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231.
232.
We construct an exact solution of the Friedmann equations with a phantom scalar matter field originating in string field theory and show the absence of the big-rip singularity. The notable features of the model are a ghost sign of the kinetic term and a special polynomial form of the effective tachyon potential. The constructed solution is stable under small fluctuations of the initial conditions and special variations of the form of the potential. __________ Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 148, No. 1, pp. 23–41, July, 2006. An erratum to this article is available at .  相似文献   
233.
本文设计了一个经济、绿色的新型方法,采用积雪草树叶提取物作为自然的还原剂,在不使用稳定剂或表面活性剂的情况下合成了MnO_2纳米粒子负载的Cu纳米颗粒(CuNPs).该合成过程环境友好,且避免使用有毒的还原剂.树叶提取物中的酚羟基将溶液中的Cu~(2+)还原为Cu NPs,后者再稳定在MnO_2 NPs表面.采用X射线衍射、透射电镜、场发射扫描电镜、能量散射谱和红外光谱对所得Cu/MnO_2纳米复合物进行了表征.结果表明,该材料可用作高活性、高效可重复使用的多相催化剂,用于室温水溶液NaBH_4存在下刚果红、罗丹明B和亚甲基蓝,以及硝基化合物,如2,4二硝基苯肼和4-硝基苯酚的催化还原.Cu/MnO_2纳米复合物的高稳定性可使其被分离出来,重复使用数次而活性无明显下降.  相似文献   
234.
In this paper, we study the time asymptotic behavior of the solution to an abstract Cauchy problem on Banach spaces without restriction on the initial data. The abstract results are then applied to the study of the time asymptotic behavior of solutions of an one-dimensional transport equation with boundary conditions in L 1-space arising in growing cell populations and originally introduced by M. Rotenberg, J. Theoret. Biol. 103 (1983), 181–199.  相似文献   
235.
In this article, we give some results on the S‐essential spectra of a linear operator defined on a Banach space. Furthermore, we apply the obtained results to determine the S‐essential spectra of an integro‐differential operator with abstract boundary conditions in the Banach space Lp([?a,a] × [?1,1]),p ≥ 1 and a > 0. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
236.
The main goal of this paper is to give a characterization of Wolf, Schechter, and Browder essential spectra of (2 × 2) matrix operator on a Banach space. Furthermore, we apply the obtained results to transport equations. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
237.
The latex of fig fruit (Ficus carica) is used in traditional medicine for the treatment of skin infections such as warts and also diseases of possible viral origin. Five extracts (methanolic, hexanic, ethyl acetate, hexane-ethyl acetate (v/v) and chloroformic) of this species were investigated in?vitro for their antiviral potential activity against herpes simplex type 1 (HSV-1), echovirus type 11 (ECV-11) and adenovirus (ADV). To evaluate the capacity of the extracts to inhibit the replication of viruses, the following assays were performed: adsorption and penetration, intracellular inhibition and virucidal activity. Observation of cytopathic effects was used to determine the antiviral action. The hexanic and hexane-ethyl acetate (v/v) extracts inhibited multiplication of viruses by tested techniques at concentrations of 78 μg mL(-1). These two extracts were possible candidates as herbal medicines for herpes virus, echovirus and adenovirus infectious diseases. All extracts had no cytotoxic effect on Vero cells at all tested concentrations.  相似文献   
238.
Bulletin of the Russian Academy of Sciences: Physics - An expression for the analytical relation between the surface energies and electronic work functions of the faces of a metallic crystal is...  相似文献   
239.
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