逐句精讲新概念英语第二册:第72课“蓝鸟”汽车
Lesson 72: A car called bluebird
新概念英语2课文内容：
The great racing driver, Sir Malcolm Campbell, was the first man
to drive at over 300 miles per hour. He set up a new world record in September 1935 at Bonneville Salt Flats, Utah. Bluebird, the car he was driving, had been specially built for him. It was over 30 feet in length and had a 2,500-horsepower engine. Although Campbell reached a speed of over 304 miles per hour, he had great difficulty in controlling the car because a tyre burst during the first run. After his attempt, Campbell was disappointed to learn that his average speed had been 299 miles per hour. However, a few days later, he was told that a mistake had been made. His average speed had been 301 miles per hour. Since that time, racing drivers have reached speeds over 600 miles an hour. Following in his father's footsteps many
years later, Sir Malcolm's son, Donald, also set up a world record. Like his father, he was driving a car called Bluebird.
新概念英语2句子讲解：
1、The great racing driver, Sir Malcolm Campbell, was the first man to drive at over 300 miles per hour.
杰出的赛车选手马尔科姆?坎贝尔爵士是第一个以每小时超过300英里妁速度驾车的人。
语言点 sb. be the first to do sth.某人成为第一个去做某事的人：Zhang Jian was the first Chinese to swim across the English Channel.
张健是第一个成功游过英吉利海峡的中国人。
2、He set up a new world record in September 1935 at Bonneville Salt Flats, Utah.
他于1935年9月在犹他州的邦纳维尔盐滩创造了一项新的世界纪录。
语言点 set up a new world record创造一项新的世界纪录(见Lesson 36)
3、Bluebird, the car he was driving, had been specially built for him.
他驾驶的“蓝鸟”牌汽车是专门为他制造的。
4、It was over 30 feet in length and had a 2,500-horsepower engine.
它的车身长30多英尺，装有一个2500马力的发动机。
5、Although Campbell reached a speed of over 304 miles per hour, he had great difficulty in controlling the car because a tyre burst during the first run.
尽管坎贝尔达到了每小时超过304英里的速度，但他很难把汽车控制住，
因为在开始的行程中爆了一只轮胎。
语言点“reach a speed of +数字” =“go at a speed of +数字”，表
本“达到……速度”。
6、After his attempt, Campbell was disappointed to learn that his average speed had been 299 miles per hour.
比赛结束后，坎贝尔非常失望地得知他的平均时速是299英里。
7、However, a few days later, he was told that a mistake had been made.
然而，几天之后,有人告诉他说弄错了。
8、His average speed had been 301 miles per hour.
他的平均时速实际上是301英里。
9、Since that time, racing drivers have reached speeds of over 600 miles an hour.
自那时以来，赛车选手已达到每小时600英里的速度。
10、Following in his father’s footsteps many years later, Sir Malcolm’s son，Donald, also set up a world record.
多年以后，马尔科姆爵士的儿子唐纳德踏着父亲的足迹，也创造一项世界纪录。
语言点 follow sb’s footsteps追寻/沿着某人的足迹。
11、Like his father, he was driving a car called Bluebird.
同他父亲一样，他也驾驶着一辆名叫“蓝鸟”的汽车。
真空泵是用各种方法在某一封闭空间中产生、改善和维持真空的装置。真空泵可以定义为：利用机械、物理、化学或物理化学的方法对被抽容器进行抽气而获得真空的器件或设备。随着真空应用的发展，真空泵的种类已发展了很多种，其抽速从每秒零点几升到每秒几十万、数百万升。极限压力(极限真空)从粗真空到10-12Pa以上的超高真空范围。 由于真空应用部门所涉及的工作压力的范围很宽，因此任何一种类型的真空泵都不可能完全适用于所有的工作压力范围，只能根据不同的工作压力范围和不同的工作要求，使用不同类型的真空泵。为了使用方便和各种真空工艺过程的需要，有时将各种真空泵按其性能要求组合起来，以机组型式应用。 凡是利用机械运动(转动或滑动)以获得真空的泵，称为机械真空泵。机械真空泵按其工作原理及结构特点分述如下： 1、变容真空泵 它是利用泵腔容积的周期变化来完成吸气和排气以达到抽气目的的真空泵。气体在排出泵腔前被压缩。这种泵分为往复式及旋转式两种。 (1)往复式真空泵 利用泵腔内活塞往复运动，将气体吸入、压缩并排出。又称为活塞式真空泵。 (2)旋转式真空泵 利用泵腔内转子部件的旋转运动将气体吸入、压缩并排出。它大致有如下几种分类： a、油封式真空泵 它是利用真空泵油密封泵内各运动部件之间的间隙，减少泵内有害空间的一种旋转变容真空泵。这种泵通常带有气镇装置。它主要包括旋片式真空泵、定片式真空泵、滑阀式真空泵、余摆线真空泵等。 b、液环真空泵 将带有多叶片的转子偏心装在泵壳内。当它旋转时，把工作液体抛向泵壳形成与泵壳同心的液环，液环同转子叶片形成了容积周期变化的几个小的旋转变容吸排气腔。工作液体通常为水或油，所以亦称为水环式真空泵或油环式真空泵。 c、干式真空泵 它是一种泵内不用油类(或液体)密封的变容真空泵。由于干式真空泵泵腔内不需要工作液体，因此，适用于半导体行业、化学工业、制药工业及食品行业等需要无油清洁真空环境的工艺场合。 d、罗茨真空泵 泵内装有两个相反方向同步旋转的双叶形或多叶形的转子。转子间、转子同泵壳内壁之间均保持一定的间隙。 2、动量传输泵 它依靠高速旋转的叶片或高速射流，把动量传输给气体或气体分子，使气体连续不断地从泵的入口传输到出口。这类泵可分为以下几种形式： (1)分子真空泵 它是利用高速旋转的转子把动量传输给气体分子，使之获得定向速度，从而被压缩、被驱向排气口后为前级抽走的一种真空泵。这种泵具体可分为： a、牵引分子泵
新概念英语第二册第71、72课词组all over the world全世界(美国人有时用the world over) B．B．C．＝British Broadcasting Corporation英国广播公司 the Houses of Parliament英国议会两院 burn down烧毁 takes (its) name from取(其)名于 be responsible for负责办…… be of immense size体积很大 这种带of的句子，用作表语，有“很”之意 例：…is of great importance 很重要 …is of little significance．很不重要 be connected to与……相连结 go wrong出毛病 fail to不能 give (the correct) time报(准)时． slow down使慢下来，减速 twice a day每日二次 习题部分词组 now that既然 went on strike罢工 work as充当 the washing洗的衣服 work on搞了，干了 capital punishment极刑 第72 课 sett up a record创记录 reached a speed of /reached speeds of 达到……之速度 have difficulty in 在……方面有难处 be disappointed to learn在得悉……感到很不满意(扫兴) 习题部分词组 dress up as扮成 specially特意 we came specially to learn how to raise rice seedlings．(育秧) stories specially written for children． I came here specially to see you． especially尤其，格外 WaShingron is beautiful，especially in late Autumn． No profession，as a profession，is especially noble or ignoble．(作为一种职业来说，没有什么职业是格外的高贵或格外的低贱。It has been especially cold this week． (especially和particularly通用) 关于“创记录”的若干表达法 1) set up a world record创世界记录
Lessons 49~50 He likes... but he doesn't like... Words & Expressions: 生词和短语 meat beef lamb n. (食用)肉n. 牛肉n. 小羊, 羔羊grape steak mince n. 葡萄n. 牛排n. 碎肉，绞肉chicken tomato cabbage n. 小鸡, 鸡肉n. 番茄, 西红柿n. 卷心菜potato lettuce pea n. 马铃薯n. [植]莴苣n. 豌豆bean pear peach n. 豆n. 梨子n. 桃子either choice truth conj. 或者, 也n. 选择n. 事实 Sentence Patterns -1 重点句型-1 Do you want any meat today, Mrs Bird? 你今天要肉吗，夫人？ Yes, please. 是的，要。 Do you want beef or lamb? 你想要牛肉还是要小羊肉？Beef, please. 请给我牛肉。 I like lamb, but my husband doesn't.我喜欢小羊肉，但我丈夫不喜欢。What about some steak? This is a nice piece. 来些牛排，好吗？这块就很好。Give me that piece please 请给我那一块吧。 And a pound of mince, too. 我还要一磅绞肉。
Sentence Patterns - 2 重点句型-2 Do you want a chicken, Mrs Bird? They're very nice. 你要一只鸡吗，伯德夫人？ No, thank you. 不要啦，谢谢。 My husband likes steak, but he doesn't like chicken. 我丈夫喜欢牛排，但他不喜欢鸡。To tell you the truth, Mrs Bird, I don't like chicken, either！ 说实话，伯德夫人，我也不喜欢鸡！ Sentence Patterns Review 重点句型复习 Do you like coffee, Mrs Price? 你喜欢咖啡吗，普莱斯夫人？ Yes, I do. 是的，我喜欢。 Do you want a cup? 你要一杯吗？ Yes , please, Mrs Young. 好的，杨夫人。 Do you want any milk? 你要放点牛奶吗？ No, thank you. 不要，谢谢你。 I don't like milk in my coffee. I like black coffee.我不喜欢咖啡中加牛奶。 我喜欢不掺牛奶的咖啡。
真空泵选型 真空泵的作用就是从真空室中抽除气体分子，降低真空室内的气体压力，使之达到要求的真空度。概括地讲从大气到极高真空有一个很大的范围，至今为止还没有一种真空系统能覆盖这个范围。因此，为达到不同产品的工艺指标、工作效率和设备工作寿命要求、不同的真空区段需要选择不同的真空系统配置。为达到最佳配置，选择真空系统时，应考虑下述各点： 确定工作真空范围: ----首先必须检查确定每一种工艺要求的真空度。因为每一种工艺都有其适应的真空度范围，必须认真研究确定之。 确定极限真空度 ----在确定了工艺要求的真空度的基础上检查真空泵系统的极限真空度，因为系统的极限真空度决定了系统的最佳工作真空度。一般来讲，系统的极限真空度比系统的工作真空度低20%，比前级泵的极限真空度低50%。 被抽气体种类与抽气量 检查确定工艺要求的抽气种类与抽气量。因为如果被抽气体种类与泵内液体发生反应，泵系统将被污染。同时必须考虑确定合适的排气时间与抽气过程中产生的气体量。 真空容积 检查确定达到要求的真空度所需要的时间、真空管道的流阻与泄漏。 考虑达到要求真空度后在一定工艺要求条件下维持真空需要的抽气速率。 主真空泵的选择计算 S=2.303V/tLog(P1/P2) 其中： S为真空泵抽气速率(L/s) V为真空室容积（L） t为达到要求真空度所需时间(s)
P1为初始真空度(Torr) P2为要求真空度(Torr) 例如： V=500L t=30s P1=760Torr P2=50Torr 则: S=2.303V/t Log(P1/P2) =2.303x500/30xLog(760/50) =35.4L/s 当然上式只是理论计算结果，还有若干变量因素未考虑进去，如管道流阻、泄漏、过滤器的流阻、被抽气体温度等。实际上还应当将安全系数考虑在内。目前工业中应用最多的是水环式真空泵和旋片式真空泵等 一般的要求是： 1、真空度、真空容积、主要介质、温度、主要容积类设备。 2、真空流入介质及流量、压力、温度、规律。 3、抽气量、抽出气体介质、温度。 4、真空设备的占地面积、自动化程度、真空管道规格 选用真空泵时需要注意事项： 1、真空泵的工作压强应该满足真空设备的极限真空及工作压强要求。如：真空镀膜要求1×10-5mmHg的真空度，选用的真空泵的真空度至少要5×10-6mmHg。通常选择泵的真空度要高于真空设备真空度半个到一个数量级。 2、正确地选择真空泵的工作点。每种泵都有一定的工作压强范围，如：扩散泵为10-3~10-7mmHg，在这样宽压强范围内，泵的抽速随压强而变化，其稳定的工作压强范围为5×10-4~5×10-6mmHg。因而，泵的工作点应该选在这个范围之内，而不能让它在10-8mmHg下长期工作。又如钛升华泵可以在10-2mmHg下工作，但其工作压强应小于1×10-5mmHg为好。
【知识点讲解】 1. 今天还是继续熟悉一般过去式。我们看到在课文一开始就用Last week 来点明事件发生的 时间，把整个语境都摆到了过去的状态里。有同学可能会问：那第二句也用到 She does not know London very well... 这里也是一般现在时态啊!我们要注意的是，这里说“米尔斯夫人不熟悉伦敦”是一个持续的状态，不是说米尔斯夫人在上周才不熟悉伦敦，而是她一直以来都不熟悉，所以这里前半句用的是一般现在时态，紧跟着的一句“she lost her way ” 又回到一般过去式了。 2. 还是第二句中“...and she lost her way.” 这里我们看到中文的翻译是“所以她迷路了”。这并不是说and 的意思可以是“所以”，and 还是“以及、和”的意思，这里只是用中文惯式的连词“所以”来翻译了这个意思而已。 3. 今天又学到了两个不规则的动词过去变化，大家要特别记忆一下：speak - spoke;understand - understood 。另外再顺便记一个：stand - stood ，站立。 Lesson73 Last week Mrs. Mills went to London. She does not know London very well, and she lost her way. Suddenly, she saw a man near a bus stop. 'I can ask him the way.' She said to herself. 'Excuse me,' she said. 'Can you tell me the way to King Street, please?' The man smiled pleasantly. He did not understand English! He spoke German. He was a tourist. Then he put his hand into his pocket, and took out a phrasebook. He opened the book and found a phrase. He read the phrase slowly. 'I am sorry,' he said. 'I do not speak English.' 上星期米尔斯夫人去了伦敦。她对伦敦不很熟悉，因此迷了路。 突然，她在公共汽车站附近看到一个男人。“我可以向他问路，”她想。 “对不起，您能告诉我到国王街怎么走吗?”她说。 这人友好地笑了笑。他不懂英语!他讲德语。他是个旅游者。 然后他把手伸进了衣袋，掏出了一本常用语手册。 他翻开书找到了一条短语。他缓慢地读着短语。 “很抱歉，” 他说，“我不会讲英语。”
学习-----好资料 Lesson 72 A Famous Clock 一个著名的大钟【Text】 The great racing driver, Sir Malcolm Campbell, was the first man to drive at over 300 miles per hour. He set up a new world record in September 1935 at Bonneville Salt Flats, Utah. Bluebird, the car he was driving, had been specially built for him. It was over 30 feet in length and had a 2,500-horsepower engine. Although Campbell reached a speed of over 304 miles per hour, he had great difficulty in controlling the car because a tyre burst during the first run. After his attempt, Campbell was disappointed to learn that his average speed had been 299 miles per hour. However, a few days later, he was told that a mistake had been made. His average speed had been 301 miles per hour. Since that time, racing drivers have reached speeds over 600 miles an hour. Following in his father's footsteps many years later, Sir Malcolm's son, Donald, also set up a world record. Like his father, he was driving a car called Bluebird. 【课文翻译】 杰出的赛车选手马尔科姆.坎贝尔爵士是第一个以每小时超过300英里的速度驾车的人。他于1935年9月在犹他州的邦纳维尔盐滩创造了一项新的世界纪录。他驾驶的“蓝鸟”牌汽车是专门为他制造的。它的车身长30英尺，有一个2,500 马力的发动机。尽管坎贝尔达到了每小时超过304英里的速度，但他很难把汽车控制住，因为在开始的行程中爆了一只轮胎。比赛结束后，坎贝尔非常失望地得知他的平均时速是299英里。然而，几天之后，有人告诉他说弄错了。他的平均时速实际是301英里。从那时以来，赛车选手已达到每小时600英里的速度。很多年之后，马尔科姆爵士的儿子唐纳德踏着父亲的足迹，也创造了一项世界纪录。同他父亲一样，他也驾驶着一辆名叫“蓝鸟”的汽车。 New words and expressions 生词和短语
新概念英语单词第一册第73 课：到国王街的走法 【单词例句】 A：How long will the meeting last? A:这次的会议要持续多长时间？ B：It will last for about one week. B:大约要持续一周时间。 London ['lndn] 伦敦 sudde nly ['sd() nl ] adv.突然地 【单词例句】 A: I feel quite embarrassed for suddenly having to makethis kind of request. A:突然不得不提出这样的请求，实在不好意思。 B: It doesn't matter. Go ahead, please. B:没关系，请说吧。 bus [bs] stop [stp]公共汽车站 smile [smal]微笑 【单词例句】 A: To go to the English Comer is to give you a goodchance to open your mouth to speak. A:去英语角就是给你一个开口说英语的好机会。 B: MaybeI can go thereto have a try. B:也许我能够去那儿试一试。 hand [hnd] 手
【派生词】handkerchief 手帕 【单词扩充】arm 手臂 【单词搭配】hand in hand手牵于ha nds up举手give a hand协助 【单词例句】 A：Hold the steering wheel with your hands at teno'clock and two o'clock. A. 把手握在方向盘的10点及2点钟方向。 B：And what shallI do then? B:我接着该这么做？ pleasantly ['plezntli]adv 愉快地 understand ['plezntli] 懂，明白 【派生词】understanding 理解nusunderstand 误解 【单词搭配】understand each other 互相了解 【单词例句】 A: We have to be fair about these things A:对这种事情，我们一视同仁。 B: I understand your position. B. 处在你们的位置，这样做我很理解。 speak [spik]讲，说 【派生词】speaker 喇叭 【单词扩充】relate 叙述say 说，讲 【单词搭配】speak out 大声说speak on 继续说
新概念英语第二册Lesson70 Red for danger Lesson 70 Red for danger 危险的红色 First listen and then answer the question. 听录音，然后回答以下问题。 How was the drunk removed from the ring? During a bullfight, a drunk suddenly wandered into the middle of the ring. The crowd began to shout, but the drunk was unaware2 of the danger. The bull1 was busy with the matador3 at the time, but it suddenly caught sight of the drunk who was shouting rude remarks and waving a red cap. Apparently4 sensitive to criticism, the bull forgot all about the matador and charged at the drunk. The crowd suddenly grew quiet. The drunk, however, seemed quite sure of himself. When the bull got close to him, he clumsily stepped aside to let it pass. The crowd broke into cheers and the drunk bowed. By this time, however, three men had come into the ring and they quickly dragged the drunk to safety. Even the bull seemed to feel sorry for him, for it looked on sympathetically until the drunk was out of the way before once more turning its attention to the matador. New words and expressions 生词和短语 bullfight n. 斗牛 drunk n. 醉汉 wander v. 溜达，乱走 ring n. 圆形竞技场地
真空泵基础知识及选型指导 一、基础知识 1、真空的概念 “真空”一词来自拉丁语“vacuum”，原意为“虚无”、“空的”。真空是指在给定空间内低于环境大气压力的气体状态，即该空间内的气体分子密度低于该地区大气压力的气体分子密度，并不是没有物质的空间。水环真空泵应用于低真空（105—103 Pa）领域 2、真空的测量单位 在真空技术中，表示处于真空状态下气体稀薄程度的量称为真空度，可用压力、分子数密度、平均自由程和形成一个单分子层的时间常数等来表征，但通常用气体的压力（剩余压力）值来表示。气体压力越低，表示真空度越高；反之，压力越高，真空度越低。 法定的压力计量单位为帕［帕斯卡］，符号为Pa 1Pa=1N.m-2 此外，还可用真空度的百分数作测量单位。 δ——真空度百分数（%）P——绝对压力（Pa）Pb-P 表示真空压力表读数，表压力（用Pe表示）真空度百分数δ（%）与压力P对照表 3、单位换算 1atm（标准大气压）=1013.25hPa（百帕） 1mmHg（毫米汞柱）=1Torr（托）=1.333 hPa（百帕） 1bar（巴）=1000 hPa（百帕） 1mbar（毫巴）=1 hPa（百帕）
１inHg（英寸汞柱）=25.4mmHg（毫米汞柱）=33.8 hPa（百帕） 4、相关术语 ◇气量——水环真空泵的气量是指入口在给定真空度下，出口为大气压1013.25hPa时，单位时间通过泵人口的吸入状态下的气体容积，m3/min 或m3/h 。 ◇最大气量——水环真空泵的最大气量是指气量曲线上的气量最大值，m3/min或m3/h。 ◇真空度（或称作压力）——水环真空泵的真空泵是指入口处在真空状态下气体的稀薄程度，以绝对压力表示，Pa、hPa、kPa。 ◇极限真空度（或称作极限压力）——水环真空泵的极限真空度是指入口处气量为零时的真空度，Pa、hPa、kPa。 ◇压缩比——吸入压力下气体容积与压缩后气体容积之比 ◇饱和蒸汽压——在给定温度下，某种物质的蒸汽与其凝聚相处于相平衡状态下的该种物质的蒸汽压力。 二、选型指导 真空泵的工作压力应该满足真空设备的极限真空及工作压力要求。通常选择泵的真空度要高于真空设备真空度半个到一个数量级。2BVX、2BEX 系列真空泵吸气压力范围在33hPa——1013.25 hPa之间，在此范围内，气量随吸气压力的不同而变化。根据气量和真空度选择合适的泵。保证工艺要求的真空度或抽走需要排走的气体。泵的工作点尽可能要求在高效区
新概念英语第二册第72课听力：A car called bluebird Lesson 72 A car called Bluebird“蓝鸟”汽车 First listen and then answer the question. 听录音，然后回答以下问题。 What mistake was made? The great racing driver, Sir Malcolm Campbell, was the first man to drive at over 300 miles per hour. He set up a new world record in September 1935 at Bonneville Salt Flats, Utah. Bluebird, the car he was driving, had been specially built for him. It was over 30 feet in length and had a 2,500-horsepower engine. Although Campbell reached a speed of over 304 miles per hour, he had great difficulty in controlling the car because a tyre burst during the first run. After his attempt, Campbell was disappointed to learn that his average speed had been 299 miles per hour. However, a few days later, he was told that a mistake had been made. His average speed had been 301 miles per hour. Since that time, racing drivers have reached speeds over 600 miles an hour. Following in his father's footsteps many years later, Sir Malcolm's son, Donald, also set up a world record. Like his father, he was driving a car called Bluebird. 参考译文 杰出的赛车选手马尔科姆.坎贝尔爵士是第一个以每小时超过300英里的速度驾车的人。他于1935年9月在犹他州的邦纳维尔盐滩创造了一项新的世界纪录。他驾驶的“蓝鸟”牌汽车是专门为他制造的。
Lesson 70 Red for danger 危险的红色 【Text 】During a bullfight, a drunk suddenly wandered into the middle of the ring. The crowd began to shout, but the drunk was unaware of the danger. The bull was busy with the matador at the time, but it suddenly caught sight of the drunk who was shouting rude remarks and waving a red cap. Apparently sensitive to criticism, the bull forgot all about the matador and charged at the drunk. The crowd suddenly grew quiet. The drunk, however, seemed quite sure of himself.When the bull got close to him, he clumsily stepped aside to let it pass. The crowd broke into cheers and the drunk bowed. By this time, however, three men had come into the ring and they quickly dragged the drunk to safety. Even the bull seemed to feel sorry for him, for it looked on sympathetically until the drunk was out of the way before once more turning its attention to the matador. 【课文翻译】 在一次斗牛时，一个醉汉突然溜达到斗牛场中间，人们开始大叫起来，但醉汉却没有意识到危险。当时那公牛正忙于对付斗牛士，但突然它看见了醉汉，只见他正大声说着粗鲁的话，手里挥动着一顶红帽子。对挑衅显 然非常敏感的公牛完全撇开斗牛士，直奔醉汉而来。观众突然静了下来，可这醉汉像是很有把握似的。当公牛逼近他时，他踉跄地住旁边一闪，牛扑空了。观众欢呼起来，醉汉向人们鞠躬致谢。然而，此时已有 3个人 进入斗牛场，迅速把醉汉拉到安全的地方。好像连牛也在为他感到遗憾，因为它一直同情地看着醉汉，直到他的背影消逝，才重新将注意力转向斗牛士。 New words and expressions 生词和短语 【生词讲解】 1.bullfight n. 斗牛（活动） bull n. 公牛 cow n. 母牛，奶牛 ox 大公牛(oxen, pl. ) calf 小牛 bull market 牛市（股市行情很好） bear market 熊市（股市行情不好） bully n. 恃强凌弱的人bullfight n. 斗牛drunk n. 醉汉wander v. 溜达，乱走ring n. 圆形竞技场地unaware adj. 不知道的，未觉察的bull n. 公牛matador n. 斗牛士 remark n. 评论；言语 apparently adv. 明显地 sensitive adj. 敏感的 criticism n. 批评 criticism n. 批评 charge v. 冲上去 clumsily adv. 笨拙地 bow v. 鞠躬 safety n. 安全地带 sympathetically adv. 同情地
产品名称：2BE 水环式真空泵
一、2BE水环式真空泵特点及用途： 2BE水环式真空泵及压缩机，是我厂在多年科研成果和生产经验的基础上，结合进口产品先进技术，研制开发的高效节能产品。通常用于抽吸不含固体颗粒，不溶于水，无腐蚀性的气体，以便在密闭容器中形成真空和压力。通过改变结构材料，亦可用于抽吸腐蚀气体或以腐蚀性液体做工作液。广泛用于造纸、化工、石化、轻工、制药、食品、冶金、建材、石器、洗煤、选矿、化肥等行业。 由于在工作过程中，该泵对气体的压缩是等温状态下进行，因此可抽吸易燃.易爆气体，通过改变结构材料，亦可抽吸腐蚀性气体货以腐蚀性液体作工作液。 2BE水环式真空泵采用单级单作用的结构形式，具有结构简单，维修方便，运行可靠，高效节能的优点。相对于目前国内广泛使用的SK、2SK、SZ系列水环式真空泵具有真空度高、功耗低等显著优点，是SK、2SK、SZ系列水环式真空泵理想替代产品 我公司生产的2BE型水环式真空泵及压缩机结构主要特点如下： 2BE型水环式真空泵的轴承全部采用NSK或NTN原装进口轴承，保证了2BE1真空泵的叶轮精确定位及运转过程中的高稳定性。 2BE型水环式真空泵的叶轮材质全部采用球墨铸铁铸造或钢板、不锈钢板焊接，充分保证了2BE1真空泵叶轮在各种恶劣工况下的稳定性，且大大 提高了2BE1真空泵的使用寿命。 泵体全部采用钢板或不锈钢板制作，提高了2BE1真空泵的使用寿命。 2BE1真空泵的轴套作为最易损坏的零件，本公司全部采用不锈钢制作，比普通材质寿命提高了5倍。 皮带轮（皮带传动）采用标准高精度锥套皮带轮，运行可靠，皮带寿命长，拆卸方便。 联轴器（直联传动）采用标准高强度弹性联轴器，弹性元件采用聚氨酯材质，运行稳定可靠，使用寿命长。 独特的上置式气水分离器节约空间，并有效降低了噪声。 铸件全部采用树脂砂铸造，表面质量好。铸件表面无需打腻，使2BE1真空泵散热效果最佳。 机械密封（选配件）全部采用进口件，充分保证2BE1系列真空泵在长时间运行过程中无泄漏。 二.2BE水环式真空泵特点: 1.高可靠性 由于该系列泵采用叶轮与轴热装过盈配合，轴与轴承安全系数大，因而具有相当搞的可靠性，叶轮采用焊接，轮及叶片全部加工，从根本解决了动平衡问题，运转平稳底噪音。 2.维护方便 由于在泵的端盖上没有设置检查孔，因而可以方便地查看内部结构，并无需拆泵便可更换排气阀板，此外填料的更换也可在不拆泵的情况下进行，释放方便。 3.高效节能 该系列泵采用系统优化设计，采用了柔性排气阀设计，避免了气体压缩中的过压缩，通过调节排气面积降低能量消耗，最终达到最佳运行效率。 4.适应冲击载荷 叶片采用钢板一次山冲压成型，型线得以保证，焊接叶轮整体进行热处理，叶片具有良好韧性，其抗冲击.
Lesson 72 A Famous Clock 一个著名的大钟【Text】 The great racing driver, Sir Malcolm Campbell, was the first man to drive at over 300 miles per hour. He set up a new world record in September 1935 at Bonneville Salt Flats, Utah. Bluebird, the car he was driving, had been specially built for him. It was over 30 feet in length and had a 2,500-horsepower engine. Although Campbell reached a speed of over 304 miles per hour, he had great difficulty in controlling the car because a tyre burst during the first run. After his attempt, Campbell was disappointed to learn that his average speed had been 299 miles per hour. However, a few days later, he was told that a mistake had been made. His average speed had been 301 miles per hour. Since that time, racing drivers have reached speeds over 600 miles an hour. Following in his father's footsteps many years later, Sir Malcolm's son, Donald, also set up a world record. Like his father, he was driving a car called Bluebird. 【课文翻译】 杰出的赛车选手马尔科姆.坎贝尔爵士是第一个以每小时超过300英里的速度驾车的人。他于1935年9月在犹他州的邦纳维尔盐滩创造了一项新的世界纪录。他驾驶的“蓝鸟”牌汽车是专门为他制造的。它的车身长30英尺，有一个2,500 马力的发动机。尽管坎贝尔达到了每小时超过304英里的速度，但他很难把汽车控制住，因为在开始的行程中爆了一只轮胎。比赛结束后，坎贝尔非常失望地得知他的平均时速是299英里。然而，几天之后，有人告诉他说弄错了。他的平均时速实际是301英里。从那时以来，赛车选手已达到每小时600英里的速度。很多年之后，马尔科姆爵士的儿子唐纳德踏着父亲的足迹，也创造了一项世界纪录。同他父亲一样，他也驾驶着一辆名叫“蓝鸟”的汽车。 New words and expressions 生词和短语 【生词讲解】 1.racing 竞赛 race 1) n 速度竞赛[c]
在真空泵选型前，我们一定弄清楚几个基础概念： 真空理论上是指容积里面不含有任何的物质。（现实中是不存在真正的真空的）通常把容器内气压低于正常大气压（101325 Pa）的都称之为真空状态。 真空度表示处于真空状态下的气体稀簿程度，通常用压力值来表示。实际应用中，真空度通常有绝对真空和相对真空两种说法。从真空表所读得的数值称真空度。真空度数值是表示出系统压强实际数值低于大气压强的数值，从表上表示出来的数值又称为表压强，业界也称为极限相对压强，即：真空度=大气压强-绝对压强(大气压强一般取101325Pa，水环式真空泵极限绝对压强3300Pa；旋片式真空泵极限绝对压强约10Pa) 绝对真空&相对真空 极限相对压强相对压强即所测内部压强比“大气压”低多少压强。表示出系统压强实际数值低于大气压强的数值。由于容器内部空气被抽，因此内部的压强始终低于容器外部压强。所以当用相对压强或者表压强表示的时候，数值前面须带负号，表示容器内部压强比外部压强低。 极限绝对压强绝对压强即所测内部压强比”理论真空(理论真空压强值为0Pa)”高多少压强。它所比较的对象为理论状态的绝对真空压强值。由于工艺所限，我们无论如何都不能将内部压强抽到绝对真空0Pa这个数值，因此，真空泵所抽的真空值比理论真空值要高。所以当用绝对真空表示时，数值前面无负号。
例如，设备的真空度标为0.098MPa，实际上是-0.098MPa 抽气量抽气量是真空泵抽速的一个衡量因素。一般单位用L/S和m3/h来表示。是弥补漏气率的参数。不难理解，理论下抽一个相同体积的容器，为什么抽气量大的真空泵很容易抽到我们所需的真空度，而抽气量小的真空泵很慢甚至无法抽到我们想要的真空度？因为管路或者容器始终不可能做到绝对不漏气，而抽气量大的弥补了漏气所带来的真空度下降的因素，所以，大气量的很容易抽到理想真空度值。这里建议，在计算出理论抽气量的情况下，我们尽量选择高一级的抽气量的真空泵。抽气量具体计算公式以下会介绍。 他们Pa, KPa, MPa, mbar, bar, mmH2O, Psi之间的换算方式如下表： 下面进入真空泵的选型。 1、工艺要求达到的真空度 真空泵的工作压力应该满足工艺工作压力要求，选型时真空度要高于真空设备真空度的半个到一个数量级。(如：真空工艺要求100pa(绝对压力)的真空度，选用真空泵的真空度至少要50pa-10pa)。一般如果要求绝对压强高于3300Pa则优先选择水环式真空泵作为真空装置，如果绝对压强要求低于3300Pa，则不能选择水环式真空泵，选择旋片式真空泵或更高真空级别的真空泵作为真空获得装置。 2、工艺要求的抽气量(抽气速率) 真空泵要求抽气速率(即要求真空泵在其工作压力下，排出气体、液体，固体的能力)，一般
Text The great racing driver, Sir Malcolm Campbell, was the first man to drive at over 300 miles per hour. Sir 爵士，冠于爵士或准爵士的名字之前或名字与姓之前（但不可只用于姓之前）Sir Edward 爱德华爵士 Sir John Jackson 约翰.杰克逊爵士 Duke 公爵 Marquis 侯爵 Earl 伯爵 viscount 子爵 baron 男爵 drive at 以…速度驾车 (at 介词， 以…（速度，价格，比率等） eg The train was traveling at 100 kilometers an hour. 火车以每小时一百公里的速度行驶。 eg We drove at top speed.我们急速行驶。 （top speed 最高的速度）eg drive at 意指，打算 eg What are you driving at ? 你有什么打算？ He set up a new world record in September 1935 at Bonneville Salt Flats, Utah. set up a new world record / built up a new world record 创造新的世界纪录 make a new world record / create a new world record 创造新的世界纪录(口） Bluebird, the car was driving , had been specially built for him. the car was driving 是 Bluebird 的同位语，意思是他所驾驶的蓝鸟汽车。 build 1v 建造 be built for 为…建造被动结构 build for 为…建造主动结构 eg build up 树立，建立 build up one`s 积累财富 build …on/ build... upon 奠定基础,奠定…的基础于… eg Our business is built on trust. 我们的生意建立在信任的基础上。 2n 体格，造型 a man of strong 体格健壮的男人 builder n building n 建筑物 a high-rise building 高楼建筑 school building 校舍 It was over 30 feet in length and had a 2,500-horsepower engine. in length 在长度上 long adj 长的 length n 长度 in width 在宽度上 width n 宽度 wide adj 宽的 in height 在高度上 high adj 高的 at full length 伸展全身 eg He lay at full length on the grass.他伸展全身躺在草地上。 at length tell a story at length 详细地讲一个故事I bought these neckties at (the price of ) 10 dollars each. 我以每条10美元的价格买了这些领带。（at the price of 以…价格） The great racing driver ， Sir Malcolm Campbell ， was the first man to drive at over 300 miles per hour. He set up a new world record in September 1935 at Bonneville Salt Flats ， Utah. Bluebird ， the car he was driving ， had been specially built for him. It was over 30 feet in length and had a 2，500-horsepower engine. Although Campbell reached a speed of over 304 miles per hour ， he had great difficulty in controlling the car because a tyre burst during the first run. After his attempt ， Campbell was disappointed to learn that his average speed had been 299miles per hour. However ， a few days later ， he was told that a mistake had been made. His average speed had been 301 miles per hour. Since that time ， racing drivers have reached speeds over 600 miles an hour. Following in his father's footsteps many years later ， Sir Malcolm's son ， Donald ， also set up a world record. Like his father ， he was driving a car called Bluebird. He built a doghouse for his dog. 他为他的狗搭建了一个狗窝。 最后/ 详细地，絮叨地 建设者，建立者，创建者