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选择适当的反应条件实现对环境无害的有机及催化反应是 2 1世纪化学家所面临的重要挑战 [1~ 3 ] .Kuntz研究组 1 975年开展民含水两相催化反应的研究 [4 ] ,水溶性膦配体与过渡金属 (如铑、钯和镍等 )所形成的配合物可在水 /有机两相催化体系中实现不对称氢化、烯丙型烷基化、 相似文献
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The crystal structure of the title compound C15H16NO2+ · I-(Mr=369. 19) has been determined by single crystal X-ray diffraction analysis. The crystal belongs to tbe monoclinic system with space group P21/c, a=8. 957(1), b=21. 8117(2), c=7. 8760(10)A , β=103.94(1)°, V=1493.8(3)A3, Z=4, Dc=1. 642g cm3,μ=2. 141mm-1, F(000)=728, final R=0. 0264, and Rw=0. 0644(I>2σ(I)) for 2938 independent reflections. The results show that in the crystal structure of the title compound the planar cations have two configurations, and these cations are anti-parallelly packed through the strong π…π interaction. 相似文献
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1 INTRODUCTIONAs a useful nonlinear optical material, the molecule must have a large second-order hyperpolarizability (β), and also must crystallize in a non-centrosymmetric structure to have a large ((2). Organic conjugated molecules with electronic donors and acceptors possibly have quite strong second-order NLO property. However, only a small percentage of the molecules with large β crystal-lize in useful non-centrosymmetric crystals. Marder and his co-worker carried out a simple an… 相似文献
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超导纳米线单光子探测器(SNSPD)因其优异的综合性能,在量子信息、激光雷达等方面有广泛的应用.通常, SNSPD工作在直流偏置下,在时域上具有自由运行探测的优点.而在卫星激光测距、单光子激光雷达等光信号到达时间有规律的应用场景中,使用交流偏置有望提升器件运行速率、有效抑制背景暗计数,却存在信号读出困难的棘手问题.本文报道了自差分读出的交流偏置SNSPD系统,该系统包含两根并行排布纳米线构成的2-pixel SNSPD器件.给两根纳米线加载相同的100 MHz交流偏置信号,并对两路输出信号差分使噪声信号相抵消,实现光子响应信号的读出.基于该方法测得,响应信号的信噪比相比差分之前提升10倍,在交流偏置下器件的暗计数降低至直流偏置下的约1/4,计数率达到直流偏置下的约1.5倍.本文为交流偏置SNSPD测试提供了一种思路,为其应用提供参考数据. 相似文献
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