D-mesons in dense nuclear matter

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501151v 1 17 J a n 2005

EPJ manuscript No.

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D-mesons in dense nuclear matter

L.Tol′o s 1,J.Scha?ner-Bielich 1and A.Mishra 2

1

Institut f¨u r Theoretische Physik &FIAS.J.W.Goethe-Universit¨a t.Postfach 111932.60054Frankfurt am Main,Germany 2

Department of Physics,I.I.T.Delhi,New Delhi -110016,India

Received:date /Revised version:date

Abstract.The D-meson properties in dense nuclear matter are studied.The D-meson spectral density is obtained within the framework of a coupled-channel self-consistent calculation assuming,as bare meson-baryon interaction,a separable potential.The Λc (2593)resonance is generated dynamically in our coupled-channel model.The medium modi?cations of the D-meson properties due to Pauli blocking and the dressing of D-mesons,nucleons and pions are also studied.We conclude that the self-consistent coupled-channel process reduces the in-medium e?ects on the D-meson compared to previous literature which do not considered the coupled-channel structure.PACS.

14.40.Lb,14.20.Gk,21.65+f

1Introduction

The study of the properties of hadrons in hot and dense matter has become a subject of lively interest over the last years in connection with heavy-ion experiments [1]as well as due to implications for astrophysical phenomena.In particular,a strong e?ort has been invested in under-standing the properties of antikaons due to the possibility of kaon condensation in neutron stars [2].On the other hand,K ±production from nuclear collisions at GSI has shown that in-medium properties of kaons have been seen in di?erent experimental observables like collective ?ow

[3].Medium modi?cations of D (ˉD)

mesons,which show analogy with ˉK

(K)coming from the replacement of the s quark (s antiquark)by c quark (c antiquark),have also become a matter of recent interest.The study of medium modi?cations of the D-meson could have important conse-quences for open-charm enhancement in nucleus -nucleus collisions [4]as well as for J/Ψsuppression [5].

The NA50Collaboration [6]has observed an enhance-ment of dimuons in Pb+Pb collisions which has been ten-tatively attributed to an open-charm enhancement in nu-cleus -nucleus collisions relative to proton -nucleus re-actions at the same

√Λ2

C i,j Θ(Λ?k)Θ(Λ?k ′),

(1)

where g and Λare the coupling constant and cuto?,re-spectively.These two parameters will be determined by

2L.Tol′o s,J.Scha?ner-Bielich,A.Mishra:D-mesons in dense nuclear matter

?xing the position and the width of the Λc (2593)reso-nance.For the interaction matrix

C

ij ,

we use the result de-rived from SU(3)?avor symmetry [14].We are,therefore,

confronted with a coupled-channel problem since this in-teraction allows for the transition from DN to other chan-nels,namely,πΛc ,πΣc ,ηΛc and ηΣc ,all having charm c =1.The G-matrix is then given by

M 1B 1|G (?)|M 2B 2 = M 1B 1|V |M 2B 2 + M 3B 3

M 1B 1|V |M 3B 3

Q M 3B 3

k 2D +m 2D U D (k D

,ω).(4)

This self-energy can then be used to determine the D-meson single-particle propagator

D D (k D ,ω)=

1

m 2D +k 2D U D (k D ,ω)

,(5)

and the corresponding spectral density

S D (k D ,ω)=?

1

dm

∝|T I =0

πΣc →πΣc

|2p CM (7)

where p CM is the πΣc relative momentum and T I =0

πΣ

c →πΣc

is the isospin zero component of the on-shell s-wave T-matrix for the πΣc channel.Our coupled-channel calcula-tion generates dynamically the Λc (2593)resonance.The

position (2593.9±2MeV)and width (Γ=3.6+2.0

?1.3MeV)are obtained for a given set of coupling constants and cut-o?s running from 0.8GeV to 1.4GeV.

Once the position and width of the Λc (2593)resonance are reproduced dynamically,we study the e?ect of the dif-ferent medium modi?cations on the resonance.In Fig.2we display the real and imaginary parts of the s-wave DN am-plitude for I =0and I =1within di?erent approaches:T-matrix calculation (dotted lines),self-consistent calcula-tion for the D-meson at ρ=ρ0(solid lines),where ρ0is the nuclear saturation density,and self-consistent calculation for the D-meson including the dressing of nucleons and the pion self-energy at ρ=ρ0(long-dashed lines).When the nucleons and pions are dressed in the self-consistent process,the picture depicted is completely di?erent to the case when only D-mesons are dressed self-consistently.In fact,the DN interaction in I =0becomes smoother in the region of energies where the Λc (2593)resonance was generated when only the D-mesons were dressed.Further-more,we observe one structure around 2.5GeV below the πΣc threshold and a second one at 2.8GeV,which lies below the DN threshold.Both structures are states with the Λc -like quantum numbers.Whether the ?rst resonant structure is the in-medium Λc (2593)resonance and the second bump is a new resonance is something that deserve further analysis.

L.Tol′o s,J.Scha?ner-Bielich,A.Mishra:D-mesons in dense nuclear matter

3

2300

2500

2700s 1/2

(MeV)0

255075100

?I m G D N (M e V f m 3

)

?50?2502550

75100

125 ?R e G D N (M e V f m 3

)

Tmatrix

Gmatrix (dmeson)Gmatrix

23002500

27002900

s 1/2

(MeV)

Fig.2.Real and imaginary parts of the DN amplitude for s-wave in the I =0(left panels)and I =1(right panels)channels as functions of the center-of-mass energy at total mo-mentum zero for Λ=1GeV and g 2=13.4and for di?erent approaches:T-matrix calculation (dotted lines),self-consistent calculation for the D-meson at ρ=ρ0(solid lines),where ρ0is the nuclear saturation density,and self-consistent calculation for the D-meson including the dressing of nucleons and the pion self-energy at ρ=ρ0(long-dashed lines).0

0.1

0.20.3

0.4

ρ(fm ?3

)

?160

?120?80?400I m U D N (M e V )

I=0 for Λ=1.0 GeV, g 2

=13.4

I=1 for Λ=1.0 GeV, g 2

=13.4

?100?80?60?40?20020R e U D N (M e V )

Λ=0.8 GeV,g 2

=12.8

Λ=1.0 GeV,g 2

=13.4

Λ=1.4 GeV,g 2

=14.5

0.1

0.20.3

0.4

0.5

ρ(fm ?3

)

Fig.3.Real and imaginary parts of the D-meson potential at k D =0as functions of the density,including the isospin decomposition for Λ=1GeV and g 2=13.4,for di?erent sets of coupling constants and cuto?s and the two self-consistent approaches discussed in the text:self-consistent calculation for the D-meson (left panels)and self-consistent calculation of the D-meson including the dressing of nucleons and pions (right panels).

1600170018001900ωD (MeV) 0

1

23456

78S D (k D =0,ω) (G e V ?2

)

ρ=0.5ρ0

ρ=ρ0

ρ=1.5ρ0

16001700180019002000

ωD (MeV)

Fig. 4.D-meson spectral density at k D =0as a function of energy with Λ=1GeV and g 2=13.4for di?erent densities and for the two approaches discussed in the text:self-consistent calculation for the D-meson (left panel)and self-consistent cal-culation of the D-meson including the dressing of nucleons and pions (right panel).

The dependence on the cuto?and coupling constants together with the isospin decomposition of the in-medium DN interaction have also been a matter of study.In Fig.3we show the real and imaginary parts of the D-meson potential at k D =0as functions of the density for the two self-consistent approaches that were mentioned be-fore:self-consistent calculation for the D-meson (left pan-els)and self-consistent calculation of the D-meson includ-ing the dressing of nucleons and pions (right panels).With regards to the isospin decomposition,when only D-mesons are dressed,the D-meson potential is governed by the I =1component while,when nucleons and pions are dressed,the I =0component dominates because of the structure at 2.8GeV present in the G-matrix.On the other hand,we observe a weak dependence on the chosen set of cuto?s and coupling constants.It is interesting to see that,for any chosen parameters,the coupled-channel e?ects seem to result in an overall reduction of the in-medium e?ects independent of the in-medium properties compared to previous literature [9,10,11,12].For exam-ple,when only the D -meson is dressed,we obtain a range of values for the D -meson potential at ρ=ρ0between 8.6MeV for Λ=0.8GeV and -11.2MeV for Λ=1.4GeV.For the full self-consistent calculation,the range of values covered lies in between 2.6MeV for Λ=0.8GeV and -12.3MeV for Λ=1.4GeV.

Finally,once the self-consistency is reached,we cal-culate the full D-meson self-energy and the correspond-ing spectral density.The spectral density at zero momen-tum is shown in Fig.4for Λ=1GeV and g 2=13.4,and for several densities in the two self-consistent ap-proaches considered before.When only the D-meson is

4L.Tol′o s,J.Scha?ner-Bielich,A.Mishra:D-mesons in dense nuclear matter

dressed self-consistently(left panel of Fig.4),the quasi-particle peak moves slightly to lower energies as density increases since the D-meson potential becomes more at-tractive(see left panels of Fig.3).TheΛc resonance is seen for energies around1.63-1.65GeV as a second peak on the left-hand side of the quasiparticle peak.For the sec-ond approach when nucleons and pions are dressed(right panel of Fig.4),the structure around2.8GeV of Fig.1 mixes with the quasiparticle peak which translates into a broadening of the spectral density at the quasiparticle energy.

4Concluding remarks

We have performed a microscopic self-consistent coupled-channel calculation of the single-particle potential and, hence,the spectral density of a D-meson embedded in symmetric nuclear matter taking,as bare interaction,a separable potential[13].TheΛ(2593)c resonance has been obtained dynamically.We have also studied the medium e?ects on that resonance and,therefore,on the D-meson potential coming from the Pauli blocking and the dress-ing of nucleons and pions.We have concluded that,inde-pendently of the medium properties of the intermediate states,the self-consistent coupled-channel e?ects result in a small attractive real part of the in-medium D-meson potential.However,the production of D-mesons in the nuclear medium will be still enhanced due to the broad D-meson spectral density.This e?ect is similar to the one obtained for the enhancedˉK production in heavy-ion colli-sions[16],where the overlap of the Boltzmann factor with the strength in the low-energy region of theˉK spectral density turned out to be a source of additional attraction and,hence,increased the produced number ofˉK.The in-medium e?ects seen in this work can be studied with the future PANDA experiment at GSI[17].In this experiment, in-medium changes of the open charm hadrons will be ad-dressed by the study of the excitation function and the correlation function of D andˉD mesons. Acknowledgment

L.T.wishes to acknowledge?nancial support from the Alexander von Humboldt Foundation.

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感叹句用法讲解

感叹句 感叹句(exclamatorysentence)用来表示说话人喜怒哀乐、惊讶、赞美等强烈感情的句子。用降调，句末用感叹号，句首多用how和what，其余与陈述句结构相同。 1、带有how的感叹句 用来感叹形容词、副词或动词，其结构： （1）How＋形容词＋主语＋谓语! How happy he is!他是多么的幸福啊! How exciting he became when he heard the news!当他听到这个消息时，他是多么的激动！How beautiful the West Lake is!西湖是多么的美丽啊! （2）How＋副词＋主语＋谓语! How hard he is working now!他现在工作得多么的努力呀! How slowly he runs!他跑得多么慢呀! How beautifully you sing!你唱得多么好听啊！ （3）How＋主语＋动词! How her mother worried!她母亲是多么地担心啊! How he enjoys collecting stamps!他是多么的喜欢集邮啊! How the men pumped like crazy!水手们发疯般地抽着水！ （4）How+形容词+a(an)+可数名词单数形式 Miss Langham arm in arm with Mr.Peabody——how astonishing a sight!兰哈姆小姐挽着皮博迪先生的胳膊，看上去真叫人吃惊！ How interesting a book it is!多么有趣的一本书啊！

（5）How+ many, much, few, little+名词+主语＋谓语! How little food they have!他们的食物多么少啊！ How few books she has!他有的书多么少啊！ 2、带有what的感叹句 带有what的感叹句用来感叹名词，被感叹的名词既可以是可数名词（单数形式或复数形式），也可以是不可数名词。 （1）What a/an＋(形容词)＋单数名词＋谓语! What a fine day it is!天气多么好啊! What an interesting story it is!它是多么有趣的一个故事啊! What an honest boy he is!他是一个多么诚实的孩子呀! What a beautiful day it was and how happy I was!天是多么的好，我是多么的高兴啊!（2）What＋(形容词)＋复数名词＋谓语! What funny stories they are!他们是多么可笑的故事啊! What beautiful colours they are!它们的颜色是多么的漂亮啊! What terrible earthquakes they are!多么可怕的地震啊! （3）What＋(形容词)＋不可数名词＋谓语! What great progress he has made!他取得了多么大的进步呀! What terrible weather we met!我们那时遇到了多么可怕的天气啊! What fun it is to have a swim in summer.夏天游泳是多么有趣的是啊！ 3、感叹句的特殊表达法 （1）不定式短语引起的感叹句

高中英语 知识点大全4 admire、affect、afraid的用法

高中英语知识点大全（4）：admire、affect、afraid的用法1、admire admire（= respect / praise）vt.羡慕，钦佩，夸奖 admire sb.（for sth.）佩服某人某事 Visitors to Beijing greatly admire our Palace Museum. 去北京的游人极其羡慕我们的故宫。 I admire him for his wisdom.我佩服他的智慧。别忘了夸奖孩子。 对比：envy（= jealous）vt.嫉妨，羡慕 envy sb.（sth.）嫉妒/羡慕某人某事 We all envy you your good future. 我们都很羡慕你的好运。 2、affect affect（=have an effect on sth.）vt.影响（effect n.影响） This may affect your health. 这或许会影响你的健康。 My throat is always affected by bad weather.我的嗓子总是受恶劣天气的影响。 3、afraid 1)“be afraid of+名词”，意为“害怕”。 2）“be afraid of doing sth”意为“担心，害怕……”。 3）“be afraid for…”意为“为……担心。” 4）“be afraid that…”意为“担心，恐怕”。 5）“be afraid to do ”意为“害怕，担心而不敢做某事”。

6）I’m afraid so/not.恐怕是这样/恐怕不会这样 [应用]完成句子 ①女孩子一般都怕蛇。Girls are usually______ _____snakes. ②他怕把杯子打碎，因而很小心。He was careful because he was afraid______ _____the glass. ③你不为自己的安全担心吗？Are you afraid_______your safety? ④恐怕她会迷路。I am _____ _____she will lose her way. ⑤汤姆把钱丢了，也不敢告诉他母亲。Tom lost the money and was afraid________ ______his mother. Key:①afraid,of ②of,breaking ③for ④afraid,that ⑤to tell

感叹句的用法

教学目标： 1.让学生了解感叹句。 2.感叹句的三种构成方法。 3 掌握由how和what引导的感叹句。 教学重点： 1 掌握有how和what引导的感叹句. 2 能把how和what引导的两种感叹句互换形式。 教学过程： 第一步：导入、复习 1 感叹句：用以表示喜怒哀乐等强烈感情的句子。如： Look ! Great ! 2 感叹句的标志性符号即感叹号“！”。 3 感叹句一般读降调。 How carefull he studies !(读降调) 第二步：呈现、质疑 1 陈述句、疑问句可构成感叹句。如： It sounds great ! Isn't it interesting ! It's a fine day today ! 2 单词或短语均可构成感叹句。如： Help! Look out! Well done! 3 How或what引导的感叹句。如： How clever! What sweet music! 第三步：拓展提升 1 What引导的感叹句。 What a beautiful girl !

What delicious food ! What bad wheather ! 2 How引导的感叹句。 How exciting ! How big a room (it is) ! How many books he has ! How time flies ! 第四步：知识梳理 1 What 引导的感叹句 What+a\an+形容词+可数名词单数（+主谓）！ What a cute dog ! What+形容词+可数名词复数（+主谓）！ What beautfull flowers ! What+形容词+不可数名词！ What+主语+谓语！ What she must have suffered ! 2 How 引导的感叹句 How+形容词或副词(+主谓）！ How wonderfull ! How+形容词+a\an+可数名词（+主谓）！ How big a room it is ! How+many\much\few\little+名词（+主谓）！ How many books he has ! How+主语+谓语！ How time flies ! 第五步：检测、总结 一将"He is a clever boy. ”变为感叹句. 1 How cever he is ! 2 What a clever boy he is ! 二将What a big room it is !变为由How引导的感叹句。

afraid用法详解总结

afraid用法详解总结 今天给大家带来了afraid用法详解，快来一起学习吧，下面就和大家分享，来欣赏一下吧。 afraid用法详解 【基本用法】 1.害怕的，恐惧的： Dont be afraid. 别怕。 She is afraid of dogs. 她怕狗。 She is afraid of snakes. 她怕蛇。 He was afraid of nothing. 他什么也不怕。 She was afraid of waking him. 她担心把他吵醒。 She was afraid to see you again. 她怕再次见到你。 1 was afraid to tell you. 我不敢告诉你。 They were afraid to be seen by others. 他们怕被别人看到。

He is afraid he will die. 他害怕他会死。 I was afraid I might hurt your feelings. 我担心我会伤害你的感情。 She was afraid they would recognize her. 她担心他们会认出她来。 2.担心的： Im afraid that he wont come. 我担心他不会来。 "Is he not coming?" "I am afraid not.(I’m afraid so.)" “他不来吗?”“看来不会(怕是这样)。” I’m afraid l can’t stay. 恐怕我不能待了。 I’m afraid you don’t see my point. 恐怕你没听懂我的意思。 “Are we late?” “I’m afraid so. ” “我们迟到了吗?”“怕是迟到了。” I’m afraid I must ask you to leave the country. 对不起我得让你离开这个国家。 【考点说明】 1. 通常用作表语，不用于名词前作定语。

初中英语感叹词总结

感叹词是用来表示说话时表达的喜怒哀乐等情感的词。它不构成后面句子的一个语法成分，却在意义上与它有关连，后面的句子一般说明这种情绪的性质、原因。感叹词是英语口语中最富于表现力的词语之一，用途甚广。学会它，对于提高英语的交际能力，表达复杂的思想起着举足轻重的作用。英语中的感叹词很多，但目前的语法著作中却很少对它进行归纳总结，致使许多人对含有感叹词的句子理解不透。现将部分感叹词的用法进行小结： 一、Oh 表示惊讶、指责、痛苦、称赞、懊恼等，可译为“哦”、“哎呀”、“噢”“啊”、“呀”等。 1.“Oh，who was that？” Mr. Black asked.“哦，是谁？”布莱克先生问。 2.“Oh，how blind you are！” he cried.“哎呀，你们真瞎！”他大声道。 3.“Oh，oh！” he cried.“My stomach！My head！oh！oh！”“哎呀，哎哟！”他大声道，“我的肚子！我的头！哎哟！哎哟！” 4.Oh，learned judge！Oh，wise young man.噢，博学的法官！噢，聪明的年轻人！

二、Ah表示惊奇、高兴、讨厌、懊悔、藐视、威胁等，可译为“呀、啊”等。 1.Ah，yes，Jeanne married a man with a lot of money.啊，对啦，让娜嫁给了一个很有钱的人。 2.“Ah，what splendid clothes！” thought the Emperor.“啊！多华丽的衣服啊！”皇帝想。 3.Ah，how pitiful！呀，多可惜！ 4. Ah，here is the thing I am after.哎呀，我找的东西在这儿呢。 三、come表示鼓励、不耐烦、引起注意、安慰等，可译为“喂、好吧、说吧、得啦”等。 1.Oh，come，Mathilde.Surely you can tell an old friend.嗨，说吧，玛蒂尔德，你对老朋友说说总是可以的吧。 https://www.wendangku.net/doc/cf18629094.html,e，we must hurry.喂，我们得赶紧啦！ https://www.wendangku.net/doc/cf18629094.html,e，come，get him his change.Tod，get him his change.好吧，好吧，托德，快把钱找给他，快把钱找给他。 4. Come，come！What were you really doing behind the bicycle sheds？喂！喂！你还在车棚里磨蹭啥？

Admire用法和常见搭配

Admire用法和常见搭配 China and Japan have mid-autumn festivals, when people admire the moon and in China, enjoy mooncakes. (P2) 中国和日本都有中秋节，这时，人们会赏月。在中国，人们还品尝月饼。 [点拨]admire vt 倾佩，赞赏，羡慕；夸奖；喜欢admiration n倾佩，赞赏，羡慕admire sb for / (doing) sth 因某事而倾佩、羡慕某人 express admiration for sb对某人表示倾佩I admire her for the way she solves the problem.我倾佩她解决问题的方式。 I admire her for her beauty.我羡慕她的美丽。 I admired and respect you more than I can say. I admired him for his success in business. Everybody admires him for his fine sense of humour. [运用]翻译下列句子 1) 我们佩服居里夫人的发现。

_________________________________________ _________________ 2) The school is widely admired for its excellent teaching. _________________________________________ __________________

高考总复习英语知识点大全4：admire、affect、afraid的用法

v1.0 可编辑可修改高中英语知识点大全（4）：admire、affect、afraid的用法 1、admire admire（= respect / praise）vt.羡慕，钦佩，夸奖 admire sb.（for sth.）佩服某人某事 Visitors to Beijing greatly admire our Palace Museum. 去北京的游人极其羡慕我们的故宫。 I admire him for his wisdom.我佩服他的智慧。 对比：envy（= jealous）vt.嫉妨，羡慕 envy sb.（sth.）嫉妒/羡慕某人某事 We all envy you your good future. 我们都很羡慕你的好运。 2、affect affect（=have an effect on sth.）vt.影响（effect n.影响） This may affect your health. 这或许会影响你的健康。 My throat is always affected by bad weather.我的嗓子总是受恶劣天气的影响。 3、afraid 1)“be afraid of+名词”，意为“害怕”。 2）“be afraid of doing sth”意为“担心，害怕……”。 3）“be afraid for…”意为“为……担心。” 4）“be afraid that…”意为“担心，恐怕”。 5）“be afraid to do ”意为“害怕，担心而不敢做某事”。 6）I’m afraid so/not.恐怕是这样/恐怕不会这样 [应用]完成句子 ①女孩子一般都怕蛇。Girls are usually______ _____snakes. ②他怕把杯子打碎，因而很小心。He was careful because he was afraid______ _____the glass. ③你不为自己的安全担心吗Are you afraid_______your safety ④恐怕她会迷路。I am _____ _____she will lose her way. ⑤汤姆把钱丢了，也不敢告诉他母亲。Tom lost the money and was afraid________ ______his mother. Key:①afraid,of ②of,breaking ③for ④afraid,that ⑤to tell - 1 -- 1 -

感叹词

感叹词 感叹词: 感叹词是用来表示说话时表达的喜怒哀乐等情感的词。它不构成后面句子的一个语法成分，却在意义上与它有关连，后面的句子一般说明这种情绪的性质、原因。感叹词的缩写形式：int.,是英文interjection的缩写 感叹词的用途: 感叹词是英语口语中最富于表现力的词语之一，用途甚广。学会它，对于提高英语的交际能力，表达复杂的思想起着举足轻重的作用。英语中的感叹词很多，但目前的语法著作中却很少对它进行归纳总结，致使许多人对含有感叹词的句子理解不透。现将部分感叹词的用法进行小结： 感叹词的用途分类 Oh: 表示惊讶、指责、痛苦、称赞、懊恼等，可译为“哦”、“哎呀”、“噢”“啊”、“呀”等。 1．“Oh，who was that？” Mr. Black asked．“哦，是谁？”布莱克先生问。 2．“Oh，how blind you are！” he cried．“哎呀，你们真瞎！”他大声道。 3．“Oh，oh！” he cried．“My stomach！My head！oh！oh！” “哎呀，哎哟！”他大声道，“我的肚子！我的头！哎哟！哎哟！” 4．Oh，learned judge！Oh，wise young man．噢，博学的法官！噢，聪明的年轻人！ Ah 表示惊奇、高兴、讨厌、懊悔、藐视、威胁等，可译为“呀、啊”等。 1．Ah，yes，Jeanne married a man with a lot of money．啊，对啦，让娜嫁给了一个很有钱的人。 2．“Ah，what splendid clothes！” thought the Emperor．“啊！多华丽的衣服啊！”皇帝想。 3．Ah，how pitiful！呀，多可惜！ 4．Ah，here is the thing I am after．哎呀，我找的东西在这儿呢。 come表示鼓励、不耐烦、引起注意、安慰等，可译为“喂、好吧、说吧、得啦”等。 1．Oh，come，Mathilde．Surely you can tell an old friend． 嗨，说吧，玛蒂尔德，你对老朋友说说总是可以的吧。 2．Come，we must hurry．喂，我们得赶紧啦！ 3．Come，come，get him his change．Tod，get him his change． 好吧，好吧，托德，快把钱找给他，快把钱找给他。 4．Come，come！What were you really doing behind the bicycle sheds？ 喂！喂！你还在车棚里磨蹭啥？ dear表示后悔、难过、怜悯、同情、吃惊、盼望等，可译为“哎呀、天哪”等。 1．Dear me！What awful weather！哎呀！多糟的天气！ 2．Oh，dear，dear！Where can Harry be？天哪，天哪，亨利会在哪儿？ 3．Dear，dear！Where have I put my keys？哎呀，我把钥匙放在哪啦？ 4．“Dear me，” he said to himself，“Am I foolish or unfit for my office？” “哎呀！”他心里嘀咕着，“我是愚蠢呢还是不称职？” well表示快慰、让步、期望、讥讽、解释、责备、犹豫等，可译为“好吧、不过、好啦、嗯”等。 1．Well，your father has found him in the garage．好啦，你父亲在车库里找到他了。 2．Are you sure？Well，perhaps you，are right．你能肯定吗？嗯，也许你说得对。 3．Well，you must come to lunch tomorrow．不过，你明天一定要来吃午饭。 4．I handed the note to him and said，“Oh，very well，I apologize．”

十类英语感叹词详解

十类英语感叹词详解 感叹词是用来表示说话时表达的喜怒哀乐等情感的词。它不构成后面句子的一个语法成分，却在意义上与它有关连，后面的句子一般说明这种情绪的性质、原因。感叹词是英语口语中最富于表现力的词语之一，用途甚广。学会它，对于提高英语的交际能力，表达复杂的思想起着举足轻重的作用。 英语中的感叹词很多，但目前的语法著作中却很少对它进行归纳总结，致使许多人对含有感叹词的句子理解不透。现将部分感叹词的用法进行小结： 一、Oh 表示惊讶、指责、痛苦、称赞、懊恼等，可译为“哦”、“哎呀”、 “噢”“啊”、“呀”等。 1. "Oh, who was that?" Mr. Black asked. “哦，是谁？”布莱克先生问。 2. "Oh, how blind you are!" he cried. “哎呀，你们真瞎！”他大声道。 3. "Oh, oh!" he cried. "My stomach! My head! Oh! Oh! “哎呀，哎哟！”他大声道，“我 的肚子！我的头！哎哟！哎哟！” 4. Oh, learned judge! Oh, wise young man. 噢，博学的法官！噢，聪明的年轻人！ 二、Ah表示惊奇、高兴、讨厌、懊悔、藐视、威胁等，可译为“呀、啊” 等。 1. Ah, yes, Jeanne married a man with a lot of money. 啊，对啦，让娜嫁给了一个很有 钱的人。 2. "Ah, what splendid clothes!" thought the Emperor.“啊！多华丽的衣服啊！”皇帝想。 3. Ah, how pitiful! 呀，多可惜！ 4. Ah, here is the thing I am after. 哎呀，我找的东西在这儿呢。 三、come表示鼓励、不耐烦、引起注意、安慰等，可译为“喂、好吧、 说吧、得啦”等。 1. Oh, come, Mathilde. Surely you can tell an old friend. 嗨，说吧，玛蒂尔德，你对老 朋友说说总是可以的吧。 2. Come, we must hurry. 喂，我们得赶紧啦！ 3. Come, come, get him his change. Tod, get him his change. 好吧，好吧，托德，快把

英语主动表被动用法归纳

英语主动表被动用法归纳 一、谓语动词用主动表被动的五种情形 (1)某些连系动词(如look, sound, smell, feel, taste, prove等)要用主动表被动，因为连系动词为不及物动词，它们没有被动语态形式： That dog looks dangerous. 那只狗看起来很危险。 Your idea sounds a good one. 你的想法听起来很好。 My advice proved to be wrong. 我的意见证实是错的。 (2)当open, close, shut, lock, move等用作不及物动词且表示主语的某种属性时，通常用主动形式表示被动意义： The door won’t shut. 这门关不上。 The supermarket doors shut automatically. 超市的门是自动关的。 【注】该用法的不及物动词通常与can’t, won’t 等连用，注意它与用被动语态含义不同：The window won’t shut. 这窗户关不上。(说明主语的属性——窗户有问题了) The window won’t be shut. 这窗户将不用关上。(窗户本身没问题，只是不用关) 有时可能用主动和被动形式均可，只是强调重点稍有不同： Suddenly the door opened. 突然门开了。(不强调动作执行者) The door was suddenly opened. 门突然被打开了。(强调动作执行者) (3)当read, wash, clean, cook, cut, wear, carry等用作不及物动词且表示主语的某种属性时，通常要用主动形式表示被动意义： The cloth washes well. 这种布料好洗。 The book sells quickly. 这书销售得快。 This cheese doesn’t cut easily. It’s too soft. 这乳酪不容易切，太软了。 This shirt will wear very long. 这衬衫可以穿很久。 【注】该用法通常与well, easily, slowly, quickly等副词连用，并且在用于以上意思时通常不宜直接使用被动语态形式。不过在某些特殊情况下也可用被动语态，只是含义稍有不同(用主动形式表示主语的属性，用被动形式表示动作执行者所执行的动作)：The sentences read clearly. 这些句子读起来很清楚。(即这句子没有歧义) The sentences are read clearly. 这些句子被读得很清楚。(指读的人读得好) 另外，以上用法有时也可能用于进行时态： The vegetables are cooking. 蔬菜正在煮着。 Is the book selling well? 这书销售情况如何?

史上最全的 构词法 用法详解

史上最全的构词法用法详解 语言中词的总和构成词汇，但是词汇并不是一堆杂乱无章、互不相关的群体，而是一个严密体系，在这个结构的体系中，词与词之间有着各种各样的联系。英语中的这些联系的规律总结起来就是构词。英语中构词的方法就是构词法。构词法主要有合成法、转化法、派生法和缩略法四种。掌握构词法是迅速扩大词汇量的重要方法之一。 第一节合成法 合成法就是指由两个或两个以上的单词合成的词叫合成词。这种构词方式主要有两种：复合法、结合法。合成法主要是构成合成名词和合成形容词。 复合法构成的复合词，它们各个结合的部分相互间的语法关系是紧密相关的。如blackboard和darkroom都是形容词和名词形成的结构，wr it ing desk是动词名词和名词形式的结构。 结合法形成的词是形态合成词，它的结合是用一个起来连接作用的中缀来把两个或两上以上的词根词素紧紧的连缀在一起。如，用辅音字母－s－来缀全两个词根词素构成的词有：salesman, towns people等。 合成的方式常见的有如下几种： 一、合成名词 1、名词／代词＋名词： woman-doctor, women-doctors, workshop, spaceship, he-goat, coal fire, motorcycle, gas cooker, oil well, power plant, silk worm, gold mine, bottleneck, piano keys, teleph one receiver, television screen, chairman, fireman, motorman, police-officer, postman, pine tree, girl friend, boy friend, goldfish, raindrop, birdcage, breakfast time, flowerbed, tearoom, 2、动词＋名词：blowpipe, flashlight, watchdog, call-girl, searchlight 3、形容词＋名词： blacksmith, blackboard, supermarket, superman, darkroom, blackbird, highchair, hothouse, greenhouse, madman 4、动名词＋名词： reading-room, sitting-room, classroom, schoolroom, dining room, building materials, dancing girl, cleaning women, flying machine, washing machine, working conditions, boilding point, drinking water, swimming pool, drinking cup, typing paper, writing desk, sewing machine, walking stick,

感叹句的用法

【概念】 英语中的感叹句用法 感叹句一般用来表示说话时的喜悦、惊讶等情感。 【句式】 感叹句由what 或how引导。what引导的感叹句中心词为名词，how引导的感叹句中心词为形容词或副词。 What+(a / an)+形容词+名词+主语+谓语动词或系动词！ How +形容词或副词+主语+谓语动词或系动词！如： What a beautiful flower it is! What an interesting story it is! What interesting work it is! How interesting the story is! How hard he works! How nice you are, Helen! 当what感叹句中的名词前有形容词修饰时，该句可改为how感叹句，如： What a beautiful flower it is! = How beautiful the flower is! 【如何将陈述句变为感叹句】 以下列句子为例： a. She is a good teacher. b. The flowers smell sweet. 先找句子的主语和谓语动词或系动词，并将之与其他部分划分开； a. She is | a good teacher. b. The flowers smell | sweet.

若其他部分中心词是名词，则用what引导；若中心词是形容词或副词，则用how 引导。a句的中心词为teacher，b句的中心词为 sweet，为此分别用what, how 引导，然后按照感叹句语序写出句子，即： a. What a good teacher she is! b. How sweet the flowers smell! 又如： a. He did so fast. b. She read a good book yesterday.→ a. He did│so fast. b. She read│a good book yesterday.→ a. How fast he did! b. What a good book she read yesterday! 追问： 如果How引导的感叹句省主语和谓语动词 如何在选择题中判断到底是How还是What？-

英语词汇用法

英语词汇用法 1.a/an/the/a book/an apple/an “s”/an hour/a European/at a loss/ in danger/at risk/go on a diet/for fun/be great fun/have a knowledge of 2.abandon one’s family/abandon one’s plan 3.work to the best of one’s ability/ develop one’s ability of listening/ have the ability to do sth 4.be unable to do anything but wait/ an able man 5.abnormal/normal 6.go aboard/go aboard a ship 7.was about to do sth when…/was on the point doing sth = happened to be doing sth when…/what about =how about sth?/set about doing sth=set out to do sth 8.be above the sea level/sb/be ahead of sb/above all 9.go abroad for futher study 10.in the absence of sb/sth = for lack of sth/ sb/sth be absent from 11.absolute ignorance/absolute power /absolute proof/relative/absolutely/ definitely 12.Black cloth absorbs light/absorb a heavy blow/be absorbed in 13.The idea of happiness is abstract/ the abstract of book 14.abuse one’s eye/abuse one’ son 15.academic degree/an academic interest in politics 16.accept…as…/be acceptable to sb 17.the only access to the village/gain access to the house through the window/have/obtain the access to the Internet/be accessible to my car(by car) 18.by accident = by chance = accidentally = occasionally/ accidental 19.accommodation 20.accompany sb to the school/keep sb company/be with/stay with sb/ accompany the singer on piano 21.accomplish wonders/something/ nothing 22.according to what he said/the fact that he was ill 23.account for = explain(to sb)= bring out = set out/account for 4%/ give sb a vivid account of=report vividly/open a bank account/on account of/on no account=under no circumstances=by no means=in no way/at no time/by no means will I do/accountant 24.accumulate a large fortune 25.accurately/accurate timing/timer/ accuracy 26.accuse sb of doing sth/theft/charge sb with doing sth 27.accustom children to getting up early/get (oneself) accustomed to/ accustom oneself to new surrounding 28.achieve one’s goal/set one’s goal/ achieve nothing without effort/ achievement 29.acid taster/acid rain 30.acknowledge doing sth / one’s mistake/acknowledge one’s letter/ be acknowledge as(to be)/admit 31.acquire = obtain 32.get across/ run across/come across = meet with/3 meters across/shout across (through) the room/across the station 33.an act of kindness/in the act of… /Act. / act the part of sb / act out dialogue/act as/act as if/act for /act on(upon) /take strict action to

小学语文感叹句的用法

小学语文感叹句的用法 在劳动场合，人们为了干得更起劲，常常会喊起劳动号子：“同学们，加油干______!” 在这个感叹句中，句末一个字是“干(gàn)”，它的韵尾是“n”，加上韵母“a”合成“na”(哪)，所以这个感叹句中的语气助词应用“哪”。 在花好月圆的晚上，当你凝望窗外的月亮时，会情不自禁地赞叹：“月亮真圆______!” 此句中末字是“圆(yuán)”，它的韵尾是“n”，加上韵母“a”，合成“na”(哪)，因此，这句话中的语气助词也用“哪”。 小学语文感叹句的用法 当你外出旅游，来到黄山、庐山、九寨沟等风景名胜区时，美景立即映入你的眼帘，此时，你定会由衷赞叹：“这里的风景真美______!” 这个感叹句中末字是“美(měi)”，它的韵尾是“i”，加上韵母“a”，合成“ia”，这里的语气助词应用“呀(ya)”。 同学们，你们都读过《狐狸和乌鸦》这个故事吧!那狐狸诡计多端，用花言巧语骗走了乌鸦嘴里的鲜美嫩肉，多么得意!读后，你肯定会说：“多么狡猾的狐狸______!” 这个感叹句中末字是“狸(lí)”它的韵尾是“i”，加上韵母“a”，合成“ia”，所以这里的语气助词也用“呀(ya)”。 小学语文感叹句的用法 如果感叹句末尾那个字的韵尾和韵母“a”不能相拼，就用语气助词“啊”。

如：“多么可爱的鸟儿________!” 这个感叹句中末字是“儿”，它的韵尾是“r”，和韵母“a”不能相拼，就用语气助词“啊”。 又如：“今天我真高兴______!” 此句中“兴”的韵尾是“ng”，和韵母“a”也不能相拼，所以也用“啊”。 有时，“哪”“呀”“哇”也可通用为“啊”，但朗读时仍要按上述规律确定读音。 小学语文感叹句的用法 当你吃到那香喷喷的大米饭时，你的眼前是否会浮现出农民伯伯在田间耕种、收割时那面朝黄土背朝天的劳动情景呢?你一定会说：“我们应爱惜每一粒米，农民伯伯是多么辛苦______!” 这个感叹句中末字是“苦(kǔ)”，它的韵尾是“u”，加上韵母“a”，合成“ua”，这里的语气助词应用“哇(wa)”。 过新年了，当你高高兴兴地穿上新衣服去给亲戚朋友拜年时，他们看见了，会说：“多么漂亮的衣服______!” 此句中末字“服(fú)”的韵尾是“u”，加上韵母“a”，合成“ua”，所以这里的语气助词也用“哇(wa)”。

英语中常用的感叹词

英语中常用的感叹词 感叹词是用来表示说话时表达的喜怒哀乐等情感的词。它不构成后面句子的一个语法成分，却在意义上与它有关连，后面的句子一般说明这种情绪的性质、原因。感叹词是英语口语中最富于表现力的词语之一，用途甚广。学会它，对于提高英语的交际能力，表达复杂的思想起着举足轻重的作用。英语中的感叹词很多，但目前的语法著作中却很少对它进行归纳总结，致使许多人对含有感叹词的句子理解不透。现将部分感叹词的用法进行小结 一、Oh 表示惊讶、指责、痛苦、称赞、懊恼等，可译为“哦”、“哎呀”、“噢”“啊”、“呀”等。 1. "Oh, who was that?" Mr. Black asked. “哦，是谁？”布莱克先生问。 2. "Oh, how blind you are!" he cried. “哎呀，你们真瞎！”他大声道。 3. "Oh, oh!" he cried. "My stomach! My head! oh! oh! “哎呀，哎哟！”他大声道，“我的肚子！我的头！哎哟！哎哟！” 4.Oh, learned judge! Oh, wise young man. 噢，博学的法官！噢，聪明的年轻人！ 二、Ah表示惊奇、高兴、讨厌、懊悔、藐视、威胁等，可译为“呀、啊”等。 1. Ah, yes, Jeanne married a man with a lot of money. 啊，对啦，让娜嫁给了一个很有钱的人。 2. "Ah, what splendid clothes!" thought the Emperor. “啊！多华丽的衣服啊！”皇帝想。 3. Ah, how pitiful! 呀，多可惜！

as引导的从句用法

1 as引导的从句崔长平河南省遂平中学（463100） 在英语中，as作为一个常见的从句引导词，其用法和意义十分活跃而丰富，若不加以区分，很容易造成混淆。现将其主要用法归纳如下： 1）引导时间状语从句①在as引导的时间状语从句中，谓语动词既可以是延续性的也可以是非延续性的；有时从句的谓语动词也可用进行时形式。②as引导的时间状语从句常可用来强调主、从句中的动作同时发生或伴随发生，常译作“随着……”，“一边……一边……”，“一……就……”等。③在省略句中，as之后经常放置一个名词或名词词组。 I heard the murmur of their voices as I crossed the hall. A look of surprise came into Alison’s eyes as she read the message. Scott became nervous as he saw her face. Just as he was speaking there was a loud explosion. He smiled as he passed. As she sang，the tears ran down her cheeks. We get wiser as we get older. As a young man，he was a store keeper and later a postmaster. 2）引导让步状语从句象although，though，while一样，as也可以用来引导一个让步状语从句，意为“尽管，虽然”， as引导的这种让步状语从句语气比较强，语体正规，经常用于书面语言，但as引导的让步状语从句须倒装。其倒装要求如下：①表语＋as＋主语＋系动词（表语经常是由形容词、分词、或名词充当；名词用作表语时，其前不能加用冠词。） Young as he is，he is equal to the task. Crowded as the restaurant was，they tried to find a table. Child as he was，he knew what was the right thing to do. ②状语﹢as﹢主语﹢谓语动词（这一结构中的谓语动词一般是行为动词，既可以是及物动词（带宾语）也可以是不及物动词。） Hard as he studied，he did not get good marks in the exam. Early as we got there，our teacher was there before us. Much as I admire him as a writer I don’t like him as a man. ③动词＋as ＋主语＋……（在这一结构中，主语后面一般加上情态动词may，might，will，would，can，could等，句首的动词应该保持原形。如果从句中没有情态动词，那么，应在从句的主语之后（根据时态和数的要求）加上助动词do、does或did。在这一结构中，放在句首的动词如果是及物动词，那么，这个动词连同它的宾语一起放到as之前。） Search as they would，they could find nothing in the house. Try as he may，he will fail in the examination. Die as he did，his inspiration lived on. Lose money as I did，I got a lot of experience. 3）引导原因状语从句 as引导原因状语从句时，语气不及because强烈，它接近于since，now that，一般译作“既然，由于”之类的意义，只是“附带说明的理由”，表达一种说话人和听话人“共知的原因”。as引导的原因状语从句一般置于主句之前。 As all the seats were full he stood up. As Davidson had a passion for walking，we started off on foot. As you are sorry，I’ll forgive you. It is very difficult for us to know what to do as we are not his parents.