Light-Cone Distribution Amplitudes for Non-Relativistic Bound States

小学上册英语第6单元综合卷英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1.What is the capital of Italy?A. VeniceB. FlorenceC. RomeD. MilanC2. A __________ (混合物) can be separated into its components.3.They are _____ (climbing) the hill.4.The ancient Romans had a system of ________ to govern their empire.5.The ______ of a rose bush can be very thorny. (玫瑰灌木的茎可能非常多刺。

)6.The capital of Laos is __________.7. A __________ is a type of chemical reaction that produces energy in the form of light.8.What do we call the young of a cow?A. CalfB. KidC. LambD. Foal9.The burning of fossil fuels releases carbon ______.10.I enjoy visiting the ______ (农场) to see all the animals.11.The flower pot is colorful and ______.12.Which planet is known for having the highest mountain in the solar system?A. EarthB. MarsC. JupiterD. Venus13.我的朋友喜欢 _______ (活动). 她觉得这很 _______ (形容词)14.The green color of plants is due to ______.15.An alloy is a mixture of ______.16.What do you call a person who plays sports?A. AthleteB. ArtistC. ChefD. Scientist17.The __________ is the smallest continent in the world.18.What is the capital of Finland?A. HelsinkiB. StockholmC. OsloD. TallinnA19.What is the term for a person who studies rocks?A. GeologistB. BiologistC. ArcheologistD. ChemistA20.What do we call the energy from the sun?A. Solar energyB. Wind energyC. Nuclear energyD. Geothermal energyA21.What do we call the process of turning a caterpillar into a butterfly?A. MetamorphosisB. EvolutionC. TransformationD. GrowthA22.The capital of Sweden is _______.23.What is the opposite of "up"?A. DownB. LeftC. RightD. Forward24.I like to help my mom ________ (清理房间).25.I enjoy _______ (listening) to classical music.26.The cat loves to watch _______ from the window.27.Saturn has over known ______.28.What do we call the study of the human mind and behavior?A. PsychologyB. SociologyC. AnthropologyD. Philosophy29.ts can ______ (适应变化) in their environment. Some pla30.What is the capital city of the UK?A. LondonB. EdinburghC. CardiffD. BelfastA31.Which animal lives both on land and in water?A. HorseB. FrogC. BirdD. FishB32.My ______ enjoys playing board games.33.I enjoy riding my ______ (马) on the trails through the ______ (森林).34.Which of these is a type of tree?A. RoseB. OakC. DaisyD. TulipB35.The capital of Italy is _____ (26).36.The _____ (栽培) of plants is called horticulture.37.My teacher is very __________ (公平公正).38.The bird is singing a ______ (sweet) song.39.Which fruit is yellow and curved?A. OrangeB. AppleC. BananaD. GrapeC40.The North Star is also known as _______.41.The ancient Egyptians developed a unique system of ________ (书写).42.George Washington was the first __________ of the United States. (总统)43.What is the hardest natural substance on Earth?A. GoldB. DiamondC. IronD. Silver44.Sulfuric acid is a common industrial ________.45.兔子) hops around in the garden. The ___46. A _______ reaction absorbs heat from the surroundings.47.What do you call the large body of fresh water?A. OceanB. LakeC. RiverD. Sea48.What do we use to cut paper?A. GlueB. ScissorsC. TapeD. PencilB49.I like to make homemade ________ (果汁) during the summer to stay cool.50.The ant works hard to build its ______ (巢).51.Which animal is known for its shells?A. FishB. TurtleC. BirdD. Cat52. A _______ can be used to measure the temperature of different materials.53. A __________ (生态研究) helps inform conservation efforts.54.The __________ (历史的联系) underscores unity.55.What is the name of the famous painting by Leonardo da Vinci?A. The Starry NightB. The Last SupperC. Mona LisaD. Girl with a Pearl EarringC56. A ______ is a large-scale movement of the Earth’s crust.57.What do you call a large structure that holds water?A. ReservoirB. TankC. PoolD. BasinA58.The __________ (历史研究) is essential for understanding our place in the world.59.She is _______ (climbing) the ladder.60.What is the main ingredient in chicken soup?A. RiceB. NoodlesC. ChickenD. All of the aboveD61.What is the name of the famous desert in Egypt?A. SaharaB. GobiC. AtacamaD. MojaveA62.I want to _______ a great athlete.63.The ______ can be found in almost every habitat.64. A __________ is a mammal that is known for its intelligence.65.What is 2 + 2?A. 3B. 4C. 5D. 666.The element with the atomic number is ______.67.The firefly lights up the _________. (夜空)68.My _______ (宠物) rabbit is very friendly.69.What instrument do you blow into?A. GuitarB. FluteC. DrumsD. Violin70.The __________ were fierce warriors from Scandinavia. (维京人)71.I think that every person has the potential to be __________.72.I enjoy ___ (photography).73.What is the name of the tree that produces acorns?A. PineB. BirchC. OakD. MapleC74.The __________ (历史的思考) encourages critical analysis.75.We are going ________ a trip.76.The tortoise moves slowly across the _________. (地面)77.Who is the author of "Harry Potter"?A. J.K. RowlingB. Roald DahlC. Mark TwainD. Dr. SeussA78.My favorite ice cream flavor is ______.79.The skunk sprays when it feels _________. (威胁)80.What do we call the process of recycling waste materials?A. CompostingB. ReusingC. ReducingD. UpcyclingA81.What is the main purpose of a book?A. To cookB. To readC. To writeD. To draw82.The Earth's atmosphere contains layers such as the ______ and stratosphere.83.What is the name of the famous ship that is a symbol of love?A. TitanicB. Love BoatC. Queen MaryD. USS EnterpriseA84. A chemical reaction that requires heat to proceed is called an ________ reaction.85.What is the process of water turning into vapor called?A. CondensationB. EvaporationC. PrecipitationD. FiltrationB86.The chemical formula for amyl acetate is ______.87.The first successful heart-lung transplant was performed in ________.88.What is the main color of a polar bear?A. BrownB. WhiteC. BlackD. GrayB89.What is the primary ingredient in pancakes?A. FlourB. SugarC. EggsD. MilkA90.The element with the symbol Hg is __________.91.What is the capital city of the United Kingdom?A. DublinB. EdinburghC. LondonD. CardiffC92.The library has many ________.93. A _______ is a method of separating components based on their boiling points.94.The chemical formula for ammonia is __________.95.I see a _____ (老虎) at the zoo.96.My pet ______ (狗) loves to play fetch.97.The sky is _____ (clear/cloudy) today.98. A solution that does not conduct electricity is called a ______ solution.99.What is the largest rainforest in the world?A. Congo RainforestB. Amazon RainforestC. TaigaD. Temperate ForestB100.My mom loves to teach ____ (art) classes.。

光分布测试英语一、单词1. distribution- 英语释义：The way in which something is shared out among a group or spread over an area.- 用法：可作名词，常与“of”搭配，表示“……的分布”。

例如：the distribution of population（人口分布）。

- 双语例句：The distribution of resources is unequal in some regions.（在一些地区资源分配不平等。

）2. light- 英语释义：The natural agent that stimulates sight and makes things visible.- 用法：可作名词（光；光线）、动词（点燃；照亮）、形容词（轻的；浅色的）。

例如：a ray of light（一束光线）；Light the candle.（点燃蜡烛。

）；a light blue dress（浅蓝色的裙子）。

- 双语例句：The light in the room was too dim.（房间里的光线太暗了。

）3. test- 英语释义：A procedure intended to establish the quality, performance, or reliability of something.- 用法：可作名词（测试；试验）、动词（测试；检验）。

例如：a math test（数学测试）；test a new product（测试一种新产品）。

- 双语例句：We will have a driving test tomorrow.（我们明天有一场驾驶考试。

）4. measurement- 英语释义：The action of measuring something.- 用法：名词，常与动词“make”或“take”搭配，表示“进行测量”。

小学上册英语第四单元真题试卷(有答案)英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1.What do we call a young ostrich?A. ChickB. CalfC. KitD. Fawn答案:A.Chick2.We are going to a ________ (音乐会).3.The starfish can regenerate lost ______ (部分).4.The boy plays the ________.5.My _______ (兔子) is curious about everything.6.The __________ is a famous area known for its art.7.My uncle shares his __________ (知识) about fishing.8.The __________ (历史的轮回) reminds us of the cyclical nature of events.9.What is the term for the movement of the Earth around the sun?A. RotationB. RevolutionC. OrbitD. Spin答案: B10.Which planet is known as the Red Planet?A. EarthB. MarsC. JupiterD. Saturn答案:B11.The ______ is the path of the Earth around the sun.12.Asteroids are mostly found in the _______ belt.13.My favorite fruit is ________ (葡萄) in summer.14.The ancient city of Pompeii was buried by the eruption of ______ (维苏威火山).15.What shape has three sides?A. SquareB. TriangleC. CircleD. Rectangle答案: B16.My pet fish swims around its ______ (鱼缸).17.What do you call the process of learning and gaining knowledge?A. EducationB. RecreationC. VacationD. Celebration答案:A18.The country known for its ancient ruins and temples is ________ (以古代遗址和庙宇闻名的国家是________).19.根据图片把下列单词补充完整。

a rXiv:h ep-ph/3818v11Aug23∆→Nγ∗Coulomb Quadrupole Amplitude in pQCD Ahmad Idilbi,1,∗Xiangdong Ji,1,†and Jian-Ping Ma 2,‡1Department of physics,University of Maryland,College-Park,Maryland 20742,USA 2Institute of Theoretical Physics,Academia Sinica,Beijing,100080,P.R.China We present a leading-order pQCD calculation of the helicity-flip ∆→Nγ∗matrix element G 0(Coulomb quadrupole amplitude C 2),taking into account the transverse momenta of the quarks and the contribution from the gluons.In the large Q 2limit,its scaling behavior acquires a double-logarithmic correction log 2(Q 2/Λ2)compared with the standard scaling analysis,due to the contribution from the orbital motion of the small-x partons.Based on this and on the latest JLab experimental results of the C 2−M 1ratio R SM at Q 2=3∼4GeV 2,we make a phenomenological prediction for the latter at higher values of Q 2.I.INTRODUCTION In recent years,there have been continuing interests in the electromagnetic N →∆transition.One of the earlier interests was due to the work of Becchi and Morpurgo [1].In that work they had shown that in the context of the symmetric,non-relativistic,SU (6)quark model,the transition N →∆is a pure magnetic dipole M 1and the contribution from the electric quadrupole E 2is zero.One crucial assumption in their derivation of this ‘selection rule’is that the quarks in both the nucleon and the delta are in the zero orbital angular momentum states.These predictions were to be considered as a check to the validity of the quark model,which was still questionable in those ter experimental measurements [2]showed that,indeed,the magnetic dipole M 1contributes predominantly to the N →∆transition,while the contribution from E 2is small but non-vanishing.The non-vanishing value of E 2,and also the Coulomb quadrupole C 2in the case of a virtual photon,has generated much theoretical interest.One way to account for E 2=0is through the D -wave mixtures in the N and ∆wave functions [3].Another way is through the two-body electromagnetic currents from one-gluon and/or one-pion exchange between constituent quarks [4].In the latter case,it is argued that E 2transition is,mainly,due to a two-quark spin-flip operator.On the other hand,in the large N c limit of quantum chromodynamics it has been shown [5]that R EM ≡E 2/M 1is of order 1/N 2c.To derive this result,no assumption about orbital angular momentum of the quarks was necessary.More recent work in this direction can be found in Ref.[6].Another major issue related to the N →∆transition,and in general to any hadronic exclusive process,is the applicability of perturbative QCD (pQCD)at the range of values of momentum transfer Q 2accessible in the current generation of experiments.In terms of the ratios R EM and R SM≡C 2/M 1,pQCD power counting predicts that [7],in the limit Q 2→∞,R EM→1andR SM →const .,up to logarithmic corrections to be discussed in this paper.The former predictionhas not yet been observed experimentally.In fact,up to Q2=4GeV2,R EM stays negative and very close to zero[8,9,10,11,12].The comparison between data and pQCD prediction for R SM is the main topic of this paper.To make the pQCD predictions more relevant atfinite Q2where data have been and will be taken,one has to go beyond the asymptotic power counting,make detailed pQCD calculations of hard scattering amplitudes and derive the factorization formula for the experimental observables. In the present case,the relevant quantities are the three independent helicity matrix elements[7]:1Gλ=II.KINEMATICS AND NOTATIONIn this paper,we treat the bare delta as if it were a bound state of QCD,although in experiment it appears only as a resonance in certain scattering cross sections.Our analysis is relevant for scattering at the resonance peak where the contribution from the background vanishes by definition. We will not consider the so-called the dressing of the resonance due to the pion cloud which might be important at small Q2[11,12].Consider the following scattering:P(P N)+γ∗(q)→∆(P∆).(2) which appears as a sub-process of the electro-production of pions.We are interested in the G0 matrix element,in which case the photon is logitudinally-polarized and with a large virtuality Q2=−q2.Our analysis will be carried out in a frame in which the virtual photonγ∗,the incoming proton and the outgoing∆are collinear.The three momenta of the proton and the∆are in opposite directions and theγ∗is moving in the−z direction.The photon polarization vector is given by:ε(λ=0)=−1Q2(q3,0,0,q0).(3) with qµ=(q0,0,0,q3).We will also need the light-cone wave functions of the proton and the∆+(with the same charge as the proton).These wave functions are given by[15,17]:|P,λ=1/2 =112 d[1′][2′][3′]εijk ψ(1)∆(1′,2′,3′)× u†i↓(1′)u†j↓(2′)d†k↑(3′)+u†i↓(1′)d†j↓(2′)u†k↑(3′)+d†i↓(1′)u†j↓(2′)u†k↑(3′) |0+k′−2⊥ψ(3)∆(1′,2′,3′)(5)× u†i↓(1′)u†j↑(2′)d†k↑(3′)+u†i↓(1′)d†j↑(2′)u†k↑(3′)+d†i↓(1′)u†j↑(2′)u†k↑(3′) |0 +... where k±⊥=k x±ik y,the ellipses denote other components of the wave functions which do not enter the following calculation,and↑(↓)on the quark creation operators denotes the positive(negative) helicity of the quarks.The amplitudesψ(1)P,∆(ψ(3)P,∆,ψ(4)P)have zero(one)unit of the orbital angular momentum projection.ψ(1)∆(1,2,3)is symmetric in1and2.The integration measure is given by:d[1]d[2]d[3]=dx1dx2dx3x1x2x3d2k1⊥d2k2⊥d2k3⊥It should be noted that since the∆moves in−z direction then the orbital angular wave function must be k′−2⊥as shown in Eq.(5).The matrix element G0has two contributions:one in which the proton has l z=0and the∆carries l z=−1and in the second one the proton has l z=1 and the∆carries l z=0.For thefirst case,we introduce the hard amplitudes T i(1,2,3,1′,2′,3′), which represent three quark scattering offthe external photon with two-gluon exchange.The index i=1,2,3indicates that the photon is attached to i-th quark.For the second case,the hard amplitudes are denoted as T′i(1,2,3,1′,2′,3′),in which all quark helicities are reversed.We will explain how to compute these hard amplitudes in the next section.III.LEADING-ORDER PQCD F ACTORIZATION FORMULA FOR G0In this section,we derive a leading-order pQCD factorization formula for the helicity-flip Nγ∗→∆matrix element G0.As shown in Eq.(1),this is generated by a virtual photon with longitudinal polarization,corresponding to the Coulomb quadrupole amplitude.Thefirst step in calculating G0is to obtain the hard scattering amplitudes of partons.For this we follow the guidelines of Ref.[16].In principle,one has to consider both three-quark scattering with one unit of orbital angular momentum or three-quark-one-gluon scattering without orbital motion.Here we consider explicitly only the former and take into account the latter through the requirement of color gauge invariance,leaving out the contribution with the gluonfield strength tensor.This practice of leaving out dynamical gluon contribution corresponds to the so-called Wendzura-Wilczek approximation in the literature[18].A key point in the calculation is that since the quark masses are negligible,the quark helicity is conserved.This is due to the vectorial nature of the electromagnetic coupling between the struck quark and the virtual photon and of QCD quark-gluon coupling[14].When a Fock component of the light-cone wave function of the proton contains two quarks of the sameflavor and helicity then,clearly,it contributes only when there are two quarks of the sameflavor and helicity in the∆wave function.The exchange contribution that results due to the presence of the same two quarks has to be taken into account properly through the second quantized calculation.Using the light-cone wave functions of the proton and the∆in Eqs.(4)and(5)and keeping terms that are linear in the quark transverse momenta,one obtains:e u−e dG0=−(1)(2)(3)(4)(5)(6)(7)FIG.1:The leading pQCD diagrams contributing to the nucleon to∆transition amplitudes.The mirror diagrams should be added.Tofind the amplitudes T i,we let the outgoing quarks carry orbital angular momenta k′i⊥and theincoming quarks have zero orbital angular momenta,i.e.,k i⊥=0.From each one of the Feynmandiagrams we write the amplitude following the usual QED and QCD Feynman rules.Since thecalculation is performed in the collinear frame in which the particles are highly relativistic,wecan set the masses of the proton and the∆to zero.We expand the quark spinors in thefinalstate and the quark propagators tofirst order in the transverse momenta.Then we collect all suchcontributions from the given diagram and sum up the results of all the Feynman diagrams.Thisyields T i(k′i⊥,x i,y i,Q2).Tofind T′i(k i⊥,x i,y i,Q2)we set k′i⊥=0and k i⊥=0and follow similar steps.The results for T1(1,2,3,1′,2′,3′)at order of O(k⊥)are as follows:T1(1,2,3,1′,2′,3′)=−g4s8C2B¯x1¯y21x23y3+1¯y1¯x3x2y2x3y3+1¯x3y1y2y3x2x23w2(x1,x2,x3,y1,y2,y3)=1¯x21¯y1x3y23−1¯x21¯y1y3x2y2+1Similarly for T2we have:T2(1,2,3,1′,2′,3′)=−g4s8C2B¯x2¯y2x1x3y23+1¯x1x1y1x3y23+1¯x1¯y3y1x21x3y3.(11)To obtain T3(1,2,3,,1′,2′,3′)we interchange x1,y1,k′+1⊥and x3,y3,k′+3⊥and to obtain T′i(1,2,3,1′,2′,3′)we replace k′+i⊥with k+i⊥and interchange x i and y i.The above results are consistent with those derived in Ref.[16].To further simplify the above expressions,let us define k⊥-intergrated wave functions:φ(3)P(x1,x2,x3)=2 [d2k⊥]ψ(1)P(k1,k2,k3)φ(4)P(x1,x2,x3)=2 [d2k⊥]k3⊥·(k2⊥ψ(3)P+k1⊥ψ(4)P)(k2,k1,k3),ψ(4)P(x1,x2,x3)=2 [d2k⊥]k1⊥·(k2⊥ψ(3)P+k1⊥ψ(4)P)(k2,k1,k3)φ(3)∆(x1,x2,x3)=2 [d2k⊥]ψ(1)∆(k1,k2,k3)φ(4)∆(x1,x2,x3)=2 [d2k⊥]k3⊥·k1⊥ψ(3)∆(k2,k1,k3),ψ(4)∆(x1,x2,x3)=2 [d2k⊥]k1⊥·k1⊥ψ(3)∆(k2,k1,k3)(12) where the integration measure is defined as:[d2k⊥]=d2k1⊥d2k2⊥d2k3⊥(2M N)4Q4e u−e dwhere[dx]=dx1dx2dx3δ(1−x1−x2−x3)andαs=g2s/4π.We see from Eq.(13)that G0scales like 1/Q4in the high Q2limit,consistent with the general power counting.Tofind the normalization of G0we need to know the light-cone distribution amplitudes defined in Eq.(12).For the proton, a set of such functions have been given in Ref.[19]based on conformal expansion,QCD sum rules and Lorentz symmetry.For the∆no such work has been done explicitly.However if the∆is to be treated as a three-quark state,we believe that,at the asymptotically large Q2,the light-cone distribution amplitudes of the∆will have a y i-dependence which is identical to the x i-dependence of the light-cone distribution amplitudes of the proton[20].For the proton we have,for example, the asymptotic form ofφ(3)p is x1x2x3andφ(4)p is x1x2[13].If we perform the x i and y i integration in Eq.(13)with such functions we get,due to end-point singularities,a double logarithmic divergence results.This divergence indicates the quarks with small Feynman x contribute significantly to the hard scattering.However,for very small x for which the parton longitudinal momentum is on the order ofΛQCD,the hard scattering picture breaks down,and the above calculation is invalid.Then one has to add the so-called Feynman contribution which is relatively unimportant in the limit of large Q2.Therefore,these divergent integrals are regulated physically by a cut-offfrom below of order Λ2/Q2whereΛis some parameter that represents the soft energy scale(order of few hundreds of MeV).With this cut-off,the result of the momentum fraction integration will be a Q2-dependent term of the form,log2(Q2/Λ2).Thus we can write:G0=c′log2(Q2/Λ2)/Q4(14) where c′is a numerical factor that depends on the explicit expressions of the light-cone distribution amplitudes.With this form of G0and with the fact that G−is of order1/Q2relative to G+we will give in the next section a phenomenological prediction of the ratio R SM in the high Q2limit.IV.PHENOMENOLOGYIn the electro-production of the∆resonance,the multipoles M1,E2and C2of the exchanged virtual photon are the only ones that contribute[21,22,23,24].One of the experimentally extracted quantities related to this process is the ratio R SM≡C2/M1.In order to express this ratio in terms of the helicity matrix elements Gλwe introduce the resonance“helicity amplitudes”A1/2,A3/2and S1/2[25].These amplitudes are computed in the rest frame of the∆and the sub-indices refer to the helicity of the∆.The scalar amplitude S1/2is relevant only for virtual photons.These amplitudes are related to the helicity matrix elements through the relations[26]:A1/2=ηG+;A3/2=ηG−;S1/2=η|q|M2∆+M2N+Q22A1/2−√2A3/2(16) 7-0.3-0.2-0.10.12468101214R S M Q 2 (GeV 2)FIG.2:A phenomenological prediction for the ratio R SM .From the results of the previous section we see that A 3/2is of order 1/Q 2relative to A 1/2in the high Q 2limit and thus it will be neglected.With this approximation the ratio R SM becomes:R SM =|q |G +(17)Substituting in the last equation the expression for |q |and using Eq.(14)we get:R SM =c 2.464 2−.88log 2(Q 2/Λ2)−.88+(2.4+Q 2)2log 2(16Q 2)V.SUMMARYA perturbative QCD calculation of the helicityflip matrix element of the electromagneticN→∆transition has been given.We showed that the transverse momenta of the quarks inthe proton and∆is essential to obtain afinite result.An explicit calculation of the hard ampli-tude T i(x i,y i,k′i⊥,Q2)and T′i(x i,y i,k i⊥,Q2)has been given and the techniques of the calculationwere outlined in some detail.The essential steps of the calculation are to draw the relevant per-turbative Feynman diagrams and then to compute the contribution from each such diagram byexpanding the quark spinors and propagators tofirst power of the transverse momenta.The hardamplitudes are then to be convoluted with light-cone amplitudes.Our pQCD results for the scalingbehavior of G+,G0and G−confirm earlier scaling prediction[7].In addition we outlined how oneobtains the double logarithmic correction.Based on our result for Gλwe gave a phenomenologicalprediction for the ratio R SM.Roughly speaking,|R SM|will be of order of20%at Q2of order10 GeV2.We thank A.V.Belitsky,C.Carlson,P.Stoler,and F.Yuan for a number of useful discussions.[1] C.Becchi,G.Morpurgo,Phys.Lett.17(1965)352.[2]R.H.Dalitz,D.G.Sutherland,Phys.Rev.146(1966)1180.[3]S.S.Gershtein,G.V.Dzhikiya,Sov.J.Nucl.Phys.34(1982)870;N.Isgur,G.Karl,R.Koniuk,Phys.Rev.D25(1982)2394.[4] A.J.Buchmann,E.Hern´a ndez,A.Faessler,Phys.Rev.C55(1977)448;A.J.Buchmann,E.Hern´a ndez,K.Yazaki,Phys.Lett.B269(1991)35;Nucl.Phys.A569(1994)661.[5] E.Jenkins,X.Ji,A.Manohar,Phys.Rev.Lett.89(2002)242001.[6] A.J.Buchmann,J.A Hester,R.F Lebed,Phys.Rev.D66(2002)056002.[7] C.E.Carlson,Phys.Rev.D34(1986)2704.[8]R.Beck et al.,Phys.Rev.Lett.78(1997)606.[9] F.Kalleicher et al.,Z.Phys.A359(1997)201.[10]V.V.Frolov et al.,Phys.Rev.Lett.82(1999)45.[11]S.S.Kamalov,Shin Nan 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光照影响大型海藻英文英文回答：Light is a primary factor influencing the distribution and productivity of large seaweeds. These large algae, including kelps, laminaria, and fucus, are essential components of coastal ecosystems, providing food and habitat for a wide range of marine organisms. The availability and quality of light can significantly impact their growth, reproduction, and overall health.Light Intensity and Quality:Large seaweeds require sufficient light intensity for photosynthesis, the process by which they convert sunlight into energy. The optimal light intensity for different species varies, but most prefer well-lit environments. However, excessive light intensity can lead to photoinhibition, where the photosynthetic apparatus is damaged by high levels of radiation.Light quality, primarily determined by the wavelength, also influences seaweed growth. Certain wavelengths, such as blue and red light, are more effectively absorbed by pigments involved in photosynthesis than others. The spectral composition of light thus affects the photosynthetic efficiency and growth rate of seaweeds.Water Column Properties:The underwater light environment is influenced by several water column properties that affect light availability and penetration. These include:Water depth: As light passes through water, it is absorbed and scattered, resulting in a decrease in intensity with increasing depth.Turbidity: Suspended particles in the water, such as sediment and phytoplankton, can scatter and absorb light, further reducing its availability for seaweeds.Wave motion: Waves can cause the water column to move, resulting in variable light conditions for seaweeds.Seaweed Adaptations:Large seaweeds have evolved various adaptations to optimize their light utilization:Leaf morphology: Seaweeds often have broad, flat leaves that maximize light absorption.Pigmentation: They possess a range of photosynthetic pigments that absorb different wavelengths of light.Physiology: Seaweeds can adjust their photosynthetic rates and pigment composition based on light availability.Light and Algal Distribution:The distribution of large seaweeds is strongly influenced by light availability. They are typically found in shallow waters where light penetration is sufficient forphotosynthesis. In deeper waters or regions with high turbidity, seaweed abundance and diversity decrease.Climate Change Impacts:Climate change is projected to alter light availability and quality in coastal waters due to factors such as sea level rise, increased wave energy, and changes in water clarity. These changes could potentially affect the growth, reproduction, and distribution of large seaweeds.中文回答：光照对大型海藻的影响。

小学上册英语第5单元真题(有答案)英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1.What is the name of the famous artist who painted the Mona Lisa?A. Vincent van GoghB. Pablo PicassoC. Leonardo da VinciD. Claude Monet答案: C2.My dog loves to play in the ______ (雪).3.The _____ (绿色空间) improves urban living conditions.4.The _____ (火烈鸟) is often seen in warm, shallow waters.5. A _______ is a reaction that produces heat.6.The teacher reads _____ (stories/news) to us.7.I can see a _____ (汽车) in the street.8.The _____ (向日葵) follows the sun.9.The capital of Italy is ________.10.In a chemical reaction, energy can be absorbed in the form of _____.11.My sister's favorite _____ is a unicorn.12.The pH scale measures how __________ a solution is.13._____ (mulch) helps retain soil moisture.14.The _____ (叶子) of the tree turn yellow in autumn.15.I can ______ (dance) with my friends.16.My _____ (父母) love to travel.17.What do we call the feeling of being worried?A. JoyB. AnxietyC. HappinessD. Anger答案:B.Anxiety18.What is the name of the famous mountain range in South America?A. RockiesB. AlpsC. AndesD. Himalayas答案:c19. A lion is called the _______ of the jungle.20.I enjoy studying ______ (科学) to understand the world better.21.The sparrow builds its _______ (巢) in trees.22.My ___ (小狗) is always happy to see me.23. A __________ is a large expanse of tundra.24.The girl is very ________.25.I can customize my ________ (玩具名称) however I want.26.I have _____ (three/four) apples in my bag.27. A _____ (vine) grows along fences.28.The bat uses _______ (回声定位) to navigate.29.The main gas used in welding is __________.30.The discovery of ________ has had a profound impact on environmental science.31.The ancient Romans used ________ for voting.32. A _______ describes how easily an element can lose electrons.33.After a while, I reached the park. There were many people ______ (4) and having fun. Some children were playing on the swings, while others were flying ______ (5). I found a nice spot under a tree to sit and enjoy my snacks. While I was resting, I34.I read a _____ (书) every night.35.The kitten is ___ on the couch. (sitting)36.The bird flies in the ______.37. A telescope helps us see ______ in the sky.38.I enjoy ______ my favorite games on weekends. (playing)39.I have _____ (homework) to do.40.The baby is _____ (crying/sleeping) in the crib.41.I like to _______ (watch) the stars at night.42.What is 8 - 3?A. 4B. 5C. 6D. 7答案:B 543.The ______ teaches us about biology.44.My favorite holiday is ________ (情人节) with friends.45.The __________ (社会变革) can improve lives.46.The main ingredient in bleach is ______.47. Carta was signed in _____. The Magn48.What do you call the art of making pottery?A. CeramicsB. SculptureC. PaintingD. Weaving答案: A49.The temperature at which a gas condenses into a liquid is its ______ point.50.The apple is ______ and juicy. (red)51. A ________ (蟒蛇) can grow very long and is often found in jungles.52.My sister and I have a toy ____ collection. (玩具名称)53.I can draw inspiration from my ________ (玩具).54. A garden can attract various ______ (昆虫).55.My mom loves __________ (社区服务).56.Tectonic plates can move apart, collide, or slide past each other, leading to ______.57.Chemical reactions often require a change in ________ to occur.58.My aunt has a beautiful __________. (花园)59.The chemical formula for acetylene is _____.60.I can play games with my ________ (玩具).61.The chemical symbol for calcium is ________.62.What is the tallest building in the world?A. Empire State BuildingB. Burj KhalifaC. CN TowerD. Willis Tower答案:B63.The fastest land animal is the __________.64.The ______ (海狮) is often seen on rocky shores.65._____ (草本植物) are used in many recipes.66.The __________ (植物的适应) mechanisms are amazing to observe.67.What do we call the process of dividing a cell into two daughter cells?A. MitosisB. MeiosisC. Cell divisionD. Cytokinesis答案:A68.The chemical formula for sodium chloride is ________.69. A light year measures ______ in space.70.The ________ (candy) is sweet and colorful.71.Carbon dioxide is produced during _____ respiration.72.The _______ of an object can be affected by the force applied to it.73.Christopher Columbus discovered America in ______ (1492年).74.The ______ of an element is determined by the number of protons.75.Space shuttles were used to transport astronauts to and from _______.76. A sheep provides us with ________________ (羊毛).77.听一听，判断所听内容与图片是否相符。

物理专业名词Unit 1integrated circuit （ IC）集成电路chemistry textbook元素周期表Ideal operational amplifier （ op amp）理想运算放大器bipolar-junction transistor （ BJT）双极结型晶electronics体管电子学diode 二极管analog signal 模拟信号digital signalfield-effect transistor（ FET）场效应管数字信号voltage gaintransistor 晶体管电压增压light emitting diode （ LED）发光二极管bandwidth 带宽closed-loop gain 闭环增益flip-flop触发器supply voltage 电源电压metal-oxide semiconductor （ MOS）金属氧化power dissipation功率耗费物半导体resistance 电阻complementary-MOS 互补型impedance 阻抗base 基极bias currents 偏置电流emitter发射极frequency response 频次响应collector集电极phase shift 相移gate 栅极transient response瞬态响应drain 漏极distortion 失真source 源极common-mode rejection 共模克制Unit 3open-loop gain 开环增益EM (全写 Electromagnetic) filed 电磁场voltage 电压net EM filed 净电磁场direct current （ DC）直流电wireless communications无线通讯alternating current（ AC）沟通电physical filed 物理场current 电流gravitation wan万有引力transducer 传感器the weak/strong interactiondata sheet 技术规格表弱 / 强互相作用offset voltage drift赔偿电压漂移electric filed 电场frequency 频次magnetic filed磁场Unit 2stationary/moving charges静止 / 运动电荷Maxwell ’sequations 麦克斯韦方程组Lorentz force law洛伦兹力定律quantum mechanical量子力学radio transmitter无线电发射机metal atoms金属原子radiation of low frequency低频辐射ultraviolet catastrophe紫外灾害a fixed frequency固定频次Max Planck 普朗克常量the photoelectric effect光电效应a quantum electrodynamics量子电动力学the grayitational filed of the sun太阳重力场Unit 4electronic transmitter电子发射机public telephone networks公共电话网gross world product世界总产值mobile phone移着手机radio broadcast 无线电广播free space 自由空间point-to-point communication 点对点通讯analogue/digital signals 模拟 / 数字信号streams of information 信息流time-division multiplexing时分多路技术（TDM）amplitude-shift keying振幅键控amplitude modulation幅度调制frequency modulation频次调制Unit 5Multiple Access Techniques 多址接入技术frequency spectrum频谱fixed bandwidth固定带宽FDMA(Frequency Division Multiple Access)频分多址TDMA(Time Division Multiple Access)时分多址CDMA(Code Division Multiple Access)码分多址radio spectrum无线电频谱wireless network无线网络base station基站analog transmissions模拟通讯available bandwidth可用带宽analog signals模拟信号multipath effects多径效应inter-symbol interference码间串扰Global System for Mobile Communications 全世界挪动通讯系统spread spectrum technique扩频技术pseudo random noise code(PN 码 )伪随机噪声信号correlate卷积phase-shift keying 相移键控accurate ranging精确测距frequency-shift keying频移键控multipath tolerance多径适应性LSI(Large Scale Integrated circuit)大规模集成电路VLSI(Very Large Scale Integration）超大规模集成电路process gain办理增益signal to noise信噪比bit rate比特率background noise背景噪声wide spread interference宽(扩)频扰乱chip码片synchronization同步forward link encoding前向连 (链)接编码matrix矩阵reverse link encoding反向链接编码time slot时隙unit6mobile communications挪动通讯cellular phones蜂窝电话cellular system蜂窝系统cordless phones无绳电话Radio Frequency(RF)射频transceiver收发器terminal终端the wireless infrastructure无线基础设备forward channel前向信道downlink下行链路reverse channel逆向信道uplink上行链路FM(frequency modulation)调频carrier frequency载波频次frequency reuse频次复用MTSO(mobile telephone switching office)挪动电话互换机构co-channel interference共信道扰乱handoff切换roams遨游path loss and multipath fading路径消耗和多径虚弱phase shifts相移amplitudes幅值space diversity空间分集antenna diversity天线分集non-faded signal无虚弱信号frequency diversity频次分集time diversity时间分集delay spread延缓扩展attenuation衰减absorption coefficient汲取系数RMS(Root-Mean-Square)均方根microsecond微秒kilohertz千赫digital modulating waveform数字调制波形interleaving交叉signal processing techniques信号办理技术bit stream比特流物理专业名词Unit7Satellite Communications卫星通讯Communications Satellite通讯卫星Commercial satellite商业卫星artificial satellite人造卫星television broadcasting电视广播radio broadcasting无线电广播wide-area network communications广域网络通讯point-to-point点对点wireless local area network无线局域网络Earth orbit地球轨道amateur radio communications业余无线通信weather forecasting天气预告Global Positioning System (GPS) 全世界定位系统hand-held terminals手持终端fixed-point telephone固定电话distance learning远程教课hand held telephone (cellular phone)手持电话cable channel有线电视频道Direct Broadcast Satellite(DBS) 直播卫星central control unit中央控制单元Fixed Service Satellite （ FSS）固定服务的卫星Tele Vision Receive Only (TVRO)仅电视接收DTHHBO家庭影院NASA 国家航空航天局low Earth orbit低地轨道space-borne repeaters太空中继器satellite broadband卫星宽带data-forwarding services数据转发业务dialup connection拨号上网wireline broadband有线宽带网络附录二conver optimization凸优化mathematical optimization数学优化least-squares 最小二乘法linear programming线性规划nonlinear-programming非线性规划interior-point method内点法semidefinite program半正定规划second-order cone program二阶锥规划automatic control system自动控制系统signal processing信号办理electronic circuit design电子技术课程设计combinatorial optimization组合优化global optimization整体最正确化real-time及时computer-aided计算机协助real-time reactive及时无功radio frequency无线射频associated dual 双有关系linear polarization线性极化singular value 奇怪值self-concordance自稳固trade-off折中方案data mining 数据发掘Architecture is deployed部署架构elementary topology 失散拓谱cross-layer跨层complexity analysis复杂度剖析Optimization优化theoretically oriented ）或理论化demonstrate证明附录一protocol framework协议框架Wireless device无线设备Physical quantity 物理量cellular phone蜂窝电话radio frequency(RF)射频Personal digital assistantimage sensor图像传感器（ PDA）个人数码助手extract data提取数据Energy-efficient高能效的macrosensor巨传感器portable device便携式设备Geophone sensor 地震检波传感器Real-time multimediahelicopter直升机communication及时多媒体通讯bulldozer推土机Medical application医学应用Fault-tolerant容错性Wireless Microsensor networkredundancy冗余性无线微传感器网络infrastructure基础设备home networking家庭组网Machine failure diagnosis机器故障诊疗Bandwidth带宽chemical/biological detection 生化检测restriction限制；拘束Medical monitoring医学监控innovative改革的，创新的deplete耗尽Protocol 协议Energy dissipation能量耗费tether紧的algorithm算法uniformity一致inherent固有的；内在的；Ad-hoc自组织的time-varying时变self-configuring自配置High Performance高性能global control全局控制worst-case最坏状况Retrieve检索latency时延by a factor of........的几倍Lossy compression有损压缩overhead开支Incorporate汲取data dissemination数据流传extraneous外来的Sophisticated复杂的cluster簇multi-hop routing多跳路由Correlation有关性latency-aware延时敏感cognitive认识Application-specific应用有关的application-level应用层Collaborate合作rotation轮换formation生成in terms of在什么方面Internal component内部组件compress压缩autonomous自动的Magnitude increase数目级增加error-prone易于犯错The 3rd generation(3G)Global system for mobile communication(GSM) 全世界挪动通讯系统Six-fold 6 倍Discrete cosine transform （ DCT）失散余弦变换。