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1.
C-H. Chu R. V. Hü gli M. Mackey 《Proceedings of the American Mathematical Society》2004,132(11):3305-3308
Let be the Banach algebra of bounded holomorphic functions on the open unit ball of a Banach space. We show that the identity operator is an isolated point in the space of composition operators on . This answers a conjecture of Aron, Galindo and Lindström.
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We study spectral approximations of Schrödinger operators T = ?Δ+Q with complex potentials on Ω = ?d, or exterior domains Ω??d, by domain truncation. Our weak assumptions cover wide classes of potentials Q for which T has discrete spectrum, of approximating domains Ωn, and of boundary conditions on ?Ωn such as mixed Dirichlet/Robin type. In particular, Re Q need not be bounded from below and Q may be singular. We prove generalized norm resolvent convergence and spectral exactness, i.e. approximation of all eigenvalues of T by those of the truncated operators Tn without spectral pollution. Moreover, we estimate the eigenvalue convergence rate and prove convergence of pseudospectra. Numerical computations for several examples, such as complex harmonic and cubic oscillators for d = 1,2,3, illustrate our results. 相似文献
3.
The structures of the carbon sublayers in the annealed Co/C soft X-ray multilayers fabricated by using a dual-facing-target
sputtering system have been characterized by transmission electron microscopy (TEM) and Raman spectroscopy (RS). The results
suggest that the structural variations in the carbon layers can be roughly divided into three stages, i.e. ordering, crystalline
and grain growth stages. At the ordering stage with annealing temperatures below 400°C, the amorphous carbon layers change
from ones of bond-angle disorder and fourfold-bonding only to ones of threefold-bonding. At the crystalline stage, the amorphous
carbon layers in the as-deposited multilayers crystallize to graphite crystallites in the annealing temperature range of 500–600°C.
At the grain growth stage, the specimens are annealed at temperatures higher than 700°C. A growth in the graphite crystallite
dimensions is observed, which is consistent with the TEM results.
Project supported by the National Natural Science Foundation of China and Beijing Zhongguancun Associated Center of Analysis
and Measurement. 相似文献
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John L. Eves Naoise Grisewood Remo Hügli Hans-Benjamin Braun 《Journal of magnetism and magnetic materials》2010,322(9-12):1381-1384
Magnetic domain wall racetrack memory samples allow for the controlled motion of isolated magnetic domain walls in a quasi one-dimensional geometry. Here we consider the possibility of the dynamical formation of bound states of domain walls that can be prepared via a suitably chosen external field. Upon switching off the external field, these domain walls oscillate around their common center of mass, with a frequency depending on the relative initial handedness of the domain wall. Such breather states may be observed by detecting the resulting magnetization oscillations. 相似文献
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Małgorzata I. Szynkowska Aneta Węglińska Elżbieta Wojciechowska Tadeusz Paryjczak 《Chemical Papers》2009,63(2):233-238
Commercial hopcalite calcined at different temperatures and hopcalite modified with noble metals (Pt, Pd, and Au) were studied
in oxidation of thiophene. Surface and bulk properties of catalysts were studied using temperature-programmed reduction (TPRH2), X-ray diffraction method (XRD) and thermal analysis (TG-DTA-MS). It was shown that calcined samples displayed higher activity
in comparison with commercial untreated hopcalite; however, a lower temperature of calcination was favourable. High temperature
of thermal treatment induced an increase in the crystallinity and a decrease in the surface area of the samples, and, as a
consequence, the loss of catalysts activity. Moreover, marked improvement in the catalytic performance of platinum and palladium
modified catalysts in relation to base hopcalite was observed. The obtained results indicate that the higher activity of samples
containing Pt and Pd was accompanied by better reducibility of the catalysts.
Presented at the 35th International Conference of the Slovak Society of Chemical Engineering, Tatranské Matliare, 26–30 May
2008. 相似文献
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A group of non-thermal ions has been observed when 1.06 μm laser radiation is resonantly absorbed by its own self-generated plasma. The ratio between the kinetic energy carried by this ion group and the total kinetic energy of the plasma ions has been measured. From X-ray measurements indirect evidence has been found for modification of the electron energy distribution due to the acceleration of electrons in the resonant longitudinal field. The experimental results are interpreted by a simple theoretical model. 相似文献
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YC Chang P Wägli V Paeder A Homsy L Hvozdara P van der Wal J Di Francesco NF de Rooij H Peter Herzig 《Lab on a chip》2012,12(17):3020-3023
A germanium (Ge) strip waveguide on a silicon (Si) substrate is integrated with a microfluidic chip to detect cocaine in tetrachloroethylene (PCE) solutions. In the evanescent field of the waveguide, cocaine absorbs the light near 5.8 μm, which is emitted from a quantum cascade laser. This device is ideal for (bio-)chemical sensing applications. 相似文献
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用透射电子显微镜(TEM)和Raman散射(RS)研究了对向靶溅射法制备的Co/C软X射线多层膜在退火条件下碳的结构变化.结果表明,碳层的结构变化可大致分为三个阶段,即有序化,结晶以及晶粒生长阶段。在退火温度低于400℃时的有序化阶段,非晶碳层中键角无序的三配位键和四配位键转变为理想的三配位键。在结晶阶段,非晶碳层在500~600℃的退火温度下结晶成为石墨微晶。在晶粒生长阶段,样品在700℃以上温度退火,石墨微晶尺寸增大,与TEM分析结果相一致。 相似文献