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以立方焦绿石Bi1.5Zn1.0Nb1.5O7(BZN)为配方基础,通过掺入过量10%的Bi2O3,形成Bi1.65Zn1.0Nb1.5O7.225非化学计量比分子式.采用固相反应法合成具有焦绿石立方结构的Bi1.65Zn1.0Nb1.5O7.225陶瓷,并采用脉冲激光沉积法在Pt/SiO2/Si(100)基片上制备其薄膜.对比研究了非化学计量比Bi1.5Zn1.0Nb1.5O7.225陶瓷和薄膜的结晶性能,微观形貌以及介电性能的差异.结果表明烧结的Bi1.65Zn1.0Nb1.5O7.225陶瓷和沉积的BZN薄膜都保持立方焦绿石单相结构,但是薄膜展现出较强的(222)晶面择优取向.陶瓷和薄膜的晶格常数,微观形貌都体现出差异.对比二者的介电特性后发现,Bi1.65Zn1.0Nb1.5O7.225薄膜的介电常数明显高于陶瓷的介电常数,这归因于薄膜和块体材料之间的差异,例如厚度,致密度,择优取向等. 相似文献
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本文引进了C#-单调范数的概念.利用这个概念,我们给出了Henig有效点的切比雪夫标量化结果. 相似文献
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以双氧水为氧化剂,甲酸为氧载体,用强酸性阳离子交换树脂作催化剂,结合正交实验和单因素实验,确定红花籽油环氧化反应的最佳工艺条件为:在少量金属掩蔽剂乙二胺四乙酸二钠(EDTA)存在下,红花籽油、88%甲酸、30%双氧水和阳离子交换树脂的质量比为1∶0.244∶1.665∶0.035,在60 ℃下反应6 h,搅拌速度400 r/min,产品的环氧值可达到7以上。 相似文献
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A novel structure is proposed for doubling the vertical breakdown voltage of silicon-on-insulator(SOI) devices. In this new structure, the conventional buried oxide(BOX) in an SOI device is split into two sections: the source-section BOX and the drain-section BOX. A highly-doped Si layer, referred to as a non-depletion potential-clamped layer(NPCL), is positioned under and close to the two BOX sections. In the split BOXes and the Si region above the BOXes, the blocking voltage(BV) is divided into two parts by the NPCL. The voltage in the NPCL is clamped to be nearly half of the drain voltage. When the drain voltage approaches a breakdown value, the voltage sustained by the source-section BOX and the Si region under the source are nearly the same as the voltage sustained by the drain-section BOX and the Si region under the drain. The vertical BV is therefore almost doubled. The effectiveness of this new structure was verified for a P-channel SOI lateral double-diffused metal-oxide semiconductor(LDMOS) and can be applied to other high-voltage SOI devices. The simulation results show that the BV in an NPCL P-channel SOI LDMOS is improved by 55% and the specific on-resistance(Ron,sp) is reduced by 69% in comparison to the conventional structure. 相似文献
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正如前文报道,l,3,4—噻二唑类杂环之所以有除草,植物生长调节,驱虫以及消炎等多种生物活性,无疑起因于噻唑母核。尽管母核上取代基不起主导作用,但它作为辅助基,在改善分子溶解性以及药效方面所产生的影响是不能忽略的。因而深入研究各种生物活性基团导入噻二唑环母核以制得多结构单元聚集于同一分子中的噻二唑新衍生物,对于开发多功能新药具有一定的理论意义和实际价值。 相似文献