Neutron skin thickness of 90Zr and symmetry energy constrained by charge exchange spin-dipole excitations

The charge exchange spin-dipole (SD) excitations of \begin{document}$ ^{90} $\end{document}Zr are studied using the Skyrme Hartee-Fock plus proton-neutron random phase approximation with SAMi-J interactions. The experimental value of the model-independent sum rule obtained from the SD strength distributions of \begin{document}$ ^{90} $\end{document}Zr(p, n)\begin{document}$ ^{90} $\end{document}Nb and \begin{document}$ ^{90} $\end{document}Zr(n, p)\begin{document}$ ^{90} $\end{document}Y is used to deduce the neutron skin thickness. The neutron skin thickness \begin{document}$ \Delta r_{np} $\end{document} of \begin{document}$ ^{90} $\end{document}Zr is extracted as \begin{document}$ 0.083\pm0.032 $\end{document} fm, which is similar to the results of other studies. Based on the correlation analysis of the neutron skin thickness \begin{document}$ \Delta r_{np} $\end{document} and the nuclear symmetry energy J as well as its slope parameter L, a constraint from the extracted \begin{document}$ \Delta r_{np} $\end{document} leads to the limitation of J to \begin{document}$ 29.2 \pm 2.6 $\end{document} MeV and L to \begin{document}$ 53.3 \pm 28.2 $\end{document} MeV.     

Spectral Structure and Doublon Dissociation in the Two-Particle Non-Hermitian Hubbard Model

Strongly-correlated systems in non-Hermitian models are an emergent area of research. Herein, a non-Hermitian Hubbard model is considered, where the single-particle hopping amplitudes on the lattice are not reciprocal, and provide exact analytical results of the spectral structure in the two-particle sector of Hilbert space under different boundary conditions. The analysis unveils some interesting spectral and dynamical effects of purely non-Hermitian nature and that deviate from the usual scenario found in the single-particle regime. Specifically, a spectral phase transition of the Mott-Hubbard band on the infinite lattice is predicted as the interaction energy is increased above a critical value, from an open to a closed loop in complex energy plane, and the dynamical dissociation of doublons, i.e., instability of two-particle bound states, in the bulk of the lattice, with a sudden revival of the doublon state when the two particles reach the lattice edge. Particle dissociation observed in the bulk of the lattice is a clear manifestation of non-Hermitian dynamics arising from the different lifetimes of single-particle and two-particle states, whereas the sudden revival of the doublon state at the boundaries is a striking burst edge dynamical effect peculiar to non-Hermitian systems with boundary-dependent energy spectra, here predicted for the first time for correlated particles.     

丰质子核性质的研究

用相对论平均场理论研究了2sld壳丰质子核及其镜核的性质,理论计算结果与实验数据很好地符合.     

Determination of isospin asymmetry effects on α-decay

In this study,we compared the effect of the isospin asymmetry of proton and neutron density distributions in the neutron skin-type(NST) case and in the Hartree-Fock formalism(HF) on the half-life of alpha emitters with the atomic number in the range of 82≤Z≤92.The NST case and HF formalism based on the Skyrme-SLy4 effective interaction reveal different isospin asymmetries for selected alpha emitters.Furthermore,the obtained results reveal an increase in the α-decay widths of about 30% for the NST case in comparison with the equivalent values obtained by HF formalism.The standard deviations for calculated half-lives within the NST case and HF formalism are about 0.438 and 0.391,respectively.     

Au-Au2S复合纳米球壳微粒的空腔谐振及参量讨论

Au-Au2S复合纳米球壳微粒（金纳米球壳），是一种新型复合结构的纳米微粒，其结构为纳米级的Au2S介质球外包裹了一层几个纳米厚的黄金球壳。这种复合纳米球壳微粒可以被抽象为球型谐振腔。报道了它的空腔谐振吸收的实验结果，并且运用经典理论结合介观结构特征，讨论了有关Au-Au2S复合纳米球壳微粒空腔谐振吸收的一些重要参量，其中包括谐振吸收波长、品质因数、谐振能量等。另外，还讨论了金球壳的厚度对这些重要参量的影响。     

Skin formation in drying a film of soft matter solutions:Application of solute based Lagrangian scheme

When a film of soft matter solutions is being dried, a skin layer often forms at its surface, which is a gel-like elastic phase made of concentrated soft matter solutions. We study the dynamics of this process by using the solute based Lagrangian scheme which was proposed by us recently. In this scheme, the process of the gelation(i.e., the change from sol to gel) can be naturally incorporated in the diffusion equation. Effects of the elasticity of the skin phase, the evaporation rate of the solvents, and the initial concentration of the solutions are discussed. Moreover, the condition for the skin formation is provided.     

Solution of the skin effect problem with an arbitrary coefficient of specular reflection

An analytical solution of the skin effect problem in a metal with specular-diffuse boundary conditions is obtained. A new analytical method is developed that makes it possible to obtain a solution up to an arbitrary degree of accuracy. The method is based on the idea of representing not only the boundary condition on the field in the form of a source (which is conventional) but also the boundary condition on the distribution function. The solution is obtained in the form of a von Neumann series.     

Traditional Dough in the Era of Internet of Things: Edible,Renewable, and Reconfigurable Skin‐Like Iontronics

With the rapid development of Internet of Things technology, interactive interfaces that can promote bidirectional communications between human beings and machines will certainly play an important role. Current electronic or iontronic systems meet diverse requirements such as conductivity, mechanical compliance, stimuli responsiveness, long‐time duration, and even biocompatibility. However, for future large‐scale applications, non‐degradable and non‐recyclable components in these devices cause resource waste and environmental pollution. Here, traditional dough is used to replace non‐recyclable conductive components and fabricate a type of renewable and reconfigurable smart skin. These smart skins are self‐healing, mechanically adaptable to irregular interfaces, and can sense different gestures of a prosthetic hand as well as large and subtle scale of human motion. This work greatly extends the material choice and enables new functionality for skin‐like iontronics, and may address the concern about their impact on human health and environmental issues in the era of Internet of Things.     

飞机蒙皮红外辐射的瞬态温度场分析

飞机蒙皮温度场是形成飞机红外图像的基本因素,掌握其瞬态分布特性与控制机制对于飞机相关的红外技术有重要帮助.通过分析控制蒙皮温度场的传热过程,建立了包括飞机内部换热、蒙皮外气动对流与辐射换热的瞬态耦合传热数理模型.引入壁面热流函数,将蒙皮外部热环境与飞机内部换热进行解耦计算,采用热网络法与蒙特卡罗法进行飞机内部传热分析,利用FLUENT软件进行蒙皮外气动对流换热模拟,建立了飞机蒙皮瞬态温度场的数值方法.通过模拟计算,获得了不同飞行状况下飞机蒙皮的瞬态温度场,分析了相关因素的影响.