Identity distance

The main macrokinetic problem to be solved for the description of this reaction is finding the evolution of the profile of concentrations Mi, M2 of monomeric units Mi, M2 inside a globule with radius R. By virtue of the spherical symmetry of the problem, concentration M is the same at all points of a globule located at identical distance r from its center. The same condition is apparently met by the concentrations of the second type units M2 = Mj0 - Mi and low-molecular reagent Z. Presuming monomeric units to... 

There are two stable arrangements of nearly completely extended polypeptide chains forming hydrogen bonds with neighboring chains.114 They are the parallel-chain pleated sheet (Fig. 12-19) and the anti-parallel-chain pleated sheet (Fig. 12-20). The identity distance in the direction of the chains is found to be different for the two structures when the requirement that the N—H---0 bonds be linear is imposed ... 

Another indication that precipitation and not adsorption is operative depends on the observation that samples of the same molecular weight migrate identical distances from the dip line, independent of their starting positions on the TLC plate (15). This of course would not be the case if adsorption governed chromatographic mobility. To explain these phenomena, Inagaki has proposed that the solvent concentration profile results... 

To specify the position of a point within or on the surface of a unit cell, a system of coordinates similar to ordinary Cartesian coordinates is used. The corner of a cell is selected as the origin, and distances to the point are measured parallel to each axis these distances are expressed in terms of the identity distances along the respective axes. This is best shown in a two dimensional lattice (Fig. 20-3). Here there are four two-dimensional... 

Using Figure 20-10, derive equation (4), the relationship between J, the identity distance along the axis of rotation for a rotating-crystal photo, and a, the angle of incidence on the film at the first layer line. 

The plot above has been produced with six identical distances from the centroid of the ligand (the metal center) to the amines. A non-spherical metal ion (e.g., a Jahn-Teller labile copper(II) ion) will induce different stresses to a symmetrical ligand. Alternatively, the ligand might be asymmetrical, i. e., the ligand itself might induce an asymmetry in the coordination sphere. Effects like these will be studied in Section 17.17. 

If in a complex the direct neighbor nuclei have the same atomic number and are located at identical distances from the central atom, then the coordination number of this atom can be specified exactly. Complexes with identical ligands are called homoleptic. However, when the nearest neighbor nuclei are not identical, the distances from the central atom will be different, although those nuclei may still be located on the Cartesian coordinates. In these heteroleptic complexes, specify-... 

For this crystal it is seen that a cycle for the coordinate z is the identity distance d, so that (p, being constant in the absence of forces acting on the crystal) the quantum rule becomes... 

Bamford, Hanby, and Happey report interplanar distances leading to fiber-axis pseudo identity distances of 5-75 A for each of the three copolymers poly-DL-jS-phenylalanine, poly-(DL-/3-phenylalanine 7-methyl-L-glutamate), and poly-(DL-j8-phenylalanine L-leucine). Larger steric repulsion of side chains would be expected for these copolymers than for poly-y-methyl-L-glutamate. 

The meridional reflections observed by Corey and Wyckoff and by Bear are given in table 2. They can nearly all be accounted for as orders of a large identity distance, 94.6 A. In addition to the meridional reflections given in table 2, Bear reported a number of small-angle near-meridional reflections, corresponding to other orders of the identity distance 94.6 A. 

The identity distance 94.6 A receives a rational explanation as resulting from the presence of two structures, the slightly distorted pleated sheet with identity distance along the a axis of 6.30 A, and the a helix with 5.57 A per turn. The simplest ratio of integers approximating the ratio of these numbers is 17 15, corresponding to the mutual identity distance... 

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