Layer structure, schematic

Studies of the condensed chromatin fibre structure and the condensation mechanism have resulted in basically two classes of models models based on a helical arrangement of nucleosomes along the fibre and those based on a linear array of globular nucleosome clusters (superbeads) along the fibre. The first class includes the solenoid, twisted ribbon and crossed linker models whereas the latter are the superbead models and related layered structures. Schematic representations of some models are shown in Fig. 10. 

Some unique behaviour can be installed in membranes during synthesis by the use of dodecyl sulfate as counterion. This induces asymetric character not observed in other membranes (9). Alternatively asymetric membranes can be produced by preparing layered structures (Schematic 3). We have prepared such membranes and the asymetric transport properties are shown by the typical results obtained (Figure 4). 

Fig. 12a-c. Schematic representation of the tilted layer structures for the polyphilic molecules in a strongly fractured conformation a the random up-down configuration b polar packing of molecules within the layer c two-dimensional (modulated) polar structure (Blinov et al. [44])... 

Surface force apparatus has been applied successfully over the past years for measuring normal surface forces as a function of surface gap or film thickness. The results reveal, for example, that the normal forces acting on confined liquid composed of linear-chain molecules exhibit a periodic oscillation between the attractive and repulsive interactions as one surface continuously approaches to another, which is schematically shown in Fig. 19. The period of the oscillation corresponds precisely to the thickness of a molecular chain, and the oscillation amplitude increases exponentially as the film thickness decreases. This oscillatory solvation force originates from the formation of the layering structure in thin liquid films and the change of the ordered structure with the film thickness. The result provides a convincing example that the SFA can be an effective experimental tool to detect fundamental interactions between the surfaces when the gap decreases to nanometre scale. 

Fig. 1.—Schematic representation of polymer chains in crystalline poly-(hexamethylene adipamide). Layer structure resulting from association of polar groups is indicated by transverse parallel lines. (From Baker and Fuller, J. Am.

The combination of different analytical techniques offers the possibility for a complete characterization of building materials impregnated with liquid alkyl-alkoxysilanes RSi(OC2H5)3. The results derived from IR, NMR and SIMS spectra can be summarized in the schematic layer structure shown in Figure 5. 

Figure 1. Schematic drawing showing the structure of the trigonal prismatic variety of the metal dichalcogenide structure. Note the structure is not drawn to scale but to emphasize the layered structure of the materials.

Fig. 1 Schematic drawing to show the concept of system dimensionality (a) bulk semiconductors, 3D (b) thin film, layer structure, quantum well, 2D (c) linear chain structure, quantum wire, ID (d) cluster, colloid, nanocrystal, quantum dot, OD. In the bottom, it is shown the corresponding density of states [A( )] versus energy (E) diagram (for ideal cases).

Figure 6 Schematic representation of the layered structure of pyrolitic graphite...

Figure 89 illustrates two different tries at simplified representation of the globin structure. For reference, Fig. 89a shows the hemoglobin /3 chain in stereo. Figure 89b shows the globin structure schematically as two layers of helices with the elements in one layer approximately perpendicular to those in the other layer this can be contrasted with a possible description of the up-and-down helix bundles as two layers with their elements approximately parallel to each other. The perpendicular layers provide a rather successful simple schema for the globin structure, but unfortunately there are no other proteins that can be adequately described as two perpendicular layers of helices. Also, specification of the topology in this scheme is cumbersome, since the chain skips back and forth between layers. 

Schematic depiction of seven-layer structure and basic processes in polymer electrolyte fuel cells under standard operation with hydrogen and oxygen.

Figure 1. Schematic view of the one-dimensional layered structure. The vertical lines denote discontinuities of refractive index distribution. The monochromatic plane wave is incident in the y direction with the electric field amplitude The amplitudes of reflected and transmitted waves are ref and, respectively.

Figure 1. Schematic description of a (lithium ion) rocking-chair cell that employs graphitic carbon as anode and transition metal oxide as cathode. The undergoing electrochemical process is lithium ion deintercalation from the graphene structure of the anode and simultaneous intercalation into the layered structure of the metal oxide cathode. For the cell, this process is discharge, since the reaction is spontaneous.

Fig. 6. a) The layer-structure of an ordered perovskite Sr2(BCr)Os vertical to the hexagonal c-axis (idealized description) b) Schematic illustration of a- and 7t-... 

The basic structures of Tl-compounds are tetragonal body centered layer structures with layers normal to the c-axis. The lattice constants are a = 3.8A, and c - 29.4A (for 2212), 35.4A (for 2223), 22A (for 1245) and so on. The common structural features are Tl-O layers sandwiched by Ba-O sheets and blocks of Cu-O layers separated by Ca intermediate layers. The structures differ from each other by the number of Cu-O layers. For example, the number of Cu-O layers in the 2212 phase is two three in 2223 and five in the 1245 structure. A schematic representation of the 1245 structure is shown in Figure 14. The samples are normally prepared from the component oxides in sealed gold tubes to avoid problems with the toxicity and loss of Tl... 

Figure 6.3. High Tq cuprate superconductors (HTSC) as catalysts (a) structural schematic diagram of YBa2Cu307 ( 123 ) HTSC with Cu02 sheets (b) HRTEM atomic image of the 123 phase in [010] projection with ED pattern. The image is recorded near the Scherzer defocus. The positions of the Y, Ba and Cu atom columns are indicated. The layer separation is "- 1.18 nm and the unit cell is outlined. (After Gai and Thomas 1991.)...

In order to prove the importance of the delaminated layer structure in the direct (melt) intercalation, the intercalation of stearic acid molecules into the clay galleries has been studied by premixing them with organoclay and then successfully incorporating this modified clay into the rubber matrix [59]. A schematic presentation of such modification of clay is given in Fig. 37. 

In the lithium-ion secondary battery, which was put on the market in 1990, the difficulty of the Li+/Li electrode was avoided by use of a carbon negative electrode Cy), which works as a host for Li+ ions by intercalation. The active material for the positive electrode is typically LiCo02, which is layer-structured and also works as a host for Li+ ions. The electrolyte solutions are nearly the same as those used in the primary lithium batteries. A schematic diagram of a lithium-ion battery is shown in Fig. 12.2. The cell reaction is as follows ... 

Figure 28-11 Schematic representation of the layer structure of color film and the color changes that occur on development. The actual film also contains a filter below the blue-sensitive layer to remove the blue light passing through this layer (because all emulsions are sensitive to blue), an antihalation layer below the red to prevent scattering of the light back through the emulsion, and a film base, such as cellulose acetate or poly-1,2-ethanediyl 1,4-benzenedioate, to support the emulsion.

Figure 16. Schematic of the influence of steps on diffusion processes in case d > > W. The lined areas indicate the extension of the depletion layer parallel or perpendicular to the layered structure, WM and W1, respectively, and I denotes the minority carrier diffusion length perpedicular to the layered structure (the horizontal radius of the ellipses is compressed somewhat).

FIGURE 55. Schematic representation of layered structures in (a) kaolinite and (b) kaolinite-DMSO. Dark circles indicate hydrogen atoms. Reproduced by permission of Elsevier Science from Reference 153... 

Figure 14 Inclusion compound of benzyl methyl sulfoxide by 1. (a) Layer structure, (b) Packing (CPK model) and schematic representation of both recognition sites. For clarity, phenyl groups of 1 and guest are unshaded and gray, respectively.

---