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21.
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Erythrocyte ghosts were exposed to various levels of oxyradical shock in order to identify the extent of accumulation of peroxidative intermediates. Malondialdehyde reacting end products were the same in all different models. But, the accumulation of dienyl radical species increased with higher intensity of oxyradical shock. These dienyl radicals may rearrange to create a homogeneous smectic multilamellar microenvironment which may be more fluid in terms of the molecular dynamics. 相似文献
23.
The effect of transverse stitching on the stresses in the adhesive is investigated using an adhesive sandwich model with nonlinear adhesive properties and a transverse stitching model for adhesive bonded composite single-lap and double-lap joints. Numerical results indicate that, among all stitching parameters, thread pretension and stitch density have significant effect on the peel stresses in the adhesive; increase in the thread pretension and the stitch density leads to a decrease in peel stress in the adhesive, while an increase in other parameters generally results in a negligible reduction in peel stress. The effect of stitching was found to be negligible on the shear stresses in the adhesive. Thus it is concluded that stitching is effective for the joints where peel stresses are critical and ineffective for those where shear stresses are critical. 相似文献
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Flynn P.J. Jain A.K. 《IEEE transactions on pattern analysis and machine intelligence》1991,13(10):1066-1075
BONSAI, a model-based 3D object recognition system, is described. It identifies and localizes 3D objects in range images of one or more parts that have been designed on a computer-aided-design (CAD) system. Recognition is performed via constrained search of the interpretation tree, using unary and binary constraints (derived automatically from the CAD models) to prune the search space. Attention is focused on the recognition procedure, but the model-building, image acquisition, and segmentation procedures are also outlined. Experiments with over 200 images demonstrate that the constrained search approach to 3D object recognition has an accuracy comparable to that of previous systems 相似文献
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28.
Xinjian Duan Mukesh Jain David S. Wilkinson 《Metallurgical and Materials Transactions A》2006,37(12):3489-3501
A heterogeneous finite element model with randomly distributed inhomogeneities has been developed for the determination of
the forming limit diagram (FLD) for thin aluminum sheet material based on the prediction of localized necking. The strength
difference between the inhomogeneities and the matrix is ascertained either from the fluctuation of the experimental stress-strain
curve or from a micromechanical analysis that uses a representative particle field. By changing the specimen geometry and
friction conditions, different stress states (or strain paths) are achieved. A plot of the critical Oyane fracture parameter
is used to identify the limit strain state. Also, a plot of equivalent plastic strain rate is used to distinguish the boundary
of intense shear bands and hence to identify where to take the measurement point. Both a plane stress model and a three-dimensional
(3-D) model are adopted to predict the shear banding phenomenon and hence the FLD. The predicted FLD agrees well with the
measurements from a recent round robin experimental FLD involving several independent research laboratories. The Taguchi method
is applied to assess how the various parameters involved in the heterogeneous model affect the calculated forming limit strain. 相似文献
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M. Jain 《Journal of Materials Science》1992,27(2):399-407
The evolution of dislocation structure during room-temperature, uniaxial, low-cycle fatigue of an overaged Al-Mg-Si alloy is studied. Ageing at 450°C produces a fine dispersion of Mg2Si precipitate particles. During fully reversed strain-controlled cyclic tests, these fine particles restrict deformation to local regions and a stable dislocation substructure is developed early in fatigue life. Substructural observations of hardening and saturation by transmission electron microscopy reveal extensive dislocation band formation on Mg2Si precipitate rods. Various microstructural features such as configuration of tangled dislocations, dislocation cells, precipitate morphologies, sizes, precipitate-free zones, etc., have been examined during cyclic hardening and saturation. The results have been analysed in terms of kinematic and isotropictype microstructural mechanisms. 相似文献