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Anguo Ying Ming Zheng Haidan Xu Fangli Qiu Changhua Ge 《Research on Chemical Intermediates》2011,37(8):883-890
An efficient and facile protocol for aza-Michael addition of aliphatic and aromatic amines to electron-deficit alkenes using
[TMG][Lac] as catalyst under solvent-free conditions was established. 相似文献
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Wireless Personal Communications - In this paper, we investigate the secrecy outage performance of the decode-and-forward cognitive relay network with the existence of the co-channel interference,... 相似文献
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采用新的方法推导出非均匀介质中对称耦合三线的传输矩阵 ( T参数 )解析表达式 ,给出了以正规模式参量描述的 T参数表达式。所得 T参数表达式形式简明 ,物理概念明晰。将无损状态下的 T参数通过矩阵分块运算推导 S参数 ,与文献结果进行了验证。验证结果表明所得 T参数解析表达式的正确性和本文方法的有效性。非均匀介质中对称耦合三线的 T参数解析表达式的导出为其在微波集成电路及三维 (多层 )微波集成电路中的应用提供了有力的理论工具。 相似文献
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周期性缺陷接地结构的BP神经网络模型 总被引:2,自引:1,他引:2
缺陷接地结构 (DGS)是由光子带隙结构 (PBG)发展而来的 ,它是在微波电路的接地金属平面上人为地蚀刻出“缺陷”,改变接地电流的分布 ,从而改变传输线的频率特性。周期性缺陷接地结构 (PDGS)是一种在微波电路的接地金属平面上人为地蚀刻出周期性的“缺陷”结构 ,能够使某些频段的电磁波无法从中通过 ,存在明显的阻带特性。文中采用人工神经网络对周期性缺陷接地结构进行建模 ,将其结构尺寸和频率作为输入样本 ,传输系数参数作为输出样本 ,采用贝叶斯正则化算法对神经网络进行训练。神经网络训练完成后 ,在学习范围内将其结构尺寸和频率输入到神经网络模型 ,从输出端立即得到准确的传输系数。 相似文献
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XU Songlin XIANG Aishuang & YING Anguo National Engineering Research Center for Distillation Technology School of Chemical Engineering Tianjin University Tianjin China 《中国科学B辑(英文版)》2004,47(6):521-527
3-hydroxypropionitrile (HPN) is widely used asmaterials in many organic reactions such as synthe-sizing medicine, pesticide and polymeric compound.Since the 1970s, HPN has mostly been synthesizedwith the reaction of acrylonitrile and H2O catalyzed byNaOH aqueous solution, and the mole yield of HPN isabove 85%. However, the HPN must be separatedfrom the acrylonitrile hydration mixture and get rid ofwater, salt and other side products. The traditional separation method is evapora-tion… 相似文献
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Using a novel approach, the analytic expressions of the ABCD parameters for the symmetric coupled three-line in an inhomogeneous medium (SCTLIM) are derived in this paper for the first time. The expressions of the ABCD parameters for the SCTLIM are given in forms of the normal mode parameters. These expressions are explicit in expression and clear in conception. Using the matrix operation, the presented expressions have been verified by results derived from the Z-matrix. It is also shown that the novel method presented in the paper is very effective. The ABCD parameters given in the paper will provide a powerful theoretical tool for the application of the SCTLIM in microwave integrated circuits and three-dimensional (multilayer) microwave integrated circuits. 相似文献