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借处理2-羟基-5-(2-苯基-4-喹啉基)-1,3,二唑同PCl_5/POCl_3之间的反应合成了2-氯-5-(2-苯基-4-喹啉基)-1,3,4-二唑(3)和通过2-基-5-(2-苯基-4-喹啉基)-1,3,4-二唑的甲基化,然后氧化制得2-甲磺酰基-5-(2-苯基-4-喹啉基)-1,3,4-二唑(6).并分别研究了3和6同胺、叠氮及肼的反应,得到2,5-二取代的二唑新衍生物.初步观察了部分化合物的抗菌活性. 相似文献
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针对危险品车辆路径问题中车辆访问多个需求点的特性,在风险度量方式上考虑了运输过程中车辆载重量变化,建立了最小化总运输距离以及最小化总运输风险的双目标优化模型.采用改进的蚁群算法对模型进行求解并获得优化问题的非支配解,数值实验说明改进的风险度量方式更适合于危险化学品车辆路径问题,改进的蚁群算法能够有效率地对模型进行求解. 相似文献
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报道了双木脂素threo-(±)-开环异落叶松脂醇二阿魏酸酯的全合成.以香草醛为原料,经过两步Sto-bbe反应构建木脂素骨架,然后再用LiAlH4还原、加氢后,产物经柱层析分离,得到2个异构体meso-和threo-(±)-开环落叶松脂素;根据其NMR,IR和HRMS等谱图确认发现,极性较小的产物threo-(±)-开环落叶松脂素为合成的关键中间体.threo-(±)-开环落叶松脂素与甲氧甲基(MOM)保护的阿魏酸缩合得到目标产物threo-(±)-开环异落叶松脂醇二阿魏酸酯.合成采用汇聚法,经11步,以约8%的总产率得到了目标产物.该合成方法具有原料价廉易得及操作简便的优点,并具有一定的实用价值. 相似文献
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建立了新的Ad Hoc无线网络的区域划分和资源分配模型,讨论了网络覆盖率和抗毁性.通过构造Voronoi图对平面单连通区域的Ad Hoc网络建立区域划分优化模型;定义了网络抗毁性的评价指标连通率,并通过构造Delaunay三角网的最小生成树和蒙特卡罗实验,取得了较好的抗毁仿真结果.最后结合K-均值分簇和罚函数法,得到了近似最优的平面复连通区域的Ad Hoc网络的区域划分和信道安排. 相似文献
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Continuous CNT fibers have been directly fabricated in a speed of 50 m/h-400 m/h,based on an improved chemical vapor deposition method.As-prepared fibers are further post-treated by acid.According to the SEM images and Raman spectra,the acid treatment results in the compaction and surface modification of the CNTs in fibers,which are beneficial for the electron and load transfer.Compared to the HNO3 treatment,HClSO_3 or H_2SO_4 treatment is more effective for the improvement of the fibers' properties.After HCISO_3 treatment for 2 h,the fibers' strength and electrical conductivity reach up to-2 GPa and-4.3 MS/m,which are promoted by-200%and almost one order of magnitude than those without acid treatment,respectively.The load-bearing status of the CNT fibers are analyzed based on the downshifts of the G' band and the strain transfer factor of the fibers under tension.The results reveal that acid treatment could greatly enhance the load transfer and inter-bundle strength.With the HCISO3 treatment,the strain transfer factor is enhanced from-3.9%to-53.6%. 相似文献
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Detection of invisible phonon modes in individual defect-free carbon nanotubes by gradient-field Raman scattering 下载免费PDF全文
We provide an effective method to investigate the field gradient effect in nanoconfined plasmon-matter interaction.Aligned ultralong SWNTs without defects were grown on marked substrates, followed by assembling gold nanoparticle clusters around individual nanotubes. The Raman scattering behavior of a nanotube placed in an atomic scale nanogap between adjacent nanoparticles was studied. In addition to the expected plasmon-induced Raman enhancement up to 103,the defect-free D-mode of an individual SWNT induced by gradient field is found for the first time. When the light is confined at atomic scale, gradient field Raman scattering becomes significant and dipole-forbidden phonon modes can be activated by quadrupole Raman tensor variation, indicating breakdown of the Raman selection rules. 相似文献
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报道了双木脂素threo-(±)-开环异落叶松脂醇二阿魏酸酯的全合成. 以香草醛为原料, 经过两步Stobbe反应构建木脂素骨架, 然后再用LiAlH4还原、加氢后, 产物经柱层析分离, 得到2个异构体meso-和threo-(±)-开环落叶松脂素; 根据其NMR, IR和HRMS等谱图确认发现, 极性较小的产物threo-(±)-开环落叶松脂素为合成的关键中间体. threo-(±)-开环落叶松脂素与甲氧甲基(MOM)保护的阿魏酸缩合得到目标产物threo-(±)-开环异落叶松脂醇二阿魏酸酯. 合成采用汇聚法, 经11步, 以约8%的总产率得到了目标产物. 该合成方法具有原料价廉易得及操作简便的优点, 并具有一定的实用价值. 相似文献