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Conclusions The principle of optimal deformations establishes relations which must apply between alterations in bond lengths and valence angles in planar cyclic molecules; they can be used to describe the changes in three-membered ring geometry resulting from the introduction of substituents, or the inclusion of a cyclopropane ring, in polycyclic systems.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 45–49, January, 1982. 相似文献
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B.L. Ioffe 《Nuclear Physics B》1981,188(2):317-341
The polarization operator of quark currents with baryon quantum numbers is considered in quantum chromodynamics. The non-zero mean vacuum values of the field operator products are taken into account. The sum rules are obtained assuming that in the virtuality region ~1 GeV, among the mean vacuum values violating the chiral invariance, the most important is . Saturating these sum rules by the lowest baryonic states one is able to calculate the masses of the isobar Δ and nucleon N, MΔ = 1.4 GeV, MN = 1 GeV, up to 15% through the known value . The mass splitting in the baryonic decuplet is calculated in first order in the current strange quark mass ms = 150 MeV. Certain results for other baryonic resonances have also been obtained. 相似文献
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Chih-Hao Lee Hsin-Ho Chang Hui-Chia Su Yu-Han Wu Chih-Wei Hu L.J. Chang A. Ioffe K. Bussmann Th. Brückel 《Physica B: Condensed Matter》2009,404(17):2565-2567
The magnetic correlation length of a mixed nickel ferrite powder was studied by a newly commissioned depolarized neutron beamline at the W3 port of Tsing Hua Open Pool Reactor (THOR). In this work, Ni ferrite powder samples with different packing densities were studied. The magnetic correlation lengths of the sample were observed to be 2 μm at virgin state and about 3.1 μm at remanent state from the packing density of 20–60%. This magnetic domain size is smaller than particle size. No significant change of domain size at this packing density implies the domain wall motion is hindered by the porosity effectively up to at least 60% of packing density. 相似文献
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