地球深部物质的某些物性测量方法研究

SOME EXPERIMENTAL METHODS FOR DETERMINING PHYSICAL PROPERTIES OF MATERIALS IN THE EARTH'S INTERIOR

文中介绍了地球深部物质实验室近 2 0年来开展高温高压下地球深部物质物性实验研究过程中 ,在测量方法方面的进步和应用情况。这些测量方法包括了高温、高压下弹性的超声测量方法、高温高压下电性的测量方法、高压差热分析法和高压下热学Gr櫣ｎｅｉｓｅｎ参数的测量方法诟呶赂哐瓜卵沂涂笪锏牡猿饬恐?,我们由超声脉冲透射方法改进为超声脉冲透射反射法 ,克服了样品室中压力和温度梯度对样品的影响。在高温高压下岩石和矿物的电学性质测量中 ,我们由直流法发展为阻抗谱法 ,不仅克服了样品极化对测量结果的影响 ,还可以获得离子在溶液中的多种物理化学参数 ,以及监测含水矿物在高温高压下的脱水动力学特征。在固体传压介质中建立的高压热学Gr櫣ｎｅｉｓｅｎ参数的测量方法 ,由于升压速率比较小且叶蜡石在高压下的热导系数增大 ,其测量结果需要进行校正 ,其测量方法有待进一步改进。

In the recent two decades, four experimental methods have developed by the Material Laboratory of the Earth's Interior, Institute of Geochemistry, Chinese Academy of Science, for determining physical properties of materials in the earth's interior at high pressure and high temperature in the multi\|anvil apparatus. They are the ultrasonic method for measuring the elastic wave velocities in mineral and rock;the electrical method for measuring the electrical conductivities in mineral, rock and fluid; the differential thermal analysis method; and the method for measuring the Grüneisen parameter of thermodynamics.We have improved the ultrasonic method of measuring the elastic wave velocities for mineral and rock at high temperature and high pressure by using the reflection\|transmission combined method. Comparing with the ultrasonic transmission method, the reflection\|transmission method averts the influence of temperature gradient and pressure gradient in the chamber of sample. We have developed the impedance spectroscopy analysis method for determining the electrical properties. This method not only avoids polarization of the measured sample on the measuring results but also obtains some physical and chemical parameters of ion in solution. Furthermore, it can be used to monitor the mineral dehydration process at high temperature and high pressure. Using a quasi\|adiabatic method when the pyrophyllite is used as pressure medium, and measuring the temperature change in the compressive process, we can directly determine the Grüneisen parameter of thermodynamics in materials. Because of the relatively slow rate of the pressure rising and the high thermal conductivity of pyrophyllite at high pressure, the measured results of the Grüneisen parameter have to be corrected. The method for determining the Grüneisen parameter wants to be improved further.