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761.
Jean-Luc Chabert 《Monatshefte für Mathematik》1983,95(3):181-195
We extend Hilbert's Nullstellensatz by replacing the fieldK by an integral domainA and the polynomial ringK[X 1,...,X n ] by the ring of integral-valued polynomials with respect toA. Necessary and sufficient conditions onA are given so that this generalized version holds. 相似文献
762.
The ground state angular distributions of the reactions 9Be(p, α)6Li and 11B(p, α)8Be are analyzed by means of the DWBA theory. One-step direct mechanisms only are considered, but for both reactions the inclusion of the heavy-particle pick-up is found to be essential. DWBA fits to the data are obtained (a) in the zero-range approximation, (b) in the “fixed-range” approximation and (c) by an exact finite-range calculation. Only the latter method yields both an acceptable fit and reasonable values for the spectroscopic factors. 相似文献
763.
We present an extensive theoretical study of a self-assembled monolayer of a prototype π-conjugated thiol on Au(1 1 1). A series of experimentally accessible quantities are calculated and compared to available experimental data. After assessing the methodology and re-evaluating experimental data in the light of our theoretical results, we focus on the interfacial phenomena determining the modification of the effective workfunction of the substrate and link our findings to the energetic alignment of the frontier molecular orbitals with the metal Fermi level. Since we find no evidence of charge transfer between metal and molecule, the observed interfacial phenomena are rationalized in terms of charge fluctuations and electrostatics at the atomic length scale. The microscopic picture established in this work provides a deeper understanding of the interfacial processes that govern the working principle of single-molecule electronics and organic electronic devices. 相似文献
764.
We prove existence and regularity results for a general inequality including fixed point problems, variational and quasi variational inequalities. Examples of such problems are considered. 相似文献
765.
Jean-Luc Joly François de Thelin 《Journal of Mathematical Analysis and Applications》1976,54(1):230-244
We consider functionals of the form: If(u) = ∝Tf[t, u(t)]μ(dt), which are defined on spaces Lp(T, Rk), and we study for these functionals the properties of a convergence for which the conjugacy is a continuous operator. 相似文献
766.
767.
Jean-Luc Paillet 《Journal of Combinatorial Theory, Series B》1979,26(2):150-153
Let F be any family of subsets of a finite set E and let n be an integer, n<|F|. Under what condition does the knowledge of cardinals of m-intersections in F, for all m≤n, univocally determine the cardinal of any intersection in F, and what is the minimal condition? We give a complete answer to that. For any n, this determination property is satisfied by n if and only if |E|<2n, without further condition on F. 相似文献
768.
Laksminarayana Rao Naveen Krishna Reddy Sylvain Coulombe Jean-Luc Meunier Richard J. Munz 《Journal of nanoparticle research》2007,9(4):689-695
This communication reports on a new method for the collection of nanoparticles using carbon nanotubes (CNT) as collecting
surfaces, by which the problem of agglomeration of nanoparticles can be circumvented. CNT (10–50 nm in diameter, 1–10 μm in
length) were grown by thermal CVD at 923 K in a 7 v/v% C2H2 in N2 mixture on electroless nickel-plated copper transmission electron microscopy (TEM) grids and Monel coupons. These samples
were then placed downstream of an arc plasma reactor to collect individual copper nanoparticles (5–30 nm in diameter). It
was observed that the Cu nanoparticles preferentially adhere onto CNT and that the macro-particles (diameter >1 μm), a usual
co-product obtained with metal nanoparticles in the arc plasma synthesis, are not collected. Cu–Ni nanoparticles, a catalyst
for CNT growth, were deposited on CNT to grow multibranched CNT. CNT-embedded thin films were produced by re-melting the deposited
nanoparticles. 相似文献
769.
Abstract Herein, we introduce one of the first examples of asymmetric organocatalyzed synthesis of 1,2-dihydropyridines, affording enantioselective access to and partially solving regioselectivity challenges in the synthesis of dihydropyridines. We demonstrate that through modification of organocatalysts both 1,2- and 1,4-dihydropyridines (1,2- and 1,4-DHPs) can be obtained with high regioselectivity (ratio of 1,2-DHP/1,4-DHP from 95/5 to 0/100) and enantioselectivity (33% ee for 1,2-DHPs and up to 98% ee for 1,4-DHPs) in good yields (up to 87%). 相似文献
770.
Bridot JL Faure AC Laurent S Rivière C Billotey C Hiba B Janier M Josserand V Coll JL Elst LV Muller R Roux S Perriat P Tillement O 《Journal of the American Chemical Society》2007,129(16):5076-5084
Luminescent hybrid nanoparticles with a paramagnetic Gd2O3 core were applied as contrast agents for both in vivo fluorescence and magnetic resonance imaging. These hybrid particles were obtained by encapsulating Gd2O3 cores within a polysiloxane shell which carries organic fluorophores and carboxylated PEG covalently tethered to the inorganic network. Longitudinal proton relaxivities of these particles are higher than the positive contrast agents like Gd-DOTA which are commonly used for clinical magnetic resonance imaging. Moreover these particles can be followed up by fluorescence imaging. This study revealed that these particles suited for dual modality imaging freely circulate in the blood vessels without undesirable accumulation in lungs and liver. 相似文献