This paper presents a passive wireless polymer-derived silicon carbonitride (SiCN) ceramic sensor based on cavity radio frequency resonator together with integrated slot antenna. The effect of the cavity sensor dimensions on the Q-factor and resonant frequency is investigated by numerical simulation. A sensor with optimal dimensions is designed and fabricated. It is demonstrated that the sensor signal can be wirelessly detected at distances up to 20 mm. Given the high-temperature stability of the SiCN, the sensor is very promising for high-temperature wireless sensing applications. V

Shale oil and gas have been discovered in the lacustrine organicrich Zhangjiatan Shale of the Upper Triassic Yanchang Formation, Ordos Basin, China. Core observations indicate abundant silty laminae in the producing shales. This study documents the stratigraphic distribution of silty laminae and their relationship with interlaminated clay laminae. The type, structure, and characteristics of pores and mineral composition of silty laminae were observed and analyzed through thin section and scanning electron microscopy, X-ray diffraction, low-pressure CO 2 and N 2 adsorption, mercury porosimetry, and helium pycnometry. Results from silty laminae are compared with those of clayey laminae. The frequency and thickness of silty laminae vary over a wide range. The thickness ranges from 0.2 to 4 mm and is 1.5 mm on average; the frequency ranges from 4 to 32 laminae/m and is 23 laminae/m on average. The thickness percentage of silty laminae in the measured segments ranges from 6% to 17%. Silty laminae consist of quartz, feldspar, mixed-layer montmorillonite, and chlorite. In comparison to clayey laminae, non-clay detrital grains are larger, quartz and feldspar are more common, and clay minerals are less abundant. Pores in silty laminae are primary interparticle, dissolutional, intercrystalline, and microfracture types. Mesopores (2-50 nm in diameter) and macropores (50 nm-1 μm) are common, whereas, micropores ð<2 nmÞ are rare; the distribution of pore diameters is multimodal. However, microscopic pores with a diameter commonly smaller than 100 nm are common in

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Large discharge energy density and high energy efficiency are obtained simultaneously in antiferroelectric PLZST/P(VDF-HFP) polymer nanocomposites.

We report the synthesis of silicon oxycarbonitride ceramic‐graphene oxide (SiCNO–GO) composites by using polyvinylsilazne (PVSZ) and GO as precursors through cross‐linking processes, in which GO organizes into microspheres in the SiCNO matrix. The formation of GO microspheres significantly enhances the electrical conductivity of SiCNO. The electrical resistivity of SiCNO–GO composites shows a negative temperature coefficient in the range from 25°C to 600°C. We demonstrate the application of SiCNO–GO composites as the functional component of high‐temperature sensors.

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Silicon carbide (SiC) fibers are prepared using an iron-containing polycarbosilane (Fe-PCS) as the precursor. Iron pentacarbonyl [Fe(CO) 5 ] is first reacted with low-molecular-weight liquid PCS to form an iron-containing colloid. The colloid is then added into high-molecular-weight solid PCS to form Fe-PCS. Formation of the iron-containing colloid as well as the SiC fiber processing has been studied. It is found that during the preparation of the colloid, the iron pentacarbonyl first decomposes under heat into nanosized carbonyl derivatives and CO. CO then reacts with liquid PCS at the interface, rendering liquid PCS cross-linked and hence the particles encapsulated. At a higher temperature, the derivatives further decompose into nanosized iron particles. The iron exists as nanosized a-Fe domains (B5 nm) and is highly uniformly distributed inside the ceramic fibers. Ceramic fibers containing 3.64 wt% iron have a good combination of tensile strength (2.37 GPa), electrical resistivity (0.46 X . m) and magnetic properties (a saturation magnetization of 1.48 A . m 2 /kg and a coercivity of 5094 A/m).