The superheated Melting of Grain Boundary

Based on a model of the melting of Grain Boundary (GB), we discuss the possibility of the existence of superheated GB state. A Molecular Dynamics simulation presented here shows that the superheated GB state can realized in the high symmetric tilt GB. Whether the sizes of liquid nuclei exceed a critical size determined the superheating grain boundary melting or not. Our results also indicate that the increase of melting point due to pressure is smaller than the superheating due to nucleation mechanism.Comment: Accepted by PRB, 7 pages and 5 figure

The Three-body Force and the Tetraquark Interpretation of Light Scalar Mesons

We study the possible tetraquark interpretation of light scalar meson states $a_0(980)$, $f_0(980)$, $\kappa$, $\sigma$ within the framework of the non-relativistic potential model. The wave functions of tetraquark states are obtained in a space spanned by multiple Gaussian functions. We find that the mass spectra of the light scalar mesons can be well accommodated in the tetraquark picture if we introduce a three-body quark interaction in the quark model. Using the obtained multiple Gaussian wave functions, the decay constants of tetraquarks are also calculated within the ``fall apart'' mechanism

The Tensor Current Divergence Equation in U(1) Gauge Theories is Free of Anomalies

The possible anomaly of the tensor current divergence equation in U(1) gauge theories is calculated by means of perturbative method. It is found that the tensor current divergence equation is free of anomalies.Comment: Revtex4, 7 pages, 2 figure

Hierarchical Metal‐Organic Network‐Forming Glasses toward Applications

Glassy states of network-forming coordination polymers (CPs) and metal-organic frameworks (MOFs) represent a novel category of amorphous materials. Recent years have seen substantial progress in expanding the compound library and advancing the structural design of CP/MOF glasses. This review examines the current status and future potential of multi-scale hierarchical CP/MOF glass materials, covering synthesis, shape adaptability, and synergistic materials. Extensive experimental and theoretical investigations of structure-property relationships have shed light on their diverse utility, spanning areas such as permanent porosity and gas permeability, ionic and electronic conductivity, optics, catalysis, and battery technology. Additionally, the inherent properties of these glasses, coupled with their phase transformation capability, enable a range of morphological architectures. Current challenges are also addressed and offer insights into future research, with the goal of bringing CP/MOF glasses to the industry

The X-ray emission lines in GRB afterglows: the evidence for the two-component jet model

Recently, X-ray emission lines have been observed in X-ray afterglows of several $\gamma$-ray bursts. It is a major breakthrough for understanding the nature of the progenitors. It is proposed that the X-ray emission lines can be well explained by the Geometry-Dominated models, but in these models the illuminating angle is much larger than that of the collimated jet of the $\gamma$-ray bursts(GRBs). For GRB 011211, we obtain the illuminating angle is about $\theta\sim45^{\circ}$, while the angle of GRB jet is only $3.6^{\circ}$, so we propose that the outflow of the GRBs with emission lines should have two distinct components. The wide component illuminates the reprocessing material, and produces the emission lines, while the narrow one produces the $\gamma$-ray bursts. The observations show that the energy for producing the emission lines is higher than that of the GRBs. In this case, when the wide component dominates the afterglows, a bump will appear in the GRBs afterglows. For GRB 011211, the emergence time of the bump is less than 0.05 days after the GRB, it is obviously too early for the observation to catch it. With the presence of the X-ray emission lines there should also be a bright emission component between the UV and the soft X-rays. These features can be tested by the $Swift$ satellite in the near future.Comment: 10 pags, 1 figure, ChJAA in pres

The effects of reciprocal cross on inheritance of DNA methylation in cotton (Gossypium hirsutum)

DNA methylation plays an important role for regulation of gene expression. To study the inheritance of DNA methylation, we selected two F1 plant population by reciprocal cross with two cotton lines Zongcaixuan No.1 and HY428, and analyzed the variations of DNA methylation levels and patterns in F1 generations by methylation sensitive amplified fragment length polymorphism (MSAP) technique with 54 primer combinations. The results show that most cytosine methylated patterns are conservatively inherited from parents. The numbers of variant sites are less in F1 generation. According to the number of sites individually inherited from female and male parents, the different choice of female and male parents made a big distinction between the sites inherited from female parent and the sites inherited from the male parent. For reciprocal cross F113 and F132, the number for sites of cytosine methylation patterns inherited from the female parent are far more than that from the male parent, which may be closely related to cytoplasmic inheritance.Key words: Methylation sensitive amplified fragment length polymorphism (MSAP), DNA methylation, cytoplasmic inheritance, reciprocal cross, cotton

Polarization evolution accompanying the very early sharp decline of GRB X-ray afterglows

In the synchrotron radiation model, the polarization property depends on both the configuration of the magnetic field and the geometry of the visible emitting region. Some peculiar behaviors in the X-ray afterglows of {\it Swift} gamma-ray bursts (GRBs), such as energetic flares and the plateau followed by a sharp drop, might by highly linearly-polarized because the outflows powering these behaviors may be Poynting-flux dominated. Furthermore, the broken-down of the symmetry of the visible emitting region may be hiding in current X-ray data and will give rise to interesting polarization signatures. In this work we focus on the polarization accompanying the very early sharp decline of GRB X-ray afterglows. We show that strong polarization evolution is possible in both the high latitude emission model and the dying central engine model which are used to interpret this sharp X-ray decline. It is thus not easy to efficiently probe the physical origin of the very early X-ray sharp decline with future polarimetry. Strong polarization evolution is also possible in the decline phase of X-ray flares and in the shallow decline phase of X-ray light curves characterized by chromatic X-ray VS. Optical breaks. An {\it XRT}-like detector but with polarization capability on board a {\em Swift}-like satellite would be suitable to test our predictions.Comment: 9 pages including 4 figures. Accepted for publication in MNRAS, typos correcte

Design and durability analysis of marine concrete

Marine engineering is an important way for a country to go deep blue. In the marine environment, there are many factors that affect the durability of concrete, among which the most harmful one is chloride ion erosion. In order to improve the ability to resist chloride ion permeation, this paper designs, compares and selects the appropriate water cement ratio of marine concrete, with the use of new anticorrosive technologies such as epoxy coating and silane impregnation. The design service life and the chloride ion diffusion coefficient prediction are analysed by establishing models, and this paper verifies whether the engineering design meets the service life requirement