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81.
Cats Peter Sitlapersad Ranisha S. den Otter Wouter K. Thornton Anthony R. van Roij René 《Journal of solution chemistry》2022,51(3):296-319
Journal of Solution Chemistry - We present a study of the structure and differential capacitance of electric double layers of aqueous electrolytes. We consider electric double layer capacitors... 相似文献
82.
Haojie Zhang Dr. Dirk J. Hagen Prof. Xiaopeng Li Dr. Andreas Graff Dr. Frank Heyroth Dr. Bodo Fuhrmann Dr. Ilya Kostanovskiy Dr. Stefan L. Schweizer Dr. Francesco Caddeo Prof. A. Wouter Maijenburg Prof. Stuart Parkin Prof. Ralf B. Wehrspohn 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(39):17324-17329
83.
Tribenzotriquinacene Receptors for C60 Fullerene Rotors: Towards C3 Symmetrical Chiral Stators for Unidirectionally Operating Nanoratchets 下载免费PDF全文
Dr. Björn Bredenkötter Dr. Maciej Grzywa Dr. Mohammad Alaghemandi Dr. Rochus Schmid Prof. Dr. Wouter Herrebout Prof. Dr. Patrick Bultinck Prof. Dr. Dirk Volkmer 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(29):9100-9110
The synthesis of a stereochemically pure concave tribenzotriquinacene receptor ( 7 ) for C60 fullerene, possessing C3 point group symmetry, by threefold condensation of C2‐symmetric 1,2‐diketone synthons ( 5 ) and a hexaaminotribenzotriquinacene core ( 6 ) is described. The chiral diketone was synthesized in a five‐step reaction sequence starting from C2h‐symmetric 2,6‐di‐tert‐butylanthracene. The highly diastereo‐discriminating Diels–Alder reaction of 2,6‐di‐tert‐butylanthracene with fumaric acid di(?)menthyl ester, catalyzed by aluminium chloride, is the relevant stereochemistry introducing step. The structure of the fullerene receptor was verified by 1H and 13C NMR spectroscopy, mass spectrometry and single crystal X‐ray diffraction. VCD and ECD spectra were recorded, which were corroborated by ab initio DFT calculations, establishing the chiral nature of 7 with about 99.7 % ee, based on the ee (99.9 %) of the chiral synthon ( 1 ). The absolute configuration of 7 could thus be established as all‐S [(2S,7S,16S,21S,30S,35S)‐( 7 )]. Spectroscopic titration experiments reveal that the host forms 1:1 complexes with either pure fullerene (C60) or fullerene derivatives, such as rotor 1′‐(4‐nitrophenyl)‐3′‐(4‐N,N‐dimethylaminophenyl)‐pyrazolino[4′,5′:1,2][60]fullerene ( R ). The complex stability constants of the complexes dissolved in CHCl3/CS2 (1:1 vol. %) are K([ C60 ? 7 ])=319(±156) M ?1 and K([ R ? 7 ])=110(±50) M ?1. With molecular dynamics simulations using a first‐principles parameterized force field the asymmetry of the rotational potential for [ R ? 7 ] was shown, demonstrating the potential suitability of receptor 7 to act as a stator in a unidirectionally operating nanoratchet. 相似文献
84.
Delanoye SN Herrebout WA van der Veken BJ 《Journal of the American Chemical Society》2002,124(25):7490-7498
Complexes of haloforms of the type HCCl(n)F(3-)(n) (n = 1-3) with dimethyl ether have been studied in liquid argon and liquid krypton, using infrared spectroscopy. For the haloform C[bond]H stretching mode, the complexation causes blue shifts of 10.6 and 4.8 cm(-1) for HCClF(2) and HCCl(2)F, respectively, while for HCCl(3) a red shift of 8.3 cm(-1) is observed. The ratio of the band areas of the haloform C[bond]H stretching in complex and monomer was determined to be 0.86(4) for HCClF(2), 33(3) for HCCl(2)F, and 56(3) for HCCl(3). These observations, combined with those for the HCF(3) complex with the same ether (J. Am. Chem. Soc. 2001, 123, 12290), have been analyzed using ab initio calculations at the MP2[double bond]FC/6-31G(d) level, and using some recent models for improper hydrogen bonding. Ab initio calculations on the haloforms embedded in a homogeneous electric field to model the influence of the ether suggest that the complexation shift of the haloform C[bond]H stretching is largely explained by the electric field effect induced by the electron donor in the proton donor. The model calculations also show that the electric field effect accounts for the observed intensity changes of the haloform C[bond]H stretches. 相似文献
85.
86.
In this tutorial review the use of stimulus-sensitive hydrogels as sensors and actuators for (micro)analytical applications is discussed. The first part of the article is aimed at making the reader familiar with stimulus-sensitive hydrogels, their chemical composition and their chemo-physical behavior. The prior art in the field, that comprises a number of sensors ranging from metal ion-sensitive sensors to antigen-sensitive sensors and a few actuators, is also treated in this part. The second part of the article focusses on the use of stimulus-sensitive hydrogels for microsensors and microactuators as well as their application in micro total analysis systems. The benefits of stimulus-sensitive hydrogels, their miniaturisation and the use of 365 nm UV-photolithography as a fast economical manufacturing technique are discussed. 相似文献
87.
A Direct Method for the Identification of the Permeability Field Based on Flux Assimilation by a Discrete Analog of Darcy's Law 总被引:3,自引:2,他引:1
Wouter Zijl 《Transport in Porous Media》2004,56(1):87-112
Inverse models to determine the permeability are generally based on existing forward models for the pressure. The permeabilities are adapted in such a way that the calculated pressures match the specified pressures in a number of points. To assimilate a priori knowledge about the flux, we introduce the flux assimilation method, which is based on the vector potential–pressure formulation of Darcy's law. Thanks to an unconventional discretization technique – the edge-based face element method – not only the specified pressures, but also specified information about the flux density can easily be assimilated. A relatively simple, but insightful analytical example illustrates the potential of this method. 相似文献
88.
Franck BA Dreschler WA Lyzenga J 《The Journal of the Acoustical Society of America》2004,116(6):3620-3628
In this study we investigated the reliability and convergence characteristics of an adaptive multidirectional pattern search procedure, relative to a nonadaptive multidirectional pattern search procedure. The procedure was designed to optimize three speech-processing strategies. These comprise noise reduction, spectral enhancement, and spectral lift. The search is based on a paired-comparison paradigm, in which subjects evaluated the listening comfort of speech-in-noise fragments. The procedural and nonprocedural factors that influence the reliability and convergence of the procedure are studied using various test conditions. The test conditions combine different tests, initial settings, background noise types, and step size configurations. Seven normal hearing subjects participated in this study. The results indicate that the reliability of the optimization strategy may benefit from the use of an adaptive step size. Decreasing the step size increases accuracy, while increasing the step size can be beneficial to create clear perceptual differences in the comparisons. The reliability also depends on starting point, stop criterion, step size constraints, background noise, algorithms used, as well as the presence of drifting cues and suboptimal settings. There appears to be a trade-off between reliability and convergence, i.e., when the step size is enlarged the reliability improves, but the convergence deteriorates. 相似文献
89.
Wouter Schuurman Peter A. Levett Michiel W. Pot Paul René van Weeren Wouter J. A. Dhert Dietmar W. Hutmacher Ferry P. W. Melchels Travis J. Klein Jos Malda 《Macromolecular bioscience》2013,13(5):551-561
Gelatin‐methacrylamide (gelMA) hydrogels are shown to support chondrocyte viability and differentiation and give wide ranging mechanical properties depending on several cross‐linking parameters. Polymer concentration, UV exposure time, and thermal gelation prior to UV exposure allow for control over hydrogel stiffness and swelling properties. GelMA solutions have a low viscosity at 37 °C, which is incompatible with most biofabrication approaches. However, incorporation of hyaluronic acid (HA) and/or co‐deposition with thermoplastics allows gelMA to be used in biofabrication processes. These attributes may allow engineered constructs to match the natural functional variations in cartilage mechanical and geometrical properties.
90.
In this paper a recently developed provably passive and stable 3D FDTD subgridding technique, based on finite elements principles, is extended to body-of-revolution (BOR) FDTD. First, a suitable choice of basis functions is presented together with the mechanism to assemble them into an overall mesh consisting of coarse and fine mesh cells. Invoking appropriate mass-lumping concepts then leads to an explicit leapfrog time stepping algorithm for the amplitudes of the basis functions. Attention is devoted to provide the reader with insight into the updating equations, in particular at a subgridding boundary. Stability, grid reflection and dispersion are also discussed. Finally, some numerical examples for toroidal and cylindrical cavities demonstrate the stability and accuracy of the method. 相似文献