The instanton induced cross section in deep inelastic kinematics is a subject which people are tendentious to investigate it. Instanton induced contributions are well defined for the nucleon structure function. The no...The instanton induced cross section in deep inelastic kinematics is a subject which people are tendentious to investigate it. Instanton induced contributions are well defined for the nucleon structure function. The non-perturbative contribution to the quark distributions of structure function, F2（x, Q2）, is considered within an instanton model for the QCD vacuum. We find that the structure function may possess numerically large non-perterbative contributions which are related to the violation of chirality and correspond to the correction of parton distribution of the leading twist. It is shown that the instantons give a negative contribution to the structure function at the NLO approximation. A comparison between our results, considering instantaon effect, and the case when we do not take this effect is done. Taking into account the instanton size, p, via the modified running coupling constant we get to a good agreement between our results at the NLO and NNLO approximations and the available experimental data, specially at the low values of the Bjorken variable x 〈 0.1 which confirms the validity of our calculations.展开更多
Particle motion in confined shear flow of viscoelastic fluids is very common in nature and has a wide range of applications.Understanding and mastering the motion characteristics of particles in viscoelastic fluids ha...Particle motion in confined shear flow of viscoelastic fluids is very common in nature and has a wide range of applications.Understanding and mastering the motion characteristics of particles in viscoelastic fluids has important academic value and practical significance.In this paper,we first introduce the related equations and characteristic parameter,and then emphasize the following issues:the lateral equilibrium position of particle;interaction and aggregation of multiple particles;the chain structure formed by multiple particles;and the motion of non-spherical particle.Finally,some unresolved issues,challenges,and future research directions are highlighted.展开更多
文摘The instanton induced cross section in deep inelastic kinematics is a subject which people are tendentious to investigate it. Instanton induced contributions are well defined for the nucleon structure function. The non-perturbative contribution to the quark distributions of structure function, F2（x, Q2）, is considered within an instanton model for the QCD vacuum. We find that the structure function may possess numerically large non-perterbative contributions which are related to the violation of chirality and correspond to the correction of parton distribution of the leading twist. It is shown that the instantons give a negative contribution to the structure function at the NLO approximation. A comparison between our results, considering instantaon effect, and the case when we do not take this effect is done. Taking into account the instanton size, p, via the modified running coupling constant we get to a good agreement between our results at the NLO and NNLO approximations and the available experimental data, specially at the low values of the Bjorken variable x 〈 0.1 which confirms the validity of our calculations.
基金supported by the National Natural Science Foundation of China(Grant No.11632016).
文摘Particle motion in confined shear flow of viscoelastic fluids is very common in nature and has a wide range of applications.Understanding and mastering the motion characteristics of particles in viscoelastic fluids has important academic value and practical significance.In this paper,we first introduce the related equations and characteristic parameter,and then emphasize the following issues:the lateral equilibrium position of particle;interaction and aggregation of multiple particles;the chain structure formed by multiple particles;and the motion of non-spherical particle.Finally,some unresolved issues,challenges,and future research directions are highlighted.
