Big Chemical Encyclopedia

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

Articles Figures Tables About

Order inverse

Elements of the zeroth-order, inverse-propagator matrix are... [Pg.39]

Corrections to the zeroth-order, inverse propagator in equation 26 are gathered together in a term known as the self-energy matrix, E(E). The Dyson equation may be written as... [Pg.39]

Rate dependence on carbon monoxide pressure. zero order inverse first order inverse first order inverse first order... [Pg.132]

We shall discuss briefly the physical meaning of various terms which occur in the expansion of our Hamiltonian and the corresponding approximations. The sim-pliest approximation to is obtained when all the small-amplitude vibrational coordinates (k = 1, 3a, 3b, 4a, Ab) are put equal to zero. We shall call this Hamiltonian the zeroth-order inversion—rotation Hamiltonian, or the rigid bender Hamiltonian. It follows from Eqs. (3.23) and (3.33)—(3.38) that it can be written in the following form ... [Pg.74]

Consider briefly now the Schrodinger equation for the zeroth-order inversion HamiltonianJP i ... [Pg.74]

FIGURE 4.6 Schematic showing the approach used to produce highly ordered inverse opal structures with conducting polymers. [Pg.171]

Short 1/7° 1/7 x changes, not first-order Inversely proportional toV7... [Pg.16]

Some indication of how theory compares with observation is given in Table II which shows the relative rates at which methyl radicals attack some of the compounds of interest (2). Notice that all rates are ordered inverse to delocalization energies. Values of DE quoted in Table II and hereafter have been nondimensionalized by the Hiickel factor 2/2 this nondimensional DE is also known as the Dewar number. The pattern of Table II is observed for a variety of other aromatic reactions such as nitration and sulfonation (I). Among the molecules considered in this study (Table I), benzene and anthracene represent the extremes of reactivity. [Pg.247]

A chirality classification of crystal structures that distinguishes between homochiral (type A), heterochiral (type B), and achiral (type C) lattice types has been provided by Zorkii, Razumaeva, and Belsky [11] and expounded by Mason [12], In the type A structure, the molecules occupy a homochiral system, or a system of equivalent lattice positions. Secondary symmetry elements (e.g., inversion centers, mirror or glide planes, or higher-order inversion axes) are precluded in type A lattices. In the racemic type B lattice, the molecules occupy heterochiral systems of equivalent positions, and opposite enantiomers are related by secondary lattice symmetry operations. In type C structures, the molecules occupy achiral systems of equivalent positions, and each molecule is located on an inversion center, on a mirror plane, or on a special position of a higher-order inversion axis. If there are two or more independent sets of equivalent positions in a crystal lattice, the type D lattice becomes feasible. This structure consists of one set of type B and another of type C, but it is rare. Of the 5,000 crystal structures studied, 28.4% belong to type A, 55.6% are of type B, 15.7% belong to type C, and only 0.3% are considered as type D. [Pg.367]

Fig. 6 Probe molecule flux as a function of film thickness for an interfacially polymerized film derived from molecular square 14Zn and succinyl chloride. The line is drawn to show a first order inverse fit to the data. (Inset shows linearity of the reciprocal plot.) Adapted from [28]... Fig. 6 Probe molecule flux as a function of film thickness for an interfacially polymerized film derived from molecular square 14Zn and succinyl chloride. The line is drawn to show a first order inverse fit to the data. (Inset shows linearity of the reciprocal plot.) Adapted from [28]...
In a different approach again, the open porosity of an ordered inverse siUca opal material has been filled by multiple impregnation steps with sulfonated polysulfone (sPSU). In a highly polymer-charged composite, the polymer and silica phases are co-continuous, and the conductivity of a material with mass ratio of polymer to silica of 70 30 was ca. 0.1 Scm at 80 °C and 90% RH,... [Pg.241]

One of the classic studies in which the viscosity dependence of kt was investigated originates from the early sixties. North and Reed [62] studied the termination rate coefficients of a series of alkyl methacrylates, in particular MMA [63], These authors used various solvents, all of them exhibiting comparable solvent power for the specific polymers being studied. Only for the smallest methacrylate studied, MMA, an approximate first-order inverse dependence was found between kt and the inherent solution viscosity, /. Several years earlier, Benson and North [40] had reported similar results for MMA and this dependence was later abundantly confirmed by others [66-71, 73, 74, 86]. Also for the monomer styrene this inverse first-order dependence was found [75, 76]. The larger methacrylates also showed an inverse dependence of kt upon solution viscosity, though less strongly than for MMA. [Pg.17]

Addition of chlorine to cyclo-octatetraene is unusually fast and gives exclusively the cis-1,2-dichloride, presumably via (295) the latter can be efficiently obtained as a hexachloroantimonate by reaction of cyclo-octatetraene with antimony pentachloride. The tetrafluoroborate of (295) can be converted into (296) in a first-order inversion which is strongly catalysed by cis-7,8-dichlorocyclo-octa-l,3,5-triene. ... [Pg.303]

A number of semitheoretical models have been proposed to describe the bond-energy curve in ionic-bonded and van der Waals-bonded systems in which the attractive force can be described accurately by an inverse power law. The repulsive potential is described by an exponential or a high order inverse power law. Such potentials are useful for relating physical properties such as the bulk modulus and elastic modulus to the lattice energy. Unfortimately, there are no simple lattice models that can be applied to metallic or covalently bonded systems. [Pg.57]


See other pages where Order inverse is mentioned: [Pg.215]    [Pg.218]    [Pg.719]    [Pg.211]    [Pg.187]    [Pg.334]    [Pg.407]    [Pg.160]    [Pg.102]    [Pg.9]    [Pg.9]    [Pg.9]    [Pg.16]    [Pg.16]    [Pg.247]    [Pg.187]    [Pg.70]    [Pg.175]    [Pg.52]    [Pg.236]    [Pg.429]    [Pg.109]    [Pg.239]    [Pg.31]    [Pg.311]    [Pg.69]    [Pg.135]   
See also in sourсe #XX -- [ Pg.79 ]




SEARCH



Inverse first order

Order tensor inversion symmetry

© 2024 chempedia.info