Physics is a basic subject, and other advanced physical science research topics are supported by physics. B acting on a system and measuring AB physical quantity are not the same concept. The former will not lead to the collapse of the country. Finally, being acted on by A is different from measuring A. When measuring the physical quantity of A, the value that can be obtained can only be a certain eigenvalue of A..
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In theoretical physics, if the operator a' of a physical quantity acts on a state function $,it is equal to a constant a times $,that is, A'$=a$. So for the state of this microscopic system described by $,physical quantity A has a definite value A, which is called the eigenvalue of physical quantity operator A', and $ is called the eigenstate or eigenfunction or eigenfunction of A'.
In materials science, a polymer is intrinsic if it is not doped with any substance. For example, conductive polymer materials include intrinsic conductive polymer (undoped conductive polymer) and doped conductive polymer, and the conductivity of doped conductive polymer is greatly improved.