Anion Resistant Oxygen Reduction Electrocatalyst in Phosphoric Acid Fuel Cell
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99 GENERAL AND MISCELLANEOUS↗
Engineering topics
Liang, W.
Publications and source records attributed to Liang, W..
Carbon isotopic signatures of super-deep diamonds mediated by iron redox chemistry
Among redox sensitive elements, carbon is specifically important because it may have been a driver rather than a passive recorder of Earth’s redox evolution. The extent to which the isotopic composition of carbon records the redox processes that shaped the Earth is still debated. In particular, the highly reduced deep mantle may be metal-saturated, yet, it is still unclear how the presence of metallic phases influences the carbon isotopic compositions of super-deep diamonds. Here we report ab initio results for the vibrational properties of carbon in carbonates, diamond, and Fe 3 C under pressure and temperature conditions relevant to super-deep diamond formation. Previous work on this question neglected the effect of pressure on the equilibrium carbon isotopic fractionation between diamond and Fe 3 C but our calculations show that this assumption overestimates the fractionation by a factor of ~1.3. Our calculated probability density functions for the carbon isotopic compositions of super-deep diamonds derived from metallic melt can readily explain the very light carbon isotopic compositions observed in some super-deep diamonds. Our results therefore support the view that metallic phases are present during the formation of super-deep diamonds in the mantle below ~250 km.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Photonic E-field sensor
We report on both theoretical and experimental studies of a photonic implementation of the electric (E-) field sensor using a probe made with all-dielectric RF-transparent elements. The geometrical dimensions of the electric field probe can be smaller than the wavelength of the measured electromagnetic field in the material. Our theoretical calculations show that the sensor allows detecting electric fields in a broad frequency range (100 Hz-20 GHz) with sensitivity better than 1 μV/[Hz{sup 1/2} m]. We demonstrate the sensor operating at X-band and validate the theoretical predictions.
36 MATERIALS SCIENCE↗