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101.
Ohne ZusammenfassungDiese Arbeit wurde während eines Aufenthaltes von Schmidt in der Bundesrepublik Deutschland als Preisträger der Alexander von Humboldt-Stiftung geschrieben. 相似文献
102.
S.N. Abdulmadjid M.M. Suliyanti K.H. Kurniawan T.J. Lie M. Pardede R. Hedwig K. Kagawa M.O. Tjia 《Applied physics. B, Lasers and optics》2006,82(1):161-166
We report in this paper the results of an experimental study on hydrogen analysis of solid samples in high pressure helium
ambient gas employing the basic scheme of laser induced breakdown spectroscopy (LIBS). It is shown that the metastable excited
state of helium atom can be utilized to induce delayed excitation of the ablated hydrogen atoms, and thereby avoid the Stark
broadening effect as well as overcoming the undesirable mismatch effect, which are responsible for inefficient excitation
respectively. It is further demonstrated that for samples of high boiling-point materials such as zircaloy, successful hydrogen
analysis can be achieved by a newly introduced double excitation technique employing single laser realized in a modified configuration
of the conventional LIBS method.
PACS 51-52 相似文献
103.
In this paper we prove existence results for semilinear neutral functional differential inclusions with finite or infinite
delay in Banach spaces. Our theory makes use of analytic semigroups and fractional powers of closed operators, integrated
semigroups and cosine families.
相似文献
104.
A. P. Solov’ev M. I. Perchenko Yu. P. Sinichkin O. V. Zyuryukina 《Technical Physics》2002,47(8):996-1001
An expression for a signal at the ultrasonic frequency from a photodetector arising when diffraction waves at the cathode
mix is obtained for the case when the optical and acoustic beams are space-limited and Bragg angles are small. The alternating
current generated when the scattering medium is crossed by a focused 3-MHz ultrasonic beam and illuminated by a cw He-Ne laser
is measured. Satisfactory agreement between experimental results and those calculated from the formulas obtained indicates
that our model treating acoustooptical interaction in the medium in terms of Raman-Nath diffraction is valid. Conditions for
measuring the alternating current (which is a parameter of acoustooptical imaging) that are optimal from the viewpoint of
maximizing the signal and signal-to-noise ratio are predicted theoretically and corroborated experimentally. 相似文献
105.
The long-range sound propagation from a deep ocean to a receiving system located on the shelf is modeled. The waveguide model is constructed on the basis of the data of an acoustic-oceanographic experiment carried out in the northwestern Pacific. The sensitivity and the frequency dependence of the difference in the sound field levels at the crossing of the frontal zone on the geoacoustic characteristics of the bottom of the shelf and the continental slope are investigated. It is shown that the level difference decreases by 8.2 dB as the velocity of longitudinal waves increases by 100 m/s in the range within 1490–1820 m/s. 相似文献
106.
Results of acoustic measurements in skeletal muscle are generalized. It is shown that assessment of the pathologies and functional condition of the muscular system is possible with the use of shear waves. The velocity of these waves in muscles is much smaller than the velocity of sound; therefore, a higher symmetry type is formed for them. In the presence of a preferential direction (along muscle fibers), it is characterized by only two rather than five (as in usual media with the same anisotropy) moduli of elasticity. A covariant form of the corresponding wave equation is presented. It is shown that dissipation properties of skeletal muscles can be controlled by contracting them isometrically. Pulsed loads (shocks) and vibrations are damped differently, depending on their frequency spectrum. Characteristic frequencies on the order of tens and hundreds of hertz are attenuated due to actin-myosin bridges association/dissociation dynamics in the contracted muscle. At higher (kilohertz) frequencies, when the muscle is tensed, viscosity of the tissue increases by a factor of several tens because of the increase in friction experienced by fibrillar structures as they move relative to the surrounding liquid; the tension of the fibers changes the hydrodynamic conditions of the flow around them. Finally, at higher frequencies, the attenuation is associated with the rheological properties of biological molecules, in particular, with their conformational dynamics in the wave field. Models that describe the controlled shock dissipation mechanisms are proposed. Corresponding solutions are found, including those that allow for nonlinear effects. 相似文献
107.
O. A. Pshenitsyna 《Journal of Mathematical Sciences》2006,135(5):3384-3399
We consider the arithmetic properties of the factor-rank and term-rank functions for matrices over semirings. In particular,
we investigate the sets of matrices that satisfy the extremes of inequalities for these rank functions of matrix union. The
classification of the linear transformations that keep these sets invariant is obtained.
__________
Translated from Fundamentalnaya i Prikladnaya Matematika, Vol. 9, No. 3, pp. 175–197, 2003. 相似文献
108.
N. O. Maksimova 《Journal of Mathematical Sciences》2006,135(1):2675-2679
In the article, it is proved that any nonnegative solution of an elliptic quasilinear inequality that vanishes on a subset
of positive measure is trivial.
__________
Translated from Trudy Seminara imeni I. G. Petrovskogo, No. 25, pp. 112–118, 2005. 相似文献
109.
110.
R. Martínez-Snchez J. A. Matutes-Aquino O. Ayala-Valenzuela S. D. De la Torre 《Physica B: Condensed Matter》2002,320(1-4):285-287
An amorphous phase containing traces of non-transformed Co and Ti powders was obtained by mechanical alloying nominal compositions of Co67Ti33 and Co50Ti50 in a high-energy ball-mill. These alloys were prepared from elemental powders of Co and Ti. The heat treatment of Co67Ti33 at 573, 873 and 1173 K crystallized nanoparticles of Co2Ti and Co3Ti compounds, while the same treatments conducted on Co50Ti50 resulted in the formation of Co2Ti and CoTi nanoparticles. The saturation magnetizations reached a maximum value in the amorphous state and they decreased when the temperatures of the heat treatment rose. Demagnetizing interparticle interaction effects were estimated through hysteresis loops and initial magnetization curves using the Fourier technique. 相似文献