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31.
A series of Ba1-xSrxTi1-yZryO3 (0≤x≤0.5, 0≤y≤0.4) and BA1?xZnxTi1?ySnyO3 (0≤x≤0.3, 0≤y≤0.3) solid solutions were synthesized by low-temperature/low-pressure hydrothermal method below 170°C, 0.8
MPa. XRD pattern and cell parameters-composition figures of these prepared powders demonstrated that they are completely miscible
solid solutions based on BaTiO3. Furthermore, TEM showed that they have a shape of uniform, substantially spherical particles with an average particle size
of 70 nm in diameter. The sintered ceramics of those powders doped by Sr2+ and Zr4+ or Zn2+ and Sn4+ have dielectric constant twelve times higher than and dielectric loss 1/6 those of pure BaTiO3 phase at room temperature. 相似文献
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The study of millimeter-wave low sidelobe linear arrays with time modulation technique is presented in this paper. Special
emphasis is on the realization of low sidelobes with uniform amplitude excitations, which are easier for the practical implementation.
Two types of time modulated linear arrays with uniform amplitude excitations, namely, the variable aperture size (VAS) linear
arrays with optimized time sequences and the linear arrays with optimized random time sequences were studied. The optimized
time sequences are obtained via the differential evolution (DE) algorithm and the genetic algorithm (GA). Many factors that
affect the array performance are discussed.
Supported by the National Natural Science Foundation of China (No. 60571023), the SRF for ROCS, SEM, and the innovative Research
Team Program of UESTC, China. 相似文献
35.
Ce:Fe:LiNbO3 crystals with various [Li]/[Nb] ratios were grown by the Czochralski method from melts having compositions varying between 48.6 and 58 mol% Li2O. The Ce, Li and Nb concentrations in the grown Ce:Fe:LiNbO3 crystals were analyzed by the inductively coupled plasma atomic emission spectrometer (ICP-AES). It was found that as the [Li]/[Nb] ratio increases in the melt, the [Li]/[Nb] ratio in the crystal and the distribution coefficients of Ce ions increase also. The photorefractive properties of the Ce:Fe:LiNbO3 crystals were experimentally studied by the two-wave coupling method. The results show that as the [Li]/[Nb] ratio increases, the dynamic range decreases, but the photorefractive sensitivity and the signal-to-noise ratio improve. In a coherent volume 0.192 cm3 of a Ce:Fe:LiNbO3 crystal with [Li]/[Nb] ratio of 1.2, 3800 holograms with 800×600 pixels have been successfully multiplexed in a compact volume holographic data storage system. 相似文献
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Dr. Shiwen Wang Dr. Lijiang Wang Dr. Zhiqiang Zhu Zhe Hu Dr. Qing Zhao Prof. Dr. Jun Chen 《Angewandte Chemie (International ed. in English)》2014,53(23):5892-5896
Developing organic compounds with multifunctional groups to be used as electrode materials for rechargeable sodium‐ion batteries is very important. The organic tetrasodium salt of 2,5‐dihydroxyterephthalic acid (Na4DHTPA; Na4C8H2O6), which was prepared through a green one‐pot method, was investigated at potential windows of 1.6–2.8 V as the positive electrode or 0.1–1.8 V as the negative electrode (vs. Na+/Na), each delivering compatible and stable capacities of ca. 180 mAh g?1 with excellent cycling. A combination of electrochemical, spectroscopic and computational studies revealed that reversible uptake/removal of two Na+ ions is associated with the enolate groups at 1.6–2.8 V (Na2C8H2O6/Na4C8H2O6) and the carboxylate groups at 0.1–1.8 V (Na4C8H2O6/Na6C8H2O6). The use of Na4C8H2O6 as the initial active materials for both electrodes provided the first example of all‐organic rocking‐chair SIBs with an average operation voltage of 1.8 V and a practical energy density of about 65 Wh kg?1. 相似文献
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微管液相色谱法同时测定白术中的白术内酯Ⅲ、白术内酯I和苍术酮 总被引:1,自引:1,他引:0
采用微管液相色谱法同时测定白术中的白术内酯Ⅲ、白术内酯I和苍术酮.采用美国Micro-tech Ultra plusⅡTM微管柱通用型二元梯度高效液相色谱仪和Microsil C18微管色谱柱(150 mm×1.0 mm),以甲醇-乙腈-水(A相体积比为90:5:5;B相体积比为55:5:40)为流动相,梯度洗脱,流速50μL/mm,在220 nm波长下检测.在上述色谱条件下,3种组分分离良好,在相应的进样质量范围内具有良好的线性关系.白术内酯Ⅲ、I和苍术酮的加标回收率分别为96.86%,97.13%和98.06%;相对标准偏差分别为1.63%,1.31%和0.39%.该法简便、快捷,能够用于白术的质量控制. 相似文献
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Feixiang Cheng Shiwen Yu Pinhua Liu Mingli Ren Chixian He 《Journal of Coordination Chemistry》2016,69(23):3458-3471