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排序方式: 共有94条查询结果,搜索用时 234 毫秒
11.
We showexistence and uniqueness of L∞-solutions to stochastic continuity equations with Ladyzhenskaya-Prodi-Serrin condition. The main issue of uniqueness is proved reeling on stochastic characteristic method. 相似文献
12.
Christel Roux Wladimir Gorecki Jean-Yves Sanchez Elie Belorizky 《Macromolecular Symposia》1997,114(1):211-216
High molecular weight polymers have been prepared by ring-opening polymerization of propylene oxide PO using a Vandenberg initiator. Polymer electrolytes based on this polymer and an imide salt LiTFSI have been investigated. We present the results concerning the synthesis of the polymer and the glass transition temperatures evolution of the complexes with respect to salt composition. Diffusion constants of 19F and 7Li nuclei are determined by NMR techniques and a value of the cationic transport number t+ = 0.1 is obtained. 相似文献
13.
Aberration characterization for the optimal design of high-resolution endoscopic optical coherence tomography catheters 总被引:1,自引:0,他引:1
We study the major factors causing degradation in the lateral resolution of gradient-index-lens-based catheters used for high-resolution optical coherence tomography. Chromatic aberration and astigmatism were taken into account in the propagation of broadband single-mode Gaussian beams through the catheter geometry. It was found that, while chromatic aberration did not preclude achieving high resolution, astigmatism posed a major technical difficulty, because its correction requires a very sensitive adjustment of parameters, especially for catheters with long working distances. 相似文献
14.
Dr. Etienne Borré Dr. Mathieu Rouen Isabelle Laurent Magaly Magrez Dr. Fréderic Caijo Dr. Christophe Crévisy Dr. Wladimir Solodenko Loic Toupet René Frankfurter Prof. Dr. Carla Vogt Prof. Dr. Andreas Kirschning Dr. Marc Mauduit 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(51):16369-16382
In this study, a new pyridinium‐tagged Ru complex was designed and anchored onto sulfonated silica, thereby forming a robust and highly active supported olefin‐metathesis pre‐catalyst for applications under batch and continuous‐flow conditions. The involvement of an oxazine–benzylidene ligand allowed the reactivity of the formed Ru pre‐catalyst to be efficiently controlled through both steric and electronic activation. The oxazine scaffold facilitated the introduction of the pyridinium tag, thereby affording the corresponding cationic pre‐catalyst in good yield. Excellent activities in ring‐closing (RCM), cross (CM), and enyne metathesis were observed with only 0.5 mol % loading of the pre‐catalyst. When this powerful pre‐catalyst was immobilized onto a silica‐based cationic‐exchange resin, a versatile catalytically active material for batch reactions was generated that also served as fixed‐bed material for flow reactors. This system could be reused at 1 mol % loading to afford metathesis products in high purity with very low ruthenium contamination under batch conditions (below 5 ppm). Scavenging procedures for both batch and flow processes were conducted, which led to a lowering of the ruthenium content to as little as one tenth of the original values. 相似文献
15.
In this work new polymer/carrier composites are described which serve as novel materials in flow-through reactors for polymer-supported organic solution-phase synthesis. Monolithic polymer/carrier columns are prepared by a new precipitation polymerization process inside the void pore volume of megaporous glass carrier materials. Chemical functionalization of the internal polymer phase with chlorosulfonic acid or trimethylamine generates small, interconnected ion-exchange resin beads with a diameter of 1-3 microm which can be used for a large variety of organic syntheses. These monolithic rods are incorporated into an appropriate casing and can conveniently be operated in the flow-through mode. Important successful applications are polymer-assisted solution-phase reductions, oxidations and Horner-Emmons olefinations. Additionally, the use of these monolithic columns as catalytic microreactors and their performance in selected reactions are described. 相似文献
16.
Miguel E. Alonso Reinaldo Compagnone Wladimir Chitty 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-2):9-10
Abstract Recent studies on the fragmentation of some organic disulfides upon electron impact in a mass spectrometer have shown two main decomposition routes besides simple bond disconnection: skeletal rearrangements1–3 and proton transfer4. Transposition of the molecular components takes place via loss of one or two sulfur atoms while the carbon skeleton is preserved. Such molecular rearrangements are particularly noticeable in small molecules like dimethyl disulfide. Larger systems show a different fragmentation pattern in which proton transfer to give alkyl hydro-disulfides becomes predominant. The transfer of protons has been shown to proceed by way of intramolecular 1,2 and 1,3 hydrogen shifts from α and β carbons respectively by means of selective deuterium labbeling of diethyl disulfide.4 相似文献
17.
Wladimir Lewicki 《Monatshefte für Mathematik》1903,14(1):283-292
Ohne Zusammenfassung 相似文献
18.
Wladimir Skinder 《Analytical and bioanalytical chemistry》1912,51(10-11):670-671
19.
Wladimir de Azevedo Pribitkin 《Proceedings of the American Mathematical Society》2008,136(9):3089-3094
Under what conditions do the (possibly complex) coefficients of a general Dirichlet series exhibit oscillatory behavior? In this work we invoke Laguerre's Rule of Signs and Landau's Theorem to provide a rather simple answer to this question. Furthermore, we explain how our result easily applies to a multitude of functions.
20.
Ohne Zusammenfassung 相似文献