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991.
Conway B Hevia E García-Alvarez J Graham DV Kennedy AR Mulvey RE 《Chemical communications (Cambridge, England)》2007,(48):5241-5243
Lithium TMP-aluminate "(i)Bu(3)Al(TMP)Li" undergoes dismutation in THF solution to precipitate the tetraalkylaluminate [{Li.(THF)(4)}(+){Al((i)Bu)(4)}(-)], but reacts kinetically as a TMP base towards N,N-diisopropylbenzamide to afford the crystalline ortho-aluminated species [(THF)(3).Li{O([=C)N((i)Pr)(2)(C(6)H(4))}Al((i)Bu)(3)] and TMPH. 相似文献
992.
993.
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995.
Graham DJ 《Journal of chemical information and modeling》2007,47(2):376-389
The informatic properties of organic molecules have been the subject of our research during the past several years. In the present study, we investigate the lower levels wherein information is expressed via Brownian processing. Organic molecules are like other electronic devices in that their informatic details depend on the operating level in question. The low and high levels are distinguished (among other ways) by the amount of work they require for processing. In this work, a Brownian model is developed by which the low-level content of a chemical system can be quantified. The model is demonstrated for diverse organic molecules. In so doing, several scaling properties of low-level information are illustrated. In addition, the correspondence traits regarding the different levels are examined. Molecular information represents a capacity for work control such as during chemical reactions. Thus, the information expressed at low levels is examined in connection with the reaction pathway selectivity of organic compounds. 相似文献
996.
Medlock K Harmer H Worsley G Horgan A Pritchard J 《Analytical and bioanalytical chemistry》2007,389(5):1533-1539
Conventional electrochemical methods of determining the pH of body fluids have drawbacks. Newer optical methods offer the
promise of miniaturisation and continuous in vivo measurements without drift. This report examines the ability of a holographic
sensor based on a thin-film, biocompatible hydrogel (approximately 10 μm) of poly(2-hydroxyethyl methacrylate) and ionisable
2-(dimethylaminoethyl) methacrylate to accurately measure the pH of blood plasma ex vivo. It is found that the sensors behave
in a fully reversible manner. After an initial calibration with buffers, they can measure pH over extended periods (more than
40 h).
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
997.
We develop an exact method for computing the Casimir energy between arbitrary compact objects, either dielectrics or perfect conductors. The energy is obtained as an interaction between multipoles, generated by quantum current fluctuations. The objects' shape and composition enter only through their scattering matrices. The result is exact when all multipoles are included, and converges rapidly. A low frequency expansion yields the energy as a series in the ratio of the objects' size to their separation. As an example, we obtain this series for two dielectric spheres and the full interaction at all separations for perfectly conducting spheres. 相似文献
998.
We show that, given a tempered distribution S whose Fourier transform is a function of polynomial growth, a point x in
is outside the support of S if and only if the Fourier integral of S is summable in Bochner-Riesz means to zero uniformly on a neighbourhood of x.
Received: 29 December 2005 相似文献
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1000.
Carlos G. Lopez Sarah E. Rogers Ralph H. Colby Peter Graham João T. Cabral 《Journal of Polymer Science.Polymer Physics》2015,53(7):492-501
We report a small angle neutron scattering (SANS) and rheology study of cellulose derivative polyelectrolyte sodium carboxymethyl cellulose with a degree of substitution of 1.2. Using SANS, we establish that this polymer is molecularly dissolved in water with a locally stiff conformation with a stretching parameter . We determine the cross sectional radius of the chain ( 3.4 Å) and the scaling of the correlation length with concentration (ξ = 296 c?1∕2Å for c in g/L) is found to remain unchanged from the semidilute to concentrated crossover as identified by rheology. Viscosity measurements are found to be in qualitative agreement with scaling theory predictions for flexible polyelectrolytes exhibiting semidilute unentangled and entangled regimes, followed by what appears to be a crossover to neutral polymer concentration dependence of viscosity at high concentrations. Yet those higher concentrations, in the concentrated regime defined by rheology, still exhibit a peak in the scattering function that indicates a correlation length that continues to scale as . © 2014 The Authors. Journal of Polymer Science Part B: Polymer Physics Published by Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 492–501 相似文献