The basis functions of the translation invariant shell model are used to construct the ground state nuclear wave functions of <sup>3</sup>H. The used residual two-body interactions consist of central, tens...The basis functions of the translation invariant shell model are used to construct the ground state nuclear wave functions of <sup>3</sup>H. The used residual two-body interactions consist of central, tensor, spin orbit and quadratic spin orbit terms with Gaussian radial dependence. The parameters of these interactions are so chosen in such a way that they represent the long-range attraction and the short-range repulsion of the nucleon-nucleon interactions. These parameters are so chosen to reproduce good agreement between the calculated values of the binding energy, the root mean-square radius, the D-state probability, the magnetic dipole moment and the electric quadrupole moment of the deuteron nucleus. The variation method is then used to calculate the binding energy of triton by varying the oscillator parameter which exists in the nuclear wave function. The obtained nuclear wave functions are then used to calculate the root mean-square radius and the magnetic dipole moment of the triton.展开更多
The random forest algorithm was applied to study the nuclear binding energy and charge radius.The regularized root-mean-square of error(RMSE)was proposed to avoid overfitting during the training of random forest.RMSE ...The random forest algorithm was applied to study the nuclear binding energy and charge radius.The regularized root-mean-square of error(RMSE)was proposed to avoid overfitting during the training of random forest.RMSE for nuclides with Z,N>7 is reduced to 0.816 MeV and 0.0200 fm compared with the six-term liquid drop model and a three-term nuclear charge radius formula,respectively.Specific interest is in the possible(sub)shells among the superheavy region,which is important for searching for new elements and the island of stability.The significance of shell features estimated by the so-called shapely additive explanation method suggests(Z,N)=(92,142)and(98,156)as possible subshells indicated by the binding energy.Because the present observed data is far from the N=184 shell,which is suggested by mean-field investigations,its shell effect is not predicted based on present training.The significance analysis of the nuclear charge radius suggests Z=92 and N=136 as possible subshells.The effect is verified by the shell-corrected nuclear charge radius model.展开更多
The adventitious carbon located at 284.8 eV was used to calibrate samples without the carbon themselves.When the carbon is as a major part of the inorganic material,the adventitious carbon should be identified and use...The adventitious carbon located at 284.8 eV was used to calibrate samples without the carbon themselves.When the carbon is as a major part of the inorganic material,the adventitious carbon should be identified and used as the reference.There is no adventitious carbon on the surfaces of the polymer materials,so using C1s of the carbon in the polymer itself to calibrate the charging effect is reasonable.Furthermore,compared with gold and argon,a more practical and convenient method based on C1s is proposed to get the right positions for binding energy peaks.展开更多
The binding energy of a hydrogenic impurity in self-assembled double quantum dots is calculated via the finitedifference method. The variation in binding energy with donor position, structure parameters and external m...The binding energy of a hydrogenic impurity in self-assembled double quantum dots is calculated via the finitedifference method. The variation in binding energy with donor position, structure parameters and external magnetic field is studied in detail. The results found are: (i) the binding energy has a complex behaviour due to coupling between the two dots; (ii) the binding energy is much larger when the donor is placed in the centre of one dot than in other positions; and (iii) the external magnetic field has different effects on the binding energy for different quantum-dot sizes or lateral confinements.展开更多
In this article, we study the generalized Riemann problem for a scalar non- convex Chapman-Jouguet combustion model in a neighborhood of the origin (t 〉 0) on the (x, t) plane. We focus our attention to the pertu...In this article, we study the generalized Riemann problem for a scalar non- convex Chapman-Jouguet combustion model in a neighborhood of the origin (t 〉 0) on the (x, t) plane. We focus our attention to the perturbation on initial binding energy. The solutions are obtained constructively under the entropy conditions. It can be found that the solutions are essentially different from the corresponding Riemann solutions for some cases. Especially, two important phenomena are observed: the transition from detonation to deflagration followed by a shock, which appears in the numerical simulations [7, 27]; the transition from deflagration to detonation (DDT), which is one of the core problems in gas dynamic combustion.展开更多
The effect of the dielectric mismatch between the well and the barrier materials on the binding energies of shallow donor has been investigated in Inx Ga1-xAs/GaAsstrained quantum well. The binding energies as a funct...The effect of the dielectric mismatch between the well and the barrier materials on the binding energies of shallow donor has been investigated in Inx Ga1-xAs/GaAsstrained quantum well. The binding energies as a function of the well widths and impurity positions in the well and the barriers are obtained by using a variational method. Calculation results show that the effect of the dielectric mismatch is quite sizable and such effect is larger for off-center impurity positions,but the effect of the lattice mismatch is small in general.展开更多
This paper studies the size dependence of biexciton binding energy in single quantum dots (QDs) by using atomic force microscopy and micro-photoluminescence measurements. It finds that the biexciton binding energies...This paper studies the size dependence of biexciton binding energy in single quantum dots (QDs) by using atomic force microscopy and micro-photoluminescence measurements. It finds that the biexciton binding energies in the QDs show "binding" and "antibinding" properties which correspond to the large and small sizes of QDs, respectively. The experimental results can be well interpreted by the biexciton potential curve, calculated from the exciton molecular model and the Heitler London method.展开更多
Owing to the large exciton binding energy(>100 meV)of most organic materials,the process of exciton dissociation into free electrons and holes is seriously hindered,which plays a key role in the photocatalytic syst...Owing to the large exciton binding energy(>100 meV)of most organic materials,the process of exciton dissociation into free electrons and holes is seriously hindered,which plays a key role in the photocatalytic system.In this study,a series of chalcogen(S,Se)-substituted mesoporous covalent organic frameworks(COFs)have been synthesized for enhanced photocatalytic organic transformations.Photoelectrochemical measurements indicate that the introduction of semi-metallic Se atom and the enlargement of conjugation degree can not only reduce the exciton binding energy accelerating the charge separation,but also reduce the band gap of COFs.As a result,the COF-NUST-36 with the lowest exciton binding energy(39.5 meV)shows the highest photocatalytic performance for selective oxidation of amines(up to 98%Conv.and 97.5%Sel.).This work provides a feasible method for designing COFs with high photocatalytic activity by adjusting exciton binding energy.展开更多
The kinetics of hydrogen oxidation reaction(HOR)declines with orders of magnitude when the electrolyte varies from acid to base.Therefore,unveiling the mechanism of pH-dependent HOR and narrowing the acid-base kinetic...The kinetics of hydrogen oxidation reaction(HOR)declines with orders of magnitude when the electrolyte varies from acid to base.Therefore,unveiling the mechanism of pH-dependent HOR and narrowing the acid-base kinetic gap are indispensable and challenging.Here,the HOR behaviors of palladium phosphides and their counterpart(PdP_2/C,Pd_5P_2/C,Pd_3P/C,and Pd/C)in the whole pH region(from pH 1 to 13)are explored.Unexpectedly,there are non-monotonous relationships between their HOR kinetics and varied pHs,showing distinct inflection-point behaviors(inflection points and acid-base kinetic gaps).We find the inflection-point behaviors can be explained by the discrepant role of pH-dependent hydroxyl binding energy(OHBE)and hydrogen binding energy(HBE)induced HOR kinetics under the entire pH range.We further reveal that the strengthened OHBE is responsible for the earlier appearance of the inflection point and much narrower acid-base kinetic gap.These findings are conducive to understanding the mechanism of the pH-targeted HOR process,and provide a new strategy for rational designing advanced HOR electrocatalysts under alkaline electrolyte.展开更多
The role and implication of binding energy through the accretion-induced collapse(AIC)of accreting white dwarfs(WDs)for the production of millisecond pulsars(MSPs)are investigated.The binding energy model is examined ...The role and implication of binding energy through the accretion-induced collapse(AIC)of accreting white dwarfs(WDs)for the production of millisecond pulsars(MSPs)are investigated.The binding energy model is examined due to the dynamic process in closed binary systems,and the possible mass of the companion sufficient to induce their orbital parameters is investigated.The deterministic nature of this interaction has a strong sensitivity to the equation of state of the binary systems(where the compactness of a neutron star is proportional to the amount of binding energy)associated with their initial conditions.This behavior mimics the commonly assumed mass and amount of accreted matter under the instantaneous mass loss(ΔM~0.18M_(⊙)).As a result,this indicates an increase in the MSP’s gravitational mass due to angular momentum losses.The outcome of such a system is then a circular binary MSP in which the companion is a low-mass WD,thus distinguishing the binary formation scenarios.In addition,the results of this work could provide constraints on the expected mass and binding energy of a neutron star based on the accretion rate.展开更多
Reliable calculations of nuclear binding energies are crucial for advancing the research of nuclear physics. Machine learning provides an innovative approach to exploring complex physical problems. In this study, the ...Reliable calculations of nuclear binding energies are crucial for advancing the research of nuclear physics. Machine learning provides an innovative approach to exploring complex physical problems. In this study, the nuclear binding energies are modeled directly using a machine-learning method called the Gaussian process. First, the binding energies for 2238 nuclei with Z > 20 and N > 20 are calculated using the Gaussian process in a physically motivated feature space, yielding an average deviation of 0.046 MeV and a standard deviation of 0.066 MeV. The results show the good learning ability of the Gaussian process in the studies of binding energies. Then, the predictive power of the Gaussian process is studied by calculating the binding energies for 108 nuclei newly included in AME2020. The theoretical results are in good agreement with the experimental data, reflecting the good predictive power of the Gaussian process. Moreover, the α-decay energies for 1169 nuclei with 50 ≤ Z ≤ 110 are derived from the theoretical binding energies calculated using the Gaussian process. The average deviation and the standard deviation are, respectively, 0.047 MeV and 0.070 MeV. Noticeably, the calculated α-decay energies for the two new isotopes ^ (204 )Ac(Huang et al. Phys Lett B 834, 137484(2022)) and ^ (207) Th(Yang et al. Phys Rev C 105, L051302(2022)) agree well with the latest experimental data. These results demonstrate that the Gaussian process is reliable for the calculations of nuclear binding energies. Finally, the α-decay properties of some unknown actinide nuclei are predicted using the Gaussian process. The predicted results can be useful guides for future research on binding energies and α-decay properties.展开更多
Molecular dynamics (MD) method was used to simulate 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) coated with fluorine containing polymers. The mechanical properties and binding energies of PBXs were obtained. It wa...Molecular dynamics (MD) method was used to simulate 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) coated with fluorine containing polymers. The mechanical properties and binding energies of PBXs were obtained. It was found that when the number of chain monomers of fluorine containing polymers was the same, the elasticity of TATB/F2314 was increased more greatly than others and the binding energy of TATB/F2311 was the largest among four PBXs. Detonation heat and velocity of such four PBXs were calculated according to theoretical and empirical formulas. The results show that the order of detonation heat is TATB〉TATB/PVDF〉TATB/F2311〉TATB/ F2314 〉 TATB/PCTFE while the order of detonation velocity is TATB/PVDF 〈 TATB/F2311 〈 TATB/F2314 〈 TATB/PCTFE 〈TATB.展开更多
Although bioinspired sacrificial bonds have been demonstrated to be efficient in improving the mechanical properties of polymer materials, the effect of binding energy of a specific dynamic bond on the ultimate mechan...Although bioinspired sacrificial bonds have been demonstrated to be efficient in improving the mechanical properties of polymer materials, the effect of binding energy of a specific dynamic bond on the ultimate mechanical performance of a polymer network with dual-crosslink remains unclear. In this contribution, diamine and sulfur curing package are introduced simultaneously into a sulfonated cis-1,4-polyisoprene to create dually-crosslinked cis-1,4-polyisoprene network with sulfonate-aminium ionic bonds as the sacrificial bonds. Three diamines (primary, secondary and tertiary) with the same spacer between the two nitrogen atoms are used to create the ionic bonds with different binding energies. Although the binding energy of ionic bond does not affect the glass transition temperature of cis-1,4-polyisoprene (IR), it exerts definite influences on strain-induced crystallization and mechanical performance. The capabilities of diamine in dissipating energy, promoting strain-induced crystallization and enhancing the mechanical performance are in the same order of secondary diamine 〉 primary diamine 〉 tertiary diamine. The variations in mechanical performances are correlated to the binding energy of the ionic bond, which is determined by pKa values.展开更多
Unveiling the role of adsorbed hydroxide involved in the hydrogen oxidation reaction(HOR)under alkaline electrolyte is crucial for the development of advanced HOR electrocatalysts for the alkaline polymer electrolyte ...Unveiling the role of adsorbed hydroxide involved in the hydrogen oxidation reaction(HOR)under alkaline electrolyte is crucial for the development of advanced HOR electrocatalysts for the alkaline polymer electrolyte fuel cells(APEFCs).Herein,we report the synthesis of amorphous RuCr nanosheets with different molar ratios and their HOR performances under alkaline media.We find a volcano correlation between the Cr content in RuCr nanosheets and their alkaline HOR performance.Experimental results and density functional theory(DFT)calculation reveals that the optimized Cr content in RuCr nanosheets could lead to the optimum hydroxide binding energy(OHBE),contributes to their remarkable alkaline HOR performance with mass activity of 568.1 A·gPGM^(–1) at 50 mV,13-fold higher than that of Ru catalyst.When RuCr nanosheet is further used as the anodic electrocatalyst,a peak power density of 1.04 W·cm^(–2 )can be achieved in an APEFC.展开更多
Combined with third generation synchrotron radiation light sources, X-ray photoelectron spectroscopy (XPS) with higher energy resolution, brilliance, enhanced surface sensitivity and photoemission cross section in rea...Combined with third generation synchrotron radiation light sources, X-ray photoelectron spectroscopy (XPS) with higher energy resolution, brilliance, enhanced surface sensitivity and photoemission cross section in real time found extensive applications in solid-gas interface chemistry. This paper reports the calculation of the core-level binding energy shifts (CLS) using the first-principles density functional theory. The interplay between the CLS calculations and XPS measurements to uncover the structures, adsorption sites and chemical reactions in complex surface chemical processes are highlight. Its application on clean low index (111) and vicinal transition metal surfaces, molecular adsorption in terms of sites and configuration, and reaction kinetics are domonstrated.展开更多
In this paper the binding energy of the shallow.donor in CdTe/ZnTe strained double quantum well was calculated.The effect of the finite well potential and strain,resulting from the lattice mismatch,on the binding ener...In this paper the binding energy of the shallow.donor in CdTe/ZnTe strained double quantum well was calculated.The effect of the finite well potential and strain,resulting from the lattice mismatch,on the binding energy of the impurity is included in a variational framework.The binding energy is obtained as a function of the well width,barrier width,and impurity position in the barrier by using a variational method.The result of the present calculation shows that the variational law of the binding energy is similar to that of unstrained materials.展开更多
Simultaneous and distinguishable detection of external stimuli such as light and temperature is of great interest for a variety of scientific and industrial applications.Theoretically,an organic semiconductor with low...Simultaneous and distinguishable detection of external stimuli such as light and temperature is of great interest for a variety of scientific and industrial applications.Theoretically,an organic semiconductor with low exciton binding energy,low thermal activation energy and good charge transporting property produces thermally enhanced photo-electric response in organic phototransistors(OPTs),which thus provides an ideal and effective way to realize the simultaneous and distinguishable detection of temperature and light.However,there is no report on such a kind of organic semiconductor until now.Herein,we designed and synthesized a narrow band gap organic small molecule semiconductor 2,5-bis(2-butyloctyl)-3,6-bis(5-(4-(diphenylamino)phenyl)thiophen-2-yl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione(DPP-T-TPA)with low exciton binding energy(about 37 meV)and small activation energy(about 61 meV)for distinct thermal-dependence of charge carrier and exciton.The low exciton binding energy enables the semiconductor to exhibit strong thermal dependence of exciton dissociation,which contributes to the thermally-enhanced photo-electric response.Furthermore,the low thermal activation energy produces the weak thermal dependence of charge transport,which avoids the disturbance of thermally-modulated charge transport on photo-electric response.Benefiting from these two features,phototransistors based on DPP-T-TPA show great potential in simultaneous and distinguishable detection of light and temperature,which represents a novel and efficient way for bifunctional detection.展开更多
In this paper,we study the symmetry energy and the Wigner energy in the binding energy formula for atomic nuclei.We simultaneously extract the I2 symmetry energy and Wigner energy coefficients using the double differe...In this paper,we study the symmetry energy and the Wigner energy in the binding energy formula for atomic nuclei.We simultaneously extract the I2 symmetry energy and Wigner energy coefficients using the double difference of "experimental" symmetry-Wigner energies,based on the binding energy data of nuclei with A≥16.Our study of the triple difference formula and the "experimental" symmetry-Wigner energy suggests that the macroscopic isospin dependence of binding energies is explained well by the I2 symmetry energy and the Wigner energy,and further consideration of the I4 term in the binding energy formula does not substantially improve the calculation result.展开更多
The band offsets for a Zn1-xin Mgxin Se/Zn1-xout Mgxout Se quantum well heterostructure are determined using the model solid theory. The heavy hole exciton binding energies are investigated with various Mg alloy conte...The band offsets for a Zn1-xin Mgxin Se/Zn1-xout Mgxout Se quantum well heterostructure are determined using the model solid theory. The heavy hole exciton binding energies are investigated with various Mg alloy contents. The effect of mismatch between the dielectric constants between the well and the barrier is taken into account. The dependence of the excitonic transition energies on the geometrical confinement and the Mg alloy is discussed. Non-linear optical properties are determined using the compact density matrix approach. The linear, third order non-linear optical absorption coefficient values and the refractive index changes of the exciton are calculated for different concentrations of magnesium. The results show that the occurred blue shifts of the resonant peak due to the Mg incorporation give the information about the variation of two energy levels in the quantum well width.展开更多
Coiled-coils are well known protein–protein interaction motifs,with the leucine zipper region of activator protein-1(AP-1)consisting of the c-Jun and c-Fos proteins being a typical example.Molecular dynamics(MD)simul...Coiled-coils are well known protein–protein interaction motifs,with the leucine zipper region of activator protein-1(AP-1)consisting of the c-Jun and c-Fos proteins being a typical example.Molecular dynamics(MD)simulations using the MM/GBSA method have been used to predict the free energy of interaction of these proteins.The influence of force field polarisation and capping on the predicted free energy of binding of complexes with different electrostatic environments(net charge)were investigated.Although both force field polarisation and peptide capping are important for the prediction of the absolute free energy of binding,peptide capping has the largest influence on the predicted free energy of binding.Polarisable simulations appear better suited to determine structural properties of the complexes of these proteins while non-polarisable simulations seem to give better predictions of the associated free energies of binding.展开更多
文摘The basis functions of the translation invariant shell model are used to construct the ground state nuclear wave functions of <sup>3</sup>H. The used residual two-body interactions consist of central, tensor, spin orbit and quadratic spin orbit terms with Gaussian radial dependence. The parameters of these interactions are so chosen in such a way that they represent the long-range attraction and the short-range repulsion of the nucleon-nucleon interactions. These parameters are so chosen to reproduce good agreement between the calculated values of the binding energy, the root mean-square radius, the D-state probability, the magnetic dipole moment and the electric quadrupole moment of the deuteron nucleus. The variation method is then used to calculate the binding energy of triton by varying the oscillator parameter which exists in the nuclear wave function. The obtained nuclear wave functions are then used to calculate the root mean-square radius and the magnetic dipole moment of the triton.
基金Supported by Basic and Applied Basic Research Project of Guangdong Province(2021B0301030006)。
文摘The random forest algorithm was applied to study the nuclear binding energy and charge radius.The regularized root-mean-square of error(RMSE)was proposed to avoid overfitting during the training of random forest.RMSE for nuclides with Z,N>7 is reduced to 0.816 MeV and 0.0200 fm compared with the six-term liquid drop model and a three-term nuclear charge radius formula,respectively.Specific interest is in the possible(sub)shells among the superheavy region,which is important for searching for new elements and the island of stability.The significance of shell features estimated by the so-called shapely additive explanation method suggests(Z,N)=(92,142)and(98,156)as possible subshells indicated by the binding energy.Because the present observed data is far from the N=184 shell,which is suggested by mean-field investigations,its shell effect is not predicted based on present training.The significance analysis of the nuclear charge radius suggests Z=92 and N=136 as possible subshells.The effect is verified by the shell-corrected nuclear charge radius model.
基金Funded by the National Key R&D Program of China(2017YFC0210802)the Fundamental Research Funds for the Central Universities(WUT 2019III015GX)。
文摘The adventitious carbon located at 284.8 eV was used to calibrate samples without the carbon themselves.When the carbon is as a major part of the inorganic material,the adventitious carbon should be identified and used as the reference.There is no adventitious carbon on the surfaces of the polymer materials,so using C1s of the carbon in the polymer itself to calibrate the charging effect is reasonable.Furthermore,compared with gold and argon,a more practical and convenient method based on C1s is proposed to get the right positions for binding energy peaks.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10674040)the Natural Science Foundation of Hebei Province of China (Grant No. A2011205092)the Scientific and Technological Research and Development Projects of Handan City (Grant No. 1128120063-3)
文摘The binding energy of a hydrogenic impurity in self-assembled double quantum dots is calculated via the finitedifference method. The variation in binding energy with donor position, structure parameters and external magnetic field is studied in detail. The results found are: (i) the binding energy has a complex behaviour due to coupling between the two dots; (ii) the binding energy is much larger when the donor is placed in the centre of one dot than in other positions; and (iii) the external magnetic field has different effects on the binding energy for different quantum-dot sizes or lateral confinements.
基金Supported by NUAA Research Funding (NS2011001)NUAA’S Scientific Fund forthe Introduction of Qualified Personal,NSFC grant 10971130+1 种基金Shanghai Leading Academic Discipline ProjectJ 50101Shanghai Municipal Education Commission of Scientific Research Innovation Project 112284
文摘In this article, we study the generalized Riemann problem for a scalar non- convex Chapman-Jouguet combustion model in a neighborhood of the origin (t 〉 0) on the (x, t) plane. We focus our attention to the perturbation on initial binding energy. The solutions are obtained constructively under the entropy conditions. It can be found that the solutions are essentially different from the corresponding Riemann solutions for some cases. Especially, two important phenomena are observed: the transition from detonation to deflagration followed by a shock, which appears in the numerical simulations [7, 27]; the transition from deflagration to detonation (DDT), which is one of the core problems in gas dynamic combustion.
文摘The effect of the dielectric mismatch between the well and the barrier materials on the binding energies of shallow donor has been investigated in Inx Ga1-xAs/GaAsstrained quantum well. The binding energies as a function of the well widths and impurity positions in the well and the barriers are obtained by using a variational method. Calculation results show that the effect of the dielectric mismatch is quite sizable and such effect is larger for off-center impurity positions,but the effect of the lattice mismatch is small in general.
基金Project supported by the National Natural Science Foundations of China (Grant Nos O69C041001 and 2007CB924904)
文摘This paper studies the size dependence of biexciton binding energy in single quantum dots (QDs) by using atomic force microscopy and micro-photoluminescence measurements. It finds that the biexciton binding energies in the QDs show "binding" and "antibinding" properties which correspond to the large and small sizes of QDs, respectively. The experimental results can be well interpreted by the biexciton potential curve, calculated from the exciton molecular model and the Heitler London method.
基金financially supported by the National Natural Science Foundation of China(No.22171136)the Natural Science Foundation of Jiangsu Province(Nos.BK20220928,BK20220079)+4 种基金the Fundamental Research Funds for the Central Universities(Nos.30921011102,30922010902)the Medical Innovation and Development Project of Lanzhou University(No.lzuyxcx-2022-156)CAMS Innovation Fund for Medical Sciences(CIFMS,Nos.2019-I2M-5-074,2021-I2M-1-026,2021-I2M-3-001)the Startup Funding from Nanjing University of Science and Technology(Nos.AE89990,AE89991/376)G.Zhang acknowledges the support of the Thousand Young Talent Plan.
文摘Owing to the large exciton binding energy(>100 meV)of most organic materials,the process of exciton dissociation into free electrons and holes is seriously hindered,which plays a key role in the photocatalytic system.In this study,a series of chalcogen(S,Se)-substituted mesoporous covalent organic frameworks(COFs)have been synthesized for enhanced photocatalytic organic transformations.Photoelectrochemical measurements indicate that the introduction of semi-metallic Se atom and the enlargement of conjugation degree can not only reduce the exciton binding energy accelerating the charge separation,but also reduce the band gap of COFs.As a result,the COF-NUST-36 with the lowest exciton binding energy(39.5 meV)shows the highest photocatalytic performance for selective oxidation of amines(up to 98%Conv.and 97.5%Sel.).This work provides a feasible method for designing COFs with high photocatalytic activity by adjusting exciton binding energy.
基金supported by the National Key Research and Development Program of China(2021YFB4001200)the National Natural Science Foundation of China(22272121,21972107)the Natural Science Foundation of Hubei Province(2020CFA095)。
文摘The kinetics of hydrogen oxidation reaction(HOR)declines with orders of magnitude when the electrolyte varies from acid to base.Therefore,unveiling the mechanism of pH-dependent HOR and narrowing the acid-base kinetic gap are indispensable and challenging.Here,the HOR behaviors of palladium phosphides and their counterpart(PdP_2/C,Pd_5P_2/C,Pd_3P/C,and Pd/C)in the whole pH region(from pH 1 to 13)are explored.Unexpectedly,there are non-monotonous relationships between their HOR kinetics and varied pHs,showing distinct inflection-point behaviors(inflection points and acid-base kinetic gaps).We find the inflection-point behaviors can be explained by the discrepant role of pH-dependent hydroxyl binding energy(OHBE)and hydrogen binding energy(HBE)induced HOR kinetics under the entire pH range.We further reveal that the strengthened OHBE is responsible for the earlier appearance of the inflection point and much narrower acid-base kinetic gap.These findings are conducive to understanding the mechanism of the pH-targeted HOR process,and provide a new strategy for rational designing advanced HOR electrocatalysts under alkaline electrolyte.
文摘The role and implication of binding energy through the accretion-induced collapse(AIC)of accreting white dwarfs(WDs)for the production of millisecond pulsars(MSPs)are investigated.The binding energy model is examined due to the dynamic process in closed binary systems,and the possible mass of the companion sufficient to induce their orbital parameters is investigated.The deterministic nature of this interaction has a strong sensitivity to the equation of state of the binary systems(where the compactness of a neutron star is proportional to the amount of binding energy)associated with their initial conditions.This behavior mimics the commonly assumed mass and amount of accreted matter under the instantaneous mass loss(ΔM~0.18M_(⊙)).As a result,this indicates an increase in the MSP’s gravitational mass due to angular momentum losses.The outcome of such a system is then a circular binary MSP in which the companion is a low-mass WD,thus distinguishing the binary formation scenarios.In addition,the results of this work could provide constraints on the expected mass and binding energy of a neutron star based on the accretion rate.
基金the National Key R&D Program of China(No.2023YFA1606503)the National Natural Science Foundation of China(Nos.12035011,11975167,11947211,11905103,11881240623,and 11961141003).
文摘Reliable calculations of nuclear binding energies are crucial for advancing the research of nuclear physics. Machine learning provides an innovative approach to exploring complex physical problems. In this study, the nuclear binding energies are modeled directly using a machine-learning method called the Gaussian process. First, the binding energies for 2238 nuclei with Z > 20 and N > 20 are calculated using the Gaussian process in a physically motivated feature space, yielding an average deviation of 0.046 MeV and a standard deviation of 0.066 MeV. The results show the good learning ability of the Gaussian process in the studies of binding energies. Then, the predictive power of the Gaussian process is studied by calculating the binding energies for 108 nuclei newly included in AME2020. The theoretical results are in good agreement with the experimental data, reflecting the good predictive power of the Gaussian process. Moreover, the α-decay energies for 1169 nuclei with 50 ≤ Z ≤ 110 are derived from the theoretical binding energies calculated using the Gaussian process. The average deviation and the standard deviation are, respectively, 0.047 MeV and 0.070 MeV. Noticeably, the calculated α-decay energies for the two new isotopes ^ (204 )Ac(Huang et al. Phys Lett B 834, 137484(2022)) and ^ (207) Th(Yang et al. Phys Rev C 105, L051302(2022)) agree well with the latest experimental data. These results demonstrate that the Gaussian process is reliable for the calculations of nuclear binding energies. Finally, the α-decay properties of some unknown actinide nuclei are predicted using the Gaussian process. The predicted results can be useful guides for future research on binding energies and α-decay properties.
基金Project supported by the Significant Fundation of China Academy of Engineering Physics (No. 2004Z0503) and the National Natural Science Foundation of China (No. 10176012).
文摘Molecular dynamics (MD) method was used to simulate 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) coated with fluorine containing polymers. The mechanical properties and binding energies of PBXs were obtained. It was found that when the number of chain monomers of fluorine containing polymers was the same, the elasticity of TATB/F2314 was increased more greatly than others and the binding energy of TATB/F2311 was the largest among four PBXs. Detonation heat and velocity of such four PBXs were calculated according to theoretical and empirical formulas. The results show that the order of detonation heat is TATB〉TATB/PVDF〉TATB/F2311〉TATB/ F2314 〉 TATB/PCTFE while the order of detonation velocity is TATB/PVDF 〈 TATB/F2311 〈 TATB/F2314 〈 TATB/PCTFE 〈TATB.
基金financially supported by the National Basic Research Program of China(No.2015CB654700(2015CB654703))the National Natural Science Foundation of China(Nos.51673065,51703064,51473050 and 51333003)Fundamental Research Funds for the Central Universities(No.2017PY006)
文摘Although bioinspired sacrificial bonds have been demonstrated to be efficient in improving the mechanical properties of polymer materials, the effect of binding energy of a specific dynamic bond on the ultimate mechanical performance of a polymer network with dual-crosslink remains unclear. In this contribution, diamine and sulfur curing package are introduced simultaneously into a sulfonated cis-1,4-polyisoprene to create dually-crosslinked cis-1,4-polyisoprene network with sulfonate-aminium ionic bonds as the sacrificial bonds. Three diamines (primary, secondary and tertiary) with the same spacer between the two nitrogen atoms are used to create the ionic bonds with different binding energies. Although the binding energy of ionic bond does not affect the glass transition temperature of cis-1,4-polyisoprene (IR), it exerts definite influences on strain-induced crystallization and mechanical performance. The capabilities of diamine in dissipating energy, promoting strain-induced crystallization and enhancing the mechanical performance are in the same order of secondary diamine 〉 primary diamine 〉 tertiary diamine. The variations in mechanical performances are correlated to the binding energy of the ionic bond, which is determined by pKa values.
基金supported bythe National Key Research and Development program of China(2021YFB4001200,2018YFB1502302)the National Natural Science Foundation of China(21972107)+1 种基金the Fundamental Reseearch Funds for the Central Universities(2042022kf1179)the Natural Science Foundation of Hubei Province(2020CFA095)。
文摘Unveiling the role of adsorbed hydroxide involved in the hydrogen oxidation reaction(HOR)under alkaline electrolyte is crucial for the development of advanced HOR electrocatalysts for the alkaline polymer electrolyte fuel cells(APEFCs).Herein,we report the synthesis of amorphous RuCr nanosheets with different molar ratios and their HOR performances under alkaline media.We find a volcano correlation between the Cr content in RuCr nanosheets and their alkaline HOR performance.Experimental results and density functional theory(DFT)calculation reveals that the optimized Cr content in RuCr nanosheets could lead to the optimum hydroxide binding energy(OHBE),contributes to their remarkable alkaline HOR performance with mass activity of 568.1 A·gPGM^(–1) at 50 mV,13-fold higher than that of Ru catalyst.When RuCr nanosheet is further used as the anodic electrocatalyst,a peak power density of 1.04 W·cm^(–2 )can be achieved in an APEFC.
基金the financial support from the National Natural Sci-ence Foundation of China (Grant Nos. 20733008, 20873142)the National Basic Research Program of China (2007CB815205)
文摘Combined with third generation synchrotron radiation light sources, X-ray photoelectron spectroscopy (XPS) with higher energy resolution, brilliance, enhanced surface sensitivity and photoemission cross section in real time found extensive applications in solid-gas interface chemistry. This paper reports the calculation of the core-level binding energy shifts (CLS) using the first-principles density functional theory. The interplay between the CLS calculations and XPS measurements to uncover the structures, adsorption sites and chemical reactions in complex surface chemical processes are highlight. Its application on clean low index (111) and vicinal transition metal surfaces, molecular adsorption in terms of sites and configuration, and reaction kinetics are domonstrated.
文摘In this paper the binding energy of the shallow.donor in CdTe/ZnTe strained double quantum well was calculated.The effect of the finite well potential and strain,resulting from the lattice mismatch,on the binding energy of the impurity is included in a variational framework.The binding energy is obtained as a function of the well width,barrier width,and impurity position in the barrier by using a variational method.The result of the present calculation shows that the variational law of the binding energy is similar to that of unstrained materials.
基金supported by the National Key Research and Development Program(2018YFA0703200,2016YFB0401100,2016YFA0200803)National Natural Science Foundation of China(52073210,21905199,21573277,51633006)Tianjin Natural Science Foundation(19JCZDJC37400,194214030036,20JCQNJC01520)。
文摘Simultaneous and distinguishable detection of external stimuli such as light and temperature is of great interest for a variety of scientific and industrial applications.Theoretically,an organic semiconductor with low exciton binding energy,low thermal activation energy and good charge transporting property produces thermally enhanced photo-electric response in organic phototransistors(OPTs),which thus provides an ideal and effective way to realize the simultaneous and distinguishable detection of temperature and light.However,there is no report on such a kind of organic semiconductor until now.Herein,we designed and synthesized a narrow band gap organic small molecule semiconductor 2,5-bis(2-butyloctyl)-3,6-bis(5-(4-(diphenylamino)phenyl)thiophen-2-yl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione(DPP-T-TPA)with low exciton binding energy(about 37 meV)and small activation energy(about 61 meV)for distinct thermal-dependence of charge carrier and exciton.The low exciton binding energy enables the semiconductor to exhibit strong thermal dependence of exciton dissociation,which contributes to the thermally-enhanced photo-electric response.Furthermore,the low thermal activation energy produces the weak thermal dependence of charge transport,which avoids the disturbance of thermally-modulated charge transport on photo-electric response.Benefiting from these two features,phototransistors based on DPP-T-TPA show great potential in simultaneous and distinguishable detection of light and temperature,which represents a novel and efficient way for bifunctional detection.
基金Supported by the National Key R&D Program of China(2018YFA0404403)the National Natural Science Foundation of China(12075169,11605122,11875188)。
文摘In this paper,we study the symmetry energy and the Wigner energy in the binding energy formula for atomic nuclei.We simultaneously extract the I2 symmetry energy and Wigner energy coefficients using the double difference of "experimental" symmetry-Wigner energies,based on the binding energy data of nuclei with A≥16.Our study of the triple difference formula and the "experimental" symmetry-Wigner energy suggests that the macroscopic isospin dependence of binding energies is explained well by the I2 symmetry energy and the Wigner energy,and further consideration of the I4 term in the binding energy formula does not substantially improve the calculation result.
文摘The band offsets for a Zn1-xin Mgxin Se/Zn1-xout Mgxout Se quantum well heterostructure are determined using the model solid theory. The heavy hole exciton binding energies are investigated with various Mg alloy contents. The effect of mismatch between the dielectric constants between the well and the barrier is taken into account. The dependence of the excitonic transition energies on the geometrical confinement and the Mg alloy is discussed. Non-linear optical properties are determined using the compact density matrix approach. The linear, third order non-linear optical absorption coefficient values and the refractive index changes of the exciton are calculated for different concentrations of magnesium. The results show that the occurred blue shifts of the resonant peak due to the Mg incorporation give the information about the variation of two energy levels in the quantum well width.
基金the State Key Laboratory of Phytochemistry and Plant Resources in West China,Kunming Institute of Botany,Chinese Academy of Sciences(P2013-ZZ05).
文摘Coiled-coils are well known protein–protein interaction motifs,with the leucine zipper region of activator protein-1(AP-1)consisting of the c-Jun and c-Fos proteins being a typical example.Molecular dynamics(MD)simulations using the MM/GBSA method have been used to predict the free energy of interaction of these proteins.The influence of force field polarisation and capping on the predicted free energy of binding of complexes with different electrostatic environments(net charge)were investigated.Although both force field polarisation and peptide capping are important for the prediction of the absolute free energy of binding,peptide capping has the largest influence on the predicted free energy of binding.Polarisable simulations appear better suited to determine structural properties of the complexes of these proteins while non-polarisable simulations seem to give better predictions of the associated free energies of binding.