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131.
132.
133.
R. Bergmann H. Daniel T. von Egidy F. J. Hartmann H. -J. Pfeiffer 《Zeitschrift für Physik A Hadrons and Nuclei》1977,280(1):27-30
The Coulomb-capture ratios of muons in the metallic solid solutions Au-Ag, Te-Se, Cd-Mg, Nb-V, and Cu-Ni have been measured via the muonic Lyman series intensities. In the case of Nb-V, targets of three stoichiometric ratios were investigated. The results do not agree with the per-atom ratiosA(Z/Z′) assumed to be equal toZ/Z′ (“Fermi-Teller law”) or (Z/Z′)7/6. They are better, but also not in general well, reproduced byA(Z/Z′)=Z 1/3 ln(0.57Z)/[(Z′)1/3 ln(0.57 Z′)], deviations occuring in cases of different metallic radii. 相似文献
134.
E. ühlein Hans H. Pfeiffer P. Kratochvil H. Ringsdorf F. Lohmann W. Eisenmann J. Sunkel E. Gruner E. Best 《Colloid and polymer science》1963,192(1-2):117-122
Ohne Zusammenfassung 相似文献
135.
The behavior of topological solitons in a parallel array of a Josephson junction is studied experimentally. We observe the fusion of two relativistic solitons of the same polarity into a single soliton. The soliton carries two quanta of magnetic flux and, most strikingly, travels 18% faster than an ordinary soliton under the same driving force. We also find a variety of bunched states composed of solitons of the same polarity, moving with fixed separation. 相似文献
136.
W. Pan J.S. Xia D.C. Tsui E.D. Adams L.N. Pfeiffer K.W. West 《Solid State Communications》2006,140(2):88-93
In this paper, we review low temperature electronic transport results in high quality two-dimensional electron systems. We discuss the quantization of the diagonal resistance, Rxx, at the edges of several quantum Hall states. Each quantized Rxx value turns out to be close to the difference between the two adjacent Hall plateaus in the off-diagonal resistance, Rxy. Moreover, peaks in Rxx occur at different positions in positive and negative magnetic fields. All three Rxx features can be explained quantitatively by a ∼1% cm electron density gradient. Furthermore, based on this observation, the well known but still enigmatic resistivity rule, relating Rxx to , finds a simple interpretation in terms of this gradient. In another sample, at 1.2 K, Rxx we observe a strongly linear magnetic field dependence. Surprisingly, this linear magnetoresistance also originates from the density gradient. Our findings throw an unexpected light on the relationship between the experimentally measured Rxx and the diagonal resistivity ρxx. 相似文献
137.
Differential proteome analysis of colon carcinoma cell line SW480 after reconstitution of the tumour suppressor Smad4 总被引:1,自引:0,他引:1
Stühler K Köper K Pfeiffer K Tagariello A Souquet M Schwarte-Waldhoff I Hahn SA Schmiegel W Meyer HE 《Analytical and bioanalytical chemistry》2006,386(6):1603-1612
The tumour suppressor gene Smad4 is frequently inactivated in gastrointestinal carcinomas. Smad4 plays a pivotal role in transducing signals of the transforming growth factor-β (TGF-β) superfamily of proteins. Inactivation
of Smad4 seems to occur late during tumour progression when tumours acquire invasive and metastatic properties. Identification of
proteins directly or indirectly regulated by Smad4 would, therefore, ease the future design of new diagnostic and therapeutic strategies for gastrointestinal carcinoma. We
have used human colon carcinoma cell line SW480 stably transfected with Smad4 as an in-vitro model system to identify Smad4-regulated proteins by applying two-dimensional gel electrophoresis (2DE) then MALDI-PMF/PFF-MS. We identified a total of
47 protein species with a Smad4-dependent expression. From the functions of the candidate proteins we obtained new insights into Smad4’s participation in processes, for example apoptosis, differentiation, and proliferation. 相似文献
138.
Ana Diaz Cristian Mocuta Julian Stangl Mario Keplinger Timm Weitkamp Franz Pfeiffer Christian David Till H. Metzger Günther Bauer 《Journal of synchrotron radiation》2010,17(3):299-307
A study of the coherence and wavefront properties of a pseudo‐channel‐cut monochromator in comparison with a double‐crystal monochromator is presented. Using a double‐grating interferometer designed for the hard X‐ray regime, the complex coherence factor was measured and the wavefront distortions at the sample position were analyzed. A transverse coherence length was found in the vertical direction that was a factor of two larger for the channel‐cut monochromator owing to its higher mechanical stability. The wavefront distortions after different optical elements in the beam, such as monochromators and mirrors, were also quantified. This work is particularly relevant for coherent diffraction imaging experiments with synchrotron sources. 相似文献
139.
We report the observation of a new fractional quantum Hall state in the second Landau level of a two-dimensional electron gas at the Landau level filling factor ν=2+6/13. We find that the model of noninteracting composite fermions can explain the magnitude of gaps of the prominent 2+1/3 and 2+2/3 states. The same model fails, however, to account for the gaps of the 2+2/5 and the newly observed 2+6/13 states suggesting that these two states are of exotic origin. 相似文献
140.
We report the observation of a colossal, narrow resistance peak that arises in ultraclean (mobility ~3×10? cm2/V s) GaAs/AlGaAs quantum wells (QWs) under millimeter wave irradiation and a weak magnetic field. Such a spike is superposed on the 2nd harmonic microwave-induced resistance oscillations (MIRO) but having an amplitude >300% of the MIRO, and a typical FWHM ~50 mK, comparable with the Landau level width. Systematic studies show a correlation between the spike and a pronounced negative magnetoresistance in these QWs, suggesting a mechanism based on the interplay of strong scatterers and smooth disorder. Alternatively, the spike may be interpreted as a manifestation of quantum interference between the quadrupole resonance and the higher-order cyclotron transition in well-separated Landau levels. 相似文献