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991.
Spatio temporal dynamics of the positive column of a dc neon glow discharge is studied and investigated experimentally and theoretically. Spatio temporal analysis by means of biorthogonal decomposition method (BOD) gives insights into the mechanism of irregularity and can be employed for characterization of spatio‐ temporal complexity. In the weak nonlinear region, the wave dynamics is approximated by an amplitude equation of the Ginzburg‐Landau equation (CGLE) with complex coefficients and an additional integral term based on a fluid model. In the present work we deal with irregular spatio‐temporal data. A comparison between the numerical analysis of the experimental data and simulation results are studied. A good agreement between the dynamical behaviour for experimental space‐time data and theoretical simulation space‐time results was obtained. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
992.
Binyuan Liu Yang Li Boo‐Gyo Shin Do Yeung Yoon IL Kim Li Zhang Weidong Yan 《Journal of polymer science. Part A, Polymer chemistry》2007,45(15):3391-3399
Three novel functionalized polynorbornenes (PNB) with pendant dimethyl carboxylate group (carboxylates—acetate, propionate, and butyrate) are synthesized as a vinyl‐type with a palladium (II) catalyst in high yield. The effects of size of substitutents, molar ratio of monomer to catalyst, solvent polarity, reaction time, and temperature on the polymerization of exo‐norbornene dimethyl propionate were systematically investigated. The low molar ratio and temperature, as well as high polarity of solvent, and long reaction time, are favorable for the enhancement of the monomer conversion, especially, the solvent have an obvious effect on the catalyst activity. The resulting poly(cis‐norbornene‐exo‐2,3‐dimethyl carboxylates) (PNB‐dimethyl carboxylates) show good solubility in common organic solvent and high thermal stability up to 360 °C. The glass transition temperature was detected by DMA at 331, 324, and 318 °C for acetate, propionate, and butyrate, respectively. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3391–3399, 2007 相似文献
993.
Yu. V. Vandakurov 《Technical Physics》2003,48(3):298-302
In rotating stellar convective zones, heat transfer is shown to be associated with unbalanced azimuth forces arising in the
radially ascending (heated) or descending (cold) matter. The presence of a longitude-dependent magnetic field generates additional
azimuth forces, hence, new ways of compensating for the unbalanced forces. Generally speaking, this magnetic field is variable
but may be nearly static in layers where convective equilibrium is replaced by radiative equilibrium. The condition for the
coexistence of the static and usual fields is derived. To this end, an axisymmetric azimuth magnetic field of energy comparable
to the energy of rotation should be introduced into models under consideration. In such configurations, conditions for magnetic
field generation, as in the Sun, may appear. 相似文献
994.
Study of the viscoelastoplastic deformation of an element of a body with a three-branch loading path
Yu. N. Shevchenko R. G. Terekhov N. S. Braikovskaya S. M. Zakharov 《International Applied Mechanics》1991,27(12):1162-1167
Institute of Mechanics, Academy of Sciences of the Ukraine, Kiev. Translated from Prikladnaya Mekhanika, Vol. 27, No. 12, pp. 26–33, December, 1991. 相似文献
995.
996.
V. Yu. Venediktov 《Technical Physics》2007,52(1):126-128
The potential of the technology of reflective diffraction (holographic) optical elements intended for the EUV range is considered, and their application in projection lithography is discussed. 相似文献
997.
Yang H. C. 《显形杂志》2007,10(1):83-89
Motionless mixers have found a large range of applications, including blending, reaction, dispersion, heat transfer and mass
transfer. Understanding the mixing processes that occur in these diverse systems is essential for predicting many aspects
of practical importance. The objective of this study is to perform the experimental investigations of mixing characteristics
for three different motionless mixers. The red color dye tracer was mixed in the main stream of green hair styling gel, and
then the mixing efficiency was quantified by calculating the percentage area concentration of red color at the outlet cross
section using a digital image processing technique. In the Sulzer SMX and YHC mixer, a single element mixes the fluid nearly
in two dimensions, and three-dimensional mixing is accomplished by the next elements aligned at 90o to their former one. In
the Sulzer SMX mixer, the flow appears to be globally well mixed after 5 elements, while in the YHC and YNU mixers, it is
necessary to globally well mix more than 1 and 2 elements. 相似文献
998.
999.
Yu. A. Konyaev 《Mathematical Notes》2007,81(3-4):477-482
We present a new method (the method of unitary transformations), which differs from the existing ones, for studying the stability and the norm of solutions of regular and singularly perturbed initial-value problems for nonautonomous linear and quasilinear systems of ODE with normal and “almost normal” matrices. Our results generalize similar theorems for the corresponding systems with constant matrices. This method allows one to avoid rather cumbersome traditional analysis, including the Lyapunov function method. For special classes of singularly perturbed problems, the method provides estimates for the norms of solutions in the presence of exponential or power boundary layers; these observations enrich the collection of known results in this field. 相似文献
1000.
For a real measure with variation V(x) satisfying the estimate V(x) ≤ c 0 exp(Cx) and for the Laplace transform holomorphic in the disk {¦ -C¦ ≤ C} and having at least one pole of order m, we obtain lower bounds for the positive and negative parts of the measure V ± (x) > cx m , x > x 0. We establish lower bounds for V +- (x) on “short” intervals. Applications to number theory of the results obtained are considered. 相似文献