Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Particle localization

Let < j(k) be the Klein-Gordon amplitude corresponding to a spin zero particle localized at the origin at time t = 0. Since in momentum space the space displacement operator is multiplication by exp (— tk a), the state localized at y at time t = 0 is given by exp (—ik-y) (k). This displaced state by condition (b) above must be orthogonal to (k), i.e. [Pg.501]

The configuration space amplitude at time t = 0 corresponding to a particle localized at t — 0 at the point y is obtained from (k) by substituting the latter expression into Eq. (9-92) ... [Pg.501]

More generally, the configuration space amplitude corresponding to a particle localized at time y0 at the spatial point y is given by... [Pg.502]

Two limiting cases chaos and order are determined here, but in addition one can also consider chaos with some correlation to particles localization (type 3, Table 9.3) type 4 assumes presence of some order, for example long-range order in silicate mesophases, or platinum particles in a xerogel, etc. One can also consider division of these types, which allow or disallow overlapping of particles. [Pg.296]

The many-particle local point of view (Mott-Hubbard theory)... [Pg.129]

Fig. 4 Transmission electron microscopy of a longitudinal section of the posterior end of a Cryptosporidium parvum sporozoite showing immunogold localization of pyruvate NADP+ oxidoreductase (CpPNO). The mitochondrion-like organelle ( ) is posterior to the nucleus, and lies between the nucleus and the CB. It is labeled by mitochondrion-specific 15-nm gold anti- particles. Small -nm gold goat anti-CpPFO particles (arrows) show the localization of CpPNO. There are no 6-nm particles localized within the mitochondrion-like organelle (reprinted from Fig. 12 of Ctrnacta et al. 2006 with permission of the publishers)... Fig. 4 Transmission electron microscopy of a longitudinal section of the posterior end of a Cryptosporidium parvum sporozoite showing immunogold localization of pyruvate NADP+ oxidoreductase (CpPNO). The mitochondrion-like organelle ( ) is posterior to the nucleus, and lies between the nucleus and the CB. It is labeled by mitochondrion-specific 15-nm gold anti- particles. Small -nm gold goat anti-CpPFO particles (arrows) show the localization of CpPNO. There are no 6-nm particles localized within the mitochondrion-like organelle (reprinted from Fig. 12 of Ctrnacta et al. 2006 with permission of the publishers)...
This must be equal to the rate at which these atoms are incorporated into the particle locally at the interface. The rate at which B atoms in the matrix transfer to the particle across the a/(3 interface will be proportional to the local matrix concentration. The reverse rate of transfer from the particle to the matrix will be the same as the rate of transfer from the matrix to the particle that would occur under equilibrium conditions when detailed balance prevails. The net rate of transfer will then be... [Pg.323]

We should note that a two-humped absorption are pertinent to aqueous media. In terms of a microscopic molecular model, such a behavior could, partially, be explained by a finite depth of a potential well. Indeed, dipoles with rather small energies constitute a subensemble of particles localized in the well, so their maximum deflection (3 is determined by the angular width of the well, while dipoles with sufficiently large energies overcome the potential barrier. These dipoles perform a complete rotation such particles occupy the whole sphere, so that (3 = 7i. This reasoning leads us to a conclusion that generally two types of motion could characterize a given potential well, so that... [Pg.104]

Note that we consider here a mean localization, for which it is important to account for existence of two subensembles, characterized by the parameters (3 and (3. In the above-mentioned case of a finite-depth potential well, the deeper the well, the greater the proportion of the particles localized in it and the narrower in average the localization. On the basis of these considerations, we shall show in Section IV, where such a potential will be considered, that dependence of the position xD on the well depth agrees with the rule (61). Note, the loss-peak intensity yj) also obeys the dependence given by Eq. (60c). However, its increase with an augmentation of the well depth is rather small, while the dependence of the relaxation time on the mean localization is much more essential. [Pg.106]

Solution and Dispersion Behavior. For the dyeing process in aqueous liquor, the dye must have adequate solubility or dispersibility. In general, good solubility is necessary for good application properties. If the solubility is poor (i.e., if any of the dye is present in the dye liquor in the form of undissolved particles), local coloration (specks), spots, uneven effects, and poor fastness can be produced, leading to serious defects and costly complaints. [Pg.347]

In equation (2) E is the (potential) energy of the proton (deuteron) subsystem and erf are considered as classical dihotomic variables erf = 1. These values correspond to particles localized in one of two possible equilibrium positions on each H-bond. [Pg.580]

White phosphorus particles can bum on the surface of the skin or penetrate deep into the tissues when carried on shrapnel particles. Local destruction of tissues continues as long as white phosphorus is exposed to oxygen. White phosphorus smoke with a garlic odor is characteristic of white phosphorus burns (Eldad and Simon 1991). High mortality rates seen... [Pg.21]

We observe that this corresponds to the non-interacting system but in the presence of a one-particle local potential so that from one can obtain certain one-particle properties the same as for the interacting system, for example, the density of the system. Then write... [Pg.196]

Another set of questions deals with the properties of single-particle localized excitations in disordered systems and its display in EELS. This problem is directly connected with the question of different mechanisms of energy transmission in disordered systems [5]. It is particularly interesting to investigate the EELS lineshape in a long-living single resonance near the critical point of a phase transition in a pure system or near the point of phase separation in a mixture [6]. [Pg.114]

An attempt was made to measure the particle local velocity at 1.5 pipe diameters downstream of the elbow by using a particle velocity probe (56). However, the technique failed, presumably because the strong secondary fiow prevented the velocity probe from being aligned with the velocity vector. For this reason, velocities obtained at 22 pipe diameters downstream of the elbow had to be used to estimate the concentrations at this level (1.5 pipe diameters). Figure 20 shows the estimated solids concentration normalized by the discharge concentration CJC ) for fine and medium sand particles 1.5 pipe diameters downstream of the elbow. Most of the relative concentrations are lower than unity, and consequently the mean concentration based on these measurements would be lower than the true value. Similar findings were obtained by Sansone (57) in gas-solid systems downstream of a 90 elbow. This phenomenon occurs because the velocity vector and the probe axis are not colinear, so that the concentration results are only of qualitative value. [Pg.193]

In the case of higher charge, Z 30 on Fig. 8a, both models result that the like-charged particles being confined to a film that has a thickness around H/D = 7.5 tend to be organized into four particle layers. For the middle-film layers formed with and without excluded volume forces, only some quantitative differences in the particle local density distribution are observed. The main difference introduced by excluded volume forces is found in the surface layers. Taking into account the discrete nature of the solvent results that the surface layers themselves show a structuring with respect to the film surfaces. [Pg.272]

Numerical calculations using Kapuy s partitioning scheme have shown that for covalent systems the role of one-particle localization corrections in many-body perturbation theory is extremely important. For good quality results several orders of one-particle perturbations have to be taken into account, although the additional computational power requirement is much less in these cases than for the two-electron perturbative corrections. Another alternative for increasing the precision of the calculations is to estimate of the asymptotic behavior of the double power series expansion (24) from the first few terms by applying Canterbury approximants [31], which is a two-variable generalization of the well-known Pade approximation method. It has also been found [6, 7] that in more metallic-like systems the relative importance of the localization corrections decreases, at least in PPP approximation. [Pg.59]

A proper solvated electron is a particle localized in the potential well of a polar medium, the well being created by the interaction of electron charge with the permanent and induced dipole moments of the nearest as well as remote neighbours. This notion of the nature of a solvated electron, based on the idea that the Landau-Pekar theory initially advanced for solid bodies can be applied also to liquid systems, was advanced in 1948 since then considerable efforts have been made to develop it and verify it experimentally. In most liquid systems, localization of an electron is followed by the formation of a cavity where most of the density of the solvated electrons is concentrated. The cavity is surrounded by the orientated dipoles of the solvent. Usually, the radius of this cavity equals about 3-3.5 A which conforms to a solvated-electron molar volume of 70-100 cm . This is the reason why solutions with large concentrations of solvated electrons have a lower density. [Pg.152]

Intravenously injected colloids distribute within the body according to the phagocytic function of the reticuloendothelial system (RES). Size has considerable influence on the biodistribution of colloidal particles. With a particle size of 0.3-0.6 pm, 80-90% of the radioactivity is seen in the liver, with 5-10% seen in the spleen and 5-9% in the bone marrow (Adams et al. 1980 Colombetti 1974 Lin and Winchell 1972 Nelp 1975 Wha-teley and Steele 1985). Larger colloidal particles show increased splenic uptake, whereas smaller particles localize in the bone marrow (Schuind et al. 1984 Subramanian and McAfee 1970). [Pg.204]

Individual heat-transfer coefficient, W/m -°C or Btu/ft -h-°F h, based on arithmetic mean temperature drop average over inside of tube h , for outside of tube or particle local value h i, at trailing edge of plate h, for fully developed flow in long pipes hg, local value outside tube... [Pg.369]

The differential equation (206) determines the trajectory of any given dipole. Since 9 = y/h — V(9) and V(6) > 0, it follows from (206) that the solution of its equation exists only ifh < v(0). Therefore the energy h of a particle, localized in the well, cannot exceed V(/ ). The laws of motion 0(f), (j>(t) are such, that the orientation 6 of a dipole relative the symmetry axis oscillates between two values 0min and 0max, at which 0 = 0, namely h = V(9). [Pg.477]

The regions C and V, to which the spectral functions L(z) and L(z) correspond, are occupied by the particles localized in the well. Any -particle penetrates into the flat part of the well. We may conditionally call it libratorThe P-particle, conditionally called precessor, move only in the parabolic part of the well and has energy h close to that, for which the effective potential V(9) undergoes its minimum, in which... [Pg.477]

For example, one obtains for the entropy of N particles localized on M sites. [Pg.286]

MOhm Isolated particles, localization on the polymer spheruhte surface... [Pg.206]

Thus, when the CdS particles localize on the outer surface of the vesicle membranes, the quantum yield of the CigV photoreduction appears to be much larger than at the localization of the CdS nanoparticles in the inner cavities of the vesicles, due to a greater accessibility of the CdS nanoparticles for the redox-active reagents. It was found that the nature of the CdS precursor also influences the quantum yield of the viologens reduction. For example, the presence of the EDTA anions, which serve as additional electron donors, enlarge the quantum yield. Besides, the quantum yield increases with increase in the CigV concentration inside the membrane. [Pg.609]

Figure 1. (a) Transverse local photonic DOS (%) for the two-level atom in the centers of the four zigzag CNs (x is the dimensionless frequency), (b) Two-particle local photonic DOS functions S (solid lines) and f (dashed lines) taken at the peak frequencies of if 00 [see (a)], as functions of the distances between the two atoms on the axes of the (10,0) (lines 1 x=0.29), (11,0) (lines 2 v=0.25) and (12,0) (lines 3 x=0.24) CNs (see Ref. [5] for more details), (c) Optical absorbtion lineshapes for the atom at different distances outside the metallic (9,0) CN, demonstrating the formation of the atomic quasi-ID polariton state as the atom approaches the CN surface (see Ref. [10] for more details), (d) Upper-level population decay probability of initially excited atom A (lines 1) and initially unexcited atom B (lines 2), and the two-qubit atomic entanglement (lines 3), as functions of dimensionless time r for the two atoms in the center of the metallic (9,0) CN separated from each other by the distance of 6.3/U = 22.2 A (see Ref. [6] for more details). [Pg.34]

In these systems, it is possible to obtain low percolation thresholds if a double percolation is present, that is, particle and phase percolation. This effect may be observed when the conductive particles, localized preferentially in one polymer phase, have a concentration equal or larger than the electric percolation threshold, and when the host polymer phase is the matrix or continuous phase of the polymer blend [155]. There are several models that describe the electroconductivity of these systems the effective medium theory, the onset for percolation theory, and thermodynamic models. Sumita s model considers the formation of chainlike conductive structures [151, 156]. [Pg.597]


See other pages where Particle localization is mentioned: [Pg.478]    [Pg.385]    [Pg.140]    [Pg.364]    [Pg.134]    [Pg.208]    [Pg.209]    [Pg.164]    [Pg.165]    [Pg.529]    [Pg.308]    [Pg.163]    [Pg.44]    [Pg.43]    [Pg.46]    [Pg.188]    [Pg.26]    [Pg.8]    [Pg.210]    [Pg.139]    [Pg.478]    [Pg.35]    [Pg.483]   
See also in sourсe #XX -- [ Pg.365 ]




SEARCH



© 2024 chempedia.info