齐奥尔科夫斯基火箭方程

An empirical formula that describes how the available capacity of a battery decreases as the rate of discharge increases. The law is stated as [latex]C_p = I^k t[/latex], where [latex]C_p[/latex] is the capacity at a one-ampere discharge rate, [latex]I[/latex] is the discharge current, [latex]t[/latex] is the discharge time, and [latex]k[/latex] is the Peukert constant, specific to the battery type. It quantifies the inefficiency at high loads.

火灾三角是一个简单的模型，它描述了大多数火灾发生的三个基本要素：热量、燃料和氧化剂（通常是大气中的氧气）。消除其中任何一个要素，都可以阻止火灾发生或扑灭现有火灾。这是消防安全和预防的基本概念。

速度变化量（Δv），字面意思是“速度变化”，是衡量轨道机动所需冲量的标量。它量化了任务所需的总推进力，与航天器的质量无关。该值对于任务规划至关重要，因为它决定了所需的推进剂装载量。速度变化量是累积的；一次任务的总速度变化量是所有所需机动速度变化量的总和。

Oxy-fuel cutting, or flame cutting, severs ferrous metals by a rapid, exothermic oxidation process. First, a preheating flame raises the steel's surface to its kindling temperature (approx. 870 °C or 1600 °F). A high-pressure jet of pure oxygen is then directed at the spot, initiating a chemical reaction, [latex]3Fe + 2O_2 \rightarrow Fe_3O_4[/latex], which forms molten iron oxide (slag) and releases heat.

The separation factor, α (alpha), quantifies the selectivity of an extraction system for two different solutes, A and B. It is defined as the ratio of their individual distribution ratios, [latex]\alpha_{A,B} = \frac{D_A}{D_B}[/latex]. For a separation to be effective, α must be significantly different from unity. A larger α value implies an easier and more efficient separation.

抽水蓄能水电（PSH）是一种水力储能技术，用于电力系统平衡负荷。该方法将水的重力势能以水力储能的形式储存起来，将水从低海拔水库抽到高海拔水库。在电力需求高峰期，储存的水会被释放，驱动涡轮机发电。

放热焊接，也称为铝热焊接，是一种利用铝热反应产生的过热熔融金属在金属部件之间形成牢固、持久的分子键的技术。该工艺独立运行，无需外部电源。它最著名的用途是将铁路轨道段连接成连续的焊接轨道，从而打造更平整、更耐用的轨道。

Artificial gravity can be created in a spacecraft by rotating the structure. Occupants feel a centrifugal force pushing them towards the outer hull, mimicking gravity. The magnitude of this apparent gravity is given by [latex]a = \omega^2 r[/latex], where [latex]\omega[/latex] is the angular velocity and [latex]r[/latex] is the radius of rotation. This is proposed to counteract the negative health effects of long-term weightlessness.

Oxy-acetylene welding uses a flame produced by the combustion of acetylene ([latex]C_2H_2[/latex]) with pure oxygen. The reaction occurs in two stages. The primary reaction in the inner, white-hot cone is incomplete, producing carbon monoxide and hydrogen: [latex]2C_2H_2 + 2O_2 \rightarrow 4CO + 2H_2[/latex]. These hot gases then react with atmospheric oxygen in the outer envelope, completing the combustion.

氧乙炔火焰的特性取决于氧气与乙炔的体积比。中性火焰（体积比 ≈ 1.1:1）是钢焊接的标准火焰。渗碳火焰或还原火焰（体积比 1.1:1）氧气过剩，温度更高，用于钎焊。

TNT 的一个关键特性是其熔点低，仅为 80.6 °C (177.1 °F)，远低于其 240 °C 的自燃温度。如此大的温差使得 TNT 能够安全地用蒸汽或热水熔化，并浇铸到弹药外壳中，这一过程称为熔铸。这使得生产致密、均匀且无裂纹的炸药成为可能。