This paper presents a linearized approach for the controller design of the shape of output probability density functions for general stochastic systems. A square root approximation to an output probability density fun...This paper presents a linearized approach for the controller design of the shape of output probability density functions for general stochastic systems. A square root approximation to an output probability density function is realized by a set of B-spline functions. This generally produces a nonlinear state space model for the weights of the B-spline approximation. A linearized model is therefore obtained and embedded into a performance function that measures the tracking error of the output probability density function with respect to a given distribution. By using this performance function as a Lyapunov function for the closed loop system, a feedback control input has been obtained which guarantees closed loop stability and realizes perfect tracking. The algorithm described in this paper has been tested on a simulated example and desired results have been achieved.展开更多
The cause of the formal difference of p-norm distribution density functions is analyzed, two problems in the deduction of p-norm formulating are improved, and it is proved that two different forms of p-norm distributi...The cause of the formal difference of p-norm distribution density functions is analyzed, two problems in the deduction of p-norm formulating are improved, and it is proved that two different forms of p-norm distribution density functions are equivalent. This work is useful for popularization and application of the p-norm theory to surveying and mapping.展开更多
We study the uncertainties of quantum mechanical observables, quantified by the standard deviation(square root of variance) in Haar-distributed random pure states. We derive analytically the probability density functi...We study the uncertainties of quantum mechanical observables, quantified by the standard deviation(square root of variance) in Haar-distributed random pure states. We derive analytically the probability density functions(PDFs) of the uncertainties of arbitrary qubit observables.Based on these PDFs, the uncertainty regions of the observables are characterized by the support of the PDFs. The state-independent uncertainty relations are then transformed into the optimization problems over uncertainty regions, which opens a new vista for studying stateindependent uncertainty relations. Our results may be generalized to multiple observable cases in higher dimensional spaces.展开更多
The principal resonance of Duffing random external excitation was investigated. oscillator to combined deterministic and The random excitation was taken to be white noise or harmonic with separable random amplitude an...The principal resonance of Duffing random external excitation was investigated. oscillator to combined deterministic and The random excitation was taken to be white noise or harmonic with separable random amplitude and phase. The method of multiple scales was used to determine the equations of modulation of amplitude and phase. The one peak probability density function of each of the two stable stationary solutions was calculated by the linearization method. These two one-peak-density functions were combined using the probability of realization of the two stable stationary solutions to obtain the double peak probability density function. The theoretical analysis are verified by numerical results.展开更多
In molybdenum chemistry,the oxidative addition of o-quinone or 1,2-dicarbonyl compounds to molybdenum has been widely used in Mo-catalyzed C—C bond construction.The carbonyl oxidative addition to Mo(0)or Mo(Ⅱ)is the...In molybdenum chemistry,the oxidative addition of o-quinone or 1,2-dicarbonyl compounds to molybdenum has been widely used in Mo-catalyzed C—C bond construction.The carbonyl oxidative addition to Mo(0)or Mo(Ⅱ)is the critical elementary reaction of molybdenum catalysis.However,the relevant density functional theory(DFT)studies are relatively scarce,especially regarding the rational selection of functionals.In this work,14 functionals were employed to investigate the Mo-catalyzed carbonyl oxidative addition step.A benchmark study was carried out to evaluate their performance in structure optimization and energy calculation.Analyses of mean absolute error(MAE)and mean squared error(MSE)indicated that the B3LYP-D3(BJ),TPSSh,and ωB97X-D functionals exhibited superior performance in structure optimization.Using the DLPNO-CCSD(T)functional as the reference,the M06,M06-L,and MN15-L functionals exhibited good performance for energy calculation based on the structures optimized using the B3LYP-D3(BJ)functional.In particular,MN15-L provided the best performance with the smallest MAE and MSE.展开更多
Understanding the properties of warm dense hydrogen is of key importance for the modeling of compact astrophysical objects and to understand and further optimize inertial confinement fusion applications.The workhorse ...Understanding the properties of warm dense hydrogen is of key importance for the modeling of compact astrophysical objects and to understand and further optimize inertial confinement fusion applications.The workhorse of warm dense matter theory is thermal density functional theory(DFT),which,however,suffers from two limitations:(i)its accuracy can depend on the utilized exchange-correlation functional,which has to be approximated,and(ii)it is generally limited to single-electron properties such as the density distribution.Here,we present a new ansatz combining time-dependent DFT results for the dynamic structure factor S_(ee)(q,ω)with static DFT results for the density response.This allows us to estimate the electron-electron static structure factor S_(ee)(q)of warm dense hydrogen with high accuracy over a broad range of densities and temperatures.In addition to its value for the study of warm dense matter,our work opens up new avenues for the future study of electronic correlations exclusively within the framework of DFT for a host of applications.展开更多
This study investigated the suppressive effects of Armoracia rusticana(AR)and its three main glucosinolates on both free and bound heterocyclic amines(HAs),along with their mechanisms of free radical quenching using d...This study investigated the suppressive effects of Armoracia rusticana(AR)and its three main glucosinolates on both free and bound heterocyclic amines(HAs),along with their mechanisms of free radical quenching using density functional theory.Fish patties were supplemented with varying concentrations of AR(0.5%‒1.5%)and glucosinolates(0.005%‒0.015%),showing a dose-dependent inhibition of HAs and concurrent elimination of free radicals and HAs intermediates.Glucobrassicin demonstrated the highest reactivity,which was verified by frontier orbit analysis and conceptual density functional parameters,consistent with experimental findings.Furthermore,the O-H bond connected to the sulfur atom of glucobrassicin possessed the smallest bond dissociation enthalpy(BDE)value,which indicated that this particular hydrogen atom is most susceptible to react with free radicals.Overall,AR and its glucosinolates,especially glucobrassicin,show promise as natural additives for improving food safety and quality.展开更多
The fractional quantum Hall effect remains a captivating area in condensed matter physics,characterized by strongly correlated topological order,which manifests as fractionalized excitations and anyonic statistics.Num...The fractional quantum Hall effect remains a captivating area in condensed matter physics,characterized by strongly correlated topological order,which manifests as fractionalized excitations and anyonic statistics.Numerical simulations,such as exact diagonalization,density matrix renormalization groups,matrix product states,and Monte Carlo methods are essential for examining the properties of strongly correlated systems.Recently,density functional theory has been employed in this field within the framework of composite fermion theory.This paper systematically evaluates how density functional theory approaches have addressed fundamental challenges in fractional quantum Hall systems,including ground state and low-energy excitations.Special attention is given to the insights provided by density functional theory regarding composite fermion behavior,edge effects,and the nature of fractional charge and magnetoroton excitations.The discussion critically examines both the advantages and limitations of these approaches,while highlighting the productive interplay between numerical simulations and theoretical models.Future directions are explored,particularly the promising potential of time-dependent density functional theory for modeling non-equilibrium dynamics in quantum Hall systems.展开更多
As a novel class of purely organic fluores-cent materials,multiple resonance thermal-ly activated delayed fluorescence(MR-TADF)compounds hold significant promise for next-generation display technologies.The efficiency...As a novel class of purely organic fluores-cent materials,multiple resonance thermal-ly activated delayed fluorescence(MR-TADF)compounds hold significant promise for next-generation display technologies.The efficiency of exciton utilization and the overall performance of organic light-emit-ting devices are closely linked to the singlet-triplet energy gap(ΔE_(ST))of MR-TADF emitters.Identifying an economic and accu-rate theoretical approach to predictΔE_(ST)would be beneficial for high-throughput screening and facilitate the inverse design of MR-TADF molecules.In this study,we evaluated the S_(1)state energy(E(S_(1))),T_(1)state ener-gy(E(T_(1))),andΔE_(ST)using three different physical interpretations:adiabatic excitation ener-gy,vertical absorption energy,and vertical emission energy.We employed the time-depen-dent density functional theory(TDDFT)and delta self-consistent field(ΔSCF)methods to calculate E(S_(1)),E(T_(1)),andΔE_(ST)for 20 MR-TADF molecules reported in the literature.We compared these calculated values with experimental data obtained from fluorescence spec-troscopy at room-temperature(or 77 K)and phosphorescence spectroscopy conducted at 77 K.Our findings indicate that the vertical absorption energy at the S0 state minimum,deter-mined by theΔSCF method,accurately predicts the S_(1)state energy.Similarly,the vertical absorption energy at the S0 state minimum,calculated using the TDDFT method,effectively predicts the T_(1)state energy.TheΔE_(ST)derived from the difference between these two excita-tion energies exhibited the smallest mean absolute error of only 0.039 eV compared to the ex-perimental values.This combination represents the most accurate and cost-effective method reported to date for predicting theΔE_(ST)of MR-TADF molecules,and can be integrated into AI-driven inverse design workflows for new emitters.展开更多
The pleiotropic functions of circulating high density lipoprotein（HDL） on peripheral vascular health are well established. HDL plays a pivotal role in reverse cholesterol transport and is also known to suppress infl...The pleiotropic functions of circulating high density lipoprotein（HDL） on peripheral vascular health are well established. HDL plays a pivotal role in reverse cholesterol transport and is also known to suppress inflammation,endothelial activation and apoptosis in peripheral vessels. Although not expressed in the central nervous system, HDL has nevertheless emerged as a potential resilience factor for dementia in multiple epidemiological studies. Animal model data specifically support a role for HDL in attenuating the accumulation of P-amyloid within cerebral vessels concomitant with reduced neuroinflammation and improved cognitive performance. As the vascular contributions to dementia are increasingly appreciated, this review seeks to summarize recent literature focused on the vasoprotective properties of HDL that may extend to cerebral vessels, discuss potential roles of HDL in dementia relative to brainderived lipoproteins, identify gaps in current knowledge, and highlight new opportunities for research and discovery.展开更多
We propose to approximate the conditional density function of a random variable Y given a dependent random d-vector X by that of Y given θ^τX, where the unit vector θ is selected such that the average Kullback-Leib...We propose to approximate the conditional density function of a random variable Y given a dependent random d-vector X by that of Y given θ^τX, where the unit vector θ is selected such that the average Kullback-Leibler discrepancy distance between the two conditional density functions obtains the minimum. Our approach is nonparametric as far as the estimation of the conditional density functions is concerned. We have shown that this nonparametric estimator is asymptotically adaptive to the unknown index θ in the sense that the first order asymptotic mean squared error of the estimator is the same as that when θ was known. The proposed method is illustrated using both simulated and real-data examples.展开更多
Suppose that Z1 , Z2,’’’ Zn are independent normal random variables with common meanμ and variance σ2. Then S2 and have distribution andtn-1 distribution respectively. If the normal assumption fails, there will b...Suppose that Z1 , Z2,’’’ Zn are independent normal random variables with common meanμ and variance σ2. Then S2 and have distribution andtn-1 distribution respectively. If the normal assumption fails, there will be the remaindersof the distribution functions and density functions. This paper gives the direct expansions ofdistribution functions and density functions of S2 alld T up to o(n-1). They are more intuitiveand convenient than usual Edgeworth expansions.展开更多
We have examined the theoretical implications of combining two main and three auxiliary ligands to form several Ir(Ⅲ)complexes featuring a transition metal as their core atom to identify some appropriate organic ligh...We have examined the theoretical implications of combining two main and three auxiliary ligands to form several Ir(Ⅲ)complexes featuring a transition metal as their core atom to identify some appropriate organic lightemitting diode(OLED)materials.By utilizing electronic structure,frontier molecular orbitals,minimum single-line absorption,triplet excited states,and emission spectral data derived from the density functional theory,the usefulness of these Ir(Ⅲ)complexes,including(piq)_(2)Ir(acac),(piq)_(2)Ir(tmd),(piq)_(2)Ir(tpip),(fpiq)_(2)Ir(acac),(fpiq)_(2)Ir(tmd),and(fpiq)_(2)Ir(tpip),in OLEDs was examined,where piq=1-phenylisoquinoline,fpiq=1-(4-fluorophenyl)isoquinoline,acac=(3Z)-4-hydroxypent-3-en-2-one,tmd=(4Z)-5-hydroxy-2,2,6,6-tetramethylhept-4-en-3-one,and tpip=tetraphenylimido-diphosphonate.These complexes all have low-efficiency roll-off properties,especially(fpiq)_(2)Ir(tpip).Some researchers have successfully synthesized complexes extremely similar to(piq)_(2)Ir(acac)through the Suzuki-Miyaura coupling reaction.展开更多
By adopting stochastic density functional theory(SDFT)and mixed stochastic-deterministic density functional theory(MDFT)methods,we perform first-principles calculations to predict the shock Hugoniot curves of boron(pr...By adopting stochastic density functional theory(SDFT)and mixed stochastic-deterministic density functional theory(MDFT)methods,we perform first-principles calculations to predict the shock Hugoniot curves of boron(pressure P=7.9×10^(3)-1.6×10^(6) GPa and temperature T=25-2800 eV),silicon(P=2.6×10^(3)-7.9×10^(5) GPa and T=21.5-1393 eV),and aluminum(P=5.2×10^(3)-9.0×10^(5) GPa and T=25-1393 eV)over wide ranges of pressure and temperature.In particular,we systematically investigate the impact of different cutoff radii in norm-conserving pseudopotentials on the calculated properties at elevated temperatures,such as pressure,ionization energy,and equation of state.By comparing the SDFT and MDFT results with those of other first-principles methods,such as extended first-principles molecular dynamics and path integral Monte Carlo methods,we find that the SDFT and MDFT methods show satisfactory precision,which advances our understanding of first-principles methods when applied to studies of matter at extremely high pressures and temperatures.展开更多
A sparsely introduced basal intrinsic 2-type stacking fault(I_(2)-SF)with a dense segregation of clusters(cluster-arranged layer;CAL)inα-Mg exerts a sufficient strengthening effect with a reduced content of additive ...A sparsely introduced basal intrinsic 2-type stacking fault(I_(2)-SF)with a dense segregation of clusters(cluster-arranged layer;CAL)inα-Mg exerts a sufficient strengthening effect with a reduced content of additive elements.Moreover,the dynamic nucleation and growth of CALs during deformation largely improves the creep resistance.This paper analyzes the cosegregation behaviors of yttrium(Y)and zinc(Zn)atoms at an I_(2)-SF in bulk and at basal edge dislocations using density functional theory calculations.We also study the modification of the generalized stacking-fault energy(GSFE)curves associated with the cosegregation.The segregation energies of Y and Zn atoms in the I_(2)-SF are relatively small during the initial segregation of a cluster,but increases stepwise as the cluster grows.After introducing Y and Zn atoms in the I_(2)-SF in an energetically stable order,we obtain an L1_(2)-type cluster resembling that reported in the literature.Small structural changes driven by vacancy diffusion produce an exact L1_(2)-type cluster.Meanwhile,the core of the Shockley partial dislocation generates sufficient segregation energy for cluster nucleation.Migration of the Shockley partial dislocation and expansion of the I_(2)-SF part are observed at a specific cluster size.The migration is triggered by a large modification of the GSFE curve and destabilization of the hexagonal close-packed stacking(hcp)by the segregated atoms.At this point,the cluster has reached sufficient size and continues to follow the growth in the I_(2)-SF part.According to our findings,the CAL at elevated temperature is formed through repeated synchronized behavior of cluster nucleation at the Shockley partial dislocation,dislocation migration triggered by the destabilized hcp stacking,and following of cluster growth in the I_(2)-SF part of the dislocation.展开更多
Metal-organic framework(MOF) has been widely applied in photocatalysis, which is significant for addressing energy crises and environmental issues. Based on density functional theory calculations,the performances of C...Metal-organic framework(MOF) has been widely applied in photocatalysis, which is significant for addressing energy crises and environmental issues. Based on density functional theory calculations,the performances of Cu-BTC, a copper-based MOF, and its derivatives Cu TM-BTC via the substitution of transition metal(TM) elements at the Cu site for photocatalytic overall water splitting(POWS) have been studied. POWS of Cu-BTC suffers from the sluggish hydrogen evolution reaction due to the large overpotential of 2.02 V and limited solar utilization due to a wide HOMO-LUMO gap of 4.11 e V. Via TM substitution, the HOMO-LUMO gap narrows but still satisfies the redox potentials when taken 3d-TM of Cr, Fe, Co or Ni, 4d-TM of Rh or Pd, or 5d-TM of Re or Pt into consideration, benefiting for the light absorption. Furthermore, Cr and Re could serve as active sites for hydrogen evolution with remarkably lowered overpotentials of 0.79 V and 0.28 V, respectively;similarly, oxygen evolution activities could be enhanced by Fe, Co and Rh because of their reduced overpotentials which are less than 0.5 V. Therefore,our findings pave guidance for designing Cu-BTC derivatives in overall water splitting.展开更多
Ab initio modeling of dynamic structure factors(DSF)and related density response properties in the warm dense matter(WDM)regime is a challenging computational task.The DSF,convolved with a probing X-ray beam and instr...Ab initio modeling of dynamic structure factors(DSF)and related density response properties in the warm dense matter(WDM)regime is a challenging computational task.The DSF,convolved with a probing X-ray beam and instrument function,is measured in X-ray Thom-son scattering(XRTS)experiments,which allow the study of electronic structure properties at the microscopic level.Among the various ab initio methods,linear-response time-dependent density-functional theory(LR-TDDFT)is a key framework for simulating the DSF.The standard approach in LR-TDDFT for computing the DSF relies on the orbital representation.A significant drawback of this method is the unfavorable scaling of the number of required empty bands as the wavenumber increases,making LR-TDDFT impractical for modeling XRTS measurements over large energy scales,such as in backward scattering geometry.In this work,we consider and test an alternative approach to LR-TDDFT that employs the Liouville–Lanczos(LL)method for simulating the DSF of WDM.This approach does not require empty states and allows the DSF at large momentum transfer values and over a broad frequency range to be accessed.We compare the results obtained from the LL method with those from the solution of Dyson’s equation using the standard LR-TDDFT within the projector augmented-wave formalism for isochorically heated aluminum and warm dense hydrogen.Additionally,we utilize exact path integral Monte Carlo results for the imaginary-time density-density correlation function(ITCF)of warm dense hydrogen to rigorously benchmark the LL approach.We discuss the application of the LL method for calculating DSFs and ITCFs at different wavenumbers,the effects of pseudopotentials,and the role of Lorentzian smearing.The successful validation of the LL method under WDM conditions makes it a valuable addition to the ab initio simulation landscape,supporting experimental efforts and advancing WDM theory.展开更多
Strategic design and synergistic interactions between the electrodes and electroactive materials profoundly influence the energy storage efficiency of supercapacitor devices. Herein, we present the interfacial enginee...Strategic design and synergistic interactions between the electrodes and electroactive materials profoundly influence the energy storage efficiency of supercapacitor devices. Herein, we present the interfacial engineering of CoMoS_(4)-NiS_(2) with a well-defined construction of amorphous/crystalline hetero-phases deposited on carbon cloth using a hydrothermal technique. The optimal in-situ growth of CoMoS_(4)-NiS_(2)@CFC boasts an impressive areal capacity of 1341 mC cm^(-2) and retains ∼91 % capacity after 5000 cycles, attributed to the synergy effect and improved conductivity of multi-metallic sulfide ions over the CFC substrate. Density functional theory (DFT) reveals the metallic nature of CoMoS_(4)-NiS_(2)@CFC and favorable OH- ion adsorption energy of -4.35 eV, enhancing its charge storage capabilities. Furthermore, a hybrid supercapacitor (HSC) and Pouch HSC are assembled utilizing the CoMoS_(4)-NiS_(2)@CFC as a positrode and marine waste jellyfish-derived AC as a negatrode with an aqueous electrolyte. The HSC and PHSC demonstrate superior specific energies of 51.99 and 58.4 W h kg^(-1), respectively, along with corresponding specific powers of 800 and 780 W kg^(-1), maintaining robust stability of ∼90 % stability over 10000 cycles. Additionally, the HSC and PHSC have successfully illuminated several light-emitting diodes (LEDs) demonstrating superior energy storage performance. This work advances the design of hetero-phase multi-metal sulfides, paving the way for high-performance supercapacitor devices.展开更多
Localized corrosion of 304 stainless steel being the significant parts of Starship rocket seriously threatens the long-term service of such aerospace equipment.Scanning electron microscopy,in situ instruments combinin...Localized corrosion of 304 stainless steel being the significant parts of Starship rocket seriously threatens the long-term service of such aerospace equipment.Scanning electron microscopy,in situ instruments combining electrochemical workstation and Raman spectroscopy,and Density Dunctional Theory(DFT)calculations were employed.The surface morphologies,alloying elements,molecular fingerprint Raman evidence and theoretical mechanism for the localized corrosion of 304 stainless steel during the electrochemical polarization in the mixture solutions containing 0.5 mol/L H_(2)SO_(4) and 2,2'-bipyridine(bipy)with concentrations of 0.001,0.010,0.100 mol/L were discussed.In comparison,the presence of bipy up to 0.100 mol/L in such mixture solutions displayed the neglectable effect on the Fe(Ⅱ)/Fe(Ⅲ)reaction in the polarization process.Raman vibrational frequency around 1492 cm^(-1)was the evidence of pink color appearance due to the formation of[Fe^(Ⅱ)(bipy)_(3)]^(2+).Raman and DFT indicated the yellow color emergence due to the presence ofμ-O-[Fe^(Ⅲ)(bipy)_(2)(H_(2)O)]_(2)^(4+)due to the oxidation reaction of[Fe^(Ⅱ)(bipy)_(3)]^(2+)with H_(2)O_(2) oxidant,and the dimerization of[Fe^(Ⅲ)(bipy)_(3)]^(3+),Furthermore,a quantitative model between[Fe^(Ⅱ)(bipy)_(3)]^(2+)concentration and Raman intensity at 1492 cm^(-1) has been built up.Two linear functions were revealed when[Fe^(Ⅱ)(bipy)_(3)]^(2+)concentrations were at 0-0.002 mol/L and 0.002-0.004 mol/L and a concentration error of less than 5%was evidenced in comparison with that investigated by the inductively coupled plasma.The proposed passivation mechanism and quantitative concentration model of 304 stainless steel have certain significance for its corrosion protection andcorrosionevaluation.展开更多
Nuclear masses play a crucial role in both nuclear physics and astrophysics,driving sustained efforts toward precise experi-mental determination and reliable theoretical predictions.In this study,we compiled the newly...Nuclear masses play a crucial role in both nuclear physics and astrophysics,driving sustained efforts toward precise experi-mental determination and reliable theoretical predictions.In this study,we compiled the newly measured masses for 296 nuclides from 40 references published between 2021 and 2024,subsequent to the release of the latest atomic mass evalu-ation.These data were used to benchmark the performance of several relativistic and nonrelativistic density functionals,including PC-PK1,TMA,SLy4,SV-min,UNEDF1,and the recently proposed PC-L3R.The results for PC-PK1 and PC-L3R were obtained using the state-of-the-art deformed relativistic Hartree-Bogoliubov theory in continuum(DRHBc),whereas the others were adopted from the existing literature.It was found that the DRHBc calculations with PC-PK1 and PC-L3R achieved an accuracy better than 1.5 MeV,outperforming the other functionals,which all exhibited root-mean-square devia-tions exceeding 2 MeV.The odd-even effects and isospin dependence in these theoretical descriptions were examined.The PC-PK1 and PC-L3R descriptions were qualitatively similar,exhibiting robust isospin dependence along the isotopic chains.Finally,a quantitative comparison between the PC-PK1 and PC-L3R results is presented,with the largest discrepancies analyzed in terms of the potential energy curves from the constrained DRHBc calculations.展开更多
文摘This paper presents a linearized approach for the controller design of the shape of output probability density functions for general stochastic systems. A square root approximation to an output probability density function is realized by a set of B-spline functions. This generally produces a nonlinear state space model for the weights of the B-spline approximation. A linearized model is therefore obtained and embedded into a performance function that measures the tracking error of the output probability density function with respect to a given distribution. By using this performance function as a Lyapunov function for the closed loop system, a feedback control input has been obtained which guarantees closed loop stability and realizes perfect tracking. The algorithm described in this paper has been tested on a simulated example and desired results have been achieved.
基金Supported by Scientific Research Fund of Hunan Province Education Department (No.03C483) .
文摘The cause of the formal difference of p-norm distribution density functions is analyzed, two problems in the deduction of p-norm formulating are improved, and it is proved that two different forms of p-norm distribution density functions are equivalent. This work is useful for popularization and application of the p-norm theory to surveying and mapping.
基金supported by the NSF of China under Grant Nos.11971140,12075159,and 12171044Beijing Natural Science Foundation(Z190005)+1 种基金the Academician Innovation Platform of Hainan Province,and Academy for Multidisciplinary Studies,Capital Normal Universityfunded by Natural Science Foundations of Hubei Province Grant No.2020CFB538。
文摘We study the uncertainties of quantum mechanical observables, quantified by the standard deviation(square root of variance) in Haar-distributed random pure states. We derive analytically the probability density functions(PDFs) of the uncertainties of arbitrary qubit observables.Based on these PDFs, the uncertainty regions of the observables are characterized by the support of the PDFs. The state-independent uncertainty relations are then transformed into the optimization problems over uncertainty regions, which opens a new vista for studying stateindependent uncertainty relations. Our results may be generalized to multiple observable cases in higher dimensional spaces.
基金Project supported by the National Natural Science Foundation of China (Key Program) (No.10332030)the Natural Science Foundation of Guangdong Province of China (No.04011640)
文摘The principal resonance of Duffing random external excitation was investigated. oscillator to combined deterministic and The random excitation was taken to be white noise or harmonic with separable random amplitude and phase. The method of multiple scales was used to determine the equations of modulation of amplitude and phase. The one peak probability density function of each of the two stable stationary solutions was calculated by the linearization method. These two one-peak-density functions were combined using the probability of realization of the two stable stationary solutions to obtain the double peak probability density function. The theoretical analysis are verified by numerical results.
基金Project supported by the Fundamental Research Funds for the Central Universities(No.2042025kf0052)。
文摘In molybdenum chemistry,the oxidative addition of o-quinone or 1,2-dicarbonyl compounds to molybdenum has been widely used in Mo-catalyzed C—C bond construction.The carbonyl oxidative addition to Mo(0)or Mo(Ⅱ)is the critical elementary reaction of molybdenum catalysis.However,the relevant density functional theory(DFT)studies are relatively scarce,especially regarding the rational selection of functionals.In this work,14 functionals were employed to investigate the Mo-catalyzed carbonyl oxidative addition step.A benchmark study was carried out to evaluate their performance in structure optimization and energy calculation.Analyses of mean absolute error(MAE)and mean squared error(MSE)indicated that the B3LYP-D3(BJ),TPSSh,and ωB97X-D functionals exhibited superior performance in structure optimization.Using the DLPNO-CCSD(T)functional as the reference,the M06,M06-L,and MN15-L functionals exhibited good performance for energy calculation based on the structures optimized using the B3LYP-D3(BJ)functional.In particular,MN15-L provided the best performance with the smallest MAE and MSE.
基金partially supported by the Center for Advanced Systems Understanding (CASUS), financed by Germany’s Federal Ministry of Education and Research and the Saxon State Government out of the State Budget approved by the Saxon State Parliamentthe European Union’s Just Transition Fund (JTF) within the project Röntgenlaser Optimierung der Laserfusion (ROLF), Contract No. 5086999001, co-financed by the Saxon State Government out of the State Budget approved by the Saxon State Parliament+3 种基金the European Research Council (ERC) under the European Union’s Horizon 2022 Research and Innovation Programme (Grant Agreement No. 101076233, “PREXTREME”)Computations were performed on a Bull Cluster at the Center for Information Services and High-Performance Computing (ZIH) at Technische Universität Dresden and at the Norddeutscher Verbund für Hoch- und Höchstleistungsrechnen (HLRN) under Grant No. mvp00024support by the National Natural Science Foundation of China under Grant No. 12274171support by the Advanced Materials–National Science and Technology Major Project (Grant No. 2024ZD0606900)
文摘Understanding the properties of warm dense hydrogen is of key importance for the modeling of compact astrophysical objects and to understand and further optimize inertial confinement fusion applications.The workhorse of warm dense matter theory is thermal density functional theory(DFT),which,however,suffers from two limitations:(i)its accuracy can depend on the utilized exchange-correlation functional,which has to be approximated,and(ii)it is generally limited to single-electron properties such as the density distribution.Here,we present a new ansatz combining time-dependent DFT results for the dynamic structure factor S_(ee)(q,ω)with static DFT results for the density response.This allows us to estimate the electron-electron static structure factor S_(ee)(q)of warm dense hydrogen with high accuracy over a broad range of densities and temperatures.In addition to its value for the study of warm dense matter,our work opens up new avenues for the future study of electronic correlations exclusively within the framework of DFT for a host of applications.
基金supported by the National Natural Science Foundation of China(32302258,32172317)the Science and Technology Innovation Program of Hunan Province(2024RC3185)+1 种基金Hunan Provincial Natural Science Foundation of China(2023JJ40317)Changsha Municipal Natural Science Foundation(kq2202223).
文摘This study investigated the suppressive effects of Armoracia rusticana(AR)and its three main glucosinolates on both free and bound heterocyclic amines(HAs),along with their mechanisms of free radical quenching using density functional theory.Fish patties were supplemented with varying concentrations of AR(0.5%‒1.5%)and glucosinolates(0.005%‒0.015%),showing a dose-dependent inhibition of HAs and concurrent elimination of free radicals and HAs intermediates.Glucobrassicin demonstrated the highest reactivity,which was verified by frontier orbit analysis and conceptual density functional parameters,consistent with experimental findings.Furthermore,the O-H bond connected to the sulfur atom of glucobrassicin possessed the smallest bond dissociation enthalpy(BDE)value,which indicated that this particular hydrogen atom is most susceptible to react with free radicals.Overall,AR and its glucosinolates,especially glucobrassicin,show promise as natural additives for improving food safety and quality.
基金supported by National Natural Science Foundation of China under Grant Nos.12474140 and 12347101supported by National Natural Science Foundation of China under Grant No.12204432+1 种基金supported by the graduate research and innovation foundation of Chongqing,China under Grant No.CYB25066the inaugural Doctoral Student Special Project of the China Association for Science and Technology Young Talents Lifting Program(2024)。
文摘The fractional quantum Hall effect remains a captivating area in condensed matter physics,characterized by strongly correlated topological order,which manifests as fractionalized excitations and anyonic statistics.Numerical simulations,such as exact diagonalization,density matrix renormalization groups,matrix product states,and Monte Carlo methods are essential for examining the properties of strongly correlated systems.Recently,density functional theory has been employed in this field within the framework of composite fermion theory.This paper systematically evaluates how density functional theory approaches have addressed fundamental challenges in fractional quantum Hall systems,including ground state and low-energy excitations.Special attention is given to the insights provided by density functional theory regarding composite fermion behavior,edge effects,and the nature of fractional charge and magnetoroton excitations.The discussion critically examines both the advantages and limitations of these approaches,while highlighting the productive interplay between numerical simulations and theoretical models.Future directions are explored,particularly the promising potential of time-dependent density functional theory for modeling non-equilibrium dynamics in quantum Hall systems.
基金support provided by the National Natural Science Foundation of China(No.22273043).
文摘As a novel class of purely organic fluores-cent materials,multiple resonance thermal-ly activated delayed fluorescence(MR-TADF)compounds hold significant promise for next-generation display technologies.The efficiency of exciton utilization and the overall performance of organic light-emit-ting devices are closely linked to the singlet-triplet energy gap(ΔE_(ST))of MR-TADF emitters.Identifying an economic and accu-rate theoretical approach to predictΔE_(ST)would be beneficial for high-throughput screening and facilitate the inverse design of MR-TADF molecules.In this study,we evaluated the S_(1)state energy(E(S_(1))),T_(1)state ener-gy(E(T_(1))),andΔE_(ST)using three different physical interpretations:adiabatic excitation ener-gy,vertical absorption energy,and vertical emission energy.We employed the time-depen-dent density functional theory(TDDFT)and delta self-consistent field(ΔSCF)methods to calculate E(S_(1)),E(T_(1)),andΔE_(ST)for 20 MR-TADF molecules reported in the literature.We compared these calculated values with experimental data obtained from fluorescence spec-troscopy at room-temperature(or 77 K)and phosphorescence spectroscopy conducted at 77 K.Our findings indicate that the vertical absorption energy at the S0 state minimum,deter-mined by theΔSCF method,accurately predicts the S_(1)state energy.Similarly,the vertical absorption energy at the S0 state minimum,calculated using the TDDFT method,effectively predicts the T_(1)state energy.TheΔE_(ST)derived from the difference between these two excita-tion energies exhibited the smallest mean absolute error of only 0.039 eV compared to the ex-perimental values.This combination represents the most accurate and cost-effective method reported to date for predicting theΔE_(ST)of MR-TADF molecules,and can be integrated into AI-driven inverse design workflows for new emitters.
文摘The pleiotropic functions of circulating high density lipoprotein（HDL） on peripheral vascular health are well established. HDL plays a pivotal role in reverse cholesterol transport and is also known to suppress inflammation,endothelial activation and apoptosis in peripheral vessels. Although not expressed in the central nervous system, HDL has nevertheless emerged as a potential resilience factor for dementia in multiple epidemiological studies. Animal model data specifically support a role for HDL in attenuating the accumulation of P-amyloid within cerebral vessels concomitant with reduced neuroinflammation and improved cognitive performance. As the vascular contributions to dementia are increasingly appreciated, this review seeks to summarize recent literature focused on the vasoprotective properties of HDL that may extend to cerebral vessels, discuss potential roles of HDL in dementia relative to brainderived lipoproteins, identify gaps in current knowledge, and highlight new opportunities for research and discovery.
基金supported by US National Science Foundation grant DMS-0704337 National Natural Science Foundation of China(No.10628104)supported by an EPSRC research grant EP/C549058/1
文摘We propose to approximate the conditional density function of a random variable Y given a dependent random d-vector X by that of Y given θ^τX, where the unit vector θ is selected such that the average Kullback-Leibler discrepancy distance between the two conditional density functions obtains the minimum. Our approach is nonparametric as far as the estimation of the conditional density functions is concerned. We have shown that this nonparametric estimator is asymptotically adaptive to the unknown index θ in the sense that the first order asymptotic mean squared error of the estimator is the same as that when θ was known. The proposed method is illustrated using both simulated and real-data examples.
文摘Suppose that Z1 , Z2,’’’ Zn are independent normal random variables with common meanμ and variance σ2. Then S2 and have distribution andtn-1 distribution respectively. If the normal assumption fails, there will be the remaindersof the distribution functions and density functions. This paper gives the direct expansions ofdistribution functions and density functions of S2 alld T up to o(n-1). They are more intuitiveand convenient than usual Edgeworth expansions.
文摘We have examined the theoretical implications of combining two main and three auxiliary ligands to form several Ir(Ⅲ)complexes featuring a transition metal as their core atom to identify some appropriate organic lightemitting diode(OLED)materials.By utilizing electronic structure,frontier molecular orbitals,minimum single-line absorption,triplet excited states,and emission spectral data derived from the density functional theory,the usefulness of these Ir(Ⅲ)complexes,including(piq)_(2)Ir(acac),(piq)_(2)Ir(tmd),(piq)_(2)Ir(tpip),(fpiq)_(2)Ir(acac),(fpiq)_(2)Ir(tmd),and(fpiq)_(2)Ir(tpip),in OLEDs was examined,where piq=1-phenylisoquinoline,fpiq=1-(4-fluorophenyl)isoquinoline,acac=(3Z)-4-hydroxypent-3-en-2-one,tmd=(4Z)-5-hydroxy-2,2,6,6-tetramethylhept-4-en-3-one,and tpip=tetraphenylimido-diphosphonate.These complexes all have low-efficiency roll-off properties,especially(fpiq)_(2)Ir(tpip).Some researchers have successfully synthesized complexes extremely similar to(piq)_(2)Ir(acac)through the Suzuki-Miyaura coupling reaction.
基金supported by the National Key R&D Program of China under Grant No.2025YFB3003603the National Natural Science Foundation of China under Grant Nos.12135002 and 12105209.
文摘By adopting stochastic density functional theory(SDFT)and mixed stochastic-deterministic density functional theory(MDFT)methods,we perform first-principles calculations to predict the shock Hugoniot curves of boron(pressure P=7.9×10^(3)-1.6×10^(6) GPa and temperature T=25-2800 eV),silicon(P=2.6×10^(3)-7.9×10^(5) GPa and T=21.5-1393 eV),and aluminum(P=5.2×10^(3)-9.0×10^(5) GPa and T=25-1393 eV)over wide ranges of pressure and temperature.In particular,we systematically investigate the impact of different cutoff radii in norm-conserving pseudopotentials on the calculated properties at elevated temperatures,such as pressure,ionization energy,and equation of state.By comparing the SDFT and MDFT results with those of other first-principles methods,such as extended first-principles molecular dynamics and path integral Monte Carlo methods,we find that the SDFT and MDFT methods show satisfactory precision,which advances our understanding of first-principles methods when applied to studies of matter at extremely high pressures and temperatures.
基金supported by the Japan Science and Technology Agency(JST),CREST(grant number JapanJPR2094)。
文摘A sparsely introduced basal intrinsic 2-type stacking fault(I_(2)-SF)with a dense segregation of clusters(cluster-arranged layer;CAL)inα-Mg exerts a sufficient strengthening effect with a reduced content of additive elements.Moreover,the dynamic nucleation and growth of CALs during deformation largely improves the creep resistance.This paper analyzes the cosegregation behaviors of yttrium(Y)and zinc(Zn)atoms at an I_(2)-SF in bulk and at basal edge dislocations using density functional theory calculations.We also study the modification of the generalized stacking-fault energy(GSFE)curves associated with the cosegregation.The segregation energies of Y and Zn atoms in the I_(2)-SF are relatively small during the initial segregation of a cluster,but increases stepwise as the cluster grows.After introducing Y and Zn atoms in the I_(2)-SF in an energetically stable order,we obtain an L1_(2)-type cluster resembling that reported in the literature.Small structural changes driven by vacancy diffusion produce an exact L1_(2)-type cluster.Meanwhile,the core of the Shockley partial dislocation generates sufficient segregation energy for cluster nucleation.Migration of the Shockley partial dislocation and expansion of the I_(2)-SF part are observed at a specific cluster size.The migration is triggered by a large modification of the GSFE curve and destabilization of the hexagonal close-packed stacking(hcp)by the segregated atoms.At this point,the cluster has reached sufficient size and continues to follow the growth in the I_(2)-SF part.According to our findings,the CAL at elevated temperature is formed through repeated synchronized behavior of cluster nucleation at the Shockley partial dislocation,dislocation migration triggered by the destabilized hcp stacking,and following of cluster growth in the I_(2)-SF part of the dislocation.
基金the financial support from National Natural Science Foundation of China (No. 21503097)Postgraduate Research & Practice Innovation Program of Jiangsu Province (No. KYCX23_3905)。
文摘Metal-organic framework(MOF) has been widely applied in photocatalysis, which is significant for addressing energy crises and environmental issues. Based on density functional theory calculations,the performances of Cu-BTC, a copper-based MOF, and its derivatives Cu TM-BTC via the substitution of transition metal(TM) elements at the Cu site for photocatalytic overall water splitting(POWS) have been studied. POWS of Cu-BTC suffers from the sluggish hydrogen evolution reaction due to the large overpotential of 2.02 V and limited solar utilization due to a wide HOMO-LUMO gap of 4.11 e V. Via TM substitution, the HOMO-LUMO gap narrows but still satisfies the redox potentials when taken 3d-TM of Cr, Fe, Co or Ni, 4d-TM of Rh or Pd, or 5d-TM of Re or Pt into consideration, benefiting for the light absorption. Furthermore, Cr and Re could serve as active sites for hydrogen evolution with remarkably lowered overpotentials of 0.79 V and 0.28 V, respectively;similarly, oxygen evolution activities could be enhanced by Fe, Co and Rh because of their reduced overpotentials which are less than 0.5 V. Therefore,our findings pave guidance for designing Cu-BTC derivatives in overall water splitting.
基金supported by the Center for Advanced Systems Understanding(CASUS),financed by Germany’s Federal Ministry of Education and Research(BMBF)and the Saxon State Government out of the State Budget approved by the Saxon State Parliamentfunding from the European Research Council(ERC)under the European Union’s Horizon 2022 research and innovation programme(Grant Agreement No.101076233,“PREXTREME”)funding from the European Union’s Just Transition Fund(JTF)within the project Röntgenlaser-Optimierung der Laserfusion(ROLF),Contract No.5086999001,co-financed by the Saxon State Government out of the State Budget approved by the Saxon State Parliament.
文摘Ab initio modeling of dynamic structure factors(DSF)and related density response properties in the warm dense matter(WDM)regime is a challenging computational task.The DSF,convolved with a probing X-ray beam and instrument function,is measured in X-ray Thom-son scattering(XRTS)experiments,which allow the study of electronic structure properties at the microscopic level.Among the various ab initio methods,linear-response time-dependent density-functional theory(LR-TDDFT)is a key framework for simulating the DSF.The standard approach in LR-TDDFT for computing the DSF relies on the orbital representation.A significant drawback of this method is the unfavorable scaling of the number of required empty bands as the wavenumber increases,making LR-TDDFT impractical for modeling XRTS measurements over large energy scales,such as in backward scattering geometry.In this work,we consider and test an alternative approach to LR-TDDFT that employs the Liouville–Lanczos(LL)method for simulating the DSF of WDM.This approach does not require empty states and allows the DSF at large momentum transfer values and over a broad frequency range to be accessed.We compare the results obtained from the LL method with those from the solution of Dyson’s equation using the standard LR-TDDFT within the projector augmented-wave formalism for isochorically heated aluminum and warm dense hydrogen.Additionally,we utilize exact path integral Monte Carlo results for the imaginary-time density-density correlation function(ITCF)of warm dense hydrogen to rigorously benchmark the LL approach.We discuss the application of the LL method for calculating DSFs and ITCFs at different wavenumbers,the effects of pseudopotentials,and the role of Lorentzian smearing.The successful validation of the LL method under WDM conditions makes it a valuable addition to the ab initio simulation landscape,supporting experimental efforts and advancing WDM theory.
基金supported by the Technology Devel-opment Program(No.S3218794)funded by the Ministry of SMEs and Startups(MSS,Korea)supported by the Nano&Material Technology Development Program through the National Research Foundation of Korea(NRF)funded by the Min-istry of Science and ICT(No.RS-2024-00446825).
文摘Strategic design and synergistic interactions between the electrodes and electroactive materials profoundly influence the energy storage efficiency of supercapacitor devices. Herein, we present the interfacial engineering of CoMoS_(4)-NiS_(2) with a well-defined construction of amorphous/crystalline hetero-phases deposited on carbon cloth using a hydrothermal technique. The optimal in-situ growth of CoMoS_(4)-NiS_(2)@CFC boasts an impressive areal capacity of 1341 mC cm^(-2) and retains ∼91 % capacity after 5000 cycles, attributed to the synergy effect and improved conductivity of multi-metallic sulfide ions over the CFC substrate. Density functional theory (DFT) reveals the metallic nature of CoMoS_(4)-NiS_(2)@CFC and favorable OH- ion adsorption energy of -4.35 eV, enhancing its charge storage capabilities. Furthermore, a hybrid supercapacitor (HSC) and Pouch HSC are assembled utilizing the CoMoS_(4)-NiS_(2)@CFC as a positrode and marine waste jellyfish-derived AC as a negatrode with an aqueous electrolyte. The HSC and PHSC demonstrate superior specific energies of 51.99 and 58.4 W h kg^(-1), respectively, along with corresponding specific powers of 800 and 780 W kg^(-1), maintaining robust stability of ∼90 % stability over 10000 cycles. Additionally, the HSC and PHSC have successfully illuminated several light-emitting diodes (LEDs) demonstrating superior energy storage performance. This work advances the design of hetero-phase multi-metal sulfides, paving the way for high-performance supercapacitor devices.
基金supported by the National Natural Science Foundation of China(No.51701239)the University-Industry Collaborative Education Program of MOEinChina(No.BINTECH-KJZX-20220831-35)the Basic-Scientific-Research-Business-Fee Supporting Project of Henan Province,China(Nos.2023KY35,2023KY40).
文摘Localized corrosion of 304 stainless steel being the significant parts of Starship rocket seriously threatens the long-term service of such aerospace equipment.Scanning electron microscopy,in situ instruments combining electrochemical workstation and Raman spectroscopy,and Density Dunctional Theory(DFT)calculations were employed.The surface morphologies,alloying elements,molecular fingerprint Raman evidence and theoretical mechanism for the localized corrosion of 304 stainless steel during the electrochemical polarization in the mixture solutions containing 0.5 mol/L H_(2)SO_(4) and 2,2'-bipyridine(bipy)with concentrations of 0.001,0.010,0.100 mol/L were discussed.In comparison,the presence of bipy up to 0.100 mol/L in such mixture solutions displayed the neglectable effect on the Fe(Ⅱ)/Fe(Ⅲ)reaction in the polarization process.Raman vibrational frequency around 1492 cm^(-1)was the evidence of pink color appearance due to the formation of[Fe^(Ⅱ)(bipy)_(3)]^(2+).Raman and DFT indicated the yellow color emergence due to the presence ofμ-O-[Fe^(Ⅲ)(bipy)_(2)(H_(2)O)]_(2)^(4+)due to the oxidation reaction of[Fe^(Ⅱ)(bipy)_(3)]^(2+)with H_(2)O_(2) oxidant,and the dimerization of[Fe^(Ⅲ)(bipy)_(3)]^(3+),Furthermore,a quantitative model between[Fe^(Ⅱ)(bipy)_(3)]^(2+)concentration and Raman intensity at 1492 cm^(-1) has been built up.Two linear functions were revealed when[Fe^(Ⅱ)(bipy)_(3)]^(2+)concentrations were at 0-0.002 mol/L and 0.002-0.004 mol/L and a concentration error of less than 5%was evidenced in comparison with that investigated by the inductively coupled plasma.The proposed passivation mechanism and quantitative concentration model of 304 stainless steel have certain significance for its corrosion protection andcorrosionevaluation.
基金supported by the National Natural Science Foundation of China(Nos.12265012 and 12305125)Guizhou Provincial Science and Technology Projects(No.ZK[2022]203)+2 种基金PhD fund of Guizhou Minzu University(No.GZMUZK[2024]QD76)the National Key Laboratory of Neutron Science and Technology(No.NST202401016)the Sichuan Science and Technology Program(No.2024NSFSC1356).
文摘Nuclear masses play a crucial role in both nuclear physics and astrophysics,driving sustained efforts toward precise experi-mental determination and reliable theoretical predictions.In this study,we compiled the newly measured masses for 296 nuclides from 40 references published between 2021 and 2024,subsequent to the release of the latest atomic mass evalu-ation.These data were used to benchmark the performance of several relativistic and nonrelativistic density functionals,including PC-PK1,TMA,SLy4,SV-min,UNEDF1,and the recently proposed PC-L3R.The results for PC-PK1 and PC-L3R were obtained using the state-of-the-art deformed relativistic Hartree-Bogoliubov theory in continuum(DRHBc),whereas the others were adopted from the existing literature.It was found that the DRHBc calculations with PC-PK1 and PC-L3R achieved an accuracy better than 1.5 MeV,outperforming the other functionals,which all exhibited root-mean-square devia-tions exceeding 2 MeV.The odd-even effects and isospin dependence in these theoretical descriptions were examined.The PC-PK1 and PC-L3R descriptions were qualitatively similar,exhibiting robust isospin dependence along the isotopic chains.Finally,a quantitative comparison between the PC-PK1 and PC-L3R results is presented,with the largest discrepancies analyzed in terms of the potential energy curves from the constrained DRHBc calculations.
