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Screening propagator

Expressing finally the self-energy operator Z in eq.(3.5) in the TDSHF and employing the local representation in eq.(3.6) for the screening propagator, we arrive at the following expression for the matrix elements of I (only the non-HF part)... [Pg.134]

Sometimes conveying (qv) velocities, typically 20—25 m/s, exceed the flame-propagation rate as determined by tests. Moreover, velocities vary throughout the system. If the flame-propagation rate exceeds the conveying velocities, consideration must be given to the isolation of parts of the system by choking, ie, the use of rotary values, screen conveyors, bins, etc. [Pg.442]

The actual computation is broken down into two steps (1) A Collision Step, during which the value of a site is sent to a computation look-up table, with its input written to the display screen memory as in CAM-6. RAPl s screen memory consists of 16 256 x 512 planes, (2) A Propagation Step, during which the system is decomposed into a set of one-bit two-dimensional planes (one plane for each bit of each site), and the bits of each site are displaced to one of the site s neighbors by a translation of the entire plane. [Pg.716]

In astronomy, we are interested in the optical effects of the turbulence. A wave with complex amplitude U(x) = exp[ irefractive index, resulting in a random phase structure by the time it reaches the telescope pupil. If the turbulence is weak enough, the effect of the aberrations can be approximated by summing their phase along a path (the weak phase screen approximation), then the covariance of the complex amplitude at the telescope can be shown to be... [Pg.6]

The most studied catalyst family of this type are lithium alkyls. With relatively non-bulky substituents, for example nBuLi, the polymerization of MMA is complicated by side reactions.4 0 These may be suppressed if bulkier initiators such as 1,1-diphenylhexyllithium are used,431 especially at low temperature (typically —78 °C), allowing the synthesis of block copolymers.432,433 The addition of bulky lithium alkoxides to alkyllithium initiators also retards the rate of intramolecular cyclization, thus allowing the polymerization temperature to be raised.427 LiCl has been used to similar effect, allowing monodisperse PMMA (Mw/Mn = 1.2) to be prepared at —20 °C.434 Sterically hindered lithium aluminum alkyls have been used at ambient (or higher) temperature to polymerize MMA in a controlled way.435 This process has been termed screened anionic polymerization since the bulky alkyl substituents screen the propagating terminus from side reactions. [Pg.24]

The micrograph or the image obtained on an EM screen, photographic film, or (more commonly today) a CCD is the result of two processes the interaction of the incident electron wave function with the crystal potential and the interaction of this resulting wave function with the EM parameters which incorporate lens aberrations. In the wave theory of electrons, during the propagation of electrons through the sample, the incident wave function is modulated by its interaction with the sample, and the structural information is transferred to the wave function, which is then further modified by the transfer function of the EM. [Pg.204]

P(E) is called the irreducible polarization propagator, and W( ) the dielectrically screened interaction. [Pg.40]


See other pages where Screening propagator is mentioned: [Pg.2208]    [Pg.3029]    [Pg.45]    [Pg.233]    [Pg.360]    [Pg.197]    [Pg.98]    [Pg.131]    [Pg.14]    [Pg.287]    [Pg.601]    [Pg.2]    [Pg.6]    [Pg.224]    [Pg.39]    [Pg.29]    [Pg.451]    [Pg.205]    [Pg.206]    [Pg.269]    [Pg.173]    [Pg.58]    [Pg.66]    [Pg.106]    [Pg.166]    [Pg.39]    [Pg.413]    [Pg.32]    [Pg.318]    [Pg.91]    [Pg.83]    [Pg.119]    [Pg.268]    [Pg.47]    [Pg.71]    [Pg.77]    [Pg.588]    [Pg.56]    [Pg.52]   
See also in sourсe #XX -- [ Pg.14 , Pg.588 ]




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