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991.
Using light-front dynamics, and the notion of the running effective quark mass, we propose a model of the three-quark nucleon wave function, which accounts simultaneously both for the low and the high energy experimental data. Our wave function is a product of a spinor part, inferred from the QCD sum rules, and a gaussian scalar factor, taken for simplicity. Including all three Ioffe currents we get from one wave function both the negative neutron charge radius 〈r2neutron=-0.108 fm2 and the decreasing d/u ratio in the proton for xBj increasing from 0.5 to 1.  相似文献   
992.
A search for the decays γ→ρπ, γ→JX and γ→γa (whereX is undetermined and a is an axion) has been completed using the LENA detector at the DORIS storage ring. No evidence for any of these processes was found. For these decay modes we set branching fraction upper limits (90% C.L.) of 2.1×10?3, 2.0×10?2 and 9.1×10?4, respectively.  相似文献   
993.
Diffraction of X-rays or neutrons can not be used to obtain details about the atomic vibrational anisotropy in the case of amorphous materials due to the lack of well-defined Bragg reflections. Mössbauer spectroscopy can yield some information in such cases, either via the Goldanskii-Karyagin effect or by applying a magnetic field, preferably along the beam axis. The latter method can be applied to the (preferably diamagnetic) samples exhibiting an electric quadrupole interaction (preferably non-axial) and the magnetic field should be chosen in such a way as to produce significant off-diagonal elements in the hyperfine hamiltonian. The external magnetic field method is capable of yielding much more information than the Goldanskii-Karyagin effect in most cases, provided sufficiently strong magnetic fields are available. Some examples of the129I Mössbauer spectra have been calculated to show the usefulness and sensitivity of the external magnetic field method.  相似文献   
994.
The influence of silica addition and of the annealing on the structure and properties of phosphate coatings are investigated. It has been observed that silica stabilizes phosphates and reduces the transport of iron towards the surface.  相似文献   
995.
996.
An approach is proposed to use the isotope ratios93Zr/96Zr,91Zr/96Zr and101Ru/104Ru for the determination of plutonium contriubtion to the total burnup of a spent nuclear reactor fuel of low initial enrichment in235U (3.6%). This approach was verified by determining the total burnup of the fuel from the137Cs and148Nd monitors and subtracting the partial burnup due to235U from the value obtained.  相似文献   
997.
A new space-time model for hadron-nucleus collisions is proposed, where particles at the instant of creation are not only immature but their maturity rate is enhanced in the presence of other hadronic matter, as in a nucleus. With only one free parameter, the model can explain dnAp/dν, dnAπ/dν, RAp(EL), and the A-dependences of σinpA and σinπA.  相似文献   
998.
The assumption of asymptotic validity of early KNO scaling combined with the existence of diffraction is shown to result in strong restrictions on the asymptotic multiplicity distributions.  相似文献   
999.
The ESR spectra of a series of CuII Schiff base complexes have been investigated in liquid and frozen solutions. The structures of these complexes are estimated on the basis of superhyperfine interactions and molecular orbital coefficients α2 and β21 calculated from copper hyperfine parameters.  相似文献   
1000.
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