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921.
J. Urban H. Sack-Kongehl K. Weiss 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1996,36(1):73-83
Structure and reactivity with oxigen of Cu clusters in the size range of 4.5±2.5 nm created by the inert gas aggregation technique were studied by HREM. The pure Cu clusters investigated under clean conditions show the structures of MTP's with a small lattice dilatation of the (111) plane of 1.25%. For icosahedral and decahedral particles this dilatation corresponds to a splitting of the nearest neighbour distance showing two different values, i.e. dilatation of 2.2% and contraction of 2.8% for the two edges of the deformed tetrahedral subunits, respectively. Oxidation at room temperature and air pressure of 1 bar only begins after a few minutes of exposure to air, after having undergone creation of probably non-stoichiometric intermediate states in the cuprite Cu2O structure with the bulk values of the bond lengths. 相似文献
922.
Minimax estimates for functionals of solutions of wave equations with time-periodic right-hand sides
L. T. Adzhubey O. G. Nakonechy Yu. K. Pidlypenko 《Journal of Mathematical Sciences》1995,77(5):3452-3457
Minimax mean-square estimates for the velocity potential in the steady regime, as well as for the intensities of harmonic
ponts sources, are obtained from the results of inaccurate measurements of the potential. Bibliography: 4 titles.
Translated fromObchyslyuval’na ta Prykladna Matematyka, No. 77, 1993, pp 87–96. 相似文献
923.
P. G. Baranov N. G. Romanov A. Hofstaetter A. Scharmann C. Schnorr F. J. Ahlers K. Pierz 《JETP Letters》1996,64(10):754-759
Two types of excitons, localized at opposite interfaces and characterized by different magnitudes of the exchange interactions
at the same radiation energies, are simultaneously in type-II GaAs/AlAs superlattices. It is shown that the additional long-wavelength
luminescence line in superlattices grown with growth interruptions after the GaAs layers is due to the recombination of an
exciton localized at an inverted interface in regions where the quantum-well width is increased by one monolayer.
Pis’ma Zh. éksp. Teor. Fiz. 64, No. 10, 701–706 (25 November 1996) 相似文献
924.
Intensity-dependent absorption of 25 ns excimer laser pulses in common UV-window materials was investigated. By employing a calorimetric technique which provides greatly enhanced sensitivity compared to transmissive measurements, two-photon absorption coefficients were determined at intensities of 2–80 MW/cm2 and found to be in good agreement with previous measurements at 10–100 GW/cm2. Also, color-center formation in fused silica was observed. It was possible to quantify transient and cumulative effects as a function of intensity. 相似文献
925.
926.
927.
N. V. Shiran A. V. Gektin V. K. Komar I. M. Krasovitska V. V. Shlyahturov 《Radiation measurements》1995,24(4):435-437
Optical properties of pure and RE doped KMgF3 crystals were studied. Thermoluminescence curves are independent of the introduced impurity for all dopant besides europium. Emission, radiation damage and TL are found to be significantly dependent on the types of Eu-dopant added to the melt: europium fluoride or oxide. An intensive high temperature TL peak at 390°C in KMgF3(Eu2O3) may be used as a dosimetric one not only for ionizing but also for UV radiation. 相似文献
928.
A fast electrooptic modulation in a polymer waveguide using a ferroelectric liquid crystal has been proposed. In this device, the surface stabilized ferroelectric liquid crystal and the soft mode ferroelectric liquid crystal are used as an active material on the passive polymer waveguide, and electrooptic switching is realized by controlling the total reflection at the polymer waveguide-liquid crystal interface. The response time is of the order of several microseconds. The analogue electrooptic modulation in the waveguide is realized using the field induced linear molecular tilt of the electroclinic effect in the soft mode ferroelectric liquid crystal. 相似文献
929.
Ch. M. Hardalov K. D. Stefanov D. Sueva 《Applied Physics A: Materials Science & Processing》1995,61(2):107-109
Deep-Level Transient Spectroscopy (DLTS) measurements were carried out on silicon p+nn+ diodes before and after irradiation with fast neutrons at room temperature with fluences 5.5×1011 and 1.0×1012 n/cm2. It was found out, that all preexisting defects decreased their amplitudes during irradiation, while only one defect, identified as a single-charged divacancy, increased in amplitude. An interpretation is proposed in terms of the cluster model, and the applicability of the DLTS is discussed. 相似文献
930.