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洗衣機 來看一下渦流式全自動洗衣機的構(gòu)造。這種洗衣機有各種各樣的型號，其基本構(gòu)造如圖4.4所示。 洗衣機之所以能兼具洗條和脫水的功能，是因為它有一個雙層水槽。在積滿水進行“洗條”和“漂洗”時，振動機旋轉(zhuǎn)，產(chǎn)生水流。脫水時，只有內(nèi)槽快速旋轉(zhuǎn)，將衣服中的水甩出。 最近漸漸流行的“離心式洗衣機”不是振動機旋轉(zhuǎn)，而是內(nèi)槽旋轉(zhuǎn)。當內(nèi)槽旋轉(zhuǎn)時，該作用力使衣服貼近內(nèi)層。由于水和洗條劑會從內(nèi)槽的空洞向外甩出，因此能快速從衣服中穿透，用這種沖擊力去除污后。這種機器的另一個好處是由于在水中衣物不會纏繞，因此不必擔心衣物扭曲,變形或壞掉。 下面看一看不同類型的洗衣機！ 也許很多人認為洗衣機中的水是在以同樣方式旋轉(zhuǎn)。事實上洗衣機的水流方式也有多種類型。 渦流式 這種類型洗衣機利用振動機的旋轉(zhuǎn)產(chǎn)生渦流，從而祛除污后。有的新型洗衣機能使渦流上下反復(fù)旋轉(zhuǎn)，從而使污后更容易祛除！ 攪拌式 這種洗衣機在底部有一個看起來像螺旋槳的帶有葉片的軸，它會反復(fù)地反方向轉(zhuǎn)動，將水攪動起來，然后水的作用力將衣物中的污后祛除。它具有使衣服不易纏繞，并能均勻清洗的優(yōu)點。 滾筒式 在開有許多小孔的圓筒中，有突出的板子。外圍的滾筒旋轉(zhuǎn)時，板子將衣物抬起，下落是時的沖力將污后祛除。 離心力式 就像我們前邊所說的那樣，旋轉(zhuǎn)的內(nèi)槽將水和洗條劑從內(nèi)槽壁推出。從內(nèi)槽向外甩出的力叫做“離心力”，這也是“離心力”這個名字的來源。這種洗衣機由于是內(nèi)槽旋轉(zhuǎn)，因此水會從內(nèi)槽猛地向外部噴射，然后又會回到內(nèi)槽中，不斷地循環(huán)往復(fù)。正是這種循環(huán)清潔了衣物！ 1930年，在日本，人們第一次開始使用洗衣機。不過，當時的售價還很高，并沒有普及到一般家庭。 在以前的洗衣機中，安裝了現(xiàn)在看起來有些可笑的部件。機器有兩根滾軸，夾住洗條衣物，把水擠出來。由于采用的是手動旋轉(zhuǎn)把手后滾軸轉(zhuǎn)動的構(gòu)造，所以需要相當大的力氣，不過在當時它還是非常便利，此后，這種滾軸式脫水機大約被使用了長達30年之久，一直到離心式脫水機出現(xiàn)為止。 1953年,渦流式洗衣機的原形分流式洗衣機在日本上市銷售。這種洗衣機就像現(xiàn)在所見的渦流式洗衣機的哥哥。由于這些洗衣機的價格低廉，使用洗衣機的家庭漸漸多起來。1968年，全自動式洗衣機登場，此后洗衣機變得愈加方便了。 洗衣機有許多種類。你們家里用的洗衣機屬于哪一種類型呢？ 全自動式 全自動式洗衣機通過雙層的水槽接連進行洗條，漂洗，脫水。你需要做的就是將洗條劑和衣物放入洗衣機，之后洗衣機會自動進行清洗。還有一種可以烘干衣物的新型的全自動洗衣機。 雙缸式 這種洗衣機進行洗條的部分與脫水的部分分離。雖然脫水時需要將衣物取出更換地方，但卻具有洗條與脫水能同時進行的好處。 滾筒式 滾筒式洗衣機的特點是用水量較少，洗衣店使用的多是滾筒式的。許多歐洲家庭中也使用這種類型的洗衣機。 讓我們制造出世界上最好的洗衣機！ 我們應(yīng)該很感激科學(xué)家發(fā)明出全自動洗衣機，因為它使洗衣服變成一件容易的事。 科學(xué)家仍在努力尋找方法使洗衣機的使用更加便利。另外，科學(xué)家們還正在努力，尋找更好的洗條衣物的方法和制造更耐用的洗衣機?，F(xiàn)在洗衣機具有烘干功能，所以你甚至洗后不用進行掛曬，因為它可以自動烘干衣物！太神奇了！ 目前科學(xué)家正在想方設(shè)法減少洗衣時的用水量。其原因是我們必須珍惜水資源，保護我們的環(huán)境。 你認為未來的洗衣機將會變成什么樣子呢？如果能有可以洗條，烘干，折疊衣物或是能在人穿著衣服時進行洗條的洗衣機的話，該有多方便??！記住。，如果第一臺洗衣機對舊時代的人們是一個夢想的話，那么對未來洗衣機的種種設(shè)想就很可能會變?yōu)楝F(xiàn)實。 讓我們想一想。為什么冰箱會制冷呢？如果先了解一下“汽化熱”這個詞的意思，就會明白它的秘密了。 打針的時候，護士會在注射前用含有酒精的棉球檫拭你的手腕處，這會使你的手腕處有冰涼的感覺。那是因為液態(tài)的酒精在轉(zhuǎn)變成氣體時（汽化過程）將手腕皮膚的熱量帶走的緣故。這種熱就叫做“汽化熱”。 在炎熱的夏天，往院子里灑上水就能變得涼快，也是因為汽化熱作用。水帶走了地面和空氣中的熱量，變成了水蒸氣。 冰箱制冷利用的就是這種汽化熱的交換作用。通過汽熱化將食品的熱量帶走，從而使它變冷，并將熱量排出。這就是冰箱的基本原理。汽化熱是怎樣產(chǎn)生的呢？ 冰箱的內(nèi)部構(gòu)造如圖4.5所示。 如果沿著單向的箭頭，就可以了解氣體是以怎樣的流向發(fā)生變化的?？拷鼔嚎s機的箭頭和其它的箭頭描述了氣體循環(huán)的情況。其各自的作用如下： 壓縮機：對氣體加壓，使它變?yōu)橐后w。 冷卻器：將熱量排到冰箱外部。 蒸發(fā)器：減壓，將液體還原為氣態(tài)。這時被帶走的汽化熱上冰箱冷卻。 那么，冰箱是如何進行汽化熱交換的呢？ 如仔細觀察冰箱后部，會發(fā)現(xiàn)許多上下環(huán)繞的管子。實際上，冰箱除了門以外的部分，都遍部有充入氣體的管子。這些管子里充滿氣體，當加壓時會變成液體，減壓時又會變成氣體。在從液體轉(zhuǎn)變?yōu)闅怏w的同時，發(fā)生帶走汽化熱的交換作用。冰箱反復(fù)地進行著這種交換流程。 直到20世紀90年代末，冷卻管內(nèi)才開始使用替代氟利昂。但是由于發(fā)現(xiàn)以前使用的“替代氟利昂”對地球環(huán)境不利，所以轉(zhuǎn)而使用其他氣體來代替。目前許多公司正在進一步開展“無氟冰箱”的制造，以更利于環(huán)境保護。 微波爐誕生于20世紀40年代末的美國。第二次世界大戰(zhàn)期間，微波技術(shù)廣泛應(yīng)用在雷達設(shè)備上，因此這一技術(shù)也得到了提高。戰(zhàn)后科學(xué)家們用這些知識發(fā)明了第一臺微波爐。事實上正式由于這一歷史原因，微波爐起初被叫做“雷達烤箱”。在那段時間，由于微波爐體積龐大，只有餐館和一些其他的行業(yè)使用。 20世紀60年代，日本制造出第一臺家用微波爐，但在當時只有富裕家庭才能買的起。而如今在許多國家人們都能買的起微波爐了。 有了微波爐，加熱剩飯菜會變的十分簡單。隨著人們越來越多的了解使用微波爐所帶來的便利，微波爐逐漸得到了推廣。接下來讓我們了解一下微波爐是如何發(fā)展的。 微波爐是使用一種被叫做微波的電磁波（所以稱微波爐）加熱食物的。這種微波類似海洋中的水波?？梢栽?秒鐘內(nèi)振動高達24億5千次。 大多數(shù)食物中都含有水分。當水分子在經(jīng)微波照射后會以非?？斓乃俣日駝印Ｒ虼藢⑽⒉ㄕ丈涞绞澄锷虾?，食物中的水分子會通過振動相互碰撞，相互摩擦。摩擦產(chǎn)生的熱叫摩擦熱，而它使食物變熱了。如果用火加熱食物，會從外避開始逐漸變熱，要加熱至內(nèi)部是需要一段時間的。而微波爐通過微波可以很快從食物內(nèi)部開始加熱。 讓我們來研究一下微波爐的內(nèi)部構(gòu)造，看到圖4.8中右上部的東西了嗎？它就是微波爐內(nèi)部被稱作“磁控管”的裝置。加熱食物所用的微波，就是在這里產(chǎn)生的。發(fā)出的微波，通過波導(dǎo)管送入內(nèi)部。 微波爐內(nèi)壁由金屬制成。這是因為如果微波第一次沒有照到食物上，與內(nèi)壁碰撞之后也會被彈回照到食物上。在門上覆蓋有隔板，這樣微波就不會泄漏到外部。 位于微波爐正中央的是轉(zhuǎn)盤。是否注意到在用微波爐加熱時，轉(zhuǎn)盤總是會不停的旋轉(zhuǎn)？ 微波通過波導(dǎo)管送入微波爐內(nèi)部時，不管怎樣總會有一些地方照到微波，而有些地方很難照到，產(chǎn)生出差異來。這樣一來，即使對食物進行加熱，也會使得有些地方熱，有些地方?jīng)觥＿@樣食物就不好吃了。 怎樣才能將微波均勻地照射到食物上呢？科學(xué)家反復(fù)研究后發(fā)現(xiàn)，通過轉(zhuǎn)動食物要比試圖改變微波以使其均勻照射更容易解決這一問題。于是就制作了轉(zhuǎn)盤，將食物擺在上面旋轉(zhuǎn)。 看到過雪的結(jié)晶嗎？將雪抓到受中時，有時可瞬間地看到它的形狀，雪晶體呈現(xiàn)以六角形為基礎(chǔ)。比如雪融化成水時就不在是結(jié)晶狀態(tài)了。 大家知道物體有固態(tài)、液態(tài)、氣態(tài)三種狀態(tài)吧？大多數(shù)物體都只有這三種狀態(tài)。但是某些物體在轉(zhuǎn)化過程中還保持一種介于固態(tài)和液態(tài)之間的一種狀態(tài)。在這種情況下，這種物體雖然以液體的形式存在，但仍然保留著規(guī)則有序的結(jié)晶狀排列。 從很久以前，人們就了解了這一現(xiàn)象。這一現(xiàn)象得到廣泛確認后，從1889年在德國發(fā)表了叫做“流動晶體”的研究報告，距今已經(jīng)100多年了。經(jīng)過長時間的研究和發(fā)表，液晶電視達到了目前的水平。 將釘子放在兩塊磁鐵之間，釘子的兩端會向兩塊磁鐵的方向靠近。與此相同，液晶并非成圓形，而是成細長形狀，通電時具有與電流方向平行排列的性質(zhì)。 在液晶電視機的屏幕中，兩片玻璃之間有許多很小的間隔，分別在里面注入液晶，有紅、藍、綠三種顏色。由于平時液晶都在非活躍狀態(tài)，所以即使有光線從屏幕后面照射過來也不會透光。 然而，當電流在藍色間隔通過時，這個間隔中的液晶活躍起來，并透過光線。這就是畫面怎樣變成藍色的緣故。混合紅、藍、綠（光的三原色）光后產(chǎn)生出各種顏色，這一點與顯像管電視機相同，不過是液晶的光通過關(guān)閉或者特過光線而產(chǎn)生不同的顏色。 兩片玻璃的間距僅為千分之五毫米。其空間只是頭發(fā)的千分之一左右。在那里面裝入液晶并讓它按我們的要求運動是很了不起的，而要把兩片玻璃在如此小的空間中毫不彎曲地支撐起來就更了不起了。所以把液晶電視做成30英寸那么小是很難的。 由于這種技術(shù)基于開閉或打開光閥決定是否透光，因此生產(chǎn)液晶電視還存在一個難點，也就是從莫一角度看，屏幕會很暗，但人們找到了解決這些問題的方法，曾被認為不可能的液晶電視機也制造出來了。不知道當你成為大人的時候，什么樣的液晶電視會存在你周圍。 外文翻譯資料 washing machines 洗衣機 Let’s look inside one of today’s fully automatic washing machines that use swirling water to clean the clothes. There are many types of washing machines but this Fig.4.4 shows you what most of them are basically made up of. 來看一下渦流式全自動洗衣機的構(gòu)造。這種洗衣機有各種各樣的型號，其基本構(gòu)造如圖4.4所示。 The reason why a washing machine like this can wash and get the water out of the clothes at the same time is because it has a double layer drum. When washing and rinsing, the pulsator spins and makes the water swirl.. To get the water out of the clothes, the inner wall f the drum spins and the water goes through the holes. 洗衣機之所以能兼具洗條和脫水的功能，是因為它有一個雙層水槽。在積滿水進行“洗條”和“漂洗”時，振動機旋轉(zhuǎn)，產(chǎn)生水流。脫水時，只有內(nèi)槽快速旋轉(zhuǎn)，將衣服中的水甩出。 These days, the “centrifugal force washing machines” are quite popular. This type of machine does not use a pulsator. Instead, the inner wall spins really quickly. When the drum spins, the dirty clothes get stuck to the wall. The water and detergent also try to escape through the holes of the wall but before they do so, they are forced to escape through the clothes. When this happens, the power of the water and detergent removes the dirt form the clothes. Another good thing about this type of machine is that clothes don’t get tangled up so you don’t have to worry about your clothes getting ripped or damaged. 最近漸漸流行的“離心式洗衣機”不是振動機旋轉(zhuǎn)，而是內(nèi)槽旋轉(zhuǎn)。當內(nèi)槽旋轉(zhuǎn)時，該作用力使衣服貼近內(nèi)層。由于水和洗條劑會從內(nèi)槽的空洞向外甩出，因此能快速從衣服中穿透，用這種沖擊力去除污后。這種機器的另一個好處是由于在水中衣物不會纏繞，因此不必擔心衣物扭曲,變形或壞掉。 Next, let’s look at some different types of washing machines! 下面看一看不同類型的洗衣機！ Many of you probably think that the water inside washing machines goes round and round. Actually, different washing machines make water flow in different ways. 也許很多人認為洗衣機中的水是在以同樣方式旋轉(zhuǎn)。事實上洗衣機的水流方式也有多種類型。 Whirlpool type 渦流式 This type of washing machine uses a pulsator to force the water to move like a whirlpool inside the Drum. The spinning water forces the dirt out form the clothes inside the machine. Some of the newer models of this type also make the whirlpool move up and down to make it clean clothes even better! 這種類型洗衣機利用振動機的旋轉(zhuǎn)產(chǎn)生渦流，從而祛除污后。有的新型洗衣機能使渦流上下反復(fù)旋轉(zhuǎn)，從而使污后更容易祛除！ Agitator stirring type 攪拌式 This type of washing machine has something that looks like a propeller at the bottom of the tub. This Propeller spins around and stirs the water. The water then forces the dirt out from the clothes in the machine. The good thing about this type of machine is that clothes do not get tangled up and clothes get evenly washed. 這種洗衣機在底部有一個看起來像螺旋槳的帶有葉片的軸，它會反復(fù)地反方向轉(zhuǎn)動，將水攪動起來，然后水的作用力將衣物中的污后祛除。它具有使衣服不易纏繞，并能均勻清洗的優(yōu)點。 Drum type 滾筒式 This type of machine has a drum with many holes in it. There are also protrusions bumps on the wall of the drum. As the drum turns, the clothes are picked up by the protrusions. When the clothes fall down from the top of the drum through the water, the movement removes dirt from the clothes. 在開有許多小孔的圓筒中，有突出的板子。外圍的滾筒旋轉(zhuǎn)時，板子將衣物抬起，下落是時的沖力將污后祛除。 Centrifugal force type 離心力式 As we have said before, the spinning drum pushes the water and detergent out through the wall of the inner drum. The power that comes form spinning the drum is called centrifugal force., which is where the name comes from. The water is forced through the clothes and then the holes in the inner wall. After one cycle, the water is recycled back into the tank and the process starts again. This cycle is what cleans the clothes! 就像我們前邊所說的那樣，旋轉(zhuǎn)的內(nèi)槽將水和洗條劑從內(nèi)槽壁推出。從內(nèi)槽向外甩出的力叫做“離心力”，這也是“離心力”這個名字的來源。這種洗衣機由于是內(nèi)槽旋轉(zhuǎn)，因此水會從內(nèi)槽猛地向外部噴射，然后又會回到內(nèi)槽中，不斷地循環(huán)往復(fù)。正是這種循環(huán)清潔了衣物！ In Japan, people first started using machines in 1930. But then the price of a washing machine was so high that most average persons could not buy one for their homes. 1930年，在日本，人們第一次開始使用洗衣機。不過，當時的售價還很高，并沒有普及到一般家庭。 Looking back now, there was something strange and funny on some of the first versions of the washing machine .The machine had two rollers that were used to sandwich each shirt and other clothes to squeeze the water out of them. The rollers were turned by hand, and in fact, you needed a lot of strength to turn those things! Still, people then thought it was a really neat invention! This type of water squeezer was used for almost 30 years until something new came along. The spin drier that used “centrifugal force” to get most of the water out of the clothes. 在以前的洗衣機中，安裝了現(xiàn)在看起來有些可笑的部件。機器有兩根滾軸，夾住洗條衣物，把水擠出來。由于采用的是手動旋轉(zhuǎn)把手后滾軸轉(zhuǎn)動的構(gòu)造，所以需要相當大的力氣，不過在當時它還是非常便利，此后，這種滾軸式脫水機大約被使用了長達30年之久，一直到離心式脫水機出現(xiàn)為止。 In 1953, the nozzle type washing machine was first sold in Japan. This washing machine is like the older brother of the swirling washing machine that you see today. The price of these washing machines was lower and because of this, more people bought them. The first fully automatic washing machine was introduced in 1968, and after that, washing clothes became a lot easier to do! 1953年,渦流式洗衣機的原形分流式洗衣機在日本上市銷售。這種洗衣機就像現(xiàn)在所見的渦流式洗衣機的哥哥。由于這些洗衣機的價格低廉，使用洗衣機的家庭漸漸多起來。1968年，全自動式洗衣機登場，此后洗衣機變得愈加方便了。 There are a lot of different types of washing machines. What kind of washing machine do you have in your house? 洗衣機有許多種類。你們家里用的洗衣機屬于哪一種類型呢？ Fully automatic: 自動式 The fully automatic machine has two drum layers that wash, rinse and remove water from clothes together. All you have to do is add detergent and put in dirty clothes and then washing machine will do the rest. There is also a new type of fully automatic washing machine that can dry clothes after they have been washed. 全自動式洗衣機通過雙層的水槽接連進行洗條，漂洗，脫水。你需要做的就是將洗條劑和衣物放入洗衣機，之后洗衣機會自動進行清洗。還有一種可以烘干衣物的新型的全自動洗衣機。 Twin tub: 雙缸式 This washing machine has one part that dose the washing and another part that does the squeezing. Even though it’s a hassle to take the clothes out and move them to other tub, the good thing is that you can wash and squeeze at the same time with one machine. 這種洗衣機進行洗條的部分與脫水的部分分離。雖然脫水時需要將衣物取出更換地方，但卻具有洗條與脫水能同時進行的好處。 Front loading: 滾筒式 The main feature of front loaders is that they use a lot less water than other types. This is the type of Washing machine that dry cleaners use but a lot of people in western countries have this type of washing machine in their homes too. 滾筒式洗衣機的特點是用水量較少，洗衣店使用的多是滾筒式的。許多歐洲家庭中也使用這種類型的洗衣機。 Let’s try to make the best washing machine in the world! 讓我們制造出世界上最好的洗衣機！ We should already thank the scientists that invented the fully automatic washing machine because it makes washing clothes a piece of cake. 我們應(yīng)該很感激科學(xué)家發(fā)明出全自動洗衣機，因為它使洗衣服變成一件容易的事。 Scientists are still trying really hard to find ways to make washing machines a lot handier to use for everyone. Some of the things that they are trying to do are to find better ways of making clothes clean and ways to make washing machines last longer. There are washing machines with d trying function today so you don’t even have to hang clothes after words because it dries them automatically! Amazing! 科學(xué)家仍在努力尋找方法使洗衣機的使用更加便利。另外，科學(xué)家們還正在努力，尋找更好的洗條衣物的方法和制造更耐用的洗衣機。現(xiàn)在洗衣機具有烘干功能，所以你甚至洗后不用進行掛曬，因為它可以自動烘干衣物！太神奇了！ Scientists are also trying to find ways to use less water and less detergent in washing machines at present. This is because that it is better to use less water for preserving the environment. 目前科學(xué)家正在想方設(shè)法減少洗衣時的用水量。其原因是我們必須珍惜水資源，保護我們的環(huán)境。 What are washing machines of the future going to be like? Maybe there will be a washing machine that dries and folds your clothes after washing them, or maybe there will be one that will wash your clothes while you are still wearing them! How handy would that be! Remember, if the first washing machine was like a dream to people in the old days, all the dreams you have about washing machines of the future may come true! 你認為未來的洗衣機將會變成什么樣子呢？如果能有可以洗條，烘干，折疊衣物或是能在人穿著衣服時進行洗條的洗衣機的話，該有多方便啊！記住。，如果第一臺洗衣機對舊時代的人們是一個夢想的話，那么對未來洗衣機的種種設(shè)想就很可能會變?yōu)楝F(xiàn)實。 Now, Let’s try to figure out why refrigerators get cold. First, we should find out what vaporization heat is. One we know this, the rest is easy! 讓我們想一想。為什么冰箱會制冷呢？如果先了解一下“汽化熱”這個詞的意思，就會明白它的秘密了。 When you go to the doctors to get your shots (injections), the nurse usually wipes alcohol on your arm with a cotton ball before she puts the needle into your arm. When she does that, that part of your arm feels really cool. The reason why it feels coll is that when liquid alcohol turns into vapor (a prcess called vaporization), it steals the heat away from the skin on that part of your arm. The heat leaving your skin is called vaporization heat. 打針的時候，護士會在注射前用含有酒精的棉球檫拭你的手腕處，這會使你的手腕處有冰涼的感覺。那是因為液態(tài)的酒精在轉(zhuǎn)變成氣體時（汽化過程）將手腕皮膚的熱量帶走的緣故。這種熱就叫做“汽化熱”。 The reason why sprinkling water on your yard on a really hot summer day makes you feel cool is because of vaporization heat. The sprinkled water steals the heat away from the ground and air and turns into vapor. 在炎熱的夏天，往院子里灑上水就能變得涼快，也是因為汽化熱作用。水帶走了地面和空氣中的熱量，變成了水蒸氣。 Refrigerators also exchange vaporization heat to become cool. The main way a refrigerator cools down is using vaporization heat to steal heat away from food and then taking it outside. How do you make (or induce) vaporization heat? 冰箱制冷利用的就是這種汽化熱的交換作用。通過汽熱化將食品的熱量帶走，從而使它變冷，并將熱量排出。這就是冰箱的基本原理。汽化熱是怎樣產(chǎn)生的呢？ The inside of the walls of a refrigerator looks like Fig.4.5. 冰箱的內(nèi)部構(gòu)造如圖4.5所示。 You will be able to figure out how he gas flows and where it changes from gas to liquid if you follow the single arrows (in the Fig.4.5). The arrow near the compressor and other arrows are what are used to move the gas around arrows means. 如果沿著單向的箭頭，就可以了解氣體是以怎樣的流向發(fā)生變化的?？拷鼔嚎s機的箭頭和其它的箭頭描述了氣體循環(huán)的情況。其各自的作用如下： Compressor: Squeezes the gas and turns it into liquid. 壓縮機：對氣體加壓，使它變?yōu)橐后w。 Condenser: Takes the heat away from the refrigerator. 冷卻器：將熱量排到冰箱外部。 Evaporator: Takes the pressure away to turn liquid back into gas. The vaporization heat taken heat taken away at this point is what cools the refrigerator. 蒸發(fā)器：減壓，將液體還原為氣態(tài)。這時被帶走的汽化熱上冰箱冷卻。 Now let’s try to figure out how refrigerators exchange vaporization heat. 那么，冰箱是如何進行汽化熱交換的呢？ If you look closely at the back of a refrigerator, you will find a lot of tubes that go up and down. These tubes are attached to every wall, except the door of course. These tubes have gas in them and when the gas is squeezed (or compressed), it turns into liquid. When it is released, the liquid turns into gas again. When the gas changes from liquid back to gas again, vaporization heat is removed from the inside of the refrigerator. This process is repeated over and over all day long. 如仔細觀察冰箱后部，會發(fā)現(xiàn)許多上下環(huán)繞的管子。實際上，冰箱除了門以外的部分，都遍部有充入氣體的管子。這些管子里充滿氣體，當加壓時會變成液體，減壓時又會變成氣體。在從液體轉(zhuǎn)變?yōu)闅怏w的同時，發(fā)生帶走汽化熱的交換作用。冰箱反復(fù)地進行著這種交換流程。 Until the late 1990’s, chlorofluoro methane carbon (CFC) gas was used inside the tubes. But scientists found out that CFCs were actually bad for the environment and nowadays, a different gas is being used more and more instead. Many companies are now trying to make refrigerators that are CFC free so that they are better for the environment. 直到20世紀90年代末，冷卻管內(nèi)才開始使用替代氟利昂。但是由于發(fā)現(xiàn)以前使用的“替代氟利昂”對地球環(huán)境不利，所以轉(zhuǎn)而使用其他氣體來代替。目前許多公司正在進一步開展“無氟冰箱”的制造，以更利于環(huán)境保護。 The microwave oven was invented in the late 1940s in the US. During World War II, microwave.Technology was used a lot in radar equipment, so the technology was advanced. After the war, scientists Used the knowledge that they had of microwaves to invent the first microwave oven. In fact, the microwave oven was called a “radar oven” at first because of its history. Back then, microwave ovens were so big that only restaurants and other businesses used them. 微波爐誕生于20世紀40年代末的美國。第二次世界大戰(zhàn)期間，微波技術(shù)廣泛應(yīng)用在雷達設(shè)備上，因此這一技術(shù)也得到了提高。戰(zhàn)后科學(xué)家們用這些知識發(fā)明了第一臺微波爐。事實上正式由于這一歷史原因，微波爐起初被叫做“雷達烤箱”。在那段時間，由于微波爐體積龐大，只有餐館和一些其他的行業(yè)使用。 In the 1960s, the first home-use microwave oven was made in Japan. In those days, only rich people could afford it, but now a day , microwave ovens are more affordable for people in many countries. 20世紀60年代，日本制造出第一臺家用微波爐，但在當時只有富裕家庭才能買的起。而如今在許多國家人們都能買的起微波爐了。 It is easy to heat up yesterday’s leftovers with a microwave oven. As people like you start to understand more about how easy and convenient microwave ovens are, their popularity grow. Next, let’s look at how microwave ovens have changed over time. 有了微波爐，加熱剩飯菜會變的十分簡單。隨著人們越來越多的了解使用微波爐所帶來的便利，微波爐逐漸得到了推廣。接下來讓我們了解一下微波爐是如何發(fā)展的。 Microwave ovens heat up food using electromagnetic waves called microwave (hence the name). These microwaves oscillate (go up and down like a wave in the ocean) 2,400,005,000(2.4 billion) times every second! 微波爐是使用一種被叫做微波的電磁波（所以稱微波爐）加熱食物的。這種微波類似海洋中的水波?？梢栽?秒鐘內(nèi)振動高達24億5千次。 Most food contains water. When microwaves hit molecules of water, the molecules start vibrating really fast, which makes the water molecules hit each other and rub against each other. Heat caused by rubbing is called “frictional heat and this what starts cooking the food. If you use fire to heat something, it starts to get hot from the outside and it takes some time before the inside gets hot. But because microwave ovens use the power of microwaves, they can start cooking food from the inside right away. 大多數(shù)食物中都含有水分。當水分子在經(jīng)微波照射后會以非常快的速度振動。因此將微波照射到食物上后，食物中的水分子會通過振動相互碰撞，相互摩擦。摩擦產(chǎn)生的熱叫摩擦熱，而它使食物變熱了。如果用火加熱食物，會從外避開始逐漸變熱，要加熱至內(nèi)部是需要一段時間的。而微波爐通過微波可以很快從食物內(nèi)部開始加熱。 Let’s take a look inside a microwave oven. Do you see that thing at the top right of the Fig.4.8? That is what is called a magnetron. This device makes the microwaves that heat and cook your food. The microwaves enter the oven area by traveling through a tube called a wave -guide. 讓我們來研究一下微波爐的內(nèi)部構(gòu)造，看到圖4.8中右上部的東西了嗎？它就是微波爐內(nèi)部被稱作“磁控管”的裝置。加熱食物所用的微波，就是在這里產(chǎn)生的。發(fā)出的微波，通過波導(dǎo)管送入內(nèi)部。 The inner wall is made of metal wall hit your food, even if they miss it the first time. The microwave door has a special oven on it that stops microwaves from escaping outside. 微波爐內(nèi)壁由金屬制成。這是因為如果微波第一次沒有照到食物上，與內(nèi)壁碰撞之后也會被彈回照到食物上。在門上覆蓋有隔板，這樣微波就不會泄漏到外部。 In the middle of the microwave oven is the turntable. Do you notice that when you heat something in a microwave oven, the turntable is always turning? 位于微波爐正中央的是轉(zhuǎn)盤。是否注意到在用微波爐加熱時，轉(zhuǎn)盤總是會不停的旋轉(zhuǎn)？ When the wave-guide tube we talked about before injects microwaves into the inside of a microwave oven, there are always some areas that get hit with a lot of waves and some areas that don’t. If food was warmed up like that, there would be parts that were hot and parts that were cold, so the food wouldn’t taste too good. 微波通過波導(dǎo)管送入微波爐內(nèi)部時，不管怎樣總會有一些地方照到微波，而有些地方很難照到，產(chǎn)生出差異來。這樣一來，即使對食物進行加熱，也會使得有些地方熱，有些地方?jīng)觥＿@樣食物就不好吃了。 How do you get the microwaves to hit all parts of the food evenly? Scientists mulled over this question for a very long time and realized that moving the food was a lot easier than trying to make the microwaves reach every corner of the oven evenly. That’s why scientists started using turntables to spin the food inside microwave ovens. 怎樣才能將微波均勻地照射到食物上呢？科學(xué)家反復(fù)研究后發(fā)現(xiàn)，通過轉(zhuǎn)動食物要比試圖改變微波以使其均勻照射更容易解決這一問題。于是就制作了轉(zhuǎn)盤，將食物擺在上面旋轉(zhuǎn)。 Have you ever seen a snow crystal? Sometimes it’s possible to see them for a short moment when snow lands on your hand, but most of the time it melts before you get to see the beautiful hexagon-shaped (six said) crystals. Crystals are made up of particles that are arranged in a regular its crystal shape. 看到過雪的結(jié)晶嗎？將雪抓到受中時，有時可瞬間地看到它的形狀，雪晶體呈現(xiàn)以六角形為基礎(chǔ)。比如雪融化成水時就不在是結(jié)晶狀態(tài)了。 Do you know that there are three states for most objects: solid, liquid and gas? Most things only come in these three forms. However, some material can remain in a state that is somewhat between a solid and a liquid, In this state, the object is a liquid but still maintains the regular crystal like arrangement. 大家知道物體有固態(tài)、液態(tài)、氣態(tài)三種狀態(tài)吧？大多數(shù)物體都只有這三種狀態(tài)。但是某些物體在轉(zhuǎn)化過程中還保持一種介于固態(tài)和液態(tài)之間的一種狀態(tài)。在這種情況下，這種物體雖然以液體的形式存在，但仍然保留著規(guī)則有序的結(jié)晶狀排列。 The existence of this state has been known for a very long time. In fact, there was a research article titled “the flowing crystal “ that was published in 1889, over 100 years ago. It took many, many years of research and development to get liquid-crystal display TVs to the point that they are at now. 從很久以前，人們就了解了這一現(xiàn)象。這一現(xiàn)象得到廣泛確認后，從1889年在德國發(fā)表了叫做“流動晶體”的研究報告，距今已經(jīng)100多年了。經(jīng)過長時間的研究和發(fā)表，液晶電視達到了目前的水平。 If you put a nail in the middle of two magnets, the ends of the nail try to point towards each magnet. Similarly, crystals do not have a round shape but have a long narrow shape and when electricity is passed through a crystal, it tries to align itself in the direction of the electrical flow. 將釘子放在兩塊磁鐵之間，釘子的兩端會向兩塊磁鐵的方向靠近。與此相同，液晶并非成圓形，而是成細長形狀，通電時具有與電流方向平行排列的性質(zhì)。 In a Liquid crystal TV, many small compartments are left between two pieces of glass. Each of these Compartments holds liquid crystals that are colored red, blue or green. Even if light is shined on the back of the screen, the screen remains black because the liquid crystals are not active and block any light from passing through it. 在液晶電視機的屏幕中，兩片玻璃之間有許多很小的間隔，分別在里面注入液晶，有紅、藍、綠三種顏色。由于平時液晶都在非活躍狀態(tài)，所以即使有光線從屏幕后面照射過來也不會透光。 However, when electricity passes through a blue compartment, the liquid crystal in that compartment become active and allowed light through. That’s how a screen becomes blue. The way different colors are made by combining the three primary colors of light (red, blue and green) is the same as the cathode ray tube TV, but in this case, the shutters of the liquid crystals block or let light pass and that’s how different colors are made. 然而，當電流在藍色間隔通過時，這個間隔中的液晶活躍起來，并透過光線。這就是畫面怎樣變成藍色的緣故?；旌霞t、藍、綠（光的三原色）光后產(chǎn)生出各種顏色，這一點與顯像管電視機相同，不過是液晶的光通過關(guān)閉或者特過光線而產(chǎn)生不同的顏色。 The space between the two sheets of glass that we talked about is only 5/1000th of a millimeter. That is 1/10th the thickness of a piece of hair. It’s amazing that people have invented a way to control the movement of liquid crystals in such a small space. What’s more amazing is that people have developed a way to support these two pieces of glass between such a small space without letting it bend or sag. In fact, making a 30’ TV of this size is a very, very different task. 兩片玻璃的間距僅為千分之五毫米。其空間只是頭發(fā)的千分之一左右。在那里面裝入液晶并讓它按我們的要求運動是很了不起的，而要把兩片玻璃在如此小的空間中毫不彎曲地支撐起來就更了不起了。所以把液晶電視做成30英寸那么小是很難的。 An nother different part of the liquid crystal TV is that the screen looks dark from an angle because the technology is based on a shutter closing or opening to allow light through. Yet, people have found a way to solve these difficulties and made liquid-crystal TVs that some said could never be made. You never know what kind what kind of liquid of liquid crystal TVs will be around when you become an adult. 由于這種技術(shù)基于開閉或打開光閥決定是否透光，因此生產(chǎn)液晶電視還存在一個難點，也就是從莫一角度看，屏幕會很暗，但人們找到了解決這些問題的方法，曾被認為不可能的液晶電視機也制造出來了。不知道當你成為大人的時候，什么樣的液晶電視會存在你周圍。 11