Oxy-Acetylene Flame Types

霍尔-埃鲁法是铝冶炼的主要工业方法。该方法包括将氧化铝（Al₂O₃）溶解在熔融的冰晶石（Na₃AlF₆）中，然后电解熔融的盐浴。铝金属沉积在阴极，而氧化铝中的氧气与碳阳极发生反应，生成二氧化碳。这一工艺使得铝的供应更加广泛且价格更加实惠。

一个经验公式，用于描述电池的可用容量如何随着放电率的增加而减少。该定律表示为 [latex]C_p = I^k t[/latex]，其中 [latex]C_p[/latex] 是一安培放电速率下的容量，[latex]I[/latex] 是放电电流，[latex]t[/latex] 是放电时间，[latex]k[/latex] 是针对电池类型的普克特常数。它量化了高负载时的低效率。

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.

Temper embrittlement is a reduction in the toughness of certain alloy steels caused by holding them in, or slowly cooling them through, a specific temperature range (approximately 375–575 °C). This phenomenon is driven by the segregation of impurity elements (e.g., phosphorus, tin, antimony) to the grain boundaries, which weakens the cohesion between grains and promotes intergranular fracture.

For materials that do not have a distinct yield point on their stress-strain curve, like aluminum or high-strength steel, 'proof stress' is the engineering equivalent. It is defined as the stress required to produce a small, specified amount of permanent (plastic) deformation, typically 0.2% of the original gauge length. This value, [latex]\sigma_{0.2}[/latex], is used in design calculations as the material's practical elastic limit.

点状腐蚀是一种局部腐蚀，会在金属上形成小孔或 "凹坑"。点蚀是最具破坏性的腐蚀形式之一，因为它难以检测、预测和设计。点蚀只占总质量损失的一小部分，就能导致结构发生灾难性故障。

Hydrogen embrittlement (HE) is a process where metals, most notably high-strength steels, become brittle and fracture following exposure to hydrogen. Atomic hydrogen diffuses into the metal lattice and reduces its ductility and load-bearing capacity. Key proposed mechanisms include Hydrogen-Enhanced Decohesion (HEDE), which weakens atomic bonds, and Hydrogen-Enhanced Localized Plasticity (HELP), which facilitates dislocation motion and localized failure.

氯碱工艺是一种电解氯化钠 (NaCl) 溶液（又称盐水）的工业方法。它是生产氯气 (Cl₂)、氢氧化钠 (NaOH) 和氢气 (H₂) 的主要来源，而这些产品都是重要的日用化学品。现代方法使用膜电解槽分离阳极和阴极产物，以确保高纯度和高效率。

Exothermic welding, also known as thermite welding, is a technique that uses the superheated molten metal from an aluminothermic reaction to create a strong, permanent molecular bond between metal components. The process is self-contained, requiring no external power source. It is most famously used to join sections of railway track into continuous welded rail, creating a smoother and more durable track.

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.

Gas cylinders for oxy-fuel welding store gases or other industrial or medical gases, at very high pressures. A pressure regulator is essential to reduce this to a safe, usable working pressure. A two-stage regulator performs this reduction in two steps, providing a highly constant delivery pressure even as the cylinder pressure drops with use. This ensures a stable flow, thus a stable flame for consistent weld quality.

Acoustic impedance ([latex]Z[/latex]) is a material's intrinsic resistance to acoustic flow, defined as its density ([latex]\rho[/latex]) multiplied by its acoustic velocity ([latex]c[/latex]), so [latex]Z = \rho c[/latex]. The percentage of ultrasonic energy reflected at the boundary between two materials is governed by the difference, or mismatch, in their respective acoustic impedances. This principle is what makes flaw detection possible.

自働化（Jidoka）通常被翻译为“自动化”或“人性化的自动化”，是丰田生产系统的支柱之一。它授权任何机器或工人在检测到异常或缺陷时立即停止整条生产线。这可以防止大量生产缺陷产品，并立即发现问题，从而分析根本原因并找到永久性解决方案。

生产间隔时间（Takt time）是指为满足客户需求而生产产品所需的最长时间。它的计算方法是用净可用生产时间除以该时间段内的客户需求量。计算公式为：[latex]T = \frac{T_a}{D}[/latex]，其中，T 为工时，Ta 为净可用时间，D 为客户需求。