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171.
172.
S. A. Mohiuddine Tuncer Acar Abdullah Alotaibi 《Mathematical Methods in the Applied Sciences》2017,40(18):7749-7759
In the present paper, we construct a new sequence of Bernstein‐Kantorovich operators depending on a parameter α. The uniform convergence of the operators and rate of convergence in local and global sense in terms of first‐ and second‐order modulus of continuity are studied. Some graphs and numerical results presenting the advantages of our construction are obtained. The last section is devoted to bivariate generalization of Bernstein‐Kantorovich operators and their approximation behaviors. 相似文献
173.
Ruchi Ruchi Nurhayat Ispir P. N. Agrawal 《Mathematical Methods in the Applied Sciences》2017,40(16):5687-5706
Ren and Zeng (2013) introduced a new kind of q‐Bernstein–Schurer operators and studied some approximation properties. Acu et al. (2016) defined the Durrmeyer modification of these operators and studied the rate of convergence and statistical approximation. The purpose of this paper is to introduce a Kantorovich modification of these operators by using q‐Riemann integral and investigate the rate of convergence by means of the Lipschitz class and the Peetre's K‐functional. Next, we introduce the bivariate case of q‐Bernstein–Schurer–Kantorovich operators and study the degree of approximation with the aid of the partial modulus continuity, Lipschitz space, and the Peetre's K‐functional. Finally, we define the generalized Boolean sum operators of the q‐Bernstein–Schurer–Kantorovich type and investigate the approximation of the Bögel continuous and Bögel differentiable functions by using the mixed modulus of smoothness. Furthermore, we illustrate the convergence of the operators considered in the paper for the univariate case and the associated generalized Boolean sum operators to certain functions by means of graphics using Maple algorithms. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
174.
In this paper, we introduced a summation‐integral type modification of Szász–Mirakjan operators. Calculation of moments, density in some space, a direct result and a Voronvskaja‐type result, are obtained. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
175.
An apparatus for the measurement of liquid complex shear viscosity in the frequency range 80–2500 Hz, with the use of a torsion pendulum operating in forced oscillation, is described. The drive and detection system consists of a magnet inside the pendulum, two excitation and two measuring coils. The determination of the complex shear viscosity is based on the measurement of the resonance frequency and the damping of the torsion pendulum.The feasibility of this method is demonstrated with a number of Newtonian liquids in the viscosity range 0.3 to 60 m Pa s. Results for a viscoelastic polymer solution are presented. A comparison is made with other apparatus working in the same frequency range.
a
coil height
-
A
apparatus constant
-
B
magnetic induction
-
C
1,C
2
apparatus constants
-
d
diameter torsion rod
-
D
pendulum damping
-
E
apparatus constant
-
F
0
top frequency
-
G
shear modulus torsion rod
-
G
* =G + iG
complex shear modulus
-
h
length torsion rod
-
H
transfer function
-
i
-
I
moment of inertia
-
J
0
excitation-current amplitude
-
J
exc
excitation current
-
K
torsion spring constant
-
l
length pendulum mass
-
M
torque
-
n
number of coil turns
-
p
dipole moment
-
Q =
0/
mechanical quality
-
r
radius pendulum mass
-
R
Re {Z}
-
t
time
-
T
temperature
-
U
induction voltage
-
U
0
induction-voltage amplitude
-
x
distance
-
X
Im {Z}
-
Z = R + iX
liquid impedance
-
Z
cyl
characteristic cylindrical impedance
-
Z
pl
characteristic plane impedance
-
angle
-
M
coefficient of linear expansion of the pendulum mass
-
R
coefficient of linear expansion of the torsion rod
-
rate of shear
-
penetration depth
-
steady-state viscosity
-
s
solvent viscosity
-
angular displacement
-
0
angular-displacement amplitude
-
µ
0
=4 10–7 Vs/Am
-
density
-
phase angle
-
angular frequency
-
0
top angular frequency
-
band-width 相似文献
176.
177.
This paper contains an extensive presentation of dynamic mechanical data (complex moduli), as obtained on the melts of a series of standard polystyrenes of narrow molar mass distributions. It also shows the way of obtaining structural parameters (plateau modulus and friction factor) which are needed for an interpretation of these data in terms of simple theoretical models (Maxwell elements, Doi-Edwards model). A linear mixing rule is used for taking into account the finite width of the molar mass distributions.Dedicated to Prof. F. R. Schwarzl on the occasion of his 60th birthday 相似文献
178.
HT-7U托克马克装置的纵场线圈是由多种材料组成的具有周期性分布的大型复杂结构,线圈可视为由超导线、支撑结构和绝缘材料组成的复合材料,结构极其复杂。整个线圈工作在液氦温区。在设计阶段对其宏观等效力学性能进行数值分析计算是十分必要的,但要对整个线圈直接进行有限元分析或实验是极其困难的,主要利用均匀化方法对其进行等效处理,从而分析计算其宏观等效模量,为线圈的设计和评估提供参考依据。另外本文对均匀化方法的边界条件进行了一些改进,提出了更加合理的三维边界条件。 相似文献
179.
A recent technique, developed to measure yield stress has here also been used to determine the elastic modulus of a suspension. Temperature effects have been measured. 相似文献
180.
Ramzi Othman Robert H. Blanc Marie-Noëlle Bussac Pierre Collet Grard Gary 《Comptes Rendus Mecanique》2002,330(12):849
Dispersion and attenuation of longitudinal waves in elastic or weakly viscoelastic rods are measured by analysing the resonant frequencies present in the strain spectrum due to an unknown loading. The method takes the finite measuring time of the test into account. It is applied to an aluminium bar, in which the dispersion relation is identified very accurately at frequencies up to 60 kHz. To cite this article: R. Othman et al., C. R. Mecanique 330 (2002) 849–855. 相似文献