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71.
We study the relaxation limit for the Aw-Rascle system of traffic flow. For this we apply the theory of invariant regions and the compensated compactness method to get global existence of Cauchy problem for a particular Aw-Rascle system with source, where the source is the relaxation term, and we show the convergence of this solutions to the equilibrium state. 相似文献
72.
M. J. Jurado M. Gaztelumendi J. Nazabal I. Mondragon 《Journal of Polymer Science.Polymer Physics》1990,28(7):1015-1031
Static and dynamic mechanical properties, morphology, and thermal behavior of polycarbonate (PC)/plasticized cellulose acetobutyrate (CAB) blends were investigated to determine whether the plasticizer of the CAB modifies the miscibility of the blend and the mechanical properties of this essentially incompatible blend. In spite of the lack of transparency of the blends, both dynamic mechanical and thermal analysis results show the presence, at all blend compositions studied, of a single glass transition temperature which varies with the composition of the blend. Considering the ternary nature of the blends, we propose that plasticizer migration and the difficulty of discerning the presence of one or two peaks in a narrow temperature range may account for the observed behavior. Scanning electron microscopy confirms the immiscibility of the blends. The blends show large positive deviations of the tensile moduli from linearity and very low ductility. The reported tensile strength data are discussed in terms of several different equations for composites. This mechanical behavior is explained as a consequence of the migration of the plasticizer and of its subsequent antiplasticizing effect on the properties of the blend. 相似文献
73.
M. Jurado Vargas A. Fernández Timón 《Journal of Radioanalytical and Nuclear Chemistry》2012,292(2):571-577
The energy distribution of the alpha particles emitted from a source is in general complex. Only under particular circumstances,
as in the case of very thin sources measured at large distances from the detector, can the energy distribution be approximated
theoretically. In this work, we used the well-known code SRIM to simulate the interaction of alpha particles within a thin
radioactive source and within the entrance window of a typical Si semiconductor detector. We considered several thin alpha
particle sources measured at a large source-to-detector distance (small solid angle), in order to compare the distributions
obtained by simulation with those determined by the theoretical model applied to this case. The study was performed for a
variety of realistic alpha particle sources: UF4, UO2, U3O8, Gd2O3, and BaSO4, considering as alpha emitters 235U, 233U, 148Gd and 226Ra. For all these cases, we obtained the distributions due to the source and due to the entrance window of the detector, and
also the final distribution given by the convolution of these two distributions. All the energy distributions obtained by
simulation showed, in general, good agreement with the predictions given by the theoretical model, which includes corrections
for Bohr straggling. 相似文献
74.
Narváez-Rivas M Pablos F Jurado JM León-Camacho M 《Analytical and bioanalytical chemistry》2011,399(6):2115-2122
The composition of volatile components of subcutaneous fat from Iberian pig has been studied. Purge and trap gas chromatography−mass
spectrometry has been used. The composition of the volatile fraction of subcutaneous fat has been used for authentication
purposes of different types of Iberian pig fat. Three types of this product have been considered, montanera, extensive cebo and intensive cebo. With classification purposes, several pattern recognition techniques have been applied. In order to find out possible tendencies
in the sample distribution as well as the discriminant power of the variables, principal component analysis was applied as
visualisation technique. Linear discriminant analysis (LDA) and soft independent modelling by class analogy (SIMCA) were used
to obtain suitable classification models. LDA and SIMCA allowed the differentiation of three fattening diets by using the
contents in 2,2,4,6,6-pentamethyl-heptane, m-xylene, 2,4-dimethyl-heptane, 6-methyl-tridecane, 1-methoxy-2-propanol, isopropyl alcohol, o-xylene, 3-ethyl-2,2-dimethyl-oxirane, 2,6-dimethyl-undecane, 3-methyl-3-pentanol and limonene. 相似文献
75.
F. Rejmund A. Bethenod P. Napolitani J. Taieb C. Villagrasa L. Audouin P. Armbruster C. O. Bacri J. Benlliure M. Bernas B. Berthier A. Boudard E. Casajeros S. Czajkowski J. J. Connell T. Enqvist T. Faesterman J. S. George A. Junghans B. Jurado F. Hammache S. Leray R. Legrain R. A. Mewaldt J. Pereira M. V. Ricciardi K. -H. Schmidt C. Stéphan K. Sümmerer L. Tassan-Got C. Volant M. E. Wiedenbeck W. Wlazlo N. E. Yanasak 《Acta Physica Hungarica A》2002,16(1-4):85-91
The isotopic distributions of fragments produced in the spallation of uranium are strongly influenced by the fission of the excited prefragments, highly fissile nuclei. The competition between fission and evaporation around the doubly-magic nucleus Pb is discussed. The light fragments from Fe beam are produced with a strong enhancement of even-even nuclei compared to the odd-odd in the region of nuclei with equal number of neutrons and protons, N ~ Z. This staggering in the production of light fragments is not observed in the production of heavy fragments, and is in contradiction with the basis of the statistical model of deexcitation of a hot nucleus. Pairing interaction as a function of the excitation energy and as a function of the isospin of the nucleus are questioned. 相似文献
76.
Jurado B Schmitt C Schmidt KH Benlliure J Enqvist T Junghans AR Kelić A Rejmund F 《Physical review letters》2004,93(7):072501
A new experimental approach is introduced to investigate the relaxation of the nuclear deformation degrees of freedom. Highly excited fissioning systems with compact shapes and low angular momenta are produced in peripheral relativistic heavy-ion collisions. Both fission fragments are identified in atomic number. Fission cross sections and fission-fragment element distributions are determined as a function of the fissioning element. From the comparison of these new observables with a nuclear-reaction code a value for the transient time is deduced. 相似文献
77.
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80.
Six commercial programs devoted to the estimation of measurement uncertainty were compared for feasibility in order to be
applied in routine chemical analysis. The main features of each program were discussed. They were applied to two well-documented
case studies. Several screen captures were considered for illustration. 相似文献