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61.
Matthew Wallace Andre Zamith Cardoso Dr. William J. Frith Dr. Jonathan A. Iggo Dr. Dave J. Adams 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(50):16484-16487
The magnetic‐field‐induced alignment of the fibrillar structures present in an aqueous solution of a dipeptide gelator, and the subsequent retention of this alignment upon transformation to a hydrogel upon the addition of CaCl2 or upon a reduction in solution pH is reported. Utilising the switchable nature of the magnetic field coupled with the slow diffusion of CaCl2, it is possible to precisely control the extent of anisotropy across a hydrogel, something that is generally very difficult to do using alternative methods. The approach is readily extended to other compounds that form viscous solutions at high pH. It is expected that this work will greatly expand the utility of such low‐molecular‐weight gelators (LMWG) in areas where alignment is key. 相似文献
62.
Maryam Khaleel Andrew J. Wagner Prof. K. Andre Mkhoyan Prof. Michael Tsapatsis 《Angewandte Chemie (International ed. in English)》2014,53(36):9456-9461
A structural study of a hierarchical zeolite X, which is similar to the one first synthesized by Inayat et al., 12 was performed using transmission electron microscopy imaging and diffraction. Evidence is provided, by comparison to simulations, that this material is an intergrowth of FAU and EMT and a conceptual model is presented for the growth of the FAU material with a small fraction of EMT in an atypical morphology of assembled sheets with well‐defined intersection angles. 相似文献
63.
Macromolecule Loading into Spherical,Elliptical, Star‐Like and Cubic Calcium Carbonate Carriers
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Dr. Bogdan V. Parakhonskiy Dr. Alexey M. Yashchenok Dr. Senem Donatan Dr. Dmitry V. Volodkin Dr. Francesco Tessarolo Prof. Renzo Antolini Prof. Helmuth Möhwald Prof. Andre G. Skirtach 《Chemphyschem》2014,15(13):2817-2822
We fabricated calcium carbonate particles with spherical, elliptical, star‐like and cubical morphologies by varying relative salt concentrations and adding ethylene glycol as a solvent to slow down the rate of particle formation. The loading capacity of particles of different isotropic (spherical and cubical) and anisotropic (elliptical and star‐like) geometries is investigated, and the surface area of such carriers is analysed. Potential applications of such drug delivery carriers are highlighted. 相似文献
64.
Celest Samyn Goedele Claes Marcel van Beylen Anneleen De Wachter Andre Persoons 《Macromolecular Symposia》1996,102(1):145-158
The synthesis and second harmonic coefficients, d3,1 and d3,3 as well as the related susceptibilities χ(2)zzz of five series of (NLO-dye methacrylate)-(methyl methacrylate) copolymers were investigated. The NLO-chromophores bound covalently to the polymer backbone were 5-(2,2-dicyanovinyl)-or 4-(2-cyano-2-methoxycarbonyl)vinyl-1-piperidino-2-thiophene (P1 and P2), 4-nitro-4′-alkoxy-stilbene (P3), 4-nitro-3′-methoxy-4′-alkoxystilbene (P4) and 4-nitro-4′-alkoxy-α-cyano stilbene (P5). The second order nonlinear optical properties of corona-poled aligned thin polymer films, using a needle electrode in order to induce noncentrosymmetry, were evaluated. Nonlinear susceptibilities, χ(2)zzz, of the films were derived from the analysis of full-angle Maker fringe patterns at 1064 nm, χ(2)zzz values as high as 1.98×10−7 esu for P2 copolymers and of 1.19×10−7 esu for P3 copolymers could be achieved. 相似文献
65.
Victor B. Tinti Debora Marani Andre S. Ferlauto Fabio C. Fonseca Vincenzo Esposito Daniel Z. de Florio 《Particle & Particle Systems Characterization》2020,37(2):1900472
A fast and accurate experimental method is demonstrated to assess the fraction of exsolved metallic nanoparticles using magnetic measurements. As a benchmark, nanometric metallic nickel exsolved from (La1−xSrx)(Cr1−yNiy)O3−δ is used for its high relevance as a solid oxide fuel cell component. The method is based on the difference in the magnetic response of the exsolved metallic nickel (ferromagnetic) and Sr-doped lanthanum chromite ceramic matrix (paramagnetic). The exsolved nickel results in coherent nanoparticles pinned on the surface of the Sr-doped lanthanum chromite ceramic matrix, as evidenced by electron microscopy analyses. The results obtained indicate the procedure as a fast and sensitive method to study the exsolution of ferromagnetic nanoparticles. 相似文献
66.
Self‐Pillared,Single‐Unit‐Cell Sn‐MFI Zeolite Nanosheets and Their Use for Glucose and Lactose Isomerization
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Dr. Limin Ren Dr. Qiang Guo Prashant Kumar Marat Orazov Dandan Xu Prof. Saeed M. Alhassan Prof. K. Andre Mkhoyan Prof. Mark E. Davis Prof. Michael Tsapatsis 《Angewandte Chemie (International ed. in English)》2015,54(37):10848-10851
Single‐unit‐cell Sn‐MFI, with the detectable Sn uniformly distributed and exclusively located at framework sites, is reported for the first time. The direct, single‐step, synthesis is based on repetitive branching caused by rotational intergrowths of single‐unit‐cell lamellae. The self‐pillared, meso‐ and microporous zeolite is an active and selective catalyst for sugar isomerization. High yields for the conversion of glucose into fructose and lactose to lactulose are demonstrated. 相似文献
67.
Tanter M Aubry JF Gerber J Thomas JL Fink M 《The Journal of the Acoustical Society of America》2001,110(1):37-47
A focusing technique based on the inversion of the propagation operator relating an array of transducers to a set of control points inside a medium was proposed in previous work [Tanter et al., J. Acoust. Soc. Am. 108, 223-234 (2000)] and is extended here to the time domain. As the inversion of the propagation operator is achieved both in space and time, this technique allows calculation of the set of temporal signals to be emitted by each element of the array in order to optimally focus on a chosen control point. This broadband inversion process takes advantage of the singular-value decomposition of the propagation operator in the Fourier domain. The physical meaning of this decomposition is explained in a homogeneous medium. In particular, a definition of the number of degrees of freedom necessary to define the acoustic field generated by an array of limited aperture in a focal plane of limited extent is given. This number corresponds to the number of independent signals that can be created in the focal area both in space and time. In this paper, this broadband inverse-focusing technique is compared in homogeneous media with the classical focusing achieved by simple geometrical considerations but also with time-reversal focusing. It is shown that, even in a simple medium, slight differences appear between these three focusing strategies. In the companion paper [Aubry et al., J. Acoust. Soc. Am. 110, 48-58 (2001)] the three focusing techniques are compared in heterogeneous, absorbing, or complex media where classical focusing is strongly degraded. The strong improvement achieved by the spatio-temporal inverse-filter technique emphasizes the great potential of multiple-channel systems having the ability to apply completely different signal waveforms on each transducer of the array. The application of this focusing technique could be of great interest in various ultrasonic fields such as medical imaging, nondestructive testing, and underwater acoustics. 相似文献
68.
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70.
J.A. Pinston W. Mampe R. Roussille K. Schreckenbach D. Heck H.G. Börner H.R. Koch S. Andre D. Barneoud 《Nuclear Physics A》1979,321(1):25-44
Gamma and electron spectra following thermal neutron capture on 99Tc have been studied with a bent-crystal spectrometer, Ge(Li) and Si(Li) detectors and a magnetic spectrometer. Prompt and delayed γ-γ coincidences with Ge(Li) detectors have been performed. A level scheme is proposed for 100Tc comprising 21 excited states up to 640 keV. The binding energy of the last neutron in 100Tc was deduced. For most levels, spin and parity values were assigned. Two isometric transitions of respective half-lives 10.2 and 4.6 μs have been identified using the 100Mo(d, 2n)100Tc reaction with a pulsed beam of deuterons. From the comparison of the present (n, γ) study and the collaborative study of the 99Tc(d, p) reaction, several members of the multiplets , , and have been identified. 相似文献