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941.
落球法测液体粘度实验的改进 总被引:12,自引:0,他引:12
采用光电计时装置,对落球法测定液体粘度实验作了改进,减少了由手控计时引起的误差,提高了实验的准确度,扩大了测量范围. 相似文献
942.
概率论中有关计算公式的改进 总被引:5,自引:0,他引:5
通过对概率论中有关公式的研究 ,给出了全条件概率公式和二维随机变量函数的密度函数的简化计算公式 ,为其计算提供了新的方法 相似文献
943.
得到了一个解调和方程在球上的一类Dirichlet问题的简单方法,即不通过Poisson公式而实际上只解一个Euler方程,从而较容易地求出其解. 相似文献
944.
Jorge M. V. Capela Marisa V. Capela Clóvis A. Ribeiro 《Journal of mathematical chemistry》2009,45(3):769-775
The aim of this work is to find approaches for the Arrhenius integral by using the n-th convergent of the Jacobi fractions. The n-th convergent is a rational function whose numerator and denominator are polynomials which can be easily computed from three-term
recurrence relations. It is noticed that such approaches are equivalent to the one established by the Gauss quadrature formula
and it can be seen that the coefficients in the quadrature formula can be given as a function of the coefficients in the recurrence
relations. An analysis of the relative error percentages in the approximations is also presented. 相似文献
945.
946.
Observation of Newton black film (NBF) in foam film is possible only with a certain probability W which depends on the concentration C of surfactant in the solution and on the time ta during which adsorption of surfactant at the solution/air interface has taken place. In the paper, the W(C,ta) dependence is derived and used to analyze the effect of ta on the critical surfactant concentration Cc below which NBF in foam film practically cannot be observed. An expression for the Cc(ta) function is obtained which reveals that Cc decreases substantially with increasing ta. This expression is found to describe well experimental Cc(ta) data for foam films obtained from aqueous solution of the therapeutic surfactant INFASURF. 相似文献
947.
Qunchao Fan Weiguo Sun Hao Feng 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2009,74(4):911-916
A parameter-free analytical formula for dissociation energies of diatomic molecules is proposed by Fan and Sun (2009) [20] based on LeRoy and Bernstein's vibrational energy expression near dissociation limit. Using three highest vibrational energies which may be generated by the algebraic method (AM) presented in our previous study and by some other physical methods, the new formula is applied to study the molecular dissociation energies of 10 electronic states of KH, 7LiD, 7LiH, 6LiH, NaK, NaLI and NaRb heteronuclear diatomic molecules which have regular (Morse-like) potentials in this work. The results show that the AM energies and dissociation energies have excellent agreement with experimental values. 相似文献
948.
Balasubramanian Sury 《Rendiconti del Circolo Matematico di Palermo》2009,58(1):99-108
We apply group actions to some natural situations like the natural ‘linear’ action of GL
r
(Z
n
) and some of its subgroups to derive number-theoretic identities like
.
相似文献
949.
The Nevalinna–Pick algorithm yields a continued fraction expansion of every Schur function, whose approximants are identified.
These approximants are quotients of rational functions which can be understood as the rational analogs of the Wall polynomials.
The properties of these Wall rational functions and the corresponding approximants permit us to obtain a Khrushchev’s formula
for orthogonal rational functions. An introduction to the convergence of the Wall approximants in the indeterminate case is
presented.
This work was partially realized during two stays of the second author at the Norwegian University of Science and Technology
(NTNU) financed respectively by Secretaría de Estado de Universidades e Investigación from the Ministry of Education and Science
of Spain and by the Department of Mathematical Sciences of NTNU. The work of the second author was also partially supported
by the Spanish grants from the Ministry of Education and Science, project code MTM2005-08648-C02-01, and the Ministry of Science
and Innovation, project code MTM2008-06689-C02-01, and by Project E-64 of Diputación General de Aragón (Spain). 相似文献
950.
Let p∈(0,1] and s≥[n(1/p−1)], where [n(1/p−1)] denotes the maximal integer no more than n(1/p−1). In this paper, the authors prove that a linear operator T extends to a bounded linear operator from the Hardy space H
p
(ℝ
n
) to some quasi-Banach space ℬ if and only if T maps all (p,2,s)-atoms into uniformly bounded elements of ℬ.
相似文献