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971.
Tunable resonance enhanced far-infrared stimulated Raman scattering was observed in 60–160 μm range for the Q(J) transitions in hydrogen chloride. The tuning range was about 2.3 cm-1 around each studied transition (J = 2 to 7) and the photon efficiency was measured to be of the order of 12% giving peak power around 80 kW. 相似文献
972.
The interaction (modelled by a LEPS potential) of a D2 molecule with an icosahedral Ni13 cluster is mapped and analyzed in the form of equipotential contour plots. The topological features of the map correlate with the energetic and dynamical characteristics of the dissociative adsorption of the molecule on the cluster, which were extracted from quasiclassical trajectory simulations. A modification of the LEPS potential used originally is introduced. It brings the calculated reactivity of the cluster into agreement with the experimental data. 相似文献
973.
The anomalous properties of impure yttrium iron garnet are related to the susceptibilities of the rare earth ions which it contains. The susceptibilities are calculated assuming a slow relaxation. It is shown that the success of the theory of “slow relaxation” requires the existence of a coupling between the transverse magnetization of the iron lattice on the one hand, and components of the magnetic moments of the rare earth ions, with non zero diagonal matrix elements, on the other hand. The temperature variations of the ferrimagnetic linewidth and the nuclear relaxation time are compared. 相似文献
974.
A simple direct method is presented for the spectrophotometric determination of calcium in hydrochloric acid soil extracts. The chromugenic agent used is Calciehrome (self-coupled diazotized H-acid), and the method covers the range 4 to 175 μg of calcium. A comprehensive study of interferences has been carried out. and a cation-exchange procedure described for the preliminary separation of large amounts of phosphate. 相似文献
975.
François Fricker 《Archiv der Mathematik》1973,24(1):278-286
Ohne ZusammenfassungHerrn ProfessorAlexander Ostrowski zum achtzigsten Geburtstag gewidmet 相似文献
976.
G. A. Ayçik 《Journal of Radioanalytical and Nuclear Chemistry》1992,157(1):115-123
To perform quantitative analysis of Ge(Li) spectra, not only energy calibration but also efficiency calibration procedures are done. Although the use of standard sample volume, mass, density and geometry is preferable, this optimum is not always possible. So to achieve an optimization is the main objective of the work reported here. Efficiencies have to be determined as a function of energy, density, thickness, mass of sample, intensity, and source-to-detector distance. 相似文献
977.
978.
We study the 2D motion of independent point particles colliding with a periodic array of circular obstacles. The interaction between the particles and the obstacles is described by a total accommodation reflection law. Assuming that the array of scatterers has finite horizon, the density of particles is approximated by the solution of a diffusion equation in the long-time and large-scale regime. The proof relies on a multiscale asymptotics and gives the order of approximation. 相似文献
979.
Y.K. Yoḡurtçu A.J. Miller G.A. Saunders 《Journal of Physics and Chemistry of Solids》1981,42(1):49-56
The six third order elastic constants of GaP have been obtained from measurements of the effect of hydrostatic and uniaxial pressures on ultrasonic wave velocities. The valence force field model has been used to obtain the bond-bending and stretching force constants. Confirmatory evidence is added to the hypotheses that zinc blende structure crystals undergo the densification transition under pressure when (1) a modified Born stability criterion that equals about 0.2 is reached at the phase transition pressure Pt, and (2) the ratio of the second order bond-bending βt to bond-stretching αt, force constants is about 0.1. These findings suggest that a macroscopic shear takes place at the transition 相似文献
980.