第一章词汇:注释:divided by 除以 multiplied by 乘以 meter per square second Vector: [‘vekt?] 矢量 A quantity has magnitude as well as direction.Scalar: [‘skeil?] 标量 A quantity completely defined by its magnitude. average speed / velocity / acceleration 平均速率/速度/加速度steady velocity 匀速 balanced 平衡的 stationary 静止的 combined effect 合成效应 resultant force 合力 moments and balance 力矩和平衡gravity / gravitational force 重力 centre of gravity 重心 gradient [’ɡreidj?nt]梯度arrow [‘?r?u] 箭头 horizontal [,h?ri’z?nt?l] 水平的 vertical [‘v?:tik?l] 垂直的it is more convenient to do something ......更方便+ plus [pl?s] 正号- minus[‘main?s] 负号increase/decrease + by 增加/减少了 increase/decrease + to 增加/减少到The newton is defined in this way:A 1 N resultant force gives a 1 kg mass an acceleration of 1 m s-2perpendicular [,p?:p?n’dikjul?] 垂直的符号:+ plus 加号;正号 - minus 减号;负号±plus or minus 正负号×is multiplied by 乘号÷is divided by 除号=is equal to 等于号≡is equivalent to 全等于号≠is not equal to 不等于号≈is approximately equal to 约等于号≌is equal to or approximately equal to 等于或约等于号<is less than 小于号>is more than 大于号≤is not less than 不小于号≥is not more than 不大于号≢is less than or equal to 小于或等于号≣is more than or equal to 大于或等于号% per cent 百分之…‰per mill 千分之…∞infinity 无限大号∝varies as 与…成比例√(square) root 平方根∵since; because 因为∴hence 所以∷equals, as (proportion) 等于,成比例∟angle 角≦circle 圆≨semicircle 半圆○circumference 圆周πpi 圆周率△ triangle 三角形≧perpendicular to 垂直于∠ horizontal to 平行于∪union of 并,合集∩intersection of 交,通集∫the integral of …的积分∑(sigma) summation of 总和°degree 度℃Celsius system 摄氏度′minute 分″ second 秒I seem to have been only like a boy playing on the seashore, and diverting myself in now and then finding asmoother pebble or a prettier shell than ordinary, whilst thegreat ocean of truth lay all undiscovered before me.我不过就象是一个在海滨玩耍的小孩,为不时发现比寻常更为光滑的一块卵石或比寻常更为美丽的一片贝壳而沾沾自喜,而对于展现在我面前的浩瀚的真理的海洋,却全然没有发现。
☆ If I can see a bit farther than some others, it is because I amstanding on the shoulders of giants.如果说我比别人看得更远些,那是因为我站在了巨人的肩膀上.resultant force 合力component force 分力uniform force 恒力resistance 阻力inertia 惯性 [i’n?:??] impulse 冲量action 作用 reaction 反作用 momentum 动量 conservation of momentum 动量守恒stationary / moving object 静止 / 运动的物体 constant velocity 恒定速度linked equation 相关方程initial velocity 初始速度 final velocity 末速度Newton’s first / second / third law 牛顿第一 / 二 / 三定律阻力推力摩擦力resistance thrust friction弹力重力elastic force gravity / weight斥力拉力repulsive force pulling / traction force∝与…成比 varies as / be proportional to 与…成反比 be inversely proportional toNewton’s second law of motion can be summarized in a simple vector equation:物体的加速度跟物体所受的合外力成正比,跟物体的质量成反比,加速度的方向跟合外力的方向相同。
A external force acting on an object produces an acceleration which is in the direction of the force and has a magnitude inversely proportional to the mass of the object.Jet engine: 喷气发动机Air is drawn in at the front by a large fan, and pushed out the back. Exhaust gases are also ejected, at a higher speed.一个大的鼓风机把空气从前面拉入,从后面推出。
尾气高速喷出。
Propeller: 螺旋桨This is driven by the shaft of a jet engine or piston engine. Its blades are angled so that air is pushed backwards as it rotates.shaft: 轴This is the shaft of a steam engine. 这是一个蒸汽机主轴。
这是由喷气发动机或活塞式发动机的轴驱动的。
当螺旋桨旋转时,它的叶片扭转,从而使空气从后面排出。
以弹簧为例,一个与弹簧相连、放在光滑轨道上的木块的运动就是简谐运动。
Take the spring as an example. A block attached to aspring on a frictionless track moves in simple harmonicmotion.According to the law of conservation of energy:Energy cannot be made or destroyed, but it can bechanged from one form to another.◎ Whenever there is an energy change, work is done –although this may not always be obvious. For example,when a car’s brakes are applied, the car slows down andthe barkes heat up, so kinetic energy is being changed intoElastic collision :the total kinetic energy of the colliding objects remainsconstant. In other words, no energy is converted intoheat (or other forms).☆ Inelastic collision :Kinetic energy is converted into heat. The total amountof energy is conserved, but the total amount of kineticenergy is not.temperature scale 温标 thermometer [θ?’m?mit?]温度计 thermometric property [,θ?:m?’metrik]测温特性 capillary tube [k?’pil?ri] 毛细管mercury [‘m?:kjuri] 汞,水银trapped 密封的 portable 可携带的fragile 易碎的 cumbersome[‘k?mb?s?m] 笨重的platinum [‘pl?tin?m] 铂thermistor 热敏电阻thermocouple 热电偶photodiode [,f?ut?u’dai?ud]光敏二极管0th law of thermodynamicsIf two objects are in thermal equilibrium with a third, then they are also in thermal equilibrium with each other.Liquid in glass 液体玻璃Constant-volume gas 定容气体Resistance temperature detectors (RTDs) 电阻温度探测器Thermistors 热敏电阻Thermocouple 热电偶Infrared Thermometry 红外测温heat capacity [k?’p?siti] 热容specific heat capacity 比热容molar heat capacity 摩尔热容specific latent heat 比潜热vaporization [,veip?rai’zei??n] 汽化fusion [‘fju:??n] 熔化condenser 冷凝器 heat engine 热机heat source 热源heat sink 冷源The first law of thermodynamicsThe increase in the internal energy of a system is equal to the amount of heat addedto the system, plus the amount of work done by the system.?ΔU = Q +WQ is positive when the system gains heat, and negative when the system loses heat.W is positive when it is done BY the system, and negative when it is done ON the system. second law of thermodynamics.No continually-working heat engine can take in heat and completely convert it intowork.A restatement of the Second Law which turns out to be equivalent:Heat will not flow from a colder body to a hotter body unless some other process (which does work) is also involved.Another restatement is:The entropy of an isolated system can only increase or remain constant. Its entropy cannot decrease.adiabatic expansion [,?di?’b?tik]绝热膨胀isothermal expansion 等温膨胀indicator diagram 示功图Brownian motion 布朗运动diffusion扩散 droplet 小滴electron hole droplet 电子空位液滴bombard [b?m’bɑ:d] 轰击An ideal gas is one which exactly obeys Boyle’s law. It can be shown that, for such a gas:The forces of attraction between the molecules are negligible.The molecules themselves have a negligible volume compared with the volume occupied by the gas.An ideal gas is an idealized model for real gases that have sufficiently low densities.1. Adaiabatic Expansionis one in which no heat is taken in or given out. There is a decrease in internal energy equal to the work done. As a result, the temperature of the gas falls.2. Isothermal Expansionis one in which no temperature is constant. There is no change in internal energy, so the gas takes in heat from it surroundings equal to the work done.Thermal conduction 热传导Thermal conductivity 热导率Rate of flow of heat 热流率Convection 对流Natural convection 自然对流Forced convection 强制对流Foam 泡沫材料 spinning 自旋的Black body 黑体Conduction is the transfer of thermal energy from a region of higher temperature to a region of lower temperature through direct molecular communication within a medium or between mediums in direct physical contact without a flow of the material medium. Thermal Conductivity 热导率Thermal conductivity is a material property that is primarily dependent on the medium's phase, temperature, density, and molecular bonding.Convection is a combination of conduction and the transfer of thermal energy by fluid circulation(环流) or movement of the hot particles in bulk to cooler areas in a material medium.1. Natural convectionIn natural convection a fluid surrounding a heat source receives heat, becomes less dense and rises.2. Forced convectionForced convection, by contrast, occurs when pumps, fans (通风机) or other means are used to propel ([pr?’pel]推动) the fluid and create an artificially induced convection current.Black body:A perfect absorber which reflects no radiation, and also the best possible emitterof thermal radiation.Vibrating and spinning molecules in one object give off electromagnetic radiationwhose energy can be absorbed by molecules in another object so that they speed up.This radiation is called thermal radiation.A very useful concept used in heat transfer applications is the representation ofthermal transfer by what is known as thermal circuits.1. Thermal insulators 热绝缘体2. Radiant barriers 辐射屏障3. Heat exchanger (热交换器)Static electricity 静电Polythene 聚乙烯Induced charge 感应电荷Current 电荷 ammeter 电流计 ampere 安培Semiconductor 半导体Permittivity offree space 真空中的介电常数Medium 介质 dielectric 电介质Relative permittivity相对介电常数 Equipotential line 等势线Capacitance 电容 capacitor电容器Magnet and field 磁和场Magnetic pole 磁极 magnetic field 磁场Maxwell’s screw rule 麦克斯韦螺旋法则Right-hand grip rule 右手螺旋法则electric motor 发电机 generatorcommutator 整流子 transformer 变压器step-up / down transformer 增压/ 减压变压electromagnetic induction 电磁感应direct current 直流电 alternatingcurrent 交流电Phasor 相量(相位变矢量)impedance 阻抗 [im?pi:d?ns]resistanceand reactance vectors 电阻和电抗矢量fuel-burning station 热电站distributionnetwork 配电网络overhead line 高架线 Grid 高压输电网pulse 脉冲 [p?ls] smoothing 滤波rectification 整流half-wave rectification 半波整流full-wave rectification全波整流If an induced current flows, its direction is always such that it will oppose thechange in flux which produced it.感应电流的方向趋于阻止产生此感应电流的磁通量的变化。