hole density holes/ absolute temperature K Prandtl number 严Tt momentum relaxation Bloch wave function time electronic charge 1.6×10-19C volumetric flow rate m/s q heat flow vVvvvwZ electron velocity base resisto direct base-emitter BRRR eynolds number generator internal direct voltage supply mv total resistance Zener voltage Stefan-Boltzmann 5.67×10 characteristic impedance Q2 W/m2 K© 2000 by CRC Press LLC Symbol Quantity Unit p hole density holes/cm3 Pr Prandtl number ybk Bloch wave function q electronic charge 1.6 ¥ 10–19 C q heat flow W RB base resistor Re Reynolds number Rg generator internal W resistance RG total resistance W s conductivity S s Stefan-Boltzmann 5.67 ¥ 10–8 constant W/m2 K4 Symbol Quantity Unit T absolute temperature K t momentum relaxation s time q volumetric flow rate m3 /s v electron velocity m/s VBE direct base-emitter V voltage VCC direct voltage supply V VT thermal voltage mV VZ Zener voltage V W power W Zo characteristic impedance W