【单选题】高速珠磨法的原理?
A.
在超声波作用下,液体发生空化作 (cavitaton) ,空穴的形成、增大和闭合产生极大的冲击波和剪切力,使细胞破碎。
B.
细胞和极细的研磨剂在搅拌桨作用下充分混合,珠子之间及珠子与细胞之间互相剪切、碰撞,促使细胞壁破裂,释放内含物。
C.
细胞悬浮液在高压作用下从阀座与阀之间的环隙高速 ( 可达到 450m / s) 喷出后撞击到碰撞环上,经过碰撞环的撞击后改变方向从出口管喷出,使细胞经历较高的流速下的剪切碰撞发生较大的变形,从而达到破碎细胞的目的。
【判断题】The first level of a company structure chart is the top management for the organization. The shareholders’ meeting is at the top of the structure chart, it is the authority of the company.
【简答题】The First Day at My Senior High School Today is September1,2012.It is the first day of my senior high school.Everything in the school is new to me. The school is very modern. The gate of the school is...
【简答题】一条公路长100千米、宽8米,这条高速公路占地( )平方米,合( )公顷。
【判断题】The first level of a company structure chart is the top management for the organization. The shareholders' meeting is at the top of the structure chart, it is the authority of the company.
【判断题】如果通过某一截面积磁通为零,则该截面积的磁感应强度一定为零。