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991.
Summary Some results of statistical analyses on data from the Rome ionospheric station during the period 1948–1983 are shown as a
model of the normal ionosphere over Rome.
Riassunto Si presenta un modello della ionosfera normale su Roma ottenuto con l'analisi statistica dei dati provenienti dalla locale stazione ionosferica lungo il periodo 1948–1983.
Резюме Предлагается модель нормальной ионосферы на Пимом на основе статистического анализа данных, полученных в Риме на ионосферной станциqi в течение 1948–1983 г.г.相似文献
992.
Butyltins were analyzed in waters from California river and lake marinas and were detected at the part per trillion (ppt) level in most locations. The tributyltin:dibutyltin (TBT/DBT) ratios in the fresh waters were similar to those in their saline counterparts indicating like rates of degradation in the two salinity regimes. 相似文献
993.
Ahmed E. Radwan 《Il Nuovo Cimento D》1987,9(10):1233-1243
Summary The capillary instability of an annular liquid jet surrounding a solid cylinder is presented. A general dispersion equation
is derived based on the linear-perturbation technique. The instability as well as stability characteristics of that model
are identified analytically and confirmed numerically. The model is unstable only to the axisymmetric perturbation whose wavelengths
are longer than the circumference of the liquid jet, while it is stable to all other perturbations. The maximum temporal amplification
values prevailing on such a model are fairly lower than those of the full liquid jet. The thicker the solid cylinder, whether
it is regular or irregular, the larger is its stabilizing effect.
Riassunto Si presenta l’instabilità capillare di un getto anulare di liquido che circonda un cilindro solido. Si deduce un’equazione generale di dispersione basata sulla tecnica di perturbazione lineare. Le caratteristiche d’instabilità cosí come quelle di stabilità di quel modello si identificano analiticamente e sono confermate numericamente. Il modello è instabile solo rispetto alla perturbazione assisimmetrica, le cui lunghezze d’onda sono piú lunghe della circonferenza del getto di liquido, mentre è stabile rispetto a tutte le altre perturbazioni. I valori massimi dell’amplificazione temporale che prevalgono in tale modello sono molto piú bassi di quelli del pieno flusso di liquido. Piú spesso è il cilindro solido sia esso regolare o irregolare, maggiore il suo effetto stabilizzante.
Резюме Анализируется капиллярная неустойчивость кольцевой жидкой струи. окружающей твердьй цилиндр. Выводится общее дисперсионное уравнение. основанное на линейной пертурбационной технике. Неустойчивость, а также характеристики устойчивости в этой модели определяются аналитически и подтверждаются численно. Предложенная модель оказывается неустойчнвой только для осесимметричных возмушений, длины волн которых превышают окружность жидкой струи, и является устойчивой для всех других возмущений. Максимальные значения временного увеличения в такой модели оказываются довольно низкими. Стабилизирующий эффект увеличивается с толщиной твердого цилиндра.相似文献
994.
995.
YU Zu-Rong 《理论物理通讯》2001,(10)
With the help of su(2) algebra technique, a new equivalent form of the fractional Fourier transformation is given. Two examples are illustrated for their physical application in quantum optics.`` 相似文献
996.
ZHANG Lixin 《中国科学A辑(英文版)》2001,44(5)
This paper is to prove that, if a one-dimensional random wa lkcan be approximated by a Brownian motion, then the related random walk in a g eneral independent scenery can be approximated by a Brownian motion in Brownian scenery. 相似文献
997.
Solar panels and bio‐optical sensors play a significant and growing role in a number of applications that are of importance to many organizations. Many of these instruments require a high transmission of radiation into the device for it to work properly. A major issue faced is that harsh marine environments often aid in the growth or development of fouling on the coverglass used to protect the instruments. Over a period of time in an ocean environment, some plant or animal may attach itself to the coverglass, ultimately obscuring the glass and rendering the instrument useless. As such, an antifouling mechanism is needed for these instruments that is inexpensive, long‐lasting, and environment friendly. The approach discussed herein involves the use of known antifouling chemicals which have been incorporated into the polymer matrix. Polymethylmethacrylate (PMMA), bisphenol A polycarbonate (Bis A PC), and a co‐polyterephthalate (CPTE) were examined. The plaques are optically transparent and previous work has shown that, for most samples, the materials display a minimal decrease in mechanical behavior upon the addition of the algaecides. This paper will discuss the effects on the materials' optical properties when exposed to both harsh marine conditions as well as high intensity UV light. Specifically, the decrease in transmission of visible light was examined over a 6 month period of time. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
998.
采用构造相容分布与非负上鞅的方法研究任意信源随机和相对熵密度的强极限定理,并由此得出若干任意信源,m阶马氏信源,无记忆信源的随机Shannon-Mcmillan定理.将已有的关于离散信源的结果加以推广. 相似文献
999.
V. V. Elkin 《Russian Journal of Electrochemistry》2009,45(1):58-64
The electrochemical impedance of charge-transfer reaction involving the stages of adsorption and desorption of intermediate partially charged substance is analyzed theoretically in the frequency-potential plane in order to study the possibility for measuring the partial charge transfer. The simplest case of adsorption two-electron transfer, namely, the Langmuir adsorption with liner dependence of reaction rate on the coverage, is considered. It is assumed that the partial charge transfer is independent of the electrode potential. 相似文献
1000.
A. A. Abramov V. I. Ul’yanova L. F. Yukhno 《Computational Mathematics and Mathematical Physics》2009,49(3):474-481
The index of the homogeneous self-adjoint boundary value problem for the Hamiltonian systems of ordinary differential equations is introduced. It is assumed that the system has a nontrivial solution. The relationship between the index of an eigenvalue of the nonlinear eigenvalue problem and the index of the corresponding homogeneous problem is established. Properties of the index of the problem and those of the eigenvalue are examined. 相似文献