In thermodynamics, the symbol $Q$ is usually used to represent the total heat transfer associated with a non-infinitesimal process. Considering this, and standard notation for transport equations in thermodynamics... The term $\delta Q$ represents: The rate of heat transfer, in units of energy per time
The total heat transfer over some infinitesimal process, in units of energy
The total heat transfer over some non-infinitesimal process, in units of energy
This combination of symbols has no meaning, in thermodynamics notation The term $\text{d} Q$ represents: The rate of heat transfer, in units of energy per time
The total heat transfer over some infinitesimal process, in units of energy
The total heat transfer over some non-infinitesimal process, in units of energy
This combination of symbols has no meaning, in thermodynamics notation The term $\dot{Q}$ represents: The rate of heat transfer, in units of energy per time
The total heat transfer over some infinitesimal process, in units of energy
The total heat transfer over some non-infinitesimal process, in units of energy
This combination of symbols has no meaning, in thermodynamics notation The term $\frac{\text{d}}{\text{d}t}Q$ represents: The rate of heat transfer, in units of energy per time
The total heat transfer over some infinitesimal process, in units of energy
The total heat transfer over some non-infinitesimal process, in units of energy
This combination of symbols has no meaning, in thermodynamics notation The term $\Delta Q$ represents: The rate of heat transfer, in units of energy per time
The total heat transfer over some infinitesimal process, in units of energy
The total heat transfer over some non-infinitesimal process, in units of energy
This combination of symbols has no meaning, in thermodynamics notation