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排序方式: 共有86条查询结果,搜索用时 31 毫秒
71.
Multiplicity results for elliptic problems with variable exponent and nonhomogeneous Neumann conditions
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Shapour Heidarkhani Ghasem A. Afrouzi Armin Hadjian 《Mathematical Methods in the Applied Sciences》2015,38(12):2589-2599
Applying three critical point theorems, we prove the existence of at least three weak solutions for a class of differential equations with p(x)‐Laplacian and subject to small perturbations of nonhomogeneous Neumann conditions. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
72.
The goal of this paper is to study the nonexistence and multiplicity of nontrivial weak solutions for a class of nonlinear systems. The results are proved by Minimum principle and the Mountain pass theorem 相似文献
73.
Using a numerical methods based on sub–super solution, we will find positive solution for the diffusive logistic equation Δu+au-bu2=0 for xΩ, with Dirichlet boundary condition. 相似文献
74.
Microwave heating of ceramic composites 总被引:1,自引:0,他引:1
The microwave heating of a ceramic composite is modelled andanalysed. The composite consists of many small ceramic particlesembedded in a ceramic cement. The composite is assumed to bewell insulated, and each particle is assumed to be in imperfectthermal contact with the surrounding cement. Based on thesetwo assumptions an asymptotic theory exploiting the small Biotnumber and small non-dimensional contact conductance is developed.Our asymptotic theory yields a set of nonlinear partial differentialequations which govern the temperature in the composite. Theseare reduced to a set of coupled nonlinear ordinary differentialequations in which the surface area of each particle entersas a parameter. Recent experiments with such composites haveshown that the steady-state temperature of the composite isstrongly dependent upon the radii of the embedded particles.Our model captures this effect. In fact, our analysis showsthat the assumption of imperfect thermal contact between theparticles and the ceramic cement is essential for this trendto be established. 相似文献
75.
采用"grafting from"的方式在溶液聚合体系中将苯乙烯(St)接枝聚合在微米级硅胶表面,制备了接枝微粒PS/SiO2;使用新型氯甲基化试剂1,4-二氯甲氧基丁烷,对接枝的聚苯乙烯进行了氯甲基化反应,制得了接枝有氯甲基聚苯乙烯(CMPS)的接枝微粒CMPS/SiO2;使用叔胺试剂对CMPS大分子链上的苄氯基团实施了季铵化反应,最终制得了固载有季铵盐(Quaternary salt)的复合型功能微粒QPS/SiO2.用红外光谱(FTIR)与化学分析法对功能微粒QPS/SiO2的化学结构与组成进行了表征;研究了各种因素对CMPS/SiO2季铵化反应的影响规律;初步考察了QPS/SiO2对大肠杆菌的(E.coil)抗菌性能.研究结果表明,接枝微粒CMPS/SiO2的季铵化反应比较容易进行;溶剂性质、叔胺试剂的种类及温度对CMPS/SiO2的季铵化反应均有影响.使用CMPS的良溶剂和用位阻小的叔胺试剂,所得产物的季铵化度均较高.QPS/SiO2具有很强的抗菌活性.使用很小的剂量(10 g/L)、在很短的接触时间内(3 min)抗菌率即可达100%,是一种优良的水不溶抗菌材料;QPS/SiO2的季铵化度越高,其抗菌活性越高;使用碳氢链较长的三丁胺制备的QPS/SiO2,其抗菌性能明显优于使用三乙胺制备的QPS/SiO2. 相似文献
76.
Verheijen JC Deiman BA Yeheskiely E van Der Marel GA van Boom JH 《Angewandte Chemie (International ed. in English)》2000,39(2):369-372
The introduction of a urea bond linking a protected diethylenetriamine (DETA) unit and the terminal amino group of a resin-bound peptide nucleic acid (PNA) decamer gave access to a PNA - DETA adduct (shown here), which hydrolyzed the target 25-mer RNA rapidly and sequence specifically. 相似文献
77.
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79.
The vaporization behavior of boron phosphate has been studied by using Knudsen effusion mass spectrometry. The vapor over BPO(4) consists of B(2)O(3), P(4)O(10), PO(2), BPO(4) (platinum cell) and B(2)O(3), PO, PO(2), BPO(3), BPO(4) (molybdenum cell). Standard enthalpies of formation and atomization (kJ/mol) were derived for BPO(4) (g) (-1000 +/- 15 and 2863 +/- 16) and for BPO(3) (g) (-731 +/- 15 and 2347 +/- 16), respectively. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
80.
In this work we present a numerical approach for finding positive solutions of the type −Δu = λf(u) for x Ω, with Dirichlet boundary condition, where f is a superlinear function of u. We will show in which range of λ, this problem achieves multiple numerical solutions and what is the behavior of the branches of solutions. 相似文献