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Guochun Wen 《分析论及其应用》2005,21(2):118-131
The present paper deals with the mixed boundary value problem for elliptic equations with degenerate rank 0. We first give the formulation of the problem and estimates of solutions of the problem, and then prove the existence of solutions of the above problem for elliptic equations by the above estimates and the method of parameter extension. We use the complex method, namely first discuss the corresponding problem for degenerate elliptic complex equations of first order, afterwards discuss the above problem for degenerate elliptic equations of second order. 相似文献
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A new method is discussed to obtain the interior solution of Einstein-Maxwell equations for a charged static sphere from a known particular solutions of a similar kind. Beginning with a charged fluid interior solution reported by Patel and Pandya [11], a new interior Reissner-Nördstrom metric is obtained using this method and physical aspects of it are extensively discussed. 相似文献
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G. F. Torres del Castillo J. A. Mondragón-Sánchez 《General Relativity and Gravitation》1998,30(3):379-387
It is shown that the Maxwell equations with sources, expressed in terms of the covariant tensor field Fijand the current density four-vector Ji, are invariant under the change of the metric gijby gij
= gij+ liljif liis a principal null direction of Fijand that an analogous result holds in the case of the massless Klein-Gordon equation if liis null and orthogonal to the gradient of the field and in the case of the null dust equations if liis parallel to the dust four-velocity. An elementary proof of the following generalization of the Xanthopoulos theorem is also given: Let (gij, Fij) be an exact solution of the Einstein-Maxwell equations and let libe a principal null direction of Fij, then (gij+ lilj, Fij) is also an exact solution of the Einstein-Maxwell equations if and only if (lilj, 0) satisfies the Einstein-Maxwell equations linearized about the background solution (gij, Fij). Furthermore, analogous theorems, where the source of the gravitational field is a massless Klein-Gordon field or null dust, are presented. 相似文献
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多氰基立方烷生成热的DFT-B3LYP和半经验MO研究 总被引:5,自引:1,他引:4
运用密度泛函理论(DFT)B3LYP方法和半经验MO(MINDO/3,MNDO,AM1和PM3)方法系统计算了全部21种多氰基立方烷的生成热,首先,在DFT-B3LYP/6-31G^*水平下通过不破裂立方烷笼状骨架(亦即选择立方烷为参考物)的等键反应设计,精确计算了9种多氰基立方烷的生成热;发现B3LYP/6-31G^*结果分别地均与上述四种半经验MO方法求得的生成热之间存在良好的线性关系(相关系数均在0.9994以上),且以AM1生成热与B3LYP/6-31G^*计算值最为接近,其次,其它12种多氰基立方烷的精确生成热借助上述线性关系通过校正对应的AM1结果而获得,多氰基立方烷的生成热很高,且随-CN基数目的增加而线性地增大,表明它们属于极具潜力的“新一低高能炸药”而具开发价值。 相似文献
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光度法工作曲线不成线性关系的情况多数是由体系存在逐级配合物所致, 为获得线性关系, 有人提出在两逐级配合物的主要等色点波长测量, 认为这样可以避免同时生成第二配合物的影响, 但没有深入的理论分析。本文通过实验与理论分析, 证明此法在多数情况下仅可改善线性关系, 但不能得到直线, 经进一步研究, 找到了这个问题的另外解决办法。 相似文献
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反应体系的势能面,对了解反应的微观过程起着重要的作用,它的特征决定了化学反应的机理.原则上,由反应体系的Schrodinger方程的解,可得到体系能量随核间距变化的函数,从而获得势能面.除少数简单反应外,几乎无法精确求得复杂反应体系的势能面.因而,除从头算法外,人们先后发展了计算势能面的一些半经验方法.对某一反应,文献中可能记载好几个势能面,因此,在分析反应或计算反应的各物理量时,应当说明所应用的是何种势能面.我们曾指出,过渡态熵的可靠性,有赖于提供过渡态参数的势能面.本文从下述基元反应 相似文献
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本文推广[1]中关于问题[Ⅰ] 的无穷多对本征值,本征函数存在性定理到p>2的情形.当p=2时,所考虑的空间是Hilbert空间,可利用相应线性算子的本征函数展开;当p>2时,我们的工作空间是Banach空间.我们利用空间L~p和其对偶空间L~p(?)上的Hausdorff-Young不等式对泛函数估值,从而证明了相应的定理. 相似文献
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