地物介电常数测量和分析

详细分析了基于矢量风络分析仪的同轴线探头介电常数测量系统和地物介电常数的测量方法。给出了几种典型地物（沙子、岩石、树木、棉叶）介电常数的测量和分析结果，并在模型进行了比较。本文实测数据可用于地物散射和辐射特性研究。     

Hard Macrocellular Silica Si(HIPE) Foams Templating Micro/Macroporous Carbonaceous Monoliths: Applications as Lithium Ion Battery Negative Electrodes and Electrochemical Capacitors

By using Si(HIPEs) as hard, exotemplating matrices, interconnected macro‐/microporous carbon monolith‐type materials with a surface area of around 600 m² g^?1 are synthesized and shaped. The carbonaceous foams exhibit a conductivity of 20 S cm^?1, addressed with excellent mechanical properties (Young's modulus of 0.2 GPa and toughness of 13 J g^?1, when the carbon core is optimized). The above‐mentioned specificities, combined with the fact that the external shape and size can be easily designed on demand, are of primary importance for applications. The functionality of these carbonaceous monoliths is tested as both an electrochemical capacitor and a lithium ion negative electrode. The electrochemical capacitors' voltage–current profiles exhibit a non‐ideal rectangular response, confirming the double‐layer behavior of the carbon studied, while the charge‐discharge current profile of the electric double‐layer capacitor is directly proportional to the scan where the current response during charge and discharge exhibits high reversibility. When acting as a lithium ion negative electrode, after initial irreversibility, a good cyclability is obtained, associated with a stable capacity of 200 mA h g^?1 during the first 50 cycles at a reasonable current density (C/10).     

The dielectric constant of materials effect the property of the OLED

Several important materials have been used for the electron injection layer (EIL) of the organic light-emitting devices (OLEDs), such as LiF, NaCl, NaF, Al₂O₃, SiO₂, Si₃N₄, MgO, etc. LiF is the most usually used in OLED among these materials for its performance in OLED. The dielectric constant of LiF, NaCl, NaF is 9.036, 5.895 and 5.072, respectively, at 300 K [J. Fontanella, C. Andeen, D. Schuele, Phys. Rev. B 6 (1972) 582]. The thin film of these insulting layers here supply a very strong electric field to enhance the electrons injection and limit the holes injection to the emitting layer (EL). Then we kept the balance of the injected electrons and the holes, and then we got the excellent performing OLEDs.     

Microscopic properties of H2 diluted HWCVD deposited a-SiC:H film

Hydrogenated amorphous silicon carbon (a-SiC:H) films were deposited by hot wire chemical vapor deposition. The evolution of microscopic properties like network bonding, disorder, density and chemical composition are studied as a function of H₂ dilution. The sp² and sp³ carbon clusters, hydrogen content and the density of the material has significant effect on the dielectric properties like the leakage current of M/a-SiC:H/〈Si〉 MIS structures made with both Cu and Al metal electrode. A higher leakage current is observed in the case of Cu electrode. These changes are important for its applicability as a low dielectric constant barrier material in microelectronic devices.