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蝴蝶定理的英文是Butterfly Theorem
蝴蝶定理的英文是Butterfly Theorem,蝴蝶定理是古典欧氏平面几何的最精彩的结果之一。这个命题最早
中文名称
外文名称 只蝴蝶。这个定理的证法多得不胜枚举,至今仍然被数学热爱者研究,在考试中时有出现各种变形。 基本信息 蝴蝶定理 Butterfly Theorem
目录
1 定理简介
2 定理内容
1 定理简介
蝴蝶定理(Butterfly theorem),是古典欧式平面几何的最精彩的结果之一。这个命题最早出现在1815年,而的证法多得不胜枚举,至今仍然被数学热爱者研究,在考试中时有出现各种变形。这个命题最早作为一个征解问国一个自学成才的中学数学教师W.G.霍纳(他发明了多项式方程近似根的霍纳法)给出了第一个证明,完全是初Bland)在《几何问题》(1827年)一书中给出。最为简洁的证法是射影几何的证法,由英国的J·开世在"A Se商务印书馆 1956 )给出,只有一句话,用的是线束的交比。1981年,Crux杂志刊登了K.萨蒂亚纳拉亚纳(Ke上是射影几何中一个定理的特殊情况,有多种推广:M,作为圆内弦是不必要的,可以移到圆外。圆可以改为任向线段的比例式,称为“坎迪定理”, 不为中点时满足: ,这对2,3均成立。
2 定理内容
蝴蝶定理是古典欧式平面几何的最精彩的结果之一。蝴蝶定理最先是作为一个征求证明的问题。由于其几何 定理内容:圆O中的弦PQ的中点M,过点M任作两弦AB,CD,弦AD与BC分别交PQ于X,Y,则M为XY之
蝴蝶定理出现过许多优美奇特的解法,其中最早的,
它给予出的是面积证法,其中应用了面积公式:S=1/2 BCSINA。
这里介绍一种较为简便的初等数学证法。
证明:过圆心O作AD与BC垂线,垂足为S、T,连接OX,OY,OM。SM。MT。 ∵△AMD∽△CMB,且SD=1/2AD,BT=1/2BC
∴DS/BT=DM/BM
又∵∠D=∠B
∴△MSD∽△MTB,∠MSD=∠MTB
∴∠MSX=∠MTY;
又∵O,S,X,M与O,T,Y,M均是四点共圆,
∴∠XOM=∠YOM
∵OM⊥PQ
∴XM=YM 应首推霍纳在1815年所
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创建者:jzs201109 创建时间:2013-06-13 汁缘mesi 贡献排名: 我有我姿态
自然卷爱糖分
kilameng 小闸蟹_201
历史版本 热门词条
《爸爸去哪儿》第二季 李小冉 陈思诚 佩普基诺 王文元 李承铉 周鸿祎 吴镇宇 巴西世界杯 令政策
The Butterfly Effect 蝴蝶效应 英语作文汉语对照
The Butterfly Effect 蝴蝶效应
First listen and then answer the following question.
Why do small errors make it impossible to predict the weather system with a high degree of accuracy?
Beyond two or three days, the world's best weather forecasts are
speculative, and beyond six or seven they are worthless.
The Butterfly Effect is the reason. For small pieces of weather -- and to a global forecaster, small can mean thunderstorms and blizzards -- any prediction deteriorates rapidly. Errors and uncertainties multiply, cascading upward through a chain of turbulent features, from dust devils and squalls up to continent-size eddies that only satellites can see.
The modern weather models work with a grid of points of the order of sixty miles apart, and even so, some starting data has to guessed, since ground stations and satellites cannot see everywhere. But suppose the earth could be covered with sensors spaced one foot apart, rising at one-foot intervals all the way to the top of the atmosphere. Suppose every sensor gives perfectly
accurate readings of temperature, pressure, humidity, and any other quantity a meteorologist would want. Precisely at noon an infinitely powerful computer takes all the data and calculates what will happen at each point at 12.01, then 1202, then 12.03...
The computer will still be unable to predict whether Princeton, New Jersey, will have sun or rain on a day one month away. At noon the spaces between the sensors will hide fluctuations that the computer will not know about, tiny deviations from the average. By 12.01, those fluctuations will already have created small errors one foot away. Soon the errors will have multiplied to the ten-foot scale, and so on up to the size of the globe.
JAMES GLEICK, Chaos
New words and expressions 生词和短语
forecast
n. 预报
speculative
adj. 推测的
blizzard
n. 暴风雪
deteriorate
v. 变坏
multiply
v. 增加
cascade
v. 瀑布似地落下
turbulent
adj. 狂暴的
dust devil
小尘暴,尘旋风
squall
n. 暴风
eddy
n. 旋涡
grid
n. 坐标方格
sensor
n. 传感器
humidity
n. 温度
meteorologist
n. 气象学家
Princeton
n. 普林斯顿(美国城市名)
New Jersey
n. 新泽西(美国州名)
fluctuation
n. 起伏,波动
deviation
n. 偏差
参考译文
世界上最好的两三天以上的天气预报具有很强的猜测性,如果超过六七天,天气预报就没有了任何价值。
原因是蝴蝶效应。对于小片的恶劣天气 -- 对一个全球性的气象预报员来说,“小”可以意味着雷暴雨和暴风雪 -- 任何预测的质量会很快下降。错误和不可靠性上升,接踵而来的是一系列湍流的徵状,从小尘暴和暴风发展到只有卫星上可以看到的席卷整块大陆的旋涡。
现代气象模型以一个坐标图来显示,图中每个点大约是间隔60英里。既使是这样,有些开始时的资料也不得不依靠推测,因为地面工作站和卫星不可能看到地球上的每一个地方。假设地球上可以布满传感器,每个相隔1英尺,并按1英尺的间隔从地面一直排列到大气层的顶端。再假定每个传感器都极极端准确地读出了温度、气压、温度和气象学家需要的任何其他数据。在正午时分,一个功能巨大的计算机搜集了所有的资料,并算出在每一个点上12:01、12:02、12:03时可能出现的情况。
计算机无法推断出1个月以后的某一天,新泽西州的普林斯顿究竟是晴天还是雨天。正午时分,传感器之间的距离会掩盖计算机无法知道的波动、任何偏平均值的变化。到12:01时,那些波动就已经会在1英尺远的地方造成偏差。很快这种偏差会增加到尺10英的范围,如此等等,一直到全球的范围
英文诗歌:蝴蝶
As love falls down from the sky,
It lands on the wings of a butterfly.
The butterfly sings it's songs and rhymes,
And flies through the air, No concept of time.
It is the messenger of patience and change,
From flower to flower, it's odd and it's strange.
The butterfly can transform it's world.
And give way to new beginnings, unfurled,
It is the keeper of transformation,
And flies on faith and imagination.
The butterfly as no fear of change,
It bravely escapes it's homemade cage.
To change, it knows is necessary,{三年级英语作文butterfly}.
For all the burdens we need not carry.
The butterfly soars, and merrily sings,
For, without change, it could never grow wings.
【参考译文】
爱自天空降落,
落在蝴蝶的翅上。
蝴蝶歌之咏之,
翩然而飞,乐而忘时。
它是耐心和蜕变的信使,
在花丛中飞舞,甚是奇异。
蝴蝶能自我蜕变,
并臣服于新生,毫无保留。{三年级英语作文butterfly}.{三年级英语作文butterfly}.
它守护着蜕变,
飞越想象与信念。
蝴蝶不惧蜕变,
勇敢逃离自缚之茧。
它知道必须要蜕变,
我们无须背负所有的重担。
蝴蝶展翅翱翔,欢快歌唱,
因为,不蜕变,就无法长出翅膀。
更多英语学习方法:企业英语培训
经典的英文语句,I’LL,MAKE,MY,JOY,LIKE,THIS,SMALL,BUTTERFLY
篇一:一些经典的英文语句
一些
经典的英文语句
never trouble
trouble till trouble troubles you.
麻烦没来找你,就
别去自找麻烦。
never judge people by their appearance.
永远不要以貌取人
laugh,and the
world laugh with you;weep,and you weep alone
笑吧,全世界都陪
你笑;哭吧,你一个人哭。{三年级英语作文butterfly}.
the quick brown
fox jumps over a lazy dog.
那只敏捷的棕色狐
狸跳过了一只懒惰的狗。
please forgive me for falling in love with you.forgive me for loving you with all
my heart.forgive me for never wanting to be apart. sandra robbins heaton 请原谅
我爱上你;原谅我用全部的身心爱你;原谅我永不愿与你分离。
it doesn’t
matterthat you are not here in person as long as you are here in my heart. 就算
你不在这里也没关系,因为你在我心里。
i’ll make my joy
like this small butterfly.
我会和这小蝴蝶一
样找寻快乐。
hope is a good thing and maybe the best of things. and no good thing ever dies. 希
望是一个好东西,也许是最好的,好东西是不会消亡的。
行路有良伴就是捷
径。
forever friend
gets you through the hard times, the sad times, and the confused times.
真正的朋友会与你
一同度过困难、伤心和烦恼的时刻。
everymanshouldmarryafterall,happinessisnottheonlythinginlife
再快乐的单身汉迟
早也会结婚,幸福不是永久的嘛。
behindeverysuccessfulman,thereisamanandbehindeveryunsuccessfulman,therearetwo
每个成功男人的背
后,都有一个女人。每个不成功男人的背后,都有两个。
a friend walks in
when the rest of the world walks out.
别人都走开的时候,
朋友仍与你在一起。
you know some birds are not meant to be caged, their feathers are just too bright.
你知道,有些鸟儿是注定不会被关在牢笼里的,它们的每一片羽毛都闪耀着自由的光辉。
we must hang
together, or we’ll be hanged separately.
我们必须团结在一
起,否则我们将被一个个绞死。
was it a bar or a bat i saw?
我看到的是酒吧还
是蝙蝠?
two star-crossed lovers in perfect harmony. just give me a chance and you will agree.i
was meant for you.and you were meant for me. daniel lazarus garci
两个命运多舛的情
人如此和谐地在一起,只要给我一线希望,你终将答应。我为你而生,你因我而存在。
to the world you may be one person, but to one person you may be the world. 对于
世界而言,你是一个人;但是对于某个人,你是他的整个世界。
there is something inside ,that they can’t get to , that they can’t touch. that’
s yours. 那是一种内在的东西, 他们到达不了,也无法触及的,那是你的。
篇二:美丽的英语句子
im
just folk.i have mood swings.
我只是个平凡人,我也有我的小情绪
if one day, you into my heart, youll cry because there is full of you. if one day,
i went into your heart, i also will cry, because there is no me.
如果有一天,你走进我心里,你会哭,因为里面满满的都是你,如果有一天,我走进你心里,
我也会哭,因为那里没有我。
if you love somebody, let them go. if they return, they were always yours. if they
dont, they never were.
如果你爱一个人,让他走,如果他回来了,他就是你的,如果他走了,那么他从来就不属于
你。
love should be like wine. the longer you keep it, the stronger it will taste.
爱似美酒,日久闻香。
no matter the ending is perfect or not, you cannot disappear from my world.
我的世界不允许你的消失,不管结局是否完美
love is a carefully designed lie.
爱情是精心编织的谎言。
promises are often like the butterfly, which disappear after beautiful hover.
承诺
常常很像蝴蝶,美丽的飞盘旋然后不见
if you are already walking on thin ice,you might as well dance.
倘若你已经步履薄冰,不妨翩翩起舞
happiness is a warm person looking for life; and im still waiting for you, but you
have forgotten had been here; love so short, forgetting is so long.
幸福,就是找一个温暖的人过一辈子;而我还在原地等你,你却已经忘记曾来过这里;爱那
么短,遗忘那么长
if you weeped for the missing sunset,you would miss all the shining stars
如果你为错过夕阳而哭泣,那么你就要错过群星了
if we can only encounter each other rather than stay with each other,then i wish we
had never encountered .
如果只是遇见,不能停留,不如不遇见
i would like weeping with the smile rather than repenting with the cry,when my heart
is broken ,is it needed to fix?
宁愿笑着流泪,也不哭着说后悔。心碎了,还需再补吗
there are no trails of the wings in the sky, while the birds has flied away.
天空没有鸟的痕迹,但我已飞过
when a cigarette falls in love with a match,it is destined to be hurt
当香烟爱上火柴时,就注定受到伤害
within you i lose myself, without you i find myself wanting to be lost again
有了你,我迷失了
自我。失去你,我多么希望自己再度迷失。
never ignore a person who loves you, cares for you, misses you. because one day, you
might wake up from you lost the moon while counting the stars
不要忽视那个爱你的人,关心你的、想念你的人。因为有一天你会发现当你追逐星星的时候
却丢失了月亮
be yourself, dont change for anyone. if they dont like you at your worst, then they
dont deserve you at your best
勇敢的做自己,不要为任何人而改变。如果他们不能接受最差的你,也不配拥有最好的你
love a person, love a habit.
爱上一个人,等于爱上了一种习惯
without you every day is a rainy day. i miss you
没有你的日子里阴雨连绵。我想念着你。
one day i passed, one day i missed, one day left, i gotta grasp it.
一天路过,一天错过,还有一天,好好把握
the god is equal to everyone. when he gives you one thing, he’ll take away another
from you. we always see what he takes away, but not see what he gives us
上帝对每个人都是平等的。当他给予你一样东西的同时也带走了另一样东西。我们总是看到
他带走了什么,却没发现他给予了我们什么
with his saying sorry for being difficult for herself.{三年级英语作文butterfly}.
跟自己说声对不起,因为曾经为了别人难为了自己
篇三:some classical english sentence一些经典的英文语句
some
classical english sentence一些经典的英文语句
never trouble
trouble till trouble troubles you.
麻烦没来找你,就
别去自找麻烦。
never judge
people by their appearance.
永远不要以貌取人
laugh,and the
world laugh with you;weep,and you weep alone 笑吧,全世界都陪你笑;哭吧,你一个
人哭。
the quick brown
fox jumps over a lazy dog.
那只敏捷的棕色狐
狸跳过了一只懒惰的狗。
please forgive me
for falling in love with you.forgive me for loving you with all my heart.forgive me
for never wanting to be apart. sandra robbins heaton
请原谅我爱上你;
原谅我用全部的身心爱你;原谅我永不愿与你分离。
it doesnt
matterthat you are not here in person as long as you are here in my heart.
就算你不在这里也
没关系,因为你在我心里。
ill make my joy
like this small butterfly.
我会和这小蝴蝶一
样找寻快乐。
hope is a good
thing and maybe the best of things. and no good thing ever dies.
希望是一个好东西,
也许是最好的,好东西是不会消亡的。
行路有良伴就是捷
径。 forever friend gets you through the hard times, the sad times, and the confused
times.
真正的朋友会与你
一同度过困难、伤心和烦恼的时刻。
everymanshouldmarryafterall,happinessisnottheonlythinginlife 再快乐的单身汉迟
早也会结婚,幸福不是永久的嘛。
you know some
birds are not meant to be caged, their feathers are just too bright.
你知道,有些鸟儿
英语故事新三只蝴蝶
Three butterflies
There are three butterflies in the garden. One is red, one is yellow, and the last is white. They're playing and dancing in the garden all day. They're very happy.
Suddenly, it rains! They fly to the red flowers and ask:“We're so cold. Can we hide under your leaves?”The red flowers answer:“Red butterfly, please come in. The others go way!”Three butterflies say together:“We're good friends, we must stay together.”It's raining harder. They fly to the yellow flowers and ask:“We're so cold. Can we hide under your leaves?”The yellow flowers answer:“Yellow butterfly, please come in. The others go way!”Three butterflies say together:“We're good friends, we must stay together.”It's raining harder and harder. They fly to the white flowers and ask:“We're so cold. Can we hide under your leaves?”The white flowers answer:“White butterfly, please come in. The others go way!”Three butterfly say together:“We're good friends, we must stay together.”They fly under the rain. They are cold and afraid. But they don't want to leave their friends.
Just then, the sun comes out. He smiles and stops the rain. It’s sunny now. The butterflies dance and play in the garden. They are happy!
三年级英语练习题
一、写出相邻的字母。
1. ______ B b ______ 2. ______ E e _______ 3. ______T t_____
4._____ V v ______ 5. ______ H h _____ 6. _____ Y y ______
7. _____ L l _____ 8. _____ Qq _____ 9. _____ Kk_____
10. _____ Gg _____
二、将单词按正确顺序连成句子并写下来。 1. is this Who ?
2. Lisa my It’s , sister . 3. too Is this your , brother ? 4. are you How ?
5. fine thanks , I’m .
三、选词补全句子。
1. This is _____ (me , my).
2. Is this your brother _____(too ,to)? No, it’s ______(no, not).
3. How are you ? I’m fine ,________(thank, thanks).
4. Who’s _____(she , he )? This is my friend ,. Peter.
5. Who’s this ? _____(Its , It’s) my sister.
四.选词补全句子 (20)
1. What’s your name? - ______(Your, My) name is Tutu.
2. What’s your name? – I ______ (am, is) Lisa.
3. ________ in. (Come, Go)
4. Go _______ .(here, out)
5. Good night, Tutu. –Good __________,(night, morning) Lisa.
1
一、把下列单词不同类一项找出来
( )1. A. ill B. sad C. mouse
( )2. A.test B. stomach ache C.headache
( )3. A. clever B.have C.has
( )4. A. train driver B.bus driver C.shorts
( )5.A.policeman B.winner C.doctor
( )6.A.taxi .B.horse C.camel
( )7.A.teacher B.chips C.cakes
二、选择正确的句子补全对话 。
Jack:Hi,______________.
Tutu: Hi, my name’s Tutu. What’s your name?
Jack: _________________
Mom: Jack, Jack! Come here!
Jack: _________________. Good night, Tutu.
Tutu: _______________________.
A. Good night, Jack.
B. What’s your name?
C. I’m Jack.
D. OK, Mom.
三,选择合适的词填空。
morning see am How door
1.( )are you? 2. Open the ( ). 3.
4. Good ( ) ,Miss Fang. 5.Here I ( )!
( ) a rubber. 2 I
一、选择合适的答案。
()1、当有人帮助你时,你应该说: A.Good morning. B.Thank you. C.Goodbye. ()2、当别人对你说“How are you?”时,你应该说:
A.Good morning. B.Fine,thanks.
()3、 Xiao Qiang. A.I am. B.Thank you. C.Fine. ()4、A:Hello,I'm Kitty. B: .
A.I'm Kitty. B.Hi,I'm Ling Ling. C.Bye-bye.
()5、A.Hello! B: . A.Hi! B.Morning! C.I'm Sam.
二、你能把下面句子按先后顺序排成一段话吗?相信你一定能。
( )Good morning, how are you?
( ) Goodbye.
( ) Fine, thank you. How are you?
( )Good morning.
( ) I'm fine. Goodbye.
三、选择合适的一项。 ( )1.I'm girl. A./ B.a C. An ( ) 2.He tall. A.am B.is C. Are ( ) 3. you are. A.here B.Here C.There ( ) 4. She is my . A.brother B.father C.mother ( ) 5.He's little brother. A. my B.you C. She ( ) 6. Happy birthday to . A.you B.your C. yours ( )7. Is it apple? A. / B. a C. an
( )8. Two tall teachers the rain. A. in B. at C. on 3
( ) 9. is it ? A rubber. A.Who B.How C.What ( )10. I'm nine. She's two. She's my .
A.big sister B. big brother C. little sister ( )11.Who's she? She's my . A.father B.brother C. mother ( )12. the blackboard, please. A.Open B.Close C.Clean
( )13. Hello, I'm a mouse . tail is long. A.My B.I C.me ( )14. . Thank you.
A.Here you are. B.Who are you? C. How are you? ( )15.Is it umbrella? A. a B. an C. the
( )16. Are you Alice? Yes ,I . A. am B. is C. are
四、连词成句 1. you Are Mary ? 2. friends good We are . 3. you to birthday Happy ! 4. a Is book it ?
五、读一读,帮下列句子找到自己的好朋友。
( ) 1. A cake, Ben?
( )2. Happy birthday.
( )3. Is Sam tall?
( ) 4. Is it a desk?
( ) 5. Who is she?
A. Yes ,please. B.Yes C. Thank you. D. She is my mother. E. No ,it is a box
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一、根据情况选择合适的一项。
1、早上见到老师,你要问好,你应说: A.Hello. B.Good morning. C.Goodbye.
2、你们班里来了一位新同学,你想知道对方的名字,怎么问?
A. How are you? B.Bye-bye. C.What's your name?
3.当你想了解对方的身体状况时,怎么说:
A.How are you? B.Bye-bye.C.What's your name?
4.当你和别人道别时,你们要说:
A.How are you? B.Goodbye. C.What's your name?
5.当别人问你的名字时,你应该怎么回答?
A.Hello. B.Good morning. C.I'm Xiao Wei.
6.请小朋友把窗子擦干净,可以说: A.Close the window,please.
B.Open the window,please. C.Clean the window,please.
7、请小朋友吃桔子,可以说:
A. An orange,please. B.It's an orange. C.Is it an orange?
8、当你想告诉别人我九岁时,你应说:
A.I'm nine. B.I'm eight. C. I'm seven.
二、小嘴读一读,帮下列句子找到自己的好朋友。
( )1. What colour is it? ( ) 2. Is it a ball?
( ) 3. Is your triangle blue?
( ) 4. What shape is this?
( ) 5. Is this a classroom?
A. Yes ,it is. B. No ,it's a library. C.. It's black.
D. It's a circle. E. No , it's yellow.
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