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71.
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
72.
A. Müller W. Plass E. Krickemeyer S. Dillinger H. Bögge A. Armatage C. Beugholt U. Bergmann 《Monatshefte für Chemie / Chemical Monthly》1994,125(5):525-533
Summary The X-ray crystal structure of the compound Na3(NH4)12[Mo57Fe6(NO)6O174(OH)3(H2O)24]·76H2O (3) [P63/mmc;a=2380.6(5),c=2763.4(7),Z=2], the giant cluster anion of which has the shape of a doughnut, shows remarkable details: The cluster [{Fe(H2O)2}6{Mo(-H2O)2(-OH)Mo}3{ Mo15(MoNO)
2
3+
O58(H2O)2}3]15– can be described as being composed of three transferable {Mo17} ligands bridged by cationic centers and contains a novel nanodimensional central cavity. 相似文献
73.
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
74.
Mechanical Behavior of Polymer Gels for RDCs and RCSAs Collection: NMR Imaging Study of Buckling Phenomena
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Erich Hellemann Dr. Rubens R. Teles Prof. Dr. Fernando Hallwass Prof. Dr. W. Barros Jr. Dr. Armando Navarro‐Vázquez Prof. Dr. Roberto R. Gil 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(46):16632-16635
Anisotropic NMR parameters, such as residual dipolar couplings (RDCs), residual chemical shift anisotropies (RCSAs) and residual quadrupolar couplings (RQCs or ΔνQ), appear in solution‐state NMR when the molecules under study are subjected to a degree of order. The tunable alignment by reversible compression/relaxation of gels (PMMA and p‐HEMA) is an easy, user‐friendly, and very affordable method to measure them. When using this method, a fraction of isotropic NMR signals is observed in the NMR spectra, even at a maximum degree of compression. To explain the origin of these isotropic signals we decided to investigate their physical location inside the NMR tube using deuterium 1D imaging and MRI micro‐imaging experiments. It was observed that after a certain degree of compression the gels start to buckle and they generate pockets of isotropic solvent, which are never eliminated. The amount of buckling depends on the amount of cross‐linker and the length of the gel. 相似文献
75.
Thermal fluctuations of surfactant bilayers in an aqueous solution produce an effective, long-range repulsion that can lead to a continuous unbinding transition. We report on an optical interferometry study of the thermal fluctuations of multicomponent bilayers close to the unbinding transition. We find that, in contrast to the case of single-component bilayers, the thermal fluctuation spectrum of multicomponent bilayers does not agree with a continuous unbinding transition but instead indicates the proximity of an unbinding tricritical point. 相似文献
76.
We consider the condensate wave function of a rapidly rotating two-component Bose gas with an equal number of particles in each component. If the interactions between like and unlike species are very similar (as occurs for two hyperfine states of (87)Rb or (23)Na) we find that the two components contain identical rectangular vortex lattices, where the unit cell has an aspect ratio of sqrt[3], and one lattice is displaced to the center of the unit cell of the other. Our results are based on an exact evaluation of the vortex lattice energy in the large angular momentum (or quantum Hall) regime. 相似文献
77.
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
78.
Self-stabilized passive, harmonically mode-locked stretched-pulse erbium fiber ring laser 总被引:7,自引:0,他引:7
We have studied a passive, harmonically mode-locked stretched-pulse erbium fiber ring laser with net positive dispersion that is self-stabilized by gain depletion and electrostriction. Periodic pulses with supermode suppression of >75 dB and picosecond jitter are achieved. The pulses are compressible to 125 fs by external chirp compensation. The repetition rate is 220 MHz, and the average power is as high as 80 mW. 相似文献
79.
80.
Müller A Polarz S Das SK Krickemeyer E Bögge H Schmidtmann M Hauptfleisch B 《Angewandte Chemie (International ed. in English)》1999,38(21):3241-3245
A novel exchange between ligands and/or guest molecules can be accomplished in giant molecular spheres (an example is shown in the picture) which are in equilibrium with the corresponding giant baskets in solution. 相似文献