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91.
Fleischer A Wörner HJ Arissian L Liu LR Meckel M Rippert A Dörner R Villeneuve DM Corkum PB Staudte A 《Physical review letters》2011,107(11):113003
We study electron correlation in sequential double ionization of noble gas atoms and HCl in intense, femtosecond laser pulses. We measure the photoelectron angular distributions of Ne+ relative to the first electron in a pump-probe experiment with 8 fs, 800 nm, circularly polarized laser pulses at a peak intensity of a few 10(15) W/cm2. Using a linear-linear pump-probe setup, we further study He, Ar, and HCl. We find a clear angular correlation between the two ionization steps in the sequential double ionization intensity regime. 相似文献
92.
Magdalena Ulmeanu Iuliana Iordache Mihaela Filipescu Valentin Craciun Simona Cinta Pinzaru Andreas Hörner 《Central European Journal of Physics》2011,9(5):1280-1287
Experimental studies on patterning hexagonal Ge nanostructures have been conducted on Si substrates through deposition of
Ge with colloidal particles as a mask. The deposited Ge thin film possesses, according to the X-ray diffraction measurements,
in plane texture, being epitaxial and aligned with the (111) Si substrate. The size distribution of the patterned Ge nanostructures
is narrow, as indicated by the atomic force microscopy and scanning electron microscopy measurements. We have obtained Ge
nanostructures with lateral dimension of 490 nm (height 12 nm), 200 nm (height 6 nm) and 82 nm (height 6 nm) by using different
sizes of polystyrene spheres. We have performed in depth studies of the Ge nanostructures’ behavior due to thermal and rapid
thermal post-annealing processes. FT micro-Raman spectroscopy shows that there is no Si intermixing during the annealing process.
In order to quantify the changes in the height and lateral dimension, we have performed atomic force microscopy and white
light interferometry analysis. The changes in shape and the decrease in the area of a cross-section of Ge nanostructure will
be discussed in respect to similar results shown in the literature for Ge thin films during the annealing process. 相似文献
93.
Willers T Cezar JC Brookes NB Hu Z Strigari F Körner P Hollmann N Schmitz D Bianchi A Fisk Z Tanaka A Tjeng LH Severing A 《Physical review letters》2011,107(23):236402
We have been able to induce a linear dichroic signal in the Yb M(5) x-ray absorption white line of cubic YbInNi(4) by the application of a magnetic field. The nonzero integrated intensity of the magnetic field induced dichroic spectrum indicates a net noncubic 4f orbital polarization. A quantitative analysis of the temperature and field strength dependence establishes that the crystal-field ground state is a Γ(8) quartet. The results demonstrate the potential of magnetic field induced linear dichroism as a new powerful approach for the investigation of the degeneracy and orbital degrees of freedom of cubic heavy-fermion and Kondo systems. 相似文献
94.
Received June 24, 1997 相似文献
95.
96.
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98.
G. Beier J. Friese W. Henning P. Kienle H. J. Körner W. Wagner W. A. Mayer W. Mayer 《Zeitschrift für Physik A Hadrons and Nuclei》1990,336(2):217-222
Strongly damped collisions were studied in uranium induced reactions on110Pd and124Sn target nuclei near the barrier. The excitation-energy splitting was deduced from binary reaction yields and those in which the heavy fragment undergoes sequential fission. For systems with 87≦Z≦95 for the heavy fragment, the excitation energy is concentrated in the lighter nucleus, at best shared equally. The results indicate a non-equilibrated energy dissipation, and support nucleon exchange based on average single-particle strength functions as the underlying dissipation mechanism at the barrier. 相似文献
99.
100.
David N. Nikogosyan Helmut Grner 《Journal of photochemistry and photobiology. B, Biology》1995,30(2-3):189-193
An investigation of the photochemical properties of glycine, aspartic acid, valine, leucine and methionine was carried out using nanosecond 193 nm laser irradiation and high performance liquid chromatography analysis. The quantum yields of formation of hydrated electrons (Φe−) and decomposition of the substrate (Φd) were determined for the five aliphatic amino acids in neutral aqueous solution at room temperature. From the dependences of Φe− on the laser intensity it follows that the mechanism of photo-ionization is monophotonic (single step). The Φd values under Ar and in the presence of oxygen or N2O are interpreted on the basis of photo-ionization as the dominant process for decomposition of methionine and a significant contribution from photo-ionization in the other cases. A comparison was made between the Φd values (in the presence of oxygen) using irradiation at 193 nm and those from previous measurements at 213 nm. 相似文献