Series spectra

The X-ray and series spectra,7 and also the /3-ray spectrum of radioactive arsenic,8 have been examined. 

First,one important result of the infrared molecular spectroscopy is a discovery of stationary CO layer in Mira type variable star x Gyg, in which CO lines that stay stationary have been clearly separated from the photospheric CO lines that show cyclic Doppler-shifts by the large amplitude pulsation of the photosphere in time series spectra( Hinkle, Hall, Ridgway, 1982). It was suggested that the stationary CO layer may be located at several stellar radii above the stellar surface, since excitation temperature of the stationary CO layer of x Cyg was found to be 800K. 

D. Gernez, J. Stark and 0. Hardtke, H. Deslandres, and H. Deslandres and A. Kannapeli. J. J. Hopfield, A. Fowler, S. Datta, identified series Spectra. This makes it appear as if the ordinary line spectrum is the spark spectrum of N+ while A. Fowler has suggested that the so-called enhanced lines, obtained by using a powerful stimulus, may represent a second stage in the ionization. 

Accmrate details of these K series spectra of Mo and W wiU be published as soon as the photographs can be examined by means of the new photometer I have designed and am having set up in our new physical research laboratory. 

But if, on the basis of these conceptions and the classical principles, we now attempt to develop a mechanical theory of the atom, we encounter the following fundamental difficulty a system of moving electric charges, such as is pictured in this model, would continually lose energy owing to electromagnetic radiation and must therefore gradually collapse. Further, all efforts to deduce the characteristic structure of the series spectra on the basis of the classical laws have proved fruitless. 

The optical series spectra of the elements provide one of the principal means of obtaining information regarding the structure of... 

Bohr realised that, by purely theoretical considerations and the construction of models, the desired object of explaining the regularities in the structures of atoms (periodic system of the elements) would be very difficult to attain he therefore adopted a procedure by means of which, half theoretically and half empirically, making use of all the evidence provided by physics and chemistry, and, especially, by a thorough application of the data derived from the series spectra, there was evolved a picture of the building up of atoms. 

In 1929 Bonhoeffer and P. Harteck [14] successfully prepared the first pure para-hydrogen sample. In 1931 Urey, Brickwedde and Murphy [15] investigated the visible atomic Balmer series spectra of hydrogen samples and discovered the... 

A method able to classify compounds into various functional categories from their low-resolution mass spectra, similar to the method used by Crawford and Morrison, has been recently proposed by Smith >. A large set of reference spectra is reduced to a correlation set of ion-series spectra . Smith shows that each class of compounds that is available in an archive can be characterized by a typical ion-series spectrum. To determine the class of compounds to which an unknown substance should be assigned, the intensities of the signals found in its low-resolution mass spectrum are summed in the 14 different ion series calculated according to a formula similar to that used by Crawford and Morrison. Smith uses the following equation ... 

This summation pelds the ion-series spectrum for that compound, which is then matched, either manually or automatically, with the ion-series spectra of each class of compounds known to the system. Applications to environmental chemistry and to the analysis of complex geochemical samples seem to have been promising. 

In this case the researchers purchased carbon-13 enriched [l- C]glucose and [6- C]mannose and at time zero mixed each with cell suspensions of the bacteria. The sample was placed directly in an NMR probe and the signals accumulated over 256 repeated scans and the resulting FID were Fourier-transformed. The time series spectra in Figure 7.3 show that the glucose was consumed and converted to [3- C]lacetate (21.1 ppm), [2- C ]-ethanol (17.8 ppm) and lower concentration products not yet observable in the short time span shown. (Note also that the two... 

Ion series spectra are obtained by summing up peaks with a mass difference of 14 ("modulo 14 summed"). Applications of these pattern vectors containing 14 components were investigated by several authors C12, 59, 143, 144, 270, 271, 2833. 

The X-ray spectra of the rare earths are similar to those of all other elements. The spectra consist of only a few lines and absorption edges that result from electronic transitions among the inner-most shells of the atonl. Increases in atomic number cause a simple shift of the X-ray spectrum to higher energies or to lower wavelengths. Consequently, the X-ray spectrum is unique and characteristic for each element. With exciting radiation obtainable from commercially available 50- or 60-kilovolt X-ray tubes, the L series spectra of the lanthanides are readily excited. To excite the K spectra with adequate intensity, 100-kilovolt power supplies are required. Lines from the K series are used for the determination of Sc and Y. For lanthanide analyses, nearly all analysts recommend lines in the L series. 

The libraries used for the SISCOM search are divided into 14 sections of ion series. The assignment of a reference spectrum to one of these sections is based on the strongest peak in the ion series spectrum. Ion series spectra consist of 14 peaks. Each of these peaks (or ion series) represents the sum of all the intensities of the original spectrum and with a mass of m/z modulo 14 = . Thus, for example, the ion series 1 corresponds to the sum of the intensities of the masses 15, 29, 43,... The strongest ion series in the spectrum ofthe unknown substance decides which section of the library is to be used for further searching. As the ion series spectra of related compounds (similar structures) are almost identical (even when the intensity ratios in the spectra differ), the ion series spectra are particularly suitable as a filter for a similarity search. 

Serien-nummer, /. serial number, -schaltung, /. (Elec.) series connection, -schnitt, m. serial section, -spektrum, n. series spectrum, versuch, m. serial experiment or test. Serizin, n. sericin. 

Kumra, S., Jacobsen, L.K., Lenane, M., Smith, A., Lee, P., Malanga, C.J., Karp, B.I., Hamburger, S., and Rapoport, J.L. (1998a) Case series spectrum of neuroleptic-induced movement disorders and extrapyramidal side effects in childhood-onset schizophrenia. J Am Acad Child Adolesc Psychiatry 37 221-227. 

In the Proceedings of the National Academy of Sciences for January, 1932, appears an article in which I describe experiments on the new K series x-ray lines, of which I spoke in a paper presented to the American Physical Society at its New York meeting in February, 1931. The end of the article contains several photometer curves of the doublet, the y line and a few of the new lines belonging to the molybdenum K series spectrum. The photometer now existing in the Jefferson Laboratory produced some of these curves, and for the other curves it gives me great pleasure to thank Dr. DuMond of the California Institute of Technology. 

As stated above the reason for designing this photometer, and for having it constructed and set up, has been to examine in some detail the x-ray K series spectrum in which I have found a number of new lines. The new lines were presented to the Physical Society at the New York meeting in February, 1931. They appear also on the photographs reproduced in the previous article in the January number of the Proceedings of the... 

Professor P. A. Ross of the University of Stanford has recently published two letters in the Physical Review (February 1, and February 15, 1932), in which he mentions some extraordinarily interesting ionization curves representing the K series spectrum of molybdenum. He verifies by these ionization observations the above-mentioned new lines in the K series of molybdenum. He also finds similar lines in the K series of other chemical elements (Tel—Pal—Ag—Cd—Sn— and Sb). Obviously this discovery is of very great importance. The suggestion by Professor Ross... 

E. 0. Hulburt. J. Formanek said that the chromium salts do not react with alkanna tincture. L. de Boisbaudran examined the fluorescence spectrum. According to T. Tanaka, chromium is the principal agent in the cathodoluminescence of corundum. No series spectrum has been observed with chromium, but the lines have been studied from this point of view by L. Janicki, A. Dufour, P. G. Nutting, H. N. Russell, S. Goudsmit, E. Kromer, M. Steenbeck, H. Deslandres,... 

FIGURE 1 Energy-level diagram for the hydrogen atom showing allowed transitions. Insert displays the Balmer series spectrum that can be observed in the visible. 

Bafmer series Frequencies of certain lines in the spectrum of hydrogen are simply related to each other, and can be expressed by a general formula. One group of lines is termed the Balmer series. Other series were later discovered in the spectrum of hydrogen by Lyman, Paschen, Brackett and Pfund. 

Impact Echo -result showing waveform (top), single wave spectrum with peak echoes (middle) and average frequency spectrum for a series of tests at the same point. 

The energy spectrum of the resonance states will be quasi-discrete it consists of a series of broadened levels with Lorentzian lineshapes whose full-width at half-maximum T is related to the lifetime by F = Fn. The resonances are said to be isolated if the widths of their levels are small compared with the distances (spacings) between them, that is... 

In electron spin echo relaxation studies, the two-pulse echo amplitude, as a fiinction of tire pulse separation time T, gives a measure of the phase memory relaxation time from which can be extracted if Jj-effects are taken into consideration. Problems may arise from spectral diflfrision due to incomplete excitation of the EPR spectrum. In this case some of the transverse magnetization may leak into adjacent parts of the spectrum that have not been excited by the MW pulses. Spectral diflfrision effects can be suppressed by using the Carr-Purcell-Meiboom-Gill pulse sequence, which is also well known in NMR. The experiment involves using a sequence of n-pulses separated by 2r and can be denoted as [7i/2-(x-7i-T-echo) J. A series of echoes separated by lx is generated and the decay in their amplitudes is characterized by Ty. ... 

Figure B2.4.5. Simulated lineshapes for an intennolecular exchange reaction in which the bond joining two strongly coupled nuclei breaks and re-fomis at a series of rates, given beside tlie lineshape. In slow exchange, the typical spectrum of an AB spin system is shown. In the limit of fast exchange, the spectrum consists of two lines at tlie two chemical shifts and all the coupling has disappeared.

The tenn slow in this case means that the exchange rate is much smaller than the frequency differences in the spectrum, so the lines in the spectrum are not significantly broadened. Flowever, the exchange rate is still comparable with the spin-lattice relaxation times in the system. Exchange, which has many mathematical similarities to dipolar relaxation, can be observed in a NOESY-type experiment (sometimes called EXSY). The rates are measured from a series of EXSY spectra, or by perfonning modified spin-lattice relaxation experiments, such as those pioneered by Floflfman and Eorsen [20]. 

Hg. 1.14 The connection between the Fourier transform and the Fourier series can be established by gradually increasing the period of the function. When the period is infinite a continuous spectrum is obtained. (Figure adapted from Ramirez R W, 1985, The FFT Fundamentals and Concepts. Englewood Cliffs, NJ, Prenhce Hall.)... 

Procedure. Use Mathcad, QLLSQ, or TableCurve (or, preferably, all three) to determine a value of the ionization energy of hydrogen from the wave numbers in Table 3-4 taken from spectroscopic studies of the Lyman series of the hydrogen spectrum where ni = 1. 

At first, the dimeric nature of the base isolated from 3-ethyl-2-methyl-4-phenylthiazolium was postulated via a chemical route. Indeed the adduct of ICH, on a similar 2-ethylidene base is a 2-isopropylthiazolium salt in the case of methylene base it is an anilinovinyl compound identified by its absorption spectrum and chemical reactivity (45-47). This dimeric structure of the molecule has been definitively established by its NMR spectrum. It is very similar to the base issued from 2.3-dimethyl-benzo thiazolium (48). It corresponds to 2-(3 -ethyl-4 -phenyl-2 -methylenethiazolinilydene)2-methyl-3-ethyl-4-phenylthiazoline (13). There is only one methyl signal (62 = 2.59), and two series of signals (63= 1.36-3.90, 63= 1.12-3.78) correspond to ethyl groups. Three protons attributed to positions T,5,5 are shifted to a lower field 5.93, 6.58, and 8.36 ppm. The bulk of the ten phenyl protons is at 7.3 ppm (Scheme 22). 

Whatever the derivative considered, the nuclear magnetic resonance spectra of thiazoles are remarkably simple and apparently univoque. The first proton NMR spectrum of thiazole was described by Bak et al. (171). It was followed by a series of works establishing a systematic description... 

A typical IR spectrum such as that of hexane m Eigure 13 31 appears as a series of absorption peaks of varying shape and intensity Almost all organic compounds exhibit a peak or group of peaks near 3000 cm due to carbon-hydrogen stretching The peaks at 1460 1380 and 725 cm are due to various bending vibrations... 

We can use the energy level diagram in Figure 10.14 to explain an absorbance spectrum. The thick lines labeled Eq and Ei represent the analyte s ground (lowest) electronic state and its first electronic excited state. Superimposed on each electronic energy level is a series of lines representing vibrational energy levels. 

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