3 research outputs found

    Flexible decapyrrylcorannulene hosts

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    球形笼状的富勒烯是上个世纪末最重要的科学发现之一,但对富勒烯的精确几何结构的认识却困难重重,原因是单晶中球形分子的取向往往是无序的,需通过笼外衍生或通过八乙基金属卟啉-富勒烯超分子主客体组装来固定富勒烯的取向,然后利用常用的单晶衍射分析技术来精确表征富勒烯的几何结构。然而许多富勒烯新结构因无法与卟啉主体形成高质量的单晶至今仍无法利用X射线衍射技术进行结构分析,直接制约了对富勒烯形成机理及结构-性能关系的深入认识。功能团簇材料创新研究群体的谢素原、张前炎课题组另辟蹊径地从曲面结构的十氯碗烯C20Cl10出发,合成了十吡咯取代的碗烯分子C20(C4H4N)10。结构分析表明该分子的结构特征是碗烯的碳框架与十个吡咯基团通过单键相连。实验还证明,用甲基去取代吡咯3, 4-位置的氢并不利于富勒烯与碗烯衍生物形成有序的超分子组装体,理论研究进一步诠释了十个吡咯‘手指’的集体贡献比单个碗烯‘手掌’更大的原因。该研究工作是功能团簇材料创新研究群体长期积累,并由校内外十多位研究人员共同努力完成。徐云彦(2014级硕士生)、田寒蕊(2014级博士生)和李姝慧(2016年进站博士后)为该论文共同第一作者。【Abstract】The assembly of spherical fullerenes, or buckyballs, into single crystals for crystallographic identification often suffers from disordered arrangement. Here we show a chiral configuration of decapyrrylcorannulene that has a concave ‘palm’ of corannulene and ten flexible electron-rich pyrryl group ‘fingers’ to mimic the smart molecular ‘hands’ for self-adaptably cradling various buckyballs in a (+)hand-ball-hand(−) mode. As exemplified by crystallographic identification of 15 buckyball structures representing pristine, exohedral, endohedral, dimeric and hetero-derivatization, the pyrryl groups twist with varying dihedral angles to adjust the interaction between decapyrrylcorannulene and fullerene. The self-adaptable electron-rich pyrryl groups, susceptible to methylation, are theoretically revealed to contribute more than the bowl-shaped palm of the corannulene in holding buckyball structures. The generality of the present decapyrrylcorannulene host with flexible pyrryl groups facilitates the visualization of numerous unknown/unsolved fullerenes by crystallography and the assembly of the otherwise close-packed spherical fullerenes into two-dimensional layered structures by intercalation.This research was supported by the National Natural Science Foundation of China (21771152, 21721001, 21827801, 51572231, 51572254, 21571151, 2170010228), the 973 Program of China (2014CB845601 and 2015CB932301), the China Postdoctoral Science Foundation (2016M602067), the National Key Research and Development Program of China (2017YFA0402800), and the Fundamental Research Funds for the Central Uni- versities (20720170028, 20720160084). Q.Y.Z. is particularly grateful to 21771152, 2015CB932301, 20720170028, 20720160084; S.F.Y. is particularly grateful to 51572254 and 2017YFA0402800; S.Y.X. is particularly grateful to 21721001 and 51572231; L.S.Z. is particularly grateful to 21827801; S.L.D. is particularly grateful to 21571151; S.H.L. is particularly grateful to 2170010228 and 2016M602067. 研究工作得到国家自然科学基金(21771152、21721001、21827801、51572231、51572254, 21571151、2170010228)、科技部973计划(2014CB845601、2015CB932301)和重点研发计划(2017YFA0402800)、国家博士后科学基金、中央高校基本科研业务费等的资助

    楔形体结构入水的SPH数值模拟研究

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    结构入水问题在民用和军事等方面有广泛的应用,是一个热点研究领域。而结构入水涉及自由液面的运动、翻卷和破碎,强烈的流固耦合作用,以及复杂的湍流现象,也一直是水动力学领域的一个难点问题。光滑粒子动力学(SPH)方法作为一种无网格粒子方法,兼具欧拉法和拉格朗日法的优点,能够自然追踪运动界面,方便处理大变形和流固耦合问题,在模拟结构入水等强非线性水动力学问题方面有独特的优势。但是传统SPH方法往往计算精度较低,可能出现数值不稳定,边界处精度难以保证,并缺乏有效的流固耦合模型等问题。本文深入分析了SPH方法在入水问题中涉及的边界处理、流固耦合和湍流现象,提出和应用了有效的数值模型,并在此基础上应用SPH方法对不同角度、速度的楔形体入水问题的液面变化、压强分布和速度分布进行了研究和分析

    一种用于测试光学探测器的地球模拟装置

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    本发明涉及一种用于测试光学探测器的地球模拟装置。该装置的特征在于在一个地球模型壳体中放置光源模拟地球,地球模型壳体始终有半个球可透光,并通过多维运动组合平台联接驱动,从而实现模拟在不同地球轨道上观测地球的功能;利用本发明可以广泛应用于模拟各种用以在卫星和航天器上的光学探测器观测地球以验证光学探测器性能的工作中
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