brass

Brass is an alloy of copper and zinc, in proportions which can be varied to achieve varying mechanical and electrical properties. It is a substitutional alloy: atoms of the two constituents may replace each other within the same crystal structure. 黄铜是铜和锌的合金，比例可以改变，以获得不同的机械和电气性能。这是一种替代合金：两种成分的原子可以在同一晶体结构内相互替换。

Brass is similar to bronze, another alloy containing copper that uses tin in place of zinc; both bronze and brass may include small proportions of a range of other elements including arsenic, lead, phosphorus, aluminum, manganese, and silicon. The distinction between the two alloys is largely historical, and modern practice in museums and archaeology increasingly avoids both terms for historical objects in favor of the more general "copper alloy". 黄铜与青铜相似，青铜是另一种含有铜的合金，用锡代替锌；青铜和黄铜都可能含有少量其他元素，包括砷、铅、磷、铝、锰和硅。这两种合金之间的区别在很大程度上是历史性的，博物馆和考古学的现代实践越来越多地避免使用这两个术语来描述历史物品，而倾向于使用更一般的“铜合金”。

Brass has long been a popular material for decoration for its bright gold-like appearance, e.g. for drawer pulls and doorknobs. It has also been widely used for all sorts of utensils due to many properties, such as low melting point, workability (both with hand tools and with modern turning and milling machines), durability, electrical and thermal conductivity. 黄铜一直以来都是一种流行的装饰材料，因为它有着明亮的金色外观，例如抽屉拉手和门把手。由于其许多特性，例如低熔点、可加工性（使用手动工具和现代车削和铣床）、耐久性、导电性和导热性，它也被广泛用于各种器皿。

It is still commonly used in applications where corrosion resistance and low friction is required, such as locks, hinges, gears, bearings, ammunition casings, zippers, plumbing, hose couplings, valves, and electrical plugs and sockets. It is used extensively for musical instruments such as horns and bells, and also used as substitute of copper in making costume jewelry, fashion jewelry and other imitation jewelry. The composition of brass, generally 66% copper and 34% zinc, makes it a favorable substitute for copper based jewelry as it exhibits greater resistance to corrosion. Brass is often used in situations in which it is important that sparks not be struck, such as in fittings and tools used near flammable or explosive materials. 它仍然常用于需要耐腐蚀和低摩擦的应用中，如锁、铰链、齿轮、轴承、弹药壳、拉链、管道、软管接头、阀门以及电气插头和插座。广泛用于制作喇叭、铃铛等乐器，也可代替铜制作服装首饰、时尚首饰等仿制首饰。黄铜的成分通常为66%的铜和34%的锌，这使它成为铜基珠宝的良好替代品，因为它具有更强的耐腐蚀性。黄铜通常用于不碰撞火花的情况，例如在易燃或易爆材料附近使用的配件和工具中。

A brass instrument is a musical instrument that produces sound by sympathetic vibration of air in a tubular resonator in sympathy with the vibration of the player's lips. Brass instruments are also called labrosones or labrophones, from Latin and Greek elements meaning 'lip' and 'sound'. 铜管乐器是一种乐器，它通过管状谐振器中空气的共振与演奏者嘴唇的振动产生声音。铜管乐器也被称为labrosones or labrophones，起源于拉丁语和希腊语，意思是“唇”和“音”。

the elements of sth = the most simple things that you have to learn first about a subject. 如She doesn't even know the basic elements of politeness.

The trumpet is a brass instrument commonly used in classical and jazz ensembles. The trumpet group ranges from the piccolo trumpet with the highest register in the brass family, to the bass trumpet, which is pitched one octave below the standard B♭ or C Trumpet. 小号是古典音乐和爵士乐合奏中常用的铜管乐器。小号组包括黄铜家族中音域最高的短笛小号和低音小号……

In Western music, the adjectives major and minor may describe an chord, scale [音阶], or key.

Like many musical scales, the major scale is made up of seven notes [音符]: the eighth duplicates the first at double its frequency so that it is called a higher octave [八度] of the same note (from Latin "octavus", the eighth). A natural minor scale is a diatonic scale [自然音阶] that is built by starting on the sixth degree of its relative major scale. For instance, the A natural minor scale can be built by starting on the 6th degree of the C major scale:

Because of this, the key of A minor is called the relative minor of C major. Every major key has a relative minor, which starts on the 6th scale degree or step. For instance, since the 6th degree of F major is D, the relative minor of F major is D minor. F1G2A3B4C5D6EFGAB... 似乎大调并不比小调大。

The simplest major scale to write is C major, the only major scale not requiring sharps [升半音] or flats [降半音]. B-flat major is a major scale based on B♭, with pitches B♭, C, D, E♭, F, G, and A. Its key signature has two flats.

Umm, 还是看频率表吧。:-) 似乎半音是最小单位。相邻半音之前的频率倍数是：2**(1/12) = 1.0594630943592953.  X major/minor的X指的是起始音。钢琴是最精密的乐器，因为它不仅有半音键，而且有很多键。玩具木琴只能奏出8个音。

类似地，显示器不是精准地、线性地显示颜色。有颜色空间、色域等概念。还有Gamma correction or gamma is a nonlinear operation used to encode and decode luminance or tristimulus values in video or still image systems. tristimulus = of or relating to values giving the amounts of the three colored lights red, green, and blue that when combined additively produce a match for the color being considered.

六级/考研单词: brass, alloy, copper, atom, constituent, crystal, bronze, tin, aluminum, silicon, melt, mill, durable, thermal, conduct, corrode, friction, hinge, gear, ammunition, plumbing, hose, valve, plug, socket, horn, substitute, costume, jewel, vogue, imitate, compose, exhibit, seldom, situate, spark, explode, sympathy, trumpet, classic, jazz, bass, adjective, chord, duplicate