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21.
L. R. Baker 《Optics & Laser Technology》1986,18(1)
A two channel microscope image comparator is described which is capable of quantifying all current national standard defects. It has been designed to solve the difficulties that arise when optically worked surfaces, which have been visually assessed, are transferred between companies working to different standards and methods of flaw measurement. The instrument, using both visual and objective methods, can give the same severity rating for a surface flaw, thus allowing for transferable standards. 相似文献
22.
In order to evaluate its relevance, we reconsider critically the recent proposal by Leggett and Garg to test macrorealism
against quantum mechanics by resorting to experiments involving noninvasive measurement processes on a SQUID. Our conclusion
is that, in spite of the fact that the proposed experiment would neither constitute a test of macrorealism nor a test of macrocontextuality,
a simplified form of it represents a (presumably) feasible experiment permitting a direct test of macroscopic quantum coherence.
We also analyze the proposal from the point of view of the recent attempts to build up model theories allowing to take, within
a purely quantum framework, a macrorealistic position about natural phenomena, i.e., the socalled dynamical reduction models
and we stress that the proposed experiment has no relevance for the dynamical reduction program, as developed so far. However
consideration of the SQUID system allows one to test other possible dynamical mechanisms leading to the objectification of
macroproperties which could, in principle, be operative. We also briefly sketch experimental procedures to be followed to
get all relevant information concerning macrocoherence. 相似文献
23.
The constitutive equations of finite strain poroelasticity in the light of a micro-macro approach 总被引:1,自引:0,他引:1
Patrick de Buhan Xavier Chateau Luc Dormieux 《European Journal of Mechanics - A/Solids》1998,17(6):909-921
After recalling the constitutive equations of finite strain poroelasticity formulated at the macroscopic level, we adopt a microscopic point of view which consists of describing the fluid-saturated porous medium at a space scale on which the fluid and solid phases are geometrically distinct. The constitutive equations of poroelasticity are recovered from the analysis conducted on a representative elementary volume of porous material open to fluid mass exchange. The procedure relies upon the solution of a boundary value problem defined on the solid domain of the representative volume undergoing large elastic strains. The macroscopic potential, computed as the integral of the free energy density over the solid domain, is shown to depend on the macroscopic deformation gradient and the porous space volume as relevant variables. The corresponding stress-type variables obtained through the differentiation of this potential turn out to be the macroscopic Boussinesq stress tensor and the pore pressure. Furthermore, such a procedure makes it possible to establish the necessary and sufficient conditions to ensure the validity of an ‘effective stress’ formulation of the constitutive equations of finite strain poroelasticity. Such conditions are notably satisfied in the important case of an incompressible solid matrix. 相似文献
24.
Precise Macroscopic Supramolecular Assembly by Combining Spontaneous Locomotion Driven by the Marangoni Effect and Molecular Recognition 下载免费PDF全文
Meng Xiao Yiming Xian Prof. Dr. Feng Shi 《Angewandte Chemie (International ed. in English)》2015,54(31):8952-8956
Macroscopic supramolecular assembly bridges fundamental research on molecular recognition and the potential applications as bulk supramolecular materials. However, challenges remain to realize stable precise assembly, which is significant for further functions. To handle this issue, the Marangoni effect is applied to achieve spontaneous locomotion of macroscopic building blocks to reach interactive distance, thus contributing to formation of ordered structures. By increasing the density of the building blocks, the driving force for assembly transforms from a hydrophobic–hydrophobic interaction to hydrophilic–hydrophilic interaction, which is favorable for introducing hydrophilic coatings with supramolecular interactive groups on matched surfaces, consequently realizing the fabrication of stable precise macroscopic supramolecular assemblies. 相似文献
25.
The main aim of this work is to develop a consistent formulation of the rheological behavior for different anisotropic polymer
systems. The unified theory of anisotropic viscoelasticity is developed based on the symmetry principles. The Maxwell rheological
equation is extended to nonsymmetric anisotropic liquids. Transitions from the most general anisotropy to particular cases
of anisotropy are established. It appears that the coupled relaxation of symmetric and antisymmetric stresses is a natural
phenomenon in nonsymmetric viscoelasticity. Within the concept of an internal state variable, a stress–order relation is derived
for a fully nonlinear case. The order tensor dynamics is also considered. A simple method of deriving the equation of the
internal rotational motion is developed for the general macroscopic anisotropy.
This paper was presented at the 3rd Annual Rheology Conference, AERC 2006, April 27–29, 2006, Crete, Greece 相似文献
26.
I. Yu. Malakhov K. A. Sveshnikov P. K. Silaev 《Theoretical and Mathematical Physics》2005,143(1):529-540
We propose a subtraction-free method for calculating the quantum-field vacuum energy in the presence of nontrivial boundary conditions and logarithmically divergent terms caused by them. The method can also be used in the case where the energy levels of a system are known only numerically. Moreover, its use requires neither knowledge of the analytic form of equations for certain levels or a detailed analysis of their asymptotic behavior.Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 143, No. 1, pp. 49–63, April, 2005. 相似文献
27.
The spin parity effect resulting from time-inversion symmetry is derived by generalizing the pure quantum theory of the effect
resulting from finite-fold axial-rotation symmetry. The quantum system concerned may consist of either one spin or many spins
with arbitrary spin quantum numbers and the states involved may be any pair of eigenstates of spin operator projected on arbitrary
axis with their eigenvalues having opposite signs. The two kinds of spin parity effect, resulting from time-inversion symmetry
and from axial-rotation symmetry, are in general not equivalent but complementary to each other.
Project supported by the National Natural Science Foundation of China (Grant No. 19677101). 相似文献
28.
For studying the problem of measurement we accept the statistical interpretation of quantum mechanics, but we take into account, that in a sequence of measurements, offdiagonal terms arise which cannot obviously be interpreted as the probability of a sequence of macroscopic events. We demonstrate, however, their vanishing for ordinary measurement processes by observing that the measurement apparatus undergoes a symmetry breaking transition during the measurement.1. On leave from the Central Research Institute for Physics, Budapest, Hungary. 相似文献
29.
In this paper we review the theory of cells (particles) that evolve according to a dynamics determined by friction and that interact between themselves by means of suitable potentials. We derive by means of elementary arguments several macroscopic equations that describe the evolution of cell density. Some new results are also obtained—a formal derivation of a limit equation in the case of attractive potential as well as in the case of repulsive potential with a hard‐core part are presented. Finally we discuss the possible relevance of those results within the framework of individual cell‐based models. Several classes of potentials, including hard‐core, repulsive and potentials with attractive parts are discussed. The effect of noise terms in the equation is also considered. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
30.
The problem considered is the detection of flaws of an elastic pole with vibration sources and measurement of vibration data known. It is reduced to an optimal control problem of systems with distributed parameters. By making use of the principle of pulse variation, some new gradient formulas and new optimization algorithms are obtained. Some simulation examples are attached to verify the theoretical analysis. Compared with the traditional method of flaw detection, the method here proposed makes fuller use of the dynamic information of the vibrating wave, and the limit of vibration sources is much broader. This method can be further used in designing on — line flaw detection apparatus.This work is supported by the Petrol Department Science Foundation. 相似文献