the residual lifetime of living components of a coherent system when the system has failed. Based on the concept of s^gnature, stochastic comparisons on the residual life of two systems with stochastically ordered signatures are conducted.
文摘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.
基金supported by the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0300902)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB35010202)+1 种基金the Operation and Maintenance of Major Scientific and Technological Infrastructure of the Chinese Academy of Sciences(GrantNo.2024000014)the Natural Science Foundation of Shaanxi Province(Grant No.2025JC-YBMS-038)。
文摘The lifetime of the 5d6s ^(3)D_(1) clock state in Lu^(+)exhibits a large discrepancy between experimental and theoretical values.To resolve this discrepancy,we perform calculations of the magnetic dipole transition rate between the 5d6s ^(3)D_(1) and 6s^(2)^(1)S_(0) states using the multi-configuration Dirac–Hartree–Fock method.The effects of electron correlations,Breit interaction,and quantum electrodynamics(QED)corrections on the transition parameters are analyzed systematically.The calculated 5d6s ^(3)D_(1)–6s^(2)^(1)S_(0) magnetic dipole transition rate,1.69(7)×10^(-6)s^(-1),shows excellent agreement with the experimental measurement.To accurately determine the lifetime of the^(3)D_(1) clock state,the hyperfine-induced electric quadrupole transition rate between the^(3)D_(1) and ground states is also calculated.Furthermore,the rates of various transitions between states in the 5d6s configuration are obtained.The lifetimes of the ^(3)D_(2,3)and ^(1)D_(2) states are consistent with previous theoretical calculations.
文摘We analyzed quasifission lifetimes of superheavy elements(SHEs)in the atomic number range 104≤Z≤120 and mass number range 243≤A≤301 considering various projectile-target combinations.Nucleusnucleus potentials were evaluated using the nuclear proximity 2010 model,and quasifission barriers were evaluated as the difference between minimum and maximum potentials.The quasifission lifetimes varied from 0.1 zs to 2040 zs,with lifetimes above 1600 zs for_(145)^(249)Rf,_(143)^(248)Db,_(154)^(260)Sg,and_(156)^(263)Hs.The quasifission lifetimes decreased with increasing Z,dropping to 0.1 zs at Z=120.Shorter quasifission lifetimes may contribute to a reduction in production cross-sections from nanobarns to picobarns for elements with Z=104 to Z=118.Furthermore,the impact of angular momentum on quasifission barriers exhibited a decreasing trend as the atomic number increased.The shortest lifetime of 253 zs was observed at Z=120,while longer lifetimes,such as 659 zs for^(64)Ni+^(196)Pt,suggest enhanced stability.The model was validated against data available in literature,generally producing lower values except for34S+186W and^(238)U+^(48)Ca,where significant increases were observed.
基金supported by the Basic Research Foundation of Xi'an University of Architecture and Technology (No.JC0510)the Foundation for Talents of Xi'an University of Architecture and Technology (No.RC0604)the Foundation of Education Department of Shaanxi Province (No.08JK343).
文摘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.
文摘A measurement of the lifetimes of theΩ_(c)^(0)andΞ_(c)^(0)baryons is reported using proton-proton collision data at a centre-of-mass energy of 13 TeV,corresponding to an integrated luminosity of 5.4 fb;collected by the LHCb experiment.TheΩ_(c)^(0)andΞ_(c)^(0)baryons are produced directly from proton interactions and reconstructed in the p K^(-)K^(+)π^(+)nal state.TheΩ_(c)^(0)lifetime is measured to be 276.5±13.4±4.4±0.7 fs,and theΞ_(c)^(0)lifetime is measured to be 148.0±2.3±2.2±0.2 fs,where the first uncertainty is statistical,the second systematic,and the third due to the uncertainty on the D^(0)lifetime.These results con firm previous LHCb measurements based on semileptonic beauty-hadron decays,which disagree with earlier results of a four times shorterΩ_(c)^(0)lifetime,and provide the single most precise measurement of theΩ_(c)^(0)lifetime.
