Twelve P-chiral phosphine oxides were screened for their ability to act as a chiral Lewis base catalyst for the asymmetric hydrosilylation of ketimines, providing chiral amines in good conversion and yield, but relatively poor enantioselectivity (ee <30%). Mechanistic studies paralleling work on chiral sulfinamides have shown a non-linear relationship of catalyst enantioselectivity and the chir...

Through computer enumeration with the aid of topological results, we catalogue all 18 closed nonorientable P-irreducible 3-manifolds that can be formed from at most eight tetrahedra. In addition we give an overview as to how the 100 resulting minimal triangulations are constructed. Observations and conjectures are drawn from the census data, and future potential for the nonorientable census is ...

As is known, tetrahedron equations lead to the commuting family of transfer-matrices and provide the integrability of corresponding three-dimensional lattice models. We present the modified version of these equations which give the commuting family of more complicated two-layer transfer-matrices. In the static limit we have succeeded in constructing the solution of these equations in terms of e...

Locomotion and manipulation optimization is essential for the performance of tetrahedron‐based mobile mecha‐ nism. Most of current optimization methods are constrained to the continuous actuated system with limited degree of freedom (DOF), which is infeasible to the optimization of binary control multi‐DOF system. A novel optimization method using for the locomotion and manipulation of an 18 DO...

Computational fluid dynamics simulations result in large multivariate data sets with information such as pressure, temperature and velocity available at grid points for a sequence of steps. Velocity data is typically visualized by displaying a particle animation or streamlines. We present an efficient method for calculating particle paths based on velocity data from curvilinear grids. In order ...

Crystals of tricalcium silicate having a monoclinic superstructure transformed into a rhombohedral structure when they were heated at 1200 °C with gas flame: a=7.135(6) A, c=25.586(15) A, space group R3m, and contents of 9 x Ca2,9sSio,9sAlo,o40s. The rhombohedral structure has been determined based on a set of 371 diffraction intensities measured with a single-crystal diffractometer giving a fi...

We give a rigorous geometric proof of the Murakami-Yano formula for the volume of a hyperbolic tetrahedron. In doing so, we are led to consider generalized hyperbolic tetrahedra, which are allowed to be non-convex, and have vertices ‘beyond infinity’; and we uncover a group, which we call 22.5K, of 23040 = 30 · 12 · 2 scissors-class-preserving symmetries of the space of (suitably decorated) gen...

|We are often required to generate a Delaunay mesh whose element size is within a constant factor of a control spacing function, i.e., well-conformed, in addition to the fact that each mesh element has small aspect ratio, i.e., well-shaped. However, generating wellshaped Delaunay meshes is an open problem for a long time. Observe that slivers have small radius-edge ratio thus the Delaunay trian...