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101.
We generalize the classical Paley–Wiener theorem to special types of connected, simply connected, nilpotent Lie groups: First we consider nilpotent Lie groups whose Lie algebra admits an ideal which is a polarization for a dense subset of generic linear forms on the Lie algebra. Then we consider nilpotent Lie groups such that the co-adjoint orbits of all the elements of a dense subset of the dual of the Lie algebra 𝔤* are flat (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
102.
Matthieu Virot Valérie Tomao Carine Le Bourvellec Catherine M.C.G. Renard Farid Chemat 《Ultrasonics sonochemistry》2010,17(6):1066-1074
Apple pomace, a by-product of the cider production, has been studied as a potential source of polyphenols, compounds of great interest for the industry. Ultrasound has been used to improve extraction efficiency in terms of time needed and total polyphenol content. A preliminary study has been first investigated to optimize ethanol proportion of aqueous extractant (50%, v/v) and solid/liquid ratio (<15%, w/v). A response surface methodology has then been used to maximize total polyphenol content of extracts and investigate influence of parameters involved in extraction procedures for both total polyphenols content and composition of extracts. Optimal settings reached from a central composite design were applied for ultrasound-assisted extraction and were compared to conventional procedure: yields were increased by more than 20%. Ultrasound-assisted polyphenols extraction from apple pomace appears to be a relevant, rapid, sustainable alternative to conventional procedure, and that scale up of the process is possible. 相似文献
103.
Paul M. Forster Andrea R. Burbank Melanie C. O'Sullivan Nathalie Guillou Carine Livage Grard Frey Norbert Stock Anthony K. Cheetham 《Solid State Sciences》2005,7(12):1549
A new form of cobalt succinate has been discovered using high-throughput methods and its structure was solved by single crystal X-ray diffraction. Co7(C4H4O4)4(OH)6(H2O)37H2O crystallizes in the monoclinic space group P21/c with cell parameters: a=7.888(2) Å, b=19.082(6) Å, c=23.630(7) Å, β=91.700(5)°, V=3555(2) Å3, R1=0.0469. This complex structure, containing 55 crystallographically distinct non-hydrogen atoms, is compared to the previously reported nickel phase, characterized using ab initio structure solution from synchrotron powder diffraction data. 相似文献
104.
105.
The long-term storage behaviour of methylmercury at different concentrations in distilled, deionized water was studied under various storage conditions. The stability is strongly dependent on concentration, the container material and the storage temperature. Container pretreatment also has an influence. Light seems to have no effect on the stability of methylmercury solutions. 相似文献
106.
The reaction of fluoride ion with 7‐phosphanorbornadiene P–W(CO)5 complexes yields fluorophosphido complexes which, in turn, can attack a second molecule of 7‐phosphanorbornadiene to give a fluorobiphosphine complex. The corresponding anion displays a huge P–P coupling. The structure of the anionic chromium analogue has been investigated by DFT calculations. The P–P bond is relatively short at 2.20 Å and displays a huge polarity suggesting an interesting chemistry. When the 7‐phosphanorbornadiene P‐substituent is 2‐chloroethyl, the attack of the fluoride ion is followed by a cyclization and a reductive dimerization leading to the first known biphosphirane complex. 相似文献
107.
Brissard M Convert O Gruselle M Guyard-Duhayon C Thouvenot R 《Inorganic chemistry》2003,42(4):1378-1385
In this paper, we describe the enantiospecific synthesis and the complete characterization of the two hexacoordinated ruthenium(II) monocations [Ru(bpy)(2)ppy](+) and [Ru(bpy)(2)quo](+) (bpy = 2,2'-bipyridine, ppy = phenylpyridine-H(+), quo = 8-hydroxyquinolate) in their enantiomeric Delta and Lambda forms. The corresponding enantiomeric excesses (ee's) are determined by (1)H NMR using pure Delta-Trisphat (tris(tetrachlorobenzenedialato)phosphate(V) anion) as a chiral (1)H NMR shift reagent. A complete (1)H and (13)C NMR study has been carried out on rac-[Ru(bpy)(2)ppy]PF(6) and rac-[Ru(bpy)(2)quo]PF(6). Additionally, the X-ray molecular structure of rac-[Ru(bpy)(2)quo]PF(6) is reported; this latter species crystallizes in the monoclinic C2/c space group (a = 22.079 A, b = 16.874 A, c = 17.533 A, alpha = 90 degrees, beta = 109.08 degrees, gamma = 90 degrees ). 相似文献
108.
Gerhard Baum Alexander J. Blake Dieter Fenske Peter Hubberstey Carine Julio Matthew A. Withersby 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(11):m542-m544
Molecules of the title compound, [Cu(C2H3N)(C11H9N5)(C6H6N2O)](BF4)2·2C2H3N, comprise (acetonitrile)[2,6‐bis(pyrazol‐1‐yl)pyridine](isonicotinamide)copper(II) cations, tetrafluoroborate anions and lattice acetonitrile molecules. The cations have distorted square‐pyramidal geometries in which the N3‐donor, viz. 2,6‐bis(pyrazol‐1‐yl)pyridine, and the N‐donor, viz. the isonicotinamide ligand, occupy the four basal positions, with the coordinated acetonitrile N‐donor atom occupying the apical position. Pairs of cations are linked by N—H?F hydrogen bonds through tetrafluoroborate anions, forming centrosymmetric dimers, which are further linked by C—H?O hydrogen bonds into two‐dimensional undulating sheets, three of which interpenetrate to generate a two‐dimensional network. 相似文献
109.
The main objectives of the present work were the synthesis of the two cis diastereomers of 5,6-dihydroxy-5,6-dihydro-5-methyl-2'-deoxycytidine and the kinetic study of their hydrolytic deamination. The preparation of the two glycols, two main (*)OH-mediated oxidation products of 5-methyl-2'-deoxycytidine, was achieved in two steps. The first one involved the synthesis of the two trans-(5R,6S)- and (5S,6R)-5-bromo-6-hydroxy-5,6-dihydro-5-methyl-2'-deoxycytidine. In a subsequent step, the bromohydrins were specifically converted into the cis-(5S,6S) and (5R,6R) diastereomers of 5,6-dihydroxy-5,6-dihydro-5-methyl-2'-deoxycytidine, respectively, under slightly alkaline conditions. The resulting glycols were purified by reverse phase high performance liquid chromatography and characterized by extensive spectroscopy measurements including (13)C- and (1)H-NMR analyses. Exact mass determination was inferred from high resolution fast atom bombardment mass spectrometry measurements. Circular dichroism spectroscopy confirmed the diastereomeric relationship existing between the pair of glycols. Kinetic study of the deamination of the above glycols was carried out in phosphate buffer solutions (pH 7) at two different temperatures (37 degrees C and 25 degrees C) in order to determine the thermodynamic and kinetic parameters of the reaction. 相似文献
110.
Douarche C Cortès R Roser SJ Sikorav JL Braslau A 《The journal of physical chemistry. B》2008,112(44):13676-13679
DNA adsorption on solid or liquid surfaces is a topic of broad fundamental and applied interest. Here, we study by X-ray reflectivity the adsorption of monodisperse double-stranded DNA molecules on a positively charged surface, obtained through chemical grafting of a homogeneous organic monomolecular layer of N-(2-aminoethyl) dodecanamide on an oxide-free monocrystalline Si(111) wafer. The adsorbed dsDNA is found to embed into the soft monolayer, which is deformed in the process. The surface coverage is very high, and this adsorbed layer is expected to display 2D nematic ordering. 相似文献