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The Synthesis of a New Dumbbell-shaped Compound of Bis-4,4''''-bipyridine Bridged by 2,2''''-Bipyridine 总被引:1,自引:0,他引:1
Xin Hua XU* Rui Liang LU Bing ZHOU Jian Ping LI Yin Quan DENG College of Chemistry Chemical Engineering Hunan University Changsha The First Affiliated Hospital College of Medical Sciences Zhejiang University Hangzhou 《中国化学快报》2004,15(2)
Molecular machine is a new born research field1-5, Stoddart and co-workers firstly reported a molecular shuttles in 19916. In molecular machine a cyclic (bead) moves back and forth like a shuttles between two or more groups (station) having noncovalent interaction with a bead. Dumbbell-shaped component is the key intermediate for the synthesis of molecular machines7. One of the approaches for control movement of the bead is based on coordination reaction intrigue. In our protocol, a ligand… 相似文献
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Based on an orthogonal expansion in a triangle, superconvergence for L^2-projection to linear and quadratic triangular elements is studied.Assume that Ω is a polygonal domain,triangulation is uniform and Th is a set of all vertexesand side midpoints.Then, on Th,the average gradient ^-D(u-uh)=O(h^2) for linear element uh,and u-uh=O(h^4) for quadratic element uh. Under someboundary conditions,these properties upto the boundary are valid. 相似文献
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本文研究了马氏环境中的马氏链,利用马氏双链的性质,得到了马氏环境中的马氏链回返于小柱集上的概率的若干估计式. 相似文献
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基于比率的三种群捕食者-食饵扩散系统的周期解 总被引:15,自引:0,他引:15
本文研究一类基于比率的三种群捕食者-食饵扩散系统,利用重合度理论建立了这类系统正周期解的存在性结果。 相似文献
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5—Br—PNPFF与镍(Ⅱ)的显色反应及其分析应用 总被引:1,自引:0,他引:1
研究了新试剂1-(5’-溴-2’-吡啶基)-5-(4’-硝基苯基)-3-(2’-呋喃基)甲■(5-Br-PNPFF)与镍(Ⅲ)的显色反应条件。在吐温-80存在下,pH5.0的邻苯二甲酸氢钾-氢氧化钠缓冲介质中,镍(Ⅲ)与5-Br-PNPFF形成1:2的深绿色配合物,其最大吸收峰在7 10nm处,ε_(710)=4.89×10~4 L/mol.cm~(-1)。选择性好,镍含量在0~300μg/L范围内符合比尔定律。用所拟方法测定钢铁中的微量镍,结果满意。 相似文献
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建立了一种用于残留物分析样品处理的微量化学法(MICCM)体系,提出了该体系的基本概念、原理、单元操作,选择了一套基本系列设备和器具,并将这一体系用于检测不同样品中的农药、兽药、工业化学物残留量及食品添加剂。实例中,各方法检测限、回收率、变异系数的实验数据均达到了国际上对残留量分析方法的技术要求。该体系与经典常量化学法(MaCCM)样品处理体系相比,具有快速、简便、工效高,节省人力、试剂材料、能源以及占用场地小等多种优点。残留物分析可广泛用该体系取代经典法样品处理体系。 相似文献
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HuiYanLIU QingJiXIE 《中国化学快报》2004,15(5):563-566
Simultaneous impedance analysis of three one-face sealed resonating piezoelectric quartz crystals (PQCs) in parallel is proposed through admittance measurements of the three PQCs on one impedance analyzer and then non-linear fitting according to the parallel combination of three Butterworth-Van Dyke circuits. Responses of each PQC obtained from the three-PQC mode agreed well with those measured separately in series sucrose aqueous solutions. This novel method has been used for the study of depletion-layer effect during ferri-/ferrocyanide electrochemical reactions. 相似文献
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