健康的美好的用英语怎么读用语音回答我

healthy 英[u02c8helθi] 美[u02c8hu025blθi] adj. 健康的;健全的;大量的;有益于健康的 最高级:healthiest;比较级:healthier [例句]Raising a family and remaining healthy is enough of a battle.养家糊口并保持身体健康已经实属不易。

一、词性读音不同1、health的英式读法是[helθ]；美式读法是[helθ]。作名词意思是健康；医疗保健。2、healthy的英式读法是["helθi]；美式读法是["helθi]。作形容词意思是健康的。二、用法不同1、healthn. (名词)1）health的基本意思既可指人身体的“健康(可好可坏)”,也可指人精神上的“健康”,是不可数名词。2）health有时还可用作祝语,作“祝某人健康”解,可用作不可数名词,也可用作可数名词。2、healthyadj. (形容词)1）healthy作形容词的基本意思是“健康的,健壮的”,指人的身心处于良好的状态,很少生病。引申可作“(事物)兴旺发达,发展良好”解。2）healthy不能用来表示一时的健康,而是指一个长期的状态或过程。三、词汇搭配不同1、health1）affect sb"s health 影响某人的健康2）damage sb"s health 损害某人的健康3）drink health to sb 举杯祝某人健康2、healthy1）feel healthy 感觉身体健康2）grow healthy and strong 茁壮成长3）look healthy 看来身体很好

还l塞

读作，黑喔谁

1、health读音：英［helθ］，美［helθ］。释义：n. 健康；人的身体（或精神）状况；医疗；保健；卫生；状况。例句：Health care must be at the service of all who need it.医疗保健机构必须为所有需要者提供服务。短语：Health food绿色食品health condition健康状况Health Economics健康经济学2、fitness读音：英［u02c8fu026atnu0259s]，美［u02c8fu026atnu0259s]。释义：n. 健身；健康；健壮；适合（某事物或做某事）。例句：I"m taking the first tentative steps towards fitness.我试探性地开始实施健身计划。短语：fitness training健身训练psychological fitness心理健全fitness center健身中心physiological fitness生理适应能力3、well读音：英［wel]，美［wel]。释义：adv.很好地；相当地。int.好吧；啊。adj.健康的；良好的；适宜的。n.井；源泉；楼梯井。v.涌出。例句：Is she well enough to travel?她身体康复，能够旅行了吗？短语：very well很健康feel well觉得好look well看起来健康well in health身体健康4、soundness读音：英［u02c8sau028andnu0259s]，美［u02c8sau028andnu0259s]。释义：可靠性；坚固性；安定性；健全；完整性。例句：The life testing is one of the basic project of the soundness experiments.寿命试验是可靠性试验中的基本项目之一。短语：inference rule soundness推理规则的有效性soundness of feet四肢健实soundness of cement水泥固定性certificate of soundness合格证书5、wellness读音：英［u02c8welnu0259s]，美［u02c8welnu0259s]。释义：n.健康。例句：We have more medicine, but less wellness.医学越来越发达，我们的健康却每况愈下。短语：Health & Wellness卫生与健康Reiki Wellness唱片名a cure for wellness救命解药Health and wellness医疗服务区wellness programs身心健康方案

健康 [词典] health; healthy; physique; sound; [例句]一个人只要避免紧张，健康状况就会改善。A person"s health improves with the avoidance of stress.

读音：嗨欧sei。

1、healthy 。 2、读音：英 [u02c8helθi] 美 [u02c8hu025blθi]。 3、释义：adj.健康的；健全的；大量的；有益于健康的。 4、例句：Most of us need to lead more balanced lives to be healthy and happy 我们中大多数人需要过更为平衡的生活，以保持健康和快乐。

名词：health形容词：healthy副词：healthily

health的读音是：英[helθ]。health的读音是：英[helθ]。health的例句是用作名词(n.)Smoking is harmful to your health.吸烟对你的健康有害。health的意思是n.健康；医疗保健。一、详尽释义点此查看health的详细内容n.(名词)健康健康状况卫生，保健，医疗牢靠性人的身体状况昌盛，兴旺生命力，活力，体力，精力祝健康的干杯健全生机勃勃二、词典解释1.健康状况;身体状况A person"shealth is the condition of their body and the extent to which it is free from illness or is able to resist illness.e.g. Caffeine is bad for yourhealth.咖啡因对人体健康有害。2.健康Health is a state in which a person is not suffering from any illness and is feeling well.health的反义词e.g. In hospital they nursed me back tohealth.在医院里他们对我进行治疗及护理，使我恢复了健康。3.为…的健康干杯When youdrink to someone"shealth ordrink theirhealth, you have a drink as a sign of wishing them health and happiness.e.g. In the village pub, regulars drank thehealth of John and his father.在村子的酒馆里，老顾客们举杯祝愿约翰和他的父亲身体健康。4.兴旺;良好运行Thehealth of something such as an organization or a system is its success and the fact that it is working well.e.g. There"s no way to predict the futurehealth of the banking industry.银行业未来是否会兴旺发达根本无法预测。三、网络解释1. 健康状况：选择人物时主要注意他的年龄(Age)、健康状况(Health)、活力(Energy)和敏捷度(Dexterity). 年龄越大,活力恢复得越慢,健康状况也会逐渐恶化. 健康指数决定事业的成功与否,如果指数太低,会经常生病,甚至会早早去世,更谈不上什么事业.2.2. 卫生：在现代医学中,卫生(Health)包涵着两层意思,一是指防止疾病,是有关健康的各种卫生行为或活动的总称;二是指健康,即人的内环境与外环境之间的平衡状态(Health is a state of equilibrium between a human"s external and internal environment).3. health在线翻译3. 生命：游戏会员:F.Garland原创 一、属性 1.远程武器(Ranged Weapon) 提升弓与弩的杀伤力 2.生命(Health) 提升生命值上限 3.外交(Diplomacy) 改善他人对自己的态度,降低商人出售商品的价格 4.精力(Stamina) 提升精力最大值 5.医药(Medicine) 加强各种医疗用药的效...四、例句Smoking is harmful to your health.吸烟对你的健康有害。Fresh air and exercise are good for the health.新鲜空气和运动有益于健康。It is generally believed that health is above wealth.一般人都相信健康重于财富。Hospital mamagers are urging the government to spend more on health.医院的管理者们要求政府在医疗保健上加大支出。五、常用短语用作名词(n.)not for one"s health为了个人的利益〔目的〕 for one"s own profit六、经典引文This..period of alternating health and illness.出自：S. SpenderDr. Wasing"s astonishment..as M and B swept his pneumonia patients to health.出自：J. GathorneThe revenue from this source is essential for the continuing health of our journal.出自：Community Librarian七、常见错误n.(名词)吸烟对身体不好。误 Smoking is not good to your health.正 Smoking is not good for your health.析 “…对身体(不)好”应该用介词for,不可用to。他身体很糟,是吗?误 He is in a poor health, isn"t he?正 He is in poor health, isn"t he?析 health作“健康”解时是不可数名词,其前不能加不定冠词a。health的相关近义词strength、wholenesshealth的相关临近词healthy、healer、healthily、healthism、healthful、healthfood、Health men、health tea、Healthcard、health tin、healthwise、healthtron点此查看更多关于health的详细信息

健康的英语是health可以读嗨儿丝。

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healthy是形容词，没有过去式和过去分词

[healthylife]英语（英语：English）是一种西日耳曼语支，最早被中世纪的英国使用，并因其广阔的殖民地而成为世界使用面积最广的语言。英国人的祖先盎格鲁部落是后来迁移到大不列颠岛地区的日耳曼部落之一，称为英格兰。这两个名字都来自波罗的海半岛的Anglia。该语言与弗里斯兰语和下撒克森语密切相关，其词汇受到其他日耳曼语系语言的影响，尤其是北欧语（北日耳曼语），并在很大程度上由拉丁文和法文撰写。

healthy and wonderful life健康精彩的生活

adj.健康的;健全的;大量的;有益于健康的

健康作为形容词的英语单词是healthy，比较级是healthier，读音谐音是：海偶西额

一.两者作为“卫生的”、“有益于健康的”意思是相同的That book is not healthy reading for a child.对孩子来说那书不是本健康读物。healthy country air有益于健康的农村的空气Regular exercises are healthful.经常运动有益于健康。二.但是healthy还可以作为：1.健康的、健壮的The children look very healthy.孩子们看来很健康。2.看起来健康的His cheeks have healthy glow.他的双颊有着健康的红晕。3.健全的The country"s economy is not very healthy.该国的经济不很景气。

healthy（健康的）的反义词：unhealthy（不健康的）healthy，主要用作形容词，意思是“健康的，健全的；有益于健康的”。双语例句：1、What do I have to do to keep healthy?要保持身体健康我必须得做些什么？2、If you want to be healthy, do some exercise with me.如果你想要变得健康，和我一起做运动吧。

英文原文：healthy英式音标：[u02c8helθu026a] 美式音标：[u02c8hu025blθi]

嗨欧洗

healthy英式读音[u02c8helθi]美式读音[u02c8helθi]healthy，英语单词，主要用作形容词，作形容词时意思是“健康的，健全的；有益于健康的”。短语搭配：healthy diet均衡饮食 ; 健康饮食 ; 健康的饮食 ; 饮食健康healthy granulation健康肉芽形成 ; 康健肉芽形成healthy tea保健茶 ; 健康茶 ; 养生茶 ; 健康的茶双语例句：1、What do I have to do to keep healthy?要保持身体健康我必须得做些什么？2、If you want to be healthy, do some exercise with me.如果你想要变得健康，和我一起做运动吧。3、If you only have one healthy sperm, you would be reluctant to use it for anything but fertilisation.如果你仅有一个健康的精子，除了将它用于受精外，你绝对不愿意将它另作他用。

与其用谐音不如告诉你。/e/发挨的音。跟前面辅音链接就是害中间这个l在原因后面发哦的音。规律就是如此。以后都是如此。所以害哦。最后θ这个其实就是撕的发音。只不过咬着舌头发出来的而已。但你不要舌头也没事。总之是撕的发音。加上后面i。就变成了ABC的C那个音。所以：害哦C。是最接近正确发音的。

[_helθi]。healthy，英语单词，主要用作形容词，作形容词时意思是“健康的，健全的；有益于健康的”。healthydiet均衡饮食；健康饮食；健康的饮食；饮食健康，healthygranulation健康肉芽形成；康健肉芽形成。Ifyouwanttobehealthy，dosomeexercisewithme.如果你想要变得健康，和我一起做运动吧。Ifyouonlyhaveonehealthysperm，youwouldbereluctanttouseitforanythingbutfertilisation.如果你仅有一个健康的精子，除了将它用于受精外，你绝对不愿意将它另作他用。

一、词性读音不同1、health的英式读法是[helθ]；美式读法是[helθ]。作名词意思是健康；医疗保健。2、healthy的英式读法是["helθi]；美式读法是["helθi]。作形容词意思是健康的。二、用法不同1、healthn. (名词)1）health的基本意思既可指人身体的“健康(可好可坏)”,也可指人精神上的“健康”,是不可数名词。2）health有时还可用作祝语,作“祝某人健康”解,可用作不可数名词,也可用作可数名词。2、healthyadj. (形容词)1）healthy作形容词的基本意思是“健康的,健壮的”,指人的身心处于良好的状态,很少生病。引申可作“(事物)兴旺发达,发展良好”解。2）healthy不能用来表示一时的健康,而是指一个长期的状态或过程。三、词汇搭配不同1、health1）affect sb"s health 影响某人的健康2）damage sb"s health 损害某人的健康3）drink health to sb 举杯祝某人健康2、healthy1）feel healthy 感觉身体健康2）grow healthy and strong 茁壮成长3）look healthy 看来身体很好

健康的，孩儿say

fit

问题一：身体健康用英语怎么读 身体健康 be in good health 身体健康 Good health 身体健康 be in good condition 身体健康 physical health 身体健康 physical fitness 问题二：“祝你身体健康”英文怎么说？ I wish you good health意为：祝你身体健康。 Wish you recovered at an early date. 意为：祝你早日康复。 希望我的答能够对你有帮助。 问题三：身体健康的英文翻译 15分 身体健康: 1. in good conition 2. on one"s pins 3. excellent health Examples: 1. 为了维持身体健康，一个人应该吃有益健康的食品，并经常锻炼身体。 In order to maintain physical well being, a person should eat wholesome food and get sufficient exercise. 2. 适当的饮食和运动对身体健康都很重要。 Proper diet and exercise are both important for health. 3. 肌肉发达是身体健康的一个必备条件. Good muscles are one of the prerequisites of physical fitness. 身体健康 rejoice in health 身体健康 be possessed of good health 忽略身体健康 the neglect of health 他身体健康。 He was healthy. 他身体健康。 He is in a good state. 恢复身体健康的严格计划 a rigorous program to restore physical fitness. 他忽视身体健康而自食苦果 neglected his health and paid the penalty. 空气新鲜是身体健康之必需。 Fresh air is fundamental to good health. 新鲜空气和运动能使身体健康。 Fresh air and exercise develop healthy bodies. 身体健康就是有一个强壮健康的身体。 Physical fitness is having a strong healthy body. 问题四：健康用英文怎么写 健康 health ； healthy ； wholesome ； physique ； exuberance 网 络 health； healthy； fitness； Good Health 问题五：健康的用英语怎么说 healthy 问题六：检查身体健康 英文 怎么说 inspect body"s state of health 问题七：祝你身体健康用英语怎么说 5分 I wish you good health 意为：祝你身体健康。 Wish you recovered at an early date. 意为：祝你早日康复福 希望我的答能够对你有帮助。 问题八：“祝你身体健康”英文怎么说？ I wish you good health意为：祝你身体健康。 Wish you recovered at an early date. 意为：祝你早日康复。 希望我的答能够对你有帮助。 问题九：身体健康用英语怎么读 身体健康 be in good health 身体健康 Good health 身体健康 be in good condition 身体健康 physical health 身体健康 physical fitness 问题十：健康的用英语怎么说 healthy

Healthy的意思为：健康；健康的；健壮的；有益健康的；有益于健康的；强健的。一、词义：1、读音：英[u02c8helθi]；美[u02c8helθi]。2、【adj.】：健康的；良好的；健全的；有益的；正常无病的；明智的；无成见的；合意的。3、比较级：healthier。4、最高级：healthiest。二、双语例句：1、A healthy economy is in the best interests of society as a whole.健康发展的经济对社会整体最有利。2、The competition will be healthy,but we needed a kick in the pants.竞赛是有益的，但我们需要一点挫折来激励一下。3、The healthy bloom in her cheeks gave her an aura of innocence.她双颊的健康红润赋予她一种天真无邪的气质。4、In order to keep your marriage healthy,it is important to reconnect as mature individuals.为了保持你们婚姻的幸福，有必要以成熟个人的姿态重新培养感情。5、A healthy skin is a reflection of good health in general.健康的皮肤是整体健康的反映。

because：逼叩死 healthy：黑儿fing（fing读一声）

healthy 英[ˈhelθi] 美[ˈhɛlθi] adj. 健康的; 健全的; 大量的; 有益于健康的; [例句]Most of us need to lead more balanced lives to be healthy and happy我们中大多数人需要过更为平衡的生活，以保持健康和快乐。[其他] 比较级：healthier 最高级：healthiest

”健康的“，形容词，同义词是”fit“

good for health

healthy翻译中文健康的。healthy的意思是：健康的；有益健康的；兴旺发达的；相当多的。。1.健康的；健全的。The country"s economy is not very healthy—该国的经济不很景气。The children look very healthy—孩子们看来很健康。2. 有益于健康的。That book is not healthy reading for a child—对孩子来说那书不是本健康读物。healthy country air—有益于健康的农村的空气。3. 看起来健康的。His cheeks have healthy glow—他的双颊有着健康的红晕。

没有办法插入声音，只能发链接了http://fanyi.baidu.com/?aldtype=85#en/zh/healthier这是音标:英["helθu026au0259r]美["helθu026ar]

音节是读音的基本单位，任何单词的读音，都是分解为一个个音节朗读。 一般的，一个单词中有多少元音节就有多少音节。 英语中的音节若只含有一个元音，就叫做单音节。一个音节叫单音节，两个音节叫双音节，三个音节以上叫多音节。而 healthy是多音节

因为他们很健康用英语说：because they are healthy扩展：healthy：英 [u02c8helθi]；美 [u02c8hu025blθi]释义：adj.健康的；健全的；大量的；有益于健康的短语：healthy life健康人生；healthy food有益健康的食物；keep healthy保持健康healthy lifestyle健康的生活方式；stay healthy保持健康例句：1.Although my uncle is old, he looks very strong and healthy.我的叔叔虽然老了，但他看上去还是很健壮。2.A healthy shoot should form a strong graft.健康的嫩枝可以长成强壮的接穗。3.His inmost thoughts are not healthy.他心灵深处的思想是不健康的。

healthy与healthful的用法区别：1.healthy有两个意思，一是指“健康的”，二是指“有益于健康的”，有时用于比喻义。如：lookatthehealthychildren.你瞧这些健康的孩子。thatbookisnothealthyreadingforchildren.那本书供小孩读不健康。2.healthful在现代英语中通常只表示“有益于健康的”。如：doingmorningexercisesisveryhealthful.做早操对健康很有益。whydon"tyoueatsuchhealthful[healthy]foods?你为什么不吃那些有益于健康的食物?

healthy的比较级：healthierhealthy的最高级：healthiest1. Workplace canteens are offering healthier foods than ever before.单位餐厅以前从没供应过像现在这样健康的饭菜。2. Recent medical studies confirm the efficacy of a healthier lifestyle.最新医学研究证实了较为健康的生活方式的好处。3. Generous spacing gives healthier trees and better crops.足够大的间距能使树木和庄稼长得更茁壮。扩展资料1、单音节形容词和部分双音节词，一般在词尾加-er。2、以字母e结尾的词，在词尾直接加-r。3、重读闭音节词词尾只有一个辅音字母，元音发短音时，双写尾字母，再加er。4、以"辅音字母+y“结尾的双音节词，变”y“为”i“，再加-er。5、多音节词和部分双音节词，在词前加”more“。6、部分形容词和副词的比较级是不规则的，如：good/well-better，bad/badly-worse。7、由“动词+后缀-ing/-ed”构成的形容词，在词前加more构成比较级。如：interesting-more interesting，bored-more bored。8、由“形容词+后缀-ly”构成的副词，在该副词前加more构成比较级。如：slowly-more slowly，happily- more happily。参考资料：百度百科—比较级

less /lɜs/medicine /mɜd(ɪ)s(ɪ)n/healthy/"hɜlθi/secret/"si:krɪt/以上是这些单词的英式读音，如果需要美式读音的可以采纳答案后加追问

heal`thy eat`ing hab`its希望采纳^^

如果read是 过去式，它们的发音就相同，都是发/e/如果read是原形，它们的发音就不同,read/i:/,其它发/e/

前者是名词，后者是形容词。 He has good health. 他身体很好。 He is very healthy. 他很健康。

health 名词词性healthy形容词

1.dragonfruit的读音：英[?dr?ɡ?nfru?t]，美[?dr?ɡ?nfru?t]??释义：火龙果。 2.fruit的用法：fruit是各种水果的总称，如橘子、香蕉、葡萄、苹果、梨等都是fruit，fruit是集合名词。 3.fruit表示各种水果时可用其复数形式fruits，fruit也可指单个的橘子、香蕉等水果，但这种用法不常见。 4.fruit用作比喻，作“成果、结果”解时，可用单数形式，但常用其复数形式。 5.例句：Since?moving?back?to?the?US,?I?admit?that?I?do?miss?eating?fresh?lychees?and?dragon?fruit.自从我搬回美国后，我承认有时候确实会很怀念中国的新鲜荔枝和火龙果。 6.??????????????????扩展资料近义词：pitaya.读音：英[&amp。 7.#39。 8.p?t?j?]，美[&amp。 9.#39。 10.p?t?j?]。 11.??释义：n.火龙果。 12.红龙果。 13.果肉上有许多黑色小籽。 14.用法：pitaya是非专业名词，类似中国的方言。 15.例句：Pitaya?is?a?one?of?the?healthy?fruits?and?has?promising?economic?value.?火龙果是一种具有较高经济价值和保健美容作用的新兴水果。

wealth的读音是：英[welθ]。wealth的读音是：英[welθ]。wealth的详尽释义是n.(名词)财富，财产，钱财，财物，财宝，家私，财丰富，大量，众多，富足，充裕，丰饶，繁荣富有，富裕资源幸福福利富豪（阶级）。wealth【近义词】fortune。一、详尽释义点此查看wealth的详细内容n.(名词)财富，财产，钱财，财物，财宝，家私，财丰富，大量，众多，富足，充裕，丰饶，繁荣富有，富裕资源幸福福利富豪（阶级）二、双解释义n.(名词)[U]财产,财富(possessionofa)largeamountofmoney,property,etc.;riches[S]大量,众多,丰富largeamountornumberofsth;abundanceofsth三、网络解释1.wealth1.富有：最后战略性地将我们的婚姻当一个事业来发展(strategicbusinessdevelopment),迈向健康(healthy),富有(wealth),和充满幸福(intelligent)的婚姻生活.对女人来说,有时候结婚就象是投资一只股票.2.wealth的解释2.财富","财富：其中部分收入,如利息或红利等则来自于财富.财富(wealth)是指人们在某一时点所拥有的资产的货币净值.注意,财富是一个存量,而收入是单位时间中的流量.家庭的财富中包括房屋、字画、汽车等有形资产,也包括现金、储蓄、债券、股票等金融资产.四、例句Healthisbetterthanwealth.【谚】健康胜于财富。He"salwaysflauntinghiswealth.他总是摆阔。Sheisresponsibleforthecharacterpartofthehero"sdevotedmother.她负责这个主人公的忠诚的母亲的角色部分。Hehasgambledawayallhiswealth.他赌博输掉了全部财产。Sheisnottobecomparedwithyouinwealth.她的财产不能与你相比。There"sawealthofbooksinthelibrary.这个图书馆藏书丰富。Jimhasawholewealthofteachingexperience.吉姆具有丰富的教学经验。Hisbosshasawealthofknowledgeaboutinternationaltrade.他的老板有丰富的国际贸易知识。Wealthallowsthemtobeindulgedinabundance.而现在，物质的丰富使人们可以享受大量的这些东西。Shemarriedamanofuntoldwealth.她嫁了一个拥有大量财富的人。五、常见句型用作名词(n.)Nobodyknewhowshehadacquiredherwealth.谁也不知道她的财产是怎么来的。Wealthhadnotbroughtthemhappiness.他们的财富并没有给他们带来幸福。Hiswealthgiveshimagreatpull.他的财富对他极有帮助。Thecountry"swealthisbasedontrade.这个国家的财源主要来自贸易方面。Hewaschargedwithusinghispositiontoaccumulatewealth.他被指控利用地位来敛财。Heisamanofgreatwealth.他是个大款。Thefamilyalwayslivedingreatwealth.那一家过去总是生活阔绰。六、经典引文Therewasnodisplayofwealth;thatcamelater..whenIsawthecrownjewels.出自：E.HeathIsummonedParkson...Howeasily..weacquirethehabitsofwealth.出自：J.Aiken七、词语用法n.(名词)wealth的基本意思是“财产,财富”,指某人拥有的所有财产,可以是物质的,也可以是精神的。wealth还可指“大量,众多,丰富”。wealth作“大量,众多,丰富”解时,一般用单数形式,常用于awealthof短语中,既可用来指“数”,也可用来指“量”。wealth的相关近义词fortune、riches、abundance、quantitywealth的相关临近词wealthy、weald、wealthily、wealthtax、wealthcue、wealthgap、wealthgaps、wealthview、wealthmind、wealthiness、Wealthvalue、WealthEthic点此查看更多关于wealth的详细信息

聚合物是通称一些非常长的分子，当中由结构单位和重覆单位经共价化学键连接一起。 (英文Polymer起源自希腊语中polys即"许多"，meros即部分)。 聚合物与其它分子不同之处在於他们是由许多相同、相似或互补的亚单位重复所组成。这些亚单位或称单体是一些低至中等分子质量的分子，他们经聚合作用的化学反应便可组成聚合物。相似的单体由於有不同的取代基，所以不会是完全相同的。由不同的单体组成的聚合物会有不同的特性例如：溶解度、弹性和强度。譬如在蛋白质里、这些差异使聚合物能形成其独特的生物活跃构象(参见自我组装)。当中相同单体如有非活泼的支链会导致聚合物链形成一无规线团——即根据数学模型所描述的理想链。虽然多数聚合物是有机化合物，并由碳基之单体所组成，但是也有无机聚合物例如，矽橡胶(又称硅树脂)是由交替的硅和氧原子所组成。目录 [隐藏]1 Polymer nomenclature 2 聚合物的物理性质 2.1 Branching 2.2 Stereoregularity 3 Constitution of polymers 3.1 Copolymers 4 Chemical properties of polymers 4.1 Intermolecular forces 4.2 Polymer characterization 5 See also 6 External links [编辑]Polymer nomenclaturePolymers are typically classified according to three main groups:thermoplastics (linear or branched chains) thermosets (crosslinked chains) elastomers Coordination polymers The term polymer covers a large, diverse group of molecules, including substances from proteins to stiff, high-strength Kevlar fibres. For example, the formation of polyethene (also called polyethylene) involves thousands of ethene molecules bonded together to form a straight (or branched) chain of repeating -CH2-CH2- units (with a -CH3 at each terminal):Polymers are often named in terms of the monomer from which they are made. Because it is synthesized from ethene in a process during which all the double bonds in the vinyl monomers are lost, polyethene has the unsaturated structure:If it were named according to its final structure, it would have the alkane designation "polyethane".Because synthetic polymer formation is governed by random assembly from the constituent monomers, polymer chains within a solution or substance are generally not of equal length. This is unlike basic, smaller molecules in which every atom is stoichiometrically accounted for, and each molecule has a set molecular mass. An ensemble of differing chain lengths, often obeying a normal (Gaussian) distribution, occurs because polymer chains terminate during polymerization after random amounts of chain lengthening (propagation).Proteins are polymers of amino acids. Typically, hundreds of the (nominally) twenty different amino acid monomers make up a protein chain, and the sequence of monomers determines its shape and biological function. (There are also shorter oligopeptides which function as hormones.) But there are active regions, surrounded by, as is believed now (Aug 2003), structural regions, whose sole role is to expose the active regions. (There may be more than one on a given protein.) So the exact sequence of amino acids in certain parts of the chains can vary from species to species, and even given mutations within a species, so long as the active sites are properly accessible. Also, whereas the formation of polyethylene occurs spontaneously under the right conditions, the synthesis of biopolymers such as proteins and nucleic acids requires the help of enzyme catalysts, substances that facilitate and accelerate reactions. Unlike synthetic polymers, these biopolymers have exact sequences and lengths. (This does not include the carbohydrates.) Since the 1950s, catalysts have also revolutionised the development of synthetic polymers. By allowing more careful control over polymerization reactions, polymers with new properties, such as the ability to emit coloured light, have been manufactured.[编辑]聚合物的物理性质聚合物的物理性质包括聚合度，分子量分布，结晶度和相转变等，详见高分子物理学。[编辑]BranchingSee also: Branching (chemistry)During the propagation of polymer chains, branching can occur. In free-radical polymerization, this occurs when a chain curls back and bonds to an earlier part of the chain. When this curl breaks, it leaves small chains sprouting from the main carbon backbone. Branched carbon chains cannot line up as close to each other as unbranched chains can. This causes less contact between atoms of different chains, and fewer opportunities for induced or permanent dipoles to occur. A low density results from the chains being further apart. Lower melting points and tensile strengths are evident, because the intermolecular bonds are weaker and require less energy to break.Besides branching, polymers can have other topologies: linear, network (cross-linked 3D structure), IPN (integrated polymer network), comb, or star as well as dendrimer and hyperbranched structures.[编辑]StereoregularityStereoregularity or tacticity describes the isomeric arrangement of functional groups on the backbone of carbon chains. Isotactic chains are defined as having substituent groups aligned in one direction. This enables them to line up close to each other, creating crystalline areas and resulting in highly rigid polymers.In contrast, atactic chains have randomly aligned substituent groups. The chains do not fit together well and the intermolecular forces are low. This leads to a low density and tensile strength, but a high degree of flexibility.Syndiotactic substituent groups alternate regularly in opposite directions. Because of this regularity, syndiotactic chains can position themselves close to each other, though not as close as isotactic polymers. Syndiotactic polymers have better impact strength than isotactic polymers because of the higher flexibility resulting from their weaker intermolecular forces.[编辑]Constitution of polymers[编辑]CopolymersCopolymerization with two or more different monomers results in chains with varied properties. There are twenty amino acid monomers whose sequence results in different shapes and functions of protein chains. Copolymerising ethene with small amounts of 1-hexene (or 4-methyl-1-pentene) is one way to form linear low-density polyethene (LLDPE). (See polyethylene.) The C4 branches resulting from the hexene lower the density and prevent large crystalline regions from forming within the polymer, as they do in HDPE. This means that LLDPE can withstand strong tearing forces while maintaining flexibility.A block copolymer is formed when the reaction is carried out in a stepwise manner, leading to a structure with long sequences or blocks of one monomer alternating with long sequences of the other. There are also graft copolymers, in which entire chains of one kind (e.g., polystyrene) are made to grow out of the sides of chains of another kind (e.g., polybutadiene), resulting in a product that is less brittle and more impact-resistant. Thus, block and graft copolymers can combine the useful properties of both constituents and often behave as quasi-two-phase systems.The following is an example of step-growth polymerization, or condensation polymerization, in which a molecule of water is given off and nylon is formed. The properties of the nylon are determined by the R and R" groups in the monomers used.Image:Con polymer.pngThe first commercially successful, completely synthetic polymer was nylon 6,6, with alkane chains R = 4C (adipic acid) and R" = 6C (hexamethylene diamine). Including the two carboxyl carbons, each monomer donates 6 carbons; hence the name. In naming nylons, the number of carbons from the diamine is given first and the number from the diacid second. Kevlar is an aromatic nylon in which both R and R" are benzene rings.Copolymers illustrate the point that the repeating unit in a polymer, such as a nylon, polyester or polyurethane, is often made up of two (or more) monomers.[编辑]Chemical properties of polymers[编辑]Intermolecular forcesThe attractive forces between polymer chains play a large part in determining a polymer"s properties. Because polymer chains are so long, these interchain forces are amplified far beyond the attractions between conventional molecules. Also, longer chains are more amorphous (randomly oriented). Polymers can be visualised as tangled spaghetti chains - pulling any one spaghetti strand out is a lot harder the more tangled the chains are. These stronger forces typically result in high tensile strength and melting points.The intermolecular forces in polymers are determined by dipoles in the monomer units. Polymers containing amide groups can form hydrogen bonds between adjacent chains; the positive hydrogen atoms in N-H groups of one chain are strongly attracted to the oxygen atoms in C=O groups on another. These strong hydrogen bonds result in, for example, the high tensile strength and melting point of kevlar. Polyesters have dipole-dipole bonding between the oxygen atoms in C=O groups and the hydrogen atoms in H-C groups. Dipole bonding is not as strong as hydrogen bonding, so ethene"s melting point and strength are lower than Kevlar"s, but polyesters have greater flexibility.Ethene, however, has no permanent dipole. The attractive forces between polyethene chains arise from weak van der Waals forces. Molecules can be thought of as being surrounded by a cloud of negative electrons. As two polymer chains approach, their electron clouds repel one another. This has the effect of lowering the electron density on one side of a polymer chain, creating a slight positive dipole on this side. This charge is enough to actually attract the second polymer chain. Van der Waals forces are quite weak, however, so polyethene melts at low temperatures.[编辑]Polymer characterizationThe characterization of a polymer requires several parameters which need to be specified. This is because a polymer actually consists of a statistical distribution of chains of varying lengths, and each chain consists of monomer residues which affect its properties.A variety of lab techniques are used to determine the properties of polymers. Techniques such as wide angle X-ray scattering, small angle X-ray scattering, and small angle neutron scattering are used to determine the crystalline structure of polymers. Gel permeation chromatography is used to determine the number average molecular weight, weight average molecular weight, and polydispersity. FTIR is used to determine composition. Thermal properties such as the glass transition temperature and melting point can be determined by differential scanning calorimetry and dynamic mechanical analysis. Pyrolysis followed by analysis of the fragments is one more technique for determining the possible structure of the polymer.Polymer known as polymer substrate is used for everyday banknotes in Australia, Romania, Papua New Guinea, Samoa, Zambia, Vietnam, New Zealand and a few others, and the material is also used in commemorative notes in some other countries. The process of polymer substrate creation was developed by the Australia CSIRO.

鲁棒性和稳定性的区别是，鲁棒性即稳健性，外延和内涵不一样，稳定性只做本身特性的描述。鲁棒性原是统计学中的一个专门术语，20世纪70年代初开始在控制理论的研究中流行起来，用以表征控制系统对特性或参数扰动的不敏感性。鉴于中文鲁棒性的词义不易被理解，robustness又被翻译成了语义更加易懂的抗变换性，抗变换性和鲁棒性在译文中经常互相通用 。稳定性是指使用者对产品的满意程度或对企业的信赖程度。而这种满意程度或信赖程度是从主观上来判定的。为了对产品可靠性做出具体和定量的判断，可将产品可靠性可以定义为在规定的条件下和规定的时间内，元器件(产品)，设备或者系统稳定完成功能的程度或性质。例如，汽车在使用过程中，当某个零件发生了故障，经过修理后仍然能够继续驾驶。所谓鲁棒性，是指控制系统在一定（结构，大小）的参数摄动下，维持其它某些性能的特性。而稳定性，是指控制系统在使它偏离平衡状态的扰动作用消失后，返回原来平衡状态的能力。

　　【健壮性】　　健壮性又称鲁棒性，是指软件对于规范要求以外的输入情况的处理能力。　　所谓健壮的系统是指对于规范要求以外的输入能够判断出这个输入不符合规范要求，并能有合理的处理方式。　　另外健壮性有时也和容错性，可移植性，正确性有交叉的地方。　　比如，一个软件可以从错误的输入推断出正确合理的输入，这属于容错性量度标准，但是也可以认为这个软件是健壮的。　　一个软件可以正确地运行在不同环境下，则认为软件可移植性高，也可以叫，软件在不同平台下是健壮的。　　一个软件能够检测自己内部的设计或者编码错误，并得到正确的执行结果，这是软件的正确性标准，但是也可以说，软件有内部的保护机制，是模块级健壮的。　　软件健壮性是一个比较模糊的概念，但是却是非常重要的软件外部量度标准。软件设计的健壮与否直接反应了分析设计和编码人员的水平。即所谓的高手写的程序不容易死。　　【鲁棒性】　　鲁棒是Robust的音译，也就是健壮和强壮的意思。它是在异常和危险情况下系统生存的关键。比如说，计算机软件在输入错误、磁盘故障、网络过载或有意攻击情况下，能否不死机、不崩溃，就是该软件的鲁棒性。所谓“鲁棒性”，是指控制系统在一定（结构，大小）的参数摄动下，维持其它某些性能的特性。根据对性能的不同定义，可分为稳定鲁棒性和性能鲁棒性。以闭环系统的鲁棒性作为目标设计得到的固定控制器称为鲁棒控制器。

阿卡贝拉”(A Cappella)是什么？（一） “人”本身就是世界上最好、最精致的发声体，人声是世界上最美丽的声音，用最好的发声器及最美丽的声音所创造出来的音乐必定是最好的音乐！“阿卡贝拉”(A Cappella)是什么？很多音乐老师会说：“那是中世纪教堂中所发展出来无伴奏人声合唱音乐，是古典音乐的一种。”这样解释只有部分正确，A Cappella这个意大利文的意义是：以教堂的方式（唱），即“in the style of the chapel”。从十三、四世纪以来教会就以清唱方式（最多加上管风琴）主导着合唱音乐，而很多人只注意到人声的美丽，且无乐器伴奏，便非常简单的以“无伴奏”(unaccompanied)一词来解释A Cappella，其实 unaccompanied的正确的翻译是“无伴”，而人声可以做很丰富的伴奏，因此，用“无伴奏”来说明或解释A Cappella极不恰当。不论如何，对于世界各地的人们而言，阿卡贝拉的意义可定义为：仅运用人声所创造出来的音乐(music created with nothing more than the hun voice)。至于广义的“人声”则可定义为：人类身体所能创造出来的声音。阿卡贝拉(A Cappella)是一种不依赖乐器的人声音乐。而此种阿卡贝拉型体，我们称之为“阿卡贝拉团”(A Cappella group)，而演唱流行、爵士、摇滚甚至hip-hop等比较现代曲的团体，我们称之为“阿卡贝拉人声乐团”(A Cappella ocal Band---AB)，也可简称为“人声乐团”(ocal Band---B)。至于我们所谓的“重唱”一词似与“重奏”有类似的意义，比较趋向古典、宗教、民谣或传统之音乐型态，其定义之基础在于“重”字，即以表演人数/声部来做说明，两个（含）不同声部以上的合唱就叫重唱，与阿卡贝拉以人声为主的定义基础不同。因此吾人不宜以“无伴”、“无伴奏”或“重唱”等名词来解释“阿卡贝拉”。阿卡贝拉不是一种特别的音乐型式，它只是一种音乐表达对器乐的选择~~阿卡贝拉可以在世界各民族文化的传统音乐中发现。说到这里，大家会问：“阿卡贝拉”既是中世纪教堂的东西，跟现在的人声音乐又扯得上什么关系？“阿卡贝拉”(A Cappella)是什么？（二）话说“阿卡贝拉”走到二十世纪初期，走到美国，出现了所谓的“理发店四重唱”(Barbershop uartet)，在流行乐的范畴中占有极重要的一块。以四声部在同一时间唱同样词，以内含主旋律之对位方式表现，架构了当时的阿卡贝拉重唱表演平台及流行乐团生态。到了50年代，出现了所谓doo-wop演唱方式，以主唱者(lead singer)为聚焦，其它和声部分则以简单的三及重复合声旋律或以单音节声音或器乐摹拟来配合主唱者。同时期在英国也孕酿出更新的流行环境，加入主流场，即使“披头四(The Beatles)”乐团也多少受到影响。到现在，“理发店四重唱”在美国仍然具有举足轻重之地位。另外，人声团体如“史温戈手(Swingle Singers)”、“国王手(The King"s Singers)”及“香蒂克莉(Chanticleer)”等团体也从古典(Classical)、民谣(Folk)及传统(Traditional)音乐出发，开始绽放光芒。“阿卡贝拉”走到二十世纪末期，于90年代更产生革命性新风潮。人们发现：其实人类本身所能发出的声音就是最美丽的声音，而人的声音竟然还有很多很多尚待的部分！于是音乐家们返回人类音乐的最初源头----人声，重新审视它的潜能，并要求者声音的无限可能，于是它的多样性及丰富性造就了新和谐音乐(harmony music)及人声乐团(A Cappella ocal Band简称AB)的出现，吾人简称之为“人声乐团”(与一般使用器乐之流行音乐乐团有别)。如上所述，西方音乐创作人对于音乐之创作观念受到“阿卡贝拉”的演变所影响，他们已了解“阿卡贝拉”是一种“乐器编奏法”(instrumentation)，它必须回归作、编曲之正确运用，简言之：将人声定位为音乐工具来做音乐而已，仅是如此，就足以解放人声音乐创作的，走出死胡同。试想：有这么多的（人声）乐器可以运用，只要稍加训练，什么音乐做不出来？于是Take 6乐团将教堂圣乐混合R&B，Swingle Singers跨古典与现代丰富舞台表演，Zap Ma乐团将乡土音乐混合世界各地民谣，The King"s Singers将古典结合POP，The Nylons乐团将doo-wop结合POP，The Real Group由传统走上爵士……就这样，人声世界就开始多姿多彩起来！“现代阿卡贝拉”于焉产生，并将成为这一代人声音乐(ocal Music)的追求目标，流行音乐也从此开始受到冲击。“阿卡贝拉”(A Cappella)是什么？（三）在这些大杂烩中，从90年代中期开始，乐团就在技巧运用发展上产生了“人声敲击乐(ocal Percussion)”，这种团体就是有本事光靠人声就能创造出与一般流行乐团运用爵士鼓所创造的相同的音乐效果，不可思议吧！人声敲击乐及人声bass的结合，筑成紧密且前卫的音乐平台，在这个平台上交织着其它各种人声乐器旋律，摹拟吉他、喇叭、大小提琴、合成音响、还有很多自然界动物及无法称呼的声音等之交互（人声）演奏，接着再加上领唱lead主旋律，就这样，一场细致而完整的人声流行乐团所端出的音乐飨宴，就足以让你high上一整晚！而整个乐团及者只需在口袋里塞个麦克风，便可走唱世界各地，完全不靠乐器。另外，在持续发展上，我们也看到了所谓“节奏盒(Beat Box)”的出现，让节奏音响人声的更向前跨越一大步。在90年代末期，阿卡贝拉乐团更进一步将录音室里的音控，运用在现场做音效演出。至于一些舞台元素如：舞蹈、肢体语言、走位、表情、说话、剧情、幽默、隐喻、带动教唱、观众互动等等，则已经成为阿卡贝拉除了声音（音乐）以外，吸引观众最重要的表演内涵，也成为阿卡贝拉者在二十一世纪所积极探索的更宽广的领域。阿卡贝拉永远在进化中！阿卡贝拉团有其特殊之处，并不是一个合唱团偶尔唱几首阿卡贝拉曲子就可称之为阿卡贝拉团，一定要是专以阿卡贝拉曲为其主要表演内容的团体，我们才能说它是阿卡贝拉团。至于阿卡贝拉团的人数则并未有特殊限制，一般业余团体的人数较多，甚至有达到人，学生也有多到二十余人的团体，但一般而言不论是业余或是学生团，一个声部大致有1~3人。至于职业阿卡贝拉团则是以3~7人较为常见（尤其4~6人最多），这是因为在职业水准的要求之下，精致的音乐不需人多，每个声部(part)只需一人即可达成，且根据丛林法则，演出团体小，其职业生涯较可持久，演出团体大，其背后的财务支撑也较困难。至于您如果要问音乐奇才，具有四个八度音域的Bobby McFerrin的单人演唱(one n/mouth band)是否归类为阿卡贝拉，那答案绝对是肯定的！