变色机理
mechanism of photochromism
Discoloration
防变色法兰绒
tarnish resistant flannel
复合防变色工艺
multiple anti-tarnish process
可逆温致变色防伪纸
Reversible Thermochromic Anti-counterfeiting Paper
病变机理
mechanism of pathological change
pathological changes mechanism
电流变机理
electrorheological mechanism