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A polyphosphide of the type (NaP)X 1 was obtained from red phosphorus and sodium in presence of small amounts of naphthalene in 1,2-dimethoxyethane as solvent. 1 reacts with alkyl halides in dependence on the kind of alkyl group with formation of different alkylcyclophosphanes. As definite compounds Me5P5 2 , Et5P5 3 (with not definite constitution), i-Pr4P4 4 and t-Bu4P4 5 could be isolated. 1 was identified by X-ray diffraction, 2 – 5 by means of their 1H, 13C, 31P n.m.r. and mass spectra. The molecular structure of 4 was identified by electron diffraction. 相似文献
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Zoltán Buczolich Gunther Leobacher Alexander Steinicke 《Mathematische Nachrichten》2023,296(10):4778-4805
We construct a Hölder continuous function on the unit interval which coincides in uncountably (in fact continuum) many points with every function of total variation smaller than 1 passing through the origin. We conclude that this function has impermeable graph—one of the key concepts introduced in this paper—and we present further examples of functions both with permeable and impermeable graphs. Moreover, we show that typical (in the sense of Baire category) continuous functions have permeable graphs. The first example function is subsequently used to construct an example of a continuous function on the plane which is intrinsically Lipschitz continuous on the complement of the graph of a Hölder continuous function with impermeable graph, but which is not Lipschitz continuous on the plane. As another main result, we construct a continuous function on the unit interval which coincides in a set of Hausdorff dimension 1 with every function of total variation smaller than 1 which passes through the origin. 相似文献
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Archiv der Mathematik - We study the validity of the distributivity equation $$\begin{aligned} ({\mathcal {A}}\otimes {\mathcal {F}})\cap ({\mathcal {A}}\otimes {\mathcal {G}}) ={\mathcal... 相似文献
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Journal of Theoretical Probability - We present a unified approach to $$L^p$$ -solutions ( $$p > 1$$ ) of multidimensional backward stochastic differential equations (BSDEs) driven by... 相似文献
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Preparation and Reactions of Sodium Telluride, Na2Te – Crystal Structure of [Na(CH3OH)3]2Te2 Sodium telluride, Na2Te 1 , is easily obtained by reaction of sodium with hexagonal tellurium in 1,2-dimethoxy-ethane in the presence of catalytic amounts of naphthalene. Upon exposure to oxygen 1 reacts with methanol forming [Na(CH3OH)3]2Te2 2 , which crystal structure was determined. Compound 1 , prepared in situ, can be conveniently converted into dialkyl tellurides, R2Te (R = C2H5, i-C3H7, CH2 = CH? CH2 3 ). 相似文献
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Christensen H Christiansen MS Petersen J Jensen HH 《Organic & biomolecular chemistry》2008,6(18):3276-3283
A direct, mild and efficient protocol for the preparation of beta-glycosides of N-acetyl glucosamine (GlcNAc) and N-acetyl galactosamine (GalNAc) has been developed using peracetylated beta-GlcNAc and beta-GalNAc as donors. All rare Earth metal triflate promoters screened were found to promote glycosylation with Sc(OTf)(3) being superior in terms of reaction rate. Simple alcohol glycosylation was found to proceed smoothly in refluxing dichloromethane, whereas higher temperatures under microwave conditions were needed to attain acceptable yields with less reactive, carbohydrate based glycosyl acceptors. The protocol developed was applied to provide the first example of direct chemical formation of a disaccharide using both GlcNAc as a glycosyl donor and acceptor. The alpha-acetate donor was found to be significantly less reactive than the corresponding beta-anomer necessitating higher reaction temperatures under which glycoside anomerisation was found to occur. It was established, that the anomerisation only took place in the presence of both Sc(OTf)(3) and acetic acid. 相似文献
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Annals of Global Analysis and Geometry - We investigate the maximal open domain $${\mathscr {E}}(M)$$ on which the orthogonal projection map p onto a subset $$M\subseteq {{\mathbb {R}}}^d$$ can be... 相似文献
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