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41.
Coppage R Slocik JM Briggs BD Frenkel AI Heinz H Naik RR Knecht MR 《Journal of the American Chemical Society》2011,133(32):12346-12349
The ability to control the size, shape, composition, and activity of nanomaterials presents a formidable challenge. Peptide approaches represent new avenues to achieve such control at the synthetic level; however, the critical interactions at the bio/nano interface that direct such precision remain poorly understood. Here we present evidence to suggest that materials-directing peptides bind at specific time points during Pd nanoparticle (NP) growth, dictated by material crystallinity. As such surfaces are presented, rapid peptide binding occurs, resulting in the stabilization and size control of single-crystal NPs. Such specificity suggests that peptides could be engineered to direct the structure of nanomaterials at the atomic level, thus enhancing their activity. 相似文献
42.
43.
This paper introduces a new model of pedestrian flow, formulated within a measure-theoretic framework. It consists of a macroscopic
representation of the system via a family of measures which, pushed forward by some flow maps, provide an estimate of the
space occupancy by pedestrians at successive times. From the modeling point of view, this setting is particularly suitable
for treating nonlocal interactions among pedestrians, obstacles, and wall boundary conditions. In addition, the analysis and
numerical approximation of the resulting mathematical structures, which are the principal objectives of this work, follow
more easily than for models based on standard hyperbolic conservation laws. 相似文献
44.
Metal/superconductor/semiconductor (Ag/Hg-1212/CdSe) hetero-nanostructures have been fabricated using pulse-electrodeposition
technique and are characterized by X-ray diffraction (XRD), full-width at half-maximum (FWHM) and scanning electron microscopy
(SEM) studies. The junction capacitance of Ag/Hg-1212, Hg-1212/CdSe and Ag/Hg-1212/CdSe heterojunctions is measured in dark
and under laser irradiation at room temperature. The nature of the junction formed and built-in-junction potentials were determined.
The increase in carrier concentration across the junction due to photo-irradiation has been observed. 相似文献
45.
One of the innovative technological directions for the high-temperature superconductors has been persued by fabricating the
heteroepitaxial multilayer structures such as superconductor-semiconductor heterostructures. In the present investigation,
metal/superconductor/semiconductor (Ag/Tl-2223/CdSe) hetero-nanostructures have successfully been fabricated using dc electrodeposition
technique and were characterized by X-ray diffraction (XRD), full-width at half-maximum (FWHM) and scanning electron microscopy
(SEM) studies. The measurement of junction capacitance as a function of biasing voltage was used for the estimation of junction
built-in-potential (V
D) and to study the charge distribution in a heterojunction. The Mott-Schottky plots were measured for each junction in dark
and under the photo-irradiation. The effect of laser irradiation on C-V characteristics of hetero-nanostructure has been studied. 相似文献
46.
We have observed dHvA frequencies in several samples of stage 2 graphite-AsF5 intercalation compound. A consistent interpretation is given in terms of two nested hole surfaces located at each of the 6 corners of the 2D graphite zone. A fractional ionization f = 0.42 is obtained, consistent with spin susceptibility, with the Blinowski-Rigaux analysis of reflectivity, and with recent chemical results. 相似文献
47.
The c-axis magnetisation of pyrolytic graphite at 4.2 K has been measured in fields up to 150 kG. Contrary to the predictions of a recent calculation, graphite remains diamagnetic in the ultra-quantum region. 相似文献
48.
49.
The concentration dependence of the205Tl chemical shifts of Tl+ and of (CH3)2Tl+ ions was determined in several solvents with NO
3
–
and ClO
4
–
counterions. In general, increased ion pairing caused a low-frequency shift of the205Tl resonance, with the exceptions of (CH3)2TlNO3 inn-butylamine and TlNO3 in N,N-dimethylformamide (DMF) and in hexamethylphosphorotriamide (HMPA). In HMPA,205Tl linewidths of both Tl+ and (CH3)2Tl+ increased dramatically with dilution below 0.1M. Analysis of the data allowed ion-pair formation constants and205Tl chemical shifts for the ion-paired cation and for the free (solvated) cation to be estimated for some of the solvents. 相似文献
50.
Elizabeth M. Briggs Geoffrey W. Brown Peter M. Cairns Josef Jiricny Mohamed F. Meidine 《Magnetic resonance in chemistry : MRC》1980,13(4):306-307
31P chemical shifts in N-aryliminotriphenylphosphoranes and the corresponding N-methylated phosphonium salts are presented. They can be correlated with those theories of the bonding in phosphorus-nitrogen ylides which involve partial double bonding as a result of pπ–dπ overlap. 相似文献