emission

• 指发出、排出或释放某物的行为或过程，常指光、热、气体、粒子等的散发；也指排放出来的物质本身。

A noun referring to the act of sending out or releasing something, such as light, heat, gas, or particles.

1. Release of substancesB2formalscientific

   The act of releasing or discharging something, especially gas, radiation, or particles.

   排放

   • The factory reduced its carbon emissions by 30%.
   • Scientists measure the emission of greenhouse gases from vehicles.
   • The emission of radioactive particles was detected by the sensors.

   同义词dischargeeffluxejectionemanationexhalationoutflowrelease

   反义词absorptioncontainmentretention

2. Production of energyB2formaltechnical

   The production and sending out of light, heat, sound, or other forms of energy.

   发射

   • The laser's emission of light is extremely focused.
   • The sun's emission of heat sustains life on Earth.
   • The device controls the emission of radio waves.

   同义词dischargeemanationoutputradiationtransmission

   反义词absorption

3. Vehicle exhaustB1formaltechnical

   The waste gases produced by an engine, especially in a car.

   尾气

   • The car's emission levels are tested annually.
   • Stricter laws limit vehicle emissions in urban areas.
   • Diesel engines produce higher emissions than petrol ones.

   同义词dischargeexhaust