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91.
J. -P. Ferrier 《Inventiones Mathematicae》1973,21(4):311-317
Sans résumé 相似文献
92.
This paper deals with the use of a digital image correlation technique for the determination of the actual mechanical behaviour
of a full scale reinforced concrete beam after 25 years of service in a severe industrial environment. The objective is to
investigate the influence of the service conditions on the cracking process and the flexural behaviour of the beam. For this
purpose, one beam is removed from the existing structure before being tested in four point bending in laboratory. Displacement
fields derived from digital images captured during five loading cycles are analysed in terms of crack detection and measurement,
beam deflection and curvature. Owing to its good resolution, the method proves suitable for early crack detection and measurement.
A comparison between experimental results and theoretical values derived from Eurocode 2 design code in the serviceability
state suggests the existence of a longitudinal compressive force in the beam. A complementary analysis confirms the validity
of this hypothesis. It is concluded that the cracking and the flexural behaviour of the tested beam are significantly affected
by the existence of an initial compressive stress, which is possibly resulting from a swelling of the concrete due to long
term exposure to wet atmosphere and elevated temperature. 相似文献
93.
Ferrier M Rowe AC Guéron S Bouchiat H Texier C Montambaux G 《Physical review letters》2008,100(14):146802
We investigate weak localization in metallic networks etched in a two-dimensional electron gas between 25 and 750 mK when electron-electron (e-e) interaction is the dominant phase breaking mechanism. We show that, at the highest temperatures, the contributions arising from trajectories that wind around the rings and trajectories that do not are governed by two different length scales. This is achieved by analyzing separately the envelope and the oscillating part of the magnetoconductance. For T > or approximately 0.3 K we find L phi env proportional T(-1/3) for the envelope and L phi osc proportional, T(-1/2) for the oscillations, in agreement with the prediction for a single ring [T. Ludwig and A. D. Mirlin, Phys. Rev. B 69, 193306 (2004); 10.1103/PhysRevB.69.193306C. Texier and G. Montambaux, Phys. Rev. B 72, 115327 (2005); 10.1103/PhysRevB.72.115327C. Texier, Phys. Rev. B76, 153312 (2007)10.1103/PhysRevB.76.153312]. This is the first experimental confirmation of the geometry dependence of decoherence due to e-e interaction. 相似文献
94.
Christopher Manon 《Journal of Algebraic Combinatorics》2010,31(4):467-489
We study presentations for subalgebras of invariants of the coordinate algebras of binary symmetric models of phylogenetic
trees studied by Buczynska and Wisniewski in (J. Eur. Math. Soc. 9:609–635, 2007). These algebras arise as toric degenerations of projective coordinate rings of the moduli of weighted points on the projective
line, and projective coordinate rings of the moduli of quasiparabolic semisimple rank two bundles on the projective line. 相似文献
95.
Herbert J. Dias Manon Baguenard Eduardo J. Crevelin Vinicius Palaretti Paul J. Gates Ricardo Vessecchi Antnio E.M. Crotti 《Journal of mass spectrometry : JMS》2019,54(1):35-46
We have investigated gas‐phase fragmentation reactions of protonated benzofuran neolignans (BNs) and dihydrobenzofuran neolignans (DBNs) by accurate‐mass electrospray ionization tandem and multiple‐stage (MSn) mass spectrometry combined with thermochemical data estimated by Computational Chemistry. Most of the protonated compounds fragment into product ions B ([M + H–MeOH]+), C ([ B –MeOH]+), D ([ C –CO]+), and E ([ D –CO]+) upon collision‐induced dissociation (CID). However, we identified a series of diagnostic ions and associated them with specific structural features. In the case of compounds displaying an acetoxy group at C‐4, product ion C produces diagnostic ions K ([ C –C2H2O]+), L ([ K –CO]+), and P ([ L –CO]+). Formation of product ions H ([ D –H2O]+) and M ([ H –CO]+) is associated with the hydroxyl group at C‐3 and C‐3′, whereas product ions N ([ D –MeOH]+) and O ([ N –MeOH]+) indicate a methoxyl group at the same positions. Finally, product ions F ([ A –C2H2O]+), Q ([ A –C3H6O2]+), I ([ A –C6H6O]+), and J ([ I –MeOH]+) for DBNs and product ion G ([ B –C2H2O]+) for BNs diagnose a saturated bond between C‐7′ and C‐8′. We used these structure‐fragmentation relationships in combination with deuterium exchange experiments, MSn data, and Computational Chemistry to elucidate the gas‐phase fragmentation pathways of these compounds. These results could help to elucidate DBN and BN metabolites in in vivo and in vitro studies on the basis of electrospray ionization ESI‐CID‐MS/MS data only. 相似文献
96.
Superconducting properties of carbon nanotubes 总被引:1,自引:0,他引:1
Metallic single wall carbon nanotubes have attracted much interest as 1D quantum wires combining a low carrier density and a high mobility. It was believed for a long time that low temperature transport was exclusively dominated by the existence of unscreened Coulomb interactions leading to an insulating behavior at low temperature. However experiments have also shown evidence of superconductivity in carbon nanotubes. We distinguish two fundamentally different physical situations. When carbon nanotubes are connected to superconducting electrodes, they exhibit proximity induced superconductivity with supercurrents which strongly depend on the transmission of the electrodes. On the other hand intrinsic superconductivity was also observed in suspended ropes of carbon nanotubes and recently in doped individual tubes. These experiments indicate the presence of attractive interactions in carbon nanotubes which overcome Coulomb repulsion at low temperature, and enables investigation of superconductivity in a 1D limit never explored before. To cite this article: M. Ferrier et al., C. R. Physique 10 (2009). 相似文献
97.
Ferrier M Angers L Rowe AC Guéron S Bouchiat H Texier C Montambaux G Mailly D 《Physical review letters》2004,93(24):246804
The low temperature magnetoconductance of a large array of quantum coherent loops exhibits Altshuler-Aronov-Spivak oscillations with a periodicity corresponding to 1/2 flux quantum per loop. We show that the measurement of the harmonics content provides an accurate way to determine the electron phase-coherence length L(phi) in units of the lattice length with no adjustable parameters. We use this method to determine L(phi) in a square network realized from a 2D electron gas in a GaAs/GaAlAs heterojunction, with only a few conducting channels. The temperature dependence follows a power law T(-1/3) from 1.3 K to 25 mK with no saturation, as expected for 1D diffusive electronic motion and electron-electron scattering as the main decoherence mechanism. 相似文献
98.
99.
We have investigated the potential of affinity capillary electrophoresis (ACE) to evaluate binding constants between an anionic polydispersed polymer and four peptides. Nonlinear regression and three current linearization methods, the y-reciprocal, the x-reciprocal and the double-reciprocal, were employed for the estimation of the binding constants. The x-reciprocal and the double-reciprocal plots indicated the presence of two portions of straight lines for angiopeptin, triptorelin and the thyrotropin releasing hormone (TRH), and therefore the probable existence of a second-order interaction which causes the deviation from the 1:1 model. Peptide 1 exhibited a unique binding constant of 2.4 x 10(6)M(-1). In contrast, angiopeptin, triptorelin and TRH exhibited a K(1) of 4.0 x 10(6), 5.3 x 10(6) and 20.2 x 10(6)M(-1), respectively, and a K(2) of 0.4 x 10(6), 0.5 x 10(6) and 1.4 x 10(6)M(-1), respectively. The origin of the high scattering of the data points was further investigated. Neither the viscosity, nor the adsorption of the peptides to the capillary wall appeared to be the determining factor of data scattering. Finally, a possible adsorption of the polymer leading to the electroosmotic flow instability was supposed. 相似文献
100.
Analysis of intact heparin by capillary electrophoresis using short end injection configuration 总被引:2,自引:0,他引:2
Duchemin V Le Potier I Troubat C Ferrier D Taverna M 《Biomedical chromatography : BMC》2002,16(2):127-133
A capillary electrophoresis method for the analysis of intact heparin was developed using a phosphate buffer and a fused silica capillary. Operational parameters such as pH and concentration of the running buffer were investigated. The short end injection configuration permitted a gain on peak efficiency, on the analysis time and on the repeatability of both migration times and peak areas, through a reduction of the migration distance. Moreover, the beneficial effect of the presence of sodium chloride in the heparin sample on the peak efficiency was demonstrated and the influence of the salts on the conformation of the heparin was discussed. The optimized method (short end injection configuration, 50mM phosphate buffer pH 3, heparin sample prepared in 10 g/L NaCl solution) was validated in terms of linearity, reproducibility and specificity according to ICH requirements. 相似文献