The gauge boson contributions to the radiatively corrected mass of the scalar Higgs boson i

合集下载

GMAT-OG12-SC正确句子总结

1.The Glass House Mountains in Queensland, Australia, were sighted in 1770 by the Englishnavigator Captain James Cook, who so named them supposedly because their sheer wet rocks glistened like glass.2.Although a surge in retail sales has raised hopes that a recovery is finally under way, manyeconomists say that without a large amount of spending the recovery might not last.3.Although various eighteenth- and nineteenth-century American poets had professed an interestin Native American poetry and had pretended to imitate Native American forms in their own works, it was not until almost 1900 that scholars and critics seriously began studying traditional Native American poetry in native languages.4.Of all the vast tides of imgration that have swept through history, perhaps none was moreconcentrated than the wave that brought 12 million immigrants onto American shores in little more than three decades.5.Diabetes, together with its serious complications, ranks as the nation’s third leading cause ofdeath, surpassed only by heart disease and cancer.6.In late 1997, the chambers inside the pyramid of the Pharaoh Menkaure at Giza were closed tovistors for cleaning and repair because moisture exhaled by tourists had raised the humidity within them to such level that salt from the stone was crystallizing and fungus was growing on the walls,7.As its sales of computer products have surpassed those of measuring instruments, thecompany has become increasingly willing to compete for the mass market sales it would in the past have conceded to rivals.8.The widely accepted big bang theory holds that the universe began in an explosive instant tento twenty billion years ago and has been expanding ever since9.Like the Brontes and Brownings, James Joyce and Virginia Woolf are often subjected to thekind of veneration that blurs the distinction between the artist and the human being.10.Carnivorous mammals can endure what would otherwise be lethal level of body heat becausethey have a heat-exchange network that keeps the brain from getting too hot.11.There are several ways to build solid walls using just mud or clay, but the most extensivelyused method has been to form the mud or clay into bricks, and, after some preliminary air drying or sun drying, to lay them in the wall in mud mortar.12.Rising inventories, if not accompanied by corresponding increases in sales, can lead toproduction cutbacks that would hamper economic growth.13.A surge in new home sales and a drop in weekly unemployment claims suggest that theeconomy might not be as weak as some analysts previously thought.14.Sunspots,vortices of gas associated with strong electromagnetic activity, are visible as darkspots on the surface of the Sun but have never been sighted on the Sun's poles or equator. 15.Warning that computers in the United States are not secure, the National Academy of Scienceshas urged the nation to revamp computer security procedures, institute new emergency response teams, and create a special nongovernment organization to take charge of computer security planning.16.Retail sales rose 0.8 of 1 percent in August,intendifying expectations that personal spending inthe July-September quarter would more than double the 1.4 percent growth rate in personal spending for the previous quarter.17.The commission has directed advertisers to restrict the use of the word"natural"to foods thatdo not contain color of flavor additives, chemical preservatives, or anything that has been synthesized.18.Plants are more efficient than fungi at acquiring carbon, in the form of carbon dioxide, andconverting it to energy-rich sugars.19.The Iroquois were primarily planters, although they supplemented their cultivation of maize,squash, and beans with fishing and hunting20.Unlike the honeybee, the yellow jacket can sting repeatedly without dying and carries a potentvenom that can cause intense pain.21.Neuroscientist, having amassed a wealth of knowledge over the past twenty years about thebrain and its development from birth to adulthood, are now drawing solid conclusions about how the human brain grows and how babies acquire language.22.None of the attempts to specify the cause of crime explains why most of the people exposedto the alleged causes do not commit crimes and, conversely, why so many of those not so exposed do.23.Once designed with its weight concentrated in a metal center, the discus used in trackcompetition is now lined with lead around the perimeter, thereby improving stability in flight and resulting in longer throws.24.In virtually all types of tissue in every animal species, dioxin induces the production ofenzymes that are the organism's attempt to metabolize, or render harmless, the chemical irritant.ing accounts of various ancient writers, scholars have painted a sketchy picture of theactivities of an all-female cult that, perhaps as early as the sixth century B.C., worshipped a goddess known in Latin as Bona Dea,"the good goddess".26.Emily Dickinson's letters to Susan Huntington Dickinson, which were written over a periodbeginning a few years before Susan's marriage to Emily's brother and ending shortly before Emily's death in 1886, outnumber her letters to anyone else.27.Paleontologists believe that fragments of a primate jawbone unearthed in Burma andestimated to be 40 to 44 million years old provide evidence of a crucial step along the evolutionary path that led to human beings.28.Building on civilizations that preceded them in coastal Peru, the Mochica developed their ownelaborate society, based on the cultivation of such crops as corn and beans, the harvesting of fish and seafood, and the exploitation of other wild and domestic resources.29.The end of the eighteenth century saw the emergence of prize-stock breeding, with individualbulls and cows receiving awards, fetching unprecedented prices, and exciting enormous interest whenever they were put on show.30.For members of the seventeenth-century Ashanti nation in Africa, animal-hide shields withwooden frames were essential items of military equipment, protecting warriors against enemy arrows and spears.31.Even though many of her colleagues were convinced that genes were relatively simple andstatic, Brabara McClintock adhered to her own more complicated ideas about how genes might operate, and in 1983, at the age of 81, was awarded a Nobel Prize for her discovery that the genes in corn are capable of moving from one chromosomal site to another.32.Galileo was convinced that natural phenomena, as manifestations of the laws of physics,would appear the same to someone on the deck of a ship moving smoothly and uniformly through the water as to a person standing on land.33.Because an oversupply of computer chips has sent price plunging, the manufacturer hasannounced that it will cut production by closing its factories for two days a month.34.Beyond the immediate cash flaw crisis that the museum faces, its survival depends on whetherit can broaden its membership and leave its cramped quarters for a site where it can store and exhibit its more than 12,000 artifacts.35.Along with the drop in producer prices announced yesterday, the strong retail sales figuresreleased today seem to indicate that the economy, although growing slowly, is not nearing a recession.36.Dressed as a man and using the name Robert Shurtleff, Deborah Sampson, the first woman todraw a soldier's pension, joined the Continental Army in 1782 at the age of 22, was injured three times, and was discharged in 1783 because she had become too ill to serve.37.Although schistosomiasis is not often fatal, it is so debilitating that it has become an economicdrain on many developing countries.38.In 1850, Lucretia Mott published her Discourse on Women, a treatise that argued for equalpolitical and legal rights for women and for changes in the married women's property laws. 39.In 1527 King Henry VIII sought to have his marriage to Queen Catherine annulled so that hecould marry Anne Boleyn.40.Dr.Tonegawa won the Nobel Prize for discovering how the body can constantly change itsgenes to fashion a seemingly unlimited number of antibodies, each targeted specifically at an invading microbe or foreign substance.41.To develop more accurate population forecasts, demographers would have to know a greatdeal more than they do now about the social and economic determinants of fertility.42.Scientists have recently discovered what could be the largest and oldest living organism onEarth, a giant fungus that is an interwoven filigree of mushrooms and rootlike tentacles spawned by a single fertilized spore some 10,000 years ago and extending for more than 30 acres in the soil of a Michigan forest.os has a land area comparable to that of Great Britain but a population of only four millionpeople, many of whom are members of hill tribes ensconced in the virtually inaccessible mountain valleys of the north.44.The plot of the Bostonians centers on the rivalry that develops between Olive Chancellor, anactive feminist, and Basil Ransom,her charming and cynical cousin, when they find themselves drawn to the same radiant young woman whose talent for public speaking has won her an ardent following.45.Quasars, at billions of light-years from Earth the most distant observable objects in theuniverse, are believed to be the cores of galaxies in an early stage of development.46.In ancient Thailand, much of the local artisans' creative energy was expended on the creationof Buddha images and on construction and decoration of the temples in which they were enshrined.47.Five fledgling sea eagles left their nests in western Scotland this summer, bringing to 34 thenumber of wild birds successfully raised since transplants from Norway began in 1975.48.In 1713, Alexander Pope began his translation of the Iliad, a work that took him seven yearsuntil complete and that literary critic Samuel Johnson,Pope's contemporary, pronounced the greatest translation in any language.49.The automotive conveyor-belt system, which Henry Ford modeled after an assembly-linetechnique introduced by Ransom Olds, reduced the time required to assemble a Model T froma day and a half to 93 minutes.50.According to some analysts, the gains in the stock market reflect growing confidence that theeconomy will avoid the recession that many had feared earlier in the year and instead come in for a "soft landing", followed by a gradual increase in business activity.51.A new study suggests that the conversational pace of everyday life may be so brisk that ithampers the ability of some children to distinguish discrete sounds and words and, as a result, to make sense of speech.52.Long before it was fashionable to be an expatriate, Josephine Baker made Paris her home, andshe remained in France during the Second World War as a performer and an intelligence agent for the Resistance.53.The nineteenth-century chemist Humphry Davy presented the results of his early experimentsin his "Essay on Heat and Light," a critique of all chemistry since Robert Boyle as well as a vision of a new chemistry that Davy hoped to found.54.The report recommended that the hospital eliminate unneeded beds, consolidate expensiveservices, and use space in other hospitals.55.Many house builder offer rent-to-buy programs that enable a family with insufficient savingsfor a conventional down payment to move into new housing and to apply part of the rent to a purchase later.56.Many of the earliest known images of Hindu deities in India date from the time of the KushanEmpire and were fashioned either from the spotted sandstone of Mathura or from Gandharan grey schist57.It can hardly be said that educators are at fault for not anticipating the impact ofmicrocomputer technology: Alvin Toffler, one of the most prominent student of the future,did not even mention microcomputers in Future Shock, published in 1970.58.A leading figure in the Scottish Enlightenmen, Adam Smith wrote two major books that are todemocratic capitalism what Marx's Das Kapital is to socialism.59.The Olympic Games helped to keep peace among the pugnacious states of the Greek world，for a sacred truce was proclaimed during the month of festival.60.While all states face similar industrial waste problems, the predominating industries and theregulatory environment of each states obviously determine the types and amounts of waste produced, as well as the cost of disposal.61.Rivaling the pyramids of Egypt or even the ancient cities of the Maya as an achievement, thearmy of terra-cotta warriors created to protect Qin Shi Huang, China's first emperor, in his afterlife is more than 2,000 years old and took 700,000 artisans more than 36 years to complete.62.When Congress reconvenes, some newly elected members from rural states will try toestablish tighter restrictions on the amount of grain farmers will be allowed to grow and to encourage more aggressive sales of United States farm products overseas.63.The yield of natural gas from Norway's Troll gas field is expected to increase annually untilthe year 2005 and then to stabilize at six billion cubic feet a day, an extraction rate that will allow at least 50 years production.64.Doctors generally agree that such factors as cigarette smoking, eating rich foods high in fats,and alcohol consumption not only do damage by themselves but also aggravate genetic predispositions toward certain diseases.65.In a plan to stop the erosion of East Coast beaches, the Army Crops of Engineers proposedbuilding parallel to shore a breakwater of rocks that would rise six feet above the waterline and act as a buffer, absorbing the energy of crashing waves and pretecting the beaches.66.The 32 species that make up the dolphin family are closely related to whales and in factinclude the animal known as the killer whale, which can grow to be 30 feet long and is famous for its aggressive hunting pods.67.Affording strategic proximity to the Strait Gibraltar,Morocco was also of interest to theFrench throughout the first half of the twentieth century because they assumed that without it their trip on Algeria would never be secure.68.The first trenches cut into a 500-acre site at Tell Hamoukar,Syria, have yielded strongevidence that centrally administered complex societies in northern regions of the Middle East arose simultaneously with but independently of the more celebrated city-states of southern Mesopotamia, in what is now southern Iraq.69.Once they had seen the report from the medical examiner, the investigators had no doubt thatthe body recovered from the river was that of the man who had attempted to escape from the state prison.70.His studies of ice-polished rocks in his Alpine homeland, far outside the range of present-dayglaciers, led Louis Agassiz in 1837 to propose the concept of an age in which great ice sheets existed in what are now temperate areas.71.Unlike the original National Museum of Science and Technology in Italy, where the modelsare encased in glass or operated only by staff members, the Virtual Leonardo Project,an online version of the museum,encourages visitors to "touch" each exhibit and thereby (to) activate the animated functions of the piece72.More and more in recent years,cities are stressing the arts as a means to greater economicdevelopment and investing millions of dollars in cultural activities, despite strained municipal budgets and fading federal support.bining enormous physical strength with higher intelligence, the Neanderthals appear tohave been equipped to face any obstacle the environment could put in their path, but their relatively sudden disappearance during the Paleolithic era indicates that an inability to adapt to some environmental change led to their extinction.74.A 1972 agreement between Canada and the United States reduced the amount of phosphatesthat municipalities are allowed to dump into the Great Lakes75.A proposal has been made to trim the horns from rhinoceroses to discourage poachers；thequestion is whether tourists will continue to visit game parks to see rhinoceroses once the animals' horns have been trimmed.76.Retailers reported moderate gains in their November sales, as much because their sales a yearearlier had been so bad as because shoppers were getting a head start on buying their holiday gifts.77.The only way for growers to salvage frozen citrus is to have it quickly processed into juiceconcentrate before warmer weather returns and rots the fruit.78.Fossils of the arm of a sloth, found in Puerto Rico in 1991, have been dated at 34 millionyears old, making the sloth the earliest known mammal on the Greater Antilles Islands.79.Defense attorneys have occasionally argued that their client's misconduct stemmed from areaction to something ingested, but if criminal or delinquent behavior is attributed to an allergy to some food, the perpetrators are in effect told that they are not responsible for their action.80.A report by the American Academy for the Advancement of Science has concluded that manyof the currently uncontrolled dioxins to which North Americans are exposed come from the incineration of wastes.81.Recently physicians have determined that stomach ulcers are caused not by stress, alcohol, orrich foods, but by a bacterium that dwells in the mucous lining of the stomach.82.According to a recent poll, owning and living in a freestanding house on its own land is still agoal of a majority of young adults, as it was of earlier generations.83.In 2000, a mere two dozen products accounted for half the increase in spending onprescription drugs, a phenomenon that is explained not just by the fact that drugs are becoming more expensive but also by the fact that doctors are writing many more prescriptions for higher-cost drugs.84.Often visible as smog, ozone is formed in the atmosphere when hydrocarbons and nitrogenoxides, two major pollutants emitted by automobiles, react with sunlight.85.Salt deposits and moisture threaten to destory the Mohenjo-Daro excavation in Pakistan, thesite of an ancient civilization that flourished at the same time as the civilizations in the Nile Delta and the river valleys of the Tigris and Euphrates.86.The results of the company's cost-cutting measures are evident in its profits, which haveincreased 5 percent during the first 3 months of this year after falling over the last two years.87.In an effort to reduce their inventories, Italian vintners have cut prices; their wines are pricedto sell, and they do.88.Jazz pianist and composer Thelonious Monk produced a body of work that was rooted in thestride-piano tradition of Willie(The Lion) Smith and Duke Elligton, yet in many ways he stood apart from the mainstream jazz repertory.89.Dirt roads may evoke the bucolic simplicity of another century, but financially strainedtownships point out that dirt roads cost twice as much to maintain as paved roads do.90.Although early soap operas were first aired on evening radio in the 1920s, they were moved tothe daytime hours in the 1930s when the evening schedule became crowded with comedians and variety shows.91.Nobody knows exactly how many languages there are in the world, partly because of thedifficulty of distinguishing between a language and the sublanguages or dialects within it, but those who have tried to count typically have found about five thousand.92.The energy source on V oyager 2 is not a unclear reactor, in which atoms are activity brokenapart, but rather a kind of unclear battery that uses natural radioactive decay to produce power.93.Heating-oil prices are expected to be higher this year than last because refiners are payingabout $5 a barrel more for crude oil than they were last year.94.The recent surge in the number of airplane flights has clogged the nation's air-traffic controlsystem, leading to a 55 percent increase in delays at airports and prompting fear among some officials that safety is being compromised.95.The peaks of a mountain range,acting like rocks in a streambed, produce ripples in the airflowing over them；the resulting flow pattern, with crests and troughs that remain stationary although the air that forms them is moving rapidly, is known as "standing waves".96.One of the primary distinctions between our intelligence and that of other primates may lienot so much in any specific skill as in our ability to extend knowledge gained in one context to new and different ones.97.Unlike Schoenberg, whose 12-tone system dominated the music of the postwar period, Bartokfounded no school and left behind only a handful of disciples.98.Even though Clovis points, spear points with longitudinal grooves chipped onto their faces,have been found all over North America, they are named for the New Mexico site where they were first discovered in 1932.99.Ranked as one of the most important of Europe's young playwrights, Franz Xaver Kroetz haswritten 40 plays；his works-translated into the more than 30 language-are produced more often than those of any other contemporary German dramatist.100.Like the planets, the stars are in motion,some of them at tremendous speeds, but they are so far away from earth that their apparent positions in the sky do not change enough for their movement to be observed during a single human lifetime.101.Being heavily committed to a course of action, especially one that has worked well in the past, is likely to make an executive miss signs of incipient trouble or misinterpret them when they do appear.102.As rainfall began to decrease in the Southwest about the middle of the twelfth century, most of the Monument Valley Anasazi abandoned their homes to join other clans whose access to water was less limited.103.Yellow jackets number among the 900 or so species of the world's social wasps, wasps that live in a highly cooperative and organized society consisting almost entirely of females--the queen and her sterile female workers.104.El Nino, the periodic abnormal warming of the sea surface off Peru, is a phenomenon in which changes in the ocean and atmosphere combine to allow the warm water that has accumulated in the western Pacific to flow back to the east.105.In her book illustrations,which she carefully coordinated with her narratives, Beatrix Potter capitalized on her keen observation and love of the natural world.106.Marconi conceived of the radio as a tool for private conversation that could substitute for the telephone；instead, it has become precisely the opposite, a tool for communicating with a large, public audience.107.Originally developed for detecting air pollutants, a technique called proton-indeced X-ray emission, which can quickly analyze the chemical elements in almost any substance without destroying it, is finding uses in medicine, archaeology, and criminology.108.Authoritative parents are more likely than permissive parents to have children who as adolescents are self-confident, high in self-esteem, and responsibly independent.109.Among the objects found in the excavated temple were small terra-cotta effigies left by supplicants who were either asking the goddess Bona Dea's aid in healing physical and mental ills or thanking her for such help.110.Published in Harlem, The Messenger was owned and edited by two young journalists, A.Philip Randolph, who would later make his reputation as a labor leader, and Chandler Owen. 111.Construction of the Roman Colosseum, which was officially known as the Flavian Amphitheater, began in A.D.69, during the reign of Vespasian, and was completed the Colosseum with a one-hundred-day cycle of religious pageants, gladitorial games, and spectacles.112.A baby emerges from the darkness of the womb with a rudimentary sense of vision that would be rated about 20/500; an adult with such vision would be deemed legally blind. 113.Because the new maritime code provides that even tiny islets can be the basis for claim to the fisheries and oil fileds of large sea areas, it has already stimulated international disputes over uninhabited islands.114.The original building and loan associations were organized as limited life funds, whose members made monthly payments on their share subscriptions and then took turns drawing on the funds for home mortgages.115.Gill's hypothesis that different mental functions are localized in diferent parts of the brain is widely accepted today.116.Mauritius was a British colony for almost 200 years, but expect in the domains of administration and teaching, the English language was never really spoken on the island. 117.George Sand(Aurore Lucile Dupin)was one of the first European writers to consider the rural poor legitimate subjects for literature and to portray them with sympathy and respect in her novels.118.The World Wildlife Fund has declared that global warming, a phenomenon that most scientists agree is caused by human beings' burning of fossil fules, will create havoc among migratory birds by altering the environment in ways harmful to their habitats.119.New theories propose that catastrophic impacts of asteroids and comets may have caused reversals in the Earth's magnetic field, the onset of ice ages, the splitting apart of continents 80 million years ago, and great volcanic eruptions.120.A firm that specializes in the analysis of handwriting claims to be able, from a one-page writing sample, to assess more than 300 personality traits, including enthusiasm, imagination, and ambition.121.Sales of wines declined in the late 1980s, but they began to grow again after the 1991 report that linked moderate consumption of alcohol, and particularly of red wine, with a reduced risk of heart disease.122.A wildlife expert predicts that the reintroduction of the caribou into northern Minnesota will fail if the density of the timber wolf population in that region is greater than one wolf for every 39 square miles.123.Less successful after she emigrated to New York than she had been in her native Germany, photographer Lotte Jacobi nevertheless earned a small group of discerning admires, and her photographs were eventually exhibited in prestigious galleries across the United States.124.Found throughout Central and South America, the sloth hangs from trees by its long rubbery limbs, sleeping 15 hours a day and moving so infrequently that two species of algae grow on its coat and between its toes.125.Today, because of improvements in agricultural technology, the same amount of acreage produces twice as many apples as it did in 1910.126.The use of lie detectors is based on the assumption that lying produces emotional reactions in an anduvidual that, in turn, create unconscious physiological responses.127.Joan of Arc, a young Frenchwoman who claimed to be divinely inspired, turned the tide of English victories in her country by liberating the city of Orleans and persuaded Charles VII of French to claim his throne.128.Australian embryologists have found evidence to suggest that the elephant is descended from an aquatic animal and that its trunk originally evolved as a kind of snorkel.129.Cajuns speak a dialect brought to southern Louisiana by the 4,000 Acadians who migrated there in 1755; their language is basically seventeenth-century French to which English, Spanish, and Italian words have been added.130.One view of the economy contends that a large drop in oil prices should eventually lead to a lowering of interest rates and of fears about inflation, a rally in stocks and bonds, and a weakening of the dollar.131.Over 75 percent of the energy produced in France derives from unclear power, whereas unclear power accounts for just over 33 percent of the energy produced in Germany.132.Although the term "psychopath"is popularly applied to an especially brutal criminal, in psychology it refers to someone who is apparently incapable of feeling compassion or the pangs of conscience.st week local shrimpers held a news conference to take some credit for the resurgence of the rate Kemp's ridley turtle, saying that their compliance with laws requiring turtle-excluder devices on shrimp nets is protecting adult sea turtles.134.Recently implemented "shift-work equatios" based on studies of the human sleep cycle have reduced sickness, sleeping on the job, and fatigue among shift workers while raising production efficiency in various industries.135.Spanning more than 50 years, Friedrich Muller's career began in an unpromising apprenticeship as a Sanskrit scholar and culminated in virtually every honor that European governments and learned societies could bestow.136.Whereas in mammals the tiny tubes that convey nutrients to bone cells are arrayed in parallel lines, in birds the tubes form a random pattern.137.Joachim Raff and Giacomo Meyerbeer are examples of the kind of composer who receives popular acclaim while living, but whose reputation declines after death and never regains its former status.138.In no other historical sighting did Halley's Comet cause such a worldwide sensation as in its return of 1910-1911.139.The company announced that its profits declined much less in the second quarter than analysts had expected and that its business would improve in the second half of the year. 140.Rock samples taken from the remains of an asteroid about twice the size of the 6-mile-wide asteroid that eradicated the dinosaurs have been dated at 3.47 billion years old and thus are evidence of the earliest known asteroid impact on Earth.。

PACSnumbers1215Ff,1130Hv,1210Dm,1125Mj…

a r X i v :0803.2889v 2 [h e p -p h ] 14 J u l 2008Mapping Out SU (5)GUTs with Non-Abelian Discrete Flavor SymmetriesFlorian Plentinger ∗and Gerhart Seidl †Institut f¨u r Physik und Astrophysik,Universit¨a t W¨u rzburg,Am Hubland,D 97074W¨u rzburg,Germany(Dated:December 25,2013)We construct a class of supersymmetric SU (5)GUT models that produce nearly tribimaximal lepton mixing,the observed quark mixing matrix,and the quark and lepton masses,from discrete non-Abelian ﬂavor symmetries.The SU (5)GUTs are formulated on ﬁve-dimensional throats in the ﬂat limit and the neutrino masses become small due to the type-I seesaw mechanism.The discrete non-Abelian ﬂavor symmetries are given by semi-direct products of cyclic groups that are broken at the infrared branes at the tip of the throats.As a result,we obtain SU (5)GUTs that provide a combined description of non-Abelian ﬂavor symmetries and quark-lepton complementarity.PACS numbers:12.15.Ff,11.30.Hv,12.10.Dm,One possibility to explore the physics of grand uniﬁed theories (GUTs)[1,2]at low energies is to analyze the neutrino sector.This is due to the explanation of small neutrino masses via the seesaw mechanism [3,4],which is naturally incorporated in GUTs.In fact,from the perspective of quark-lepton uniﬁcation,it is interesting to study in GUTs the drastic diﬀerences between the masses and mixings of quarks and leptons as revealed by current neutrino oscillation data.In recent years,there have been many attempts to re-produce a tribimaximal mixing form [5]for the leptonic Pontecorvo-Maki-Nakagawa-Sakata (PMNS)[6]mixing matrix U PMNS using non-Abelian discrete ﬂavor symme-tries such as the tetrahedral [7]and double (or binary)tetrahedral [8]groupA 4≃Z 3⋉(Z 2×Z 2)and T ′≃Z 2⋉Q,(1)where Q is the quaternion group of order eight,or [9]∆(27)≃Z 3⋉(Z 3×Z 3),(2)which is a subgroup of SU (3)(for reviews see, e.g.,Ref.[10]).Existing models,however,have generally dif-ﬁculties to predict also the observed fermion mass hierar-chies as well as the Cabibbo-Kobayashi-Maskawa (CKM)quark mixing matrix V CKM [11],which applies especially to GUTs (for very recent examples,see Ref.[12]).An-other approach,on the other hand,is oﬀered by the idea of quark-lepton complementarity (QLC),where the so-lar neutrino angle is a combination of maximal mixing and the Cabibbo angle θC [13].Subsequently,this has,in an interpretation of QLC [14,15],led to a machine-aided survey of several thousand lepton ﬂavor models for nearly tribimaximal lepton mixing [16].Here,we investigate the embedding of the models found in Ref.[16]into ﬁve-dimensional (5D)supersym-metric (SUSY)SU (5)GUTs.The hierarchical pattern of quark and lepton masses,V CKM ,and nearly tribi-maximal lepton mixing,arise from the local breaking of non-Abelian discrete ﬂavor symmetries in the extra-dimensional geometry.This has the advantage that theFIG.1:SUSY SU (5)GUT on two 5D intervals or throats.The zero modes of the matter ﬁelds 10i ,5H,24H ,and the gauge supermul-tiplet,propagate freely in the two throats.scalar sector of these models is extremely simple without the need for a vacuum alignment mechanism,while of-fering an intuitive geometrical interpretation of the non-Abelian ﬂavor symmetries.As a consequence,we obtain,for the ﬁrst time,a realization of non-Abelian ﬂavor sym-metries and QLC in SU (5)GUTs.We will describe our models by considering a speciﬁc minimal realization as an example.The main features of this example model,however,should be viewed as generic and representative for a large class of possible realiza-tions.Our model is given by a SUSY SU (5)GUT in 5D ﬂat space,which is deﬁned on two 5D intervals that have been glued together at a common endpoint.The geom-etry and the location of the 5D hypermultiplets in the model is depicted in FIG.1.The two intervals consti-tute a simple example for a two-throat setup in the ﬂat limit (see,e.g.,Refs.[17,18]),where the two 5D inter-vals,or throats,have the lengths πR 1and πR 2,and the coordinates y 1∈[0,πR 1]and y 2∈[0,πR 2].The point at y 1=y 2=0is called ultraviolet (UV)brane,whereas the two endpoints at y 1=πR 1and y 2=πR 2will be referred to as infrared (IR)branes.The throats are supposed to be GUT-scale sized,i.e.1/R 1,2 M GUT ≃1016GeV,and the SU (5)gauge supermultiplet and the Higgs hy-permultiplets 5H and2neously broken to G SM by a 24H bulk Higgs hypermulti-plet propagating in the two throats that acquires a vac-uum expectation value pointing in the hypercharge direc-tion 24H ∝diag(−12,13,15i ,where i =1,2,3is the generation index.Toobtainsmall neutrino masses via the type-I seesaw mechanism [3],we introduce three right-handed SU (5)singlet neutrino superﬁelds 1i .The 5D Lagrangian for the Yukawa couplings of the zero mode fermions then readsL 5D =d 2θ δ(y 1−πR 1) ˜Y uij,R 110i 10j 5H +˜Y d ij,R 110i 5H +˜Y νij,R 15j5i 1j 5H +M R ˜Y R ij,R 21i 1j+h.c. ,(3)where ˜Y x ij,R 1and ˜Y x ij,R 2(x =u,d,ν,R )are Yukawa cou-pling matrices (with mass dimension −1/2)and M R ≃1014GeV is the B −L breaking scale.In the four-dimensional (4D)low energy eﬀective theory,L 5D gives rise to the 4D Yukawa couplingsL 4D =d 2θ Y u ij 10i 10j 5H +Y dij10i 5H +Y νij5i ∼(q i 1,q i 2,...,q i m ),(5)1i ∼(r i 1,r i 2,...,r im ),where the j th entry in each row vector denotes the Z n jcharge of the representation.In the 5D theory,we sup-pose that the group G A is spontaneously broken by singly charged ﬂavon ﬁelds located at the IR branes.The Yukawa coupling matrices of quarks and leptons are then generated by the Froggatt-Nielsen mechanism [21].Applying a straightforward generalization of the ﬂavor group space scan in Ref.[16]to the SU (5)×G A represen-tations in Eq.(5),we ﬁnd a large number of about 4×102ﬂavor models that produce the hierarchies of quark and lepton masses and yield the CKM and PMNS mixing angles in perfect agreement with current data.A distri-bution of these models as a function of the group G A for increasing group order is shown in FIG.2.The selection criteria for the ﬂavor models are as follows:First,all models have to be consistent with the quark and charged3 lepton mass ratiosm u:m c:m t=ǫ6:ǫ4:1,m d:m s:m b=ǫ4:ǫ2:1,(6)m e:mµ:mτ=ǫ4:ǫ2:1,and a normal hierarchical neutrino mass spectrumm1:m2:m3=ǫ2:ǫ:1,(7)whereǫ≃θC≃0.2is of the order of the Cabibbo angle.Second,each model has to reproduce the CKM anglesV us∼ǫ,V cb∼ǫ2,V ub∼ǫ3,(8)as well as nearly tribimaximal lepton mixing at3σCLwith an extremely small reactor angle 1◦.In perform-ing the group space scan,we have restricted ourselves togroups G A with orders roughly up to 102and FIG.2shows only groups admitting more than three valid mod-els.In FIG.2,we can observe the general trend thatwith increasing group order the number of valid modelsper group generally increases too.This rough observa-tion,however,is modiﬁed by a large“periodic”ﬂuctu-ation of the number of models,which possibly singlesout certain groups G A as particularly interesting.Thehighly populated groups would deserve further system-atic investigation,which is,however,beyond the scopeof this paper.From this large set of models,let us choose the groupG A=Z3×Z8×Z9and,in the notation of Eq.(5),thecharge assignment101∼(1,1,6),102∼(0,3,1),103∼(0,0,0),52∼(0,7,0),52↔4FIG.3:Eﬀect of the non-Abelian ﬂavor symmetry on θ23for a 10%variation of all Yukawa couplings.Shown is θ23as a function of ǫfor the ﬂavor group G A (left)and G A ⋉G B (right).The right plot illustrates the exact prediction of the zeroth order term π/4in the expansion θ23=π/4+ǫ/√2and the relation θ13≃ǫ2.The important point is that in the expression for θ23,the leading order term π/4is exactly predicted by thenon-Abelian ﬂavor symmetry G F =G A ⋉G B (see FIG.3),while θ13≃θ2C is extremely small due to a suppression by the square of the Cabibbo angle.We thus predict a devi-ation ∼ǫ/√2,which is the well-known QLC relation for the solar angle.There have been attempts in the literature to reproduce QLC in quark-lepton uniﬁed models [26],however,the model presented here is the ﬁrst realization of QLC in an SU (5)GUT.Although our analysis has been carried out for the CP conserving case,a simple numerical study shows that CP violating phases (cf.Ref.[27])relevant for neutri-noless double beta decay and leptogenesis can be easily included as well.Concerning proton decay,note that since SU (5)is bro-ken by a bulk Higgs ﬁeld,the broken gauge boson masses are ≃M GUT .Therefore,all fermion zero modes can be localized at the IR branes of the throats without intro-ducing rapid proton decay through d =6operators.To achieve doublet-triplet splitting and suppress d =5pro-ton decay,we may then,e.g.,resort to suitable extensions of the Higgs sector [28].Moreover,although the ﬂavor symmetry G F is global,quantum gravity eﬀects might require G F to be gauged [29].Anomalies can then be canceled by Chern-Simons terms in the 5D bulk.We emphasize that the above discussion is focussed on a speciﬁc minimal example realization of the model.Many SU (5)GUTs with non-Abelian ﬂavor symmetries,however,can be constructed along the same lines by varying the ﬂavor charge assignment,choosing diﬀerent groups G F ,or by modifying the throat geometry.A de-tailed analysis of these models and variations thereof will be presented in a future publication [30].To summarize,we have discussed the construction of 5D SUSY SU (5)GUTs that yield nearly tribimaximal lepton mixing,as well as the observed CKM mixing matrix,together with the hierarchy of quark and lepton masses.Small neutrino masses are generated only by the type-I seesaw mechanism.The fermion masses and mixings arise from the local breaking of non-Abelian ﬂavor symmetries at the IR branes of a ﬂat multi-throat geometry.For an example realization,we have shown that the non-Abelian ﬂavor symmetries can exactly predict the leading order term π/4in the sum rule for the atmospheric mixing angle,while strongly suppress-ing the reactor angle.This makes this class of models testable in future neutrino oscillation experiments.In addition,we arrive,for the ﬁrst time,at a combined description of QLC and non-Abelian ﬂavor symmetries in SU (5)GUTs.One main advantage of our setup with throats is that the necessary symmetry breaking can be realized with a very simple Higgs sector and that it can be applied to and generalized for a large class of uniﬁed models.We would like to thank T.Ohl for useful comments.The research of F.P.is supported by Research Train-ing Group 1147“Theoretical Astrophysics and Particle Physics ”of Deutsche Forschungsgemeinschaft.G.S.is supported by the Federal Ministry of Education and Re-search (BMBF)under contract number 05HT6WWA.∗********************************.de †**************************.de[1]H.Georgi and S.L.Glashow,Phys.Rev.Lett.32,438(1974);H.Georgi,in Proceedings of Coral Gables 1975,Theories and Experiments in High Energy Physics ,New York,1975.[2]J.C.Pati and A.Salam,Phys.Rev.D 10,275(1974)[Erratum-ibid.D 11,703(1975)].[3]P.Minkowski,Phys.Lett.B 67,421(1977);T.Yanagida,in Proceedings of the Workshop on the Uniﬁed Theory and Baryon Number in the Universe ,KEK,Tsukuba,1979;M.Gell-Mann,P.Ramond and R.Slansky,in Pro-ceedings of the Workshop on Supergravity ,Stony Brook,5New York,1979;S.L.Glashow,in Proceedings of the 1979Cargese Summer Institute on Quarks and Leptons, New York,1980.[4]M.Magg and C.Wetterich,Phys.Lett.B94,61(1980);R.N.Mohapatra and G.Senjanovi´c,Phys.Rev.Lett.44, 912(1980);Phys.Rev.D23,165(1981);J.Schechter and J.W. F.Valle,Phys.Rev.D22,2227(1980);zarides,Q.Shaﬁand C.Wetterich,Nucl.Phys.B181,287(1981).[5]P.F.Harrison,D.H.Perkins and W.G.Scott,Phys.Lett.B458,79(1999);P.F.Harrison,D.H.Perkins and W.G.Scott,Phys.Lett.B530,167(2002).[6]B.Pontecorvo,Sov.Phys.JETP6,429(1957);Z.Maki,M.Nakagawa and S.Sakata,Prog.Theor.Phys.28,870 (1962).[7]E.Ma and G.Rajasekaran,Phys.Rev.D64,113012(2001);K.S.Babu,E.Ma and J.W.F.Valle,Phys.Lett.B552,207(2003);M.Hirsch et al.,Phys.Rev.D 69,093006(2004).[8]P.H.Frampton and T.W.Kephart,Int.J.Mod.Phys.A10,4689(1995); A.Aranda, C. D.Carone and R.F.Lebed,Phys.Rev.D62,016009(2000);P.D.Carr and P.H.Frampton,arXiv:hep-ph/0701034;A.Aranda, Phys.Rev.D76,111301(2007).[9]I.de Medeiros Varzielas,S.F.King and G.G.Ross,Phys.Lett.B648,201(2007);C.Luhn,S.Nasri and P.Ramond,J.Math.Phys.48,073501(2007);Phys.Lett.B652,27(2007).[10]E.Ma,arXiv:0705.0327[hep-ph];G.Altarelli,arXiv:0705.0860[hep-ph].[11]N.Cabibbo,Phys.Rev.Lett.10,531(1963);M.Kobayashi and T.Maskawa,Prog.Theor.Phys.49, 652(1973).[12]M.-C.Chen and K.T.Mahanthappa,Phys.Lett.B652,34(2007);W.Grimus and H.Kuhbock,Phys.Rev.D77, 055008(2008);F.Bazzocchi et al.,arXiv:0802.1693[hep-ph];G.Altarelli,F.Feruglio and C.Hagedorn,J.High Energy Phys.0803,052(2008).[13]A.Y.Smirnov,arXiv:hep-ph/0402264;M.Raidal,Phys.Rev.Lett.93,161801(2004);H.Minakata andA.Y.Smirnov,Phys.Rev.D70,073009(2004).[14]F.Plentinger,G.Seidl and W.Winter,Nucl.Phys.B791,60(2008).[15]F.Plentinger,G.Seidl and W.Winter,Phys.Rev.D76,113003(2007).[16]F.Plentinger,G.Seidl and W.Winter,J.High EnergyPhys.0804,077(2008).[17]G.Cacciapaglia,C.Csaki,C.Grojean and J.Terning,Phys.Rev.D74,045019(2006).[18]K.Agashe,A.Falkowski,I.Low and G.Servant,J.HighEnergy Phys.0804,027(2008);C.D.Carone,J.Erlich and M.Sher,arXiv:0802.3702[hep-ph].[19]Y.Kawamura,Prog.Theor.Phys.105,999(2001);G.Altarelli and F.Feruglio,Phys.Lett.B511,257(2001);A.B.Kobakhidze,Phys.Lett.B514,131(2001);A.Hebecker and J.March-Russell,Nucl.Phys.B613,3(2001);L.J.Hall and Y.Nomura,Phys.Rev.D66, 075004(2002).[20]D.E.Kaplan and T.M.P.Tait,J.High Energy Phys.0111,051(2001).[21]C.D.Froggatt and H.B.Nielsen,Nucl.Phys.B147,277(1979).[22]Y.Nomura,Phys.Rev.D65,085036(2002).[23]H.Georgi and C.Jarlskog,Phys.Lett.B86,297(1979).[24]H.Arason et al.,Phys.Rev.Lett.67,2933(1991);H.Arason et al.,Phys.Rev.D47,232(1993).[25]D.S.Ayres et al.[NOνA Collaboration],arXiv:hep-ex/0503053;Y.Hayato et al.,Letter of Intent.[26]S.Antusch,S.F.King and R.N.Mohapatra,Phys.Lett.B618,150(2005).[27]W.Winter,Phys.Lett.B659,275(2008).[28]K.S.Babu and S.M.Barr,Phys.Rev.D48,5354(1993);K.Kurosawa,N.Maru and T.Yanagida,Phys.Lett.B 512,203(2001).[29]L.M.Krauss and F.Wilczek,Phys.Rev.Lett.62,1221(1989).[30]F.Plentinger and G.Seidl,in preparation.。

中国地质大学(北京)考博专业英复习材料

晶） is said to have a porphyritic texture（斑状结构）. The classification of fine-grained rocks, then, is based on the proportion of minerals which form phenocrysts and these phenocrysts （斑晶）reflect the general composition of the remainder(残留) of the rock. The fine-grained portion of a porphyritic（斑岩） rock is generally referred to as the groundmass（基质） of the phenocrysts. The terms "porphyritic" and "phenocrysts" are not restricted to fine-grained rocks but may also apply to coarse-grained rocks which contain a few crystals distinctly larger than the remainder. The term obsidian(黑曜岩) refers to a glassy rock of rhyolitic（流纹岩） composition. In general, fine-grained rocks consisting of small crystals cannot readily be distinguished from③ glassy rocks in which no crystalline material is present at all. The obsidians, however, are generally easily recognized by their black and highly glossy appearanceass of the same composition as obsidian. Apparently the difference between the modes of formation of obsidian and pumice is that in pumice the entrapped water vapors have been able to escape by a frothing（起泡） process which leaves a network of interconnected pore（气孔） spaces, thus giving the rock a highly porous （多孔的）and open appearance（外观较为松散）. ④ Pegmatite（结晶花岗岩） is a rock which is texturally（构造上地） the exact opposite of obsidian. ⑤ Pegmatites are generally formed as dikes associated with major bodies of granite （花岗岩） . They are characterized by extremely large individual crystals （单个晶体） ; in some pegmatites crystals up to several tens of feet in length（宽达几十英尺）have been identified, but the average size is measured in inches （英寸） . Most mineralogical museums contain a large number of spectacular（壮观的） crystals from pegmatites. Peridotite（橄榄岩） is a rock consisting primarily of olivine, though some varieties contain pyroxene（辉石） in addition. It occurs only as coarse-grained intrusives（侵入）, and no extrusive（喷出的） rocks of equivalent chemical composition have ever been found. Tuff （凝灰岩）is a rock which is igneous in one sense （在某种意义上） and sedimentary in another⑥. A tuff is a rock formed from pyroclastic （火成碎屑的）material which has been blown out of a volcano and accumulated on the ground as individual fragments called ash. Two terms（igneous and sedimentary） are useful to refer solely to the composition of igneous rocks regardless of their textures. The term silicic (硅质的)signifies an abundance of silica-rich（富硅） and light-colored minerals（浅色矿物）, such as quartz, potassium feldspar（钾长石）, and sodic plagioclase （钠长石） . The term basic （基性） signifies （意味着） an abundance of dark colored minerals relatively low in silica and high in calcium, iron, and

15-16(social issues)

Debating topic I: Should the driver open the door, or keep it closed?
Background: As the bus approached a bus station, a girl cried out: “My mobile phone has been stolen by somebody on the bus. Please do not open the door until the police come.” Some other passengers opposed :”I’ve got very urgent things to do. Open the door, let me get off.” Who should the driver listen to? Side A: 1) We should show sympathy to the girl since she is the victim. 2) The thief should not be spared. 3) It’s everyone’s duty to protect the good social order. … Side B: 1) The girl should think out a better way to solve the problem than to keep so many people wasting time because of her, since in this modern world time is money. 2) The over-majority’s opinions should be counted.. over3) The driver should listen to neither of the girl or the passenger but call the police and obey their orders. … Judge: It may be debatable whether the door should be open or remain shut. Yet one thing can never be over-emphasized: people should show more concern to each other. People should try overto stand in each other’s shoes and have a better understanding of each other’s position so that they unite to better combat thieves and other bad things in the society.

英语名著阅读试题及答案

英语名著阅读试题及答案一、选择题1. In which novel does the character Elizabeth Bennet appear?A. Pride and PrejudiceB. Great ExpectationsC. Jane EyreD. Wuthering Heights答案：A2. What is the main theme of "To Kill a Mockingbird" by Harper Lee?A. Love and romanceB. Social injusticeC. Adventure and explorationD. Science fiction答案：B3. In "1984" by George Orwell, what does the term "Big Brother" represent?A. A family memberB. A political leaderC. A surveillance systemD. A friendly neighbor答案：C二、填空题4. The protagonist of "The Great Gatsby" is _______, who is a mysterious millionaire.答案：Jay Gatsby5. In "Frankenstein," the creature created by Victor Frankenstein is often referred to as a _______.答案：monster6. "Moby Dick" by Herman Melville is a novel about the obsessive quest of Captain Ahab for a _______ whale.答案：white三、简答题7. What is the significance of the title "Pride and Prejudice" in relation to the novel's themes?答案：The title "Pride and Prejudice" reflects the central themes of the novel, which are the destructive nature of pride and the initial prejudices that characters hold against each other, which must be overcome for personal growth and understanding.8. How does Charles Dickens use social commentary in "A Tale of Two Cities" to highlight the conditions of the French Revolution?答案：Charles Dickens uses social commentary in "A Tale of Two Cities" to highlight the stark contrasts between thelives of the poor and the rich during the French Revolution. The novel illustrates the injustices and suffering that ledto the revolution, as well as the extreme violence that ensued.四、论述题9. Discuss the role of setting in "The Lord of the Rings" trilogy by J.R.R. Tolkien and how it contributes to the development of the story.答案：In "The Lord of the Rings" trilogy, the setting plays a crucial role in the development of the story. Middle-earth, with its diverse landscapes, serves as a backdrop that mirrors the internal struggles of the characters. The journey through different regions, such as the dark forest of Mirkwood or the desolate plains of Mordor, not only provides a physical challenge but also symbolizes the moral and psychological trials the characters must face. The setting is integral to the plot, influencing the characters' decisions and the unfolding of the narrative.10. Analyze the character development of Holden Caulfield in J.D. Salinger's "The Catcher in the Rye" and explain how his experiences contribute to his growth.答案：Holden Caulfield, the protagonist of "The Catcherin the Rye," undergoes significant character development throughout the novel. Initially portrayed as a disillusioned and rebellious teenager, Holden's experiences with various people and situations gradually force him to confront his own insecurities and the harsh realities of the adult world. His interactions with his sister Phoebe, his former teacher Mr. Antolini, and his encounters with strangers in New York Cityall contribute to his understanding of human nature and his place in society. By the end of the novel, Holden shows signs of maturity and a deeper appreciation for the complexities of life, indicating a significant shift from his earlier naive and cynical perspective.。

2006年12月b卷六级听力

2006年12月b卷六级听力英文回答：The passage is an interview between a reporter and a spokesperson for the American Cancer Society. The reporter asks the spokesperson about the organization's fundraising efforts, the latest advances in cancer research, and the challenges that the organization faces.The spokesperson begins by providing an overview of the American Cancer Society's mission and goals. She explains that the organization is dedicated to fighting cancer through research, education, and patient services. She then discusses the organization's fundraising efforts, emphasizing the importance of donations from individuals and businesses.The spokesperson goes on to describe the latest advances in cancer research. She mentions the development of new drugs and treatments, as well as the progress thathas been made in understanding the genetic basis of cancer. She also discusses the organization's work in the area of cancer prevention, highlighting the importance of healthy lifestyles and early detection.Finally, the spokesperson discusses the challenges that the American Cancer Society faces. She mentions the rising costs of cancer care, the need for increased funding for research, and the challenges of reaching underserved populations. However, she expresses optimism about the future, emphasizing the organization's commitment tofighting cancer until it is eliminated.中文回答：这篇采访主要围绕美国癌症协会展开，涉及了该组织的筹款活动、癌症研究的最新进展以及所面临的挑战。

高中英语B4U1句子翻译题

B4U1：句子翻译1.这位教授获得诺贝尔奖，主要因为他发明的医疗设备对人类健康至关重要。

（be awarded the Nobel Prize；be vital to）2.这位政治家说，他上台后将致力于发展经济。

（commit oneself to；come to power）3.显然，这种从植物中获取的液体具有显著的医疗特性。

（obtained from plants；remarkable medical properties）4.这位小说家具有超凡的创作天赋，写过无数充满激情的小说。

（extraordinary creative genius；be full of passion）5.他永远不会承认失败，他的目标是发现导致这种疾病的物质。

（acknowledge defeat；his objective is）6.通过分析和评估提取物，她得出结论，煮沸这种液体显然会破坏其医疗性能。

（by analysing and evaluating the extract；draw a conclusion that）7.他坚持在任何情况下都要完成这项科学研究。

（insist on;under any circumstances)8.从他的表情我可以推断，他自从担任律师以来遭遇到了很多麻烦。

（infer from his expression；take up a position as a lawyer)9．我想写一篇草稿，来总结理论联系实际的重要性。

（write a draft;sum up) 10．由于污染，地球正在逐渐变暖。

(as a consequence of, gradually get warmer)Keys:1.The professor has been awarded the Nobel Prize mostly because the medical device he invented is vital to human health.2. The politician said he would commit himself to developing the economy when he came to power.3. Apparently, this liquid obtained from plants has remarkable medical properties.4.The novelist has extraordinary creative genius and has written numerous novels that are full of passion.5. He will never acknowledge defeat,and his objective is to discover the substance that has caused the disease.6. By analyzing and evaluating the extract, she drew a conclusion that boiling the liquid would apparently destroy its medical properties.7. He insisted on completing the scientific research under any circumstances.8.I can infer from his expression that he has encountered a lot of trouble since he took up a position as a lawyer.9.I'd like to write a draft to sum up the importance of combining theory with practice.10. As a consequence of pollution,the earth is gradually getting warmer.。

Universities in Evolutionary Systems(系统变革中的大学)

Universities in Evolutionary Systems of InnovationMarianne van der Steen and Jurgen EndersThis paper criticizes the current narrow view on the role of universities in knowledge-based economies.We propose to extend the current policy framework of universities in national innovation systems(NIS)to a more dynamic one,based on evolutionary economic principles. The main reason is that this dynamic viewﬁts better with the practice of innovation processes. We contribute on ontological and methodological levels to the literature and policy discussions on the effectiveness of university-industry knowledge transfer and the third mission of uni-versities.We conclude with a discussion of the policy implications for the main stakeholders.1.IntroductionU niversities have always played a major role in the economic and cultural devel-opment of countries.However,their role and expected contribution has changed sub-stantially over the years.Whereas,since1945, universities in Europe were expected to con-tribute to‘basic’research,which could be freely used by society,in recent decades they are expected to contribute more substantially and directly to the competitiveness ofﬁrms and societies(Jaffe,2008).Examples are the Bayh–Dole Act(1982)in the United States and in Europe the Lisbon Agenda(2000–2010) which marked an era of a changing and more substantial role for universities.However,it seems that this‘new’role of universities is a sort of universal given one(ex post),instead of an ex ante changing one in a dynamic institutional environment.Many uni-versities are expected nowadays to stimulate a limited number of knowledge transfer activi-ties such as university spin-offs and university patenting and licensing to demonstrate that they are actively engaged in knowledge trans-fer.It is questioned in the literature if this one-size-ﬁts-all approach improves the usefulness and the applicability of university knowledge in industry and society as a whole(e.g.,Litan et al.,2007).Moreover,the various national or regional economic systems have idiosyncratic charac-teristics that in principle pose different(chang-ing)demands towards universities.Instead of assuming that there is only one‘optimal’gov-ernance mode for universities,there may bemultiple ways of organizing the role of univer-sities in innovation processes.In addition,we assume that this can change over time.Recently,more attention in the literature hasfocused on diversity across technologies(e.g.,King,2004;Malerba,2005;Dosi et al.,2006;V an der Steen et al.,2008)and diversity offormal and informal knowledge interactionsbetween universities and industry(e.g.,Cohenet al.,1998).So far,there has been less atten-tion paid to the dynamics of the changing roleof universities in economic systems:how dothe roles of universities vary over time andwhy?Therefore,this article focuses on the onto-logical premises of the functioning of univer-sities in innovation systems from a dynamic,evolutionary perspective.In order to do so,we analyse the role of universities from theperspective of an evolutionary system ofinnovation to understand the embeddednessof universities in a dynamic(national)systemof science and innovation.The article is structured as follows.InSection2we describe the changing role ofuniversities from the static perspective of anational innovation system(NIS),whereasSection3analyses the dynamic perspective ofuniversities based on evolutionary principles.Based on this evolutionary perspective,Section4introduces the characteristics of a LearningUniversity in a dynamic innovation system,summarizing an alternative perception to thestatic view of universities in dynamic economicsystems in Section5.Finally,the concludingVolume17Number42008doi:10.1111/j.1467-8691.2008.00496.x©2008The AuthorsJournal compilation©2008Blackwell Publishingsection discusses policy recommendations for more effective policy instruments from our dynamic perspective.2.Static View of Universities in NIS 2.1The Emergence of the Role of Universities in NISFirst we start with a discussion of the literature and policy reports on national innovation system(NIS).The literature on national inno-vation systems(NIS)is a relatively new and rapidly growingﬁeld of research and widely used by policy-makers worldwide(Fagerberg, 2003;Balzat&Hanusch,2004;Sharif,2006). The NIS approach was initiated in the late 1980s by Freeman(1987),Dosi et al.(1988)and Lundvall(1992)and followed by Nelson (1993),Edquist(1997),and many others.Balzat and Hanusch(2004,p.196)describe a NIS as‘a historically grown subsystem of the national economy in which various organizations and institutions interact with and inﬂuence one another in the carrying out of innovative activity’.It is about a systemic approach to innovation,in which the interaction between technology,institutions and organizations is central.With the introduction of the notion of a national innovation system,universities were formally on the agenda of many innovation policymakers worldwide.Clearly,the NIS demonstrated that universities and their interactions with industry matter for innova-tion processes in economic systems.Indeed, since a decade most governments acknowl-edge that interactions between university and industry add to better utilization of scienti-ﬁc knowledge and herewith increase the innovation performance of nations.One of the central notions of the innovation system approach is that universities play an impor-tant role in the development of commercial useful knowledge(Edquist,1997;Sharif, 2006).This contrasts with the linear model innovation that dominated the thinking of science and industry policy makers during the last century.The linear innovation model perceives innovation as an industry activity that‘only’utilizes fundamental scientiﬁc knowledge of universities as an input factor for their innovative activities.The emergence of the non-linear approach led to a renewed vision on the role–and expectations–of universities in society. Some authors have referred to a new social contract between science and society(e.g., Neave,2000).The Triple Helix(e.g.,Etzkowitz &Leydesdorff,1997)and the innovation system approach(e.g.,Lundvall,1988)and more recently,the model of Open Innovation (Chesbrough,2003)demonstrated that innova-tion in a knowledge-based economy is an inter-active process involving many different innovation actors that interact in a system of overlapping organizationalﬁelds(science, technology,government)with many interfaces.2.2Static Policy View of Universities in NIS Since the late1990s,the new role of universi-ties in NIS thinking emerged in a growing number of policy studies(e.g.,OECD,1999, 2002;European Commission,2000).The con-tributions of the NIS literature had a large impact on policy makers’perception of the role of universities in the national innovation performance(e.g.,European Commission, 2006).The NIS approach gradually replaced linear thinking about innovation by a more holistic system perspective on innovations, focusing on the interdependencies among the various agents,organizations and institutions. NIS thinking led to a structurally different view of how governments can stimulate the innovation performance of a country.The OECD report of the national innovation system (OECD,1999)clearly incorporated these new economic principles of innovation system theory.This report emphasized this new role and interfaces of universities in knowledge-based economies.This created a new policy rationale and new awareness for technology transfer policy in many countries.The NIS report(1999)was followed by more attention for the diversity of technology transfer mecha-nisms employed in university-industry rela-tions(OECD,2002)and the(need for new) emerging governance structures for the‘third mission’of universities in society,i.e.,patent-ing,licensing and spin-offs,of public research organizations(OECD,2003).The various policy studies have in common that they try to describe and compare the most important institutions,organizations, activities and interactions of public and private actors that take part in or inﬂuence the innovation performance of a country.Figure1 provides an illustration.Theﬁgure demon-strates the major building blocks of a NIS in a practical policy setting.It includesﬁrms,uni-versities and other public research organiza-tions(PROs)involved in(higher)education and training,science and technology.These organizations embody the science and tech-nology capabilities and knowledge fund of a country.The interaction is represented by the arrows which refer to interactive learn-ing and diffusion of knowledge(Lundvall,Volume17Number42008©2008The AuthorsJournal compilation©2008Blackwell Publishing1992).1The building block ‘Demand’refers to the level and quality of demand that can be a pull factor for ﬁrms to innovate.Finally,insti-tutions are represented in the building blocks ‘Framework conditions’and ‘Infrastructure’,including various laws,policies and regula-tions related to science,technology and entre-preneurship.It includes a very broad array of policy issues from intellectual property rights laws to ﬁscal instruments that stimulate labour mobility between universities and ﬁrms.The ﬁgure demonstrates that,in order to improve the innovation performance of a country,the NIS as a whole should be conducive for innovative activities in acountry.Since the late 1990s,the conceptual framework as represented in Figure 1serves as a dominant design for many comparative studies of national innovation systems (Polt et al.,2001;OECD,2002).The typical policy benchmark exercise is to compare a number of innovation indicators related to the role of university-industry interactions.Effective performance of universities in the NIS is judged on a number of standardized indica-tors such as the number of spin-offs,patents and licensing.Policy has especially focused on ‘getting the incentives right’to create a generic,good innovative enhancing context for ﬁrms.Moreover,policy has also inﬂu-enced the use of speciﬁc ‘formal’transfer mechanisms,such as university patents and university spin-offs,to facilitate this collabo-ration.In this way best practice policies are identiﬁed and policy recommendations are derived:the so-called one-size-ﬁts-all-approach.The focus is on determining the ingredients of an efﬁcient benchmark NIS,downplaying institutional diversity and1These organizations that interact with each other sometimes co-operate and sometimes compete with each other.For instance,ﬁrms sometimes co-operate in certain pre-competitive research projects but can be competitors as well.This is often the case as well withuniversities.Figure 1.The Benchmark NIS Model Source :Bemer et al.(2001).Volume 17Number 42008©2008The AuthorsJournal compilation ©2008Blackwell Publishingvariety in the roles of universities in enhanc-ing innovation performance.The theoretical contributions to the NIS lit-erature have outlined the importance of insti-tutions and institutional change.However,a further theoretical development of the ele-ments of NIS is necessary in order to be useful for policy makers;they need better systemic NIS benchmarks,taking systematically into account the variety of‘national idiosyncrasies’. Edquist(1997)argues that most NIS contribu-tions are more focused onﬁrms and technol-ogy,sometimes reducing the analysis of the (national)institutions to a left-over category (Geels,2005).Following Hodgson(2000), Nelson(2002),Malerba(2005)and Groenewe-gen and V an der Steen(2006),more attention should be paid to the institutional idiosyncra-sies of the various systems and their evolution over time.This creates variety and evolving demands towards universities over time where the functioning of universities and their interactions with the other part of the NIS do evolve as well.We suggest to conceptualize the dynamics of innovation systems from an evolutionary perspective in order to develop a more subtle and dynamic vision on the role of universities in innovation systems.We emphasize our focus on‘evolutionary systems’instead of national innovation systems because for many universities,in particular some science-based disciplinaryﬁelds such as biotechnology and nanotechnology,the national institutional environment is less relevant than the institu-tional and technical characteristics of the technological regimes,which is in fact a‘sub-system’of the national innovation system.3.Evolutionary Systems of Innovation as an Alternative Concept3.1Evolutionary Theory on Economic Change and InnovationCharles Darwin’s The Origin of Species(1859)is the foundation of modern thinking about change and evolution(Luria et al.,1981,pp. 584–7;Gould,1987).Darwin’s theory of natural selection has had the most important consequences for our perception of change. His view of evolution refers to a continuous and gradual adaptation of species to changes in the environment.The idea of‘survival of theﬁttest’means that the most adaptive organisms in a population will survive.This occurs through a process of‘natural selection’in which the most adaptive‘species’(organ-isms)will survive.This is a gradual process taking place in a relatively stable environment, working slowly over long periods of time necessary for the distinctive characteristics of species to show their superiority in the‘sur-vival contest’.Based on Darwin,evolutionary biology identiﬁes three levels of aggregation.These three levels are the unit of variation,unit of selection and unit of evolution.The unit of varia-tion concerns the entity which contains the genetic information and which mutates fol-lowing speciﬁc rules,namely the genes.Genes contain the hereditary information which is preserved in the DNA.This does not alter sig-niﬁcantly throughout the reproductive life-time of an organism.Genes are passed on from an organism to its successors.The gene pool,i.e.,the total stock of genetic structures of a species,only changes in the reproduction process as individuals die and are born.Par-ticular genes contribute to distinctive charac-teristics and behaviour of species which are more or less conducive to survival.The gene pool constitutes the mechanism to transmit the characteristics of surviving organisms from one generation to the next.The unit of selection is the expression of those genes in the entities which live and die as individual specimens,namely(individual) organisms.These organisms,in their turn,are subjected to a process of natural selection in the environment.‘Fit’organisms endowed with a relatively‘successful’gene pool,are more likely to pass them on to their progeny.As genes contain information to form and program the organisms,it can be expected that in a stable environment genes aiding survival will tend to become more prominent in succeeding genera-tions.‘Natural selection’,thus,is a gradual process selecting the‘ﬁttest’organisms. Finally,there is the unit of evolution,or that which changes over time as the gene pool changes,namely populations.Natural selec-tion produces changes at the level of the population by‘trimming’the set of genetic structures in a population.We would like to point out two central principles of Darwinian evolution.First,its profound indeterminacy since the process of development,for instance the development of DNA,is dominated by time at which highly improbable events happen (Boulding,1991,p.12).Secondly,the process of natural selection eliminates poorly adapted variants in a compulsory manner,since indi-viduals who are‘unﬁt’are supposed to have no way of escaping the consequences of selection.22We acknowledge that within evolutionary think-ing,the theory of Jean Baptiste Lamarck,which acknowledges in essence that acquired characteris-tics can be transmitted(instead of hereditaryVolume17Number42008©2008The AuthorsJournal compilation©2008Blackwell PublishingThese three levels of aggregation express the differences between ‘what is changing’(genes),‘what is being selected’(organisms),and ‘what changes over time’(populations)in an evolutionary process (Luria et al.,1981,p.625).According to Nelson (see for instance Nelson,1995):‘Technical change is clearly an evolutionary process;the innovation generator keeps on producing entities superior to those earlier in existence,and adjustment forces work slowly’.Technological change and innovation processes are thus ‘evolutionary’because of its characteristics of non-optimality and of an open-ended and path-dependent process.Nelson and Winter (1982)introduced the idea of technical change as an evolutionary process in capitalist economies.Routines in ﬁrms function as the relatively durable ‘genes’.Economic competition leads to the selection of certain ‘successful’routines and these can be transferred to other ﬁrms by imitation,through buy-outs,training,labour mobility,and so on.Innovation processes involving interactions between universities and industry are central in the NIS approach.Therefore,it seems logical that evolutionary theory would be useful to grasp the role of universities in innovation pro-cesses within the NIS framework.3.2Evolutionary Underpinnings of Innovation SystemsBased on the central evolutionary notions as discussed above,we discuss in this section how the existing NIS approaches have already incor-porated notions in their NIS frameworks.Moreover,we investigate to what extent these notions can be better incorporated in an evolu-tionary innovation system to improve our understanding of universities in dynamic inno-vation processes.We focus on non-optimality,novelty,the anti-reductionist methodology,gradualism and the evolutionary metaphor.Non-optimality (and Bounded Rationality)Based on institutional diversity,the notion of optimality is absent in most NIS approaches.We cannot deﬁne an optimal system of innovation because evolutionary learning pro-cesses are important in such systems and thus are subject to continuous change.The system never achieves an equilibrium since the evolu-tionary processes are open-ended and path dependent.In Nelson’s work (e.g.,1993,1995)he has emphasized the presence of contingent out-comes of innovation processes and thus of NIS:‘At any time,there are feasible entities not present in the prevailing system that have a chance of being introduced’.This continuing existence of feasible alternative developments means that the system never reaches a state of equilibrium or ﬁnality.The process always remains dynamic and never reaches an optimum.Nelson argues further that diversity exists because technical change is an open-ended multi-path process where no best solu-tion to a technical problem can be identiﬁed ex post .As a consequence technical change can be seen as a very wasteful process in capitalist economies with many duplications and dead-ends.Institutional variety is closely linked to non-optimality.In other words,we cannot deﬁne the optimal innovation system because the evolutionary learning processes that take place in a particular system make it subject to continuous change.Therefore,comparisons between an existing system and an ideal system are not possible.Hence,in the absence of any notion of optimality,a method of comparing existing systems is necessary.According to Edquist (1997),comparisons between systems were more explicit and systematic than they had been using the NIS approaches.Novelty:Innovations CentralNovelty is already a central notion in the current NIS approaches.Learning is inter-preted in a broad way.Technological innova-tions are deﬁned as combining existing knowledge in new ways or producing new knowledge (generation),and transforming this into economically signiﬁcant products and processes (absorption).Learning is the most important process behind technological inno-vations.Learning can be formal in the form of education and searching through research and development.However,in many cases,innovations are the consequence of several kinds of learning processes involving many different kinds of economic agents.According to Lundvall (1992,p.9):‘those activities involve learning-by-doing,increasing the efﬁciency of production operations,learning-characteristics as in the theory of Darwin),is acknowledged to ﬁt better with socio-economic processes of technical change and innovation (e.g.,Nelson &Winter,1982;Hodgson,2000).Therefore,our theory is based on Lamarckian evolutionary theory.However,for the purpose of this article,we will not discuss the differences between these theo-ries at greater length and limit our analysis to the fundamental evolutionary building blocks that are present in both theories.Volume 17Number 42008©2008The AuthorsJournal compilation ©2008Blackwell Publishingby-using,increasing the efﬁciency of the use of complex systems,and learning-by-interacting, involving users and producers in an interac-tion resulting in product innovations’.In this sense,learning is part of daily routines and activities in an economy.In his Learning Economy concept,Lundvall makes learning more explicit,emphasizing further that ‘knowledge is assumed as the most funda-mental resource and learning the most impor-tant process’(1992,p.10).Anti-reductionist Approach:Systems and Subsystems of InnovationSo far,NIS approaches are not yet clear and systematic in their analysis of the dynamics and change in innovation systems.Lundvall’s (1992)distinction between subsystem and system level based on the work of Boulding implicitly incorporates both the actor(who can undertake innovative activities)as well as the structure(institutional selection environment) in innovation processes of a nation.Moreover, most NIS approaches acknowledge that within the national system,there are different institu-tional subsystems(e.g.,sectors,regions)that all inﬂuence each other again in processes of change.However,an explicit analysis of the structured environment is still missing (Edquist,1997).In accordance with the basic principles of evolutionary theory as discussed in Section 3.1,institutional evolutionary theory has developed a very explicit systemic methodol-ogy to investigate the continuous interaction of actors and institutional structures in the evolution of economic systems.The so-called ‘methodological interactionism’can be per-ceived as a methodology that combines a structural perspective and an actor approach to understand processes of economic evolu-tion.Whereas the structural perspective emphasizes the existence of independent institutional layers and processes which deter-mine individual actions,the actor approach emphasizes the free will of individuals.The latter has been referred to as methodological individualism,as we have seen in neo-classical approaches.Methodological indi-vidualism will explain phenomena in terms of the rational individual(showingﬁxed prefer-ences and having one rational response to any fully speciﬁed decision problem(Hodgson, 2000)).The interactionist approach recognizes a level of analysis above the individual orﬁrm level.NIS approaches recognize that national differences exist in terms of national institu-tions,socio-economic factors,industries and networks,and so on.So,an explicit methodological interactionist approach,explicitly recognizing various insti-tutional layers in the system and subsystem in interaction with the learning agents,can improve our understanding of the evolution of innovation.Gradualism:Learning Processes andPath-DependencyPath-dependency in biology can be translated in an economic context in the form of(some-times very large)time lags between a technical invention,its transformation into an economic innovation,and the widespread diffusion. Clearly,in many of the empirical case studies of NIS,the historical dimension has been stressed.For instance,in the study of Denmark and Sweden,it has been shown that the natural resource base(for Denmark fertile land,and for Sweden minerals)and economic history,from the period of the Industrial Revolution onwards,has strongly inﬂuenced present specialization patterns(Edquist& Lundvall,1993,pp.269–82).Hence,history matters in processes of inno-vation as the innovation processes are inﬂu-enced by many institutions and economic agents.In addition,they are often path-dependent as small events are reinforced and become crucially important through processes of positive feedback,in line with evolutionary processes as discussed in Section3.1.Evolutionary MetaphorFinally,most NIS approaches do not explicitly use the biological metaphor.Nevertheless, many of the approaches are based on innova-tion theories in which they do use an explicit evolutionary metaphor(e.g.,the work of Nelson).To summarize,the current(policy)NIS approaches have already implicitly incorpo-rated some evolutionary notions such as non-optimality,novelty and gradualism.However, what is missing is a more explicit analysis of the different institutional levels of the economic system and innovation subsystems (their inertia and evolution)and how they change over time in interaction with the various learning activities of economic agents. These economic agents reside at established ﬁrms,start-upﬁrms,universities,govern-ments,undertaking learning and innovation activities or strategic actions.The explicit use of the biological metaphor and an explicit use of the methodological interactionst approach may increase our understanding of the evolu-tion of innovation systems.Volume17Number42008©2008The AuthorsJournal compilation©2008Blackwell Publishing4.Towards a Dynamic View of Universities4.1The Logic of an Endogenous‘Learning’UniversityIf we translate the methodological interaction-ist approach to the changing role of universities in an evolutionary innovation system,it follows that universities not only respond to changes of the institutional environment(government policies,business demands or changes in scientiﬁc paradigms)but universities also inﬂuence the institutions of the selection envi-ronment by their strategic,scientiﬁc and entre-preneurial actions.Moreover,these actions inﬂuence–and are inﬂuenced by–the actions of other economic agents as well.So,instead of a one-way rational response by universities to changes(as in reductionist approach),they are intertwined in those processes of change.So, universities actually function as an endogenous source of change in the evolution of the inno-vation system.This is(on an ontological level) a fundamental different view on the role of universities in innovation systems from the existing policy NIS frameworks.In earlier empirical research,we observed that universities already effectively function endogenously in evolutionary innovation system frameworks;universities as actors (already)develop new knowledge,innovate and have their own internal capacity to change,adapt and inﬂuence the institutional development of the economic system(e.g., V an der Steen et al.,2009).Moreover,univer-sities consist of a network of various actors, i.e.,the scientists,administrators at technology transfer ofﬁces(TTO)as well as the university boards,interacting in various ways with indus-try and governments and embedded in various ways in the regional,national or inter-national environment.So,universities behave in an at least partly endogenous manner because they depend in complex and often unpredictable ways on the decision making of a substantial number of non-collusive agents.Agents at universities react in continuous interaction with the learn-ing activities ofﬁrms and governments and other universities.Furthermore,the endogenous processes of technical and institutional learning of univer-sities are entangled in the co-evolution of institutional and technical change of the evo-lutionary innovation system at large.We propose to treat the learning of universities as an inseparable endogenous variable in the inno-vation processes of the economic system.In order to structure the endogenization in the system of innovation analysis,the concept of the Learning University is introduced.In thenext subsection we discuss the main character-istics of the Learning University and Section5discusses the learning university in a dynamic,evolutionary innovation system.An evolution-ary metaphor may be helpful to make theuniversity factor more transparent in theco-evolution of technical and institutionalchange,as we try to understand how variouseconomic agents interact in learning processes.4.2Characteristics of the LearningUniversityThe evolution of the involvement of universi-ties in innovation processes is a learningprocess,because(we assume that)universitypublic agents have their‘own agenda’.V ariousincentives in the environment of universitiessuch as government regulations and technol-ogy transfer policies as well as the innovativebehaviour of economic agents,compel policymakers at universities to constantly respondby adapting and improving their strategiesand policies,whereas the university scientistsare partly steered by these strategies and partlyinﬂuenced by their own scientiﬁc peers andpartly by their historically grown interactionswith industry.During this process,universityboards try to be forward-looking and tobehave strategically in the knowledge thattheir actions‘inﬂuence the world’(alsoreferred to earlier as‘intentional variety’;see,for instance,Dosi et al.,1988).‘Intentional variety’presupposes that tech-nical and institutional development of univer-sities is a learning process.University agentsundertake purposeful action for change,theylearn from experience and anticipate futurestates of the selective environment.Further-more,university agents take initiatives to im-prove and develop learning paths.An exampleof these learning agents is provided in Box1.We consider technological and institutionaldevelopment of universities as a process thatinvolves many knowledge-seeking activitieswhere public and private agents’perceptionsand actions are translated into practice.3Theinstitutional changes are the result of inter-actions among economic agents deﬁned byLundvall(1992)as interactive learning.Theseinteractions result in an evolutionary pattern3Using a theory developed in one scientiﬁc disci-pline as a metaphor in a different discipline mayresult,in a worst-case scenario,in misleading analo-gies.In the best case,however,it can be a source ofcreativity.As Hodgson(2000)pointed out,the evo-lutionary metaphor is useful for understandingprocesses of technical and institutional change,thatcan help to identify new events,characteristics andphenomena.Volume17Number42008©2008The AuthorsJournal compilation©2008Blackwell Publishing。

Kalb-Ramond interaction for a closed p-brane

f ree f ree S = Sa + Sb + dp+1ξa dp+1ξb Rab (Xa , Xb , Xa , i , Xb , j ),
(7)
with Rab = Rba , (8)
for symmetry requirement. Imposing the condition that the action (7) be stationary under the variation (4), the equation of motion is obtained as follows:
rewritten as
µ1 µ2 ...µp (p + 1)Da
σa µµ1 µ2 ...µp (−σa · σa )
1 2
= dp+1ξb
∂Rab ∂Rab µ1 µ2 ...µp µµ ...µ µ − (p + 1)Da ∂Xa ∂σa 1 p
.
(12)
We explicitly take the following form as the interaction Rab ,
µ1 µ2 ...µp (p + 1)Da
σa µµ1 µ2 ...µp (−σa · σa )
1 2
= dp+1ξb
∂Rab ∂ ∂Rab . µ − i ∂X µ ∂Xa ∂ξa a,i
(9)
3
µ Multiplying Eq.(8) by Xa , i (i = 0 ∼ p), we immediately have
µ i µ i µ i Xa ( ξ a ) → Xa (ξa ) + δXa (ξ a ), µ 1 p µ 1 p δXa (τi , ξa , ..., ξa ) = δXa (τf , ξa , ..., ξa ) = 0,

考研英语时文阅读(25)

考研时文阅读(25)"医学之父"希波克拉底说过："让食物变成你的药，让药变成你的食物。

"作为一个生于公元前五世纪的希腊人，他的智慧远远超越了他所处的时代。

如今，我们知道低脂肪而富含全麦、水果和蔬菜的饮食结构能增强我们的免疫力，并能减少癌症、心脏病和中风的发病率。

但是，这些还不完全。

新的证据显示食品可能会影响健康人的思考和感觉方式。

如果希波克拉底今天还在世的话，他也许会回顾他吃过的最后一顿饭，解释他兴奋（或忧伤）的心情。

他可能还会改变自己的饮食习惯，使自己变得更幸福或更聪明。

Can milk make you happy?Can fish make you smart?Picture yourself lying in bed, your mind in turmoil. You toss and turn, but sleep won't come. Maybe a bedtime snack would help. What should you choose? If you think first of toaster waffles or popcorn, some experts would say you're on the right track. Foods high in complex carbohydrates---such as cereals, potatoes, pasta, crackers, or rice cakes---make many people relaxed and drowsy.Missed that one? Try again. Suppose the weather's rotten, you forgot your homework, and your best friend's mad at you. What's good medicine when you're feeling low? A sugary cola or candy may give you a quick lift, but you'll crash just as quickly. Better choices may be Brazil nuts (for selenium), skim milk (for calcium), or a spinach salad (for folic acid). In research studies, all three of those nutrients have been shown to lift spirits and battle the blues.Try one more. You have a math test coming up in the afternoon. You want to be sharp, but you usually feel sleepy after lunch. Is your best choice an energy fix of fries and a shake or a broiled chicken breast and low-fat yogurt? If you pick the high-fat fries and shake, you may feel sluggish and blow that test. The protein-rich chicken and yogurt are better choices. Protein foods energize, some experts say.How does food affect mood and mind? The answer may lie in the chemistry of the brain and nervous system. Molecules called neurotransmitters are chemical messengers. They carry a nerve impulse across the gap between nerve cells. The release of neurotransmitter molecules from one neuron and their attachment to receptor sites on another keep a nerve impulse moving.Nerve impulses carry messages from the environment to the brain, for example, the pain you feel when you stub your toe. They also carry messages in the other direction, from the brain to the muscles. That's why you back away from the obstacle that initiated the pain signal and exclaim, "Ouch!""Many neurotransmitters are built from the foods we eat," says neuroscientist Eric Chudler of the University of Washington. Too little or too much of a particular nutrient in the diet can affect their production, Chudler says. For example, tryptophan from foods such as yogurt, milk, bananas, and eggs is required for the production of the neurotransmitter serotonin. Phenylalanine from beets, almonds, eggs, meat, and grains goes into making the neurotransmitter dopamine. Dozens of neurotransmitters are known; hundreds may exist. Their effects depend on their amounts and where they work in the brain. The neurotransmitter serotonin, for example, is thought to produce feelings of calmness, relaxation, and contentment. Drugs that prevent its reuptake (into the neuron that released it) are prescribed to treat depression. In at least some healthy, non-depressed people, carbohydrate foods seem to enhance serotonin production and produce similar effects. "It is the balance between different neurotransmitters that helps regulate mood," Chudler says.Proper nutrition may also enhance brainpower. Chorine is a substance similar to the B vitamins. It's found in egg yolks, whole wheat, peanuts, milk, green peas, liver, beans, seafood, and soybeans. The brain uses it to make the neurotransmitter acetylcholine. To test the effects of chorine on memory and learning, researchers at the Massachusetts Institute of Technology gave memory tests to college students before increasing the amount of chorine in their subjects’ diets. Later, they retested. On the average, memories were better, and the students learned a list of unrelated words more easily.核心词汇picture v. 想象，设想; (常后接介词as) ，相当于imagineturmoil n. 骚动，混乱（disorder=mess）snack n. 小吃，零食；on the right track(在合适或正确的小路或轨道上)，比喻为：做某事情是对的。

2016年3月中国科学院考博英语真题试卷(题后含答案及解析)

2016年3月中国科学院考博英语真题试卷(题后含答案及解析)题型有：1. Structure and V ocabulary 2. Cloze 3. Reading Comprehension 4. English-Chinese Translation 5. WritingStructure and V ocabulary1．Google is not the only search utility in town, but it comes with such a(n) ______collection of tools to focus your search that it is the engine of choice for many of us.A．comparableB．formidableC．innumerableD．compatible正确答案：B解析：本题考查形容词的语义。

A可比较的；B强大的；C无数的；D兼容的。

该句的大意为：谷歌并非唯一的搜索工具，不过，它强大的工具集合能够专注搜索，因此谷歌是大多数人选择使用的搜索引擎。

2．The defect in David’s character has______him from advancement in his career.A．exemptedB．forbiddenC．underminedD．hindered正确答案：D解析：本题考查动词的语义。

A免除；B禁止；C破坏；D阻碍。

该句的大意为：大卫性格上的缺陷阻碍了他的事业发展。

3．The theory that business could operate totally without the aid of government has proved to be a (n) ______.A．allusionB．seclusionC．illusionD．confusion正确答案：C解析：本题考查名词的语义。

N=4 Super-Yang-Mills Theory, QCD and Collider Physics

a rXiv:h ep-th/04121v12O ct24SLAC–PUB–10739,IPPP/04/59,DCPT/04/118,UCLA/04/TEP/40Saclay/SPhT–T04/116,hep-th/0410021October,2004N =4Super-Yang-Mills Theory,QCD and Collider Physics Z.Bern a L.J.Dixon b 1 D.A.Kosower c a Department of Physics &Astronomy,UCLA,Los Angeles,CA 90095-1547,USA b SLAC,Stanford University,Stanford,CA 94309,USA,and IPPP,University of Durham,Durham DH13LE,England c Service de Physique Th´e orique,CEA–Saclay,F-91191Gif-sur-Yvette cedex,France1Introduction and Collider Physics MotivationMaximally supersymmetric (N =4)Yang-Mills theory (MSYM)is unique in many ways.Its properties are uniquely speciﬁed by the gauge group,say SU(N c ),and the value of the gauge coupling g .It is conformally invariant for any value of g .Although gravity is not present in its usual formulation,MSYMis connected to gravity and string theory through the AdS/CFT correspon-dence[1].Because this correspondence is a weak-strong coupling duality,it is diﬃcult to verify quantitatively for general observables.On the other hand, such checks are possible and have been remarkably successful for quantities protected by supersymmetry such as BPS operators[2],or when an additional expansion parameter is available,such as the number ofﬁelds in sequences of composite,large R-charge operators[3,4,5,6,7,8].It is interesting to study even more observables in perturbative MSYM,in order to see how the simplicity of the strong coupling limit is reﬂected in the structure of the weak coupling expansion.The strong coupling limit should be even simpler when the large-N c limit is taken simultaneously,as it corresponds to a weakly-coupled supergravity theory in a background with a large radius of curvature.There are diﬀerent ways to study perturbative MSYM.One approach is via computation of the anomalous dimensions of composite,gauge invariant operators[1,3,4,5,6,7,8].Another possibility[9],discussed here,is to study the scattering amplitudes for(regulated)plane-wave elementaryﬁeld excitations such as gluons and gluinos.One of the virtues of the latter approach is that perturbative MSYM scat-tering amplitudes share many qualitative properties with QCD amplitudes in the regime probed at high-energy colliders.Yet the results and the computa-tions(when organized in the right way)are typically signiﬁcantly simpler.In this way,MSYM serves as a testing ground for many aspects of perturbative QCD.MSYM loop amplitudes can be considered as components of QCD loop amplitudes.Depending on one’s point of view,they can be considered either “the simplest pieces”(in terms of the rank of the loop momentum tensors in the numerator of the amplitude)[10,11],or“the most complicated pieces”in terms of the degree of transcendentality(see section6)of the special functions entering theﬁnal results[12].As discussed in section6,the latter interpreta-tion links recent three-loop anomalous dimension results in QCD[13]to those in the spin-chain approach to MSYM[5].The most direct experimental probes of short-distance physics are collider experiments at the energy frontier.For the next decade,that frontier is at hadron colliders—Run II of the Fermilab Tevatron now,followed by startup of the CERN Large Hadron Collider in2007.New physics at colliders always contends with Standard Model backgrounds.At hadron colliders,all physics processes—signals and backgrounds—are inherently QCD processes.Hence it is important to be able to predict them theoretically as precisely as possi-ble.The cross section for a“hard,”or short-distance-dominated processes,can be factorized[14]into a partonic cross section,which can be computed order by order in perturbative QCD,convoluted with nonperturbative but measur-able parton distribution functions(pdfs).For example,the cross section for producing a pair of jets(plus anything else)in a p¯p collision is given byσp¯p→jjX(s)= a,b1 0dx1dx2f a(x1;µF)¯f b(x2;µF)×ˆσab→jjX(sx1x2;µF,µR;αs(µR)),(1)where s is the squared center-of-mass energy,x1,2are the longitudinal(light-cone)fractions of the p,¯p momentum carried by partons a,b,which may be quarks,anti-quarks or gluons.The experimental deﬁnition of a jet is an in-volved one which need not concern us here.The pdf f a(x,µF)gives the prob-ability forﬁnding parton a with momentum fraction x inside the proton; similarly¯f b is the probability forﬁnding parton b in the antiproton.The pdfs depend logarithmically on the factorization scaleµF,or transverse resolution with which the proton is examined.The Mellin moments of f a(x,µF)are for-ward matrix elements of leading-twist operators in the proton,renormalized at the scaleµF.The quark distribution function q(x,µ),for example,obeys 10dx x j q(x,µ)= p|[¯qγ+∂j+q](µ)|p .2Ingredients for a NNLO CalculationMany hadron collider measurements can beneﬁt from predictions that are accurate to next-to-next-to-leading order(NNLO)in QCD.Three separate ingredients enter such an NNLO computation;only the third depends on the process:(1)The experimental value of the QCD couplingαs(µR)must be determinedat one value of the renormalization scaleµR(for example m Z),and its evolution inµR computed using the3-loopβ-function,which has been known since1980[15].(2)The experimental values for the pdfs f a(x,µF)must be determined,ide-ally using predictions at the NNLO level,as are available for deep-inelastic scattering[16]and more recently Drell-Yan production[17].The evolu-tion of pdfs inµF to NNLO accuracy has very recently been completed, after a multi-year eﬀort by Moch,Vermaseren and Vogt[13](previously, approximations to the NNLO kernel were available[18]).(3)The NNLO terms in the expansion of the partonic cross sections must becomputed for the hadronic process in question.For example,the parton cross sections for jet production has the expansion,ˆσab→jjX=α2s(A+αs B+α2s C+...).(2)The quantities A and B have been known for over a decade[19],but C has not yet been computed.Figure 1.LHC Z production [22].•real ×real:×•virtual ×real:×•virtual ×virtual:×•doubly-virtual ×real:×Figure 2.Purely gluonic contributionsto ˆσgg →jjX at NNLO.Indeed,the NNLO terms are unknown for all but a handful of collider puting a wide range of processes at NNLO is the goal of a large amount of recent eﬀort in perturbative QCD [20].As an example of the im-proved precision that could result from this program,consider the production of a virtual photon,W or Z boson via the Drell-Yan process at the Tevatron or LHC.The total cross section for this process was ﬁrst computed at NNLO in 1991[21].Last year,the rapidity distribution of the vector boson also be-came available at this order [17,22],as shown in ﬁg.1.The rapidity is deﬁned in terms of the energy E and longitudinal momentum p z of the vector boson in the center-of-mass frame,Y ≡1E −p z .It determines where the vector boson decays within the detector,or outside its acceptance.The rapidity is sensitive to the x values of the incoming partons.At leading order in QCD,x 1=e Y m V /√s ,where m V is the vector boson mass.The LHC will produce roughly 100million W s and 10million Z s per year in detectable (leptonic)decay modes.LHC experiments will be able to map out the curve in ﬁg.1with exquisite precision,and use it to constrain the parton distributions —in the same detectors that are being used to search for new physics in other channels,often with similar q ¯q initial states.By taking ratios of the other processes to the “calibration”processes of single W and Z production,many experimental uncertainties,including those associated with the initial state parton distributions,drop out.Thus ﬁg.1plays a role as a “partonic luminosity monitor”[23].To get the full beneﬁt of the remarkable experimental precision,though,the theory uncertainty must approach the 1%level.As seen from the uncertainty bands in the ﬁgure,this precision is only achievable at NNLO.The bands are estimated by varying the arbitrary renormalization and factorization scales µR and µF (set to a common value µ)from m V /2to 2m V .A computation to all orders in αs would have no dependence on µ.Hence the µ-dependence of a ﬁxed order computation is related to the size of the missing higher-order terms in the series.Althoughsub-1%uncertainties may be special to W and Z production at the LHC, similar qualitative improvements in precision will be achieved for many other processes,such as di-jet production,as the NNLO terms are completed.Even within the NNLO terms in the partonic cross section,there are several types of ingredients.This feature is illustrated inﬁg.2for the purely gluonic contributions to di-jet production,ˆσgg→jjX.In theﬁgure,individual Feynman graphs stand for full amplitudes interfered(×)with other amplitudes,in order to produce contributions to a cross section.There may be2,3,or4partons in theﬁnal state.Just as in QED it is impossible to deﬁne an outgoing electron with no accompanying cloud of soft photons,also in QCD sensible observables require sums overﬁnal states with diﬀerent numbers of partons.Jets,for example,are deﬁned by a certain amount of energy into a certain conical region.At leading order,that energy typically comes from a single parton, but at NLO there may be two partons,and at NNLO three partons,within the jet cone.Each line inﬁg.2results in a cross-section contribution containing severe infrared divergences,which are traditionally regulated by dimensional regula-tion with D=4−2ǫ.Note that this regulation breaks the classical conformal invariance of QCD,and the classical and quantum conformal invariance of N=4super-Yang-Mills theory.Each contribution contains poles inǫranging from1/ǫ4to1/ǫ.The poles in the real contributions come from regions ofphase-space where the emitted gluons are soft and/or collinear.The poles in the virtual contributions come from similar regions of virtual loop integra-tion.The virtual×real contribution obviously has a mixture of the two.The Kinoshita-Lee-Nauenberg theorem[24]guarantees that the poles all cancel in the sum,for properly-deﬁned,short-distance observables,after renormal-izing the coupling constant and removing initial-state collinear singularities associated with renormalization of the pdfs.A critical ingredient in any NNLO prediction is the set of two-loop ampli-tudes,which enter the doubly-virtual×real interference inﬁg.2.Such ampli-tudes require dimensionally-regulated all-massless two-loop integrals depend-ing on at least one dimensionless ratio,which were only computed beginning in 1999[25,26,27].They also receive contributions from many Feynman diagrams, with lots of gauge-dependent cancellations between them.It is of interest to develop more eﬃcient,manifestly gauge-invariant methods for combining di-agrams,such as the unitarity or cut-based method successfully applied at one loop[10]and in the initial two-loop computations[28].i,ij+ i iFigure3.Illustration of soft-collinear(left)and pure-collinear(right)one-loop di-vergences.3N=4Super-Yang-Mills Theory as a Testing Ground for QCDN=4super-Yang-Mills theory serves an excellent testing ground for pertur-bative QCD methods.For n-gluon scattering at tree level,the two theories in fact give identical predictions.(The extra fermions and scalars of MSYM can only be produced in pairs;hence they only appear in an n-gluon ampli-tude at loop level.)Therefore any consequence of N=4supersymmetry,such as Ward identities among scattering amplitudes[29],automatically applies to tree-level gluonic scattering in QCD[30].Similarly,at tree level Witten’s topological string[31]produces MSYM,but implies twistor-space localization properties for QCD tree amplitudes.(Amplitudes with quarks can be related to supersymmetric amplitudes with gluinos using simple color manipulations.)3.1Pole Structure at One and Two LoopsAt the loop-level,MSYM becomes progressively more removed from QCD. However,it can still illuminate general properties of scattering amplitudes,in a calculationally simpler arena.Consider the infrared singularities of one-loop massless gauge theory amplitudes.In dimensional regularization,the leading singularity is1/ǫ2,arising from virtual gluons which are both soft and collinear with respect to a second gluon or another massless particle.It can be char-acterized by attaching a gluon to any pair of external legs of the tree-level amplitude,as in the left graph inﬁg.3.Up to color factors,this leading diver-gence is the same for MSYM and QCD.There are also purely collinear terms associated with individual external lines,as shown in the right graph inﬁg.3. The pure-collinear terms have a simpler form than the soft terms,because there is less tangling of color indices,but they do diﬀer from theory to theory.The full result for one-loop divergences can be expressed as an operator I(1)(ǫ) which acts on the color indices of the tree amplitude[32].Treating the L-loop amplitude as a vector in color space,|A(L)n ,the one-loop result is|A(1)n =I(1)(ǫ)|A(0)n +|A(1),ﬁnn ,(3)where |A (1),ﬁn nis ﬁnite as ǫ→0,and I (1)(ǫ)=1Γ(1−ǫ)n i =1n j =i T i ·T j 1T 2i 1−s ij ǫ,(4)where γis Euler’s constant and s ij =(k i +k j )2is a Mandelstam invariant.The color operator T i ·T j =T a i T a j and factor of (µ2R /(−s ij ))ǫarise from softgluons exchanged between legs i and j ,as in the left graph in ﬁg.3.The pure 1/ǫpoles terms proportional to γi have been written in a symmetric fashion,which slightly obscures the fact that the color structure is actually simpler.We can use the equation which represents color conservation in the color-space notation, n j =1T j =0,to simplify the result.At order 1/ǫwe may neglect the (µ2R /(−s ij ))ǫfactor in the γi terms,and we have n j =i T i ·T j γi /T 2i =−γi .So the color structure of the pure 1/ǫterm is actually trivial.For an n -gluon amplitude,the factor γi is set equal to its value for gluons,which turns out to be γg =b 0,the one-loop coeﬃcient in the β-function.Hence the pure-collinear contribution vanishes for MSYM,but not for QCD.The divergences of two-loop amplitudes can be described in the same for-malism [32].The relation to soft-collinear factorization has been made more transparent by Sterman and Tejeda-Yeomans,who also predicted the three-loop behavior [33].Decompose the two-loop amplitude |A (2)n as|A (2)n =I (2)(ǫ)|A (0)n +I (1)(ǫ)|A (1)n +|A (2),ﬁn n,(5)where |A (2),ﬁn n is ﬁnite as ǫ→0and I (2)(ǫ)=−1ǫ+e −ǫγΓ(1−2ǫ)ǫ+K I (1)(2ǫ)+e ǫγT 2i µ22C 2A ,(8)where C A =N c is the adjoint Casimir value.The quantity ˆH(2)has non-trivial,but purely subleading-in-N c ,color structure.It is associated with soft,rather than collinear,momenta [37,33],so it is theory-independent,up to color factors.An ansatz for it for general n has been presented recently [38].3.2Recycling Cuts in MSYMAn eﬃcient way to compute loop amplitudes,particularly in theories with a great deal of supersymmetry,is to use unitarity and reconstruct the am-plitude from its cuts [10,38].For the four-gluon amplitude in MSYM,the two-loop structure,and much of the higher-loop structure,follows from a sim-ple property of the one-loop two-particle cut in this theory.For simplicity,we strip the color indices oﬀof the four-point amplitude A (0)4,by decomposing it into color-ordered amplitudes A (0)4,whose coeﬃcients are traces of SU(N c )generator matrices (Chan-Paton factors),A (0)4(k 1,a 1;k 2,a 2;k 3,a 3;k 4,a 4)=g 2 ρ∈S 4/Z 4Tr(T a ρ(1)T a ρ(2)T a ρ(3)T a ρ(4))×A (0)4(k ρ(1),k ρ(2),k ρ(3),k ρ(4)).(9)The two-particle cut can be written as a product of two four-point color-ordered amplitudes,summed over the pair of intermediate N =4states S,S ′crossing the cut,which evaluates toS,S ′∈N =4A (0)4(k 1,k 2,ℓS ,−ℓ′S ′)×A (0)4(ℓ′S ′,−ℓS ,k 3,k 4)=is 12s 23A (0)4(k 1,k 2,k 3,k 4)×1(ℓ−k 3)2,(10)where ℓ′=ℓ−k 1−k 2.This equation is also shown in ﬁg.4.The scalar propagator factors in eq.(10)are depicted as solid vertical lines in the ﬁgure.The dashed line indicates the cut.Thus the cut reduces to the cut of a scalar box integral,deﬁned byI D =4−2ǫ4≡ d 4−2ǫℓℓ2(ℓ−k 1)2(ℓ−k 1−k 2)2(ℓ+k 4)2.(11)One of the virtues of eq.(10)is that it is valid for arbitrary external states in the N =4multiplet,although only external gluons are shown in ﬁg.4.Therefore it can be re-used at higher loop order,for example by attaching yet another tree to the left.N =41234=i s 12s 231234Figure 4.The one-loop two-particle cuts for the four-point amplitude in MSYM reduce to the tree amplitude multiplied by a cut scalar box integral (for any set of four external states).i 2s 12s121234+s 121234+perms Figure 5.The two-loop gg →gg amplitude in MSYM [11,39].The blob on theright represents the color-ordered tree amplitude A (0)4.(The quantity s 12s 23A (0)4transforms symmetrically under gluon interchange.)In the the brackets,black linesare kinematic 1/p 2propagators,with scalar (φ3)vertices.Green lines are color δab propagators,with structure constant (f abc )vertices.The permutation sum is over the three cyclic permutations of legs 2,3,4,and makes the amplitude Bose symmetric.At two loops,the simplicity of eq.(10)made it possible to compute the two-loop gg →gg scattering amplitude in that theory (in terms of speciﬁc loop integrals)in 1997[11],four years before the analogous computations in QCD [36,37].All of the loop momenta in the numerators of the Feynman di-agrams can be factored out,and only two independent loop integrals appear,the planar and nonplanar scalar double box integrals.The result can be writ-ten in an appealing diagrammatic form,ﬁg.5,where the color algebra has the same form as the kinematics of the loop integrals [39].At higher loops,eq.(10)leads to a “rung rule”[11]for generating a class of (L +1)-loop contributions from L -loop contributions.The rule states that one can insert into a L -loop contribution a rung,i.e.a scalar propagator,transverse to two parallel lines carrying momentum ℓ1+ℓ2,along with a factor of i (ℓ1+ℓ2)2in the numerator,as shown in ﬁing this rule,one can construct recursively the external and loop-momentum-containing numerators factors associated with every φ3-type diagram that can be reduced to trees by a sequence of two-particle cuts,such as the diagram in ﬁg.7a .Such diagrams can be termed “iterated 2-particle cut-constructible,”although a more compact notation might be ‘Mondrian’diagrams,given their resemblance to Mondrian’s paintings.Not all diagrams can be computed in this way.The diagram in ﬁg.7b is not in the ‘Mondrian’class,so it cannot be determined from two-particle cuts.Instead,evaluation of the three-particle cuts shows that it appears with a non-vanishing coeﬃcient in the subleading-color contributions to the three-loop MSYM amplitude.ℓ1ℓ2−→i (ℓ1+ℓ2)2ℓ1ℓ2Figure 6.The rung rule for MSYM.(a)(b)Figure 7.(a)Example of a ‘Mondrian’diagram which can be determined re-cursively from the rung rule.(b)Theﬁrst non-vanishing,non-Mondrian dia-grams appear at three loops in nonplanar,subleading-color contributions.4Iterative Relation in N =4Super-Yang-Mills TheoryAlthough the two-loop gg →gg amplitude in MSYM was expressed in terms of scalar integrals in 1997[11],and the integrals themselves were computed as a Laurent expansion about D =4in 1999[25,26],the expansion of the N =4amplitude was not inspected until last fall [9],considerably after similar investigations for QCD and N =1super-Yang-Mills theory [36,37].It was found to have a quite interesting “iterative”relation,when expressed in terms of the one-loop amplitude and its square.At leading color,the L -loop gg →gg amplitude has the same single-trace color decomposition as the tree amplitude,eq.(9).Let M (L )4be the ratio of this leading-color,color-ordered amplitude to the corresponding tree amplitude,omitting also several conventional factors,A (L ),N =4planar 4= 2e −ǫγg 2N c2 M (1)4(ǫ) 2+f (ǫ)M (1)4(2ǫ)−12(ζ2)2is replaced by approximately sixpages of formulas (!),including a plethora of polylogarithms,logarithms and=+f(ǫ)−12(ζ2)2+O(ǫ)f(ǫ)=−(ζ2+ǫζ3+ǫ2ζ4+...)Figure8.Schematic depiction of the iterative relation(13)between two-loop and one-loop MSYM amplitudes.polynomials in ratios of invariants s/t,s/u and t/u[37].The polylogarithm is deﬁned byLi m(x)=∞i=1x i t Li m−1(t),Li1(x)=−ln(1−x).(14)It appears with degree m up to4at theﬁnite,orderǫ0,level;and up to degree4−i in the O(ǫ−i)terms.In the case of MSYM,identities relating these polylogarithms are needed to establish eq.(13).Although the O(ǫ0)term in eq.(13)is miraculously simple,as noted above the behavior of the pole terms is not a miracle.It is dictated in general terms by the cancellation of infrared divergences between virtual corrections and real emission[24].Roughly speaking,for this cancellation to take place,the virtual terms must resemble lower-loop amplitudes,and the real terms must resemble lower-point amplitudes,in the soft and collinear regions of loop or phase-space integration.At the level of theﬁnite terms,the iterative relation(13)can be understood in the Regge/BFKL limit where s≫t,because it then corresponds to expo-nentiation of large logarithms of s/t[40].For general values of s/t,however, there is no such argument.The relation is special to D=4,where the theory is conformally invariant. That is,the O(ǫ1)remainder terms cannot be simpliﬁed signiﬁcantly.For ex-ample,the two-loop amplitude M(2)4(ǫ)contains at O(ǫ1)all three independent Li5functions,Li5(−s/u),Li5(−t/u)and Li5(−s/t),yet[M(1)4(ǫ)]2has only the ﬁrst two of these[9].The relation is also special to the planar,leading-color limit.The subleading color-components of theﬁnite remainder|A(2),ﬁnn deﬁned by eq.(5)show no signiﬁcant simpliﬁcation at all.For planar amplitudes in the D→4limit,however,there is evidence that an identical relation also holds for an arbitrary number n of external legs, at least for certain“maximally helicity-violating”(MHV)helicity amplitudes. This evidence comes from studying the limits of two-loop amplitudes as two of the n gluon momenta become collinear[9,38,41].(Indeed,it was by analyzing these limits that the relation for n=4wasﬁrst uncovered.)The collinear limits turn out to be consistent with the same eq.(13)with M4replaced by M n everywhere[9],i.e.M(2)n(ǫ)=12(ζ2)2+O(ǫ).(15)The collinear consistency does not constitute a proof of eq.(15),but in light of the remarkable properties of MSYM,it would be surprising if it were not true in the MHV case.Because the direct computation of two-loop amplitudes for n>4seems rather diﬃcult,it would be quite interesting to try to examine the twistor-space properties of eq.(15),along the lines of refs.[31,42].(The right-hand-side of eq.(15)is not completely speciﬁed at order1/ǫandǫ0for n>4.The reason is that the orderǫandǫ2terms in M(1)n(ǫ),which contribute to theﬁrst term in eq.(15)at order1/ǫandǫ0,contain the D=6−2ǫpentagon integral[43],which is not known in closed form.On the other hand, the diﬀerential equations this integral satisﬁes may suﬃce to test the twistor-space behavior.Or one may examine just theﬁnite remainder M(L),ﬁnn deﬁnedvia eq.(5).)It may soon be possible to test whether an iterative relation for planar MSYM amplitudes extends to three loops.An ansatz for the three-loop planar gg→gg amplitude,shown inﬁg.9,was provided at the same time as the two-loop re-sult,in1997[11].The ansatz is based on the“rung-rule”evaluation of the iterated2-particle cuts,plus the3-particle cuts with intermediate states in D=4;the4-particle cuts have not yet been veriﬁed.Two integrals,each be-ginning at O(ǫ−6),are required to evaluate the ansatz in a Laurent expansion about D=4.(The other two integrals are related by s↔t.)The triple ladder integral on the top line ofﬁg.9was evaluated last year by Smirnov,all the way through O(ǫ0)[44].Evaluation of the remaining integral,which contains a factor of(ℓ+k4)2in the numerator,is in progress[45];all the terms through O(ǫ−2)agree with predictions[33],up to a couple of minor corrections.5Signiﬁcance of Iterative Behavior?It is not yet entirely clear why the two-loop four-point amplitude,and prob-ably also the n-point amplitudes,have the iterative structure(15).However, one can speculate that it is from the need for the perturbative series to=i3s12s212+s223+2s12(ℓ+k4)+2s23(ℓ+k1)21Figure9.Graphical representation of the three-loop amplitude for MSYM in the planar limit.be summable into something which becomes“simple”in the planar strong-coupling limit,since that corresponds,via AdS/CFT,to a weakly-coupled supergravity theory.The fact that the relation is special to the conformal limit D→4,and to the planar limit,backs up this speculation.Obviously it would be nice to have some more information at three loops.There have been other hints of an iterative structure in the four-point correlation func-tions of chiral primary(BPS)composite operators[46],but here also the exact structure is not yet clear.Integrability has played a key role in recent higher-loop computations of non-BPS spin-chain anomalous dimensions[4,5,6,8].By imposing regularity of the BMN‘continuum’limit[3],a piece of the anoma-lous dimension matrix has even been summed to all orders in g2N c in terms of hypergeometric functions[7].The quantities we considered here—gauge-invariant,but dimensionally regularized,scattering amplitudes of color non-singlet states—are quite diﬀerent from the composite color-singlet operators usually treated.Yet there should be some underlying connection between the diﬀerent perturbative series.6Aside:Anomalous Dimensions in QCD and MSYMAs mentioned previously,the set of anomalous dimensions for leading-twist operators was recently computed at NNLO in QCD,as the culmination of a multi-year eﬀort[13]which is central to performing precise computations of hadron collider cross sections.Shortly after the Moch,Vermaseren and Vogt computation,the anomalous dimensions in MSYM were extracted from this result by Kotikov,Lipatov,Onishchenko and Velizhanin[12].(The MSYM anomalous dimensions are universal;supersymmetry implies that there is only one independent one for each Mellin moment j.)This extraction was non-trivial,because MSYM contains scalars,interacting through both gauge and Yukawa interactions,whereas QCD does not.However,Kotikov et al.noticed, from comparing NLO computations in both leading-twist anomalous dimen-sions and BFKL evolution,that the“most complicated terms”in the QCDcomputation always coincide with the MSYM result,once the gauge group representation of the fermions is shifted from the fundamental to the adjoint representation.One can deﬁne the“most complicated terms”in the x-space representation of the anomalous dimensions—i.e.the splitting kernels—as follows:Assign a logarithm or factor ofπa transcendentality of1,and a polylogarithm Li m or factor ofζm=Li m(1)a transcendentality of m.Then the most complicated terms are those with leading transcendentality.For the NNLO anomalous dimensions,this turns out to be transcendentality4.(This rule for extracting the MSYM terms from QCD has also been found to hold directly at NNLO,for the doubly-virtual contributions[38].)Strikingly,the NNLO MSYM anomalous dimension obtained for j=4by this procedure agrees with a previous result derived by assuming an integrable structure for the planar three-loop contribution to the dilatation operator[5].7Conclusions and OutlookN=4super-Yang-Mills theory is an excellent testing ground for techniques for computing,and understanding the structure of,QCD scattering amplitudes which are needed for precise theoretical predictions at high-energy colliders. One can even learn something about the structure of N=4super-Yang-Mills theory in the process,although clearly there is much more to be understood. Some open questions include:Is there any AdS/CFT“dictionary”for color non-singlet states,like plane-wave gluons?Can one recover composite operator correlation functions from any limits of multi-point scattering amplitudes?Is there a better way to infrared regulate N=4supersymmetric scattering amplitudes,that might be more convenient for approaching the AdS/CFT correspondence,such as compactiﬁcation on a three-sphere,use of twistor-space,or use of coherent external states?Further investigations of this arena will surely be fruitful.AcknowledgementsWe are grateful to the organizers of Strings04for putting together such a stim-ulating meeting.This research was supported by the US Department of En-ergy under contracts DE-FG03-91ER40662(Z.B.)and DE-AC02-76SF00515 (L.J.D.),and by the Direction des Sciences de la Mati`e re of the Commissariat `a l’Energie Atomique of France(D.A.K.).。

高考英语一轮Unit1ScienceAndScientists教师用书新选择性必修第二册

Unit 1 Science And ScientistsⅠ. 词块记单词1. severe diarrhoea 严重的腹泻2. two contradictory theories 两种对立的理论3. an infection from germs 细菌感染4. need proof 需要证据5. multiple deaths 多起死亡事件6. be to blame 该受责备，应承担责任7. the handle of the pump 水泵的把手8. show a link between A and B显示出A和B之间的联系9. in his use of maps and statistics 在他使用地图和统计数据方面10. change the thinking of the scientific community on this issue改变科学界对这个问题的看法11. announce the finding 宣布这一发现12. cast different shadows of you 投下你不同的影子13. pour it like a liquid 像液体一样倒下14. under one's leadership 在某人的领导下15. an outstanding and creative scientist 一位杰出而有创造力的科学家Ⅱ. 语境记单词1. Many people are surprised by the transformation that the company has been transformed from a family business into a multimillionpound enterprise.(transform)2. Initially, I entirely knew about the initial steps they took to create a better campus.(initial)3. Rose's father is a skilled mechanic so she has become an expert in mechanical problems about mechanically powered vehicles, too.(mechanic)4. In the time of war, lots of money will be spent on defence and many measures will be taken to defend a country from being attacked.(defend)5. As an assistant, he assisted the professor with the experiment. And his assistance made the experiment easier to do.(assistant)6. Their daughter had a gift for language while their son is a gifted pianist.(gift)7. A country, which wants to be powerful and steady, should pay attention to developing its economy steadily．(steady)8. The famous West Lake is like a brilliant pearl embedded in the beautiful and fertile shores of the East China Sea and shocks tourists worldwide with its brilliance．(brilliant)9. With solid proof(s), the lawyer can certainly prove that he is innocent.(prove)10. The subscriber was rich and generous, subscribing two million dollars to the Red Cross.(subscribe)Ⅲ. 语境记短语1. I came down (患病) with a cold that forced me to slow down my training.2. There are concerns that a new civil war may break out (爆发) if no solution is found.3. A teacher, above all (最重要的是), should know what to do with the problems appearing in class correctly.4. Thanks to (幸亏) these donations, the poorest of the poor are receiving the bestquality medicines on offer.5. I have never subscribed to (赞成) the view that schooldays are the happiest days of your life.6. Although the city preserves a good look in general(总的来说), some of its heritage was destroyed in World War Ⅱ.7. An educator who is in charge of (主管) England's exams said a review of the primary school courses would be a chance to decide if it should be taught to younger pupils.8. Why don't you negotiate directly with him and solve this issue once and for all (彻底地)?Ⅳ. 公式练句型1. 如果你不明白某件事，你可以调查、研究以及和其他人交谈，直到你把它弄明白为止。

Gauge (in)dependence and UVIR mixing

a r X i v :h e p -t h /0502198v 2 4 O c t 2005Gauge (in)dependence and UV/IRmixingM.Attems ∗,D.N.Blaschke †,S.Hohenegger ‡,M.Schweda §,S.Stricker ¶February 22,2005Institute for Theoretical Physics,Vienna University of TechnologyWiedner Hauptstrasse 8-10,A-1040Vienna,Austria§work supported by ”Fonds zur F¨o rderung der Wissenschaftlichen Forschung”(FWF)under contract P15463-N08∗†‡¶work supported by FWF under contract P15015-N08AbstractThe gauge independence in connection with the UV/IR-mixing is dis-cussed with the help of the non-commutative U(1)-gauge ﬁeld model pro-posed by A.A.Slavnov [5]with two diﬀerent gauges:the covariant gauge ﬁxing deﬁned via a gauge parameter αand the non-standard axial-gauge depending on a ﬁxed gauge direction n µ.1IntroductionIn this short letter we investigate the UV/IR mixing and its gauge(in)dependence of a non-commutative U(1)gaugeﬁeld model with the so-called Slavnov-term in two diﬀerent gauges.One possibility is the covariant gaugeﬁxing[1],another is the axial gauge[2,3].Due to the non-commutativity of the Moyal-correspondence together with the star product of two gaugeﬁelds[4]Aµ(x)⋆Aν(x)=e i˜k2 2,(3)where˜kµ=θµνkν.The contribution(3)is UV-ﬁnite but divergent for small k. Additionally,(3)is transverse with respect to kµcorresponding the gauge(BRS)-invariance and does not depend on the gauge parameterα(see Sect.2).1The model proposed by A.Slavnov[5]implies that the gaugeﬁeld propagator is transverse with respect to˜kµ.In momentum space this means˜kµ∆(k)=0.(4)µνIn order to make the modiﬁed U(1)gauge model meaningful,the validity of(4) must be guaranteed in any gaugeﬁxing procedure implying diﬀerent gaugeﬁeld propagators.Therefore,it is the aim of this short contribution to show that(4) holds for covariant gauges and also for non-standard axial gauges.The gauge(in)dependence of(3)and(4)seems to be a fundamental property of the U(1)non-commutative gauge model[8].Usually,gauge independence signals physical aspects.But neither quantities,the polarization(3)nor the condition(4),are physical objects.Relation(4)implies∆ρµ(k)Πnpρσ(k)∆σν(k)=0,(5) leading to a consistent theory at the two loop level.2Non-commutative U(1)-gauge theory at the classical levelCorresponding to the work in progress[7]we deﬁne the non-commutative U(1)-Maxwell theory in a BRS-invariant manner including also the ghost and anti-ghostﬁelds.In the sense of Slavnov one has the following classical action for a non-commutative U(1)-Maxwell theory for the covariant gaugeﬁxing procedure with the gaugeﬁeld Aµ[10]:Γ(0)= d4x −12B⋆B+B⋆∂µAµ+λcharacterized by the supersymmetric,nilpotent and non-linear BRS transforma-tions[11]sAµ=Dµc,sc=igc⋆c,s¯c=B,sB=0,sλ=ig[c∗,λ],s2φ=0,forφ={Aµ,B,c,¯c,λ}.(9) Corresponding to the BRS quantization procedure the symmetry content of(6) may be characterized by the non-linear Slavnov identity[11].Additionally,there are also the gaugeﬁxing conditionδΓ(0)δλ=12igθµν[Aµ∗,Aν]=0.(11)In order to calculate the propagator one considers the Legendre-transformation with sources jµ,j and j B:Z cbi= d4x −12B2+B∂µAµ−λ ∂µAµ+jµAµ+j B B+jλ ==Γ(0)bi+ d4x(jµAµ+j B B+jλ),(12)where we have suppressed the ghost parts.In order to calculate the propagators of the bosonic sector one has to solve the following system of equations∂µ(∂µAν−∂νAµ)+ ∂µλ−∂µB=−jν,− ∂µAµ=−j,αB+∂µAµ=−j B,(13) with the solutionsAν[jρ,j,j B]=−1− ∂ν ∂ρ ∂νj B+1( ∂µjµ+ j),(14b)B[jµ]=1For the gaugeﬁeld propagator this implies∆cµν(k)=1k2−˜kµ˜kν2B2+B∂µAµin(14c)with BnµAµ[2,3],where nµis some gauge direction.Therefore,one hasδΓ(0)4(∂µAν−∂νAµ)2+BnµAµ−λ ∂µAµ+jµAµ+j B B+jλ ,(18) with the equations of motion∂µ(∂µAν−∂νAµ)+ ∂νλ+Bnν=−jν,− ∂µAµ=−j,nµAµ=−j B.(19) The solution of(18)is given byAν[jρ,j,j B]=−1(n∂)+n2∂ν∂ρ(n∂) (∂ν ∂ρ+∂ρ ∂ν)−(n ∂)2jρ−∂ν(n∂)∂νj,(20a)λ[jµ,j]=−1(n∂)jµ ,(20b)B[jµ]=−∂µjµThe corresponding propagator of the gaugeﬁeld is∆aµν(k)=1(nk)+n2kµkν(nk)˜k2(kν˜kµ+kµ˜kν)−(n˜k)2˜k2 .(21)This horrible propagator has the following desired properties˜kµ∆aµν(k)=nµ∆aµν(k)=0.(22) Equation(22)follows from(19).The˜k independent terms of(21)are just the usual propagator in the axial gauge[3].3Pre-conclusion and outlookMotivated by the gauge independence of the non-commutative U(1)non-planar vacuum polarization at one loop level,we have shown that the transversality condition of the gauge propagator with respect to˜kµis also gauge independent. This result can be understood by the fact that the Slavnov term is gauge invariant.Unfortunately,however,it might be possible that the axial propagator(21) produces nµ-dependent IR-singularities in non-planar one loop contributions for the U(1)-vacuum polarization.But gauge or BRS-invariance demandskµΠnp,aµν(k,n)=0,(23) implying that the only possible(quadratic)IR-divergent term consistent with dimensional analysis isΠnp,aµν(k,n)∝˜kµ˜kν4SummaryContrary to the statements made in Slavnov’s paper[6]that the absence of non-integrable IR-singularities is a direct consequence of an appropriate gauge condi-tion,we have shown the gauge(in)dependence of the Slavnov trick in this letter. The non-existence of non-integrable IR-singularities is present in the covariant gauge characterized by a gauge parameterα[1]and also in the non-standard axial gauge deﬁned with the help of aﬁxed gauge direction nµ[3]. References[1]utrup,Mat.Fys.Medd.Dan.Vid.Selsk35(1967),No.11.[2]W.Kummer,Acta Phys.Austr.,14(1961)149.[3]A.Boresch,S.Emery,O.Moritsch,M.Schweda,T.Sommer,H.Zerrouki,Applications of Noncovariant Gauges in the Algebraic Renormalization Pro-cedure,World Scientiﬁc(1998),ISBN9810234562.[4]T.Filk,Divergencies in a Field Theory on Quantum Space,Phys.Lett.B376(1996)53[5]A.A.Slavnov,Consistent noncommutative quantum gauge theories?,Phys.Lett.B565(2003)246-252,hep-th/0304141.[6]A.A.Slavnov,Gauge-invariant U(1)Model in the Axial Gauge on the Non-commutative Plane,Teor.Mat.Fiz140(3)(2004)388-395.[7]D.N.Blaschke,S.Hohenegger,M.Schweda,Divergences in Non-Commuta-tive Gauge Theories with the Slavnov Term,in preparation.[8]F.Ruiz Ruiz,Gauge-ﬁxing independence of IR divergences in non-commutative U(1),perturbative tachyonic instabilities and supersymmetry, Phys.Lett.B502(2001)274-278,hep-th/0012171[9]A.Armoni,E.Lopez,UV/IR Mixing via Closed Strings and Tachyonic In-stabilities,Nucl.Phys.B632(2002)240-256,hep-th/0110113[10]C.Becchi,A.Rouet and R.Stora,Renormalization of gauge theories,Ann.Phys.(N.Y.)98(1976)287-321.[11]O.Piguet,S.P.Sorella,Algebraic Renormalization,Perturbative Renormal-ization,Symmetries and Anomalies,Lecture Notes in Physics,Springer (1995),ISBN3-540-59115.6。

2021年6月英语六级阅读每日一练(1

2021年6月英语六级阅读每日一练(1.28)Passage TwoSupporters of the biotech industry have accused an American scientist of misconduct after she testified to the New Zealand government that a genetically modified(GM) bacterium could cause serious damage if released.The New Zealand Life Sciences Network, an association of pro-GM scientists and organizations, says the view expressed by Elaine Ingham, a soil biologist at Oregon State University in Corvallis, was exaggerated and irresponsible. It has asked her university to discipline her.But Ingham stands by her comments and says the complaints are an attempt to silence her. "They're trying to cause trouble with my university and get me fired," Ingham told New Scientist.The controversy began on 1 February, when Ingham testified before New Zealand's Royal Commission on Genetic Modification, which will determine how to regulate GM organisms. Ingham claimed that a GM version of a common soil bacterium could spread and destroy plants if released into the wild. Other researchers had previously modified the bacterium to producealcohol from organic waste. But Ingham says that when she put it in soil with wheat plants, all of the plants died within a week.."We would lose terrestrial(陆生的)plants... this is an organism that is potentially deadly to the continued survival of human beings," she told the commission. She added that the U. S. Environmental Protection Agency (EPA) canceled its approval for field tests using the organism once she had told them about her research in 1999.But last week the New Zealand Life Sciences Network accused Ingham of "presenting inaccurate, careless and exaggerated information" and "generating speculative doomsday scenarios (世界末日的局面)that are not scientifically supportable". They say that her study doesn't even show that the bacteria would survive in the wild, much less kill massive numbers of plants. What's more, the network says that contrary to Ingham's claims, the EPA. was never asked to consider the organism for field trials.The EPA has not commented on the dispute. But an e-mail to the network from Janet Anderson, director of the EPA's bio pesticides (生物杀虫剂)division, says "there is no record of a review and/or clearance to field test".Ingham says EPA officials had told her that the organism was approved for field tests, but says she has few details. It's also not clear whether the organism, first engineered by a German institute for biotechnology, is still in use.Whether Ingham is right or wrong, her supporters say opponents are trying unfairly to silence her."I think her concerns should be taken seriously. She shouldn't be harassed in this way," says Ann Clarke, a plant biologist at the University of Guelph in Canada who also testified before the commission. "It's an attempt to silence the opposition."57. The passage centers on the controversy ______.A) between American and New Zealand biologists over genetic modificationB) as to whether the study of genetic modification should be continuedC) over the possible adverse effect of a GM bacterium on plantsD) about whether Elaine Ingham should be fired by her university58. Ingham insists that her testimony is based on ______.A) evidence provided by the EPA of the United StatesB) the results of an experiment she conducted herselfC) evidence from her collaborative research with German biologistsD) the results of extensive field tests in Corvallis, Oregon59. According to Janet Anderson, the EPA ______.A) has canceled its approval for field tests of the GM organismB) hasn't reviewed the timings of Ingham's researchC) has approved field tests using the GM organismD) hasn't given permission to field test the GM organism60. According to Ann Clarke, the New Zealand Life Sciences Network ______.A) should gather evidence to discredit Ingham's claimsB) should require that the research by their biologists be regulatedC) shouldn't demand that Ingham be disciplined for voicing her viewsD) shouldn't appease the opposition in such a quiet way61. Which of the following statements about Ingham is TRUE?A) Her testimony hasn't been supported by the EPA.B) Her credibility as a scientist hasn't been undermined.C) She is firmly supported by her university.D) She has made great contributions to the study of GM bacteria.57--61 CBDCA57.主旨题.第一段提及“Supporters of the biotech industry have accused an American scientist of misconduct...genetically modified (GM) bacterium could cause serious damage if released”，即一位美国科学家认为GM细菌一旦释放即可能造成严重损害，而支持GM(pro- GM)的则认为对方发言“exaggerated and irresponsible”。

初二英语阅读理解推断题单选题40题

初二英语阅读理解推断题单选题40题1. The story is about a little boy who always gets up early to help his mother with the housework. One day, he didn't get up until 9 o'clock. What can you infer?A. He was illB. He was lazy that dayC. He forgot the timeD. His mother didn't need his help答案：A。

解析：根据文章可知小男孩平时总是早起帮妈妈做家务，但是有一天他直到9点才起床，这与他平时的行为不符，在没有其他特殊提示的情况下，最有可能是生病了才导致这种情况。

2. In a passage about different countries' eating habits, it mentions that in Japan, people often eat a lot of fish. And it also says that Japanese people have a relatively low rate of heart disease. What can you infer?A. Eating fish can cause heart diseaseB. Eating fish has nothing to do with heart diseaseC. Eating fish may help reduce the risk of heart diseaseD. Japanese people don't like other foods答案：C。

解析：文章提到日本人经常吃鱼且心脏病发病率相对较低，由此可以推断出吃鱼可能有助于降低患心脏病的风险，A选项与原文意思相悖，B选项说吃鱼与心脏病无关不符合原文暗示，D选项文章未提及。

得与失考博英文作文

得与失考博英文作文The Balancing Act of Gain and Loss in Pursuing a Doctoral Degree.In the journey of academic pursuit, the path to a doctoral degree is often fraught with both gains and losses. This pursuit is not just about acquiring knowledge but also about understanding oneself, navigating challenges, and balancing personal and professional aspirations.Gains along this path are immense and diverse. Firstly, the intellectual growth and development that occurs during doctoral studies are unparalleled. Students are exposed to cutting-edge research, engage in critical thinking, andlearn to analyze complex problems from multiple perspectives. This intellectual rigor cultivates a deeper understanding of their chosen field and equips them withthe skills to make meaningful contributions to knowledgeand society.Moreover, the doctoral degree itself is a significant milestone that opens doors to various career opportunities. It signals a high level of expertise and commitment to a particular field, often leading to prestigious positions in academia, research institutions, or even industry. The network of peers and mentors that one meets during their doctoral journey is also invaluable. These relationships can lead to future collaborations, mentorships, and support systems that are crucial for professional growth.However, the road to a doctoral degree is not without its losses. The journey is often long and arduous,requiring significant time and effort. This dedication can come at a cost, such as missed social events, forgone opportunities, or even strain on personal relationships. The pressure to publish, the competitiveness of the academic world, and the constant need to prove oneself can take a toll on one's mental health and well-being.Additionally, the financial implications of pursuing a doctoral degree can be substantial. The cost of tuition, living expenses, and research expenses can accumulatequickly, often necessitating the incurrence of debt. This financial burden can cast a shadow over one's post-graduation life, affecting career choices and personal aspirations.Moreover, the nature of doctoral research often requires a significant amount of creativity and innovation. However, this creative freedom can also lead to feelings of isolation and loneliness as researchers spend long hours alone, grappling with complex problems. The fear of failure or not meeting expectations can also be a constant companion, leading to feelings of anxiety and impostor syndrome.To navigate these gains and losses, it is crucial for doctoral students to maintain a healthy balance in their lives. This involves setting realistic goals, managingtheir time effectively, and prioritizing their well-being. Seeking support from peers, mentors, and professional counselors can also be invaluable in coping with the stress and challenges of doctoral studies.In conclusion, pursuing a doctoral degree is a balancing act between gains and losses. It requires resilience, dedication, and the ability to navigate challenges. By maintaining a healthy balance in their lives and seeking support, doctoral students can ensure that this pursuit not only leads to professional success but also personal growth and fulfillment.。

关于盖比茨的英语作文

关于盖比茨的英语作文Gabby Giffords is an American politician and guncontrol advocate who has become a prominent figure in the fight for stricter gun laws in the United States. Giffords was born on June 8, 1970, in Tucson, Arizona. She began her career in public service as a member of the Arizona House of Representatives, where she served from 2001 to 2003. In 2006, she was elected to the U.S. House of Representatives, representing Arizona's 8th congressional district.Giffords quickly gained a reputation as a moderate Democrat who was willing to work across party lines to get things done. She was known for her strong support of veterans and her commitment to improving education and healthcare. However, Giffords' career was tragically cut short on January 8, 2011, when she was shot in the head during a public event in Tucson. The shooting left six people dead and 13 others injured.Despite the severity of her injuries, Giffords survivedthe attack and has since become a leading advocate for gun control. In 2013, she and her husband, retired NASA astronaut Mark Kelly, founded the organization Americansfor Responsible Solutions, which aims to promote responsible gun ownership and reduce gun violence. Giffords has also been a vocal supporter of universal background checks for gun purchases and a ban on assault weapons.In addition to her advocacy work, Giffords has also been involved in efforts to improve mental healthcare in the United States. She has spoken out about the need to address the underlying causes of gun violence, including mental illness and domestic abuse. Giffords has received numerous awards and honors for her advocacy work, including the John F. Kennedy Profile in Courage Award and the Americans for Responsible Solutions Leadership Award.Despite the challenges she has faced, Giffords remains committed to making a difference on the issue of gun violence. She has been praised for her courage and determination in the face of adversity, and she continues to inspire others to take action to prevent gun violence intheir communities. Giffords' story is a powerful reminder of the impact that one person can have on the world, and her advocacy work has helped to bring about positive change in the United States.。

管理英语3——精选推荐

管理英语3History Module: The Historical Roots of Contemporary Management PracticesTrue/False1. Organized activities and managers have been with us since the Industrial Revolution. (F; Moderate; p. 22)2. It has only been in the past several hundred years that management has undergone systematic investigation, acquired a common body of knowledge, and become a formal discipline. (T; Easy; p. 22)3. Adam Smith argued for the economic advantages that organizations and society would reap from the division of labor. (T; Easy; p. 23)4. The classical approach to management can be broken into two subcategories: scientific management and behavioral management. (F; Challenging; p. 23)5. The theory of scientific management included the concept that there was "one best way" for a job to be done. (T; Moderate; p. 23)6. Although Taylor spread his ideas to many countries, his greatest influence was on German automobile production. (F; Moderate; p. 24)7. Frank Gilbreth is probably best known for his experiments in reducing the number of motions in bricklaying. (T; Moderate; p. 25)8. Max Weber stated fourteen principles of management—fundamental or universal truths—that could be taught in schools and universities. (F; Moderate; p. 26)9. Weber's bureaucracy was characterized by division of labor, a clearly defined hierarchy, detailed rules and regulations, and impersonal relationships. (T; Challenging; p. 26)10. According to Fayol, centralization refers to the degree of which subordinates are involved in decision making. (T; Moderate; p. 27; Ex. HM-2)11. Fayol's principle that every employee should receive orders from only one superior is referred to as scalar chain.(F; Easy; p. 27; Ex. HM-2)12. Robert Owen argued that money spent on improving labor conditions was one of the best investments that business executives could make. (T; Moderate; p.28)13. Hugo Munsterberg is best known for his work on the Hawthorne Studies. (F; Moderate; p. 29)14. The most important contributions to the human resources approach to management came out of the Hawthorne studies. (T; Challenging; p. 30)15. Chester Bernard proposed ideas that abridged classical and human resources viewpoints. He believed that organizations were made up of people who had interacting social relationships. (T; Moderate; p. 29)16. Maslow argued that needs could be satisfied in different orders fordifferent people. (F; Moderate; p. 31)17. Theory X presents a negative view of people while Theory Y presents a positive view. (T; Easy; p. 31)18. The common thread that united human relations supporters was pessimism about people's capabilities. (F; Moderate; p.31)19. Operations research evolved out of mathematical and statistical solutions to military problems during World War II. (T; Moderate; p. 32)20. The common thread in the ideas of Taylor, Gilbreth, Fayol, and Weber was an increased concern for employee satisfaction. (F; Easy; p. 33)21. The application of scientific management principles contributed to raising the standard of living of entire countries. As anexample more people were able to own more homes. (T; Challenging; p. 34)22. The classical view of management treated organizations and people as machines. (T; Moderate; p. 34)23. The process approach to the study of management views organizations asa set of interrelated and interdependent parts arranged to produce a unified whole. (F; Challenging; p. 35)24. The open systems approach recognizes the dynamic interaction of the system with its environment. (T; Easy; p. 36)25. The manager's job excludes the interests of all stakeholders except those within the organization. (F; Easy; p. 36)26. Organizational survival often depends on successful interactions with the external environment. (T; Moderate; p. 36)27. Employees, customers, suppliers, labor unions, and government agencies are examples of stockholders. (F; Moderate; p.36)28. Popular contingency variables that have a significant effect on what managers do are organizational size and environmental uncertainty. (T; Moderate; p. 37; Ex. HM-5)Multiple Choice29. _____ refer(s) to the breakdown of jobs into narrow, repetitive tasks.a. Division of laborb. The Hawthorne studiesc. Separation of dutiesd. Scientific management (a; Easy; p. 23)30. Machine labor was substituted for human powera. in Adam Smith's Wealth of Nations.b. during the Industrial Revolution.c. in Weber's bureaucracy.d. in open systems. (b; Moderate; p. 23)31. The two subcategories of the classical approach to management are scientific management anda. human resource management.b. behavioral management.c. general administration theory.d. bureaucracy. (c; Moderate; p. 23)32. _____ is the term used to describe the hypotheses of the scientific management theorists and the general administrative theorists.a. Contingency approachb. Human resourcesc. Human relationsd. Classical approach (d; Easy; p. 23)33. Which of the following individuals is most closely associated with scientific management?a. Frederick Taylorb. Mary Parker Follettc. Harold Koontzd. Max Weber (a; Easy; p. 23)34. Which of the following is not one of Taylor's principles of management?a. Use science, not rule-of-thumb.b. Allocate work to workers so managers only oversee.c. Scientifically select, train, teach, and develop the worker.d. Cooperate with workers to ensure work is done according to principles of science. (b; Challenging; p. 24)35. Taylor sought to create a mental revolution by creating clear guidelines for improving production efficiency. He argued that following these principles would result in the prosperity of both _____ and _____.a. owners; managementb. management; stockholdersc. management; workersd. owners; workers (c; Moderate; p. 24)36. _____ refers to a classification scheme developed by the Gilbreths to label basic hand motions.a. Widgetb. Brick-stepc. Therbligd. G-motion (c; Easy; p. 25)37. Although they wrote during the same period, Taylor was a scientist while _____ was a practitioner.a. Weberb. Maslowc. McGregord. Fayol (d; Challenging; p. 26)38. All of the following are included in Fayol's fundamental principles of management excepta. equality.b. order.c. initiative.d. authority. (a; Moderate; p. 27; HM-2)39. All of the following are included in Fayol’s fundamental principles of management excepta. scalar chain.b. Equity.c. division of work.d. multiplicity of direction. (d; Easy; p. 27)40. Weber's ideal bureaucracy includes all of the following features excepta. division of labor.b. training.c. impersonality.d. career orientation. (b; Moderate; p. 27; HM-3)41. _____ created the field of industrial psychology.a. Max Weberb. Frederick Taylorc. Hugo Munsterbergd. David McClelland (c; Moderate; p. 29)42. Mary Parker Follet was a social philosopher who taught that organizations should be based on _____ rather than _____.a. individualism; group ethicb. ethics; profitsc. efficiency; profitsd. group ethic; individualism (d; Challenging; p.29)43. Which of the following is not true about the Hawthorne studies?a. They were initially devised to examine the effect of illumination level on worker productivity.b. Elton Mayo and his associates were the researchers associated with the studies.c. One conclusion was that group influences did not significantly affect individual behavior.d. The conclusions of the studies led to a new emphasis on the human factor in attaining organizational goals. (c; Challenging; p. 30)44. Dale Carnegie taught that the way to success was to follow all of these except:a. Make others feel important through a sincere appreciation of their efforts.b. Make a good first impression.c. Change people by praising good traits and giving the offender the opportunity to save face.d. Create a sound business plan. (d; Moderate; p. 31)45. From which focus have the contributions of team-based compensation systems, design of jobs, organizational cultures, high-performance teams, conflict management, and attitude surveys derived?a. scientific managementb. behavioral sciencec. human resourcesd. classical (c; Challenging; p. 32)46. All of the following are quantitative approaches to management excepta. optimization models.b. information models.c. linear programming.d. meta-analysis. (d; Moderate; p. 32)47. The management theory jungle was developed bya. Maslow.b. Herzberg.c. Ouchi.d. Koontz. (d; Moderate; p. 35)48. All except which of the following are components of the process approach to management?a. planningb. organizingc. controllingd. negotiating (d; Moderate; p. 35)49. Which of the following is not one of the integrative frameworks that have evolved to help organize the subject matter of management?a. process approachb. function approachc. systems approachd. contingency approach (b; Moderate; p. 35)50. Which of the following approaches is used most frequently in organizing management subject matter?a. process approachb. function approachc. systems approachd. contingency approach (a; Challenging; p.35)51. The _____ approach focuses on a set of interrelated and interdependent parts arranged in a manner that produces a unified whole.a. processb. functionc. systemsd. contingency (c; Moderate; p. 36)52. _____ are not influenced by and do not interact with their environment.a. Closed systemsb. Open systemsc. Structured systemsd. Non-structured systems (a; Easy; p. 36)53. Today it is assumed that organizations will be _____ systems.a. closedb. openc. structuredd. non-structured (b; Easy; p. 36)54. Labor unions, employees, suppliers, customers, clients, and public interest groups are all examples ofa. management constituencies.b. stockholders.c. stakeholders.d. business owners. (c; Moderate; p. 36)55. Groups that are affected by organizational decisions and policies are known asa. management constituencies.b. stockholders.c. stakeholders.d. business owners. (c; Easy; p. 36)56. Which of the following approaches recognizes differences among organizations and categorizes variables that affect an organization's performance?a. process approachb. function approachc. systems approachd. contingency approach (d; Easy; p. 37)57. Which of the following is not a variable that is considered when using the contingency approach to management?a. organization sizeb. individual differencesc. environmental uncertaintyd. management experience (d; Moderate; p. 37; Ex. HM-5)58. Focusing on the degree of uncertainty caused by politics, technology, and the economy would fall under which of the following contingency variables?a. organization sizeb. individual differencesc. environmental uncertaintyd. management experience (c; Moderate; p. 37; Ex. HM-5)。

1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。

a rXiv:h ep-ph/9611202v11Nov1996The gauge boson contributions to the radiatively corrected mass of the scalar Higgs boson in the minimal supersymmetric standard model Seung Woo Ham and Sun Kun Oh Department of Physics,Kon-Kuk University,Seoul 143-701,Korea Bjong Ro Kim III.Physikalisches.Institut.A,RWTH Aachen,D52056Aachen,Germany Abstract We derive analytic formulas for the radiatively corrected mass of the scalar Higgs boson in the framework of the minimal supersymmetric standard model (MSSM).Since the scalar-top-quark mass in our analysis include terms propor-tional to the gauge couplings in the 1-loop eﬀective potential,the radiatively corrected mass of the scalar Higgs boson partially contains the gauge boson con-tributions.At the 1-loop level,the upper bound on the lighter scalar Higgs bosonmass can be increased about 20GeV in favor of the partial contributions of the gauge bosons.Thus the improved absolute upper bound on the lighter scalar Higgs boson mass is about 150GeV.1.IntroductionThe electroweak gauge boson masses(m W,m Z)in the standard model(SM)are generated through the Higgs mechanism.Then the SM predicts a new scalar particle, the Higgs particle.But an evidence for the existence of the Higgs particle has not been experimentally observed up to now.Therefore a study for the Higgs particle is one of the most important issues in elementary particle physics at the present.In the SM only one Higgs doublet is required to give masses to quarks and leptons.Therefore there is just one scalar Higgs boson in the SM.The lower bound of about60GeV on the Higgs boson mass of the SM is estimated from the negative experiment results of LEP1.The upper bound on the Higgs boson mass of the SM is known as almost free parameter.On the other hand,supersymmetric models impose a strong constraint on the upper bound on the Higgs boson mass.In supersymmetric models,at least two Higgs doublets are required to give masses to fermions via spontaneous symmetry breaking.Hence,several Higgs bosons are present in supersymmetric models.One of the most widely studied supersymmetric models is the minimal supersym-metric standard model(MSSM).The MSSM is the simplest supersymmetric extension of the SM.The MSSM oﬀers a solution to the gauge hiearchy problem in a technical way.Its Higgs sector consists of two Higgs doublets,H1and H2.The hypercharges of two Higgs doublets are Y=−1for H1and Y=1for H2,respectively.In the MSSM, down-type quarks and leptons are generated in terms of the vacuum expectation value (v1)of H1while up-type quarks are generated in terms of the vacuum expectation value (v2)of H2.The Higgs spectra of the MSSM consists of two neutral scalar Higgs boson (h,H),one neutral pseudoscalar Higgs boson(A),a pair of charged Higgs bosons(H±).At the MSSM the tree level mass of the Higgs boson depends on only two free ually,one of two parameters is chosen to be the ratio of the vacuum expectation values of two Higgs doublets,tanβ,and the other be either the lighter scalar Higgs boson mass or the pseudoscalar Higgs boson mass.According to the tree level potential,the mass of the lighter scalar Higgs boson has to be smaller than both the Z boson mass and the pseudoscalar Higgs boson mass.Also the MSSM predicts at the tree level that the mass of the charged Higgs boson must be larger than the W boson mass.At the tree level,another distinct feature is that the Higgs boson mass posesses a symmetric property under interchange cosβ↔sinβ.It has been recently pointed out that radiative corrections give a positive con-tribution to the tree level mass of the scalar Higgs boson.Especially the dominant contribution to the tree level Higgs boson mass comes from radiative correctios due to the top-quark and scalar-top-quark loops.The radiatively corrected mass of the lighter scalar Higgs boson can be larger than both the Z boson mass and the radia-tively corrected mass of the pseudoscalar Higgs boson[1].Furthermore,the radiatively corrected mass of the charged Higgs boson can be smaller than W boson mass[2]. This means that radiative corrections to the tree level mass of the charged Higgs boson can be negative contributions.When radiative corrections to the tree level mass ofthe Higgs boson are included,the symmetric property of the neutral Higgs boson mass under interchange cos β↔sin βis broken [3].In this paper,we calculate the radiatively corrected mass of the neutral Higgs boson in the framework of the MSSM.Especially,we consider the gauge boson contributions to the neutral Higgs boson mass at the 1-loop level.That is,we take the scalar-top-quark mass which contains terms proportional to the gauge couplings in the 1-loop eﬀective potential.Then we derive analytic formulas for the radiatively corrected mass of the neutral Higgs boson.The radiatively corrected mass of the pseudoscalar Higgs boson does not changed by the inclusion of terms proportional to the gauge couplings in the scalar-top-quark mass.On the other hand,the radiatively corrected mass of the scalar Higgs boson can be improved by the inclusion of terms proportional to the gauge couplings in the scalar-top-quark mass.At the 1-loop level,the improved mass of the scalar Higgs boson partially contains the gauge boson contributions.2.The Higgs boson mass spectraIn the MSSM,the tree level Higgs potential including the soft supersymmetry (SUSY)breaking terms is given byV tree =m 21|H 1|2+m 22|H 2|2−m 23(H 1H 2+H .c .)+12|H ∗1H 2|2,(1)where g 1and g 2are the U(1)and SU(2)gauge coupling constants,respectively,andH 1H 2=H 01H 02−H −H +.We assume that m i (i =1,2,3)>0.The 1-loop eﬀective potential including the ﬁeld-dependent mass-squared matrix M 2of the scalar-top-quark [4]isV 1−loop =1Λ2−332π2M 4˜t i log M 2˜t i2 −3Λ2−3where M˜ti (i=1,2)and M t are theﬁeld-dependent scalar-top-quark masses and theﬁeld-dependent top-quark mass,respectively.Theﬁeld-dependent mass-squared of the top-quark is given byM2t=h2t|H02|2.(5) Theﬁeld-dependent mass-squared matrix of the scalar-top-quark is given as a2×2 Hermitian matrix.The eigenvalues of the Hermitian matrix are theﬁeld-dependent mass-squareds of the scalar-top-quark,M2˜t1,˜t2=h2t|H02|2+18(g21+g22)(|H01|2−|H02|2)∓2(m2Q−m2T)+(112g21)(|H01|2−|H02|2) 2+h2t|µH01+A t H0∗2|2.(7)In the above equations,h t is the top-quark Yukawa coupling,A t is the trilinear soft SUSY breaking parameter,and m Q and m T are the soft SUSY breaking scalar-quark masses.Thus the mass-squared of the top-quark is given asm2t=(h t v sinβ)2(8) and also the mass-squareds of the scalar-top-quark are given asm2˜t1,2=m2t+14m2Z cos2β∓ 13m2W−52,(9)where m˜t1≤m˜t2and m Z=(g21+g22)v2/2,m W=(g2v)2for∂φi∂φj<H01>=v1,<H02>=v2,(11)whereφi are the conventional notations for the real and imaginary parts of the Higgs ﬁelds.The soft SUSY breaking parameters m1and m2can be eliminated by the minimization conditions,∂<V>The real parts of two neutral Higgsﬁelds in M1ij lead to the mass-squared matrix of the scalar Higgs boson.The exact expression for the elements of the mass-squared matrix M S is obtained asM S11=(m A sinβ)2+(m Z cosβ)2+∆11,M S22=(m A cosβ)2+(m Z sinβ)2+∆22,M S12=−(m2A+m2Z)sinβcosβ+∆12,(13) with∆11=3128π2v2logm2˜t1m2˜t216π2v2 46m2Z2cos2βf(m2˜t1,m2˜t2)+3m2˜t1−m2˜t2log m2˜t18π2∆22g(m2˜t1,m2˜t2)−3m4tΛ2−33m2W−516π2v 4m2t m2˜t1−m2˜t2log m2˜t132π2v2 2m2t2m2Z sinβ2log m2˜t1m2˜t28π2∆1∆2g(m2˜t1,m2˜t2)+3m2Z sin2βsin2β−m2Z log m2˜t1m2˜t232π2v m2Z cosβ∆2+4m2t(m2˜t1−m2˜t2)logm2˜t1 32π2v2 46m2Z2sin2βf(m2˜t1,m2˜t2),(14)as well as∆1=m2tµ2v (m2Q−m2T)+(46m2Z)cos2β (46m2Z),∆2=m2t A t2v (m2Q−m2T)+(46m2Z)cos2β (46m2Z),(15)and alsof(m2˜t1,m2˜t2)=1Λ2−m2˜t2logm2˜t2g(m2˜t1,m2˜t2)=1m2˜t1−2(m2˜t2−m2˜t1) .(16)In the above equation,the radiatively corrected mass-squared of the pseudoscalar Higgs boson is given bym2A=m2316π2v2sin3βcosβf(m2˜t1,m2˜t2),(17)where theﬁrst term stands for the mass-squared of the pseudoscalar Higgs boson at the tree-level.Even if terms proportional to the gauge couplings in the scalar-top-quark mass are included,the radiatively corrected mass of the pseudoscalar Higgs boson does not changed.The mass-squareds of the scalar Higgs boson are obtained asm2h,H=1(T rM S)2−4det(M S) ,(18)m h≤m H.Now let us set a reasonable region in parameter space in order to obtain the nu-merical result for the neutral Higgs boson mass.The CDF and D0collaborations, respectively,predict that the top-quark mass is176±8±10and199+19−21±22GeV[5]. Therefore we take the top quark mass of175GeV.The Higgs mixing parameterµis the mass parameter introduced in the superpotential termµH1H2.The values of thefunction f(m2˜t1,m2˜t2)are always positive in our parameter setting.If we setµ·A t asa positive value,radiative corrections will be positively contributed to the tree level mass of the pseudoscalar Higgs boson.In this paper,weﬁxµas the electroweak scale, 100GeV.In our numerical analysis,the ranges of parameters are presented in Table 1.The upper limit of tanβin Table.1is given by equation,tanβ=m t/m b≈40for m t=175GeV The upper limit on the tree level mass of the pseudoscalar Higgs boson isﬁxed as950GeV in our numerical analysis.Thus m23can be increased up to1502 for tanβ=40.Experimentally supersymmetric particles are constrained to be heavier than their SM partners[6].Therefore we assume that the lower limit on the lighter scalar-top-quark mass is larger than the top-quark mass.Table I.The ranges for the MSSM parameters102≤m23≤15022≤tanβ≤40100≤m Q≤1000GeV100≤m T≤1000GeV100≤A t≤3000GeVNext let us evaluate the numerical result for the upper bound on the neutral Higgs boson mass including radiative corrections in the MSSM.In Fig.1,we plot m h includ-ing the partial contributions of the gauge bosons at the1-loop level.m h is maximizedfor the parameter space of102≤m23≤1502GeV,and100≤m Q(m T)≤1000GeV. Weﬁnd from Fig.1that m h increases as tanβincreases.That is,m h of the MSSM is always maximized as sinβ→1.Fig.2shows the upper bound on the radiatively corrected mass of the neutral Higgs boson,as a function of tanβ,for102≤m23≤1502 GeV,100≤m Q(m T)≤1000GeV,and100≤A t≤3000GeV.Of course the upper bound on the lighter scalar Higgs boson mass at the tree level is Z boson mass.The dashed curve exhibits the upper bound on the neutral Higgs boson mass without the gauge boson contributions.The solid curve exhibits the upper bound on the neutral Higgs boson mass with the partial contributions of the gauge bosons.Weﬁnd from Fig2that m A approaches m H as tanβincreases.The absolute upper bounds on m h without the gauge boson contributions and with the partial contributions of the gauge bosons is about130and150GeV for tanβ=40GeV,respectively.3.ConclusionsIn the MSSM,analytic formulas for the radiatively corrected mass of the neutral Higgs boson are derived from the1-loop eﬀective pontial.In our analysis,the scalar-top-quark mass in the1-loop eﬀective potential includes terms proportional to the gauge couplings.The radiatively corrected mass of the pseudoscalar Higgs boson does not changed by the inclusion of terms proportional to the gauge couplings in the scalar-top-quark mass[7].Radiative corrections to the tree level mass of the pseudoscalar Higgs boson leads to a positive contribution forµ·A t>0in our parameter space. Radiative corrections to the pseudoscalar Higgs boson give a positive contribution of about90GeV in its mass.The formuals for the radiatively corrected mass of the scalar Higgs boson are diﬀerent from those of other paper[7].At the1-loop level, terms proportional to gauge couplings in the scalar-top-quark mass give a signiﬁcant contribution to the scalar Higgs boson mass.Especially,the radiatively corrected mass of the lighter scalar Higgs boson can be increased by about20GeV in favor of the partial contributions of the gauge bosons.Thus we have obtained the improved absolute upper bound on the lighter scalar Higgs boson mass of about150GeV. AcknowledgementsThis work is supported in part by the Basic Science Research Institute Program, Ministry of Education,BSRI-96-2442.References[1]A.Brignole,J.Ellis,G.Ridolﬁ,and F.Zwirner,Phys.Lett.271B,123(1991);M.A.Diaz and H.E.Haber,Phys.Rev.D45,4246(1992).[2]H.E.Haber and R.Hempﬂing,Phys.Rev.Lett.66,1815(1991);J.Kodaira,Y.Yasui,and K Sasaki Phys.Rev.D50,7035(1994).[3]J.L.Lopez and D.V.Nanopoulos,Phys Lett.B266,397(1991).[4]J.Ellis,G.Ridolﬁ,and F.Zwirner,Phys.Lett.B257,83(1991).[5]CDF Collaboration,F.Abe et al.,Phys.Rev.Lett.74,2626(1995);D0Collabo-ration,S.Abachi et al.,Phys.Rev.Lett.74,2632(1995).[6]H1Collaboration,S.Aid et al,preprint,hep-ex(9605002).[7]J.Ellis,G.Ridolﬁ,and F.Zwirner,Phys.Lett.B262,477(1991).Figure CaptionsFig.1:The maximum values of m h at the1-loop level,as a function of A t,for 102≤m23≤1502GeV,100≤m Q(m T)≤1000GeV.Fig.2:The upper bound on the neutral Higgs boson mass,as a function of tanβ, for102≤m23≤1502GeV,100≤A t≤3000GeV.The dashed(solid)curve denote the upper bound on the neutral Higgs boson mass without(with)the gauge boson contributions.。