共查询到20条相似文献,搜索用时 0 毫秒
1.
V. P. Koscheev 《Technical Physics Letters》2002,28(4):318-319
A theory describing the bulk trapping of heavy relativistic particles into a channeled transport mode is constructed. It is demonstrated that a discrete character of the atomic plane potential in a bent crystal explains the elastic energy losses for the transverse motion of channeled particles, which exceed the inelastic losses for the same motion by a factor of 107. 相似文献
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Hardy L 《Philosophical transactions. Series A, Mathematical, physical, and engineering sciences》2012,370(1971):3385-3417
In this paper, we provide what might be regarded as a manifestly covariant presentation of discrete quantum theory. A typical quantum experiment has a bunch of apparatuses placed so that quantum systems can pass between them. We regard each use of an apparatus, along with some given outcome on the apparatus (a certain detector click or a certain meter reading for example), as an operation. An operation (e.g. B(b(2)a(3))(a(1))) can have zero or more quantum systems inputted into it and zero or more quantum systems outputted from it. The operation B(b(2)a(3))(a(1)) has one system of type a inputted, and one system of type b and one system of type a outputted. We can wire together operations to form circuits, for example, A(a(1))B(b(2)a(3))(a(1))C(b(2)a(3)). Each repeated integer label here denotes a wire connecting an output to an input of the same type. As each operation in a circuit has an outcome associated with it, a circuit represents a set of outcomes that can happen in a run of the experiment. In the operator tensor formulation of quantum theory, each operation corresponds to an operator tensor. For example, the operation B(b(2)a(3))(a(1)) corresponds to the operator tensor B(b(2)a(3))(a(1)). Further, the probability for a general circuit is given by replacing operations with corresponding operator tensors as in Prob(A(a(1))B(b(2)a(3))(a(1))C(b(2)a(3))) = ?(a(1))B(b(2)a(3))(a(1))C(b(2)a(3)). Repeated integer labels indicate that we multiply in the associated subspace and then take the partial trace over that subspace. Operator tensors must be physical (namely, they must have positive input transpose and satisfy a certain normalization condition). 相似文献
3.
A linearization is performed of a previously presented, so-called grade-consistent micropolar theory, where the free energy is assumed to contain also second order derivatives of the displacement, an order which is argued to match the conventional first order derivatives of the micropolar angle. Dimensionless constitutive constants are introduced, which facilitates the discussion of orders of magnitude. The theory is applied to harmonic plane waves. By means of the dispersion relations the possible magnitudes of the different, conventional and new micropolar effects are preliminarily discussed. 相似文献
4.
A theory is presented for linear, AC magnetic circuits. The theory develops real and imaginary reluctance terms, which are used in the same manner as real and imaginary impedance terms in linear, AC electrical circuit theory. The reluctance terms can be manipulated through coil-coupled resistances and capacitances. The theory is applied to a parallel magnetic-circuit configuration to show the limits of applicability for the particular materials from which the circuit is constructed 相似文献
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A new approach to near-infrared (NIR) spectropolarimetry is described, in which the properties of a noncollinear acousto-optical tunable filter (AOTF) made of an anisotropic crystal of TeO2 is employed to produce a novel instrument that precludes or reduces significantly the use of mechanical parts and simplifies the acquisition of optical rotation spectra of absorbing species in the NIR region. In essence, the instrument is based on the measurement of the relative beam intensities produced when a 45 degrees plane polarized beam of radiation passes through a sample cell and is directed to the entrance window of the AOTF. Because of the crystal anisotropy, two planar and orthogonally polarized beams will leave the AOTF, angularly split from the nondiffracted beam, after the acousto-optical interaction has occurred. If an optically nonactive sample is present in the cell, equal intensities for both diffracted beams should be observed. On the other hand, the presence of an optically active sample will cause the polarization plane to rotate and a consequent difference in the intensities of the AOTF diffracted beams will be registered as a function of the optical activity of the sample. The instrument has been evaluated with aqueous solutions of sucrose, glucose, and fructose and for three forms of camphor (d, l, dl). 相似文献
6.
We review the operating principles of noncollinear acousto-optic tunable filters (AOTF's), emphasizing the use of two orthogonally polarized beams for narrow-band imaging. Spectral characterization and spectral broadening measurements of commercially available AOTF's agree with theoretical predictions and reveal difficulties associated with imaging noncollimated light. An AOTF imaging spectropolarimeter for ground-based astronomy that uses CCD's has been constructed at NASA Goddard Space Flight Center. It uses a TeO(2) noncollinear AOTF and a simple optical relay assembly to produce side-by-side orthogonally polarized spectral images. We summarize the instrument design and initial performance tests. We include sample spectral images acquired at the Goddard Geophysical and Astronomical Observatory. 相似文献
7.
van Trigt C 《Journal of the Optical Society of America. A, Optics, image science, and vision》2007,24(9):2684-2691
Linear models in color constancy theory face, at least, five major problems different in nature, to be solved as a prerequisite for a satisfactory theory of the phenomenon. Solutions are proposed. 相似文献
8.
We present an approach to spectropolarimetry that requires neither moving parts nor time dependent modulation, and that offers the prospect of achieving high sensitivity. The technique applies equally well, in principle, in the optical, UV, or IR. The concept, which is one of those generically known as channeled polarimetry, is to encode the polarization information at each wavelength along the spatial dimension of a two-dimensional data array using static, robust optical components. A single 2D data frame contains the full polarization information and can be configured to measure either two or all of the Stokes polarization parameters. By acquiring full polarimetric information in a single observation, we simplify polarimetry of transient sources and in situations where the instrument and target are in relative motion. The robustness and simplicity of the approach, coupled with its potential for high sensitivity, and applicability over a wide wavelength range, is likely to prove useful for applications in challenging environments such as space. 相似文献
9.
We propose a simple procedure for designing an integrated single-chip grating-based thin-film filter. A simulation from a rigorous coupled-wave analysis shows that structural adjustment based on the effective medium theory can achieve the desired integration without notable performance degradation. Our spectropolarimetric filter design maintains spectral filter characteristics, while its extinction ratio is significantly enhanced over the passband. The integrated spectropolarimetric filter can be a basis for building multispectral multipolarimetric filters for spectropolarimetry in remote-sensing applications. 相似文献
10.
V. L. Kolpashchikov A. I. Shnip 《Journal of Engineering Physics and Thermophysics》1984,46(6):732-739
Restrictions on the relaxation functions of heat conduction, which are necessary and sufficient for the fulfillment of the thermodynamic postulates in a linear theory of heat conduction with memory, are obtained.Translated from Inzhenero-Fizicheskii Zhurnal, Vol. 46, No. 6, pp. 1008–1017, June, 1984. 相似文献
11.
S. H. Guo 《Acta Mechanica》2012,223(3):541-547
The dissipation field of a continuum is studied here by a new operator theory of irreversible thermodynamics; the evolution equations of the dissipation field can be obtained in the condition of knowing the phenomenological nonlinear constitutive relation of materials. In this theory, the basic state equation, which is the state of minimum dissipation, is utilized for solving the distribution of the dissipation field of quasi-statics, and the higher order state equations are corresponding to the dissipation fields of dynamics. The paper also gives a method to get the dissipation force operator by using Helmholtz’s free energy function. In the final part of this paper, several important phenomena of the localized deformation, such as the plastic instability of necking and shear band, are predicted in the form of an analytical formula. 相似文献
12.
A linear theory of memory-dependent micropolar viscoelastic materials with stretch has bean developed. Linear constitutive functionals have been considered to depend on the continuous past history of the strain measures, micro-rotation gradient, stretch and stretch gradients. The constitutive equations of isotronic linear micronolar viscoelastic materials with stretch have been obtained as a particular case by neglecting the past history of the motion. 相似文献
13.
K. K. Puri 《Journal of Engineering Mathematics》1970,4(3):283-290
Summary We consider the motion of an inviscid, incompressible fluid with surface tensionT, in an infinite channel of finite depth, when a pressure disturbance is imposed on the uniform stream. The explicit solution of the resulting initial value problem is presented. Also, possible steady state flows are discussed. In the cases when they exist, corresponding radiation conditions are found. 相似文献
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The equations of the nonlocal elasticity given in [1]and[2] are linearized. The dispersion relations are obtained for one dimensional plane waves. The nonlocal material moduli are determined to fit exactly the acoustical branch of elastic waves within one Brillouin zone in periodic one dimensional lattices. 相似文献
17.
S. I. Éminov 《Technical Physics Letters》2004,30(11):933-936
Analytical inversion of the hypersingular operator is obtained and used to develop an effective numerical-analytical method of solving hypersingular integral equations. Applications of the inverse operator to the theory of antennae are considered. 相似文献
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V. P. Koshcheev 《Technical Physics Letters》2001,27(9):784-785
A stochastic equation for the evolution of the transverse energy of high-energy charged particles moving in planar and axial channels in a crystal is derived using the condition of nonconservation of the adiabatic invariant. 相似文献
20.
Dyankov G 《Applied optics》2008,47(4):536-540
A simple and effective technique for the simultaneous measurement of the refractive index and the thickness of thin films is proposed. The method is based on the spectral dependence of the visibility of interference fringes that result from thin-film interference when the film is illuminated with a white light. The film is on the special substrate, and an optical contact is provided between them. The measurement consists of finding the local change of the fringes' visibility in the observed channeled spectrum expressed as the seaming change of the fringes' periodicity. The method can be applied for real time optical inspection during the manufacturing of thin polymer films. 相似文献