利用强子探针研究奇特原子核的点质子分布半径及强子探针效应

We report the charge-changing cross sections(σ_(cc))of 24 p-shell nuclides on both hydrogen and carbon at about 900A MeV,of which^(8,9)Li,^(10–12)Be,^(10,14,15)B,^(14,15,17–22)N and^(16)O on hydrogen and^(8,9)Li on carbon are for the first time.Benefiting from the data set,we found a new and robust relationship between the scaling factor of the Glauber model calculations and the separation energies of the nuclei of interest on both targets.This allows us to deduce proton radii(R_p)for the first time from the cross sections on hydrogen.Nearly identical R_p values are deduced from both target data for the neutron-rich carbon isotopes;however,the R_p from the hydrogen target is systematically smaller in the neutron-rich nitrogen isotopes.This calls for further experimental and theoretical investigations.

Influence of nuclear physics inputs and astrophysical conditions on r-process

The rapid neutron-capture process(r-process) is one of the main mechanisms to explain the origin of heavy elements in the universe. Although the past decades have seen great progress in understanding this process, the related nuclear physics inputs to r-process models include significant uncertainty. In this study, ten nuclear mass models, including macroscopic, macroscopicmicroscopic, and microscopic models, are used to calculate the β-decay rates and neutron-capture rates of the neutron-rich isotopes for the r-process simulations occurring in three classes of astrophysical conditions. The final r-process abundances include uncertainties introduced by the nuclear mass model mainly through the variation of neutron-capture rates, whereas the uncertainties of β-decay rates make a relatively small contribution. The uncertainties in different astrophysical scenarios are also investigated,and are found to be connected to the diverse groups of nuclei produced during nucleosynthesis.

High precision nuclear mass predictions towards a hundred kilo-electron-volt accuracy

Mass is a fundamental property and an important fingerprint of atomic nucleus.It provides an extremely useful test ground for nuclear models and is crucial to understand energy generation in stars as well as the heavy elements synthesized in stellar explosions.Nuclear physicists have been attempting at developing a precise,reliable,and predictive nuclear model that is suitable for the whole nuclear chart,while this still remains a great challenge even in recent days.Here we employ the Fourier spectral analysis to examine the deviations of nuclear mass predictions to the experimental data and to present a novel way for accurate nuclear mass predictions.In this analysis,we map the mass deviations from the space of nucleon number to its conjugate space of frequency,and are able to pin down the main contributions to the model deficiencies.By using the radial basis function approach we can further isolate and quantify the sources.Taking a pedagogical mass model as an example,we examine explicitly the correlation between nuclear effective interactions and the distributions of mass deviations in the frequency domain.The method presented in this work,therefore,opens up a new way for improving the nuclear mass predictions towards a hundred kilo-electron-volt accuracy,which is argued to be the chaos-related limit for the nuclear mass predictions.

Game Theoretical Approach for Non-Overlapping Community Detection

Graph clustering,i.e.,partitioning nodes or data points into non-overlapping clusters,can be beneficial in a large varieties of computer vision and machine learning applications.However,main graph clustering schemes,such as spectral clustering,cannot be applied to a large network due to prohibitive computational complexity required.While there exist methods applicable to large networks,these methods do not offer convincing comparisons against known ground truth.For the first time,this work conducts clustering algorithm performance evaluations on large networks(consisting of one million nodes)with ground truth information.Ideas and concepts from game theory are applied towards graph clustering to formulate a new proposed algorithm,Game Theoretical Approach for Clustering(GTAC).This theoretical framework is shown to be a generalization of both the Label Propagation and Louvain methods,offering an additional means of derivation and analysis.GTAC introduces a tuning parameter which allows variable algorithm performance in accordance with application needs.Experimentation shows that these GTAC algorithms offer scalability and tunability towards big data applications.

A compact ultra-wideband crossed-dipole antenna for 2G/3G/4G/IMT/5G customer premise equipment applications

1 Introduction A compact ultra-wideband crossed-dipole antenna is proposed for 2G/3G/4G/IMT/5G customer premise equipment(CPE)applications.The arms of the crossed-dipole antenna are formed by step-shaped patches,and a wideband operation can be realized by properly selecting the order of the step-shaped patches;its bandwidth can be further enhanced by extending the end of crossed dipole downward.Each dipole is excited by a microstrip stub that is directly connected to a coaxial cable.Furthermore,a slotted rectangular parasitic patch is added beneath the crossed dipoles to further support a 5G sub-6-GHz band without additional space cost.

A novel wideband ring antenna for polarization/pattern diversity

We present a novel wideband ring antenna for polarization/pattern diversity.The proposed antenna consists of eight printed dipole elements in the form ofacircular array.The arms of adjacent elements overlap for capacitive loading Unlike traditional circular arrays,a method of exciting elements in the form of every two intervals is first introduced.