The Wilson coefficients of the standard model effective field theory are subject to a series of positivity bounds.It has been shown that while the positivity part of the ultraviolet(UV)partial wave unitarity leads to ...The Wilson coefficients of the standard model effective field theory are subject to a series of positivity bounds.It has been shown that while the positivity part of the ultraviolet(UV)partial wave unitarity leads to the Wilson coefficients living in a convex cone,further including the nonpositivity part caps the cone from above.For Higgs scattering,a capped positivity cone was obtained using a simplified,linear unitarity condition without utilizing the full internal symmetries of Higgs scattering.Here,we further implement stronger nonlinear unitarity conditions from the UV,which generically gives rise to better bounds.We show that,for the Higgs case in particular,while the nonlinear unitarity conditions per se do not enhance the bounds,the fuller use of the internal symmetries do shrink the capped positivity cone significantly.展开更多
A general prediction model for seven heavy metals was established using the heavy metal contents of 207soil samples measured by a portable X-ray fluorescence spectrometer(XRF)and six environmental factors as model cor...A general prediction model for seven heavy metals was established using the heavy metal contents of 207soil samples measured by a portable X-ray fluorescence spectrometer(XRF)and six environmental factors as model correction coefficients.The eXtreme Gradient Boosting(XGBoost)model was used to fit the relationship between the content of heavy metals and environment characteristics to evaluate the soil ecological risk of the smelting site.The results demonstrated that the generalized prediction model developed for Pb,Cd,and As was highly accurate with fitted coefficients(R^(2))values of 0.911,0.950,and 0.835,respectively.Topsoil presented the highest ecological risk,and there existed high potential ecological risk at some positions with different depths due to high mobility of Cd.Generally,the application of machine learning significantly increased the accuracy of pXRF measurements,and identified key environmental factors.The adapted potential ecological risk assessment emphasized the need to focus on Pb,Cd,and As in future site remediation efforts.展开更多
Covalent organic frameworks(COFs)are promising materials for converting solar energy into green hydrogen.However,limited charge separation and transport in COFs impede their application in the photocatalytic hydrogen ...Covalent organic frameworks(COFs)are promising materials for converting solar energy into green hydrogen.However,limited charge separation and transport in COFs impede their application in the photocatalytic hydrogen evolution reaction(HER).In this study,the intrinsically tunable internal bond electric field(IBEF)at the imine bonds of COFs was manipulated to cooperate with the internal molecular electric field(IMEF)induced by the donor-acceptor(D-A)structure for an efficient HER.The aligned orientation of IBEF and IMEF resulted in a remarkable H_(2) evolution rate of 57.3 mmol·g^(-1)·h^(-1)on TNCA,which was approximately 520 times higher than that of TCNA(0.11 mmol·g^(-1)·h^(-1))with the opposing electric field orientation.The superposition of the dual electric fields enables the IBEF to function as an accelerating field for electron transfer,kinetically facilitat-ing the migration of photogenerated electrons from D to A.Furthermore,theoretical calculations indicate that the inhomogeneous charge distribution at the C and N atoms in TNCA not only pro-vides a strong driving force for carrier transfer but also effectively hinders the return of free elec-trons to the valence band,improving the utilization of photoelectrons.This strategy of fabricating dual electric fields in COFs offers a novel approach to designing photocatalysts for clean energy synthesis.展开更多
A model of continuous-time insider trading in which a risk-neutral in-sider possesses two imperfect correlated signals of a risky asset is studied.By conditional expectation theory and filtering theory,we first establ...A model of continuous-time insider trading in which a risk-neutral in-sider possesses two imperfect correlated signals of a risky asset is studied.By conditional expectation theory and filtering theory,we first establish three lemmas:normal corre-lation,equivalent pricing and equivalent profit,which can guarantee to turn our model into a model with insider knowing full information.Then we investigate the impact of the two correlated signals on the market equilibrium consisting of optimal insider trading strategy and semi-strong pricing rule.It shows that in the equilibrium,(1)the market depth is constant over time;(2)if the two noisy signals are not linerly correlated,then all private information of the insider is incorporated into prices in the end while the whole information on the asset value can not incorporated into prices in the end;(3)if the two noisy signals are linear correlated such that the insider can infer the whole information of the asset value,then our model turns into a model with insider knowing full information;(4)if the two noisy signals are the same then the total ex ant profit of the insider is increasing with the noise decreasing,while down to O as the noise going up to infinity;(5)if the two noisy signals are not linear correlated then with one noisy signal fixed,the total ex ante profit of the insider is single-peaked with a unique minimum with respect to the other noisy signal value,and furthermore as the noisy value going to O it gets its maximum,the profit in the case that the real value is observed.展开更多
Electromagnetic holographic data are characterized by two modes, suggesting that image reconstruction requires a dual-mode sensitivity field as well. We analyze an electromagnetic holographic field based on tomography...Electromagnetic holographic data are characterized by two modes, suggesting that image reconstruction requires a dual-mode sensitivity field as well. We analyze an electromagnetic holographic field based on tomography theory and Radon inverse transform to derive the expression of the electromagnetic holographic sensitivity field （EMHSF）. Then, we apply the EMHSF calculated by using finite-element methods to flow simulations and holographic imaging. The results suggest that the EMHSF based on the partial derivative of radius of the complex electric potential φ is closely linked to the Radon inverse transform and encompasses the sensitivities of the amplitude and phase data. The flow images obtained with inversion using EMHSF better agree with the actual flow patterns. The EMHSF overcomes the limitations of traditional single-mode sensitivity fields.展开更多
Based on the microscopic phase-field model, ordered domain interfaces formed between D022 （Ni3V） phases along [001] direction in Ni75AlxV25-x alloys were simulated, and the effects of atomic structure on the migrati...Based on the microscopic phase-field model, ordered domain interfaces formed between D022 （Ni3V） phases along [001] direction in Ni75AlxV25-x alloys were simulated, and the effects of atomic structure on the migration characteristic and solute segregation of interfaces were studied. It is found that the migration ability is related to the atomic structure of interfaces, and three kinds of interfaces can migrate except the interface （001）//（002） which has the characteristic of L12 （Ni3Al） structure. V atoms jump to the nearest neighbor site and substitute for Ni, and vice versa. Because of the site selectivity behaviors of jumping atoms, the number of jumping atoms during the migration is the least and the jumping distance of atoms is the shortest among all possible modes, and the atomic structures of interfaces are unchanged before and after the migration. The preferences and degree of segregation or depletion of alloy elements are also related to the atomic structure of interface.展开更多
Aim To analyse the static temperature field ofthe solid rubber tire(SRT).Methods The mechanical and thermal FE models were developed and analyzed respectively with the FE software ANSYS.Results The maximum temperature...Aim To analyse the static temperature field ofthe solid rubber tire(SRT).Methods The mechanical and thermal FE models were developed and analyzed respectively with the FE software ANSYS.Results The maximum temperature becomes higher with the higher with the higher velocity of tire and scales down slightly with the higher convection coefficients.The mixed models are reasonable.Conclusion The study on static temperature field is important and reasonable.It gives the fundament for life analysis of SRT.展开更多
基金supported by the Fundamental Research Funds for the Central Universities(WK2030000036)the National Natural Science Foundation of China(12075233).
文摘The Wilson coefficients of the standard model effective field theory are subject to a series of positivity bounds.It has been shown that while the positivity part of the ultraviolet(UV)partial wave unitarity leads to the Wilson coefficients living in a convex cone,further including the nonpositivity part caps the cone from above.For Higgs scattering,a capped positivity cone was obtained using a simplified,linear unitarity condition without utilizing the full internal symmetries of Higgs scattering.Here,we further implement stronger nonlinear unitarity conditions from the UV,which generically gives rise to better bounds.We show that,for the Higgs case in particular,while the nonlinear unitarity conditions per se do not enhance the bounds,the fuller use of the internal symmetries do shrink the capped positivity cone significantly.
基金financially supported from the National Key Research and Development Program of China(No.2019YFC1803601)the Fundamental Research Funds for the Central Universities of Central South University,China(No.2023ZZTS0801)+1 种基金the Postgraduate Innovative Project of Central South University,China(No.2023XQLH068)the Postgraduate Scientific Research Innovation Project of Hunan Province,China(No.QL20230054)。
文摘A general prediction model for seven heavy metals was established using the heavy metal contents of 207soil samples measured by a portable X-ray fluorescence spectrometer(XRF)and six environmental factors as model correction coefficients.The eXtreme Gradient Boosting(XGBoost)model was used to fit the relationship between the content of heavy metals and environment characteristics to evaluate the soil ecological risk of the smelting site.The results demonstrated that the generalized prediction model developed for Pb,Cd,and As was highly accurate with fitted coefficients(R^(2))values of 0.911,0.950,and 0.835,respectively.Topsoil presented the highest ecological risk,and there existed high potential ecological risk at some positions with different depths due to high mobility of Cd.Generally,the application of machine learning significantly increased the accuracy of pXRF measurements,and identified key environmental factors.The adapted potential ecological risk assessment emphasized the need to focus on Pb,Cd,and As in future site remediation efforts.
文摘Covalent organic frameworks(COFs)are promising materials for converting solar energy into green hydrogen.However,limited charge separation and transport in COFs impede their application in the photocatalytic hydrogen evolution reaction(HER).In this study,the intrinsically tunable internal bond electric field(IBEF)at the imine bonds of COFs was manipulated to cooperate with the internal molecular electric field(IMEF)induced by the donor-acceptor(D-A)structure for an efficient HER.The aligned orientation of IBEF and IMEF resulted in a remarkable H_(2) evolution rate of 57.3 mmol·g^(-1)·h^(-1)on TNCA,which was approximately 520 times higher than that of TCNA(0.11 mmol·g^(-1)·h^(-1))with the opposing electric field orientation.The superposition of the dual electric fields enables the IBEF to function as an accelerating field for electron transfer,kinetically facilitat-ing the migration of photogenerated electrons from D to A.Furthermore,theoretical calculations indicate that the inhomogeneous charge distribution at the C and N atoms in TNCA not only pro-vides a strong driving force for carrier transfer but also effectively hinders the return of free elec-trons to the valence band,improving the utilization of photoelectrons.This strategy of fabricating dual electric fields in COFs offers a novel approach to designing photocatalysts for clean energy synthesis.
文摘A model of continuous-time insider trading in which a risk-neutral in-sider possesses two imperfect correlated signals of a risky asset is studied.By conditional expectation theory and filtering theory,we first establish three lemmas:normal corre-lation,equivalent pricing and equivalent profit,which can guarantee to turn our model into a model with insider knowing full information.Then we investigate the impact of the two correlated signals on the market equilibrium consisting of optimal insider trading strategy and semi-strong pricing rule.It shows that in the equilibrium,(1)the market depth is constant over time;(2)if the two noisy signals are not linerly correlated,then all private information of the insider is incorporated into prices in the end while the whole information on the asset value can not incorporated into prices in the end;(3)if the two noisy signals are linear correlated such that the insider can infer the whole information of the asset value,then our model turns into a model with insider knowing full information;(4)if the two noisy signals are the same then the total ex ant profit of the insider is increasing with the noise decreasing,while down to O as the noise going up to infinity;(5)if the two noisy signals are not linear correlated then with one noisy signal fixed,the total ex ante profit of the insider is single-peaked with a unique minimum with respect to the other noisy signal value,and furthermore as the noisy value going to O it gets its maximum,the profit in the case that the real value is observed.
基金supported by the National Science and Technology Major Project(No.2011ZX05020-006)
文摘Electromagnetic holographic data are characterized by two modes, suggesting that image reconstruction requires a dual-mode sensitivity field as well. We analyze an electromagnetic holographic field based on tomography theory and Radon inverse transform to derive the expression of the electromagnetic holographic sensitivity field （EMHSF）. Then, we apply the EMHSF calculated by using finite-element methods to flow simulations and holographic imaging. The results suggest that the EMHSF based on the partial derivative of radius of the complex electric potential φ is closely linked to the Radon inverse transform and encompasses the sensitivities of the amplitude and phase data. The flow images obtained with inversion using EMHSF better agree with the actual flow patterns. The EMHSF overcomes the limitations of traditional single-mode sensitivity fields.
基金Projects (50941020, 10902086, 50875217, 20903075) supported by the National Natural Science Foundation of ChinaProjects (SJ08-ZT05, SJ08-B14) supported by the Natural Science Foundation of Shaanxi Province, ChinaProject (CX200905) supported by the Doctorate Foundation of Northwestern Polytechnical University, China
文摘Based on the microscopic phase-field model, ordered domain interfaces formed between D022 （Ni3V） phases along [001] direction in Ni75AlxV25-x alloys were simulated, and the effects of atomic structure on the migration characteristic and solute segregation of interfaces were studied. It is found that the migration ability is related to the atomic structure of interfaces, and three kinds of interfaces can migrate except the interface （001）//（002） which has the characteristic of L12 （Ni3Al） structure. V atoms jump to the nearest neighbor site and substitute for Ni, and vice versa. Because of the site selectivity behaviors of jumping atoms, the number of jumping atoms during the migration is the least and the jumping distance of atoms is the shortest among all possible modes, and the atomic structures of interfaces are unchanged before and after the migration. The preferences and degree of segregation or depletion of alloy elements are also related to the atomic structure of interface.
文摘Aim To analyse the static temperature field ofthe solid rubber tire(SRT).Methods The mechanical and thermal FE models were developed and analyzed respectively with the FE software ANSYS.Results The maximum temperature becomes higher with the higher with the higher velocity of tire and scales down slightly with the higher convection coefficients.The mixed models are reasonable.Conclusion The study on static temperature field is important and reasonable.It gives the fundament for life analysis of SRT.
