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991.
Didier Dominé Peter Buehlmann Julien Bailat Adrian Billet Andrea Feltrin Christophe Ballif 《固体物理学:研究快报》2008,2(4):163-165
In the effort to increase the stable efficiency of thin film silicon micromorph solar cells, a silicon oxide based intermediate reflector (SOIR) layer is deposited in situ between the component cells of the tandem device. The effectiveness of the SOIR layer in increasing the photo‐carrier generation in the a‐Si:H top absorber is compared for p–i–n devices deposited on different rough, highly transparent, front ZnO layers. High haze and low doping level for the front ZnO strongly enhance the current density (Jsc) in the μc‐Si:H bottom cell whereas Jsc in the top cell is influenced by the angular distribution of the transmitted light and by the reflectivity of the SOIR related to different surface roughness. A total Jsc of 26.8 mA/cm2 and an initial conversion efficiency of 12.6% are achieved for 1.2 cm2 cells with top and bottom cell thicknesses of 300 nm and 3 μm, and without any anti‐reflective coating on the glass. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
992.
Andr Benattar Didier Barbry Bruno Hasiak Daniel Couturier 《Journal of heterocyclic chemistry》1981,18(1):63-65
Treatment of 1,1-dimethyl-2-tolylpiperidinium halides with sodium amide in liquid ammonia affords derivatives of 2,3,4,5,6,7-hexahydro-1H-2-benzazonine via the Sommelet-Hauser rearrangement. Structures of the reaction products have been established by 13C nmr. In the case of 1,1-dimethyl-2-benzylpiperidinium halide, only an elimination reaction takes place. 相似文献
993.
994.
The role of various magnetic interchain couplings is investigated by numerical methods in doped frustrated quantum spin chains. A nonmagnetic dopant introduced in a gapped spin chain releases a free spin-1/2 soliton. The formation of a local magnetic moment is analyzed in terms of soliton confinement. A four-spin coupling which might originate from cyclic exchange is shown to produce such a confinement. Dopants on different chains experience an effective space-extended nonfrustrating pairwise spin interaction. 相似文献
995.
We study the stress response to a steady imposed shear rate in a concentrated suspension of colloidal particles. We show that, in a small range of concentrations and shear rates, stress exhibits giant fluctuations. The amplitude of these fluctuations obeys a power-law behavior, up to the apparition of a new branch of flow, leading to an excess of high amplitude fluctuations which exhibit a well-defined periodicity. 相似文献
996.
Schoeller WW Rozhenko A Bourissou D Bertrand G 《Chemistry (Weinheim an der Bergstrasse, Germany)》2003,9(15):3611-3617
The concept of through-space versus through-bond interactions on the stabilization of biradical structures with a singlet or triplet ground state is evaluated for the 1,3-diboracyclobutane-1,3-diyls and related congeners. Singlet biradicals are favored when the intermediate units E feature singlet character (PH(2) (+), AsH(2) (+)), while E fragments with triplet character (NH(2) (+)) induce small energy separations between the lowest singlet and triplet states. These considerations are supported by quantum chemical calculations with energy optimization at 1) MCSCF level plus MR-MP2 correction, 2) MR-MP2 level, and 3) two different types of density functional levels for the planar (D(2h)) geometries. The singlet-triplet energy separations in the planar compounds increase with increasing singlet stability of the corresponding E fragments. In addition to this newly developed principal features for singlet stabilization, which primarily occurs in bonded structures with higher main-group elements, the corresponding valence isomers with bicyclobutane, cyclobutene and cis-butadiene structures are investigated. 相似文献
997.
Delabouglise D Marcus B Mermoux M Bouvier P Chane-Tune J Petit JP Mailley P Livache T 《Chemical communications (Cambridge, England)》2003,(21):2698-2699
Grafting of biotin on top of a polycrystalline boron-doped diamond layer was achieved by surface oxidation followed by an esterification reaction and revealed by fluorescently labelled streptavidin. 相似文献
998.
Three generations of bidentate phosphinated Pd(II) dendrimers are efficient catalysts in the absence of copper co-catalyst for the Sonogashira reaction and are, with two cyclohexyl substituents on the phosphorus atoms, recovered by precipitation and re-used. 相似文献
999.
1000.
Didier Villemin 《Tetrahedron letters》1980,21(18):1715-1718
Two syntheses of macrolides olefin methathesis are presented. The first (A) involves preparation of ω-hydroxyacid or by metathesis followed by cyclisation, while the second (B) involves macrocyclic ring closure by metathesis of a ω,ω′diunsaturated ester . 相似文献