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61.
The structural rules which govern the epitaxial crystallisation of polymers - and especially polyolefins - on organic substrates are established. Illustrative examples involve isotactic and syndiotactic polypropylenes and poly( l-butene). Investigation of the film structure by electron microscopy, electron diffraction and atomic force microscopy reveals some unprecedented features, including in particular the selection of the contact plane according to the chirality of its constituent helices, and direct observation of both right and left hands of polyolefin helices. 相似文献
62.
Jochen Schölhammer Brigitte Baretzky Wolfgang Gust Eric Mittemeijer Boris Straumal 《Interface Science》2001,9(1-2):43-53
The atomic force microscopy (AFM) was used to study the grain boundary (GB) groove profiles far away from the melting temperature T
m. It is shown that AFM allows one to measure the temperature dependence of the GB energy in a rather broad temperature interval (from 0.85 T
m to T
m). The GB energy and GB segregation of Bi were measured at 1123 K in the interval of the Bi bulk concentration x
v
Bi from 5 to 140 ppm Bi. The transition from monolayer to multilayer adsorption is observed for the 19a GB at 1123 K and x
v
Bi = 60 at. ppm Bi. At the same point (1123 K and x
v
Bi = 60 at. ppm Bi) a discontinuity of the first derivative of the GB energy is observed. These features were explained using the model of GB prewetting phase transformation developed previously. 相似文献
63.
Dautrey Sébastien Bodiguel Jacques Arrault Axelle Jamart-Grégoire Brigitte 《Tetrahedron》2012,68(23):4362-4367
1H NMR and FTIR experiments performed on the 1:1[α:α-N-amino]mers series let us to point out a rare NH–π interaction between the carbamidic NH of the i residue and the phenyl group of a phenylalanine residue located at i+2. 相似文献
64.
65.
M. I. Kopp A. V. Tur V. V. Yanovsky 《Journal of Experimental and Theoretical Physics》2017,124(6):1010-1022
We have found a new type of large-scale instability in a rotating stratified moist atmosphere with small-scale turbulence. The turbulence is excited by an external small-scale force with a low Reynolds number. We have constructed the theory based on the method of multiscale asymptotic expansions. The nonlinear equations for large-scale motion have been derived in the third order of the perturbation theory. We have investigated the linear instability and stationary nonlinear regimes. Solutions in the form of localized vortex structures or kinks of a new type have been obtained. 相似文献
66.
Marie-Pierre Oury Rollande Dumont Catherine Jurie Jean-François Hocquette Brigitte Picard 《BMC biochemistry》2010,11(1):12
Background
An important variability of contractile and metabolic properties between muscles has been highlighted. In the literature, the majority of studies on beef sensorial quality concerns M. longissimus thoracis. M. rectus abdominis (RA) is easy to sample without huge carcass depreciation and may appear as an alternative to M. longissimus thoracis for fast and routine physicochemical analysis. It was considered interesting to assess the muscle fibres of M. rectus abdominis in comparison with M. longissimus thoracis (LT) and M. triceps brachii (TB) on the basis of metabolic and contractile properties, area and myosin heavy chain isoforms (MyHC) proportions. Immuno-histochemical, histochemical, histological and enzymological techniques were used. This research concerned two populations of Charolais cattle: RA was compared to TB in a population of 19 steers while RA was compared to LT in a population of 153 heifers. 相似文献67.
Bibal B Tinant B Declercq JP Dutasta JP 《Chemical communications (Cambridge, England)》2002,(5):432-433
The new tetra-thiophosphonatocavitand 1 in its iiii configuration extracts quantitatively Ag+ ions from aqueous solutions; the tetranuclear complex [1(2).Ag4Pic4] was selectively formed and characterized in the solid state by X-ray diffraction which revealed the formation of a new dimeric assembly through Ag+ coordination. 相似文献
68.
D. H. Chaplin W. D. Hutchison M. P. Kopp N. Yazidjoglou 《Hyperfine Interactions》1988,43(1-4):241-247
Electric quadrupole interactions of impurity nuclei in single crystals of54MnNi,125SbNi and125SbFe have been studied as a function of crystal field direction and applied magnetic field using MAPON. Distributions are in all
cases broad compared with the mode values of the EQI's. For54MnNi the mode efg is isotropic to better than 5% between the easy <111> axis and a hard <100> axis. The efg is +0.88 (15)x 1019 Vm−2. The mode efg for125SbFe along its easy <100> axis is one half of that along a hard <112> axis, and one third of that measured along the easy <111>
axis of125SbNi. The much larger efg mode and distribution seen in125SbNi, for four to eight times greater dilution than for125SbFe, suggests intrinsic contributions due to valence screening effects in the more itinerant nickel host. 相似文献
69.
Brigitte Servatius 《Mathematische Zeitschrift》1983,184(1):133-137
70.