We calculated the mechanical properties, electronic structure, theoretical hardness and optical properties of V4AlC3 using the first-principles method. The results show that V4AlC3 shows a better performance of the resistance to shape change and against uniaxial tensions and has a slight anisotropy on elasticity. Moreover, it is more brittle than α-Nb4AlC3 and Ta4AlC3. The chemical bonding of V4AlC3 is a combination of covalent, ionic and metallic nature. The calculated theoretical hardness is 9.33 GPa, and the weaker covalent bonding of Al–V is responsible for the low hardness of V4AlC3. The optical properties (dielectric function, absorption spectrum, conductivity, energy-loss spectrum and reflectivity) are discussed in detail. It is shown that V4AlC3 has the potential to be used as a promising dielectric material and coating to avoid solar heating.

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Fabric anisotropy has a significant influence on the mechanical behavior of sand. An anisotropic plasticity model incorporating fabric evolution is formulated in this study. Information on the overall stress–strain relationship and micromechanical fabric states from DEM numerical tests is used in the development of the constitutive model, overcoming the difficulties of fabric measurement in physical tests. The framework of the model and its formulations for fabric evolution, plasticity, and dilatancy enables it to capture the strength, shear modulus, and dilatancy of sand under both monotonic and cyclic loading. The model is validated against DEM numerical tests and physical laboratory tests on samples with different initial fabric, showing good agreement between the simulation and test results for the anisotropic stress–strain behavior of sand. The use of DEM test data also allows for the validation of the model on the micromechanical fabric level, showing that the model can reproduce the fabric evolution and its influence on key constitutive features reasonably well. The model is further applied to analyze the liquefaction behavior of sand, exhibiting the significant influence of fabric anisotropy on both liquefaction resistance and postliquefaction shear deformation.

We present a novel approach for improving the shape statistics of medical image objects by generating correspondence of skeletal points. Each object’s interior is modeled by an s-rep, i.e., by a sampled, folded, 2-sided skeletal sheet with spoke vectors proceeding from the skeletal sheet to the boundary. The skeleton is divided into three parts: the up side, the down side and the fold curve. The spokes on each part are treated separately and, using spoke interpolation, are shifted along that skeleton in each training sample so as to tighten the probability distribution on those spokes’ geometric properties while sampling the object interior regularly. As with the surface/boundary-based correspondence method of Cates et al., entropy is used to measure both the probability distribution tightness and sampling regularity, here of the spokes’ geometric properties. Evaluation on synthetic and real world lateral ventricle and hippocampus datasets demonstrate improvement in the performance of statistics using the resulting probability distributions. This improvement is greater than that achieved by an entropy-based correspondence method on the boundary points.

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