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
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 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 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
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
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
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
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
The binding energy of the deuteron is estimated from the scalar strong interaction hadron theory SSI. The predicted value is 7.7% lower than the measured value. Existence of a spin 1 dineutron with a binding energy 4/...The binding energy of the deuteron is estimated from the scalar strong interaction hadron theory SSI. The predicted value is 7.7% lower than the measured value. Existence of a spin 1 dineutron with a binding energy 4/5 that of the deuteron or 1.78 MeV is predicted. This is verified by the dineutron, first observed in 2012, in <sup>16</sup>Be decay. No free dineutrons are expected to exist in nature as they can decay into deuterons. These binding energies are limited by short range strong interaction internucleon forces but consist of long range electrostatic energies from quark charges.展开更多
The tensor parts of Skyrme interactions are constrained from the collective charge-exchange spin-dipole and Gamow-Teller excitation energies in 90Zr and 208Pb,together with the isotopic dependence of energy splitting ...The tensor parts of Skyrme interactions are constrained from the collective charge-exchange spin-dipole and Gamow-Teller excitation energies in 90Zr and 208Pb,together with the isotopic dependence of energy splitting between proton h11=2 and g7=2 single-particle orbits along the Z=50 isotopes.With the optimized tensor interactions,the binding energies of spherical or weakly deformed nuclei with A=54-228 are studied systematically.The present results show that the global effect of tensor interaction is attractive and systematically increases the binding energies of all these nuclei and makes the nuclei more bound.The root mean squared deviation of the calculated binding energies from the experimental values is significantly improved by the optimized tensor interactions,and the contribution of the tensor interaction to the binding energy is estimated.展开更多
This article proposes the potential energy function of nucleon in nucleus, derives the expression equation of nuclear force, shows that nucleus has the shell structure by the solving the Schr?dinger equation of nucleo...This article proposes the potential energy function of nucleon in nucleus, derives the expression equation of nuclear force, shows that nucleus has the shell structure by the solving the Schr?dinger equation of nucleon, obtains the magic numbers, and interprets the past experimental results in theory;for example the radius of nucleus is proportional to the cubic root of nucleon number, the nuclear force is repulsive in the depths of nucleus and attractive in the surface layer, and the variation of average binding energy of nucleons with the nucleon number.展开更多
Carbon nitride thin films deposited using dc unbalanced magnetron sputtering system have been analyzed by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT1R) and Raman spectroscopy. ...Carbon nitride thin films deposited using dc unbalanced magnetron sputtering system have been analyzed by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT1R) and Raman spectroscopy. The XPS data show that N1s binding states depend on substrate temperature Ts, in which the peak at 400.0 eV increases with Ts, whereas the peak at 398.3 eV decreases with Ts slightly On the basis of XPS, FT1R and Raman spectra, the assignment of N1s electron binding energies was made. The peak at 400.0 eV is attributed to N atoms bonded to sp2 coordinated C atoms. The peak at 398.3 eV is attributed to N atoms bonded to sp3 coordinated C atoms as well as N C bonds.展开更多
Breast cancer is a common malignancy in female,which seriously endangers women’s health.Chinese medicine believed that the incidence of breast cancer is related to“Stagnation of Liver-Qi”and“Phlegm,Disharmony of T...Breast cancer is a common malignancy in female,which seriously endangers women’s health.Chinese medicine believed that the incidence of breast cancer is related to“Stagnation of Liver-Qi”and“Phlegm,Disharmony of Thoroughfare and Conception Vessels”,“Stagnation of Qi and Blood Stasis”,constitution and other characteristics.Modern research believed that phlegm is related to abnormal energy metabolism of tumor cells,and stasis is the pathological change of tumor angiogenesis.How to combine tumor angiogenesis and energy replacement abnormality with the theory of“Binding of Phlegm and Stasis”has become a new direction of traditional Chinese medicine anti-tumor research.The drugs of“Activating Blood Circulation”and“Removing Blood Stasis”,“Resolving Phlegm”and“Dispersing Constipation”have a wide range of pharmacological effects and definite curative effect.They have the functions of anti-inflammatory,anti-tumor,anti-pathogenic microorganism and improving the immune ability of the body.In this paper,the effects and mechanisms of phlegm-reducing and stasis dispersing active ingredients and compound preparations in regulating angiogenesis and energy metabolism of breast cancer were reviewed,and the differences in efficacy,targets and pathways of Phlegm-Reducing and Stasis Dispersing drugs were summarized,so as to provide some reference for the research and development of traditional Chinese medicine for breast cancer.展开更多
According to the new proton and neutron nuclear picture described earlier, the structure of the nucleus will also be given a new interpretation. The role of the delocalized electrons detached from the outer shell of n...According to the new proton and neutron nuclear picture described earlier, the structure of the nucleus will also be given a new interpretation. The role of the delocalized electrons detached from the outer shell of neutrons is shown in the binding energy value of the nucleus. It is pointed out that the spatial arrangement of nucleons is also very important for the stability of nuclei according to the analyzation of the magic numbers from a geometric point of view.展开更多
A new term was added to the well-known semi-empirical mass formula to account for the changes due to gravitational attraction between nucleons in the liquid drop, as well as, accommodates for the necessary corrections...A new term was added to the well-known semi-empirical mass formula to account for the changes due to gravitational attraction between nucleons in the liquid drop, as well as, accommodates for the necessary corrections in the binding energy of a nucleus. The results of our calculations show a straight forward evidence that the gravitational attraction bears a reasonable contribution to the binding energy. On the other hand, employing the gravitational term in the semi empirical mass formula was led to the calculation of gravitational constant at subnuclear level.展开更多
Industrial growth in recent years led to air pollution and an increase in concentration of hazardous gases such as O<sub>3</sub> and NO. Developing new materials is important to detect and reduce air pollu...Industrial growth in recent years led to air pollution and an increase in concentration of hazardous gases such as O<sub>3</sub> and NO. Developing new materials is important to detect and reduce air pollutants. While catalytic decomposition and zeolites are traditional ways used to reduce the amount of these gases. We need to develop and explore new promising materials. Covalent organic framework (COF) has become an attractive platform for researcher due to its extended robust covalent bonds, porosity, and crystallinity. In this study, first principal calculations were performed for gases adsorption using COFs containing nitrogen and π-bonds. Different building blocks (BBs) and linkers (LINKs/LINK1 & LINK2) were investigated by means of density functional theory (DFT) calculations with B3LYP and 3-21G basis sets to calculate the binding energies of gases @COF systems. Electrostatic potential maps (ESPM), Mulliken charges and non-covalent interaction (NCI) are used to understand the type of interactions between gas and COFs fragments. O3 was found to bind strongly with COF system in comparison with NO which could make COF a useful selective material for mixed gases environment for sensing and removal application.展开更多
The global nuclear mass based on the macroscopic-microscopic model was studied by applying a newly designed multi-task learning artificial neural network(MTL-ANN). First, the reported nuclear binding energies of 2095 ...The global nuclear mass based on the macroscopic-microscopic model was studied by applying a newly designed multi-task learning artificial neural network(MTL-ANN). First, the reported nuclear binding energies of 2095 nuclei(Z ≥ 8, N ≥ 8) released in the latest Atomic Mass Evaluation AME2020 and the deviations between the fitting result of the liquid drop model(LDM)and data from AME2020 for each nucleus were obtained.To compensate for the deviations and investigate the possible ignored physics in the LDM, the MTL-ANN method was introduced in the model. Compared to the single-task learning(STL) method, this new network has a powerful ability to simultaneously learn multi-nuclear properties,such as the binding energies and single neutron and proton separation energies. Moreover, it is highly effective in reducing the risk of overfitting and achieving better predictions. Consequently, good predictions can be obtained using this nuclear mass model for both the training and validation datasets and for the testing dataset. In detail, the global root mean square(RMS) of the binding energy is effectively reduced from approximately 2.4 MeV of LDM to the current 0.2 MeV, and the RMS of Sn, Spcan also reach approximately 0.2 MeV. Moreover, compared to STL, for the training and validation sets, 3-9% improvement can be achieved with the binding energy, and 20-30% improvement for S_(n), S_(p);for the testing sets, the reduction in deviations can even reach 30-40%, which significantly illustrates the advantage of the current MTL.展开更多
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.
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 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 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.
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.
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.
文摘The binding energy of the deuteron is estimated from the scalar strong interaction hadron theory SSI. The predicted value is 7.7% lower than the measured value. Existence of a spin 1 dineutron with a binding energy 4/5 that of the deuteron or 1.78 MeV is predicted. This is verified by the dineutron, first observed in 2012, in <sup>16</sup>Be decay. No free dineutrons are expected to exist in nature as they can decay into deuterons. These binding energies are limited by short range strong interaction internucleon forces but consist of long range electrostatic energies from quark charges.
基金supported by the National Natural Science Foundation of China(Nos.11575120 and 11822504)JSPS KAKENHI(No.JP19K03858)
文摘The tensor parts of Skyrme interactions are constrained from the collective charge-exchange spin-dipole and Gamow-Teller excitation energies in 90Zr and 208Pb,together with the isotopic dependence of energy splitting between proton h11=2 and g7=2 single-particle orbits along the Z=50 isotopes.With the optimized tensor interactions,the binding energies of spherical or weakly deformed nuclei with A=54-228 are studied systematically.The present results show that the global effect of tensor interaction is attractive and systematically increases the binding energies of all these nuclei and makes the nuclei more bound.The root mean squared deviation of the calculated binding energies from the experimental values is significantly improved by the optimized tensor interactions,and the contribution of the tensor interaction to the binding energy is estimated.
文摘This article proposes the potential energy function of nucleon in nucleus, derives the expression equation of nuclear force, shows that nucleus has the shell structure by the solving the Schr?dinger equation of nucleon, obtains the magic numbers, and interprets the past experimental results in theory;for example the radius of nucleus is proportional to the cubic root of nucleon number, the nuclear force is repulsive in the depths of nucleus and attractive in the surface layer, and the variation of average binding energy of nucleons with the nucleon number.
文摘Carbon nitride thin films deposited using dc unbalanced magnetron sputtering system have been analyzed by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT1R) and Raman spectroscopy. The XPS data show that N1s binding states depend on substrate temperature Ts, in which the peak at 400.0 eV increases with Ts, whereas the peak at 398.3 eV decreases with Ts slightly On the basis of XPS, FT1R and Raman spectra, the assignment of N1s electron binding energies was made. The peak at 400.0 eV is attributed to N atoms bonded to sp2 coordinated C atoms. The peak at 398.3 eV is attributed to N atoms bonded to sp3 coordinated C atoms as well as N C bonds.
文摘Breast cancer is a common malignancy in female,which seriously endangers women’s health.Chinese medicine believed that the incidence of breast cancer is related to“Stagnation of Liver-Qi”and“Phlegm,Disharmony of Thoroughfare and Conception Vessels”,“Stagnation of Qi and Blood Stasis”,constitution and other characteristics.Modern research believed that phlegm is related to abnormal energy metabolism of tumor cells,and stasis is the pathological change of tumor angiogenesis.How to combine tumor angiogenesis and energy replacement abnormality with the theory of“Binding of Phlegm and Stasis”has become a new direction of traditional Chinese medicine anti-tumor research.The drugs of“Activating Blood Circulation”and“Removing Blood Stasis”,“Resolving Phlegm”and“Dispersing Constipation”have a wide range of pharmacological effects and definite curative effect.They have the functions of anti-inflammatory,anti-tumor,anti-pathogenic microorganism and improving the immune ability of the body.In this paper,the effects and mechanisms of phlegm-reducing and stasis dispersing active ingredients and compound preparations in regulating angiogenesis and energy metabolism of breast cancer were reviewed,and the differences in efficacy,targets and pathways of Phlegm-Reducing and Stasis Dispersing drugs were summarized,so as to provide some reference for the research and development of traditional Chinese medicine for breast cancer.
文摘According to the new proton and neutron nuclear picture described earlier, the structure of the nucleus will also be given a new interpretation. The role of the delocalized electrons detached from the outer shell of neutrons is shown in the binding energy value of the nucleus. It is pointed out that the spatial arrangement of nucleons is also very important for the stability of nuclei according to the analyzation of the magic numbers from a geometric point of view.
文摘A new term was added to the well-known semi-empirical mass formula to account for the changes due to gravitational attraction between nucleons in the liquid drop, as well as, accommodates for the necessary corrections in the binding energy of a nucleus. The results of our calculations show a straight forward evidence that the gravitational attraction bears a reasonable contribution to the binding energy. On the other hand, employing the gravitational term in the semi empirical mass formula was led to the calculation of gravitational constant at subnuclear level.
文摘Industrial growth in recent years led to air pollution and an increase in concentration of hazardous gases such as O<sub>3</sub> and NO. Developing new materials is important to detect and reduce air pollutants. While catalytic decomposition and zeolites are traditional ways used to reduce the amount of these gases. We need to develop and explore new promising materials. Covalent organic framework (COF) has become an attractive platform for researcher due to its extended robust covalent bonds, porosity, and crystallinity. In this study, first principal calculations were performed for gases adsorption using COFs containing nitrogen and π-bonds. Different building blocks (BBs) and linkers (LINKs/LINK1 & LINK2) were investigated by means of density functional theory (DFT) calculations with B3LYP and 3-21G basis sets to calculate the binding energies of gases @COF systems. Electrostatic potential maps (ESPM), Mulliken charges and non-covalent interaction (NCI) are used to understand the type of interactions between gas and COFs fragments. O3 was found to bind strongly with COF system in comparison with NO which could make COF a useful selective material for mixed gases environment for sensing and removal application.
基金supported by the National Natural Science Foundation of China(Nos.1187050492,12005303,and 12175170).
文摘The global nuclear mass based on the macroscopic-microscopic model was studied by applying a newly designed multi-task learning artificial neural network(MTL-ANN). First, the reported nuclear binding energies of 2095 nuclei(Z ≥ 8, N ≥ 8) released in the latest Atomic Mass Evaluation AME2020 and the deviations between the fitting result of the liquid drop model(LDM)and data from AME2020 for each nucleus were obtained.To compensate for the deviations and investigate the possible ignored physics in the LDM, the MTL-ANN method was introduced in the model. Compared to the single-task learning(STL) method, this new network has a powerful ability to simultaneously learn multi-nuclear properties,such as the binding energies and single neutron and proton separation energies. Moreover, it is highly effective in reducing the risk of overfitting and achieving better predictions. Consequently, good predictions can be obtained using this nuclear mass model for both the training and validation datasets and for the testing dataset. In detail, the global root mean square(RMS) of the binding energy is effectively reduced from approximately 2.4 MeV of LDM to the current 0.2 MeV, and the RMS of Sn, Spcan also reach approximately 0.2 MeV. Moreover, compared to STL, for the training and validation sets, 3-9% improvement can be achieved with the binding energy, and 20-30% improvement for S_(n), S_(p);for the testing sets, the reduction in deviations can even reach 30-40%, which significantly illustrates the advantage of the current MTL.