Greek letters1, Α α alpha a:lf Alpha angle; coefficient Α α: Alpha Alpha Yueqing People’s Hospital Ultrasound Department Xu Qing2, Β β beta bet Beta flux coefficient; angle; coefficient Β β: Beta Beta3, Γ γ gamma ga:m Gamma conductivity coefficient (lowercase) Γ γ: Gamma Gamma4, Δ δ delta delt Delta variation; density; refractive index Δ δ: delta delte5, Ε ε epsilon ep`silon base of log Ε ε: epsilon Epsilon6, Ζ ζ zeta zat truncation tower coefficient; azimuth; impedance; relative viscosity; atomic number ζ: Jetta Zeta7, Η η eta eit Eta hysteresis coefficient; efficiency (lowercase) η: eta Eta8 . Θ θ thet θit Theta temperature; phase angle Θ θ : Theta Theta9 . Ι ι iot aiot Jota tiny, a little Ι ι : Iota Iota10 . Κ κ kappa kap kappa dielectric constant Κ κ : kappa Kappa11 . ∧ λ lambda lambd wavelength (lowercase); volume Λ λ : lambda Lambda12 , Μ μ mu mju mu magnetic permeability; micro (thousandths); amplification factor (lowercase) Μ μ: mu Mu13 , Ν ν nu nju Nu magnetoresistive system Ν ν: ar Nu14 , Ξ ξ xi ksi Ξ ξ: ksi Xi15 , Ο ο omicron omik`ron Omicron Ο ο: omicron Omicron16 , pi π pi pai pai circumference = circumference ÷ diameter = 3.1416 Π π: pai Pi17 , Ρ ρ rho rou meat resistance coefficient (lowercase) Ρ ρ: soft Rho18 , ∑ σ sigma `sigma sigma sum (uppercase), surface density; transductance (lowercase) Σ σ: sigma Sigma19 , Τ τ tau tau set time constant Τ τ: set Tau20 , Υ υ upsilon jup`silon Upsilon displacement Υ υ: Upsilon Upsilon21 , Φ φ phi fai Buddha Ai magnetic flux; angle Φ φ: fai Phi22 , Χ χ chi phai West Χ χ: ware Chi23 , Ψ ψ psi psai Psi angular velocity; dielectric flux (electrostatic force lines); angle Ψ ψ: Psi Psi24 , Ω ω omega o`miga omega ohm (uppercase); angular velocity (lowercase); angle Ω ω: omega Omega