lattice expansion
1.The experimental results indicate that a near zero thermal expansion ceramic with good thermal shock resistance performance can be attained by adjusting x value,it is KSr 1/2 Zr 4P 6O 24 ,which have near zero expansion as well as near zero anisotropy in the lattice thermal expansion,its liner ecpansion coefficients a 20/1000 =0.8×10 -6 /℃.
2.The complete photonic band gap in two-dimensional chessboard of non-Bravais lattice is calculated by the plane wave expansion method. The result shows that a gap width to midgap frequency ratio Δω/ω of chessboard non-Bravais lattice is almost 5 times that of the ordinary chessboard lattice, and the number of complete photonic band gaps is increased.
4.By gaining the moment equations from lattice Boltzmann equation and using Chapman-Enskog expansion, the fluid dynamices equation and energy equation of 13-bit lattice gas automata model with polyvelocity have been deduced. The validity of the model using for non-isothermal fluid dynamics has been proved.
7.A Laplace expansion formula for the determinant of lattice matrices is given. The relationship of a lattice matrice with its adjoint matrice and determinant is studied. Using determinant of lattice matrices, the Cramer rule of linear equation group,which takes the lattice element as its coefficient, is presented, also.
9.Using the modified analytic EAM (MAEAM) potentials proposed by Hu et al and lattice dynamics method, the universe physical properties (such as phonon spectra, state density, specific heat, Debye temperature, Griinsisen constant and expansion coefficient) are studied systematically, and compared with experimental data.
10.The structural and thermodynamic properties of zinc-blende phase of GaN have been investigated systematically using the molecular dynamics method with Buckingham potential model. These properties including lattice constant, phase transition pressure (from the zinc-blende to the rock-salt structure), thermal expansion, isothermal bulk modulus, and heat capacity at constant pressure were calculated in a wide range of temperatures (300—3000?K) and pressures (0—65?GPa).
