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991.
Herrejón-Escutia Martín Solorio-Díaz Gildardo Vergara-Hernández Héctor Javier López-Martínez Edgar Vázquez-Gómez Octavio 《Journal of Thermal Analysis and Calorimetry》2019,137(2):399-410
Journal of Thermal Analysis and Calorimetry - A model was developed to predict the formation of austenite and dilatometric behavior during continuous heating in AISI 1045 steel, which has an... 相似文献
992.
Bartomeu Galmés Daniel Martínez Maria F. Infante-Carrió Dr. Antonio Franconetti Prof. Dr. Antonio Frontera 《Chemphyschem》2019,20(9):1135-1144
This article analyzes the interplay between nitro's π-hole and halogen–bonding (XB) interactions in nitroarenes. Remarkable cooperativity effects are observed when π–hole and XB interactions coexist in the same complex. The nitroarene presents two π-holes, one approximately over the N atom of the nitro group and the other over the aromatic ring, being the former more positive. The interplay between both interactions has been analyzed in terms of energetic and geometric features of the complexes, which are computed at the RI-MP2/def2-TZVPD level of theory. Molecular electrostatic potential (MEP) surface calculations have been used to explore the variation of the MEP values at the π-hole upon the formation of halogen bonding interactions between the nitroarene and CF3X (X=Cl, Br and I) molecules. In addition, the Bader's theory of atoms in molecules” (AIM) is used to characterize the interactions by means of the distribution of bond critical points and bond paths and to analyze their strengthening or weakening depending upon the variation of charge density at critical points. The aforementioned computational methods are adequate to examine how these interactions mutually influence each other. Natural bond orbital (NBO) and noncovalent interaction plot (NCIPlot) computational tools have been also used in some representative complexes to further analyze cooperativity effects. Finally, the Cambridge Structural Database (CSD) is used to provide some experimental evidence. 相似文献
993.
Alén B Fuster D Muñoz-Matutano G Martínez-Pastor J González Y Canet-Ferrer J González L 《Physical review letters》2008,101(6):067405
We study the metal-insulator transition in individual self-assembled quantum wires and report optical evidence of metallic liquid condensation at low temperatures. First, we observe that the temperature and power dependence of the single nanowire photoluminescence follow the evolution expected for an electron-hole liquid in one dimension. Second, we find novel spectral features that suggest that in this situation the expanding liquid condensate compresses the exciton gas in real space. Finally, we estimate the critical density and critical temperature of the phase transition diagram at n{c} approximately 1 x 10;{5} cm;{-1} and T{c} approximately 35 K, respectively. 相似文献
994.
Rentenier A Ruiz LF Díaz-Tendero S Zarour B Moretto-Capelle P Bordenave-Montesquieu D Bordenave-Montesquieu A Hervieux PA Alcamí M Politis MF Hanssen J Martín F 《Physical review letters》2008,100(18):183401
We have determined absolute charge transfer and fragmentation cross sections in He2++C60 collisions in the impact-energy range 0.1-250 keV by using a combined experimental and theoretical approach. We have found that the cross sections for the formation of He+ and He0 are comparable in magnitude, which cannot be explained by the sole contribution of pure single and double electron capture but also by contribution of transfer-ionization processes that are important even at low impact energies. The results show that multifragmentation is important only at impact energies larger than 40 keV; at lower energies, sequential C2 evaporation is the dominant process. 相似文献
995.
Horner DA Miyabe S Rescigno TN McCurdy CW Morales F Martín F 《Physical review letters》2008,101(18):183002
Recent experiments on double photoionization of H2 with photon energies between 160 and 240 eV have revealed body-frame angular distributions that suggest classical two-slit interference effects may be present when one electron carries most of the available energy and the second electron is not observed. We report precise quantum mechanical calculations that reproduce the experimental findings. They reveal that the interpretation in terms of classical diffraction is only appropriate at substantially higher photon energies. At the energies considered in the experiment we offer an alternative explanation based on the mixing of two nondiffractive contributions by circularly polarized light. 相似文献
996.
In this work, erythrocytes from carp were used as a nucleated cell model to test the hypothesis that the phthalocyanines (zinc - ZnPc and chloroaluminium -AlClPc) enhance ultrasonically induced damage in vitro. In order to confirm and complete our earlier investigation, the influence of ultrasound (US) and phthalocyanines (Pcs) on unresearched cellular components, was studied. Red blood cells were exposed to 1 MHz continuous ultrasound wave (0.61 and/or 2.44 W/cm2) in the presence or absence of phthalocyanines (3 μM). To identify target cell damage, we studied hemolysis, membrane fluidity and morphology of erythrocytes. To demonstrate the changes in the fluidity of plasma membrane we used the spectrofluorimetric methods using two fluorescence probes: 1-[4-(trimethylamino)phenyl]-6-phenyl-1,3,5,-hexatriene (TMA-DPH) and 1,6-diphenyl-1,3,5-hexatriene (DPH). The effect of US and Pcs on nucleated erythrocytes morphology was estimated on the basis of microscopic observation.The enhancement of ultrasonically induced membrane damage by both phthalocyanines was observed in case of hemolysis, and membrane surface fluidity, in comparison to ultrasound. The authors also observed changes in the morphology of erythrocytes. The obtained results support the hypothesis that the Pcs enhance ultrasonically induced cell damage in vitro.Furthermore, the influence of ultrasound on phthalocyanines (Pcs) in medium and in cells was tested. The authors observed changes in the phthalocyanines absorption spectra in the medium and the increase in the intensity of phthalocyanines fluorescence in the cells. These data can suggest changes in the structure of phthalocyanines after ultrasound action. 相似文献
997.
E. Martínez J. Marian M.H. Kalos J.M. Perlado 《Journal of computational physics》2008,227(8):3804-3823
A novel parallel kinetic Monte Carlo (kMC) algorithm formulated on the basis of perfect time synchronicity is presented. The algorithm is intended as a generalization of the standard n-fold kMC method, and is trivially implemented in parallel architectures. In its present form, the algorithm is not rigorous in the sense that boundary conflicts are ignored. We demonstrate, however, that, in their absence, or if they were correctly accounted for, our algorithm solves the same master equation as the serial method. We test the validity and parallel performance of the method by solving several pure diffusion problems (i.e. with no particle interactions) with known analytical solution. We also study diffusion-reaction systems with known asymptotic behavior and find that, for large systems with interaction radii smaller than the typical diffusion length, boundary conflicts are negligible and do not affect the global kinetic evolution, which is seen to agree with the expected analytical behavior. Our method is a controlled approximation in the sense that the error incurred by ignoring boundary conflicts can be quantified intrinsically, during the course of a simulation, and decreased arbitrarily (controlled) by modifying a few problem-dependent simulation parameters. 相似文献
998.
We study the two meson-one baryon systems by solving Faddeev equations, using chiral dynamics. The calculations, carried out for the $\pi \overline{K} N$ system and its coupled channels for the case of strangeness = ?1, in the S-wave, lead to a dynamical generation of many strangeness = ?1 resonances in the 1500–1800?MeV region. While building the formalism, we found important cancellations between different sources of three-body forces. 相似文献
999.
Jesús Alvarez Marien Lopez-Arias Rebeca de Nalda Margarita Martín 《Applied Physics A: Materials Science & Processing》2008,92(4):831-836
The neutral species present in CdS ablation plumes upon nanosecond 532 nm laser irradiation at a moderate fluence of 0.5–0.75 J cm−2 have been studied. Neutral Cd
n
S
m
clusters have been identified, some as large as (CdS)33−34 (1–2 nm in diameter). The analysis of the dynamics of neutral species shows an expansion with two components that differ
both in composition and dynamics. A fast, high kinetic energy component, dominated by S2 which acquires free-flow conditions at short distances from the target, is followed by a slower component characterized by
similar speeds for all species. This slower component shows dynamic features that are expected to favor aggregation processes
leading to effective cluster formation. 相似文献
1000.
S. González-Pérez I. R. Martín F. Lahoz P. Haro-González J. Herreros 《Applied Physics A: Materials Science & Processing》2008,93(4):983-986
Local crystalline formation in erbium doped oxyfluoride glass has been obtained under a cw Argon laser irradiation up to 1.8
W pumping power. By exciting at 514 nm, the emission from 800 nm and 850 nm corresponding to the 4S3/2(2H11/2)→4I13/2 electronic transitions have been analyzed both inside and outside the irradiated area. The changes in the emission spectra
indicate that the high power Ar laser irradiation has resulted in a localized desvitrification process. The temperature dependence
of the fluorescence intensity ratio of the 800 nm and 850 nm emission bands has been used to determine the temperature of
the irradiated zone. Moreover, the average lifetime of the 4S3/2(2H11/2) thermalized levels have been measured as a function of the excitation spot position. An important decrease is observed at
the irradiated area. These results confirm that a localized cristalline phase has been created by the laser action. 相似文献