排序方式: 共有34条查询结果,搜索用时 140 毫秒
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Damla Durak Anıl Delikanlı Cahit Demetgül İbrahim Kani Selahattin Serin 《Transition Metal Chemistry》2013,38(2):199-206
An unsymmetrical tetradentate Schiff base (H2L) was synthesized by the reaction of 3-methoxysalicylaldehyde, o-phenylenediamine, and salicylaldehyde in EtOH. H2L was characterized by single-crystallographic X-ray analysis. Its Co(II) and Mn(III) complexes ([CoL] and [MnLCl]) were prepared and immobilized on 3-aminopropyltriethoxysilane functionalized silica gel. The immobilized materials were found to be efficient catalysts for epoxidation of styrene in the presence of tert-BuOOH in acetonitrile at 40 °C. The catalysts can be reused several times without significant loss of performance. 相似文献
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We study a first-order method to find the minimum cross-sectional area ellipsoidal cylinder containing a finite set of points. This problem arises in optimal design in statistics when one is interested in a subset of the parameters. We provide convex formulations of this problem and its dual, and analyze a method based on the Frank–Wolfe algorithm for their solution. Under suitable conditions on the behavior of the method, we establish global and local convergence properties. However, difficulties may arise when a certain submatrix loses rank, and we describe a technique for dealing with this situation. 相似文献
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The main result of this paper states that any 2-quasi-umbilical hypersurface of a semi-Riemannian conformally flat space is a manifold with pseudosymmetric Weyl tensor. 相似文献
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N. F. Çam G. Yaprak M. N. Erduran 《Journal of Radioanalytical and Nuclear Chemistry》1999,242(2):273-278
FNAA has been, for many years, a technique for the non-destructive analysis of a wide variety of sample materials-liquids,
solids and powders. The important advantages of fast neutron activation analysis are good analytical sensitivity without sample
preparation, accuracy and total analysis in a short time. In our work, the concentrations of the elements Na, Mg, Al, Si,
K, Cl, Ca and Fe, were determined in cigarette tobacco of two brands commercially available in, Turkey using 14.6 MeV neutron
activation analysis. 相似文献
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D Ozcelik BS Phillips JW Parks P Measor D Gulbransen AR Hawkins H Schmidt 《Lab on a chip》2012,12(19):3728-3733
We present the first integration of fluidically tunable filters with a separate particle detection channel on a single planar, optofluidic chip. Two optically connected, but fluidically isolated liquid-core antiresonant reflecting optical waveguide (ARROW) segments serve as analyte and spectral filter sections, respectively. Ultrasensitive detection of fluorescent nanobeads with high signal-to-noise ratio provided by a fluidically tuned excitation notch filter is demonstrated. In addition, reconfigurable filter response is demonstrated using both core index tuning and bulk liquid tuning. Notch filters with 43 dB rejection ratio and a record 90 nm tuning range are implemented by using different mixtures of ethylene glycol and water in the filter section. Moreover, absorber dyes and liquids with pH-dependent transmission in the filter channel provide additional spectral control independent of the waveguide response. Using both core index and pH control, independent filter tuning at multiple wavelengths is demonstrated for the first time. This extensive on-chip control over spectral filtering as one of the fundamental components of optical particle detection techniques offers significant advantages in terms of compactness, cost, and simplicity, and opens new opportunities for waveguide-based optofluidic analysis systems. 相似文献
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D Koylu S Sarrafpour J Zhang S Ramjattan MJ Panzer SW Thomas Iii 《Chemical communications (Cambridge, England)》2012,48(76):9489-9491
This paper describes thin films comprising acenes dispersed in a conjugated polymeric host that have a ratiometric photoluminescence response to singlet oxygen. These films also respond to irradiation of protein-bound sensitizers, which represents a solution to the problem of protein-conjugated polymer non-specific interactions. 相似文献
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Sarav B. Jhaveri Damla Koylu Dominik Maschke Kenneth R. Carter 《Journal of polymer science. Part A, Polymer chemistry》2007,45(9):1575-1584
An easy and novel approach to the synthesis of functionalized nanostructured polymeric particles is reported. The surfactant‐free emulsion polymerization of methyl methacrylate in the presence of the crosslinking reagent 2‐ethyl‐2‐(hydroxy methyl)‐1,3‐propanediol trimethacrylate was used to in situ crosslink colloid micelles to produce stable, crosslinked polymeric particles (diameter size ~ 100–300 nm). A functionalized methacrylate monomer, 2‐methacryloxyethyl‐2′‐bromoisobutyrate, containing a dormant atom transfer radical polymerization (ATRP) living free‐radical initiator, which is termed an inimer (initiator/monomer), was added to the solution during the polymerization to functionalize the surface of the particles with ATRP initiator groups. The surface‐initiated ATRP of different monomers was then carried out to produce core–shell‐type polymeric nanostructures. This versatile technique can be easily employed for the design of a wide variety of polymeric shells surrounding a crosslinked core while keeping good control over the sizes of the nanostructures. The particles were characterized with scanning electron microscopy, transmission electron microscopy, optical microscopy, dynamic light scattering, and Raman spectroscopy. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1575–1584, 2007 相似文献
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