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991.
The bending problem of a magnetic film-nonmagnetic substrate cantilever system is studied by using the principle of energy
minimization. Emphasis is placed on the analysis of geometrical and physical parameter dependence of the neutral plane, internal
film stress and strain of the cantilever system, and then the influence of such a parameter on the bending characteristic
is presented. The results indicate, owing to the anisotropic expanding feature of the magnetostriction, that the neutral plane
is generally anisotropic, and moves downwards rapidly with the increasing thickness ratio. Meanwhile, the bounding rigidity
of substrate on the film will decrease with the increasing thickness ratio, and thus release the film stress, i.e., it decreases,
but the film strain increases. The effect of Poisson’s ratio of the materials on the film strain, the stress and the neutral
plane in the direction transverse to the magnetization is prominent. For the strain and the stress in the magnetization, however,
the role of Poisson’s ratio is inconspicuous. This property is due to the initiative elongating (or contracting) feature of
the magnetic film along its magnetization.
Supported by the National Natural Science Foundation of China (Grant No. 10762001), the Key Project of the Chinese Ministry
of Education (Grant No. 206024), and the Program for New Century Excellent Talents in University of China (Grant No. NCET-2005-0272) 相似文献
992.
Burkhard Kleihaus Jutta Kunz Francisco Navarro-Lérida Ulrike Neemann 《General Relativity and Gravitation》2008,40(6):1279-1310
We consider globally regular and black hole solutions in SU(2) Einstein–Yang–Mills–Higgs theory, coupled to a dilaton field.
The basic solutions represent magnetic monopoles, monopole–antimonopole systems or black holes with monopole or dipole hair.
When the globally regular solutions carry additionally electric charge, an angular momentum density results, except in the
simplest spherically symmetric case. We evaluate the global charges of the solutions and their effective action, and analyze
their dependence on the gravitational coupling strength. We show, that in the presence of a dilaton field, the black hole
solutions satisfy a generalized Smarr type mass formula.
B. Kleihaus gratefully acknowledges support by the German Aerospace Center.
F. Navarro-Lérida gratefully acknowledges support by the Ministerio de Educación y Ciencia under grant EX2005-0078. 相似文献
993.
Geocenter motion (GCM) is one important topic for constructing and maintaining the terrestrial reference frame and its applications.
GCM is studied from CHAMP with the multi-step approach in this paper. Geometric orbits of CHAMP in 2001–2006 are precisely
determined with the kinematic method only from the satellite-borne GPS zero-difference data. Then a GCM time series is estimated
from the precise kinematic orbits based on the theory of satellite dynamics to fit the CHAMP’s real geometric orbits. We compare
the series with the geocenter series used in ITRF2005. Then the GCM series are analyzed with Fourier transform and wavelet
transformation. The mean motions within 6 years in TX, TY and TZ directions are respectively 0.8 mm, 2.2 mm, and 7.9 mm. The trends of GCM in the three directions are 0.495 mm/a, −0.004
mm/a, and 1.309 mm/a, respectively. The long-term movement (2001–2006) indicates that the crustal figure is changing. The
seasonal variations are the main component which may be excitated by the mass redistribution of Earth’s fluid layer, e.g.
ocean, atmosphere and continental water. The inter-annual variations are also found in the GCM series measured with CHAMP.
Supported by the International S&T Cooperation Program of China (Grant No. 2006DFA21980), the National Hi-tech R&D Program
of China (Grant No. 2006AA12z303), the National Natural Science Foundation of China (Grant No. 40774009), and the Natural
Science Foundation of Shandong Province, China (Grant No. Y2003E01) 相似文献
994.
Leitão JM Esteves da Silva JC Girón AJ Muñoz de la Peña A 《Journal of fluorescence》2008,18(6):1065-1076
Excitation emission fluorescence matrices (EEMs) of Verapamil drug were obtained by direct and by derivatization fluorescence
spectroscopy. The fluorescence excitation and emission wavelengths were displaced to longer wavelengths and the fluorescence
intensity was enhanced upon derivation with respect to the native fluorescence of the drug. The complete EEM of the native
fluorescence of the drug and of the derivatization product were rapidly acquired by using a charged-coupled device detector
(CCD), which is advantageous in terms of speed in the analysis, with respect to the use of a conventional photomultiplier
detector. The EEMs were analyzed by several second-order multivariate calibration methods exploiting the second order advantage.
The three-dimensional decomposition methods used, based in different assumptions about the trilinearity of the three way data
structure under analysis, were parallel factor analysis (PARAFAC), bilinear least squares (BLLS), parallel factor analysis
2 (PARAFAC2) and multivariate curve resolution—alternating least squares (MCR-ALS). The determination was performed by using
the standard addition approach. The figures of merit of the PARAFAC and BLLS methods were calculated, obtaining a lower limit
of detection with the derivatization procedure, when compared with the direct measurement of the fluorescence of the drug.
In Verapamil drug the best estimations were found with the BLLS and the MCR-ALS models. In the quantification of Verapamil
in a pharmaceutical formulation the best estimation, when compared with the result obtained by the US Pharmacopeia high performance
liquid chromatography approach, was obtained by direct fluorescence spectroscopy with MCR-ALS and by derivatization fluorescence
spectroscopy with the PARAFAC2 model. 相似文献
995.
We have quantized a flat cosmological model in the context of the metric models, using the causal Bohmian quantum theory. The equations are solved and then we have obtained how the quantum corrections
influence the classical equations. 相似文献
996.
Vimla Vyas 《Pramana》2008,70(4):731-738
Speeds of sound and densities of three ternary liquid systems namely, toluene + n-heptane + n-hexane (I), cyclohexane + n-heptane + n-hexane (II) and n-hexane + n-heptane + n-decane (III) have been measured as a function of the composition at 298.15 K at atmospheric pressure. The experimental isothermal
compressibility has been evaluated from measured values of speeds of sound and density. The isothermal compressibility of
these mixtures has also been computed theoretically using different models for hard sphere equations of state and Flory’s
statistical theory. Computed values of isothermal compressibility have been compared with experimental findings. A satisfactory
agreement has been observed. The superiority of Flory’s statistical theory has been established quite reasonably over hard
sphere models.
相似文献
997.
The phase diagram of the coupled sine circle map system exhibits a variety of interesting phenomena including spreading regions
with spatiotemporal intermittency, non-spreading regions with spatial intermittency, and coherent structures termed solitons.
A spreading to non-spreading transition is seen in the system. A cellular automaton version of the coupled system maps the
spreading to non-spreading transition to a transition from a probabilistic to a deterministic cellular automaton. The solitonic
sector of the system shows spatiotemporal intermittency with soliton creation, propagation and absorption. A probabilistic
cellular automaton mapping is set up for this sector which can identify each one of these phenomena.
相似文献
998.
Note on Generalized Quantum Gates and Quantum Operations 总被引:1,自引:0,他引:1
Yue-Qing Wang Hong-Ke Du Yan-Ni Dou 《International Journal of Theoretical Physics》2008,47(9):2268-2278
Recently, Gudder proved that the set of all generalized quantum gates coincides the set of all contractions in a finite-dimensional
Hilbert space (S. Gudder, Int. J. Theor. Phys. 47:268–279, 2008). In this note, we proved that the set of all generalized
quantum gates is a proper subset of the set of all contractions on an infinite dimensional separable Hilbert space ℋ. Meanwhile,
we proved that the quantum operation deduced by an isometry is an extreme point of the set of all quantum operations on ℋ.
This subject is supported by NSF of China (10571113). 相似文献
999.
G. A. Martínez-Castañón N. Niño-Martínez F. Martínez-Gutierrez J. R. Martínez-Mendoza Facundo Ruiz 《Journal of nanoparticle research》2008,10(8):1343-1348
Silver nanoparticles with different sizes (7, 29, and 89 nm mean values) were synthesized using gallic acid in an aqueous
chemical reduction method. The nanoparticles were characterized using transmission electron microscopy (TEM), dynamic light
scattering (DLS), X-ray diffraction (XRD), and ultraviolet–visible (UV–Vis) absorption spectroscopy; the antibacterial activity
was assessed using the standard microdilution method, determining the minimum inhibitory concentration (MIC) according to
the National Committee for Clinical Laboratory Standards. From the microscopies studies (TEM) we observed that silver nanoparticles
have spherical (7 and 29 nm) and pseudospherical shape (89 nm) with a narrow size distribution. The sizes of the silver nanoparticles
were controlled by varying some experimental conditions. It was found that the antibacterial activity of the nanoparticles
varies when their size diminishes. 相似文献
1000.
Bruno Galvan 《Journal of statistical physics》2008,131(6):1155-1167
An extension of the Born rule, the quantum typicality rule, has recently been proposed [B. Galvan in Found. Phys. 37:1540–1562 (2007)]. Roughly speaking, this rule states that if the
wave function of a particle is split into non-overlapping wave packets, the particle stays approximately inside the support
of one of the wave packets, without jumping to the others.
In this paper a formal definition of this rule is given in terms of imprecise probability. An imprecise probability space is a measurable space
endowed with a set of probability measures ℘. The quantum formalism and the quantum typicality rule allow us to define a set of probabilities
on (X
T
,ℱ), where X is the configuration space of a quantum system, T is a time interval and ℱ is the σ-algebra generated by the cylinder sets. Thus, it is proposed that a quantum system can be represented as the imprecise stochastic process
, which is a canonical stochastic process in which the single probability measure is replaced by a set of measures. It is
argued that this mathematical model, when used to represent macroscopic systems, has sufficient predictive power to explain
both the results of the statistical experiments and the quasi-classical structure of the macroscopic evolution. 相似文献