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2018年01月23日 20:06:52

Science and Technology Fundamental physics Antimatter of fact科技 基础物理 反物质研究突飞猛进Researchers at CERN have held on to anti-atoms for a full quarter of an hour欧洲核子研究中心的科研人员让反原子颗粒存在时间长达15分钟READERS who were paying attention in their maths classes may recall that quadratic equations often have two solutions, one positive and one negative.数学课上认真听讲的读者朋友或许都能想起二次方程式通常有两个解:一个是正解,另一个是负解。So when, in 1928, a British physicist called Paul Dirac solved such an equation relating to the electron, the fact that one answer described the opposite of that particle might have been brushed aside as a curiosity.因此1928年,当英国物理学家保罗·狄拉克(Paul Dirac)在解一道有关微观电子的类似方程时,得到了一个描述电子颗粒负状态的结果,该结果按照异常情况本应该予以舍弃,但实际情况并非如此。But it wasnt. Instead, Dirac interpreted it as antimatter-and, four years later, it turned up in a real experiment.狄拉克(Dirac)把这种负粒子解释为反物质,四年后,反物质在真实的实验中出现。Since then antimatter-first, anti-electrons, known as positrons, and then antiversions of all other particles of matter-has become a staple of both real science and the fictional sort.从那以后,反物质研究—首先是反电子,俗称正电子,然后到其它所有物质颗粒的反续状态—成为真实科学和虚拟科学的重要组成部分。What has not been available for study until recently, however, is entire anti-atoms.迄今为止,只有反原子还没有得到全面的研究。A handful have been made in various laboratories, and even held on to for a few seconds.但少数反原子的研究已经在不同实验室展开,有些实验室甚至让反原子存在了几秒种。But none has hung around long enough to be examined in detail because, famously, antimatter and matter annihilate each other on contact.但他们都没有能够让反原子存在更长时间以提供细节观测,众所周知,这是由于反物质和物质在接触过程中会互相湮灭。But that has now changed, with the preservation of several hundred such atoms for several minutes by Jeffrey Hangst and his colleagues at CERN, the main European particle-physics laboratory near Geneva.但现在这种情况已经得到了改观,欧洲原子核研究组织(CERN)—日内瓦附近的欧洲粒子物理研究试验室—的Jeffrey Hangst及其同事已将数百颗这种原子的生命状态持续了几分钟。The reason this is important is that Diracs equation is misleading.反原子状态不能保留的重要原因在于我们受了狄拉克(Dirac)方程式的误导。Antimatter cannot be the perfect opposite of matter, otherwise neither would exist at all.反物质与物质不可能以完全对等的反状态形式存在,否则任何一方都不可能存留。If they truly were perfect opposites, equal amounts of the two would have been made in the Big Bang, and they would have annihilated each other long since, leaving only light and other forms of electromagnetic radiation to fill the universe.如果真是那样的话,那么在宇宙大爆炸时期,它们二者生成的数量也应该相同,历经漫长的时间演化,它们早就应该互相湮灭,只留下光线和各种形式的电磁辐射充斥宇宙。That galaxies, stars and planets-and physicists to ponder such things-exist therefore means there is a subtle asymmetry between matter and antimatter, and that nature somehow favours the former.因此物理学家认为星系,恒星和行星诸如此类的事物能够存在的原因在于物质与反物质一定存在着一种微妙的非对称性,而自然界偏偏钟爱于前者。Two such asymmetries have indeed been found. But neither is big enough to explain why so much matter has survived.实际上;物质;与;反物质;的非对称性已经在两项试验中被发现,但它们的非对称程度还不足以解释为什么会有大量的;物质;存续下来。Being able to look at entire anti-atoms might give some further clue.通过观察完整的反原子,科学家或许能得到进一步的线索。Last November the ALPHA collaboration at CERN, which Dr Hangst leads, managed to put positrons into orbit around 38 antiprotons-thus creating anti-hydrogen atoms-and then held on to them in a magnetic trap for a few tenths of a second.去年11月,欧洲原子核研究组织阿尔法合作项目负责人Hangst士设法将一些正电子分别放入38颗反质子的轨道—这样就产生了反氢原子—然后让它们在电磁阱中存留零点几秒的时间。Now, as they report in Nature Physics, the researchers have used their device to preserve anti-hydrogen for 16 minutes (aeons in atomic-physics terms).现在,研究人员在自然物理杂志上发表的报告称,他们已经利用设计的装置将反氢子存在时间延续到了16分钟。(在原子物理术语上相当于亿万年)。This gives the anti-atoms plenty of time to settle into their ground state, the most stable condition a particle or atom can attain.这给反原子充分的时间进入能量基态,这是粒子或原子所能获得的最稳定状态。As a result, Dr Hangst and his colleagues can look in a leisurely manner for novel ways that antimatter might differ from the common-or-garden variety.因此,Hangst士及其同事能够寻找新的途径从容地观测反物质可能与普通物质存在的差别。Their first experiment will involve nudging the trapped anti-atoms with microwaves.他们的首次实验将包含用微波对捕获的反原子进行微移。If the frequency of these microwaves is just right, they will flip an anti-atoms spin.如果这些微波的频率恰好正确,它们将会反转反原子的旋转方向。That reverses the polarity of the atoms magnetic field and ejects it from the trap.于是原子的磁场极性被改变并将原子抛出电磁阱。The frequency needed to do this can then be compared with that which flips the spin of an ordinary hydrogen atom. If the two turn out to be different, it will point towards the nature of the mysterious cosmic asymmetry.实验所需的频率随后将与反转普通氢原子旋转方向所用频率进行对比,如果两种频率数值不同,将为神秘宇宙的非对称性提供据。Besides being of huge interest (it would, after all, be a legitimate answer to the question ;why are we here?;), such a result would also have a pleasing symmetry of its own.这个研究结果除了非常有趣(它最终会为;人类为什么会存在?;这个问题提供合乎逻辑的),该结果的本身也有令人欣喜的对称性。The original discovery of antimatter was a nice example of theory predicting an undiscovered fact. This would be a fact that repaid the compliment by predicting an undiscovered theory.当初发现反物质是理论预测未知事实的一个范例,而现在根据反物质的研究发现不对称性的事实则是事实预测了未知理论。 /201212/212909昆明哪里有牙科门诊昆明市东川区口腔医院A debate team from Wenzao Ursuline College of Languages in the southern port city of Kaohsiung won the ;English as a foreign language; (EFL) category of the Northeast Asian Open 2008 Debating Championship earlier this month.文藻外语学院位于台湾省南部港都高雄市,学院辩论队在2008年东北亚英语辩论公开赛上夺冠。Executives of the college introduced the members of the debate team at a news conference held on the campus of Wenzao.文藻学院举行了新闻发布会,会上学院高管介绍了辩论队的成员。The debate team consisted of three students: Yen Tzu-chien, a senior in the Department of Foreign Language Instruction; Fang Chia-hsuan, a junior in the Department of Translation and Interpretation; and Pan Chun-ting, a fifth-year student in the Department of French in the junior college division.队伍包括三名学生:文藻外语学院英文学系所一年级学生陈子珺,文藻外语学院翻译学系二年级学生萧琬融,以及文藻外语学院法文学系五年级学生潘俊廷。They defeated more than 100 debaters from other countries and territories, including Japan, South Korea, and Hong Kong, to capture the championship in the EFL category of the competition, held at Kyoto Seika University.他们打败了来自其他国家地区的100多名辩手,这些国家包括日本,韩国,香港。这次辩论赛在京都精华大学举行,文藻学院辩手获得英语辩论赛冠军。In the final competition, the Wenzao team defeated the team from Seikei University in Tokyo, with a 3-0 decision by the judges.在决赛上,文藻辩论队以3比0的成绩打败来自京都精华大学的辩论队。In addition to winning the overall championship, team member Yen, together with a contestant from Japan and another contestant from South Korea, placed first among the top 10 speakers in the EFL category.除了赢得总冠军之外,文藻辩论队成员陈子珺与来自日本和韩国的其他两名辩手被评为十佳英语辩手。The Wenzao Debate Societys leader, Hsiao Yi-chiao-a third-year student in the five-year junior college-was invited to serve as a judge for the competition.文藻辩论社的队长-一名5年制专科学院的三年级学生被邀请作为辩论赛的评委。201205/184810香格里拉市德钦县维西傈僳族县牙科医院

昆明龅牙手术多少钱昆明柏德口腔美容医院根管治疗氟斑牙怎么样好吗Long Live Us人类万岁About a century ago, the average life-span for Americans was about 50 years. Today, the typical American lives for around seventy-eight years.约一个世纪以前,美国的人均寿命是50岁左右。如今,美国一般都能活到78岁左右。According to a German aging study, the maximum life span in industrialized countries has increased by two years every decade since the mid 19th century. What accounts for such increased longevity?德国一项关于寿命的研究指出,19世纪中叶以来工业化国家人口的最高寿命增长迅速——每十年人们的最高寿命就会增长两岁。是什么让人们的寿命增长的如此之快呢?Between 1900 and 1950, inventions such as refrigeration and sewage treatment meant that young people were able to survive longer. Moreover, medical breakthroughs helped contain diseases such as polio, which killed many children. These advances helped increase the average life span.1900年至1950年期间,制冷技术及污水处理的发明便意味着年轻的一代能活得更久。再者,医疗水平的重大突破对一些疾病起到了很好的控制作用,例如夺去许多儿童生命的小儿麻痹症。社会的这些进步都有助于提高人类的平均年龄。Medical discoveries after World War II tended to benefit older people. Treatments for heart disease, for example, have allowed the elderly to live longer on average. So does this mean that future medical breakthroughs will result in even longer average life spans, or have we reached our limit? Scientists disagree.二战后的科学研究都倾向于“造福”老年群体。就拿对心脏病的治疗来说,就大大提高了老年人的平均寿命。那我们是不是就可以由此推出——日后的医学突破将会使人类的平均寿命再得到延长,或是,人类已经达到了生命的极限?科学家对此持否定看法。Some argue that if science is one day able to eradicate disease and old-age infirmity, there will be virtually no limit on how long humans can live. Some even predict that by the year 2150, the average life span will have increased to around 120 years.有人认为,如果科学能够消除一切疾病以及年老体衰,那么人类的寿命就没有了限度。更有甚者,有人预测到2150年,人类的平均寿命将会达到惊人的120岁。Other life-expectancy researchers find that scenario highly unlikely. Our bodies cells can keep reproducing for only so long before they peter out. Only when science finds a way to keep our cells dividing longer will we see another significant leap in life expectancy.其他的寿命研究人员认为这样的假设是不可能的。人体细胞只能在细胞数量逐渐减少前不断进行复制。除非科学家们找到方法延长细胞分裂时间,人类的平均寿命才可能再有一次突飞猛进。Still, with plenty of exercise and a healthy diet, those so inclined can always hope that theyll live long enough to break the record held by Jeanne Louise Calment of France, who lived to be 122.当然,那些赞成此种观点的人也可以怀抱这样的一份希望——坚持锻炼,养成健康的饮食习惯,打破法国Jeanne Louise Calment老人122岁的长寿记录。 /201211/211588In latitudes that have four seasons, springtime means the rebirth of nature. Flowers bloom and trees grow new leaves. So it is easy to imagine this idiom, which indicates renewal, as having a springtime association. After all, isnt ;trying to improve ones behavior or attitude; (which is the meaning of this idiom) similar to a tree growing new leaves?高纬度地区有四季,春季意味着万物的复苏。花朵绽放,树也长出新叶。因此很容易就想起那个用来形容新生、与春天有一定的联系的成语。毕竟“试图改进某人的行为或者态度”(指成语的意思)与树木长出新叶相似。It turns out that is only part of the story. The reference to ;turning over a new leaf; actually refers to a blank page in a book, such as a diary in which you write the story of your life. Long ago, book pages were called ;leaves; because pages are flat and broad like the leaves of trees. A ;new leaf; would be an empty page, not written on yet. ;Turning it over; means that a fresh start is possible. An empty page indicates unlimited possibilities.事实明这只是其中的一层意思。“turning over a new leaf”中的“leaf”实际上是指一本书的空白页,比如说记录生活点滴的日记本。很久以前,人们称书页为“leaves”,因为书页就像树叶一样平展。“new leaf”则指新的一页,还没有被写的一页。;Turning it over;指全新的开始。空白页则表示有无限的可能性。原文译文属!201212/216983昆明去哪里洗牙昆明市柏德医院直丝弓自锁隐形矫正多少钱

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