放热的英文：
egress of heat
giving up of heat
liberation of heat
heat release

参考例句：

They know nothing about exothermic chemical reactions.
他们封放热的化学反应一无所知。

In general, exothermic combustion reactions require two reactants
一般说来，放热燃烧反应需要两种反应物。

Some reactions produced with an evolution of heat: these are said to be exothermic
有些反映伴随热的释放:这些称之为放热发应。

The most important exothermal reactions in the crust can be expected from the chemical transformations of sulfides
地壳中能够料想到的最重要的放热化学反应是硫化物的化学转变。

The selectivity behavior becomes coupled with the heat release behavior for this particular reaction
对这个具体反应来说，选择特性和放热特性关联起来了。

egress是什么意思：
n. 外出；运出；出口
v. （使）外出

The act or process of emerging;egress.
外出出现的动作或过程；出

Forth from the hall egressed the bands.
乐队从大厅里走了出来。

Drains achieve a ready egress of the liquid blood.
引流能为血液提供一个容易的出口。

heat是什么意思：
n. 热；强烈的感情
v. 使变热或变暖；使激动

incomplete heat
不完全发情

heating installation
暖气设备|供暖装置

at a white heat
在盛怒之下|在感情万分激动之下

giving是什么意思：
v. [give] 的现在分词形式；给，交付，授予

Will you give it a shot?
你想做尝试吗？

He gives twice who gives quickly

The purpose is not to give an exhaustive treatment.
其目的并不是给出全面彻底的处理。