Reconstruction model

Subsequently, Mitchell s group in Vancouver, by means of a tensor-LEED study17 of the Cu (110)-(2 x 3)N surface structure, supported a reconstruction model in which the topmost layer is described as a pseudo-(100)-c(2 x 2)N overlayer with metal corrugation of about 0.52 A in the reconstructed layer. Each nitrogen adatom is almost coplanar with the local plane formed by the four neighbouring copper atoms. Of the four N atoms present in the unit mesh, three are also bonded to Cu atoms in the layer below and therefore are five coordinate. 

J. P. Tiefenbacher, R. R. Hagelman, R. J. Cecora 2000, California Citrus Freeze- of December 1998 Place, Perception and Choice - Developing a Disaster Reconstruction Model, Quick Response Report 125, James and Marilyn Lovell Center for Environmental Geography, San Marcos, TX. 

A qualitative structural model of the reconstructed c(2 x 2) W(1(X)) surface was first proposed by Debe and King on the basis of symmetry arguments. Figure 39 shows this reconstruction model. The surface atoms exhibit only inplane displacements along diagonal directions. A subsequent LEED structure analysis of Barker et al. ° supported this picture. In a more recent quantitative LEED analysis, Walker et a/ deduced a lateral displacement of 0.16A at 200K. 

They found a whole bunch of soft phonons, which are primarily horizontally polarized, near the zone boundaries between M and X. The most unstable mode they observed is the Mj phonon, the displacement pattern of which is shown in Fig. 40 note the similarity between this pattern and the reconstruction model in Fig. 39. According to Wang and Weber, these soft phonons are caused by electron-phonon coupling between the surface phonon modes and the electronic 3 surface states at the Fermi surface. They attributed the predominant Ms phonon instability to an additional coupling between d(x — y ) and d(xy) orbitals of the Zj states. 

Detailed description of a porous microstructure is an essential prerequisite for unveiling the influence of pore morphology on the underlying two-phase behavior. This can be achieved either by 3-D volume imaging or by constructing a digital microstructure based on stochastic reconstruction models. Non-invasive techniques, such as X-ray micro-tomography, are the popular methods for 3-D... 

The reconstruction of individual structures can be a model for the development of individual cells, but not for multicellular systems such as embryos. In this case, a model must be capable of performing in parallel a plurality of reconstructions, while taking into account a variety of interactions between individual structures. What must be simulated is an increase of information between initial and final structures, and on this point the reconstruction model is crystal clear. The difference between initial and final information, and therefore the overall increase of complexity in the system, is entirely dependent on the memories which are used in a reconstruction, because it is only in the memory space that new information appears. 

These examples show that the two strategies proposed by the reconstruction model do indeed correspond to two developmental strategies that have both been exploited by nature. The model is capable therefore of simulating some important characteristics of... 

We have already seen that the reconstruction model makes a sharp distinction between real-space matrices and memory-space matrices, and suggests that embryos too have equivalent types of three-dimensional structures the real structures of the phenotypic body, and the memory structures of the body plan. According to the reconstruction model, therefore, during embryonic development there is not only a development of phenotypic structures, but also a parallel development of memory structures. It should be noticed, however, that these two processes are sharply asymmetrical. 

The phenotypic development of a body is practically a continuous process, while the development of contextual information is divided into two very different phases by the discontinuity of the body plan. In the first period, when the body plan does not exist, there is contextual information only at the cell level, and memory structures are confined to the cell. In the second phase, in contrast, the body plan becomes a source of contextual information above the cell level, and the embryo s development takes place in a totally new reference system. From this moment on, the body plan becomes a new intermediary between genotype and phenotype, and since it is shared by all members of a phylum, we can call it the phylotype, or the phylotypic body. The reconstruction model, in short, allows us to conclude that a multicellular organism consists of three fundamental categories - genotype, phylotype and phenotype - and that embryonic development consists of two different developments which come one after the other, i.e. in series. The first is the development of the phylotypic body the second is the development of the individualko y. 

Ti(>2 is a basic and simple material, and more than thirty years have passed since the discovery of the Ti(>2 photocatalytic reaction. The wettability of solid surfaces is also a basic and familiar property. It is amazing that the excellent characteristics (high hydrophilicity among other properties) of the already well understood TiC>2 were discovered only recently. In this paper, we introduced the surface reconstruction model of hydroxyl groups as the mechanism for the highly hydrophilic conversion. However, areas for further research still remain. 

Another model that involves subsurface oxygen was developed by Vish-nevskii for Pt(lOO) (60,70,71). The mathematical formulation, though developed independently, is very similar to that of Bassett and Imbihl, and is also a hybrid between Eigenberger-type models and coverage-dependent activation energy models. This model, however, is in conflict with a surface reconstruction model developed by Ertl et al., which will be discussed later. 

The possibility of diamond surface reconstruction without hydrogen termination has been discussed in Ref [461] based on an analogy with Si and Ge. The surface reconstruction models are Hanemann s (111) 2x1 buckling model [462], Tandy s (111) 2x1 model, Pandy s jr-bonded model [463], and Chadi s rr-bonded (111) 2 X 1 model [464]. It was suggested that the buckling and 7t-bonded structures are in equilibrium at temperatures above 1000 °C. In Ref [465], a reconstruction from an H-terminated (111) 1 x 1 to an H-free (111) 2 x 1 structures after heating at 1000 °C is described. 

Figure 22 Ni(001)c(2 x 2)-0. (a) Fourfold co-ordination non-reconstructed model, (b) Shadowing effects of O on Ni atoms along the (4l0) azimuth, (c) Scattered intensities for 1 keV incidence in (4T0) azimuth (Reproduced by permission from Surface Sci., 1976, 54, 519)...

A. Reconstructed model B. Top view C. Cut away view of model... 

Below we will discuss, as an example, only a reconstruction model for CO oxidation developed by Ertl and co-workers. 

Fig. 30. Possible structural model for the Si(l 11)5x2-Au reconstruction. Model includes four gold atom sites per 5x2 unit cell forming two gold rows. Not yet clear is whether there is a fifth, partially occupied gold site which may appear as protrusion in STM images. Alternatively, this protrusion is ascribed to the Si adatoms. Both are shown in figure. Si atom density is 1.5 ML which is slightly higher than the value of 1.1-1.3 ML determined by REM [90T]. Au atoms are shown in black and Si atoms in white. 5x2 unit cell is outlined. [95M3, 97P3].

The data set is linearly divided into a training set Xtjuv of NfgN = 8000 samples used for building the PCA reconstruction models and a test set Xtst of NfsT = 4713 samples for computing the ensemble reconstruction performances (Eqs. 4, 5). Notice that the transients related to the first outage are included in Xtrn, while those of the second outage are in Xtst-... 

Raghavan, M. L., Vorp, D. A., Federle, M. P., Makaroun, M. S., and Webster, M. W. (2000), Wall stress distribution on three-dimensionally reconstructed models of human abdominal aortic aneurysm, /. Vase. Surg. 31 760-769. 

The role of phosphoinositides has been thoroughly described in many signaling and membrane trafficking events but their function as modulators of membrane structure and dynamics in membrane fusion has not been studied. Researchers have reconstructed models that mimic the component of nuelear envelope precursor membranes with naturally elevated amaounts... 

B.P. Geiser, Reconstruction Models , Workshop on Atom Probe Tomography, Blue Mountains, NSW, Australia, 2008. 

Vehicle accident reconstruction models allow analysis of what happened in the sequence of events before, during and after collision. The models depend on accurate information about particular automobiles and data from crash sites. Chapter 14 introduced accident reconstruction modeling. 

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