共查询到19条相似文献，搜索用时 912 毫秒
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本文证明了超越方程(e~(λ_2t)-1)/(e~(λ_1t)-1)=1/R根的存在性与唯一性,并给出计算此方程的一种大范围收敛的迭代公式。 相似文献
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研究了如下的拟线性椭圆型方程:△pu+uq+λup*-1=0,u∈W1o,p(Ω), (1λ)其中,Ω2是RN中具有光滑边界的有界区域,△pu=div( |▽u|p-2▽u),N≥3,2≤p＜N,0＜q＜1,p*=NP/N-P.设λ*(Ω,p,q)是拟线性椭圆型方程(1λ)可解的参数集的上确界.运用变分方法,在不要求具有对称性质的一般区域Ω上得到了λ*(Ω,p,q)的一个可以精确计算的下界. 相似文献
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窦井波 《中国科学院研究生院学报》2008,25(1):12-19
利用变分原理研究Heisenberg群上p-次Laplace方程-△H,pu=λg(ξ)| u |γ-2u,当λ∈R,1＜p＜Q=2n-2,2≤γ＜Qp/Q-p,γ≠p时,方程至少存在一个非平凡解,并且采用Moser迭代技巧进行解的L∞估计. 相似文献
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一、导体内电流的行为 Rbecker·G·Heller和F·Sauter认为,用Max Well方程解决超导问题时,必须考虑电子的惯性,否则超导体内的电磁场为零会使MaxWell方程不确定。因此,超导电流和电场的关系不再满足欧姆定律,而满足加速度方程 A (1) (其中=m/n_se~2称为惯性项,m是电子质量,n_s是超导电子数密度)。在加速方程的基础上,F·London和H·London在MaxWell方程组内引入了附加方程。 (2) 作为超导电流所遵循的附加条件,式中λ_L为London穿透深度,由下式给出λ_L=(m/μ_0n_6e~2)~(1/2) (3) 方程(1)和(2)与MaxWel方程一起构成了超导体的宏观电动力学基础。 London方程说明了超导体中的超导电流只有在磁场存在的 相似文献
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在De Broglie假设中，对于能量—频率表达式E=hv代表粒子的总能还是动能，人们一直存在不同看法。本文提出了一个使物质波的波长和频率既满足波速公式v=vλ，又满足相对论能量—动量公式（mc^2）^2=c^2p^2＋（m0c^2）^2的能量—频率表达式；在此基础上，将定态Schroedinger方程和Klein-Gordon方程统一为一个新方程。 相似文献
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颜毅华和樱井 2 0 0 0年在太阳物理杂志上发表一文 ,他们采取引入满足一定条件的局部参数λ来替代无力因子α的方法 ,针对太阳光球外围开放空间的非常α无力场模型 ,提出了一个边界积分方程表示 .李柱恒等人在 2 0 0 4年发表于英国皇家天文学月刊的文章中 ,研究该边界积分方程的性质 ,遇到了一类重要奇异曲面积分 .为了计算这类积分 ,本文在黎曼积分理论中引入同分布概念 ,建立同分布原理 ,并给出它的某些重要应用 . 相似文献
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尚轶伦 《中国科学院研究生院学报》2012,29(1):12-16
考虑加权连通图上的简单连续时间马氏过程,每条边上赋权为马氏过程的转移速率,使得马氏过程混合时间最短的赋权问题称之为最快混合马氏过程问题(FMMP).我们证明FMMP在图自同构群的不变点集合中取到最优,并且在边传递图中解析地得到了最优解. 相似文献
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一种射频大功率放大器电源偏置电路设计方法（英文） 总被引：2，自引：0，他引：2
设计射频大功率放大器时，为了传输大的电源电流而加宽的λ/4电源偏置微带线往往不能很好的对偏置电路和信号电路进行隔离，从而影响放大器的性能。本文对一种采用加厚微带线设计λ/4电源偏置电路的方法进行了分析，并根据一种卫星数传发射机的功率放大器设计要求，分别采用本文介绍的方法和传统方法设计了两个功率放大器，给出了分析和试验结果，结果表明加厚λ/4偏置微带线可以比传统方法令功率放大器获得更高的性能，具有较大参考意义。 相似文献
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The multivariable approach to the synthesis of networks composed of a finite number of uniform lossless transmission lines, commensurable or incommensurable, and lumped passive elements is verified by showing that the multivariable rational matrix, W(λ0,λ1, .. ,λn) is bounded real in (n + 1) complex variables if and only if W is bounded real in p after substituting, λ0 = α0p + β0 and λi = tanh (αip + βi) for λi (1?i?n) where all the α's and β's are nonnegative and arbitrary, except for being not simultaneously zero in like indexed pairs. Consequences of this result are discussed. 相似文献
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通过引入参数λ,应用改进的Euler-Maclaurin求和公式,给出一个具有最佳常数因子的较为精密的Mulholland不等式,作为应用,给出了它的等价形式。 相似文献
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通过引入参数λ,应用改进的Muler-Maclaurin求和公式,给一个Hardy-Hilbert型不等式以具有最佳常数因子的推广,作为应用,给出了它的等价形式。 相似文献
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This work reports experimental and theoretical studies of hydrodynamic behaviour of deformable objects such as droplets and cells in a microchannel. Effects of mechanical properties including size and viscosity of these objects on their deformability, mobility, and induced hydrodynamic resistance are investigated. The experimental results revealed that the deformability of droplets, which is quantified in terms of deformability index (D.I.), depends on the droplet-to-channel size ratio ρ and droplet-to-medium viscosity ratio λ. Using a large set of experimental data, for the first time, we provide a mathematical formula that correlates induced hydrodynamic resistance of a single droplet ΔRd with the droplet size ρ and viscosity λ. A simple theoretical model is developed to obtain closed form expressions for droplet mobility ? and ΔRd. The predictions of the theoretical model successfully confront the experimental results in terms of the droplet mobility ? and induced hydrodynamic resistance ΔRd. Numerical simulations are carried out using volume-of-fluid model to predict droplet generation and deformation of droplets of different size ratio ρ and viscosity ratio λ, which compare well with that obtained from the experiments. In a novel effort, we performed experiments to measure the bulk induced hydrodynamic resistance ΔR of different biological cells (yeast, L6, and HEK 293). The results reveal that the bulk induced hydrodynamic resistance ΔR is related to the cell concentration and apparent viscosity of the cells. 相似文献
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The polynomial solutions of the equation fy″ + gy′ + λy = 0 are obtained and classified for f, g, and λ certain second-degree, first-degree, and zero-degree polynomials, respectively. Applications are given illustrating the use of these polynomials in the construction of amplitude functions and system functions and in tree counting. In particular, all-pole and rational filter functions are considered which include as special cases the Chebyshev, Butterworth, elliptic, Bessel, and various transitional filter functions. 相似文献
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Lawrence J. Heidt 《Journal of The Franklin Institute》1942,234(5):473-485
Direct absorption of light by glycosides dissolved in water has been discovered to produce changes in optical activities and formation of material which reduces the Shaffer, Hartmann, Somogyi reagent. Comparison of these measurements indicates in many cases the same products as are formed by hydrolysis in acid. The β glucosides and α fructoside, however, apparently give optically inactive photolytic products.Absorption spectra were obtained for α benzylfructofuranoside and β benzylfructopyranoside, and were found to be the same in the near ultraviolet as those previously obtained for benzyl glucosides and benzyl alcohol.The absorption spectrum for freshly purified fructose gives a deeper minimum about λ240 mμ than the previously reported values. The latter, however, were approached when the dry crystals had stood in air for several months although no change occurred in their sp.rot., m.p. or general apperance.All the glycosides studied were white crystalline compounds. Less than five per cent. of the ultraviolet light of λ254 mμ they absorb produces reaction; nevertheless, the apparatus and procedures available were adequate to study the reaction conveniently in monochromatic light of this wave-length.The absorption spectra, the products of photolysis, and the quantum yields, the latter based on the reducing material formed, lead to the hypothesis that the photochemical reaction is produced by an intramolecular transfer of absorbed energy from the aglycone to the hemiacetal oxygen bridge which is the reactive center. The efficiency of this transfer is, as expected, greater for benzyl than for phenylethyl glucosides but phenyl glucosides, contrariwise, are the least efficient.The structure and energy possessed by the glycoside outside the aglycone have no measurable effect on the efficiency of the photochemical reaction when followed by measuring the reducing material produced although they change up to one hundred thousand fold the rates of the thermal hydrolyses in acid. 相似文献