TRANSFORM process, display converter

The reaction of cycloheptatriene with 2,S-dimethyl-3,4-diphenylcyclopentadienone is typical for this class of compounds, resulting in the formation of six distinct products. Equation (5) displays the major products of interest, which include a modest quantity of the exo [6 -i- 4] adduct (82). The mechanistic details of this process were gleaned from monitoring an equimolar mixture of the two reactants maintained at 120 C. This experiment revealed that both the [2 -I- 4] adduct (83) and the [6 + 4] adduct (82) were formed from the outset of the reaction. However, adduct (83) was subsequently converted quantitatively into the [4 -I- 2] cycloadduct (84) via a Cope rearrangement. This interconversion is reminiscent of a similar transformation in the tropone-diene series (see Section 5.2.2.1.1 and ref. 24). 

At ordinary pressure sihcon displays the coordination number of four towards oxygen in most of the silicate structures. The transformation of SiOj into an octahedral arrangement is another example for the functional interpretation of the pressure-distance paradox. Coesite (coordination number = 4) is converted into stishovite (rutile-type, coordination number = 6) at > 100 kbar and > 1200 °C (7, 8). By this process both of the homonuclear distances are decreased, namely the Si—Si distances ( intermolecular ) from 301 pm to 267 pm, which is close to that in oxygen-free K4Si4 (Si—Si distance = 246 pm (55) as well as the O—0-distances ( intermolecular ) from 263 pm to 251 pm. On the other hand the Si—O bond lengths are increased by 10.2% from 161.3 pm to 177.8 pm (79). The latter is overcompensated by the shortening of the Si-Si- and O—0-distances and hence the density is increased by 46.1 % from 2.93 to 4.28 g/cm. ... 

The detector of a mass spectrometer converts the intensity of the ion beam into an electronic signal that can be transformed by the processor into useful formats for storage or display. The intensity of the ion beam and thus of the signal is determined by the number of the ions of a given m/z that reach the detector. A common way to display the processed information is as a mass spectrum, in which the intensity of the signal is displayed as a function of the m/z of the ions arriving at the detector (Fig. 8.59). From such a display, molar mass and, in some cases, structural features can be determined. 

After a time Tr measured from the beginning of the selective excitation pulse, the process is repeated for a total of M cycles, each of which uses a different value for the phase-encoding gradient. After this process is complete, a. My. N array of digitally sampled data is available in the computer memory. This data can be converted by a two-dimensional Fourier transform technique into M y N pixel brightness numbers. These numbers can be displayed as an image, which can be viewed either on a cathode ray tube or as a hardcopy on film. 

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