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71.
Cover Picture: Switching of Bacterial Adhesion to a Glycosylated Surface by Reversible Reorientation of the Carbohydrate Ligand (Angew. Chem. Int. Ed. 52/2014) 下载免费PDF全文
72.
Back Cover: Co‐existence of Two Different α‐Synuclein Oligomers with Different Core Structures Determined by Hydrogen/Deuterium Exchange Mass Spectrometry (Angew. Chem. Int. Ed. 29/2014) 下载免费PDF全文
73.
Mikkel Jørgensen Prof. Henrik Grönbeck 《Angewandte Chemie (International ed. in English)》2018,57(18):5086-5089
Heterogeneous catalysts are often designed as metal nanoparticles supported on oxide surfaces. Here, the relation between particle morphology and reaction kinetics is investigated by scaling relation kinetic Monte Carlo simulations using CO oxidation over Pt nanoparticles as a model reaction. We find that different particle morphologies result in vastly different catalytic activities. The activity is strongly affected by kinetic couplings between sites, and a wide site distribution generally enhances the activity. The present study highlights the role of site‐assemblies as a concept that, in addition to isolated active sites, can be used to understand catalytic reactions over nanoparticles. 相似文献
74.
Sergey Dorofeev Klaus Thomsen 《Proceedings of the American Mathematical Society》1997,125(7):2007-2011
Let be an inclusion of -factors, the trace state of , and , the set of projections in and , respectively. We prove that the Jones index for the inclusion is
This formula is exploited to obtain continuity results for the index. In particular, we obtain a formula for the index which expresses in terms of the positions of and , in , when and are finite-dimensional -subalgebras with dense union in and , respectively.
75.
Andersen C Sharma PK Christensen MS Steffansen SI Madsen CM Nielsen P 《Organic & biomolecular chemistry》2008,6(21):3983-3988
Oligodeoxynucleotides containing the double-headed nucleoside 5'(S)-C-(2-(thymin-1-yl)ethyl)thymidine were prepared by standard solid phase synthesis. The synthetic building block for incorporating the double-headed moiety was prepared from thymidine, which was stereoselectively converted to a protected 5'(S)-C-hydroxyethyl derivative and used to alkylate the additional thymine by a Mitsunobu reaction. The oligodeoxynucleotides were studied in different nucleic acid secondary structures: duplexes, bulged duplexes, three-way junctions and artificial DNA zipper motifs. The thermal stability of these complexes was studied, demonstrating an almost uniform thermal penalty of incorporating one double-headed nucleoside moiety into a duplex or a bulged duplex, comparable to the effects of the previously reported double-headed nucleoside 5'(S)-C-(thymin-1-yl)methylthymidine. The additional base showed only very small effects when incorporated into DNA or RNA three-way junctions. The various DNA zipper arrangements indicated that extending the linker from methylene to ethylene almost completely removed the selective minor groove base-base stacking interactions observed for the methylene linker in a (-3)-zipper, whereas interactions, although somewhat smaller, were observed for the ethylene linker in a (-4)-zipper motif. 相似文献
76.
Jeppe?FockEmail author Lara?Katrina?Bogart Oliver?Posth Mikkel?Fougt?Hansen Quentin?A.?Pankhurst Cathrine?Frandsen 《Hyperfine Interactions》2016,237(1):23
The magnetite/maghemite content within iron oxide nanoparticles can be determined using the mean isomer shift (\(\overline {\delta }\)). However, accurate characterisation of the composition is limited by the uncertainty associated with \(\overline {\delta }\). We have identified four independent sources of uncertainty and developed a quantitative expression for the uncertainty budget. Sources of uncertainty are categorised as follows: that from the fitting of the Mössbauer spectrum (σ fit), that of the calibration of the α-Fe reference spectrum (σ cal), thermal corrections to the spectrum due to second order Doppler shift (SODS) (σ Δδ ) and other experimental errors (σ err). Each contribution is discussed in detail using 57Fe Mössbauer spectra obtained from an iron oxide nanoparticle system at temperatures between 16 K and 295 K on different spectrometers in two different laboratories. 相似文献
77.
Jensen MH Morris EJ Simonsen AC 《Langmuir : the ACS journal of surfaces and colloids》2007,23(15):8135-8141
A number of morphological and statistical aspects of domain formation in singly and doubly supported ternary membranes have been investigated. Such ternary membranes produce macroscopic phase separation in two fluid phases and are widely used as raft models. We find that membrane interactions with the support surface can have a critical influence on the domain shapes if measures are not taken to screen these interactions. Combined AFM and fluorescence microscopy demonstrate small (500 nm) irregular domains and incomplete formation of much larger (5 microm) round domains. These kinetically trapped structures are the result of interactions between the membrane and the support surface, and they can be effectively removed by employing doubly supported membranes under physiological salt concentrations. These decoupled supported membranes display macroscopic round domains that are easily perturbed by fluid shear flow. The system allows a quantitative characterization of domain coarsening upon being cooled into the coexistence region. We determine the domain growth exponent alpha = 0.31, which is in close agreement with the theoretical value of 1/3. Analysis of the spatial domain pattern in terms of Voronoi polygons demonstrates a close similarity to equilibrated cellular structures with a maximized configurational entropy. 相似文献
78.
C. Thomsen S. Reich H. Jantoljak I. Loa K. Syassen M. Burghard G.S. Duesberg S. Roth 《Applied Physics A: Materials Science & Processing》1999,69(3):309-312
The pressure dependence of the high-energy Raman modes in single- and multi-walled carbon nanotubes was measured in the range
0–10 GPa. We found the pressure coefficient to be linear in both materials but 25% smaller in MWNT. Given that the curvature
effects on vibrational properties of the rolled-up graphene sheets are small, we can explain this difference simply with elasticity
theory.
Received: 17 May 1999 / Accepted 18 May 1999 / Published online: 4 August 1999 相似文献
79.
80.
Lee KK Benedetti LR Jeanloz R Celliers PM Eggert JH Hicks DG Moon SJ Mackinnon A Da Silva LB Bradley DK Unites W Collins GW Henry E Koenig M Benuzzi-Mounaix A Pasley J Neely D 《The Journal of chemical physics》2006,125(1):014701
Laser-driven shock compression of samples precompressed to 1 GPa produces high-pressure-temperature conditions inducing two significant changes in the optical properties of water: the onset of opacity followed by enhanced reflectivity in the initially transparent water. The onset of reflectivity at infrared wavelengths can be interpreted as a semiconductor<-->electronic conductor transition in water, and is found at pressures above approximately 130 GPa for single-shocked samples precompressed to 1 GPa. Our results indicate that conductivity in the deep interior of "icy" giant planets is greater than realized previously because of an additional contribution from electrons. 相似文献