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61.
Erich Zobetz 《Crystal Research and Technology》1994,29(3):379-385
A new theorem on homometric polytypes is presented. Examples of homometric close-packed structures and MX2-polytypes are given. The method derived may be used to construct homometric n-tuplets by means of decomposition procedures. 相似文献
62.
Erich R. Bagge 《Fortschritte der Physik》1994,42(1):95-100
At a summary of the four present measurements for the solar neutrino problem one receives for the quotient of the number of the really observed events and the theoretically by the standard solar model exspected value the result This says that in the mean only 33.25% with a possible mistake of 19.25% of the exspected solar neutrinos have been observed. If one goes out from the assumption, that the attempts hitherto proposed for the solution of the problem on the solar neutrino deficits as to be regarded as very unsatisfactory on the one side, while on the other the neutrinos of the β-decay may not exist at all, this looks very troublesome. But there is another possibility of a new interpretation. One has to consider, that in connection with each theoretically until now assumed neutrino of β-decay at the solar p-p- and all joined following fusion -processes precisely one positron will be produced. Exactly this particle will with the probability 1/2 in a triplett state of fixing with an electron of the solar centre plasma at a binding energy of −2029.7 eV create an electric-neutral duotron. This particle assumes fully, inclusive the very welcome factor 1/2, the rǒle of the theoretically dispensable neutrino. This can be regarded as the solution of the solar neutrino-problem. 相似文献
63.
Research supported in part by NSERC Canada grant A7251. 相似文献
64.
Svetlana V. Kirpichenko Bagrat A. Shainyan Erich Kleinpeter 《Journal of Physical Organic Chemistry》2012,25(12):1321-1327
The conformational analysis of the first representative of the Si‐alkoxy substituted six‐membered Si,N‐heterocycles, 1,3‐dimethyl‐3‐isopropoxy‐3‐silapiperidine, was performed by low‐temperature 1H and 13C NMR spectroscopy and DFT theoretical calculations. In contrast to the expectations from the conformational energies of methyl and alkoxy substituents, the Meaxi‐PrOeq conformer was found to predominate in the conformational equilibrium in the ratio Meaxi‐PrOeq : Meeqi‐PrOax of ca. 2 : 1 as from the 1H and 13C NMR study. The thermodynamic parameters obtained by the complete line shape analysis showed that the main contribution to the barrier to ring inversion originates from the entropy term of the free energy of activation. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
65.
Low-noise operation of a 9-GHz hybridly mode-locked laser diode is demonstrated. The integrated timing jitter was 47 fs (10 Hz to 10 MHz) and 86 fs (10 Hz to 4.5 GHz), with a pulse width of 6.7 ps. The noise performance as a function of filter bandwidth and oscillator noise is also addressed. 相似文献
66.
Meccanica - In this paper the effect of grain fragmentation of a cohesionless granular material on the change of microstructure quantities is investigated using a micropolar continuum model. To... 相似文献
67.
68.
S?ren Diegelmann Vanessa Nieratschker Ursula Werner Jürgen Hoppe Troy Zars Erich Buchner 《BMC neuroscience》2006,7(1):76
Background
Synapsins are abundant synaptic vesicle associated phosphoproteins that are involved in the fine regulation of neurotransmitter release. The Drosophila member of this protein family contains three conserved domains (A, C, and E) and is expressed in most or all synaptic terminals. Similar to mouse mutants, synapsin knock-out flies show no obvious structural defects but are disturbed in complex behaviour, notably learning and memory. 相似文献69.
Bagrat A. Shainyan Elena N. Suslova Erich Kleinpeter 《Journal of Physical Organic Chemistry》2011,24(12):1188-1192
4,4‐Dimethyl‐4‐silathiane and its S‐oxides [n = 0 ( 1 ), 1 ( 2 ), 2 ( 3 )] were studied experimentally by variable temperature dynamic NMR spectroscopy down to 103 K and the frozen ring inversion was revealed for all three compounds. The barriers for the degenerate ring inversion in 1 and 3 were measured to be 4.8 and 5.0 kcal/mol at the coalescence temperatures of 111 and 116 K, respectively, and practically coincide with the calculated barriers of 4.60 kcal/mol in 1 and 4.46 kcal/mol in 3 . The frozen equilibrium mixture 2‐ax/2‐eq contains 37% of the 2‐ax and 63% of the 2‐eq conformer. The ring inversion barrier proved to be ca. 4.8 kcal/mol. Calculations at the B3LYP/6‐311+G(d,p) level of theory showed the 2‐ax conformer to be 0.90 kcal/mol more stable than the 2‐eq conformer in the gas phase whereas in solution the relative stability of the conformers calculated using the PCM model at the same level of theory is inverted to become 0.19 (in CHCl3) or 0.36 kcal/mol (in DMSO) in favor of the 2‐eq conformer. The chair–chair interconversion mechanism of sulfoxide 2 includes two intermediate energetically equivalent 1,4‐twist forms and the 2,5‐boat transition state: 2‐ax (chair) ? 2 (1,4‐twist) ? [ 2 (2,5‐boat)]≠ ? 2 (1,4‐twist) ? 2‐eq (chair). The calculated ring inversion barriers are 5.1 ( 2‐ax → 2‐eq ) and 4.2 kcal/mol ( 2‐eq → 2‐ax ) in the gas phase, and 4.03 and 4.22 kcal/mol, respectively, in chloroform. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
70.
Elisabeth Eidenberger Erich Stergar Harald Leitner Peter Staron Jürgen Spitaler Claudia Ambrosch-Draxl Helmut Clemens 《Applied Physics A: Materials Science & Processing》2009,97(2):331-340
Atom probe tomography (APT) measurements were conducted to analyze nm-sized precipitates in a Fe-25 m% Co-15 m% Mo model alloy.
Calculation of isoconcentration surfaces and application of cluster-search algorithms yielded the chemical compositions of
matrix and precipitates. Small-angle neutron scattering (SANS) was performed in order to calculate the ratio of magnetic to
nuclear scattering. This so-called A-ratio was compared with values calculated from the chemical information derived from the atom probe data. For this, the magnetism
of the precipitates has to be taken into account. Ab-initio studies have been carried out to determine the magnetic moment
of the precipitate phase. The results show that the extremely fine precipitates are ferromagnetic and exhibit near-equilibrium
composition. In the very early stage of decomposition, however, the composition is different from near-equilibrium. The influences
of the magnetism of the precipitates as well as of artifacts from atom probe measurements on the obtained results are discussed. 相似文献