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21.
Neil Bartlett Sam Yeh Kostantinos Kourtakis Tom Mallouk 《Journal of fluorine chemistry》1984,26(1):97-116
Iridium hexafluoride oxidizes ReF6 (via an ReF6+ salt) and at room temperatures IrF6, ReF6, ReF7 and (IrF5)4 are each present in the equilibrium mixture. From these and related findings: ΔH°(ReF6 → ReF6+ + e?) 1092 ± 27 kj mole?1(261 ± 6 kcal mole?1), and thermodynamic data are selected to yield ΔH°(ReF7(g) → ReF6+(g) + F?(g))=893 ± 33 kj mole?1(213 ± 8 kcal mole?1). From observations on the stability of IF6+BF4? and the lattice enthalpy evaluation for the salt, ΔH°(IF7(g) → IF6+(g) + F?(g))= 870 ± 24 kj mole?1(208 ± 6 kcal mole?1). 相似文献
22.
In this letter we describe the advantages of a dynamic optical interconnection system for parallel information processing applications. The system is based on a liquid crystal television which acts as a binary phase-only spatial light modulator. We describe example algorithms where reconfigurable interconnects would be useful and present results of several interconnection topologies which have been implemented.Presented at the International Commission for Optics Topical Meeting, Kyoto, 1994. 相似文献
23.
Serum proteins represent an important class of drug and imaging agent delivery vectors. In this minireview, key advantages of using serum proteins are discussed, followed by the particular advantages and challenges associated with employing soluble folate binding protein. In particular, approaches employing drugs that target folate metabolism are reviewed. Additionally, the slow-onset, tightbinding interaction of folate with folate binding protein and the relationship to a natural oligomerization mechanism is discussed. These unique aspects of folate binding protein suggest interesting applications for the protein as a vector for further drug and imaging agent development. 相似文献
24.
Kaiming Zhou David Webb Mark Farries Neil Hayes Lin Zhang Ian Bennion 《Optics and Lasers in Engineering》2009,47(10):1023-1027
A novel all-fibre cavity ring down spectroscopy technique is proposed where a tilt fibre Bragg grating (TFBG) or long-period grating (LPG) in the cavity provides sensitivity to surrounding medium. Such configuration with an LPG as the representative was theoretically analyzed. Two spectral bands were identified employable for sensing of surrounding refractive index for a weak LPG while only one band existed for a strong LPG. A TFBG, with enhanced sensitivity compared to usual LPGs, was used in a ring down cavity of 1 m constructed with 2 fibre Bragg gratings as the reflectors and the decay time changed from 220 to 450 ns when the TFBG was immersed into water from air. 相似文献
25.
Harry Adams Neil A. Bailey David E. Fenton Choki Fukuhara Masatoshi Kanesato 《Supramolecular chemistry》2013,25(4):325-330
Abstract The synthesis and crystal structure of the diprotonated cryptand derived from the reaction of tren and 2,6-diacetyl pyridine is reported. The imino nitrogens of the Schiff base linkages are directed so that the dicarbimine functions are in trans, trans geometry relative to the pyridine C-N bond. This configuration has not previously been reported in related pyridine-derived Schiff base macrocycles. 相似文献
26.
A transitive triple, (a,b,c), is defined to be the set {(a,b), (b,c), (a,c)} of ordered pairs. A directed triple system of order v, DTS(v), is a pair (D,β), where D is a set of v points and β is a collection of transitive triples of pairwise distinct points of D such that any ordered pair of distinct points of D is contained in precisely one transitive triple of β. An antiautomorphism of a Directed triple system, (D,β), is a permutation of D that maps β to β−1, where β −1 = {(c,b,a)|(a,b,c) E β}. In this article we give necessary and sufficient conditions for the existence of a Directed triple system of order v admitting an antiautomorphism consisting of a single cycle of length d and having v − d fixed points. Further, we give a more general result for partial Directed triple systems in which the missing ordered pairs are precisely those containing two fixed points. © 1996 John Wiley & Sons, Inc. 相似文献
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We have observed phase defects in quasi-2D Bose-Einstein condensates close to the condensation temperature. Either a single or several equally spaced condensates are produced by selectively evaporating the sites of a 1D optical lattice. When several clouds are released from the lattice and allowed to overlap, dislocation lines in the interference patterns reveal nontrivial phase defects. 相似文献
29.
Michael Bowker Richard Holroyd Neil Perkins Jenita Bhantoo Albert Carley 《Surface science》2007,601(17):3651-3660
The reaction of acetaldehyde with the Pd(1 1 0) surface has been studied using a molecular beam reactor, TPD and LEED. Below 270 K acetaldehyde sticks to the surface with a high initial probability (∼0.8), but no gas phase products evolve. When the reaction is run at >270 K, hydrogen evolves into the gas phase early in the reaction together with methane in a non-steady-state fashion, but above 300 K there is a very efficient steady-state catalytic reaction at the surface; this reaction is the decarbonylation of acetaldehyde to produce methane and carbon monoxide in the gas phase. This behaviour continues up to about 400 K. However, when acetaldehyde is dosed at 423 K, the reaction rate slowly evolves through a maximum to a very low catalytic rate. Upon carrying out reactor experiments at 473 K and above, the reaction mechanism changes to total dehydrogenation, and CO and H2 are produced at high steady-state rate, not withstanding the fact that carbon is continually being deposited onto the surface. This carbon does not appear to affect the reaction, which takes place on a surface with a c(2 × 2)-C layer present, since the extra carbon is lost from the reaction zone by diffusion into the bulk of the crystal. 相似文献
30.
Neil Hindman 《Journal of Combinatorial Theory, Series A》1979,27(1):19-32
A partition of N is called “admissible” provided some cell has arbitrarily long arithmetic progressions of even integers in a fixed increment. The principal result is that the statement “Whenever {Ai}i < r is an admissible partition of N, there are some i < r and some sequence 〈xn〉n < ω of distinct members of N such that xn + xm?Ai whenever {m, n} ? ω″ is true when r = 2 and false when r ? 3. 相似文献