例句與造句

1. Therefore, the bracket on " A " is just the Lie bracket of tangent vector fields and the anchor map is just the identity.
2. Denote the tangent vector field of an observer's worldline ( in a " timelike " congruence ) as Z ^ a, and then one could construct induced " spatial metrics " that
3. As an extension of this idea in generic curved spacetimes, \ { l ^ a \,, n ^ a \ } can still be aligned with the tangent vector field of null radial congruence.
4. If, now, E _ 1, E _ 2, \ ldots, E _ m is a local orthonormal frame ( of tangent vector fields ) on the same open subset of " M ", then we can define the mean curvatures of the immersion by
5. A Poisson manifold ( " M ", ? ) gives naturally rise to a Lie bialgebroid on " TM " ( with the commutator bracket of tangent vector fields ) and " T * M " with the Lie bracket induced by the Poisson structure.
6. It's difficult to find tangent vector field in a sentence. 用tangent vector field造句挺難的
7. Similarly, the hairy ball theorem of algebraic topology says that " one cannot comb the hair flat on a hairy ball without creating a cowlick . " This fact is immediately convincing to most people, even though they might not recognize the more formal statement of the theorem, that there is no nonvanishing continuous tangent vector field on the sphere.