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11.
Keri T. Horne Gregory L. Powell Lee M. Daniels 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(5):m302-m303
The title complex [systematic name: pentachloro‐1κ3Cl,2κ2Cl‐tris(diethylphenylphosphino)‐1κP,2κ2P‐dirhenium(II,III)(Re—Re)], 1,3,6‐Re2Cl5(PEt2Ph)3 or [Re2Cl5(C10H15P)3], consists of dirhenium molecules with eclipsed structures similar to those of previously characterized 1,3,6‐Re2Cl5(PR3)3 compounds. The Re—Re bond distance is 2.2262 (3) Å and the metal–metal bond order is 3.5. 相似文献
12.
Japheth F. Rauscher Cathie L. Condron Tanya Beault Susan M. Kauzlarich Newell Jensen Peter Klavins Samuel MaQuilon Zachary Fisk Marilyn M. Olmstead 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(10):i69-i73
Single crystals of the new Zintl phases AIn2P2 [A = Ca (calcium indium phosphide), Sr (strontium indium phosphide) and Ba (barium indium phosphide)] have been synthesized from a reactive indium flux. CaIn2P2 and SrIn2P2 are isostructural with EuIn2P2 and crystallize in the space group P63/mmc. The alkaline earth cations A are located at a site with m symmetry; In and P are located at sites with 3m symmetry. The structure type consists of layers of A2+ cations separated by [In2P2]2− anions that contain [In2P6] eclipsed ethane‐like units that are further connected by shared P atoms. This yields a double layer of six‐membered rings in which the In—In bonds are parallel to the c axis and to one another. BaIn2P2 crystallizes in a new structure type in the space group P21/m with Z = 4, with all atoms residing on sites of mirror symmetry. The structure contains layers of Ba2+ cations separated by [In2P2]2− layers of staggered [In2P6] units that form a mixture of four‐, five‐ and six‐membered rings. As a consequence of this more complicated layered structure, both the steric and electronic requirements of the large Ba2+ cation are met. 相似文献
13.
A resonance phenomenon which can occur in elastic systems supporting wave motion is discussed. An analytical and numerical study of the dynamic stability of a cylindrical shell under axial compression illustrates the potential importance of this resonance phenomenon for imperfection-sensitive structures. 相似文献
14.
T. Shimmura H. Nomura H. Hock E. Fritz E. S. Grumell J. G. King E. G. Bailey F. Heathcoat W. Franke F. Eck I. A. Davies R. Vondráček D. Florentin C. Holthaus W. A. Selvig W. D. Pohle G. Speckhardt A. R. Powell C. C. Russell E. L. Skau I. L. Newell F. H. Gibson 《Analytical and bioanalytical chemistry》1934,99(3-4):148-153
15.
J. B. Ficklen I. L. Newell und N. R. Pike 《Fresenius' Journal of Analytical Chemistry》1936,104(1-2):30-34
Zusammenfassung In Anbetracht dieser Ergebnisse kann Cinchoninjodid nicht als spezifisches Reagens auf Wismut angeseben werden; es wird sich kaum zur Bestimmung von Wismut bei Gegenwart unbekannter Substanzen eignen.Wegen seiner Empfindlichkeit (4,9.10–6m oder ungefahr 1:1000000) könnte es sich wohl für eine schnelle, einwandfreie Bestimmung als brauchbar erweisen, doch muß das Wismut vorber nach einer Standardmethode isoliert werden. 相似文献
16.
Ytterbium-doped fiber lasers are making impressive leaps in power production. Yet in spite of fiber’s large surface area to volume ratio which is beneficial for cooling, such power inevitably leads to high core temperatures that in turn affect the laser performance. In this paper, the temperature effects on the emission and fluorescence lifetime of ytterbium-doped optical fibers are investigated. From these the temperature dependent emission and absorption cross-sections are calculated. 相似文献
17.
The universality of many features of plant patterns and phyllotaxis has mystified and intrigued natural scientists for at
least four hundred years. It is remarkable that, to date, there is no widely accepted theory to explain the observations.
We hope that the ideas explained below lead towards increased understanding 相似文献
18.
Alfonso Gill Azpeitia Gordon Frank Newell 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1959,10(1):15-34
The viscous drag exerted by a fluid on an oscillating disk is determined by methods similar to those used in Part III. The present paper differs from Part III in that the boundary layer thickness is assumed here to be small compared with both the thickness and the radius of the disk. An extrapolation of the formulae derived here agree sufficiently well, however, with those derived for the thin disk (boundary layer thickness large compared with the thickness but small compared with the radius) that it is possible to make an interpolation between the present formulae and those of Part III that will permit the evaluation of the drag for arbitrary shape disks provided the boundary layer thickness is small compared with the radius.
This research was supported by the United States Air Force through the Air Force Office of Scientific Research of the Air Research and Development Command, under contract No. AF 18 (600) 1548. Reproduction in whole or in part is permitted for any purpose of the United States Government. Part of the work was done while one of the authors (G. F. N.) was being supported by a grant from the Alfred P. Sloan Foundation. 相似文献
Zusammenfassung Der Einfluss der Zähigkeitskräfte auf eine in einer Flüssigkeit schwingende Scheibe wird nach den gleichen Methoden wie in Tiel III behandelt. Jedoch wird im Unterschied dazu vorausgesetzt, dass die Grenzschichtdicke klein ist im Verhältnis zur Dicke und zum Radius der Scheibe. Die abgeleiteten Formeln lassen sich mit gutem Ergebnis für die dünne Scheibe extrapolieren (hier ist die Grenzschichtdicke jedoch gross, verglichen mit der Scheibendicke, aber klein gegenüber dem Radius), so dass es möglich ist, zwischen diesen Formeln und denen des Teils III zu interpolieren. Damit wird die Berechnung des Reibungsmomentes für Scheiben unterschiedlichster Form ermöglicht, vorausgesetzt, dass die Grenzschichtdicke klein ist gegenüber dem Radius der Scheibe.
This research was supported by the United States Air Force through the Air Force Office of Scientific Research of the Air Research and Development Command, under contract No. AF 18 (600) 1548. Reproduction in whole or in part is permitted for any purpose of the United States Government. Part of the work was done while one of the authors (G. F. N.) was being supported by a grant from the Alfred P. Sloan Foundation. 相似文献
19.
20.
Mark J. Ablowitz David J. Kaup Alan C. Newell Harvey Segur 《Studies in Applied Mathematics》1974,53(4):249-315
A systematic method is developed which allows one to identify certain important classes of evolution equations which can be solved by the method of inverse scattering. The form of each evolution equation is characterized by the dispersion relation of its associated linearized version and an integro-differential operator. A comprehensive presentation of the inverse scattering method is given and general features of the solution are discussed. The relationship of the scattering theory and Backlund transformations is brought out. In view of the role of the dispersion relation, the comparatively simple asymptotic states, and the similarity of the method itself to Fourier transforms, this theory can be considered a natural extension of Fourier analysis to nonlinear problems. 相似文献