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211.
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A system modeling fluid motions in horizontal porous layers, uniformly heated from below and salted from above by one salt, is analyzed. The definitely boundedness of solutions (existence of absorbing sets) is proved. Necessary and sufficient conditions ensuring the linear stability of a vertical constant throughflow have been obtained via a new approach. Moreover, conditions guaranteeing the global non-linear asymptotic stability are determined. 相似文献
213.
We prove a new formula for the generating function of multitype Cayley trees counted according to their degree distribution. Using this formula we recover and extend several enumerative results about trees. In particular, we extend some results by Knuth and by Bousquet-Mélou and Chapuy about embedded trees. We also give a new proof of the multivariate Lagrange inversion formula. Our strategy for counting trees is to exploit symmetries of refined enumeration formulas: proving these symmetries is easy, and once the symmetries are proved the formulas follow effortlessly. We also adapt this strategy to recover an enumeration formula of Goulden and Jackson for cacti counted according to their degree distribution. 相似文献
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215.
Center wavelength shift of vertical cavity surface emitting laser light in arrayed waveguide gratings is verified with mathematical and experimental analysis.It is induced by the linearly increasing trend of optical power of vertical cavity surface emitting laser by bias current increase.It is retrieved effectively to the original center wavelength by simple correction method of compensation.This was done for application of vertical cavity surface emitting laser as a light source in optical line terminal of wavelength division multiplexing-passive optical network. 相似文献
216.
根据垂直扫描干涉技术结合样品折射率与密度间的依赖关系,建立了低密度SiO2泡沫微球密度的检测方法,用Lorentz-Lorenz和Gladstone-Dale公式分析了SiO2泡沫微球折射率与密度间的依赖关系。实验结果和测量误差估计表明,利用垂直扫描干涉技术并结合Gladstone-Dale分析方法,可实现对低密度SiO2泡沫微球密度的精密检测,其测量误差好于5%。 相似文献
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218.
Carolyn Furlong Marta García-Fiñana Michael Puddephat Anna Anderson Katrine Fabricius Nina Eriksen Bente Pakkenberg Neil Roberts 《Magnetic resonance imaging》2013
The Cavalieri and Vertical Sections methods of design based stereology were applied in combination with 3 tesla (i.e. 3 T) Magnetic Resonance Imaging (MRI) to estimate cortical and subcortical volume, area of the pial surface, area of the grey–white matter boundary, and thickness of the cerebral cortex. The material comprises eight human cadaveric cerebri which had been separated into sixteen cerebral hemisphere specimens prior to embedding in agar gel. The results from MRI were compared with corresponding ‘gold standard’ values subsequently obtained by application of the same methodology using physical sectioning of the specimens. 相似文献
219.
The energies of the highest-occupied molecular orbitals (HOMOs) are known to be excellent predictors of the reactivities of
biogenic hydrocarbons, such as terpenes, with reactive atmospheric oxidants including O3, OH, and NO3. Structure–Activity Relationships (SARs) have also been effectively employed in such studies and related to HOMO energies
and lowest ionization energies (ionization potentials). This study employs density function theory (DFT), at the B3LYP/6-31G**
level, to predict vertical ionization energies (IPv) for a structurally diverse group of sesquiterpenes, each of which has been reported in air samples collected in the lower
troposphere. The availability of published UV photoelectron spectra for nine sesquiterpenes permits comparison of experimental
and theoretical vertical ionization energy data. The experimental and theoretical data show a good correlation (average discrepancy ± 0.07 eV).
This enables predictions of reactivities for sesquiterpenes whose tropospheric lifetimes may last only a few hours before
their transformations into secondary organic aerosols (SOA) close to their emission sources. 相似文献
220.
Polychronis Manousopoulos Vassileios Drakopoulos Theoharis Theoharis 《Journal of Computational and Applied Mathematics》2009,233(4):1063-1082
Fractal interpolation functions are very useful in capturing data that exhibit an irregular (non-smooth) structure. Two new methods to identify the vertical scaling factors of such functions are presented. In particular, they minimize the area of the symmetric difference between the bounding volumes of the data points and their transformed images. Comparative results with existing methods are given that establish the proposed ones as attractive alternatives. In general, they outperform existing methods for both low and high compression ratios. Moreover, lower and upper bounds for the vertical scaling factors that are computed by the first method are presented. 相似文献