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  • 1
    Digitale Medien
    Digitale Medien
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 5 (1993), S. 2714-2718 
    ISSN: 1089-7666
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: A new experiment on plasma wake-field acceleration has been designed at the Budker Institute of Nuclear Physics in Novosibirsk. An intense modulated driving beam from the electron–positron booster (BEP), a storage ring, will be used to excite a nonlinear plasma wave in a dense plasma (n=1015 cm−3). Important advantages of this beam are its very low emittance (10−8 cm⋅rad in the vertical direction), high energy (850 MeV), and high intensity (1012 particles). A new technique for modulating this beam at a submillimeter wavelength is proposed. A simple numerical code has been developed to simulate the plasma wave excitation with plasma nonlinearity and with three-dimensional effects taken into account. The code allows the calculation of the radial structure of the nonlinear wake field including the focusing force which was mostly neglected in previous studies but which is especially important for experiment. The present numerical simulations show that, in the proposed experiment, a 1 GeV/m accelerating gradient over a macroscopic distance is attainable.
    Materialart: Digitale Medien
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  • 2
    Digitale Medien
    Digitale Medien
    Amsterdam : Elsevier
    Physics Letters A 180 (1993), S. 119-123 
    ISSN: 0375-9601
    Quelle: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Thema: Physik
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    ISSN: 1432-2242
    Schlagwort(e): Wheat relations ; Gliadin alleles ; Durum ; Carthlicum ; T. aestivum
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Polymorphism and inheritance of wheat storage protein, gliadin, of durum (macaroni) and carthlicum wheats have been studied. Analysis of gliadin in 78 cultivars and in F2 seeds of intercultivar crosses of durum wheat revealed three different chromosome 1A-encoded blocks of components similar to those found in common wheat (GLD1A2, GLD1A18, GLD1A19). Most of the durum cultivars studied had these three blocks; GLD1A2 was also frequent in common wheat. In contrast, all chromosome 1B-encoded blocks of durum clearly differed in component composition from those found in common wheat. Therefore, durum could not be an ancestor or a derivate of recent bread wheat. Analysis of gliadin in the collection of carthlicum wheat (14 accessions) revealed several suspected chromosome 1A, 1B, and 6A-controlled blocks, some of which were similar to those in common wheat, while others were different. Therefore, carthlicum is likely to be an ancestor or a derivate of some forms of bread wheat. There were also chromosome 1A and 6A-, but not 1B-encoded blocks which were identical in durum and carthlicum wheats. The results confirm that all three wheats share the same genome A, but emphasize the heterogeneity of genotypes among donors of this genome. Discovery of identical blocks in tetraploids and hexaploids indicates polyphyletic [from different genotypes of donor (s)] origin of these wheats.
    Materialart: Digitale Medien
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  • 4
    Digitale Medien
    Digitale Medien
    Copenhagen : International Union of Crystallography (IUCr)
    Acta crystallographica 54 (1998), S. 1216-1229 
    ISSN: 1399-0047
    Quelle: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Thema: Chemie und Pharmazie , Geologie und Paläontologie , Physik
    Notizen: Polarized Raman spectra have been obtained for tetragonal lysozyme single crystals of different relative quality. The Raman band at 507 cm−1, which corresponds to the totally symmetric stretch vibration of the gauche-gauche-gauche (ggg) disulfide bridges of the protein, has been shown to possess different polarization characteristics compared with the gauche-gauche-trans (ggt) disulfide bridge band at 528 cm−1. The relative intensities of the ggg and ggt bands in the polarized Raman spectra have been numerically estimated for a number of tetragonal lysozyme single crystals, the X-ray diffraction data of which are available from the Protein Data Bank. On the basis of comparison between the experimental and calculated polarization characteristics of the disulfide Raman lines, the following main conclusions have been drawn. The orientation of the protein molecules correlates with the average orientation of their ggg disulfide bridges. This in turn can be described by the ρggg value which reflects the average orientation of the S—S bonds with respect to the Z crystallographic axis and can be determined from polarized Raman spectra. Crystals of better quality are characterized by a better alignment of the protein molecules with respect to the Z axis, a smaller perturbation of the protein molecules in the crystal lattice and a somewhat higher interlattice water content.
    Materialart: Digitale Medien
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  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Applied microbiology and biotechnology 3 (1976), S. 1-7 
    ISSN: 1432-0614
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Summary The present study examines the processes of ballistic disintegration carried out to release active biopolymers. The relationship between the activity of unit volume of homogenates and the time of disintegration has been obtained. Correctness of this relationship for any process of disintegration can serve as the criterion of optimal chemical composition of the medium in which this process occurs. Only two quantitative criteria have been found sufficient for comparison of any regimes of ballistic disintegration. The theoretical conclusions are proved by experiments in ballistic disintegrators of two types.Torulopsis candida cells were used to release the succinate oxidizing enzyme.
    Materialart: Digitale Medien
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  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Physics of atomic nuclei 63 (2000), S. 1969-1972 
    ISSN: 1063-7788
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract We present some remarks on the $$\bar n$$ p partial branching ratios in flight at low momenta of antineutrons measured by the OBELIX Collaboration. A comparison is made to the known branching ratios from the p $$\bar p$$ -atomic states. The branching ratio for the reaction $$\bar n$$ p → π+π0 is found to be suppressed in comparison to what follows from the p $$\bar p$$ data. It is also shown that there is no so-called dynamical I=0 amplitude suppression for the process N $$\bar N$$ → K $$\bar K$$ .
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Physics of atomic nuclei 63 (2000), S. 801-811 
    ISSN: 1063-7788
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract The one-loop expression for the absorptive correction to the πd scattering length is discussed. Relevant Feynman diagrams are calculated both in the relativistic and in the nonrelativistic formalism. A simple expression is obtained for the one-loop correction that arises in the πd scattering length owing to the Fermi motion of the nucleons in the deuteron. This correction includes absorption effects. Fulfillment of the unitarity relation is verified explicitly.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    JETP letters 72 (2000), S. 410-414 
    ISSN: 1090-6487
    Schlagwort(e): 13.60.Le ; 13.75.Cs ; 14.40.Cs
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract It is shown that, if isospin is not conserved in a 0 0 -and f 0-meson mixing, forward-backward asymmetry arises in the pn→da 0 0 reaction. This effect increases near the reaction threshold. The asymmetry is estimated within the framework of a model in which the a 0 0 -f 0 mixing is due to the virtual π0↔η transition and the difference in masses of the charged and neutral kaons in decay channels. The angular asymmetry near the threshold of the pn→da 0 0 reaction was found to be large, of the order of 8–15%.
    Materialart: Digitale Medien
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  • 9
    Digitale Medien
    Digitale Medien
    Springer
    JETP letters 63 (1996), S. 235-240 
    ISSN: 1090-6487
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract The shape of the mass spectrum of the pp system produced near the threshold of the reaction pn→pp π − at initial proton momentum p lab≃2 GeV/s is discussed. It is shown that the shape of the spectrum becomes universal when the diproton system is produced with a large momentum transfer. All effects of the Coulomb and strong interactions in the final state are taken into account exactly for the model “Coulomb+separable Yamaguchi potential.” The solution presented for the amplitude of the reaction gives a good description of the experimentally observed shape of the spectrum near the peak (χ 2/d.f. =0.654).
    Materialart: Digitale Medien
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  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Journal of experimental and theoretical physics 86 (1998), S. 305-311 
    ISSN: 1090-6509
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract The states of a hydrogen atom with principal quantum numbers n⩽3 in a constant uniform magnetic field ℋ are studied. Coefficients in the expansion of the energy of these states in powers of ℋ2 up to the 75th order are obtained. Series for the energies of the states and the wave functions are summed to values of ℋ on the order of the atomic magnetic field. A generalization of the moment method upon which these calculations are based can be used in other cases in which a hydrogen atom is perturbed by a potential with a polynomial dependence on the coordinates.
    Materialart: Digitale Medien
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