排序方式: 共有131条查询结果,搜索用时 15 毫秒
71.
Michael Maes Maarten Trekels Mohammed Boulhout Stijn Schouteden Frederik Vermoortele Luc Alaerts Daniela Heurtaux You‐Kyong Seo Young Kyu Hwang Jong‐San Chang Isabelle Beurroies Renaud Denoyel Kristiaan Temst Andre Vantomme Patricia Horcajada Christian Serre Dirk E. DeVos 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2011,123(18):4296-4300
72.
Debin Mao Richard Lookman Hendrik Van De Weghe Dirk Van Look Guido Vanermen Nicole De Brucker Ludo Diels 《Journal of chromatography. A》2009,1216(9):1524-1527
Enhanced bioremediation of petroleum hydrocarbons in two biopiles was quantified by high-performance liquid chromatography (HPLC) followed by comprehensive two-dimensional gas chromatography (GCXGC). The attenuation of 34 defined hydrocarbon classes was calculated by HPLC–GCXGC analysis of representative biopile samples at start-up and after 18 weeks of biopile operation. In general, a-cyclic alkanes were most efficiently removed from the biopiles, followed by monoaromatic hydrocarbons. Cycloalkanes and polycyclic aromatic hydrocarbons (PAHs) were more resistant to degradation. A-cyclic biomarkers farnesane, trimethyl-C13, norpristane, pristane and phytane dropped to only about 10% of their initial concentrations. On the other hand, C29–C31 hopane concentrations remained almost unaltered after 18 weeks of biopile operation, confirming their resistance to biodegradation. They are thus reliable indicators to estimate attenuation potential of petroleum hydrocarbons in biopile processed soils. 相似文献
73.
Using a small scale test-rig a number of experiments were performed in which the imposed disk velocity v
disk, the different mechanical parameters of the test-rig (damping c and tangential stiffness k), and normal load were varied independently. 相似文献
74.
Dr. Yovan de Coene Dr. Olivier Deschaume Dr. Yuqing Zhang Arne Billen Jing He Stephanie Seré Dr. Stefan Knoppe Prof. Dr. Stijn Van Cleuvenbergen Prof. Dr. Thierry Verbiest Prof. Dr. Koen Clays Prof. Dr. Jian Ye Prof. Dr. Carmen Bartic 《Chemphyschem》2019,20(13):1765-1774
Gold nanoparticles (AuNPs) are regarded as promising building blocks in functional nanomaterials for sensing, drug delivery and catalysis. One remarkable property of these particles is the localized surface plasmon resonance (LSPR), which gives rise to augmented optical properties through local field enhancement. LSPR also influences the nonlinear optical properties of metal NPs (MNPs) making them potentially interesting candidates for fast, high resolution nonlinear optical imaging. In this work we characterize and discuss the wavelength dependence of the hyper-Rayleigh scattering (HRS) behavior of spherical gold nanoparticles (GNP) and gold nanorods (GNR) in solution, from 850 nm up to 1300 nm, covering the near-infrared (NIR) window relevant for deep tissue imaging. The high-resolution spectral data allows discriminating between HRS and two photon photoluminescence contributions. Upon particle aggregation, we measured very large enhancements (ca. 104) of the HRS intensity in the NIR, which is explained by considering aggregation-induced plasmon coupling effects and local field enhancement. These results indicate that purposely designed coupled nanostructures could prove advantageous for nonlinear optical imaging and biosensing applications. 相似文献
75.
Bram Verbelen Stijn Boodts Johan Hofkens Noël Boens Wim Dehaen 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(15):4695-4699
We describe herein the first radical C H arylation of BODIPY dyes. This novel, general, one‐step synthetic procedure uses ferrocene to generate aryl radical species from aryldiazonium salts and allows the straightforward synthesis of brightly fluorescent (Φ>0.85) 3,5‐diarylated and 3‐monoarylated boron dipyrrins in up to 86 % yield for a broad range of aryl substituents. In this way, new and complex dyes with red‐shifted spectra can be easily prepared. 相似文献
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77.
Kaval N Singh BK Ermolat'ev DS Claerhout S Parmar VS der Eycken JV der Eycken EV 《Journal of combinatorial chemistry》2007,9(3):446-453
A new transition metal-catalyzed orthogonal solid-phase protocol for the synthesis of highly substituted 2(1H)-pyrazinones was developed, on the basis of Chan-Lam arylation and Liebeskind-Srogl cross-coupling reactions. This strategy opens the way for the generation of small libraries of 2(1H)-pyrazinone analogues for biological screening. 相似文献
78.
Dr. Eduard Badarau Dr. K. Harsha Vardhan Reddy Dr. Aurore Loudet Dr. Charles Simon Dr. Laurent Trembleau Dr. Stijn Claerhout Dr. Etienne Pair Stéphane Massip Dr. Philippe Breton Dr. Brigitte Lesur Dr. Solo Goldstein Dr. Jean-Marie Fourquez Dr. Jean Michel Henlin Prof. Léon Ghosez 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(67):15477-15481
Identification of a common Diels–Alder pattern in three classes of bioactive natural products led us to study the synthesis and cycloaddition of a new class of cyclic dienes readily available from β,γ-unsaturated lactams. A practical and readily scalable route to the parent p-methoxybenzyl-protected 6- and 7-membered β,γ-unsaturated lactams was developed. These were readily transformed into the corresponding O-silylated dienes, which were reacted with dimethyl and diethyl fumarate to yield stereoselectively highly functionalized bicyclic adducts. These exhibited unexpected and versatile transformations upon acid hydrolysis depending on the nature of the dienophile substituents and the acid catalyst. All reactions have been performed on multigram quantities. These transformations provide a convenient, economical, and easily scalable pathway for the rapid construction of functionally and stereochemically dense privileged scaffolds for the construction of libraries of natural products-inspired molecules of pharmacological relevance. 相似文献
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80.
Omelchenko IV Shishkin OV Gorb L Leszczynski J Fias S Bultinck P 《Physical chemistry chemical physics : PCCP》2011,13(46):20536-20548
The degree of aromaticity of six-membered monoheterocycles with IV-VI group heteroatoms (C(6)H(5)X, where X = SiH, GeH, N, P, As, O(+), S(+), Se(+)) was analyzed using the results of ab initio calculations at the MP2/cc-pvtz level. Values of common aromaticity indices including those based on electronic delocalization properties, structural-dynamic features and magnetic properties all indicate high aromaticity of all considered heterocycles. A decrease in aromaticity is observed with increasing atomic number of the heteroatom, except in the case of the pyrylium cation. However, not all types of indices or even different indices within the same type correlate well among each other. Ring currents have been obtained at the HF/cc-pvdz level using the ipsocentric formulation. Ring current maps indicate that in the case of cationic heterocycles the ring current persists in all molecules under consideration. The different conclusions reached depending on the type of index used are a manifestation of the fact that when not dealing with hydrocarbons, aromaticity is ill-defined. One should always express explicitly which property of the molecules is considered to establish a degree of "aromaticity". 相似文献