Here, however, you can have a sign reversal.

这里却可以有相反符号。

youdao

The sign reversal applies only to quantum numbers (properties) which are additive, such as charge, and not to mass, for example.

举例来说正负号只适用于附加量子数，例如电荷，而不是质量。

youdao

The sign reversal applies only to quantum numbers (properties) which are additive, such as charge, and not to mass, for example.

举例来说正负号只适用于附加量子数，例如电荷，而不是质量。

youdao