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991.
R. Sankarasubramanian C. S. Jog T. A. Abinandanan 《Metallurgical and Materials Transactions A》2002,33(4):1083-1090
We examine the symmetry-breaking transitions in equilibrium shapes of coherent precipitates in two-dimensional (2-D) systems
under a plane-strain condition with the principal misfit strain components ε*
xx
and ε*
yy
. For systems with cubic elastic moduli, we first show all the shape transitions associated with different values of t=ε*
yy
/ε*
xx
. We also characterize each of these transitions, by studying its dependence on elastic anisotropy and inhomogeneity. For
systems with dilatational misfit (t=1) and those with pure shear misfit (t=−1), the transition is from an equiaxed shape to an elongated shape, resulting in a break in rotational symmetry. For systems
with nondilatational misfit (−1<t<1; t ≠ 0), the transition involves a break in mirror symmetries normal to the x- and y-axes. The transition is continuous in all cases, except when 0<t<1. For systems which allow an invariant line (−1≤t<0), the critical size increases with an increase in the particle stiffness. However, for systems which do not allow an invariant
line (0<t≤1), the critical size first decreases, reaches a minimum, and then starts increasing with increasing particle stiffness;
moreover, the transition is also forbidden when the particle stiffness is greater than a critical value. 相似文献
992.
Small-signal and temperature noise model for MOSFETs 总被引:1,自引:0,他引:1
993.
994.
The results of finite element calculations for a hollow sphere micromodel are used to examine the underlying assumptions and the specific yield functions in the dilatant plasticity theories of Gurson (1977) and Mear and Hutchinson 相似文献
995.
996.
Phase transformations in particles of ultrafine powders of graphite, hexagonal boron nitride, and quartz during rapid heating and cooling by passage through a laser beam were investigated. A continuous infrared laser with a wavelength of 10.6 μm was used as a heat source through which the powders were recycled several times. Methods of concentrating the product phases are described. Particles of diamond, carbides, cubic boron nitride, koesite and stishovite were obtained in the mixed products. 相似文献
997.
A new method is described for transferring phase contrast in electron microscopy without artefacts due to oscillations of the phase contrast transfer function (PCTF). This is carried out by in situ image synthesis of two or three exposures transferred with complementary PCTF. The essence of the technique is to use optimized transfer attenuation functions to cut off the negative parts of PCTF. 相似文献
998.
999.
Translated from Atomnaya Énergiya, Vol. 67, No. 2, pp. 97–100, August, 1989. 相似文献
1000.