中文摘要：

在北京同步辐射装置（BSRF）高压站对采自于河北大麻坪的天然顽火辉石,在室温高压（0～31.64 GPa）下,利用金刚石压腔装置（DAC）,进行了能量色散X射线粉末衍射（EDXD）原位测量,得到了顽火辉石在不同压力下的衍射图谱,并利用UnitCell软件进行解谱,获得了其晶胞参数a、bc、和晶胞体积V及其随压力的变化,最后利用Murnaghan等温方程得到了天然顽火辉石的体积模量KT（0）=172 GPa、压缩系数及p-V状态方程,发现沿a、b、c三方向的压缩系数存在明显的各向异性,结果与斜方辉石的弹性波速各向异性完全一致。

英文摘要：

　Using synchrotron radiation and diamond anvil cell（DAC） in high pressure research station of Beijing Synchrotron Radiation Facility（BSRF）,energy dispersive X-ray powder diffraction（EDXD） of the natural enstatite collected from Damapin in Hebei Province,have been in situ measured under room temperature and high pressure（0～31.64 GPa） conditions.Then the unit-cell parameters of sample and their changes versus pressure have been acquired using the UnitCell software.Furthermore,basing on Murnaghan equation of state（EOS）,bulk modulus KT（0）=172 GPa,compression coefficient,and p-V equation of state of natural enstatite have been obtained.The experiment data show that compression coefficient have distinct anisotropy for the three crystallographic axis.This result is consistent with the anisotropy of elastic velocity of orthopyroxene.