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71.
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在变化的媒体世界中,宽带载体很快也参与了"围绕媒体内容的竞争",这对于从事印刷信息的企业也是如此.在新的条件下,把他们的品牌、甚至制作的内容以及多年的经验都运用在竞争的优势中.本文旨在介绍宽带的竞争,以激励德国出版业未来的发展情况. 相似文献
73.
Bernd-Michael Neumann Hans-Georg Henning Dieter Gloyna Margit Bandlow 《Advanced Synthesis \u0026amp; Catalysis》1976,318(5):823-834
Sydnone Ethylenes. I Stereoselective Synthesis of Sydnone Ethylenes from Sydnone Aldehydes Sydnones are formylated in 4-position by the VILSMEIER -HAAK reaction. N(3)-Methyl- and N(3)-(p-Anisyl)-sydnone-(4)-carboxaldehyde react stereoselectively to sydnone ethylenes with diethyl ethoxycarbonylmethanephosphonate by HORNER reaction and with arylmethylphosphonium salts by WITTIG reaction in the presence of strong bases. In the latter case, especially in the absence of lithium cations, Z-selectivity is observed which is explained by electronic interaction between the sydnone cyclus and the aromatic substituent of the phosphine ylid in the first step of the reaction. The configuration of the obtained Z- and E-sydnone ethylenes is determined by means of 1H-NMR- and IR-spectra. 相似文献
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Recent research has compared different usability evaluation methods with respect to their effectiveness and efficiency. The paper analyses the impact of different usability evaluation methods on design problem-solving processes of individual designers and evaluators. It is proposed that usability evaluation methods have to be divided into two categories according to their fundamentally different way of supporting the design for usability: (1) guideline-based methods and (2) methods based on the mental generation of scenarios and anticipation of user goals. We present data from an experimental study that shows that these two types of methods entail differences in the perspective-taking processes. Furthermore, the results indicate that the methods have a differential impact on the general problem-solving strategy, i.e. whether to use a top-down, breadth-first or a depth-first approach. Possible implications for the development of techniques that support the design of usable systems are discussed. 相似文献
76.
Peter T. Witte Peter H. Berben Susan Boland Evert H. Boymans Dieter Vogt John W. Geus Johannes G. Donkervoort 《Topics in Catalysis》2012,55(7-10):505-511
An innovative BASF catalyst manufacturing technology (NanoSelect?) is introduced which allows production of heterogeneous catalysts with excellent control over metal crystallite sizes. NanoSelect? technology enabled the development of Pd catalysts which are lead-free Lindlar catalyst replacements in alkyne-to-cis-alkene hydrogenations. NanoSelect? Pt catalysts showed excellent chemoselectivity in substituted nitro-arene hydrogenation reactions without build-up of hydroxylamine intermediates. All NanoSelect? produced catalysts show markedly higher activity per gram of metal leading to ten-fold less use of precious metal. 相似文献
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Dieter Schütt† 《控制论与系统》2013,44(4):69-73
Abstract This note completes the author's study of embedding of cascade products of permutation or reset automata in so-called shift register graphs. 相似文献
80.
J Wuttke A Budwig M Drochner H Kämmerling FJ Kayser H Kleines V Ossovyi LC Pardo M Prager D Richter GJ Schneider H Schneider S Staringer 《The Review of scientific instruments》2012,83(7):075109
SPHERES is a third-generation neutron backscattering spectrometer, located at the 20 MW German neutron source FRM II and operated by the Ju?lich Centre for Neutron Science. It offers an energy resolution (fwhm) better than 0.65 μeV, a dynamic range of ±?31 μeV, and a signal-to-noise ratio of up to 1750:1. 相似文献