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Absolute position

In Figure 1, we see that there are relative shifts of the peak of the rotational distribution toward the left from f = 12 to / = 8 in the presence of the geometiic phase. Thus, for the D + Ha (v = 1, DH (v, f) - - H reaction with the same total energy 1.8 eV, we find qualitatively the same effect as found quantum mechanically. Kuppermann and Wu [46] showed that the peak of the rotational state distribution moves toward the left in the presence of a geometric phase for the process D + H2 (v = 1, J = 1) DH (v = 1,/)- -H. It is important to note the effect of the position of the conical intersection (0o) on the rotational distribution for the D + H2 reaction. Although the absolute position of the peak (from / = 10 to / = 8) obtained from the quantum mechanical calculation is different from our results, it is worthwhile to see that the peak... [Pg.57]

We conclude that the absolute position of the node on the map to which the sample pattern points is not important neither of the maps in Figure 3.14 and Figure 3.15 is better than the other. It is the way that samples are clustered on the map that is significant. It is, in fact, common to discover when using a SOM that there are several essentially equivalent, but visually very different, clusterings that can be generated. [Pg.71]

Defect levels typically contain both valence- and conduction-band character. If the relative position of these bands is inaccurate, the position of the defect level will also be uncertain. We thus see that, at this point in time, none of the theoretical methods is able to make accurate predictions for positions of defect levels in the band gap. However, it should be noted that, while the absolute position of defect levels is uncertain, their relative motion induced by displacements of the impurity or by changes in the charge state is quite reliable. These observations generally allow the derivation of reliable qualitative conclusions about defect levels, such as deep... [Pg.609]

The signs of geminal, F H coupling-constants (in contrast to those of geminal, iH-1H coupling-constants) are absolutely positive. They were determined for derivatives of glycopyranosyl fluorides, 75,292,293 2-deoxy-2-fluoro-D-gluco- and -manno-pyranosyl fluorides,71... [Pg.262]

Absolutely, positively, check that you are bubbling the same line on the answer sheet as the question you are answering. I suggest that every time you turn the page you double check that you are still lined up correctly. [Pg.36]

Chemists define the total internal energy of a substance at a constant pressure as its enthalpy, H. Chemists do not work with the absolute enthalpy of the reactants and products in a physical or chemical process. Instead, they study the enthalpy change, AH, that accompanies a process. That is, they study the relative enthalpy of the reactants and products in a system. This is like saying that the distance between your home and your school is 2 km. You do not usually talk about the absolute position of your home and school in terms of their latitude, longitude, and elevation. You talk about their relative position, in relation to each other. [Pg.222]

Relative partial molar enthalpies also can be visualized in terms of a diagram, such as Figure 18.4. Although the absolute position of or on the enthalpy scale cannot be specified, the difference between them can be determined. [Pg.414]

Korner s method org chem A method for determining the absolute position of substituents for positional isomers in benzene by the experimental production of positional isomers from a given disubstituted benzene. kor-norz, meth-3d ... [Pg.210]

The curvature itself can be quite easily measured by translating the specimen a distance x in its plane along a diameter (a circular wafer is assumed), repeating the measurement and noting the shift in the absolute position of the Bragg peak. Then, again,... [Pg.62]

Vicinal Coupling, V ( H, F). The signs of vicinal couplings were found to be absolutely positive, and their angular dependence parallels" that of proton-proton coupling-constants, - ranging between 0 and... [Pg.75]

Developed method of two-step centrifugation of cells enables the isolating up to 95% of CD 45 - cells and up to 97% of CD 34 -cells from cord blood (Fig. 1). It is worth of noting that ficoll causes the losses in the number of isolated cells (up to 55%). Therefore ficoll use to isolate cells is not absolutely positive. [Pg.229]

Table 10.2 Relative and absolute positional relationships, symmetry and number of possible formation pathways oftrisadducts that can be formed out of e and trans-n [n = 1-4) bisadducts (first row) neglecting cis additions. Table 10.2 Relative and absolute positional relationships, symmetry and number of possible formation pathways oftrisadducts that can be formed out of e and trans-n [n = 1-4) bisadducts (first row) neglecting cis additions.
The effect of the extra ir-bond in 64qx 70qx i remarkably small. The rather high Ksem s as the absolute positions of Ei and E2 correspond to those of... [Pg.34]

The carriers can move the sample in any horizontal direction through a sequence of two steps. First, the carriers moves quickly downwards, to the right, then upwards. During this step, the absolute position of the sample is frozen by its inertia. Second, the carriers then move slowly to the left, recovering their original position. The sample follows the motion of the carriers because of friction. By repeating these two steps, the sample can be moved in any direction, by steps of 50 to 1500 A, up to a few millimeters. [Pg.276]

We can choose as 37V-6 coordinates any set which are independent of the absolute position and orientation of the nuclei in space. In practice the most convenient coordinates will consist of internuclear distances or bond angles, but there is no unique choice and one must consider the convenience for the particular problem in hand. We will illustrate this in two cases. [Pg.100]

To define the economic performance of a manufacturing venture, an analyst must predict various sources and sinks of money throughout the lifetime of a project. In fact the investors invest a huge amount of money when they begin to build the chemical plant, but they will earn money from sales only when the plant is finished and operating. Owing to inflation and devaluation, future money is different from present money [13,15], Therefore, a future income needs to be discounted to its present value in order to evaluate the expected profitability of a chemical plant. Of course, when dealing with future events, nobody can be absolutely positive about prices, inflation rates, etc. Therefore many assumptions need to be... [Pg.469]

CRYSTAL (Homometric Pairs). Two crystal structures having the same x-ray diffraction pattern. This is possible because, basically, a diffraction pattern depends only on the relative vector distances between the atoms in the lattice, not on their absolute positions in space. [Pg.461]

An initial series of measurements concerned the accurate determination of the dilution factor. As is represented in Fig.5.16, the absolute position of the tubes of the process solution and of the sodium hydroxide solution over the rollers of the pump is different. One tube is situated higher on the roller than the other, which can lead to a small difference in flow rate. By determining the hydrogen peroxide concentration by means of titration of a sample taken from the bath and a sample taken at the exit of the detection cell (diluted solution), the dilution factor can be determined. Table 5.1 presents the results of 23 measurements of the hydrogen peroxide concentration, performed at a liquid flow rate of 11/h. It is concluded that the dilution factor equals 1.9773+0.0014, which in fact is very close to 2. [Pg.156]

The frequency of the amide I peak observed in the lens is sensitive to protein secondary structure. From its absolute position at 1672 cm-1, which is indicative for an antiparallel pleated 3-sheet structure, and the absence of lines in the 1630-1654 cm-1 region, which would be indicative of parallel (1-sheet and a-helix structures, the authors could conclude that the lens proteins are all organized in an antiparallel, pleated 3-sheet structure [3]. Schachar and Solin [4] reached the same conclusion for the protein structure by measuring the amide I band depolarization ratios of lens crystallins in excised bovine lenses. Later, the Raman-deduced protein structure findings of these two groups were confirmed by x-ray crystallography. [Pg.289]

Um, but for all it s worth, with a litde help from Fitz I managed to break free. Threw this Vorman off, but then he went for his gun. But - and this is the really strange part - I m positive, absolutely positive he didn t get a shot off before this circle of fire just erupted all around the Doctor and the other chap as they were wrestling around, smashing into the display cabinets and everything. ... [Pg.20]

To obtain the dynamic hysteresis loop of a ferroelectric capacitor the polarization is measured versus the applied voltage. Since the hysteresis is neither a linear nor a time invariant property, the hysteresis loop is dependent on the sample history and on the measurement method. To have a standardized and comparable hysteresis loop, certain parameters are commonly fixed. One is the absolute position of the loop on the polarization axis, since the initial (virgin) state of the polarization is unknown in almost all cases, the hysteresis loop is balanced to a reference value. Most commonly the positive and negative saturation polarization are set to... [Pg.59]

In a collision process, it is the relative position of the atoms that matters, not the absolute positions, when external fields are excluded, and the potential energy E will depend on the distances between atoms rather than on the absolute positions. It will therefore be natural to change from absolute Cartesian position coordinates to a set that describes the overall motion of the system (e.g., the center-of-mass motion for the entire system) and the relative motions of the atoms in a laboratory fixed coordinate system. This can be done in many ways as described in Appendix D, but often the so-called Jacobi coordinates are chosen in reactive scattering calculations because they are convenient to use. The details about their definition are described in Appendix D. The salient feature of these coordinates is that the kinetic energy remains diagonal in the momenta conjugated to the Jacobi coordinates, as it is when absolute position coordinates are used. [Pg.77]

The L (R) matrix is chosen such that the matrix L (R)TF L (R) = Q (R) is diagonal with elements iv. The eigenvectors of F are arranged as columns in the L (R) matrix. It should also be noticed that V B sol(S (R), R) can no longer be written as a sum of an intramolecular (gas-phase potential) and an intermolecular part as in Eq. (10.18), because the harmonic expansion of the potential around the saddle point is based on the total potential energy surface and not just on the intramolecular part. By combining Eqs (10.19), (10.21), and (10.23) we see that the absolute position coordinates of the atoms in the activated complex around the saddle point of the total potential energy surface can be written as... [Pg.250]

It is often useful to transform from simple Cartesian coordinates to other sets of coordinates when we study collision processes including chemical reactions. In a collision process, it is obvious that the relative positions of the reactants are relevant and not the absolute positions as given by the simple Cartesian coordinates. It is therefore customary to change from simple Cartesian coordinates to a set describing the relative motions of the atoms and the overall motion of the atoms. For the latter motion the center-of-mass motion is usually chosen. In the following we will describe a general method of transformation from Cartesian coordinates to internal coordinates and determine its effect on the expression for the kinetic energy. [Pg.329]


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See also in sourсe #XX -- [ Pg.189 , Pg.190 , Pg.190 , Pg.191 ]




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