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An aeronautical measurement campaign for the satellite channel at the K band and an aeronautical multimedia service demonstration campaign for high data rate satellite services at the K/Ka band aim to provide high data rate services for all kinds of mobile terminals 相似文献
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mer ‐[Re(py)3FI2], a Mixed Fluoro Iodo Pyridine Complex of Trivalent Rhenium The title compound has been prepared from ReI3, Tl(OC2H5) and benzoylfluoride in pyridine. The substance was characterized by elemental analysis and by a crystal structure determination. Space group P 1, Z = 2, lattice dimensions at 20 °C: a = 8.266(3), b = 8.710(3), c = 13.707(4) Å, α = 100.55(2), β = 103.87(2), γ = 100.99(2)°. The Re atom is nearly octahedrally coordinated and the pyridine ligands are in mer positions. 相似文献
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Jahn A. Holzbock M. Muller J. Kebel R. de Sanctis M. Rogoyski A. Trachtman E. Franzrahe O. Werner M. Fun Hu 《Communications Magazine, IEEE》2003,41(7):36-43
The demand to make air travel more pleasant, secure, and productive for passengers is one of the winning factors for both airlines and the aircraft manufacturing industry for which aeronautical communications is one of the enablers. This article describes current trends in the area of aeronautical passenger communication toward personal and wireless in-cabin communications and multimedia data networks. Technological challenges are summarized as well as market potentials and regulatory issues. 相似文献
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A. Hinsch J. M. Kroon R. Kern I. Uhlendorf J. Holzbock A. Meyer J. Ferber 《Progress in Photovoltaics: Research and Applications》2001,9(6):425-438
Accelerated ageing tests on large numbers of nanocrystalline dye‐sensitised solar cells (nc‐DSC) show that, to first order, separation between the effects of the stresses of visible light soaking, UV illumination and thermal treatment on long‐term stability is possible. The corresponding mechanisms are electrochemical, photochemical and purely chemical in nature. It was found that visible light soaking alone is not a dominant stress factor. A dramatic improvement in UV stability has been achieved by using MgI2 as additive to the electrolyte. Thermal stress appears to be one of the most critical factors determining the long‐term stability of nc‐DSC and is strongly related to the chemical composition of electrolyte solvents and additives. Encouraging stability results have been obtained for cells based on pure nitrile‐based solvents: (1) A minor decrease in performance of initially 5.5% solar efficient cells has been found after 2000 h at 60°C without light soaking; (2) After 900 h ageing at 85°C, a decrease of 30% in maximum power has been observed; (3) After 3400 h of combined thermal stress and continuous light soaking (45°C, 1 sun equivalent) good stability with 15% decrease in maximum power can be demonstrated. It should be noted that such good thermal stability has not been reported previously for dye‐sensitised solar cells so far. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
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Synthesis and Crystal Structures of the Complexes trans ‐[CoIII(py)4F2][H2F3] and [Pd(py)4]F2 · 1.5 HF · 2 H2O The cobalt complex trans‐[Co(III)(py)4F2][H2F3] ( 1 ) has been prepared by electrochemical oxidation of CoF2 in a pyridine/HF mixture and the palladium complex [Pd(py)4]F2 · 1.5 HF · 2 H2O ( 2 ) has been obtained via halogen exchange between Pd(py)2Cl2 and AgF2 in pyridine. 1 and 2 crystallize in the space group C2/c with a = 27.928(14), b = 9.019(3), c = 18.335(8) Å, β = 113.41(3)° for 1 and a = 28.183(9), b = 9.399(3), c = 17.397(6) Å, β = 104.66(3)° for 2 , respectively. Concerning the shape and location of the M(py)4 fragments 1 and 2 are isostructural. The metal atoms occupy special positions in their unit cells with the result that four complex atoms have C2 symmetry and four complex cations have Ci symmetry giving a total of Z = 8. In 1 two F– ions complete an octahedral coordination around the Co atoms (Co–F 1.820(2) to 1.834(3) Å). In 2 the shortest Pd–F distance is 3.031(2) Å. This precludes the existence of Pd–F bonds. In 1 one can identify H2F3– groups. In 2 there are larger aggregates, consisting of F–, HF, and H2O subunits, connected by H‐bridges. In spite of these differences, both complexes belong to the same type of structure, which may be of a common type Mx+(py)4Fx · y HF · z H2O. 相似文献
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