whereas

2007-10-28   来源:生物课件

详解ago与before的语法难点
篇一:whereas

  1. before还是ago?

  要说:

  I came to Manchester two weeks ago.I came to Manchester two weeks ago.

  不要说:

  I came to Manchester before two weeks.

  Use "past time + ago"

  ago用于一般过去时,例如:

  10 years ago, a long time ago, a few weeks ago, a couple of days ago

  Use "before + action / event"

  before用于动作或事件前,例如:

  before you left, before we start, before lunch

  2. fall 还是reduce?

  These two words are the opposites of 'rise' and 'raise':

  它们是rise和raise的反义词:

  something falls (e.g. the price fell)

  somebody reduces something (e.g. the company reduced the price)

  You will probably use 'fall' to describe numbers on a graph or chart for IELTS Writing Task 1:

  在雅思短作文中,你可以用fall来描述图表里的数字。

  In 2008, the number of customers fell. (verb, past)

  这里的fall是动词,过去时。

  There was a sharp fall in Internet usage. (noun)

  这里的fall是名词。

  'Reduce' and 'reduction' are probably more useful for Writing Task 2:

  reduce和reduction在长作文中更有用:

  We need to reduce the amount of pollution from exhaust fumes. (verb)

  reduce,动词。

  Recycling leads to a reduction in waste. (noun)

  reduction,名词。

  3. because还是because of?

  Compare these two sentences:

  比较下列两个句子:

  I stayed at home because the weather was bad.

  I stayed at home because of the bad weather.

  The important difference is the use of the word 'was' in the first sentence. After 'because', you need a subject and a verb (e.g. the weather was). After 'because of', we don't use a verb, only a noun, nouns or noun phrase.

  重要的区别在于第一句里使用了word。Because后面需要加主语和动词(例如the weather was)。Because of 后面不需要动词,只要一个或多个名词,又或者名词词组就可以了。

怎样通过BEC商务英语考试的经验分享
篇二:whereas

  随着中国经济与世界经济日益接轨,社会对掌握商务英语交流技能人才的需求也不断扩大.为了顺应这种发展趋势,一些国际性的商务英语考试在中国流行起来,而通过这些考试所获得的证书或成绩也被越来越多的组织和公司所认可,成为招聘和升职加薪的重要依据.目前的商务英语考试种类较多,主要有剑桥商务英语、托业考试和博思职业英语等,研究这些考试的权威性、形式和适用对象,对于面对繁多的商务英语考试而无所适从的应试者具有现实的意义.

  怎样通过BEC商务英语考试的经验分享

  写作

  写作的重要性大家都很清楚,我想说一下,具体到BEC这个考试中写作的重要性,剑桥商务英语真题集前言中有一段话是考试的评分规则,即在相同的总分下写作分数高的试卷将会被给与更高的等级,并且最后给试卷等级的时候主考官要征求写作部分阅卷老师的意见,可见优秀的写作能力在BEC考试中有多么重要。

  第一部分

  本部分是给定图线或者表格,要求考生描述题目给定信息的趋势,题目要求很简单,但是真正写的时候才发现在要求的120-140字的范围内要把图表中横向纵向的比较用不重复简洁有效的文字表述出来并非想象中的那么容易。

  其实题目的信息很容易读懂,关键问题在于怎么样忠实于题目将原本枯燥的数字或者曲线描述出来,又不让人感觉冗杂沉闷。

  关键在于常用句型、关联词的积累,文章的结构要清晰易懂,层次明确,重点信息突出,借助于图表的特征数值来写。单纯的数字累加相当于流水账,连Band 2都得不了。

  这一部分的技巧在于首先抓住整个变化区间最核心最明显最重要的趋势确定文章的行文路线和方法。首句就要给出全文的趋势,比如:销售量大幅上升或者在最近的几年里该公司股票价格反复波动等等。确定了大体框架之后,写进文章的就是信息了,中间穿插一些非常有用的词比如:double就很好,当然要看准数字再写。文章的转折、递进的处理和四六级作文相同。

  要注意的是,你所要做的只是描述趋势信息,不要题外发挥,题目没给的一点也不要写,写了不但没用,还会倒扣分。看准题目要求,做好自己的本职工作就可以了,这也是商务活动的最基本的原则。

  尽量将自己的字数控制在题目规定的范围内,超过字数会被认为是概括能力不强,拖沓,同样会被扣分。

  第二部分

  本部分是写作的重头戏,也是真正显示高手水平的地方。不管是Report, Letter还是Proposal都要充分展示你的词汇、语法结构、句型的丰富,另一方面,从商业活动的角度来说又要明确而有效的给出对于题目所给实际问题的解决方案。

  市面上的参考书上包括剑桥习题集中有例文,后面还附有考官的评定等级和评语。要仔细揣摩考官评语,找出考官欣赏的写法,其实这也是一种向标准的商业写作进步的很好的一种方法。

  适量的背诵肯定是有好处的,但是目的不要局限在仅仅背诵这种形式上,学习别人的写法,把优秀的习惯变成自己的东西才能真正进步。

  考试的时候写作部分时间应该还算是充足,70分钟,但是不同人的情况不一样,也不好说写作就肯定容易,而且根据我个人感受要想写出Band 5的作文,平时要狠下功夫练习,给自己限时,考试的时候发挥也应当非常好。大致的印象是四六级作文写的还不错的同学大致能得到Band 3,呵呵,提升的空间太大了。

  参考资料上都有各种题材的基本的格式,真正的内容要充实、灵活,语法句式多变。200-250个字的要求限制里,要想尽一切办法展示出你的优秀的写作能力。很简单的比如,你肯定不能遇到转折就用but,你应该尝试着用however, nevertheless, whereas等等。一个意思的表示方法有很多种,对应的句式就有很多种,在作文里避免重复。

  文章的内容要逻辑合理,层次分明,这样考官才会认为你真正的具有从事商业活动写作的能力。论点明确,论据说服力强也是很重要的。

  在刚刚开始准备的阶段注意写作技巧的积累,到临近考试的2个月就要开始正式的训练了,写之前别看例文,写完之后再对照,你肯定会发现很多不足的地方,当然你也可能有比例文更优秀的地方,错的地方改正,不自然的地方改正,自己写的好的地方都作标记来源:考试大,什么时候你把自己的作文划的一塌糊涂的时候,你就真正是的在提高了。

  总之,写作的提高要靠练习,坚持不懈的练习,练的时候注意学习,充分利用范文和各种资源,一定能取得提高。

unit2 知识点
篇三:whereas

1.movie n. 电影

movie和film都是“电影”的意思,movie是美国英语用法,film是英国英语用法。“去看电影”的表达方式有:

go to see a film;go to a movie;go to see a movie;go to movies;go to the cinema

2.scary adj. 可怕的;吓人的;使人惊恐的

a scary moment惊恐时刻 a scary movie恐怖电影

The book is both scary and funny. 这本书的情节既恐怖又好笑。

3.thriller n. 使人毛骨悚然的东西;使人毛骨悚然的小说

I often borrow some thrillers to read. 我经常借一些恐怖小说读。

4.documentary n. 纪录片

I don’t like documentaries,because they are boring. 我不喜欢纪录片,因为它们太没意思了。

5.comedy n. 喜剧;喜剧性的事情

a comedy writer喜剧作家 a comedy show喜剧表演

the human comedy of political campaigns政治运动中人性的喜剧

6.exciting adj. 令人激动的;令人兴奋的however和whereas语法难点详解

这是动词excite的现在分词形式作形容词,主语通常是“物”。如:

an exciting discovery一个令人激动的发现

I’ve got some very exciting news for you.我给你带来了一些令人振奋的好消息。 Let’s do something exciting. 我们做一些令人兴奋的事情吧。

7.in a word总之;一句话

We are,in a word,busy. Very very busy. 总之,我们很忙,非常非常忙。 8.Beijing Opera=Peking Opera京剧

opera是“歌剧”的意思。如:

soap opera肥皂剧 opera house剧院;剧场 an opera singer歌剧演员

We go to the opera(=go to a performance of opera)regularly. 我们定期去看歌剧。 9.and conj. 和

and通常用来连接单词、词组和句子。表示一种并列或s顺接的关系。如: You and Tom will take part in the competition. 你和汤姆将要去参加比赛。

She read for an hour and went to bed. 她读了一小时的书,然后就去睡了。

10.but conj. 但是

but是连词,用来表示前后的转折关系。如:

I’d like to go but I’m too busy. 我愿意去但是我太忙了。

I was going to write,but I lost your address. 我本来是要写信的,可是把你的地址弄丢了。

和but用法相似的词还有:however,whereas,while等。

11.I don’t think...我认为……不……

think表示否定的时候,通常是否定后半部分,而不是前半部分。如:

I don’t think his decision is wise in fact. 实际上,我觉得他的决定并不明智。 He doesn’t think you are right. 他认为你不对。

12. 在一般现在时中,want(想要……)的用法和前边讲过的have和like的用法相似。否定式和疑问式都需要用助动词do和does;do用在第一人称、第二人称、第三人称复数和其他的复数名词前,does用在第三人称单数前。如: I want to go home now. 我现在想回家。

He wants to give you a surprise. 他想给你一个惊喜。

Do you want to play football with us? 你想和我们去踢足球吗?

Yes,I do./No,I don’t. 是的,我想去。/不,我不想去。

Does she want to marry that man? 她想和那个人结婚吗?

Yes,she does./No,she doesn’t. 是的,她想。/不,她不想。

课文探究

谈论喜好however和whereas语法难点详解

“谈论喜好、制订计划”是本单元的语言目标。你掌握了吗?一起来检测一下吧。

1. 你喜欢哪种电影?

What ________ ________ ________ do you like?

2. 我喜欢恐怖片但是不喜欢喜剧片。

I like thrillers ________ I don’t like comedies.

3. „„但我认为它很无聊。

... but ________ ________ it’s boring.

4. 迈克的父亲也喜欢它!

Mike’s father likes it, ________!

填好了吗?让我们一起来看看它们的用法吧。

1. What kind of movies do you like?

★ kind在此句中意为“种类”,是可数名词。a kind of意思是“一种”,all kinds of 意思是“各种各样的”。例如:

This is a kind of vegetable. 这是一种蔬菜。

All kinds of flowers are on sale.

各种各样的花在廉价出售。

2. I like thrillers but I don’t like comedies.

★ 本句为并列句,由but连接两个并列分句组成。并列句中的分句还可用并列连词and来连接。and在语意上有顺接的意思,而but在语意上有转折的意思。例如:

I like apples, and I like pears.

我喜欢苹果,也喜欢梨。

Vera likes milk, but she doesn’t like juice.

薇拉喜欢牛奶,但她不喜欢果汁。

3. ... but I think it’s boring.

★ think用作动词,意为“认为、想”,后面可跟一个完整的句子,即宾语从句,表示某人具体的看法。若think引导的宾语从句要表达否定的意思,通常否定要前移。即:否定词放在think前。例如:

I don’t think Jim is a good student.

我认为吉姆不是一个好学生。

4. Mike’s father likes it, too!

★ also和too作副词时,都有“也”的意思,但用法不同。also用法比较正式,一般用于肯定句,常位于动词前,有be动词、助动词时置于其后;too常用于肯定句,通常置于句末,有时也可放到句子中间。例如:

She is also a history teacher.

她也是一名历史老师。

They like English Weekly, too.

他们也喜欢《英语周报》。

【运用】

从方框中选择适当的词语完成对话。

also, and, what kind of, tooA: Hello, Mary! Do you often go to the movies?

B: Yes, I do.

movies do you like?

like documentaries. I can learn many things from them.

action movies. They are so exciting. I like Beijing Opera, like documentaries. They are boring.

课文探究 1. kind of movies 2. but 3. I think 4. too

[运用] 1. What kind of 2. also 3. and 4. too 5. don’t

语法聚焦

一般疑问句

【概念】

一般疑问句是请对方对所提问题给予肯定或否定答复的问句。

【结构】

1. 如果谓语动词是be,则把be提到主语前面。句式为“be + 主语 + 表语”。例如:Is this your bike? 这是你的自行车吗?

2. 如果谓语动词中有情态动词,要把这类动词提到主语前面。句式为“情态动词 + 主语 + 谓语动词 + 其它成分”。例如:Can you play tennis? 你会打网球吗?

3. 如果谓语动词为实义动词,就要借助于助动词do或does,将其放到主语前面,原来的动词用原形。 例如:Do you like swimming? 你喜欢游泳吗?

【回答】

一般疑问句的回答有肯定和否定两种。

肯定回答:Yes,主语 + be / 情态动词 / 助动词。

否定回答:No,主语 + be / 情态动词 / 助动词 + not。

【运用】

按要求完成下列句子。

1. I am a student.

(改为一般疑问句,并作肯定回答)

______________________________

2. Linda wants to see her aunt.

(改为一般疑问句,并作否定回答)

______________________________3. My brother can play volleyball.

(改为一般疑问句,并作肯定回答)

______________________________

土木专业英语unit3
篇四:whereas

Unite 3

Aerated concrete 加气混凝土

aggregate骨料,(混凝土的主要成分之一,分为粗骨料和细骨料两种。粗骨料是碎石或砾石,构成混凝土的骨架。细骨料是砂子,填充粗骨料之间的空隙;) 合计, 总计, 集合体

alkaline碱的, 碱性的

aluminum铝

arena 竞技场, 舞台; (古罗马的斗技场)比赛场所; arena of politics 政治舞台, 政界

the literary arena 文学界

beam [bi:m] n. 梁, 桁条, (光线的)束, 柱, 电波, 横梁

bearing wall 承重墙 bearing wheel 支承轮

bind 粘合,结合;binding agent 粘合剂,胶合剂

bitumen 沥青 blunt 钝的, 生硬的 bolt 螺栓杆,用螺栓固定

bond 结合(物), 粘结(剂), 联结, 公债, 债券, 合同

cast 浇筑,浇筑

cement 水泥,接合剂 vt. 接合, 用水泥涂, 巩固

clamp n.夹子, 夹具, 夹钳 vt.夹住, 夹紧

clay n. 粘土, 泥土, 肉体, 人体, 似黏土的东西, 陶土制的烟斗

column 圆柱, 柱壮物, 专栏, 纵队

concrete adj.具体的, 有形的 n. 混凝土v. 用混凝土修筑, 浇混凝土, 凝结

corrode 使腐蚀, 侵蚀

course 层,行 n. 过程, 经过, 进程, 方针, 路线, 跑道, 课程, 一道菜v追猎, 急行, 运行,

流动

curtain wall 幕墙

fatigue n. 疲乏, 疲劳, 累活, [军]杂役vt. 使疲劳, 使心智衰弱vi. 疲劳

form 模板 n. 形状, 形态, 外形, 表格, 形式v. 形成, 构成, 排列, (使)组成

framework构架, 框架, 结构

gravel砂砾, 砂砾层

grind 磨(碎), 碾(碎), 折磨

grout n. 薄泥浆, 水泥浆vt. 用薄泥浆填塞, (猪等)用鼻子拱

ingredient 组成部分,成分,配料,要素 成分, 因素

layer层, 阶层,夹层

mortar 砂浆 n. 臼, 研钵, 灰泥, 迫击炮vt. 用灰泥涂抹, 用灰泥结合

multistory building 多层建筑

no-fines concrete 无细骨料混凝土

pour 浇筑,倾倒 涌入, 流, 倾盆大雨

pozzolana 白榴火山灰,水泥与火山灰混合水泥 火山灰(可用作水泥原料)

prestressed concrete 预应力混凝土

pump 抽吸,泵送 (用泵)抽(水), 抽吸

rate of contraction 收缩率

rate of expansion 膨胀率

reinforced concrete 配筋混凝土,钢筋混凝土

rivet 铆钉,铆接 screw 螺丝钉;blunt screw 圆头螺丝钉,钝头螺栓

slab 平板,面板; roof slab 屋顶板;floor slab 楼板

span 跨度,孔距

spray 喷射

tarlike 像焦油的,焦油状的

tensile 拉力的,受力的,抗拉的 tensile strength 抗拉强度

tension 拉力,拉伸 thread 螺纹 tile 瓦片,瓷砖;hollow tile 空心砖

versatile 多用途的,万用的,通用的

volcanic 火山的,火山口的;volcanic ash 火山灰

weld 焊接 1.2 the characters of grammar 语法特点

(1)非人称的语气和客观态度,常使用it…结构

专业英语多描述客观事物、现象和规律。这一特点决定了科技人员在撰写科技文献时要采用客观和准确的手法陈述被描述对象的特性和规律、研究方法和研究成果等,而不需要突出人。因此,专业英语常常使用非人称的语气进行客观的叙述。

1. it is easier to make changes in design and to correct errors during construction (and at less expense) if welding is used.

若采用焊接,则在施工阶段更容易(以更少的费用)修改设计或改正错误。

例句中采用了it …is .结构,对某种事情或事实进行客观的描述,没有加人任何的主观色彩。句中的it表示to make … construction.

(2)较多使用被动语态

由于专业英语的客观性,决定了它非人称的表达方式,或者独者都知道动作的执行者是谁,或者不需要说明动作的执行者,因此,在专业英语中,较多地使用被动语态。

2.before any civil engineering project can be designed, a survey at site must be made.

在设计任何土木工程项目之前,必须进行现场测量。

(3)大量使用不定式、动名词、分词,多数情况下是为了使句子简洁和精炼。

3. the total weight being less,it is possible to build much taller buildings.

由于总重量减轻,才有可能建造更高的楼房。

4.the demands for sophisticated analysis, coupled with some serious limitations on computational capability,led to a host of special techniques for solving a corresponding set of special problems.

因为对精细分析的要求,但又受到计算能力的某些严重限制,由此产生了许多特殊方法以解决相应的一组特殊问题。

(4)较多的使用祈使语气和公式化表达方式

在理论分析和公式推倒中常用Assume that …,Suppose that …,Let…等祈使语气表达方式。 The huge investment in the infrastructure will be erased quickly if proper maintenance and rehabilitation procedures are enforced and funded

如果合理的养护和修复计划得以资助并实施,就可迅速取消用于基础建设的巨大投资。 If substituting Eq.(1) into (7).we obtain F=xyz.

若把式(1)代入式(7),则得到F=xyz

省略句较多

为了简洁,有时省略掉句子中的一些部分,如状语从句中的主语和谓语、定语从句中的关联词which或that、从句中的助动词等。

If not well managed,the procedure for construction may be more expensive

the characters of words and expressions 词汇特点

缩写词(Abbreviation)、数学符号(Mathematical symbol)及其表达式(Expression) Fig.(figure ) 图 Eq. (Equation) 方程(式) m/s(meter/second) 米/秒

In. (inch) 英寸 Eng.(Engineering) 工程 i.e. (拉丁语 id est) 也就是,即

etc (拉丁语et cetera) 等等

psi. (pounds per square inch) 磅/平方英寸

sym.(Symmetry or symmetrical) 对称

QC (Quality Control)质量控制

CDA (computer aided design)-计算机辅助设计

RILEM(Internationl Union of Testing and Research laboratorias for Materials and Structures) 国际材料与结构试验研究所联合会

FIDIC (International federation of Consulting Engineers)国际咨询工程师联合会

FIB ( International Federation for Structural Concrete) 国际结构混凝土联合会

CIB(International Council for Building Research Studies and Documentation)国际材料与结构试验研究所联合会 Unit 3

Structural Materials工程材料

Modern cement, called Portland cement, was invented in 1824. It is a mixture of limestone and clay, which is heated and then ground into a powder. It is mixed at or near the construction site with sand, aggregate(small stones, crushed rock, or gravel), and water to make concrete. Different proportions of the ingredients produce concrete with different strength and weight. Concrete is very versatile; it can be poured, pumped, or even sprayed into all kinds of shapes. And -whereas- steel has great tensile strength, concrete has great strength under compression. Thus, the two substances complement each other.

现在所说的水泥是1842年发明的指硅酸盐水泥,由石灰石和粘土经烧结并磨制成粉状而成。在建筑工地或工地附近,(将水泥)同砂、碎石(小石块、破碎的岩石、砾石)、水混合起来制成混凝土,不同的配料比例得到的混凝土的强度及承重,混凝土通用性强,可以灌注、泵送、甚至可以喷射成各种形状。鉴于钢筋的具有较强的抗拉能力,而混凝土具有较强的抗压能力,两类材料(性能)可以相互补充。

They also complement each other in another way: they have almost the same rate of contraction and expansion. They therefore can work together in situations where both compression and tension are factors. Steel rods are embedded in concrete to make reinforced concrete in concrete beams or structures where tension will develop. Concrete and steel also form such a strong bond—the force that unites them—that the steel cannot slip within the concrete. Still another advantage is that steel does not rust in concrete. Acid corrodes steel, whereas concrete has an alkaline chemical reaction, the opposite of acid.

钢筋、混凝土两类材料也可在其他方面相互补充,两类材料的伸缩率基本相同。他们可以在受压及受拉的情况下共同工作,钢条嵌于混凝土或受拉结构内以加强梁的强度。钢筋混凝土也可以形成较强的结合键—将二者结合在一起。钢筋在混凝土内不会滑脱,还有一个好处,那就是钢筋在混凝土内不会锈蚀。酸性物质可以腐蚀钢铁,而混凝土化学特性属碱性-与酸

性正相反。

The adoption of structural steel and reinforced concrete caused major changes in traditional consruction practices. It was no longer necessary to use thick walls of stone or brick for multistory builidings, and it became much simpler to build fire-resistant floors. Both these changes served to reduce the cost of construction. It also became possible to erect buildings with greater heights and longer spans.

钢和钢筋混凝土材料的使用在传统的建筑中发生了很大的变化。在多层建筑中没有必要使用后砖和石,建造防火的地板也变得容易了。这些变化也降低了建筑的花费。使建筑高层和大跨距的建筑成为可能。

Since the weight of modern structures is carried by the steel or concrete frame, the walls do not support the building. They have become curtain walls, which keep out the weather and let in light- In the earlier steel or concrete frame building, the curtain walls were generally made of masonry; they had the solid look of bearing walls承重墙. . Today, however, curtain walls are often made of lightweight materials such as glass, aluminum, or plastic, in various combinations.因为现在建筑中主要采用钢和混凝土骨架来承重,墙体不支撑建筑重量,而采用能够阻挡风雨和有力光线照入室内的幕墙,早期的钢和混凝土框架建筑物幕墙主要有砌筑而成,看起来像承重墙一样坚固,然而像在的幕墙主要有轻型的材料所构成, 如玻璃,吕,塑料,即多种组合而成。

Another advance in steel construction is the method of fastening together the beams. For many years the standard method was riveting. A rivet is a bolt with a head that looks like a blunt screw without threads. It is heated, placed in holes through the pieces of steel, and a second head is formed at the other end by hammering it to hold it in place. Riveting has now largely been replaced by welding, the joining together of pieces of steel by melting a steel material between them under high heat. 另外一先进的地方是将很多梁连接在一起的钢结构,很多年以来一直使用铆接的方法,铆接就是指这样的一种螺栓, 但这种螺栓没有螺纹线,把它穿过铁板上的孔,另一头放在铁板另一侧,用锤子砸紧固定住。现在铆接已被焊接所取代,焊接是指把溶化的钢材料两头焊在一起。

Prestressed concrete is an improved form of reinforcement. Steel rods are bent into the shapes to give them the necessary degree of tensile strength. They are then used to prestress concrete, usually by one of two different methods. The first is to leave channels in a concrete beam that correspond to the shapes of the steel rods. When the rods are run through the channels, they are then bonded to the concrete by filling the channels with grout, a thin mortar or binding agent. In the other (and more common) method, the prestressed steel rods are placed in the lower part of a form that corresponds to the shape of the finished structure, and the concrete is poured around them. Prestressed concrete uses less steel and less concrete. Because it is so economical, it is a highly desirable material.

预应力混凝土是钢筋混凝土的改进形式,钢条弯曲成一定形状以使其具有张紧度,用于形成预应力混凝土,通常有一到两种不同的方法来形成。第一种方法是在混凝土梁中留出与钢条形状相配的通道,当钢条通过通道时,用水泥浆---一种较稀的砂浆作为粘结剂,浇灌到通道里,使钢条与混凝土黏结在一起。另一种更常用的方式是将预应力钢条至于已成形结构的下部,然后浇筑混凝土,预应力混凝土所需的钢筋及混凝土较少,以其经济性,被视为一种较理想的建筑材料。

Prestressed concrete has made it possible to develop buildings with unusual shapes, like some of the modern sports arenas, with large spaces unbroken by any obstructing supports^11*. The uses for this relatively new structural method are constantly being developed.

预应力混凝土使得建造几何形状不规则的建筑物称为可能,像一些现代的体育馆,没有支撑物对空间形成影响,故空间很大,这种相对较新的建筑方式一直在持续发展中。

The current tendency is to develop lighter materials. Aluminum, for example, weighs much less than steel but has many of the same properties. Aluminum beams have already been used for bridge construction and for the framework of a few buildings.

当前的趋势是发展轻型材料,如铝,其质量较钢轻许多,但却同钢具有同样的性能,铝梁已经在桥梁建筑及少许建筑框架中被采用。

Lightweight concretes, another example, are now rapidly developing throughout the world.they are used for their thermal insulation. The three types are illustrated below:

另一个例子是轻型混凝土,因其阻热性好而在全球广泛应用, 有如下所示的三种类型:

(a) Concretes made with lightweight aggregates;

轻骨料混凝土

(b) Aerated concretes(US gas concretes) foamed by whisking or by some chemical process during casting;

加气混凝土通过搅拌起沫或在其定型过程中进行一些化学处理。 (c) No-fines concretes.

无细骨料混凝土

All three types are used for their insulating properties, mainly in housing, where they give high comfort in cold climates and a low cost of cooling in hot climates. In housing the relative weakness of lightweight concrete walls is unimportant, but it matters in roof slabs. floor, slabs and beams.

这三种类型都具有隔热性能,主要用于房屋建筑,在寒冷地区可以保持温度舒适没,而在酷热地区却已较低的成本降温。在房屋建筑中轻型混凝用于墙壁的建造中其相对弱点并不重要,但在屋面板,楼板及梁中期弱点就很明显。

In some locations, some lightweight aggregates cost little more than the best dense

aggregates and a large number of floor slabs have therefore been built of lightweight aggregate concrete purely for its weight saving, with no thought of its insulation value.在一些地区, 轻骨料的花费远低于重骨料,所以好多的楼板采用了轻骨料,只考虑减轻重量的问题,而没有考虑其隔热价值。 The lightweight aggregate reduces the floor dead load by about 20 per cent resulting in considerable savings in the floor steel in every floor and the roof, as well as in the column steel and (less) in the foundations.

因为采用轻骨料,楼板恒荷载降低了大约20%,大大降低了楼板,屋顶立柱及地基中的钢筋使用量。

One London contractor prefers to use lightweight aggregates because it gives him the same weight reduction in the floor slab as the use of hollow tiles, with simpler organization and therefore higher speed and profit. The insulation value of the lightweight aggregate is only important in the roof insulation, which is greatly improved

伦敦的承包商更愿意选择轻骨料作为建筑材料,因为采用轻骨料建立楼板所减轻的重量与采用空心瓷砖减轻的重量相近,因其组织简单,故可以获得较快的建筑速度和较高的利润。轻骨料的隔热价值对屋顶的隔热是最重

英语II(1) 重难点分析(1)
篇五:whereas

英语II(1) 重难点分析(1)

问题

短文理解1

East London has traditionally been an area which has attracted immigrants. The chance

to find jobs in London has led to immigrants from many different parts of the world living

there. Also, because it was the home of London's docks, it was easy for people to get there

by strip. One famous building in Brick Lane has been a church, a synagogue and is now a

mosque. Nowadays this part of London, which is known as the East End, is home to people

from many different parts of the world, including Africa, Asia and the Caribbean. This

means that there are many shops and restaurants selling ethnic food. In the past the East

End was one of the poorest parts of London, but now it is becoming more fashionable and

house prices are rising rapidly. This is because many people want to live near to where they

work in the centre of the city. Also improved transport links to both other parts of London

and to other countries via the Channel Tunnel train station and Docklands Airport have

attracted more people to the area.

1. East London

A. has never been a home for immigrants

whereas

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