INDEX pattern

The refractive indices before and after photoirradiation were measured for a series of mesoionic compounds including 3-phenyl-l,2,3,4-thiatriazolium-5-thiolate. The knowledge of these data allows controlling the optical properties of polymers. The results obtained in <2002MI2290> suggest the applicability of photoelimination of 3-phenyl-l,2,3,4-thiatriazolium-5-thiolate to make various refractive index patterns for polymeric film. It has also been shown that the refractive index changes of mesoionic compounds are proportional to the number of sulfur atoms in the mesoionic skeletons. 

Electron Microdiffraction. Spence and Zuo, 1992. Contains well-dociunented Fortran listings for programs to simulate CBED patterns by Bloch Wave method, and multislice. Indexed patterns shown with HOLZ to speed indexing. 

Day, M. S., Lebow, Irving, Am. Documentation 11, 120-7 (April 1960). New indexing pattern for Nuclear Science Abstracts. 

For reasons to be discussed in Chap. 11, the observed values of sin 6 always contain small systematic errors. These errors are not large enough to cause any difficulty in indexing patterns of cubic crystals, but they can seriously interfere with the determination of some noncubic structures. The best method of removing such errors from the data is to calibrate the camera or diffractometer with a substance of known lattice parameter, mixed with the unknown. The difference between the observed and calculated values of sin 6 for the standard substance gives the error in sin 9, and this error can be plotted as a function of the observed values of sin 6. Figure 10-1 shows a correction curve of this kind, obtained with a particular specimen and a particular Debye-Scherrer camera. The errors represented by the ordinates of such a curve can then be applied to each of the observed values of sin 0 for the diffraction lines of the unknown substance. For the particular determination represented by Fig. 10-1, the errors shown are to be subtracted from the observed values. 

INDEXING PATTERNS OF NONCUBIC CRYSTALS (GRAPfflCAL METHODS)... 

Indexing patterns of noncubic crystals (graphical methods) 335... 

If M is the square matrix of Miller indices, A is the vector of the unknown Aij and L is the vector of Q/, / for the basis lines, each trial set of [Aij in Equation (8) is obtained by solving the system of linear equations MA = L. The correctness of the trial parameters [Ay] is related to the accuracy of low-order lines. Testing several different combinations of the basis lines can enable one to find a correct solution even in the case of error in one or more of the basis lines. A plausible solution is found if the indexed pattern is characterized by M20 > 10 with no more than one unindexed line among the first 20. 

Electron diffraction patterns recorded by tilting a crystal of niobium, Nb, which has the cubic A2 structure (see Chapter 1) with a = 0.3300 nm, are reproduced in the figure below. Using the partly indexed pattern, (a) complete the indexing (b) determine XI for the microscope (c), index the remaining patterns. [Note that not every lattice point will be present on these patterns, see Section 6.9. It may be helpful to determine first of all which reflections will be present using Table 6.8.]... 

Masuda A.,-1962, Regularities in variation of relative abundances of lanthanide elements and an attempt to analyse separation-index patterns of some minerals. J. Earth Set. Nagoya f/nm, 10, 173-187. 

These mirrors may be regarded as one-dimensional holograms that are generated when a chirped and an unchirped laser pulse from opposite directions are superimposed in a medium where they generate a refractive index pattern proportional to their total intensity [693]. When a chirped pulse is reflected by such a hologram, it becomes compressed, similar to the situation with phase-conjugated mirrors. 

Let us mention a few more capabilities created in this growing field. Laser-induced reorientation of the optical axis is possible in PLC combs optically induced trans—cis isomerization occurs. Erasable holograms can be created in PLC materials—as discussed by Eich and Wendorff [100] and pursued since by many. The mbbing of a polymer leads to an anisotropic surface morphology, since the LC molecules become aligned [101]. Scanning force microscopy can be used to create in a controlled way areas with a similar anisotropy and with a desired refractive index patterns. 

Adding fluorescent molecules to photopolymers also provides a method for optical data storage. In such a system, the fluorescent molecules bond to the polymer matrix and become more concentrated in the polymerized regions causing the required refractive index pattern (194). 

The high vertical resolution of ellipsometry is not matched by the achieved lateral resolution. The upper limit is given by diffraction and on the order of the wavelength of light. Recently an experiment has been described which overcomes the diffraction limit and allows a direct visualization of refractive index patterns with a much finer resolution... 

In characterizing HTC, X-Ray Diffraction is a very useful and reliable technique for indexing patterns of phases leading to phase identification in the corrosion product known as surface scale. In fact, this high temperature phenomenon is different from the mst layer formation (in the presence of moisture) since it virtually occurs in dry gaseous environments or molten salts, hi certain cases, HTC may be an internal oxidation process when oxygen diffusion is faster than the surface oxidation rate. 

Table 17.2 gives important time-series models that are commonly encountered in industrial process control, including statistical process control applications (see Chapter 21). Stationary disturbance models (a) and (b) have a fixed mean that is, the sums of deviations above and below the line are equal to zero, but case (a) rarely occurs in industrial processes. Nonstationary disturbance models (c) and (d) do not have a fixed mean but are drifting in nature. Case (c), so-called random walk behavior, is often used to describe stock market index patterns. Case (b) is called an autoregressive... 

Figure 6 RHEED and indexed patterns for BP (111) plane with incident beam along the [112] and [110] azimuth of BP. (From Ref. 45.)...

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