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Kinematic polarization

The conversion of the orbital angular momentum of the reagents to rotational angular momentum of the products in reaction (6.13) appears not only for heavy atom transfer reactions in heavy + heavy-light A+BC reactive scattering, but is also expected to be the case for other mass combinations and also for lower reactional orbital momentum values. As was shown in [337], the kinematic polarization of the reaction products can be... [Pg.228]

When the length scale approaches molecular dimensions, the inner spinning" of molecules will contribute to the lubrication performance. It should be borne in mind that it is not considered in the conventional theory of lubrication. The continuum fluid theories with microstructure were studied in the early 1960s by Stokes [22]. Two concepts were introduced couple stress and microstructure. The notion of couple stress stems from the assumption that the mechanical interaction between two parts of one body is composed of a force distribution and a moment distribution. And the microstructure is a kinematic one. The velocity field is no longer sufficient to determine the kinematic parameters the spin tensor and vorticity will appear. One simplified model of polar fluids is the micropolar theory, which assumes that the fluid particles are rigid and randomly ordered in viscous media. Thus, the viscous action, the effect of couple stress, and... [Pg.67]

Figure 4. Kinematics of the solid-state EMS spectrometer [11]. (a) The polar angles made by kf and k, with respect to the incident (z) direction are Of = 14° and 6% = 76°. In (b) is shown a typical sample membrane relative to the electron trajectories. The surface sensitivity is largely determined by the escape depth of the 1.2 keV electrons ( 2 nm) and is indicated by the shaded area. [Pg.211]

Despite the fact that Bohr s stopping power theory is useful for heavy charged particles such as fission fragments, Rutherford s collision cross section on which it is based is not accurate unless both the incident particle velocity and that of the ejected electron are much greater than that of the atomic electrons. The quantum mechanical theory of Bethe, with energy and momentum transfers as kinematic variables, is based on the first Born approximation and certain other approximations [1,2]. This theory also requires high incident velocity. At relatively moderate velocities certain modifications, shell corrections, can be made to extend the validity of the approximation. Other corrections for relativistic effects and polarization screening (density effects) are easily made. Nevertheless, the Bethe-Born approximation... [Pg.76]

The kinematics of the situation for the case of optical limit type (e,2e) experiments are illustrated in Fig. 2b (Fig. 1 b of Hamnett et al.23), which shows the direction of the ejected electron j as a function of the two polar angles x and y. The angle between j and the vector K is denoted by i//. Provided the forward scattering kinematics are such that K is small and we may approximate /(K) by /0m(0), then, as is well known, regardless of the detailed form of the continuum wave function, provided that k I is orthogonal to Pq 35... [Pg.20]

Vibrationally excited diatomic molecules will only emit if they are polar, and most of the available results are for reactions which produce diatomic hydrides. Because of their unusually small reduced mass, these molecules have high frequency and very anharmonic vibrations, and their rotational levels are widely spaced. Consequently, their spectra can be resolved more easily than those of nonhydrides, where there are many more individual lines in the vibration-rotation spectrum. Furthermore, the molecular dynamics of these reactions are particularly interesting because of the special kinematic features that arise when an H atom is involved in a reactive collision and because these... [Pg.55]

In a kinematically-complete ionisation experiment for an incident beam of momentum ko, the differential cross section is normally measured for a range of a single variable determining the momenta k/ and k of the faster and slower final-state electrons. The kinematic variables are the kinetic energies /, Eg, the polar angles Of, 6s, measured from ko, and the relative azimuthal angle... [Pg.262]

Ionization losses, multiple scattering, and the deflection in the local magnetic field are considered. The decay of particles is simulated in exact kinematics, and the muon polarization is taken into account. [Pg.400]

Spectropolarimetry has proven to be an important tool in the development of unified theories of active galactic nuclei (AGN). Its strength is that it provides an alternative view of the inner regions of the active nucleus. This allows for the study the stracture and kinematics of both polarizing materials and the emission source. Examples of polarization spectra of two active galaxies NGC 5548 and Was 45 are given in Fig. 15. The observations of NGC 5548 were made in 1997 and Was 45 in 1999 with the 1.2m William Hershel Telescope. [Pg.468]

The dimensions of a are the same as those of the diffusion coefficient and of the kinematic viscosity, therefore the process of heat transport due to conduction can be treated as the diffusion of heat with the diffusion coefficient a, bearing in mind that the transport mechanisms of diffusion and heat conductivities are identical. The coefficient of heat conductivity of gases increases with temperature. For the majority of liquids the value of k decreases with increasing T. Polar liquids, such as water, are an exception. For these, the dependence k(T) shows a maximum value. As well as the coefficient of viscosity, the coefficient of heat conductivity also shows a weak pressure-dependence. [Pg.51]

For a given model of the structure normal to the interface, no matter how complex, it is possible to calculate the neutron reflectivity exactly using the same formulae, apart from the difference in the refractive index, as for light polarized at rightangles to the plane of reflection. For a multilayer structure the optical matrix method [4] can then be used, in which the interface is divided into as many layers as are required to describe it with adequate resolution. This method lends itself especially well to machine calculations and is therefore the most widely used method of analysing neutron reflectivity. However, it does not reveal the relatively simple relation between reflectivity and interfacial structure, which can be done more clearly using the kinematic approximation. In the kinematic approximation the reflectivity profile is given by [5,6]... [Pg.223]


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See also in sourсe #XX -- [ Pg.228 , Pg.229 ]




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