集极环

So before applying Mather's theorem of connecting orbits to concrete Hamiltonian system, we have to check whether the set W〓 is empty or not, and which cohomology classes are C-equivalent. In present paper, by investigating the topological structure of action minimizing sets near a co-dimensional one torus which is preserved under generic perturbations and becomes hyperbolic in nearly integrable Hamiltonian system.

与传统的Poincaré-Melnikov方法相比，我们方法明显优越之处在于，一方面我们的方法不仅可以得到双曲环面之间的异宿轨道，而且当该环面附近的其它环面破裂时，可以得到不同Mather集之间的连接轨道，另一方面，我们把异宿轨的存在性的证明转化为双曲环面极小同宿轨的某种弱孤立性的证明，所需条件比Poincaré-Melnikov方法弱得多。

Then can weld starting the resistance directly on the rotor winding, and cancel collecting the electric ring and electric brush.

将定子一种极数的磁场感应于转子绕组中的电流，通过集电环和电刷，但由另一种极数的磁场感应的电流，却自动流经另一闭合回路，而不通过集电环和电刷：于是，如果后一种极数是电动机的工作基波磁场，而把前一种极数作为用以起动的谐波磁场，则可以把起动电阻直接焊接在转子绕组上，而把集电环和电刷取消，从而出现了转子电路上无集电环、无电刷、无触点的谐波起动绕线型感应电动机。

By the time of its fall, most of the prisoners were writers who had written against the corruptions of the government.

到它被攻陷的时候，里面多数的犯人是写了反对政府贪污文章的作家。

The most obvious variation to ovum morphological character was that the color was changed from light green to sepiaceous in embryonic development, and all the ovums were almost hatched after 96h.

在胚胎发育过程中卵的形态特征最明显的变化是颜色从淡绿到深褐色，卵在发育96h后卵基本全部孵化。