| 词或词组 | 中文 | 英文解释中文解释 |
|---|---|---|
| A-basis | A-基础 |
Mechanical property value above which at least 99% of the population of values is expected to fall, with a confidence of 95%. Also called A-allowable. 机械性能值超过该值时，至少99%的值预计会下降，置信度为95%。也被称为A-容许。 |
| Abelian group | 阿贝尔群 |
Property of a group of elements associated with a binary operation. In an Abelian group, the group elements commute under the binary operation. If a and b are any two group elements and if the (+) sign denotes the binary operation, then, for an Abelian group, 与二元运算相关的一组元素的属性。在阿贝尔群中，群元素在二元运算下交换。如果a和b是任意两个群元素并且（+）符号表示二元运算 |
| Ablation cooling | 烧蚀冷却 |
The cooling of a surface exposed to very high external gas temperature which causes the surface material to sublime, melt or decompose. The chemical process absorbs heat while the mass flow of material away from the surface blocks the heat flux from the hot gas. 冷却暴露于非常高的外部气体温度的表面，导致表面材料升华、熔化或分解。化学过程吸收热量，而远离表面的物质的质量流阻挡了来自热气体的热通量。 |
| Ablative materials | 烧蚀材料 |
Materials, especially coating materials, designed to provide thermal protection to a body in a fluid stream through the loss of mass. 材料，尤其是涂层材料，旨在通过质量损失为流体流中的物体提供热保护。 |
| Abradant | 研磨剂 |
The differently sized grits of hard materials such as emery employed for grinding, polishing, etc. The abrasive grade is determined by the grit size (grit number) originally related to the hole sizes in wire sieves. 用于研磨、抛光等的硬质材料（例如金刚砂）的不同尺寸粒度。磨料等级由最初与金属丝筛孔尺寸相关的粒度（粒度数）决定。 |
| Abrasion | 磨损 |
The removal of surface material by the scratching action of hard particles, either deliberately (abrasive papers, abrasive cleaning, abrasive machining) or as a consequence of operation (wear). 通过硬质颗粒的刮擦作用去除表面材料，可以是故意的（砂纸、研磨清洁、研磨加工），也可以是操作的结果（磨损）。 |
| Abrasive wear | 磨料磨损 |
The removal or displacement of material from a surface when hard particles slide or roll across the surface under pressure. The particles may be loose or may be part of another surface in contact with the surface being worn. Contrast with adhesive wear. 当硬质颗粒在压力下在表面上滑动或滚动时，材料从表面上的去除或位移。颗粒可能是松散的或可能是与被磨损表面接触的另一个表面的一部分。与粘着磨损形成对比。 |
| Abrasivity | 磨蚀性 |
The extent to which a surface, particle, or collection of particles will tend to cause abrasive wear when forced against a solid surface under relative motion and under prescribed conditions. 在相对运动和规定条件下，一个表面、颗粒或颗粒集合在被迫抵靠固体表面时趋向于引起磨粒磨损的程度。 |
| ABS polymer | ABS聚合物 |
A class of thermoplastic co-polymer consisting of the three monomers acrylonitrile, butadiene and styrene that has improved properties (particularly toughness) over the individual constituents. 一类由丙烯腈、丁二烯和苯乙烯三种单体组成的热塑性共聚物，其性能（特别是韧性）优于单个成分。 |
| Absolute expansion | 绝对扩张 |
The true volumetric expansion of a liquid with temperature, after account is taken of any expansion of the container in which it is held. 考虑到容纳液体的容器的任何膨胀后，液体随温度的真实体积膨胀。 |
| Absolute humidity | 绝对湿度 |
The weight of water vapor in a gadwater vapor mixture per unit volume of space occupied, expressed, for example, in grains or pounds per cubic foot. 单位体积空间占用的水蒸气混合物中水蒸气的重量，例如，以谷物或磅/立方英尺表示。 |
| Absolute manometer | 绝对压力计 |
A manometer that measures absolute pressure, i.e. pressure measured relative to a perfect vacuum. Absolute pressure cannot be negative. 测量绝对压力的压力计，即相对于完美真空测量的压力。绝对压力不能为负。 |
| Absolute pressure | 绝对压力 |
1. The pressure measured relative to zero pressure (vacuum). 2. Gage pressure plus barometric pressure in the same units. 1.相对于零压力（真空）测量的压力。2.表压加上大气压力的单位相同。 |
| Absolute rating | 绝对标称值 |
A theoretical size designation which is an estimation of the largest particle, by length, that can pass through a filter with a specific 一个理论尺寸名称，它是按长度估算的最大颗粒，它可以通过具有特定过滤器的过滤器 |
| Absolute specific gravity | 绝对比重 |
The ratio of the weight of any volume of a substance to the weight of an equal volume of a reference substance at the same temperature, often water at 4°C, both measured in a vacuum to avoid any effect of buoyancy. 在相同温度下，任何体积的物质的重量与等体积的参考物质的重量之比，通常是4°C的水，两者都是在真空中测量的，以避免任何浮力的影响。 |
| Absolute stability | 绝对稳定 |
Condtion of a linear system in which there exists a limiting value of the open-loop gain such that the system is stable for all lower values of that gain, and unstable for all higher values. 线性系统的条件，其中存在开环增益的限制值，使得系统对于该增益的所有较低值都是稳定的，而对于所有较高值来说都是不稳定的。 |
| Absolute temperature (Unit K) | 绝对温度（单位K） |
A temperature T measured relative to absolute zero, 0 K or −273.15°C, the lowest temperature achievable at which molecular motion vanishes so that a body would have zero heat energy. The kelvin is equal in magnitude to the degree Celsius (°C). The kelvin temperature scale (kelvin absolute temperature scale) is an absolute or thermodynamic temperature scale derived from the Celsius scale: T(K) = T(°C) + 273.15. The Rankine absolute scale is derived from the Fahrenheit scale such that T(R) = T(°F) + 459.67, i.e. a scale relative to 0 R or −459.67°F where R is the Rankine degree symbol and °F is the Fahrenheit symbol. 相对于绝对零、0K或0K测量的温度T−273.15°C，分子运动消失的最低温度，因此物体的热能为零。开尔文的大小等于摄氏度（℃）。开尔文温度标度（开尔文绝对温度标度）是从摄氏标度得出的绝对或热力学温度标度：T（K）=T（°C）+273.15。兰金绝对标度是从华氏标度得出，使得T（R）=T（°F）+459.67，即相对于0R或0R的标度−459.67°F，其中R是朗肯度符号，°F是华氏度符号。 |
| Absolute value error | 绝对值误差 |
The magnitude of the error dlsregarding the algebraic sign, or, for a vectorial error, disregarding its function. 关于代数符号的误差幅度，或者，对于矢量误差，不考虑其函数。 |
| Absolute viscosity | 绝对粘度 |
A measure of the internal shear properties of fluids, expressed as the tangential force per unit area at either of two horizontal planes separated by one unit thickness of a given fluid, one of the planes being fixed and the other moving with unit velocity. 流体内部剪切特性的量度，表示为两个水平面中的任何一个上的单位面积切向力，两个水平面被给定流体的一个单位厚度隔开，其中一个平面固定，另一个以单位速度移动。 |
| Absolute zero | 绝对零度 |
Temperature of -273.16″C or 459.69″F or OK at which molecular motion vanishes and a body has no heat energy. 温度为-273.16″C或459.69″F，此时分子运动消失且物体没有热能。 |
| Absorber | 吸收器 |
1. An auxiliary vibratory system that favourably modifies the vibration characteristics of a main system. 2. Part of an absorption refrigeration system in which the refrigerant is absorbed by a transport medium. 3. The absorber plate is the receiver of a concentrating solar collector where the radiation is absorbed. 1.一种辅助振动系统，可有利地改变主系统的振动特性。2.吸收式制冷系统的一部分，其中制冷剂被传输介质吸收。3.吸收板是吸收辐射的聚光太阳能集热器的接收器。 |
| Absorptance | 吸收率 |
(absorptivity, absorption coefficient, α) The fraction of radiant flux incident on a surface that is absorbed by the surface. The term also applies to absorption of radiation by a volume of fluid. For a semi-transparent surface, α + ρ + τ = 1, where ρ is the reflectance and τ is the transmittance. （吸收率，吸收系数，α）入射到表面的辐射通量被表面吸收的部分。该术语也适用于一定体积的流体对辐射的吸收。对于半透明表面，α+ρ+τ=1，其中ρ是反射率，τ是透射率。 |
| Absorption | 吸收 |
The process whereby a fluid permeates a porous solid, or a gas is dissolved by a liquid. 流体渗透多孔固体或气体被液体溶解的过程。 |
| Absorption dynamometer | 吸收式测功机 |
A dynamometer in which input work or power is dissipated by mechanical friction, electrical resistance, hydraulic resistance, etc. 通过机械摩擦、电阻、液压阻力等耗散输入功或功率的测功机。 |
| Absorption hygrometer | 吸收式湿度计 |
An instrument that determines the content of water vapour in the atmosphere by it being absorbed into a hygroscopic medium. 通过吸收到吸湿介质中来确定大气中水蒸气含量的仪器。 |
| Accelerated testing | 加速测试 |
A type of testing, for rates of wear, fatigue, corrosion etc., in which failure times are reduced by employing greater loads, more frequent power cycling, higher vibration levels, higher humidity, higher temperatures, greater potential differences etc. than would be encountered in normal operation. 一种测试类型，用于测试磨损率、疲劳率、腐蚀率等，通过采用比正常运行中更大的负载、更频繁的功率循环、更高的振动水平、更高湿度、更高温度、更大的电位差等，减少故障时间。 |
| Acceleration due to gravity | 重力加速度 |
(acceleration of free fall, gravitational acceleration, g) (Unit m/s²) The acceleration of a freely-falling body in a vacuum, with a mean value at sea level of approximately 9.81 m/s². （自由落体加速度，重力加速度，g）（单位m/s²）自由落体在真空中的加速度，在海平面处的平均值约为9.81m/s²。 |
| Acceleration-error constant | 加速度误差常数 |
When the reference (demand) input to a control system is parabolic, the output signal will also be parabolic in steady state. The signal that is constant in this situation is the acceleration and thus for a parabolic input the steady-state error, referred to as the acceleration-error constant, is the error in the acceleration. 当控制系统的参考（需求）输入是抛物线时，输出信号在稳定状态下也将是抛物线。在这种情况下恒定的信号是加速度，因此对于抛物线输入，称为加速度误差常数的稳态误差是加速度中的误差。 |
| Accommodation | 适应能力 |
The ability of a robot to respond to changes in the environment. 机器人对环境变化做出反应的能力。 |
| Achme thread | Achme螺纹 |
A screw thread having an included angle of 29° and largely used for feed screws on machine tools. 一种夹角为29°的螺纹，主要用于机床上的进给丝杠。 |
| Acicular ferrite | 针状铁素体 |
A highly substructured non-equiaxed ferrite that forms upon continuous cooling by a mixed diffusion and shear mode of transformation that begins at a temperature slightly higher than the temperature transformation range for upper bainite. It is distinguished from bainite in that it has a limited amount of carbon available; thus, there is only a small amount of carbide present. Ferrite crystallite growing, apparently, as in the course of bainitic transformation. It has a lath-like shape and an increased dislocation 一种高度亚结构的非等轴铁素体，在连续冷却时通过混合扩散和剪切相变模式形成，其开始温度略高于上贝氏体的温度转变范围。它与贝氏体的区别在于它的碳含量有限。因此，仅存在少量碳化物。显然，铁素体微晶在贝氏体转变过程中生长。它具有板条状的形状和增加的位错。 |
| Acid rain | 酸雨 |
Any form of precipitation, including rain, snow, sleet, fog, dew, and particulates, which contains higher than normal levels of sulfuric and nitric acids. These acids result from natural and man-made emissions of sulfur dioxide and oxides of nitrogen, respectively. Acid soot consists of unburned carbon particles, typically larger than 10 μm, in the atmosphere contaminated with sulfuric acid. The particles result from poor combustion of fossil fuels. 任何形式的降水，包括雨、雪、雨夹雪、雾、露水和颗粒物，其中含有高于正常水平的硫酸和硝酸。这些酸分别来自二氧化硫和氮氧化物的自然排放和人为排放。酸烟灰由未燃烧的碳颗粒组成，通常大于10微米，在被硫酸污染的大气中。这些颗粒是化石燃料燃烧不良造成的。 |
| Ackerman linkage | 阿克曼装置 |
A steering linkage on a motor vehicle that approximately gives rolling without slipping of both wheels about the turning point. This is achieved by having the inner stub axle (on the inside of the turning curve) move through a greater angle than the outer stub axle. 机动车辆上的一种转向联动装置，在转向点附近两个车轮几乎不会打滑。这是通过使内短轴（在转弯曲线的内侧）比外短轴移动更大的角度来实现的。 |
| Acoustic droplet ejection | 声液滴喷射 |
The ejection of small droplets from the surface of a liquid that results from focusing high-intensity ultrasound near the surface. 由于在表面附近聚焦高强度超声波而从液体表面喷射出小液滴。 |
| Acoustic emission | 声发射 |
(stress-wave emission) Sound emitted by some materials when deformed under load. It arises from stress waves emitted by sudden dislocation motion in crystals, slip, crack growth, etc. （应力波发射）某些材料在负载下变形时发出的声音。它是由晶体中突然的位错运动、滑移、裂纹扩展等发出的应力波引起的。 |
| Acoustic power | 声功率 |
(sound power) (Unit W) The rate of flow of acoustic energy across a specified surface. （声功率）（单位W）声能流过指定表面的速率。 |
| Acoustic pyrometer | 声学高温计 |
A non-intrusive pyrometer based on the principle that the sound speed in a gas is proportional to the square root of its absolute temperature. 一种非侵入式高温计，其原理是气体中的声速与其绝对温度的平方根成正比。 |
| Acoustic separation | 声学分离 |
(Unit m) The separation of particles in a fluid using standing acoustic waves, typically ultrasound, to drive them to nodal points (acoustic particle concentration). （单位m）使用驻声波（通常是超声波）将流体中的粒子分离，以将它们驱动到节点（声学粒子浓度）。 |
| Acoustics | 声学 |
The science and engineering of sound; its production, propagation, control, interaction with materials, etc. 声音科学与工程；它的产生、传播、控制、与材料的相互作用等。 |
| Activation energy | 活化能 |
(Ea, U) (Unit kJ/mol) The minimum energy for a chemical reaction to occur or for processes such as diffusion to take place in crystals. （Ea, U）（单位kJ/mol）发生化学反应或在晶体中发生扩散等过程的最小能量。 |
| Active accommodation | 主动适应能力 |
The use of information from sensors, for example, in a vision system, that allows a robot to show accommodation to the environment. 使用来自传感器的信息，例如在视觉系统中，允许机器人显示对环境的适应。 |
| Active vibration suppression | 主动振动抑制 |
The reduction of undesirable vibration in components by feedback control. 通过反馈控制减少部件中的不良振动。 |
| Actual cubic feet per minute | 实际立方英尺每分钟 |
(acfm) An obsolete (i.e. non-SI) measure of volumetric flow rate; the volume of a gas flowing per minute at actual operating pressure and temperature, as opposed to the corresponding volume flow rate at STP. （acfm）已被淘汰的（即非SI）体积流量测量；在实际工作压力和温度下每分钟流动的气体体积，与STP下的相应体积流量相反。 |
| Actual power | 实际功率 |
(actual horsepower) (Unit W or hp) The power delivered at the output shaft of an engine, before subsequent transmission through a gearbox etc. （实际马力）（单位W或hp）在随后通过变速箱等传输之前，在发动机输出轴上传递的功率。 |
| Actual value | 实际价值 |
The output of a plant that is being controlled, i.e. the controlled variable. Not directly accessible by the control system, as it can only be measured by a sensor which may distort the measurement. 受控设备的输出，即受控变量。控制系统不能直接访问，因为它只能由可能会扭曲测量结果的传感器测量。 |
| Actuating system | 驱动系统 |
A system in which an electrical, pneumatic or hydraulic input supplied to an actuator produces force, torque, or displacement, usually in a controlled way. 一种系统，其中提供给执行器的电气、气动或液压输入通常以受控方式产生力、扭矩或位移。 |
| Adhesive joint | 粘合接头 |
The point or area in which two structures are held together by an adhesive. 两个结构通过粘合剂粘合在一起的点或区域。 |
| Adhesive strength | 粘合强度 |
The strength of an adhesively bonded joint, usually measured in tension (perpendicular to the plane of the bonded joint) or in shear 粘合接头的强度，通常以拉伸（垂直于粘合接头的平面）或剪切测量 |
| Adhesive wear | 粘着磨损 |
Wear that develops when two surfaces slide across one another under pressure. The removal or displacement of material from a surface by the welding together and subsequent shearing of minute areas of two surfaces that slide across each other under pressure. In advanced stages, may lead to galling. Contrast with abrasive wear. 当两个表面在压力下相互滑动时产生的磨损。通过焊接在一起并随后剪切在压力下相互滑动的两个表面的微小区域，从表面去除或置换材料。在晚期，可能会导致擦伤。与磨料磨损形成对比。 |
| Aerated bath nitriding | 空气搅拌液体渗氮法 |
A type of liquid nitriding in which air is pumped through the molten bath creating agitation and increased chemical activity. 一种液体氮化，其中空气被泵入熔池，产生搅拌并增加化学活性。 |
| Age hardening | 时效硬化 |
Raising the strength and hardness of an alloy by heating a supersaturated solid solution at a relatively low temperature to induce precipitation of a finely dispersed second phase. Also known as aging or precipitation hardening. Hardening by aging, usually after rapid cooling or cold working. 通过在相对较低的温度下加热过饱和固溶体以诱导细分散的第二相沉淀来提高合金的强度和硬度。也称为时效或沉淀硬化。通常在快速冷却或冷加工后。 |
| Age softening | 时效软化 |
Spontaneous decrease of strength and hardness that takes place at room temperature in certain strain hardened alloys, especially those of aluminum. 某些应变硬化合金，尤其是铝合金，在室温下会发生强度和硬度的自发降低。 |
| Aging treatment | 时效处理 |
Heat treatment aimed at age hardening; it comprises solution and precipitation treatments. 针对时效硬化的热处理；它包括溶液和沉淀处理。 |
| Air classifier | 空气分级机 |
(air elutriator) A device in which an airstream, which may be swirling, sorts particles by a combination of size, shape, and mass. （空气淘析器）一种装置，在该装置中，气流（可能是漩涡）根据大小、形状和质量的组合对颗粒进行分类。 |
| Air cleaner | 空气净化器 |
A device, such as a filter, hydrocyclone, or electrostatic precipitator, that removes particles and aerosols from a flow of air. 一种设备，例如过滤器、水力旋流器或静电除尘器，用于从气流中去除颗粒和气溶胶。 |
| Air composition | 空气成分 |
The sea-level composition (in per cent by volume) of air at a temperature of 15°C and a pressure of 1 atm is mainly 78.084% nitrogen, 20.947% oxygen and 0.934% argon. The remaining 0.035% consists of carbon dioxide, neon, helium, methane, krypton, hydrogen, oxides of nitrogen, xenon, ozone, iodine, carbon monoxide, and ammonia. Different sources give slightly different figures for the composition. Not included are water vapour (typically 0.4%) and pollutants such as sulfur dioxide. 在15°C的温度和1个大气压的压力下，空气的海平面成分（体积百分比）主要是78.084%的氮气、20.947%的氧气和0.934%的氩气。剩余的0.035%由二氧化碳、氖、氦、甲烷、氪、氢、氮的氧化物、氙、臭氧、碘、一氧化碳和氨组成。不同的来源给出的组成略有不同。不包括水蒸气（通常为0.4%）和二氧化硫等污染物。 |
| Air compressor | 空气压缩机 |
A turbomachine that draws in air and delivers it at higher pressure, temperature, and density. It can be of axial, fan, reciprocating, or rotary design. 一种涡轮机，它吸入空气并以更高的压力、温度和密度输送空气。它可以是轴流式、风扇式、往复式或旋转式设计。 |
| Air conditioning | 空调 |
The process of controlling the temperature and humidity in rooms, buildings, aircraft, passenger vehicles, etc. More generally it includes control of dust, levels of radiant heat, etc. 控制房间、建筑物、飞机、客运车辆等的温度和湿度的过程。更一般地说，它包括控制灰尘、辐射热水平等。 |
| Air pump | 气泵 |
A machine for providing a flow of air or for increasing or decreasing the mass and pressure of air in a closed container. The term pump is more usual when the working fluid is a liquid, while compressor is more usual for gases. 一种用于提供空气流动或用于增加或减少密闭容器中空气质量和压力的机器。当工作流体是液体时，术语泵更常用，而气体更常用压缩机。 |
| Air-cooled condenser | 风冷冷凝器 |
A heat exchanger, in which the cooling medium is air, used to condense the exhaust steam from a steam turbine, the condensate being returned to the boiler. 一种热交换器，其中冷却介质为空气，用于冷凝蒸汽轮机排出的蒸汽，冷凝水返回锅炉。 |
| Air-cooled engine | 风冷发动机 |
An internal-combustion engine directly cooled by airflow, rather than by water flowing through the engine block being cooled by a radiator. 一种由气流直接冷却的内燃机，而不是通过流经发动机缸体的水被散热器冷却。 |
| Air-hardening steel | 空气硬化钢 |
A steel containing sufficient carbon and other alloying elements to harden fully during cooling in air or other gaseous mediums from a temperature above its transformation range. The terms should be restricted to steels that are capable of being hardened by cooling in air in fairly large sections, about 2 in. (50 mm) or more in diameter. Same as self-hardening steel. 一种钢，含有足够的碳和其他合金元素，可以在空气或其他气体介质中从高于其转变范围的温度冷却过程中完全硬化。这些术语应仅限于能够通过在相当大的截面（直径约2英寸（50毫米）或更大）中通过空气冷却而硬化的钢。与自硬钢相同。 |
| AISC | AISC |
The American Institute of Steel Construction. 美国钢结构学会。 |
| Allotropy | 同素异形体 |
A near synonym for polymorphism. Allotropy is generally restricted to describing polymorphic behavior in elements, terminal phases, and alloys whose behavior closely parallels that of the predominant constituent element. 多态性的近义词。同素异形体通常仅限于描述元素、终端相和合金中的多晶型行为，其行为与主要组成元素的行为非常相似。 |
| Allowable stress | 许用应力 |
The maximum stress a designer can assume that the parts will stand. It is always less than the minimum strength of the material. For example, the ASME Boiler and Pressure Vessel Code typically specifies an allowable stress that is one-quarter of the service temperature yield strength of the material. This introduces a four-to-one safety factor into the design process and is intended to compensate for uncertainties in estimates of strength, service loads, etc. 设计师可以假设零件能够承受的最大应力。它总是小于材料的最小强度。例如，ASME锅炉和压力容器规范通常指定允许应力为材料使用温度屈服强度的四分之一。这在设计过程中引入了四比一的安全系数，旨在补偿强度、服务载荷等估计的不确定性。 |
| Allowable stress design | 许用应力设计 |
A design procedure developed for the AISC by the Research Council on Structural Connections. Purposely underestimates the strengths of bolts and joint materials to introduce safety factors into the design of structural steel joints. It is an alternative to the more recently defined load and resistance factor design procedure. 结构连接研究委员会为AISC制定的设计程序。故意低估螺栓和接头材料的强度，以便在结构钢接头的设计中引入安全系数。它是最近定义的荷载和阻力系数设计程序的替代方法。 |
| Alloy | 合金 |
1. A metallic material composed of two or more elements, one of which is usually a metal to which the other elements are added, e.g. iron-carbon or aluminium-copper (binary alloy); nickel-chromium-iron (ternary alloy). 2. A plastic produced as a blend of two or more immiscible polymers. This results in material that cannot be achieved by polymerization. 1.由两种或多种元素组成的金属材料，其中一种通常是添加了其他元素的金属，例如铁碳或铝铜（二元合金）；镍铬铁（三元合金）。2.由两种或多种不混溶聚合物混合而成的塑料。这导致无法通过聚合获得的材料。 |
| Alloy steels | 合金钢 |
Steels that contain alloying elements such as chromium, nickel, molybdenum, manganese, silicon, tungsten, and vanadium. These are added to improve properties such as the hardenability, toughness, strength, wear resistance, and corrosion resistance compared with those of plain-carbon steel. Low-alloy steels have a total alloy content (including carbon) of less than about 8%. They are hardenable and have strength up to 30% higher than plain-carbon steels. High-alloy steels contain considerably more alloy content and are developed for specific properties such as superior corrosion and chemical resistance. 含有铬、镍、钼、锰、硅、钨和钒等合金元素的钢。添加这些是为了提高与普通碳钢相比的淬透性、韧性、强度、耐磨性和耐腐蚀性等性能。低合金钢的总合金含量（包括碳）小于约8%。它们是可硬化的，强度比普通碳钢高出30%。高合金钢含有相当多的合金含量，并针对特定性能而开发，例如卓越的耐腐蚀性和耐化学性。 |
| Alloying element | 合金元素 |
Component added deliberately with the aim of improving the properties of an alloy. Alloying elements can affect the existence range of equilibrium phases present in an unalloyed material, or lead to the occurrence of new phases, or both. In addition, alloying elements strongly affect the kinetics of phase transformations and thus the microstructure formation in alloyed materials. 为改善合金性能而有意添加的成分。合金元素可以影响非合金材料中存在的平衡相的存在范围，或导致新相的出现，或两者兼而有之。此外，合金元素强烈影响相变动力学，从而影响合金材料的微观结构形成。 |
| Alpha iron | 阿尔法铁 |
The body-centered cubic form of pure iron, stable below 910 °C (1670 °F). 纯铁的体心立方形式，在910°C(1670°F)以下稳定。 |
| Alternating stress | 交替应力 |
(Unit Pa) Originally, stresses of changing sign (tension-tocompression-to-tension, etc.) in a component produced by alternating forces acting in opposite directions, but now generally used to describe stresses that vary but may keep the same sign, as produced by periodic, out-of–balance, or vibrational loads. （单位Pa）最初，构件中由相反方向的交变力产生的符号变化的应力（张力到压缩到张力等），但现在通常用于描述变化但可能保持相同符号的应力，如由周期性、失衡或振动载荷产生的应力。 |
| Alternative energy | 可替代能源 |
(alternate energy) Energy sources that are renewable and do not have the undesired consequences of fossil fuels and nuclear energy. （替代能源）可再生能源，不会产生化石燃料和核能的不良后果。 |
| Altitude | 高度 |
(Unit m) Vertical height measured relative to a specified datum such as sea level. （单位m）相对于特定基准（例如海平面）测量的垂直高度。 |
| Altitude chamber | 高空舱 |
(hypobaric chamber) A chamber in which conditions at different altitudes are simulated by a combination of appropriate pressures, temperatures and relative humidity. （低压舱）通过适当的压力、温度和相对湿度的组合来模拟不同高度条件的舱室。 |
| Amontons friction | 阿蒙顿摩擦 |
(Coulomb friction) Friction between surfaces where the ratio of the frictional force F to the normal force N is constant and independent of the area in contact. （库仑摩擦）摩擦力F与法向力N之比恒定且与接触面积无关的表面之间的摩擦。 |
| Amplifier | 放大器 |
A device by which the output of a hydraulic, pneumatic, or electrical source is increased. 增加液压、气动或电源输出的装置。 |
| Anelastic | 无弹性 |
Literally ‘not elastic’, but in practice used for materials that display timedependent recovery on unloading. 字面意思是“没有弹性”，但实际上用于在卸载时显示随时间恢复的材料。 |
| Angle of attack (α) | 攻角（α） |
(Unit °) The angle between a reference line on a lifting body and the vector direction of the relative velocity between the body and the fluid through which it is moving. In the case of an aerofoil, turbine, or compressor blade, the usual reference line is the chord line. （单位°）升力体上的参考线与升力体与其运动通过的流体之间的相对速度的矢量方向之间的角度。在机翼、涡轮或压缩机叶片的情况下，通常的参考线是弦线。 |
| Angle of contact | 接触角 |
(Unit °) The angle subtended at the centre of a pulley or sprocket wheel by the circumferential contact of a belt or chain. （单位°）皮带或链条的圆周接触在皮带轮或链轮的中心所对的角度。 |
| Angle of friction | 摩擦角 |
(friction angle, β) (Unit °) For a body in contact with a plane surface, the angle between the normal to the surface and the resultant force between the body and the surface. If the friction force is F and normal force is N, β is given by F/N = μ = tan β where μ is the coefficient of friction. （摩擦角，β）（单位°）对于与平面接触的物体，表面法线与物体与表面之间的合力之间的夹角。如果摩擦力为F，法向力为N，则β由F/N=μ=tanβ给出，其中μ是摩擦系数。 |
| Angle of thread | 螺纹角度 |
The included angle between the sides forming the groove of the screw thread. 形成螺纹凹槽的边之间的夹角。 |
| Angle of torsion | 扭转角 |
(angle of twist) (Unit ° or rad) The angle relative to a chosen section, normal to the axis of twist, through which another part of a component rotates when subjected to a torque. （扭转角）（单位°或弧度）相对于选定截面的角度，垂直于扭转轴，部件的另一部分在受到扭矩时通过该角度旋转。 |
| Angström (Å) | 昂斯特罗姆（Å） |
An obsolete (non-SI) unit of length, sometimes still employed for atomic and crystallographic measurements. The conversion to SI is 1 Å = 10−10 m. 一种已被淘汰的（非SI）长度单位，有时仍用于原子和晶体学测量。转换为SI为1Å=10-10m。 |
| Angularity | 角度 |
The underfaces of the nut and the bolt head should be exactly perpendicular to the thread or shank axes. If the angle between the face and the axis is, for example, 868 or 948, the fastener is said to have an angularity of 48 (sometimes called Perpendicularity). 螺母和螺栓头的底面应与螺纹或柄轴完全垂直。例如，如果面和轴之间的角度为868或948，则称紧固件的角度为48（有时称为垂直度）。 |
| Anisotropy | 各向异性 |
The characteristic of exhibiting different values of a property in different directions with respect to a fixed reference system in the material. 相对于材料中的固定参考系统，在不同方向上表现出不同属性值的特性。 |
| Anneal to temper | 退火回火 |
A final partial anneal that softens a cold worked nonferrous alloy to a specified level of hardness or tensile strength. 将冷加工的有色金属合金软化到规定的硬度或抗拉强度水平的最终局部退火。 |
| Annealing | 退火 |
A generic term denoting a treatment, consisting of heating to and holding at a suitable temperature followed by cooling at a suitable rate, used primarily to soften metallic materials, but also to simultaneously produce desired changes in other properties or in microstructure. 一个通用术语，表示一种处理，包括加热并保持在合适的温度，然后以合适的速率冷却，主要用于软化金属材料，但也同时产生其他性能或微观结构的所需变化。 |
| Annealing carbon | 退火碳 |
Fine, apparently amorphous carbon particles formed in white cast iron and certain steels during prolonged annealing. Also called temper carbon. 白口铸铁和某些钢在长时间退火过程中形成的细小、明显的无定形碳颗粒。也称为回火碳。 |
| Annealing twin | 退火孪晶 |
A twin form in a crystal during recrystallization. 重结晶过程中晶体中的孪晶形式。 |
| Anode | 阳极 |
That electrode in a battery or corrosion cell which produces electrons. It is the electrode which is destroyed (corrodes). 电池或腐蚀电池中产生电子的电极。被破坏（腐蚀）的是电极。 |
| ANSI | ANSI |
The acronym for American National Standards Institute. 美国国家标准协会的缩写。 |
| Anti-freeze | 防冻液 |
A substance such as ethylene glycol added to the cooling system of a watercooled engine to lower the freezing point of the cooling water and also inhibit the formation of rust and other deposits. 一种物质，如乙二醇，添加到水冷发动机的冷却系统中，以降低冷却水的冰点，并抑制生锈和其他沉积物的形成。 |
| Apparent area of contact | 表观接触面积 |
In tribology, the area of contact between two solid surfaces defined by the boundaries of their macroscopic interface. 在摩擦学中，两个固体表面之间的接触区域由其宏观界面的边界定义。 |
| Applied thermodynamics | 应用热力学 |
(engineering thermodynamics, thermodynamics) The science of the relationship between heat, work and the properties of systems and the ways in which heat energy from fuels can be converted into mechanical work. It involves the study of all aspects of energy use and energy transformation, including power generation, refrigeration, the relevant properties of the substances involved and the relationships between them. The principle of conservation of energy is a fundamental law of nature. （工程热力学、热力学）热、功和系统特性之间关系的科学，以及燃料中的热能可以转化为机械功的方式。它涉及能源使用和能源转换的各个方面的研究，包括发电、制冷、所涉及物质的相关特性以及它们之间的关系。能量守恒定律是自然的基本规律。 |
| Arbitration bar | 抗弯试棒 |
A test bar, cast with a heat of material, used to determine chemical composition, hardness, tensile strength, and deflection and strength under transverse loading in order to establish the state of acceptability of the casting. 用热材料铸造的测试棒，用于确定化学成分、硬度、抗拉强度、横向载荷下的挠度和强度，以确定铸件的可接受状态。 |
| Archimedes screw | 阿基米德螺旋泵 |
A machine which comprises a rotating helical blade inside a closefitting tube, which may be used to pump liquids, slurries (such as sewage), granular materials, etc. If water flows into the top of an inclined or vertical Archimedes screw, the screw will rotate and can be used to drive an electrical generator. 一种机器，它在紧密的管子内包含一个旋转的螺旋叶片，可用于泵送液体、泥浆（如污水）、颗粒材料等。如果水流入倾斜或垂直的阿基米德螺杆的顶部，螺杆将旋转，可用于驱动发电机。 |
| Archimedes Wave Swing | 阿基米德波摆动 |
A machine for tidal-power energy generation consisting of two concentric, air-filled submerged cylinders. The inner lower cylinder is tethered to the ocean floor while the upper floater unit, which is closed at the top, moves up and down due to the variations in hydrostatic pressure caused by the wave motion. The relative movement of the two cylinders is used to generate electricity in which linear motion replaces the more common rotary motion of an electromagnetic generator. 一种用于潮汐能发电的机器，由两个同心的充气水下气缸组成。内部下部圆柱体系在海底，而顶部封闭的上部浮子单元由于波浪运动引起的静水压力变化而上下移动。两个气缸的相对运动用于发电，其中直线运动取代了电磁发电机更常见的旋转运动。 |
| Artificial aging | 人工时效 |
Aging above room temperature. 在室温以上的时效。 |
| ASME | ASME |
The American Society of Mechanical Engineers. 美国机械工程师学会。 |
| Aspect ratio | 纵横比 |
The ratio of the longest to the shortest dimension of a shape or object e.g. the chord-to-thickness ratio of an aerofoil or the span-to-chord ratio of a wing. 形状或物体的最长与最短尺寸之比，例如机翼的弦厚比或机翼的翼展弦比。 |
| Assembly drawing | 装配图纸 |
An engineering drawing that shows how parts are assembled to produce a component or a complete machine. It may include sections to show internal features, dimensions that are critical for assembly, manufacturing information, and part numbers. 显示零件如何组装以生产组件或整机的工程图。它可能包括显示内部特征、对装配至关重要的尺寸、制造信息和零件编号的部分。 |
| Assembly line | 流水线 |
A system of mass production in which work is moved progressively from one operation to another, ultimately to give the final complete product. 一种大规模生产系统，其中工作逐渐从一个操作转移到另一个操作，最终得到完整产品。 |
| Athermal transformation | 非热变化 |
A reaction that proceeds without benefit of thermal fluctuations; that is, thermal activation is not required. In contrast, a reaction that occurs at constant temperature is an isothermal transformation; thermal activation is necessary in this case and the reaction proceeds as a function of time. 在没有热波动的情况下进行的反应；也就是说，不需要热激活。相反，在恒温下发生的反应是等温转变。在这种情况下，热活化是必要的，并且反应作为时间的函数进行。 |
| Atmometer | 气压计 |
(atmidometer, evaporimeter) An instrument that measures the rate of evaporation of water from a surface into the atmosphere. （湿度计，蒸发计）测量水从表面蒸发到大气中的速率的仪器。 |
| Atmosphere | 大气 |
1. (atm) An obsolete (non-SI) unit of pressure equal to 101 325 Pa or 1.013 25 bar and approximately equal to the atmospheric pressure (barometric pressure) measured at mean sea level. 1.（atm）一种已被淘汰的（非SI）压力单位，等于101325Pa或1.01325bar，大约等于在平均海平面测量的大气压力（大气压）。 |
| Atmospheric pressure | 气压 |
The downward force exerted by the atmosphere because of its weight, (gravitational attraction to the Earth), measured by barometers, and usually expressed in units of millibars. Standard atmospheric pressure at sea level is 1013.25 mb.expressed in units of millibars. Standard atmospheric pressure at sea level is 1013.25 mb. 大气由于其重量（对地球的引力）而施加的向下的力，用气压计测量，通常以毫巴为单位表示。海平面的标准大气压为1013.25mb。以毫巴为单位表示。海平面的标准大气压为1013.25mb。 |
| Atom | 原子 |
The smallest unit of matter that has the properties of a chemical element. The simplest description of an atom (Bohr model) is of a compact nucleus surrounded by one or more orbiting electrons. 具有化学元素性质的最小物质单位。原子的最简单描述（玻尔模型）是由一个或多个轨道电子包围的致密原子核。 |
| Atomic volume | 原子体积 |
Volume of unit cell per atom. 每个原子的晶胞体积。 |
| Atomization | 雾化 |
The production of a spray of fine droplets from a liquid, such as diesel oil or petrol, by injection through a nozzle (an atomizer). 通过喷嘴（雾化器）喷射从液体（例如柴油或汽油）中产生细小液滴喷雾。 |
| Atomizing humidifier | 雾化加湿器 |
A humidifier that functions by spraying fine droplets of water into an airstream. 一种加湿器，通过将细小的水滴喷射到气流中来发挥作用。 |
| Ausforming | 形变热处理 |
Thermomechanical treatment of steel in the metastable austenitic condition below the recrystallization temperature followed by quenching to obtain martensite and/or bainite. 在低于再结晶温度的亚稳态奥氏体条件下对钢进行热机械处理，然后淬火以获得马氏体和/或贝氏体。 |
| Austempered steels | 等温钢 |
Medium to high carbon steels with improved mechanical properties as a result of austempering. After heating to between 800° and 900°C to form the austenite phase, they are quenched to, and held at, just above the martensite transformation range (between 260° and 370°C) to form bainite, before cooling further. Austempering of ductile cast irons results in a microstructure of bainite and spheroidal graphite. Austempered ductile irons have excellent toughness and wear properties. 由于等温淬火，机械性能得到改善的中高碳钢。在加热到800°和900°C之间形成奥氏体相后，将它们淬火并保持在略高于马氏体转变范围（260°和370°C之间）以形成贝氏体，然后进一步冷却。球墨铸铁的等温淬火导致贝氏体和球状石墨的微观结构。等温淬火球墨铸铁具有优异的韧性和耐磨性。 |
| Austempering | 等温淬火 |
A heat treatment for ferrous alloys in which a part is quenched from the austenitizing temperature at a rate fast enough to avoid formation of ferrite or pearlite and then held at a temperature just above Ms until transformation to bainite is complete. Although designated as bainite in both austempered steel and austempered ductile iron (ADI), austempered steel consists of two phase mixtures containing ferrite and carbide, while austempered ductile iron consists of two phase mixtures containing ferrite and austenite. Heat treatment comprising austenitization of a steel article, cooling it to a bainitic range at a rate higher than the critical cooling rate and holding at a fixed temperature until the completion of bainitic transformation. 一种铁合金的热处理，其中零件从奥氏体化温度以足够快的速度淬火，以避免形成铁素体或珠光体，然后保持在略高于Ms的温度，直到完全转变为贝氏体。虽然在奥氏体钢和奥氏体球铁(ADI)中都被指定为贝氏体，但奥氏体钢由含有铁素体和碳化物的两相混合物组成，而奥氏体球墨铸铁由含有铁素体和奥氏体的两相混合物组成。热处理包括钢制品的奥氏体化，以高于临界冷却速率的速率将其冷却到贝氏体范围，并保持在固定温度直到贝氏体转变完成。 |
| Austenite | 奥氏体 |
A solid solution of one or more elements in face-centered cubic iron. Unless otherwise designated (such as nickel austenite), the solute is generally assumed to be carbon. Solid solution of alloying elements and/or carbon in γ-Fe. It is named after British metallurgist W. C. Roberts-Austen. 一种或多种元素在面心立方铁中的固溶体。除非另有说明（如镍奥氏体），溶质通常假定为碳。合金元素和/或碳在γ-Fe中的固溶体。它以英国冶金学家WCRoberts-Austen的名字命名。 |
| Austenite finish temperature (Af) | 奥氏体完成温度（Af） |
Temperature at which the transformation of martensite into austenite completes upon heating. The same designation is also applied to nonferrous alloys in which martensite transforms into some parent phase. 加热时马氏体转变为奥氏体的温度。相同的名称也适用于马氏体转变为某些母相的有色合金。 |
| Austenite stabilization | 奥氏体稳定化 |
Decrease, in comparison to a continuous cooling, in the amount of martensite occurring from austenite when cooling is interrupted at a temperature between Ms and Mf. This can be explained by the relaxation of stresses induced in the austenite by martensite crystals occurring before the interruption. The relaxation, in turn, leads to the dislocation rearrangement and their interaction with martensite/austenite interfaces, which makes the interfaces immobile. 与连续冷却相比，当在Ms和Mf之间的温度中断冷却时，从奥氏体中产生的马氏体的量减少。这可以通过中断前发生的马氏体晶体在奥氏体中引起的应力松弛来解释。反过来，松弛导致位错重排及其与马氏体/奥氏体界面的相互作用，这使得界面无法移动。 |
| Austenite-stabilizer | 奥氏体稳定剂 |
Alloying element expanding the γ-phase field in the corresponding phase diagram, which manifests itself in a decrease of the A3 temperature and an increase of the A4 temperature in binary alloys Fe–M as well as in a decrease of A1 temperature in ternary alloys Fe–C–M (M is an alloying element). The solubility of austenite-stabilizers in ferrite is much lower than in austenite. Under the influence of austenite-stabilizers, austenite can become thermodynamically stable down to room temperature. 合金元素扩展了相应相图中的γ相场，这表现为二元合金Fe-M中A3温度的降低和A4温度的升高，以及A1温度的降低三元合金Fe–C–M（M是合金元素）。奥氏体稳定剂在铁素体中的溶解度远低于在奥氏体中的溶解度。在奥氏体稳定剂的影响下，奥氏体可以在低至室温时变得热力学稳定。 |
| Austenitic grain size | 奥氏体晶粒尺寸 |
The size attained by the grains of steel when heated to the austenitic region; may be revealed by appropriate etching of cross sections after cooling to room temperature. 当加热到奥氏体区域时钢晶粒达到的尺寸；冷却至室温后，可通过适当蚀刻横截面来显示。 |
| Austenitic stainless steels | 奥氏体不锈钢 |
Austenitic stainless steels are non-magnetic. They contain significant additions of chromium (16–30%), but have the austenite (FCC) crystal structure, stabilized by the addition of nickel in the composition range 6–20%. Carbon content ranges from about 0.03 to 0.15%. The ‘18–8’ stainless steels containing approximately 18% chromium and 8% nickel are typical of the class. Austenitic stainless steels have high strength and corrosion resistance even at elevated temperatures, good ductility, good low-temperature properties, and good weldability. Used for aircraft and transport equipment, cutlery, chemical and food-processing equipment, surgical instruments, and cryogenic vessels. 奥氏体不锈钢是非磁性的。它们含有显着添加的铬（16–30%），但具有奥氏体（FCC）晶体结构，通过在6–20%的成分范围内添加镍来稳定。碳含量范围约为0.03至0.15%。含有大约18%铬和8%镍的“18-8”不锈钢是该级别的典型不锈钢。奥氏体不锈钢即使在高温下也具有高强度和耐腐蚀性，良好的延展性，良好的低温性能和良好的焊接性。用于飞机和运输设备、餐具、化学和食品加工设备、手术器械和低温容器。 |
| Austenitizing | 奥氏体化 |
Forming austenite by heating a ferrous alloy into the transformation range (partial austenitizing) or above the transformation range (complete austenitizing). When used without qualification, the term implies complete austenitizing. 通过将铁合金加热到转变范围（部分奥氏体化）或高于转变范围（完全奥氏体化）来形成奥氏体。当不加限定地使用时，该术语意味着完全奥氏体化。 |
| Autonomous energy system | 自主能源系统 |
(stand-alone energy system) A sole source of electricity, usually small-scale, for applications remote from a grid, especially with energy storage in the system. Hydroelectric, photovoltaic, wind-power and other renewable systems are well suited to stand-alone applications. （独立能源系统）一种唯一的电力来源，通常是小规模的，用于远离电网的应用，尤其是系统中的能量存储。水电、光伏、风力和其他可再生能源系统非常适合独立应用。 |
| Auxetic materials | 拉胀材料 |
Those man-made materials for which Poisson’s ratio is negative, so that the cross section expands when subjected to a longitudinal tensile stress and contracts when subjected to a longitudinal compressive stress. 泊松比为负的人造材料，其横截面在受到纵向拉应力时会膨胀，在受到纵向压应力时会收缩。 |
| Auxiliary power unit (APU) | 辅助动力装置（APU） |
In aircraft–gas–turbine applications, a small gas turbine used to provide start-up power, electrical and hydraulic power, and compressed air for cabin ventilation. In other applications, an APU may be a gas turbine or internal-combustion engine used to provide emergency power. 在飞机-燃气轮机应用中，小型燃气轮机用于提供启动动力、电力和液压动力以及用于机舱通风的压缩空气。在其他应用中，APU可以是用于提供应急动力的燃气轮机或内燃机。 |
| Available draught (Unit Pa) | 可用通风量（单位Pa） |
The reduced pressure of combustion gases in a furnace or boiler, either forced or due to the buoyancy of hot gases, which is used to draw in combustion air and remove products of combustion. 炉子或锅炉中燃烧气体的压力降低，无论是强制还是由于热气体的浮力，用于吸入燃烧空气并去除燃烧产物。 |
| Available head (Unit m) | 可用水头（单位米） |
In a hydroelectric power system, the difference between the vertical height of the water level in the supply reservoir above the turbine inlet less the head loss due to friction and fittings in the duct leading to the turbine. 在水力发电系统中，水轮机入口上方供水水库中水位垂直高度之间的差减去由于通向涡轮机的管道中的摩擦和配件造成的水头损失。 |
| Available resource | 可用资源 |
(total resource) (Unit J) The total annual energy theoretically available from a renewable-energy source, such as ocean waves, the wind, or the total incident solar energy. （总资源）（单位J）理论上可从可再生能源（例如海浪、风或总入射太阳能）获得的年度总能量。 |
| Avogadro constant | 阿伏伽德罗常数 |
(Avogadro number, NA) A fundamental physical constant with the fixed numerical value 6.022 140 76 × 1023 mol−1. The mole contains exactly this number of elementary entities. A minor adjustment to the value of the Avogadro constant was made effective on 20 May 2019. （阿伏伽德罗数，NA）一个固定数值为6.02214076×1023mol的基本物理常数−摩尔正好包含这个数量的基本实体。对阿伏伽德罗常数值的微小调整于2019年5月20日生效。 |
| Axial load (Unit N) | 轴向载荷（单位N） |
In general, a tensile or compressive load directed along the axis of a component. Strictly the load should pass through the centroid of the cross section to avoid inducing bending moments and be perpendicular to the plane of the section. 通常，沿部件的轴定向的拉伸或压缩载荷。严格来说，载荷应通过横截面的质心以避免产生弯矩并垂直于横截面。 |