Calculation of moderator analogues for 14 MeV neutrons as source were made at a IBM/PC AT computer using TAMAKER-ANISN program and 46 groups (25 neutron groups, 21 photon groups) UW cross section data. The intensifyin...Calculation of moderator analogues for 14 MeV neutrons as source were made at a IBM/PC AT computer using TAMAKER-ANISN program and 46 groups (25 neutron groups, 21 photon groups) UW cross section data. The intensifying effect of lead and natural uranium for moderating 14 MeV neutrons is confirmed. Adopting proper structure of the moderator, the intensifying factor M (times) may be larger than 3. Using lead and natural uranium in sub-critical assemblies (or call boosters),with 14 MeV neutrons as source, with the same dimension as that of above, the intensifying effect is also condrmed. With a proper structure of sub-critical assembly,the intensifying factor M may be close to or eved larger than (1 - k)-1 where k isthe effective multiplication factor.展开更多
This paper presents the stress and strain distrihution obtained numerically in thethickness direction in the central region of symmetric composite laminates underuniaxial exlension and in-plane pure shear loading. It ...This paper presents the stress and strain distrihution obtained numerically in thethickness direction in the central region of symmetric composite laminates underuniaxial exlension and in-plane pure shear loading. It is shown that in the symmetricangle-ply laminates,near the interlaminar surface,thereis an interlaminarboundary-layer effect.The abrupt change of the fiber orientation at the interlaminarsurface causes a high concentration of stresses and a local three dimensional stress state.展开更多
文摘Calculation of moderator analogues for 14 MeV neutrons as source were made at a IBM/PC AT computer using TAMAKER-ANISN program and 46 groups (25 neutron groups, 21 photon groups) UW cross section data. The intensifying effect of lead and natural uranium for moderating 14 MeV neutrons is confirmed. Adopting proper structure of the moderator, the intensifying factor M (times) may be larger than 3. Using lead and natural uranium in sub-critical assemblies (or call boosters),with 14 MeV neutrons as source, with the same dimension as that of above, the intensifying effect is also condrmed. With a proper structure of sub-critical assembly,the intensifying factor M may be close to or eved larger than (1 - k)-1 where k isthe effective multiplication factor.
文摘This paper presents the stress and strain distrihution obtained numerically in thethickness direction in the central region of symmetric composite laminates underuniaxial exlension and in-plane pure shear loading. It is shown that in the symmetricangle-ply laminates,near the interlaminar surface,thereis an interlaminarboundary-layer effect.The abrupt change of the fiber orientation at the interlaminarsurface causes a high concentration of stresses and a local three dimensional stress state.
