A Possible Fixed Target Programme for the Polarized HERA Proton Ring

ITER百科名片ITER国际热核聚变实验堆（ITER）计划是当今世界最大的大科学工程国际科技合作计划之一，也是迄今我国参加的规模最大的国际科技合作计划。

ITER计划吸引了包括中国、欧盟、印度、日本、韩国、俄罗斯和美国等世界主要核国家和科技强国共同参与。

目录[隐藏]来源发展现况意义[编辑本段]来源经过近5 年的艰苦谈判，2006 年11 月21 日在法国爱丽舍宫，参与ITER 计划的ITER谈判七方共同签署了《联合实施国际热核聚变实验堆计划建立国际聚变能组织协定》和《联合实施国际热核聚变实验堆计划建立国际聚变能组织特权和豁免协定》以及其他相关文件。

至此，ITER计划谈判圆满结束。

12 月1 日ITER 临时国际组织成立，ITER 计划正式开始实施。

[编辑本段]发展ITER是International Thermonuclear Experimental Reactor的简写，全称国际热核聚变实验反应堆，也被人们形象地称为人造太阳，地点设在法国的南部小城卡达拉舍。

为欧盟、美国、中国、日本、韩国、印度和俄罗斯等七方共同参与。

中国政府宣布投入10亿美元参与ITER计划的运作，这是迄今中国投入最大的国际大科学工程。

参与该计划研究工作的包括中国科学院等离子体物理研究所、核工业西南物理研究院等中国研究机构。

2008年10月10日，科学技术部隆重举行中国国际核聚变能源计划执行中心揭牌仪式。

出席仪式的有全国人大外事委、外交部、发改委、教育部、财政部、国防科工局、中科院、工程院、核工业集团公司、国家自然科学基金会等部门、单位代表和工业界的代表；ITER组织总干事、副总干事、ITER组织成员国驻华外交官，国家磁约束核聚变专家委员会成员和顾问，以及国内相关科研院所的代表。

科技部万钢部长在仪式上讲话，强调了我国参加ITER计划和做好ITER计划工作的重要意义，要求执行中心不辜负国家的重托，努力工作，建立符合参与大型国际科学工程和研究合作项目要求的、职责分明、运转高效的决策、咨询和管理系统，保障各方面任务的顺利开展和实施。

【初中地理】开普勒452b成为寻找地外生命的新目标艺术家描绘的Kepler 452b行星环绕Kepler 452恒星运行，它距离地球1400光年。

据国外媒体报道，目前，搜寻地外文明研究所的科学家开始将地球“孪生兄弟”Kepler 452b作为重点勘测目标，试图发现外星生命迹象。

Kepler 452b是首颗类似地球大小的系外行星，位于类似太阳的恒星系统中的宜居地带。

近日，美国宇航局宣称发现Kepler 452b，认为它是太阳系之外最近似“地球2.0”的系外行星，研究人员使用艾伦望远镜阵列研究该行星的无线信号，从而识别地外智慧生命存在的迹象。

搜寻地外文明研究所资深天文学家塞斯-肖斯塔克(Seth Shostak)说：“我们没有理由对搜寻地外文明感到气馁!”Kepler 452是一颗类似太阳的恒星，距离地球1400光年，位于天鹅星座，最新发现的Kepler 452b行星直径大约是地球的1.6倍，证实其成分构成的质量和密度仍是一个挑战。

研究报告第一作者、美国宇航局艾姆斯研究中心的乔-詹金斯(Jon Jenkins)说：“我们很想直接测量它的质量，从而能够勘测出密度，这是分析它是一颗岩石行星、富水行星或者气态行星的重要线索。

”研究人员依赖统计数据显示，Kepler 452b具有类似地球成分的概率为50%。

基于它的体积、轨道和主恒星，这颗行星是迄今发现最接近地球的星球。

Kepler 452b环绕恒星运行一周需要385天，比地球公转周期长3个周期。

该行星位于恒星宜居地带，Kepler 452b表面可以维持液态水的存在。

水被认为是生命进化的重要元素，因此Kepler 452b是迄今发现最有可能潜藏外星人的系外行星。

肖斯塔克和詹金斯强调称，Kepler 452b具有真实重要性是因为这将表明太阳系之外广泛存在着系外行星。

在发现Kepler 452b之前，科学家并未发现在类似太阳的恒星系统中存在宜居地带，希望统计数据表明许多类似行星环绕着其它恒星，但并未使用现代天文设备进行观测。

a r X i v :h e p -p h /9711228v 1 4 N o v 1997hep-ph/9711228October 1997O (α)QED Corrections to Polarized Elastic µe and Deep Inelastic lN ScatteringDima Bardin a,b,c ,Johannes Bl¨u mlein a ,Penka Christova a,d ,and Lida Kalinovskaya a,caDESY–Zeuthen,Platanenallee 6,D–15735Zeuthen,GermanybINFN,Sezione di Torino,Torino,ItalycJINR,ul.Joliot-Curie 6,RU–141980Dubna,RussiadBishop Konstantin Preslavsky University of Shoumen,9700Shoumen,BulgariaAbstractTwo computer codes relevant for the description of deep inelastic scattering offpolarized targets are discussed.The code µe la deals with radiative corrections to elastic µe scattering,one method applied for muon beam polarimetry.The code HECTOR allows to calculate both the radiative corrections for unpolarized and polarized deep inelastic scattering,including higher order QED corrections.1IntroductionThe exact knowledge of QED,QCD,and electroweak (EW)radiative corrections (RC)to the deep inelastic scattering (DIS)processes is necessary for a precise determination of the nucleon structure functions.The present and forthcoming high statistics measurements of polarized structure functions in the SLAC experiments,by HERMES,and later by COMPASS require the knowledge of the RC to the DIS polarized cross-sections at the percent level.Several codes based on different approaches for the calculation of the RC to DIS experiments,mainly for non-polarized DIS,were developped and thoroughly compared in the past,cf.[1].Later on the radiative corrections for a vast amount of experimentally relevant sets of kinematic variables were calculated [2],including also semi-inclusive situations as the RC’s in the case of tagged photons [3].Furthermore the radiative corrections to elastic µ-e scattering,a process to monitor (polarized)muon beams,were calculated [4].The corresponding codes are :•HECTOR 1.00,(1994-1995)[5],by the Dubna-Zeuthen Group.It calculates QED,QCD and EW corrections for variety of measuremets for unpolarized DIS.•µe la 1.00,(March 1996)[4],calculates O (α)QED correction for polarized µe elastic scattering.•HECTOR1.11,(1996)extends HECTOR1.00including the radiative corrections for polarized DIS[6],and for DIS with tagged photons[3].The beta-version of the code is available from http://www.ifh.de/.2The Programµe laMuon beams may be monitored using the processes ofµdecay andµe scattering in case of atomic targets.Both processes were used by the SMC experiment.Similar techniques will be used by the COMPASS experiment.For the cross section measurement the radiative corrections to these processes have to be known at high precision.For this purpose a renewed calculation of the radiative corrections toσ(µe→µe)was performed[4].The differential cross-section of polarized elasticµe scattering in the Born approximation reads,cf.[7],dσBORNm e Eµ (Y−y)2(1−P e Pµ) ,(1)where y=yµ=1−E′µ/Eµ=E′e/Eµ=y e,Y=(1+mµ/2/Eµ)−1=y max,mµ,m e–muon and electron masses,Eµ,E′µ,E′e the energies of the incoming and outgoing muon,and outgoing electron respectively,in the laboratory frame.Pµand P e denote the longitudinal polarizations of muon beam and electron target.At Born level yµand y e agree.However,both quantities are different under inclusion of radiative corrections due to bremsstrahlung.The correction factors may be rather different depending on which variables(yµor y e)are used.In the SMC analysis the yµ-distribution was used to measure the electron spin-flip asymmetry A expµe.Since previous calculations,[8,9],referred to y e,and only ref.[9]took polarizations into account,a new calculation was performed,including the complete O(α)QED correction for the yµ-distribution,longitudinal polarizations for both leptons,theµ-mass effects,and neglecting m e wherever possible.Furthermore the present calculation allows for cuts on the electron re-coil energy(35GeV),the energy balance(40GeV),and angular cuts for both outgoing leptons (1mrad).The default values are given in parentheses.Up to order O(α3),14Feynman graphs contribute to the cross-section forµ-e scattering, which may be subdivided into12=2×6pieces,which are separately gauge invariantdσQEDdyµ.(2) One may express(2)also asdσQEDdyµ+P e Pµdσpol kk=1−Born cross-section,k=b;2−RC for the muonic current:vertex+bremsstrahlung,k=µµ;3−amm contribution from muonic current,k=amm;4−RC for the electronic current:vertex+bremsstrahlung,k=ee;5−µe interference:two-photon exchange+muon-electron bremsstrahlung interference,k=µe;6−vacuum polarization correction,runningα,k=vp.The FORTRAN code for the scattering cross section(2)µe la was used in a recent analysis of the SMC collaboration.The RC,δA yµ,to the asymmetry A QEDµeshown infigures1and2is defined asδA yµ=A QEDµedσunpol.(4)The results may be summarized as follows.The O(α)QED RC to polarized elasticµe scattering were calculated for thefirst time using the variable yµ.A rather general FORTRAN codeµe la for this process was created allowing for the inclusion of kinematic cuts.Since under the conditions of the SMC experiment the corrections turn out to be small our calculation justifies their neglection. 3Program HECTOR3.1Different approaches to RC for DISThe radiative corrections to deep inelastic scattering are treated using two basic approaches. One possibility consists in generating events on the basis of matrix elements including the RC’s. This approach is suited for detector simulations,but requests a very hughe number of events to obtain the corrections at a high precision.Alternatively,semi-analytic codes allow a fast and very precise evaluation,even including a series of basic cuts andflexible adjustment to specific phase space requirements,which may be caused by the way kinematic variables are experimentally measured,cf.[2,5].Recently,a third approach,the so-called deterministic approach,was followed,cf.[10].It treats the RC’s completely exclusively combining features of fast computing with the possibility to apply any cuts.Some elements of this approach were used inµe la and in the branch of HECTOR1.11,in which DIS with tagged photons is calculated.Concerning the theoretical treatment three approaches are in use to calculate the radiative corrections:1)the model-independent approach(MI);2)the leading-log approximation(LLA); and3)an approach based on the quark-parton model(QPM)in evaluating the radiative correc-tions to the scattering cross-section.In the model-independent approach the QED corrections are only evaluated for the leptonic tensor.Strictly it applies only for neutral current processes.The hadronic tensor can be dealt with in its most general form on the Lorentz-level.Both lepton-hadron corrections as well as pure hadronic corrections are neglected.This is justified in a series of cases in which these corrections turn out to be very small.The leading logarithmic approximation is one of the semi-analytic treatments in which the different collinear singularities of O((αln(Q2/m2l))n)are evaluated and other corrections are neglected.The QPM-approach deals with the full set of diagrams on the quark level.Within this method,any corrections(lepton-hadron interference, EW)can be included.However,it has limited precision too,now due to use of QPM-model itself. Details on the realization of these approaches within the code HECTOR are given in ref.[5,11].3.2O (α)QED Corrections for Polarized Deep Inelastic ScatteringTo introduce basic notation,we show the Born diagramr rr r j r r r r l ∓( k 1,m )l ∓( k 2,m )X ( p ′,M h )p ( p ,M )γ,Z ¨¨¨¨B ¨¨¨¨£¢ ¡£¢ ¡£¢ ¡£¢ ¡£¢ ¡£¢ ¡£¢ ¡£¢ ¡£¢ ¡£¢ ¡z r r r r r r r r r r r r r rr ¨¨¨¨B ¨¨¨¨r r r r j r r r r and the Born cross-section,which is presented as the product of the leptonic and hadronic tensordσBorn =2πα2p.k 1,x =Q 2q 2F 1(x,Q 2)+p µ p ν2p.qF 3(x,Q 2)+ie µνλσq λs σ(p.q )2G 2(x,Q 2)+p µ s ν+ s µ p νp.q1(p.q )2G 4(x,Q 2)+−g µν+q µq νp.qG 5(x,Q 2),(8)wherep µ=p µ−p.qq 2q µ,and s is the four vector of nucleon polarization,which is given by s =λp M (0, n )in the nucleonrest frame.The combined structure functions in eq.(8)F1,2(x,Q2)=Q2e Fγγ1,2(x,Q2)+2|Q e|(v l−p eλl a l)χ(Q2)FγZ1,2(x,Q2)+ v2l+a2l−2p eλl v l a l χ2(Q2)F ZZ1,2(x,Q2),F3(x,Q2)=2|Q e|(p e a l−λl v l)χ(Q2)FγZ3(x,Q2),+ 2p e v l a l−λl v2l+a2l χ2(Q2)F ZZ3(x,Q2),G1,2(x,Q2)=−Q2eλl gγγ1,2(x,Q2)+2|Q e|(p e a l−λl v l)χ(Q2)gγZ1,2(x,Q2),+ 2p e v l a l−λl v2l+a2l χ2(Q2)g ZZ1,2(x,Q2),G3,4,5(x,Q2)=2|Q e|(v l−p eλl a l)χ(Q2)gγZ3,4,5(x,Q2),+ v2l+a2l−2p eλl v l a l χ2(Q2)g ZZ3,4,5(x,Q2),(9) are expressed via the hadronic structure functions,the Z-boson-lepton couplings v l,a l,and the ratio of the propagators for the photon and Z-bosonχ(Q2)=Gµ2M2ZQ2+M2Z.(10)Furthermore we use the parameter p e for which p e=1for a scattered lepton and p e=−1for a scattered antilepton.The hadronic structure functions can be expressed in terms of parton densities accounting for the twist-2contributions only,see[12].Here,a series of relations between the different structure functions are used in leading order QCD.The DIS cross-section on the Born-leveld2σBorndxdy +d2σpol Borndxdy =2πα2S ,S U3(y,Q2)=x 1−(1−y)2 ,(13) and the polarized partdσpol BornQ4λp N f p S5i=1S p gi(x,y)G i(x,Q2).(14)Here,S p gi(x,y)are functions,similar to(13),and may be found in[6].Furthermore we used the abbrevationsf L=1, n L=λp N k 12πSy 1−y−M2xy2π1−yThe O(α)DIS cross-section readsd2σQED,1πδVRd2σBorndx l dy l=d2σunpolQED,1dx l dy l.(16)All partial cross-sections have a form similar to the Born cross-section and are expressed in terms of kinematic functions and combinations of structure functions.In the O(α)approximation the measured cross-section,σrad,is define asd2σraddx l dy l +d2σQED,1dx l dy l+d2σpol radd2σBorn−1.(18)The radiative corrections calculated for leptonic variables grow towards high y and smaller values of x.Thefigures compare the results obtained in LLA,accounting for initial(i)andfinal state (f)radiation,as well as the Compton contribution(c2)with the result of the complete calculation of the leptonic corrections.In most of the phase space the LLA correction provides an excellent description,except of extreme kinematic ranges.A comparison of the radiative corrections for polarized deep inelastic scattering between the codes HECTOR and POLRAD[17]was carried out.It had to be performed under simplified conditions due to the restrictions of POLRAD.Corresponding results may be found in[11,13,14].3.3ConclusionsFor the evaluation of the QED radiative corrections to deep inelastic scattering of polarized targets two codes HECTOR and POLRAD exist.The code HECTOR allows a completely general study of the radiative corrections in the model independent approach in O(α)for neutral current reac-tions including Z-boson exchange.Furthermore,the LLA corrections are available in1st and2nd order,including soft-photon resummation and for charged current reactions.POLRAD contains a branch which may be used for some semi-inclusive DIS processes.The initial state radia-tive corrections(to2nd order in LLA+soft photon exponentiation)to these(and many more processes)can be calculated in detail with the code HECTOR,if the corresponding user-supplied routine USRBRN is used together with this package.This applies both for neutral and charged current processes as well as a large variety of different measurements of kinematic variables. Aside the leptonic corrections,which were studied in detail already,further investigations may concern QED corrections to the hadronic tensor as well as the interference terms. References[1]Proceedings of the Workshop on Physics at HERA,1991Hamburg(DESY,Hamburg,1992),W.Buchm¨u ller and G.Ingelman(eds.).[2]J.Bl¨u mlein,Z.Phys.C65(1995)293.[3]D.Bardin,L.Kalinovskaya and T.Riemann,DESY96–213,Z.Phys.C in print.[4]D.Bardin and L.Kalinovskaya,µe la,version1.00,March1996.The source code is availablefrom http://www.ifh.de/~bardin.[5]A.Arbuzov,D.Bardin,J.Bl¨u mlein,L.Kalinovskaya and T.Riemann,Comput.Phys.Commun.94(1996)128,hep-ph/9510410[6]D.Bardin,J.Bl¨u mlein,P.Christova and L.Kalinovskaya,DESY96–189,hep-ph/9612435,Nucl.Phys.B in print.[7]SMC collaboration,D.Adams et al.,Phys.Lett.B396(1997)338;Phys.Rev.D56(1997)5330,and references therein.[8]A.I.Nikischov,Sov.J.Exp.Theor.Phys.Lett.9(1960)757;P.van Nieuwenhuizen,Nucl.Phys.B28(1971)429;D.Bardin and N.Shumeiko,Nucl.Phys.B127(1977)242.[9]T.V.Kukhto,N.M.Shumeiko and S.I.Timoshin,J.Phys.G13(1987)725.[10]G.Passarino,mun.97(1996)261.[11]D.Bardin,J.Bl¨u mlein,P.Christova,L.Kalinovskaya,and T.Riemann,Acta Phys.PolonicaB28(1997)511.[12]J.Bl¨u mlein and N.Kochelev,Phys.Lett.B381(1996)296;Nucl.Phys.B498(1997)285.[13]D.Bardin,J.Bl¨u mlein,P.Christova and L.Kalinovskaya,Preprint DESY96–198,hep-ph/9609399,in:Proceedings of the Workshop‘Future Physics at HERA’,G.Ingelman,A.De Roeck,R.Klanner(eds.),Vol.1,p.13;hep-ph/9609399.[14]D.Bardin,Contribution to the Proceedings of the International Conference on High EnergyPhysics,Warsaw,August1996.[15]M.Gl¨u ck,E.Reya,M.Stratmann and W.Vogelsang,Phys.Rev.D53(1996)4775.[16]S.Wandzura and F.Wilczek,Phys.Lett.B72(1977)195.[17]I.Akushevich,A.Il’ichev,N.Shumeiko,A.Soroko and A.Tolkachev,hep-ph/9706516.-20-18-16-14-12-10-8-6-4-200.10.20.30.40.50.60.70.80.91elaFigure 1:The QED radiative corrections to asymmetry without experimental cuts.-1-0.8-0.6-0.4-0.200.20.40.60.810.10.20.30.40.50.60.70.80.91elaFigure 2:The QED radiative corrections to asymmetry with experimental cuts.-50-40-30-20-100102030405000.10.20.30.40.50.60.70.80.91HectorFigure 3:A comparison of complete and LLA RC’s in the kinematic regime of HERMES for neutral current longitudinally polarized DIS in leptonic variables.The polarized parton densities [15]are used.The structure function g 2is calculated using the Wandzura–Wilczek relation.c 2stands for the Compton contribution,see [6]for details.-20-100102030405000.10.20.30.40.50.60.70.80.91HectorFigure 4:The same as in fig.3,but for energies in the range of the SMC-experiment.-20-10010203040500.10.20.30.40.50.60.70.80.91HectorFigure 5:The same as in fig.4for x =10−3.-200-150-100-5005010015020000.10.20.30.40.50.60.70.80.91HectorFigure 6:A comparison of complete and LLA RC’s at HERA collider kinematic regime for neutral current deep inelastic scattering offa longitudinally polarized target measuring the kinematic variables at the leptonic vertex.。

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In this part, there are 20 incomplete sentences. Below each sentence, there are four words or phrases respectively marked by letters A, B, C and D. Choose the word or phrase which best completes each sentence. There is only one right answer. ）第1题It was from the Lowell Laboratory that the ninth________, Pluto, was sighted in 1930.A planetB constellationC stardomD satellite【正确答案】：A 【本题分数】：1.0分【答案解析】近义辨析。

A ．planet 行星(尤指太阳系)；B ．constellation 恒星群，星座；C ．stardom 明星的身份，演员们；D ．satellite 人造卫星，又知Pluto 是冥王星；答案应为A 。

第2题The rodent, ________the mouse, rat, guinea pig, and porcupine, are mammals with incisor-like teeth in both jaws.A made upB includingC consistingD constitute【正确答案】：B【本题分数】：1.0分【答案解析】模考吧网提供最优质的模拟试题，最全的历年真题，最精准的预测押题！近义辨析。

1宇航员芭比娃娃首亮相鼓励女性从事科学职业中等说明文新闻报道Samantha Cristoforetti turns 42 this year. She is one of the world’s few active female astronauts. She has been in space for 199 days and 16 hours. But sadly, she is the only Italian female member of the European Space Agency now.To set a good example for young girls, the ESA is working with Barbie. Two new Barbie dolls have been made based on Cristoforetti’s looks. One of them wears a NASA’s spacewalking suit. The other is dressed in a blue flight suit with ESA patches.The Cristoforetti Barbie is part of the Barbie Dream Gap Project which started in 2018. It aims to encourage more girls to explore careers in STEM-related fields. STEM means in science, technology, engineering, and maths. The Italian astronaut will also make a video program to show young audiences around the ESA. Cristoforetti hopes to help them dream about their future without limits. After all, anything boys can do, girls can do better.“We know how important it is for girls to have role models and this new ESA collaboration helps us to take this to an astronomical new level,” an official from Barbie said.1 . How many female Italian astronauts are there in ESA?A 0.B 1.C 2.D 3.2 . Why does the ESA work with Barbie?A To encourage girls to study STEM.B To encourage girls to have their dreams.C To train more female astronauts.D To set a good example for young girls.3 . What is the color of the Barbie’s flight suit?A Orange.B White.C Blue.D Red.4 . What does the underlined word “collaboration” mean in Chinese?A 工作.B 合作.C 接洽.D 模型.5 . What is the best title for this passage?A Two astronaut Barbie dolls have been made.B The only Italian female astronaut in ESA.C To encourage more girls to dream with no limit.D Barbie models based on Italian female astronaut.2纳达尔4夺美网冠军，大满贯19冠直追费德勒中等记叙文文娱体育The match was finally over. A tired Rafael Nadal from Spain flopped down on the ground. The crowd in the stadium all stood up to cheer.The 33-year-old man had just beaten Daniil Medvedev who is ten years younger than him. He had won his fourth U.S. Open title. It was also his 19th grand slam title. The match was a hard one. It lasted nearly five hours — the second-longest final in Nadal’s career.Emotions were already running high. After a video of Nadal’s career was shown in the stadium, the cheers became louder. Nadal, at last, could not hold back his tears. “The emotions are sometimes hard to control,” he said. “All those cheers make this night unforgettable for me.”When he reflected on his latest win, Nadal still appeared humble. He said his family and team had helped him a lot.Now, Nadal is just one grand slam title away from Roger Federer, who hold the first position in tennis. Is he thinking about overtaking the Swiss star? The answer is “No”. “I cannot always think about getting more and more. I just try to do it my way. I’m happy about the career I have,” Nadal said.1 . How old is Daniil Medvedev?A 10 years old.B 23 years old.C 33 years old.D 43 yearsold.2 . What does the underlined word “humble” mean in Chinese?A 骄傲的.B 高兴的.C 悲伤的.D 谦虚的.3 . How many grand slam titles has Roger Federer won?A 4.B 18.C 19.D 20.4 . What can we learn from this passage?A Nadal knew he would win the game before it started.B Nadal is one of the best tennis player in the world.C Nadal will try to get more slams.D Nadal will retire after the game.5 . What is the main idea of this passage?A A new super star in tennis.B The modest tennis super star.C An unforgettable match for Nadal.D Nadal won the 19th grand slam.3法国“飞人”扎帕塔成功飞越英吉利海峡容易记叙文逸闻趣事Do you dream of flying? French inventor Franky Zapata did so. Last month, he made history as the first person to “fly” across the English Channel by a hoverboard.Zapata took off from Sangatte on France’s northern coast and touched down near Dover, England. His hoverboard was powered by a backpack full of fuel. It kept him in the air for ten minutes. Then Zapata stopped halfway on a boat to fill his backpack with fuel again. It took him just 22 minutes to complete the 35-kilometer journey. The crowd clapped loudly as they saw him reach Britain safely. Zapata said that it was the most amazing moment in his life.The French inventor has been working on his hoverboard for three years. He did not think of giving up even after losing two of his fingers in an accident. Zapata is now considering creating a flying car. Do you look forward to it?1 . Where did Zapata fly across?A The English Channel.B France’s northern coast.C Dover, England.D Paris, France.2 . How long did it take Zapata to complete the journey?A Half an hour.B 35 minutes.C Ten minutes.D 22 minutes.3 . What happened to Zapata according to Paragraph Three?A He gave up creating a flying car.B He lost two of his fingers.C A traffic accident happened to him.D He lost his two feet.4 . What’s the Chinese meaning of the underlined word “halfway”?A 又一次.B 在中间.C 中途.D 大致上.5 . Which of the following is NOT true according to the passage?A Zapata is a French.B Zapata’s hoverboard was powered by a backpack.C Zapata reached Britain safely.D Zapata is creating a flying car now.42022北京冬奥会和冬残奥会吉祥物“冰墩墩”和“雪容融”正式亮相容易说明文热点话题1 . When will the 2022 Winter Paralympics start?A On 4th March, 2022.B On 4th January, 2022.C On 4th February, 2022.D On 4th February, 2023.2 . What does Bing Dwen Dwen look like?A A child.B A lantern.C An astronaut.D A sports track.3 . Where is the red heart?A It’s on Shuey Rhon Rhon’s face.B It’s on Bing Dwen Dwen’s neck.C It’s on Shuey Rhon Rhon’s lantern.D It’s on Bing Dwen Dwen’s left palm.4 . What’s on Shuey Rhon Rhon’s head?A Paper cuttings of doves.B Paper cuttings of pandas.C Bright colours of the circles.D Chinese characters of Olympics.5 . What is the main idea of this passage?A The 2022 Winter Olympic games are coming.B The 2022 Winter Olympic games will be held in Beijing.C Let’s see mascots of the 2022 Winter Olympics and Paralympics.D Chinese culture will be used in 2022 Winter Olympic games.5飞行奇遇记：乘客顶替机长把飞机开走了！中等记叙文逸闻趣事An off-duty pilot was honoured as a “legend” after stepping in to fly a plane himself to stop the flight being cancelled.Michael Bradley, a qualified EasyJet pilot, had a busman’s holiday when he ended up flying a plane that was delayed by two hours. He told passengers on board the Manchester Airport flight to Alicante that he was offering his services as there was no pilot available.The pilot said, “My wife is on row 15 with my little boy — hopefully he’s asleep by now. And I was told our flight’s delayed by two hours because there was no captain for the flight. So just before we went through security, I wondered if this is worth a phone call, I think it is because I’d like to go on holiday. I phoned up EasyJet and said ‘Hiya, I’m standing in the terminal doing nothing. I have got my licence with me and I’d very much like to go on holiday and if you need a favour, I’m standing here ready to go.’”Mr Bradley said his bosses called him back in less than a minute to give him the go-ahead, saying, “Please, please, can you fly the plane to Alicante?” He added, “So if you’re OK for one of your pilots to look like this without uniform today, we’ll go to Alicante.” There was cheers from the passengers.Ms Potts posted a video of the pilot’s announcement on Facebook, saying “The plane probably would have been cancelled if it wasn’t for him! Legend”.1 . How many families are there on the trip with Bradley?A 1.B 2.C 3.D 4.2 . Why did Michael Bradley make the call?A Because the flight would be cancelled.B Because he loved to serve people.C Because he wanted to be a legend.D Because he wanted to take a holiday.3 . What does the underlined word “go-ahead” mean in Chinese?A 接受.B 命令.C 准许.D 承诺.4 . How did the passengers feel about Michael Bradley’s act?A They loved it.B They ignored it.C They missed it.D They criticized it.5 . What is the main idea of this passage?A Spending a holiday with a pilot can make sure the flight never being cancelled.B Michael Bradley became a legend after becoming a pilot.C Michael Bradley had a bad holiday with his wife and son.D A passenger flied the plane to the destination when the captain couldn’t arrive.6一战创历史！加拿大19岁安德莱斯库勇夺2019美网大满贯中等记叙文文娱体育Andreescu, the 19-year-old Canadian girl won the 2019 US Open. She beat Serena Williams. Williams won her first US Open in 1999. Andreescu wasn’t even born then.Her rise has been quick. A year ago, she couldn’t even qualify for the US Open. But she always dreamt of winning it. When she was 16, she wrote herself a fake US Open winner’s cheque. The amount of the prize money rose in real life. She kept updating it on the cheque. On the night of her win, she really got the cheque! Before Andreescu, no player had won the US Open in their first appearance. It was also the first win by a Canadian.“Being able to play on this stage against Serena, a true legend in this sport, is amazing,” said Andreescu, who was appearing in her first major final, while Williams was in her 33rd. “Oh, man, it wasn’t easy at all.” Andreescu keeps dreaming big. “I’ve really tried to be like Serena. Who knows? Maybe I can be better,” she said.1 . When was Bianca Andreescu born?A In 1999.B In 2000.C In 2001.D In 2002.2 . What does the underlined word “qualify” mean?A 能战胜.B 能学习.C 有能力.D 有资格.3 . Which of the following statements is TRUE？A Andreescu won her first cheque at the age of 16.B Serena won her first US Open at the age of 19.C Andreescu is not the only Canadian winning the US Open.D Serena Williams is an excellent tennis player.4 . What can we learn from what Andreescu said?A Serena may become a better tennis player than Serena.B Serena is the best tennis player in the world.C Andreescu is another Serena.D Andreescu is a better tennis player than Serena.5 . What is the best title of this passage?A The first tennis US Open winner.B A rising tennis star Andreescu.C The 2019 US Open final.D The tennis legend Serena failed.7“飞的”时代来了！空中出租车在新加坡试飞成功最快2021年投入使用中等新闻报道科普知识Those dreams of having flying cars when we were younger may finally come true as flying taxis have made their debut on 22 October in Singapore and may be a permanent thing in 2 years.According to TODAY, an R&D version of the air taxi, the V olocopter 2X, flew for 3 minutes at noon around Marina Bay on 22 October. This debut is part of the Intelligent Transport Systems World Congress that is running from 21 to 25 October at Suntec Singapore Convention and Exhibition Centre. V olocopter’s spokesperson, Ms Helena Treeck, told TODAY that the company hopes to make flying taxis a thing in Singapore by 2021.The V olocopter is a 2-seater passenger drone that consists of 18 rotors. It can fly up to 30km in one charge. That’s roughly the distance between Jurong East & Punggol. The copter can go up to speeds of 110km/h. And since there are no obstacles or traffic lights in the air, it’s like taking a highway from pickup to destination. The flying taxi can fly unmanned because of an “intelligent operation system”.V olocopter has been engaging with the Transport Ministry, Civil Aviation Authority Of Singapore and the Economic Development Board to discuss the project of having air taxis in Singapore.1 . The passage introduces the first use of ________ in Singapore.A flying carsB flying taxisC flying enginesD flying motorbikes2 . The Volocopter 2X is _________ according to the passage.A a transport system used in SingaporeB a new type of transport in the air in SingaporeC a future model of going sightseeing in SingaporeD an industry robot made by a company in Singapore3 . What can we learn about the Volocopter 2X?A It can carry three passengers during a trip.B Its speed reaches up to 120 kilometres per hour.C It can keep flying along the highway with gas.D The farthest flight distance in one charge can reach 30 kilometres.4 . How long will it take you to go to school by Volocopter 2X if your home is about 11km away from your school?A 2 minutes.B 5 minutes.C 6 minutes.D 10 minutes.5 . What’s the main idea of this passage?A What the Volocopter 2X is.B The dreams of having flying cars have come true.C A flying car may be opened to public in Singapore in 2021.D The project of having air taxis has been discussed in Singapore.8印尼科莫多岛继续对游客开放较难记叙文旅游交通This spring, we reported on how Indonesia's government was planning to close Komodo Island in 2020. That report came out after several people were arrested in March and accused of smuggling Komodo dragons off the island. As many as 41 of the lizards were sold in other countries for $35,000 each.Now, the Indonesian government says it plans to keep Komodo Island open. However, it will put limits on the number of tourists.Last year, 180,000 people made that trip. We don't know what the new limit will be or how much it will cost to go there. But the Indonesian government is trying to balance calls for more wildlife protection with concerns that banning tourism will hurt the residents who depend on it for their income.Komodo dragons are considered a vulnerable species. It means that they could become endangered unless they're protected. There are more than 1,700 of these creatures on Komodo Island, and if you plan to go there, Komo — don't feed the wildlife. While they don't often attack people, the lizards are venomous and capable of killing someone. They can become as long as 10 feet and weigh 150 pounds.1 . Why did Indonesia's government plan to close Komodo Island in 2020?A There were too many tourists.B The weather was changeable on the island.C Several people smuggled Komodo dragons off the island.D The animals on the island were very famous.2 . What's the Chinese meaning of the underlined word “vulnerable” in Paragraph 4?A 易受伤害的.B 易狂躁的.C 具有攻击性的.D 温顺的.3 . How many people traveled to Komodo Island last year?A 35000.B 100000.C 150000.D 180000.4 . Which of the following is TRUE about Komodo dragons?A Komodo dragons are small animals and only eat grass.B Komodo dragons can become very huge.C Komodo dragons live in many countries around the world.D Komodo dragons can never be bad for people.5 . What's the main idea of this passage?A Indonesia is rich in animal resources.B An introduction of Komodo Island.C Reopening of Komodo Island to tourists.D The living habits of Komodo dragons.9国际足联：2021年世俱杯落户中国较难新闻报道文娱体育The expanded tournament will be held in the Far East in two years' time. China will host the newly-revised version of the FIFA Club World Cup in 2021, which is set to be played between the summer months of June and July.The revamped competition will now take place once every four years and is expected to feature eight teams from Europe. The current version of the tournament only includes seven teams, but FIFA's expansion will see that number rise to 24. The Club World Cup will now replace the Confederations Cup, which has served as a warm-up event for countries hosting the World Cup since 1992. FIFA has released an official statement w hich reads: “FIFA Council unanimously appoints China PR as hosts of new Club World Cup in 2021.”Speaking at a council meeting in Shanghai on Thursday, FIFA president Gianni Infantino stated: “This is a historic decision for football because the FIFA council decided unanimously to appoint China as the host for the new FIFA World Cup for clubs.” “The new FIFA World Cup for clubs will be a competition which every person who loves football looks forward to. It is the first real and true world cup for the best teams and clubs in the world.”1 . China was chosen to be the host of ________ in 2021.A the Asian CupB the World CupC the Club World CupD the Confederations Cup2 . How many football teams in the world will take part in the new competition in 2021?A 7.B 8.C 15.D 24.3 . What can we learn from the passage?A The expanded competition will be held every two years.B Summer is the most suitable season for football matches.C The World Cup is more powerful than the Confederations Cup.D More football teams from Europe will be invited to the football match.4 . The underlined words “a historic decision” in Paragraph 3 mean that _______.A the World Cup has been revisedB the FIFA members have expandedC the competition time has been increasedD China was appointed as the host of the Club World Cup。

极速击杀
“标准”-3系列导弹是“宙斯盾”系统的反弹道导弹，主要用于大气层外直接拦截处于上升段或中段的来袭弹道导弹，为海外美国海
部署在波兰的陆基“宙斯盾”
系统将在2018年左右完成，其使
用的拦截弹将采用性能更加强大
的“标准”-3 Block IIA型导弹，届
目前的主力
“标准”-3 Block I系列导弹
“标准”-3型导弹家族包括
“标准”-3 Block 0基本型、“标
—陆基“宙斯盾”的两种“标准”-3导弹
林颖清. All Rights Reserved.
“标准”-3 Block I型系列导弹采用的LEAP动能战斗部
“标准”-3 Block IA导弹发射瞬间. All Rights Reserved.
· 单色导引头· 脉冲式姿轨 控系统· 双色导引头
· 推力可调的姿轨控
系统
· 先进的全反射光学
系统
· 先进的信号处理器
· Block IB的导
引头
· 直径为534mm的
第二级和第三级
火箭发动机
· 直径为534mm的
头罩
· 适用于MK-41垂
直发射装置
· 更大直径的动能
战斗部
· 直径为534mm的
第二级和第三级
火箭发动机
· 直径为534mm的
头罩
· 适用于MK-41垂
直发射装置
扫描二维码，观看视频《美国用
准”-3导弹击毁卫星》
2014.08军事文摘。

UNIT4 SPACE EXPLORATION Section A Listening and Speaking课后篇巩固提升基础夯实Ⅰ.单句填空1.How many hours of (fly) experience does one need to become an astronaut?2.Yang Liwei is one of the most famous (astronaut) in the world.3.It has been proved that mental health is related physical health.4.My writing style is similar that of my brother’s.5.Do you know who is the first woman astronaut (go) into space?6.Her (intelligent) is comparatively favourable with that of his sister.7.In my opinion,climbing up to the top of the mountain is too difficult her.8.One of good properties of this metal is light weight.Ⅱ.短语填空(注意动词的适当形式)1.If you don’t pass in your subsidiary subject you can’t .2. we should make primary education universal.3.That is a problem that we middle school students must .4.In high school,I the computer,and built my first website.5.When I college,I made up my mind to make a journey to Tibet.6.18,Li Ming was sent to the US for further study.Ⅲ.完成句子1.对我来说这道数学题不容易计算出来。

第20卷第2期2022年2月太赫兹科学与电子信息学报Journal of Terahertz Science and Electronic Information TechnologyVol.20，No.2Feb.，2022关于Huynen目标参数与目标最佳极化关系的讨论徐志明，艾小锋*，李永祯，赵锋(国防科技大学电子科学学院CEMEE国家重点实验室，湖南长沙410073)摘要：Huynen目标参数和最佳极化(OPs)是极化信息处理中两个基本概念。

最佳极化在Poincare球上的分布根据Huynen目标参数的特征角可以细分为“针型”、“帽型”和“叉型”三种形态，目前尚缺乏完善的讨论。

本文基于Kennaugh矩阵推导了目标的最佳极化，讨论了Huynen目标参数与最佳极化的对应关系。

然后，基于三种最佳极化的分布形态讨论了几种典型结构目标的极化特性，可以为雷达极化学研究人员建立更清楚的概念。

关键词：Huynen目标参数；最佳极化；极化散射特性；极化叉中图分类号：TN95文献标志码：A doi：10.11805/TKYDA2020684 discussionOn about the relationship between Huynen targetparameters and optimum polarizationsXU Zhiming，AI Xiaofeng*，LI Yongzhen，ZHAO Feng(State Key Laboratory of Complex Electromagnetic Environmental Effects on Electronics and Information System，NationalUniversity of Defense Technology，Changsha Hunan410073，China)AbstractAbstract：：Huynen Target Parameters(HTPs)and Optimum Polarizations(OPs)are two fundamental concepts in the polarization information processing field.According to the characteristic angle of HTPs,the graphical representation of OPs can be divided into three classes,needle shape,top shape,and thewell-known fork shape,which has not been sufficiently discussed before.In this paper,OPs are derivedbased on the Kennaugh matrix.Then,the relationship between HTPs and OPs is revealed.On the basisof that,the polarization scattering characteristics of several typical structures are investigated.Thispaper aims to establish a clear concept about HTPs and OPs for radar polarimetry researchers.KeywordsKeywords：：Huynen target parameters；optimum polarizations；polarization scattering characteristics；polarization forkJ.R.Huynen在博士论文中最早分析了可以反映目标极化能力、奇/偶次散射、旋向和对称性几个物理特征的特征角γ、弹跳角v、定向角θ和对称角τ[1]。