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61.
Toshihiro Kobayashi 《Mathematical Methods in the Applied Sciences》2004,27(18):2171-2184
In this paper low‐gain adaptive stabilization of undamped semilinear second‐order hyperbolic systems is considered in the case where the input and output operators are collocated. The linearized systems have an infinite number of poles and zeros on the imaginary axis. The adaptive stabilizer is constructed by a low‐gain adaptive velocity feedback. The closed‐loop system is governed by a non‐linear evolution equation. First, the well‐posedness of the closed‐loop system is shown. Next, an energy‐like function and a multiplier function are introduced and the exponential stability of the closed‐loop system is analysed. Some examples are given to illustrate the theory. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
62.
Changes in thin zinc-sulfide films under the action of the γ-radiation of Co60 are studied by investigating electroluminescence spectra of terbium embedded in these films as a luminescent probe. It is
shown that changes in the relation of the intensities of bands, a decrease in their halfwidth and the background component,
and simplification of the spectrum are observed in a short-wave region of the Tb radiation spectrum that corresponds to5D3→7Fj transitions. The same modification of the radiation spectrum is characteristic of ZnS films whose crystalline structure is
ordered in the course of thermal annealing at a temperature of 350°C. Based on the analysis of the data obtained it is inferred
that irradiating the ZnS films with small radiation doses of 104–105 rad leads to the ordering of their crystalline structure due to the elimination of one of the types of structural defects.
Institute of Physics of Semiconductors, National Academy of Sciences of Ukraine, 45, Nauka Ave., Kiev-28, 252650. Translated
from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 3, pp. 338–341, May–June, 1997. 相似文献
63.
Luminescence properties of anodic aluminum oxide films with organic luminophores embedded into pores
V. V. Gruzinskii A. V. Kukhto A. M. Mozalev V. F. Surganov 《Journal of Applied Spectroscopy》1997,64(4):497-502
Luminescence properties of porous anodic aluminum oxide films formed in a 0.6 M solution of citric acid and luminescence of
paraterphenyl, perylene, coumarin 7, and rhodamine 6G dyes adsorbed by the films are investigated. The nature of emitting
centers in anodic aluminum oxide is revealed. Intense photoluminescence of all tested dyes embedded into pores of anodic aluminum
oxide has been found. A redshift of fluorescence spectra of dyes adsorbed by the matrix and emergence of an additional longwave
band have been detected. Data obtained can be used in developing new thin-film luminescent coatings for future applications
in optoelectronics and molecular electronics.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No 4, pp. 483–488, July–August, 1997. 相似文献
64.
通过紫外-可见吸收光谱、压力-面积等温线、二次谐波的测量,研究了不同活性分子混合聚集体的形成对LB膜光学性质的影响。分子极性基团间的相互作用,使激发态能量及平均偶极矩发生变化,导致LB膜的光学非线性明显地增强或减弱。 相似文献
65.
Absolute total electron scattering cross sections for carbon dioxide have been measured at low electron energies using a photoelectron
source. The measurements have been carried out at 27 electron energies varying from 0.91–9.14 eV with an accuracy of ±3%.
The cross sections obtained in the present experiment have been compared with other measurements and theoretical computations. 相似文献
66.
E. Hatta H. Hosoi H. Akiyama T. Ishii K. Mukasa 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,2(3):347-349
We have observed a remarkable two-armed spiral in the collapse process of a floating monolayer at the air-water interface
by phase contrast microscopy. This demonstrates that the floating monolayer as a form of soft condensed matter reorganizes
itself due to a certain kind of macroscopic or collective behavior of molecules as it collapses. This pattern formation is
caused by the breakdown of a critical dynamical balance between the deformation of solid domain and the applied surface pressure.
The fragility as well as the flexibility of the floating monolayer can be associated with the observed pattern growth. There
are also observed interesting, periodically arranged collections of molecules in numerous collapsed regions.
Received: 8 July 1997 / Accepted: 4 November 1997 相似文献
67.
68.
69.
J.S. Tsay H.W. Chang Y.L. Chiou K.T. Huang W.Y. Chan Y.D. Yao 《Journal of magnetism and magnetic materials》2006
Influences of oxygen exposure on the magnetic properties of Co/Ge(1 1 1) ultrathin films have been investigated by surface magneto-optic Kerr effect technique. As the oxygen exposure increases on Co/Ge(1 1 1) films, their magnetic properties could be modified. As an example for 15 ML Co/Ge(1 1 1) films, the coercivity increases from 730 to 920 Oe and the remanence Kerr intensity is reduced for 500 Langmuir (L) of oxygen exposure. Corresponding compositions analyzed by Auger electron spectroscopy measurement shows that the amount of oxygen on the surface layers increases with increasing the oxygen exposure time. Oxygen distributes on the topmost layers of the film. The adsorbed oxygen influences the electronic density of states of Co and results in the changes of the magnetic properties. Besides, the appearance of O/Co/Ge interface could modify the stress anisotropy, and as a result the coercivity of ultrathin Co/Ge(1 1 1) film is enhanced. 相似文献
70.
基于阿贝尔黑格斯变量的杨-米尔斯理论的红外阿贝尔化 总被引:1,自引:0,他引:1
通过SU(2)规范场的法捷耶夫-Niemi分解给出了有效阿贝尔-黑格斯型作用量的
一个计算方法. 具体指出了该分解中所用的自然规范固定以及阿贝尔投射与杨-米尔斯理论的红外动力学之间的内在关系. 推导出了色电场的一个伦敦型方程. 相似文献