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1.
R. W. Home 《Physics in Perspective (PIP)》2005,7(4):473-490
I survey highlights of the practice of physics and allied sciences in Melbourne,Australia, from the 1850s, soon after Europeans
first settled in the area, to the present. I note recognizable sites of past and current physical-science activity that may
be visited, as well as exhibits of historic items of physics apparatus. I trace the role of physics, in the course of a century
and a half, in the evolution of a pioneering settlement into a large city embedded in a modern industrial economy. 相似文献
2.
I.J. Galpin F.E. Hancock B.K. Handa A.G. Jackson G.W. Kenner P. McDowell P. Noble R. Ramage 《Tetrahedron》1981,37(17):3043-3050
The previously synthesised (1–37), (38–75), (76–93), (94–104), (105–117) and (118–129) fragments of the analogue were combined making extensive use of the DCCI/HONSu method. The final coupling involved the (1–75) and (76–129) sub-fragments. Aggregation of the latter fragment caused problems in purification by routine gel filtration methods employing Enzacryl K2 or Sephadex LH60. The fully protected (1–129) product was partially purified by washing, then deprotectcd and purified by gel filtration and ion exchange chromatography. Satisfactory removal of the acetamidomethyl group used for cysteine protection could not be achieved. 相似文献
3.
Fluorescence quantum yields and lifetimes of coumarin dyes are sharply reduced in polar solvents if amine substituent groups are free to rotate. The polar solvent effect is interpreted in terms of relaxation of excited dye from an initial planar conformation to a twisted zwitterionic state. 相似文献
4.
Berberine chloride (1) upon treatment with NaOAc-Ac2O yields naphthalene derivatives 4 and 5 In like fashion, 8 gives naphthalene 10; isoquinoline methiodide leads to β-naphthyl acetate; and 12 provides 14. The reaction has been extended to the 3-carbonyl pyridinium series where 3-acetylpyridine methiodide and 3-pyridinecarboxaldehyde methiodide furnish lactones 16 and 17, respectively. All these transformations proceed by initial nucleophilic attack of the acetic anhydride anion on the immonium carbon atom. 相似文献
5.
A rapid spectrophotometric method has been developed for the stepwise determination for mercury, cadmium, and zinc in mixtures. Optimal conditions have been established for the extraction efficiency of cadmium and mercury with a chloroform solution of tribenzylamine pre-equilibrated with hydrobromic acid. After addition of dithizone solution to the organic layers the absorbance at 490 nm or 510 nm is measured for mercury or cadmium, respectively. Even when the ratio of mercury, cadmium, and zinc is 10-1 : 1 : 10-5 , the metals can be determined successively. 相似文献
6.
Scott Gaynor Dorota Greszta Daniela Mardare Mircea Teodorescu Krzysztof Matyjaszewski 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(11):1561-1578
Various methods which lead to the control of molecular weight and polydispersities, and which allow for the preparation of block copolymers by radical polymerization are discussed. Thermal polymerizationof styrenes in the presence of stable radicals, polymerization of vinyl acetate and methyl methacrylate in the presence of chromium complexed by macrocyclic ligands polymerization of vinyl acetate initiated by organoaluminum compounds complexed by dipyridyl and activated by stable radicals, as well as in the presence of phosphites, are described in detail. 相似文献
7.
8.
基于G/S模式的空间信息云服务架构研究 总被引:1,自引:0,他引:1
针对多系统间的数据交换、共享问题,尤其在大数据时代,海量的数据增长给数据的管理带来的挑战,提出了一种基于G/S(General-Browser/ Service-Cloud,G/S)模式的空间信息云服务架构——面向数据的架构(Data Oriented Architecture,DOA)。以数据为核心,以数据标识为主线,通过数据注册中心和数据交换规范XXML(Specific Industry Markup Language),对海量异构数据进行存储、计算和管理,实现多系统间的数据共享、访问和协同。通过在地质灾害监测预警方面的应用,证明了该架构作为信息技术的系统构建方法在大数据时代独特的优势。 相似文献
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10.