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61.
Regularity of pullback attractors and random equilibrium for non-autonomous stochastic FitzHugh-Nagumo system on unbounded domains 下载免费PDF全文
This paper is concerned with the stochastic Fitzhugh-Nagumo system with non-autonomous terms as well as Wiener type multiplicative noises. By using the so-called notions of uniform absorption and uniformly pullback asymptotic compactness, the existences and upper semi-continuity of pullback attractors are proved for the generated random cocycle in $L^l(\mathbb{R}^N)\times L^2(\mathbb{R}^N)$ for any $l\in(2,p]$. The asymptotic compactness of the first component of the system in $L^p(\mathbb{R}^N)$ is proved by a new asymptotic a priori estimate technique, by which the plus or minus sign of the nonlinearity at large values is not required. Moreover, the condition on the existence of the unique random fixed point is obtained, in which case the influence of physical parameters on the attractors is analysed. 相似文献
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The methacrylate monomers bearing mesogenic group and heterocyclicazo dye have been synthesized. The monomeric dye was copolymerized with the mesogenicmonomer using a free radical initiator to produce polymers useful for nonlinear optics. Themonomers and polymers were characterized by IR, ~1H-NMR, and UV-Vis spectra. Theaverage molecular weight (M_w and M_n) of the polymers were determined by gel permeationchromatography. The thermal properties of the polymers such as thermal stability andphase transition behavior were studied by thermogravimetric analysis, differential thermalanalysis, polarizing optical microscope and X-ray diffractometer. The results demonstratethat the synthesized polymers are crystalline polymers at room temperature and no liquidcrystalline phases were observed for all of them. 相似文献
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Ni Yan Jiale Song Fengyan Wang Longwang Kan Jiahang Song Weiling Wang Wenqiang Ma Weidong Zhang Gang He 《中国化学快报》1990,30(11):1984-1988
Two highly emissive pyrenoviologen derivatives were synthesized and used to fabricate fluorescent sensors for detection of picric acid (PA) with good sensitivity and selectivity. 相似文献
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Liu Q Xu X Sang W 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2003,59(3):471-475
Infrared spectroscopy studies of 2-acetylthiophene (ACTH) in 18 different organic solvents, both polar and non-polar, were undertaken to investigate the solvent-solute interactions. The frequencies of carbonyl stretching vibration upsilon(C=O) of ACTH were correlated with the properties such as the solvent acceptor number (AN) and the linear solvation energy relationships (LSER). The solvent-induced stretching vibration frequency shifts showed a better correlation with the LSER than the AN. A six-membered ring-like hydrogen bonding structure was presented and the solvent effects of ACTH in alcohol solvents were investigated in detail. 相似文献
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Yongfeng Ren Wenqiang Xu Chenyang Xue Wendong Zhang Lina Zheng 《Journal of Raman spectroscopy : JRS》2007,38(2):250-253
Bending stress and fracture strength of micromachined structures are the parameters determining the function and life span of microelectromechanical systems (MEMS) and are also indispensable data for MEMS design. This paper reports the results of a study in which a bending stress measurement method based on electromagnetic actuation and Raman spectroscopy has been examined. In this study, an eight‐cantilever mass structure is chosen as the experimental object. The results have indicated that it can accurately measure the bending stresses and fracture strength. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
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强化采油中常用的表面活性剂石油磺酸盐在通过油层时会发生色谱分离作用,其完整性受到破坏,从而影响与原油界面的活性。采用高效液相色谱法(HPLC),通过测定磺酸盐色谱分离因子,定量地描述石油磺酸盐在岩心多也介质的色谱分离程度。应用该方法可以考察影响色谱分离因子的因素,以优化化学驱油配方的设计。该方法具有灵敏度高、可靠、用量少等特点。 相似文献