The liquid structure of pure iron at 1540, 1560 and 1580 deg C was studied byX-ray diffraction. The results show that near the melting point there is a medium-range orderstructure that fades away with the increasing t...The liquid structure of pure iron at 1540, 1560 and 1580 deg C was studied byX-ray diffraction. The results show that near the melting point there is a medium-range orderstructure that fades away with the increasing temperature. The average nearest distance of atoms isalmost independent of the melts temperature, but the average coordination number, the atom clustersize and the atom number in an atom cluster all decrease with the increasing temperature of themelt. Near the melting point there are a lot of atom clusters in the pure iron melt. The atomcluster of pure iron has the body-centered cubic lattices, which are kept from the solid state. Andthe body-centered cubic lattices connect into network by occupying a same edge. The atoms in thesurrounding of the atom clusters are arranged disorderly.展开更多
For each positive integer k,the radix representation of the complex numbers in the base -k+i gives rise to a lattice self-affine tile T_k in the plane,which consists of all the complex numbers that can be expressed in...For each positive integer k,the radix representation of the complex numbers in the base -k+i gives rise to a lattice self-affine tile T_k in the plane,which consists of all the complex numbers that can be expressed in the form∑_(j≥1)d_j(-k+i)^(-j),where d_j∈{0,1,2,...,k^2}.We prove that T_k is homeomorphic to the closed unit disk{z∈C:|z|≤1}if and only if k≠2.展开更多
基金This work was financially supported by the National Natural Science Foundation of China (No.59974003)"973" Research Foundation of the Science and Technology Ministry of China (No. G199806150402)
文摘The liquid structure of pure iron at 1540, 1560 and 1580 deg C was studied byX-ray diffraction. The results show that near the melting point there is a medium-range orderstructure that fades away with the increasing temperature. The average nearest distance of atoms isalmost independent of the melts temperature, but the average coordination number, the atom clustersize and the atom number in an atom cluster all decrease with the increasing temperature of themelt. Near the melting point there are a lot of atom clusters in the pure iron melt. The atomcluster of pure iron has the body-centered cubic lattices, which are kept from the solid state. Andthe body-centered cubic lattices connect into network by occupying a same edge. The atoms in thesurrounding of the atom clusters are arranged disorderly.
基金The first author is supported by Youth Project of Tianyuan Foundation(10226031)zhongshan University Promotion Foundation for Young Teachers (34100-1131206)+1 种基金the second author is supported by National science Foundation(10041005)Guangdong Provic
文摘For each positive integer k,the radix representation of the complex numbers in the base -k+i gives rise to a lattice self-affine tile T_k in the plane,which consists of all the complex numbers that can be expressed in the form∑_(j≥1)d_j(-k+i)^(-j),where d_j∈{0,1,2,...,k^2}.We prove that T_k is homeomorphic to the closed unit disk{z∈C:|z|≤1}if and only if k≠2.
