Two statements of the problem of arbitrary buckling forms (BFs) (including synphasic, antiphasic, mixed flexural, flexural-shear, and shear forms in the tangential directions) of general-form sandwich shells and two schemes of its solution by the FEM are given. The first of the schemes is based on the use of refined linear equations for determination of the precritical stress-strain state and linearized equations of neutral equilibrium with all parametric addends necessary to determine the critical loads and reveal the possible BFs. The second one uses the general geometrically nonlinear relations of elasticity theory for investigation of the whole deformation process up to buckling in terms of a modified incremental (stepwise) statement of the problem. Examples of solution of particular problems are given.Center for Study of Dynamics and Stability, Tupolev Kazan' State Technical University, Kazan', Tatarstan, Russia. Translated from Mekhanika Kompozitnykh Materialov, Vol. 36, No. 4, pp. 473–486, July–August, 2000. 相似文献
The shape coexistence in 188Pb is investigated in terms of the projected shell model. Analyzing the experimental data with the calculated results, it is shown that the three shapes, sphere, oblate and prolate, coexist with each other in the low-lying excited states. The prolate band exhibits a mixture between two kinds of multi-particle-hole configuration. The mixing is discussed and the mixing coefficients are given, meaning the νi13/2 pair alignment happens gradually in this case. The oblate (πh9/22p-2h) band structure is predicted and the 2+ prolate state is in the range of 804-880 keV. 相似文献
Summary: The synthesis of PEDOT nanoparticles and vesicles by dispersion polymerization in a methanol/water mixture (3/2, v/v) is reported, using either ammonium persulfate or iron(III) p‐toluenesulfonate as oxidants and α‐EDOT‐PEO as a reactive stabilizer. The influence of the oxidant as well as the α‐EDOT‐PEO molar mass and concentration on the core‐shell particle morphology and conductivity properties have been investigated. PEDOT particles with conductivities up to 1.5 × 10−2 S · cm−1 have been obtained in high yield.
TEM image of PEDOT vesicles prepared using PEO‐based stabilizers of 25 000 g · mol−1 in water/methanol mixture (2:3 v/v) at room temperature using ammonium persulfate as an oxidant. 相似文献
In this paper we study the existence and stability of two-dimensional discrete gap
breathers in a two-dimensional diatomic face-centered square lattice
consisting of alternating light and heavy atoms, with on-site
potential and coupling potential. This study is focused on
two-dimensional breathers with their frequency in the gap that
separates the acoustic and optical bands of the phonon spectrum. We
demonstrate the possibility of the existence of two-dimensional gap
breathers by using a numerical method. Six types of two-dimensional
gap breathers are obtained, i.e., symmetric, mirror-symmetric and
asymmetric, whether the center of the breather is on a light or a
heavy atom. The difference between one-dimensional discrete gap
breathers and two-dimensional discrete gap breathers is also
discussed. We use Aubry's theory to analyze the stability of
discrete gap breathers in the two-dimensional diatomic face-centered
square lattice. 相似文献
The exponential convergence rate in entroy is studied for symmetric forms, with a special attention to the Markov chain with
a state space having two points only. Some upper and lower bounds of the rate are obtained and five examples with precise
or qualitatively exact estimates are presented.
相似文献
Core‐shell microparticles with functional multilayer shell walls consisting layers of naphthalene‐labeled polyanion ANp10 and polyviologen (PV) were fabricated through layer‐by‐layer (LbL) self‐assembly. Fluorescence emission from the naphthyl group in the ANp10 layer was found to be quenched by the viologen group in the PV layer regardless in inner or outer layer. This quenching was attributed to electron transfer from the excited naphthyl donor to the viologen acceptor. The quenching efficiency was simply tuned by changing numbers of the ALG/CHI bilayer spacer and PV layer. The resulting core‐shell microparticles will be served as a novel light‐harvesting antenna system.