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21.
阎格 《新疆大学学报(理工版)》1993,10(4):34-41
对Fujita类方程组解的整体存在性和如何在有限时间内发生Blow up现象的研究,具有实际意义.M.Escobedo等人对其二元情形曾做过研究,即在[1]中对非线性项单一如v~(?)或u~(?)的Cauchy问题进行了讨论,本文意在上述基础上作些推广:修改非线性项如u~(?)v~(?)或u~qv~n情形,利用上、下解的方法,证明了在一定条件下,推广后的Cauchy问题亦有[1]中指出的类似的结果. 相似文献
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Nakao Hayashi Elena I. Kaikina Pavel I. Naumkin 《Mathematical Methods in the Applied Sciences》2005,28(3):275-308
We study the Cauchy problem for non‐linear dissipative evolution equations (1) where ?? is the linear pseudodifferential operator and the non‐linearity is a quadratic pseudodifferential operator (2) û ≡ ?<sub>x→ξsub> u is the Fourier transformation. We consider non‐convective type non‐linearity, that is we suppose that a(t,0,y) ≠ 0. Let the initial data , are sufficiently small and have a non‐zero total mass , where is the weighted Sobolev space. Then we give the main term of the large time asymptotics of solutions in the sub critical case. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
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We study the sub‐Riemannian geometry on the Engel group which is a step 3 nilpotent Lie group on . Our main result is to solve the Hamiltonian equations associated with the bi‐characteristic curves and express the solutions in terms of elliptic functions. Our model covers both the Heisenberg group and the Martinet case when setting certain parameters to be zero. 相似文献
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Sergei G. Kruglik Jean‐Christophe Lambry Jean‐Louis Martin Marten H. Vos Michel Negrerie 《Journal of Raman spectroscopy : JRS》2011,42(3):265-275
We describe a pump–probe Raman spectrometer based on a femtosecond Ti:sapphire laser, an optical parametric generator and two optical parametric amplifiers for time‐resolved studies, with emphasis on the structural dynamics in heme proteins. The system provides a 100‐fs pump pulse tunable in the range 500–600 nm and a transform‐limited sub‐picosecond probe pulse tunable in the range 390–450 nm. The spectrometer has spectral (25 cm−1) and temporal (∼0.7 ps) resolutions which constitute an effective compromise for identifying transient heme protein species and for following their structural evolution by spontaneous Raman scattering in the time range 0.5 ps to 2 ns. This apparatus was applied to time‐resolved studies of a broad range of heme proteins, monitoring the primary dynamics of photoinduced heme coordination state and structural changes, its interaction with protein side‐chains and diatomic gaseous ligands, as well as heme vibrational cooling. The treatment of transient Raman spectra is described in detail, and the advantages and shortcomings of spontaneous resonance Raman spectroscopy for ultrafast heme proteins studies are discussed. We demonstrate the efficiency of the constructed spectrometer by measuring Raman spectra in the sub‐picosecond and picosecond time ranges for the oxygen‐storage heme protein myoglobin and for the oxygen‐sensor heme protein FixLH in interaction with the diatomic gaseous ligands CO, NO, and O<sub>2sub>. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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Owing to its high safe, high rate and long life characteristics, lithium titanate (Li4Ti5O12) anode material has attracted extensive attention in recent years, and many efforts are being made to develop the Li4Ti5O12based high performance hybrid supercapacitors and Li-ion batteries. Herein, we prepared the organic cathode material polytriphenylamine (PTPAn) through chemical oxidation and polymerization of triphenylamine (TPAn), and investigated its charge storage mechanism and electrode kinetics with the typical electrochemical methods in an organic electrolyte. It was demonstrated that the PTPAn exhibited the reversible capacity of 85 mA·g-1. The charge storage depended on the reversible adsorption/desorption of anion, which is not controlled by the diffusion process, and thus, can be considered as the pseudocapacitive behavior. Then, the PTPAn cathode was coupled with the Li4Ti5O12anode to form a hybrid capacitor/battery system with high power and improved energy density. Finally, the inherent drawback and the challenge for practical application of such an organic cathode are briefly discussed. © Journal of Electrochemistry 2018. 相似文献