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采用同步辐射能量色散X射线衍射技术、激光加热技术和金刚石对顶砧(DAC)高压装置,在温度为2 000 K和压力为23 GPa的范围内,对采自地幔二辉橄榄岩中的顽火斜方辉石,进行了原位的高温高压能量色散X射线衍射(EDXRD)测量。实验结果表明:当压力为15.3 GPa、温度为1 600 K时(相当于地球内部410 km处的地震波不连续界面的温压环境),顽火斜方辉石转变为橄榄石的β相——瓦兹利石(Wadsleyite)相;继续加温加压至2 000 K、23 GPa时(相当于地球内部670 km处的地震波不连续界面的温压环境),顽火斜方辉石相变为钛铁矿(Ilmenite)结构和钙钛矿(Perovskite)结构的混和相。实验结果进一步证明,在地幔中存在的两个地震波不连续界面是由橄榄石、顽火斜方辉石等矿物的相变引起的。 相似文献
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The compression behaviour of Ni77P23 amorphous alloy is investigated at room temperature in a diamond-anvil cell instrument using in-situ high pressure energy dispersive x-ray diffraction with a synchrotron radiation source. The equation of state is determined by fitting the experimental data according to the Birch-Murnaghan equation. It is found that the structure of Ni77P23 amorphous alloy is stable under pressures up to 30.5 GPa. Within the pressure range from zero to the experimental one, the pressure-induced structural relaxation is reversible. 相似文献
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In-situ energy dispersive x-ray diffraction on ZnS nanocrystalline was carried out under high pressure by using a diamond anvil cell. Phase transition of wurtzite of 10nm ZnS to rocksalt occurred at 16.0GPa, which was higher than that of the bulk materials. The structures of ZnS nanocrystalline at different pressures were built by using materials studio and the bulk modulus, and the pressure derivative of ZnS nanocrystalline were derived by fitting the equation of Birch-Murnaghan. The resulting modulus was higher than that of the corresponding bulk material, which indicates that the nanomaterial has higher hardness than its bulk materials. 相似文献
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A novel power generator has been achieved to convert vibration to electrical energy via the piezoelectric effect. The generator obtained by micro fabrication process mainly consists of silicon based frame and composite cantilever. The prototype tested at resonant vibration generates 1.15μW of effective power to a 20.4-kΩ resistance load. The potential of this work is to offer miniaturization solutions for power generators, and with the proposed method the ambient ubiquitous vibration can be harvested effectively as endless energy source to form an integrated self-powering system. 相似文献
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利用布朗动力学方法研究了ACB三嵌段粒子的分级自组装过程.由第一级组装得到的结构作为第二级组装的初始构型,通过调控体系中补丁B部分的吸引强度和补丁粒子的浓度,研究了第二级组装过程中形成有序结构的影响因素.通过设计组装模型、组装规则和组装路线,得到了蜂巢状网络结构和金刚石状结构.结果表明,在较高的吸引强度和适当的浓度下,可以得到更多且更规整的蜂巢状结构;较高和较低的吸引强度和浓度都不利于金刚石状结构的形成. 相似文献
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First-principles calculations of equation of state and single-crystal elastic constants of copper are carried out up to twofold compression. The Helmholtz free energies are calculated using the quasi-harmonic phonon approach based on density-functional theory within both the local density approximation and the generalized gradient approximation (GGA). We find that the results calculated within GGA agree better with the experimental measurements in overall. The equation of state and the zero-pressure single-crystal elastic constants are close to the experimental values. 相似文献
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In situ energy dispersive x-ray diffraction for natural marmatite (Zn0.76Fe0.23S) is performed up to 17. 7 GPa and 623 K. It is fit, ted by the Birch-Murnaghan equation of state (EOS) that Ko and α0 for marmatite are 85(3)GPa and 0.79(16)*10^-4 K^-1, respectively. Fe^2+ isomorphic replacing to Zn^2+ in natural crystal is responsible for high bulk modulus and thermal expansivity of marmatite. Temperature derivative of bulk modulus (OK/OT)p for marmatite is fitted to be -0.044(23) GPaK^-1. The unambiguous B3-B1 phase boundaries for marmatite are determined to be Pupper(GPa)= 15.50 - 0.016T(℃) and Plower (GPa)=9.94-0.012T(℃) at 300-623K. 相似文献
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利用同步辐射x射线衍射和 DAC 高压技术在室温下测量了钙钛矿CaTiO3在压力0—44.53 GPa下的结构变化.结果表明,随着压力的增加CaTiO3的三个晶轴都受到不同程度的压缩,a,b的压缩率相近且相对比较大,c的压缩率最小,但没有证据表明有相变的发生.在压力范围内CaTiO3的P-V关系用Murnaghan状态方程表示,设定K′0=4,得到V0=0.2245(6)nm3和K0=222(9) GPa.应用赝立方角γpc与压力的关系,初
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3')" href="#">CaTiO3
结构
超高压
状态方程 相似文献