The non-equilibrium molecular dynamics method is adapted to calculate the phonon thermal conductivity of alphazirconium. By exchanging velocities of atoms in different regions, the stable heat flux and the temperature...The non-equilibrium molecular dynamics method is adapted to calculate the phonon thermal conductivity of alphazirconium. By exchanging velocities of atoms in different regions, the stable heat flux and the temperature gradient are established to calculate the thermal conductivity. The phonon thermal conductivities under different conditions, such as different heat exchange frequencies, different temperatures, different crystallographic orientations, and crossing grain boundary （GB）, are studied in detail with considering the finite size effect. It turns out that the phonon thermal conductivity decreases with the increase of temperature, and displays anisotropies along different crystallographic orientations. The phonon thermal conductivity in [0001] direction （close-packed plane） is largest, while the values in other two directions of [2īī0] and [01ī0] are relatively close. In the region near GB, there is a sharp temperature drop, and the phonon thermal conductivity is about one-tenth of that of the single crystal at 550 K, suggesting that the GB may act as a thermal barrier in the crystal.展开更多
基金the National Basic Research Program of China(Grant No.2010CB731601)
文摘The non-equilibrium molecular dynamics method is adapted to calculate the phonon thermal conductivity of alphazirconium. By exchanging velocities of atoms in different regions, the stable heat flux and the temperature gradient are established to calculate the thermal conductivity. The phonon thermal conductivities under different conditions, such as different heat exchange frequencies, different temperatures, different crystallographic orientations, and crossing grain boundary （GB）, are studied in detail with considering the finite size effect. It turns out that the phonon thermal conductivity decreases with the increase of temperature, and displays anisotropies along different crystallographic orientations. The phonon thermal conductivity in [0001] direction （close-packed plane） is largest, while the values in other two directions of [2īī0] and [01ī0] are relatively close. In the region near GB, there is a sharp temperature drop, and the phonon thermal conductivity is about one-tenth of that of the single crystal at 550 K, suggesting that the GB may act as a thermal barrier in the crystal.
文摘通过挤出注塑工艺制备了α-磷酸锆(α-Zr P)改性的热塑性淀粉塑料,研究了不同含量的α-Zr P对其拉伸强度、冲击强度、耐水及转矩流变性能的影响。结果表明,当α-Zr P含量为0.2%时,淀粉塑料的拉伸强度从未加时的1.94 MPa达到最高的4.5 MPa,断裂伸长率有所下降;冲击强度由50.4 k J/m2增加到55.32 k J/m2;表面接触角由46.34°增加到70.46°,耐水性改善明显;转矩流变曲线表明此时具有较高的峰值扭矩,加工性能有所下降。
