partial differentiation
偏微分法，偏导法

• virtual base
• virtual displacement
• virtual focus
• virtual height
• virtual image
• virtual object
• virtual pitch
• virtual space
• virtual valence band
• opsearch
• optacon
• optar
• opthalmic instrument
• opthalmic optics
• opthalmic plastic
• Opththalmic contact lens radius measuring device
• optiaclly-matched crystals
• optiamal linearization
• optiaml characteristics
• optic
• optica accessories
• optica arrangement
• optica briidge circuti
• optica generation
• optical