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991.
U. Goginava 《Acta Mathematica Hungarica》2007,115(4):333-340
The main aim of this paper is to prove that the maximal operator
of the Fejér mean of the double Walsh-Fourier series is not bounded from the Hardy space H
1/2 to the space weak-L
1/2.
This paper was written during the visit of the author at the College of Nyíregyháza in Hungary. 相似文献
992.
Behavior of concrete cylinders confined by carbon-composite tapes and prestressed yarns 1. Experimental data 总被引:1,自引:0,他引:1
V. Tamuzs R. Tepfers Chi-Sang You T. Rousakis I. Repelis V. Skruls U. Vilks 《Mechanics of Composite Materials》2006,42(1):13-32
The results of a comprehensive test program for the mechanical behavior of round concrete specimens confined by carbon-fiber
epoxy tapes and prestressed carbon yarns are reported. Five different concrete batches of compressive strength from 20 to
100 MPa and the confinement of various thickness and pretension level were investigated. The specimens, which were subjected
to monotonic or repeated compressive loadings, showed a nonlinear stress-strain behavior with a significant ductility and
increased ultimate strength, in contrary to the brittle behavior of plain concrete. The limit of linearity on the stress-strain
diagrams of the confined concrete roughly coincided with the ultimate strength of plain concrete. Above this limit, the damage
accumulation and plastic deformations proceeded in the confined specimens. This fact was evidenced by the increasing slope
of deformation diagrams in unloadings and repeated loadings and by the pronounced residual strains. The limit of linearity
could be raised significantly by pretension of the carbon yarns during their winding.
Russian translation published in Mekhanika Kompozitnykh Materialov, Vol. 42, No. 1, pp. 21–44, January–February, 2006. 相似文献
993.
We investigate the dynamics of microcapsules in linear shear flow within a reduced model with two degrees of freedom. In previous
work for steady shear flow, the dynamic phases of this model, i.e. swinging, tumbling and intermittent behaviour, have been identified using numerical methods. In this paper, we integrate
the equations of motion in the quasi-spherical limit analytically for time-constant and time-dependent shear flow using matched
asymptotic expansions. Using this method, we find analytical expressions for the mean tumbling rate in general time-dependent
shear flow. The capsule dynamics is studied in more detail when the inverse shear rate is harmonically modulated around a
constant mean value for which a dynamic phase diagram is constructed. By a judicious choice of both modulation frequency and
phase, tumbling motion can be induced even if the mean shear rate corresponds to the swinging regime. We derive expressions
for the amplitude and width of the resonance peaks as a function of the modulation frequency. 相似文献
994.
995.
A. Chaudhuri C. Andreoiu M. Brodeur T. Brunner U. Chowdhury S. Ettenauer A. T. Gallant A. Grossheim G. Gwinner R. Klawitter A. A. Kwiatkowski K. G. Leach A. Lennarz D. Lunney T. D. Macdonald R. Ringle B. E. Schultz V. V. Simon M. C. Simon J. Dilling 《Applied physics. B, Lasers and optics》2014,114(1-2):99-105
The introduction of Paul traps, in particular linear radio-frequency quadrupoles in the early 2000s, has revolutionized the use of ion traps for probing the properties of radioactive nuclides. It opened the path to trapping all available nuclides, independent of their chemical properties. We present an overview of direct mass measurements of short-lived nuclides using TITAN, a Penning trap mass spectrometer facility particularly suitable for precision measurements of ms-half-life nuclides. 相似文献
996.
V. E. Antonov O. I. Barkalov M. Calvo-Dahlborg U. Dahlborg V. F. Fedotov A. I. Harkunov 《高压研究》2013,33(3-6):261-272
Abstract Phase transformations occurring in initially amorphous Zn41 Sb59 semiconductor at pressures to 10 GPa and temperatures to 350C were studied using the measurement of electrical resistance, in situ energy dispersive X-ray diffraction and neutron diffraction on quenched high-pressure phases at ambient pressure. The studied T- P region involves the regions of reversible and irreversible crystallisation and phase transitions between the equilibrium crystalline low-pressure and high-pressure phases. 相似文献
997.
Asymmetric scaling of a square matrixA 0 is a matrix of the formXAX
–1 whereX is a nonnegative, nonsingular, diagonal matrix having the same dimension ofA. Anasymmetric scaling of a rectangular matrixB 0 is a matrix of the formXBY
–1 whereX andY are nonnegative, nonsingular, diagonal matrices having appropriate dimensions. We consider two objectives in selecting a symmetric scaling of a given matrix. The first is to select a scalingA of a given matrixA such that the maximal absolute value of the elements ofA is lesser or equal that of any other corresponding scaling ofA. The second is to select a scalingB of a given matrixB such that the maximal absolute value of ratios of nonzero elements ofB is lesser or equal that of any other corresponding scaling ofB. We also consider the problem of finding an optimal asymmetric scaling under the maximal ratio criterion (the maximal element criterion is, of course, trivial in this case). We show that these problems can be converted to parametric network problems which can be solved by corresponding algorithms.This research was supported by NSF Grant ECS-83-10213. 相似文献
998.
Magnetic metal and metal oxide nanoparticles capped with alkylamines have been synthesized and characterized by transmission
electron microscopy. X-ray diffraction, energy dispersive X-ray analysis and magnetization measurements. Core-shell Pd-Ni
particles with composition, Pd561Ni3000, (diameter ∼3.3 nm) are superparamagnetic at 5 K and organize themselves into two-dimensional crystalline arrays. Similar
arrays are obtained with Pd561Ni3000Pd1500 nanoparticles containing an additional Pd shell. Magnetic spinel particles of γ-Fe2O3, Fe3O4 and CoFe2O4 of average diameters in the 4–6 nm range coated with octylamine are all supermagnetic at room temperature and yield close-packed
disordered arrays. Relatively regular arrays are formed by dodecylaminecapped Fe3O4 nanoparticles (∼8.6 nm diameter) while well-ordered hexagonal arrays were obtained with octylamine-covered Co3O4 nanoparticles (∼4.2 nm diameter). 相似文献
999.
讨论了一维奇异P-Laplace方程{φp(u′))′ f(t,u)=0,t∈(0,1);u(0=u(1)=0存在C^1[0,1]或C[0,1]正解的一个充分必要条件.用到的方法主要有上下解方法和Schaude,不动点定理. 相似文献
1000.