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891.
Laurent Lafforgue 《Inventiones Mathematicae》2002,147(1):1-241
One proves Langlands’ correspondence for GL
r
over function fields. This is a generalization of Drinfeld’s proof in the case of rank 2 : Langlands’ correspondence is realized
in ℓ-adic cohomology spaces of the modular varieties classifying rank r Drinfeld shtukas.
Oblatum 13-X-2000 & 7-VI-2001?Published online: 12 October 2001 相似文献
892.
Geraud Bouwmans Vincent Pureur Aurelie Betourne Yves Quiquempois Mathias Perrin Laurent Bigot Marc Douay 《Optical and Quantum Electronics》2007,39(12-13):949-961
We investigate both experimentally and numerically confinement and bend losses in solid-core photonic bandgap fibers. We proposed two designs, based on the addition of air regions in the cladding, allowing these losses to be reduced significantly while keeping the optical properties of bandgap fibers. We also present and discuss numerical results on the impact of transversal defects on the fiber confinement loss in the case of a realistic low loss fiber. 相似文献
893.
V. N. Panteleev O. Alyakrinskiy A. Andrighetto A. E. Barzakh M. Dubois C. Eleon S. Essabaa O. Bajeat D. V. Fedorov G. Gaubert A. M. Ionan V. S. Ivanov P. Jardin A. Lanchais C. Lau R. Leroy G. Lhersonneau C. Mhamed K. A. Mezilev P. L. Molkanov F. V. Moroz S. Yu. Orlov V. Rizzi M. G. Saint Laurent L. Stroe L. B. Tecchio A. C.C. Villari Yu. M. Volkov 《The European physical journal. Special topics》2007,150(1):297-300
The capacity of uranium carbide target materials of
different structure and density for production of neutron-rich and
heavy neutron-deficient nuclides have been investigated. The
yields of Cs and Fr produced by a 1 GeV proton beam of the PNPI
synchrocyclotron and release properties of different targets have
been measured. Yields and release efficiencies of Cs and Fr
produced from a high density UC target material and from low
density UCx prepared by the ISOLDE method at IRIS in the
collaboration with PARRNe group from Orsay are compared. The
yields from ISOLDE original target are presented for comparison as
well. 相似文献
894.
Laurent Stolovitch 《Publications Mathématiques de L'IHéS》2005,102(1):99-165
Let X be a germ of holomorphic vector field at the origin of Cn and vanishing there. We assume that X is a good perturbation of a “nondegenerate” singular completely integrable system.
The latter is associated to a family of linear diagonal vector fields which is assumed to have nontrivial polynomial first
integrals (they are generated by the so called “resonant monomials”). We show that X admits many invariant analytic subsets
in a neighborhood of the origin. These are biholomorphic to the intersection of a polydisc with an analytic set of the form
“resonant monomials = constants”. Such a biholomorphism conjugates the restriction of X to one of its invariant varieties
to the restriction of a linear diagonal vector field to a toric variety. Moreover, we show that the set of “frequencies” defining
the invariant sets is of positive measure. 相似文献
895.
Alkynyldimethylaluminum reagents react with various aromatic and aliphatic acid chlorides in a fast and efficient way. This reaction provides a simple entry to numerous ynones, using readily available, inexpensive, and nontoxic metalating agent, and does not require any transition metal as a catalyst. 相似文献
896.
Guignard C Jouve L Bogéat-Triboulot MB Dreyer E Hausman JF Hoffmann L 《Journal of chromatography. A》2005,1085(1):137-142
A mass spectrometer was coupled to high-performance anion-exchange chromatography (HPAEC) with the help of electrochemical neutralization of the eluent and post-column addition of lithium chloride for carbohydrate analysis. Parallel selective channels (single ion monitoring) were used to decrease the detection limits and separate unresolved peaks. The mass specific detection allowed the simultaneous analysis of a wide range of sugar alcohols, mono-, di- and oligosaccharides. Carbohydrates extracted from leaves of poplar submitted to drought stress were analyzed using pulsed amperometric detection (PAD), then mass spectrometry. It allowed the confirmation of peak attribution and the identification of salicin as a major compound in the extracts. Different responses to water deficit and re-hydration were obtained for several carbohydrates, suggesting different roles in osmoprotection processes. 相似文献
897.
898.
Collings JC Parsons AC Porrès L Beeby A Batsanov AS Howard JA Lydon DP Low PJ Fairlamb IJ Marder TB 《Chemical communications (Cambridge, England)》2005,(21):2666-2668
Donor-acceptor phenylene ethynylene systems containing the 6-methylpyran-2-one group, synthesized via classic or microwave-assisted Sonogashira cross-coupling, exhibit pronounced solvatochromism in fluorescence suggesting a highly polar excited state; 4-[4-(4-N,N-dihexylaminophenylethynyl)phenylethynyl]-6-methylpyran-2-one has a fluorescence quantum yield >0.9 in cyclohexane. 相似文献
899.
Two coumarin-labeled lysines were conveniently prepared as fluorescent probes. 7-Methoxy and 7-diethylamino coumarin-3-carboxylic acids were synthesized according to a modification of known procedures. Labeling at lysine was achieved in solution via the active N-hydroxysuccinimide ester of the carboxylic acid coumarin derivatives to give the target compounds in good yield. Spectroscopic data (UV-vis and fluorescence) were recorded for all compounds. 相似文献
900.
The mechanisms of laser ablation in silicon are investigated close to the threshold energy for pulse durations of 500 fs and 50 ps. This is achieved using a unique model coupling carrier and atom dynamics within a unified Monte Carlo and molecular-dynamics scheme. Under femtosecond laser irradiation, isochoric heating and rapid adiabatic expansion of the material provide a natural pathway to phase explosion. This is not observed under slower, nonadiabatic cooling with picosecond pulses where fragmentation of the hot metallic fluid is the only relevant ablation mechanism. 相似文献