六角形的

In part two, the optical spatiotemporal pattern in ring optic cavity is investigated. Using delay feedback with spatial perturbation method, the system shows roll, square, hexagon, homocentric circle,"honeycomb"and"snowflower" pattern with different spatial perturbation functions. Different patterns can be coexist and compete each other with the same perturbation function, which is the new character of this optical system with delay feedback.

第二部分，利用延时反馈的空间微扰方法研究了环形腔中二能级介质的光学时空斑图的控制，在不同的微扰函数作用下，出现了滚筒状、四方形、六角形、蜂窝状、同心圆以及&雪花&状等不同的斑图，并且在相同的微扰函数下出现了不同斑图之间的竞争，这种竞争是我们发现的这一具有空间微扰的延时反馈非线性光学系统光学斑图的新特征。

When used fir fastening,all screws are provided with means for applying a torqueto them;this may consist of a square of hexagonal head for a wrench,a head with a slot or a cross-shaped recess for a screwdriver,a cylindrical head with a recess fitting a special wrench,or a slot or recess on one end fitting a screwdriver or special wrench and no head.

当二手的枞树系结物，所有的螺丝钉用应用一个转力矩到他们的方法来提供；这可能为一个扳钳有一个六角形头的正方形，一个头用一个位置或者一个跨为一个螺丝起子作形了休息，一个圆筒形的头用一个休息适宜的一个特别的扳钳、或在一端上的一个位置或休息适宜的一个螺丝起子或特别的扳钳和没有头。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。