智科眼

请选择以下任意方式登录

已有帐号?

验证码登录

微信登录

忘记密码
未收到验证码?
注册

微信注册

智科眼: 双语看懂新科研
地球科学 1634
Using(利用) rare(稀有) oxygen(氧分) molecules(分子) trapped() in(in) air bubbles(气泡) in(in) old() ice() and() snow(),(,) U(U) .(.) S.(S.) and() French(法国) scientists(科学家) have(have) answered(回答) a(一个) long(长期)-()standing(存在) question(问题):(:) How(How) much() have(have) "(")bad(bad)"(") ozone(臭氧) levels(水平) increased(增加) since() the start(开始) of(of) the Industrial(工业) Revolution(革命)?(?)
"We've("We've) been(been) able(能够) to(to) track(追踪) how(how) much() ozone(臭氧) there() was() in(in) the ancient(古代) atmosphere(大气),"(,") said() Rice(赖斯) University(大学) geochemist(地球化学家) Laurence(Laurence) Yeung(),(,) the lead(lead) author(作者) of(of) a(一项) study(研究) published(发表) online(在线) today(今天) in(in) Nature(自然).(.) "(")This(这一) hasn()'t('t) been(been) done(done) before(以前),(,) and() it's(it's) remarkable(非常值) that(that) we(我们) can(可以) do() it() at(at) all(all)."(.")
Researchers(研究人员) used(使用) the new() data(数据) in(in) combination(结合) with(with) state(状态)-of-(-of-)the-()art(art) atmospheric chemistry(大气化学) models(模型) to(to) establish(确定) that(that) ozone(臭氧) levels(水平) in(in) the lower atmosphere(低层大气),(,) or() troposphere(对流层),(,) have(have) increased(上升) by(by) an(an) upper limit(上限) of(of) 40%(40%) since() 1850.(1850.)
"(")These(这些) results(结果) show(表明) that(that) today(今天)'s('s) best(最好) models(模型) simulate(模拟) ancient(古老) tropospheric(对流层) ozone(臭氧) levels(水平) well(很好地),"(,") said() Yeung().(.) "(")That(That) bolsters() our(我们) confidence(信心) in(in) their(它们) ability(能力) to(to) predict(预测) how(如何) tropospheric(对流层) ozone(臭氧) levels(水平) will(will) change(变化) in(in) the future(未来)."(.")
The Rice(赖斯)-()led(领导) research(科学研究) team(团队) includes(包括) investigators(调查) from(from) the University(大学) of(of) Rochester(罗切斯特) in(in) New() York(纽约),(,) the French(法国) National(国家) Center(中心) for(for) Scientific Research(科学研究)'s('s) (CNRS)((CNRS)) Institute() of(of) Environmental(环境) Geosciences(地球) at(at) Universit(Universit)é(é) Grenoble(格勒诺布尔) Alpes(Alpes) (UGA),((UGA),) CNRS's(CNRS's) Grenoble(格勒诺布尔) Images(图像) Speech(语音) Signal(信号) and() Control Laboratory(控制实验室) at(at) UGA(UGA) and() the French(法国) Climate(气候) and() Environmental(环境) Sciences(科学研究) Laboratory(实验室) of(of) both(both) CNRS(CNRS) and() the French(法国) Alternative(替代) Energies(能源) and() Atomic Energy Commission(原子能委员会) (CEA)((CEA)) at(at) the Universit(Universit)é(é) Versailles(凡尔赛)-St(-St) Quentin(Quentin).(.)
"(")These(这些) measurements(测量) constrain(限制) the amount() of(of) warming(变暖) caused(引起) by(by) anthropogenic(人为) ozone(臭氧),"(,") Yeung(Yeung) said().(.) For example(例如),(,) he() said() the most() recent() report(报告) from(from) the Intergovernmental(政府间) Panel(专门) on(on) Climate Change(气候变化) (IPCC)((IPCC)) estimated(估计) that() ozone(臭氧) in(in) Earth(地球)'s('s) lower atmosphere(低层大气) today(今天) is() contributing(贡献) 0.4(0.4) watts() per() square meter(平方米) of(of) radiative(辐射) forcing(强度) to(to) the planet(地球)'s('s) climate(气候),(,) but() the margin of error(误差范围) for(for) that(that) prediction(预测) was(was) 50%,(50%,) or() 0.2(0.2) watts() per() square meter(平方米).(.)
"(")That(That)'s('s) a(一个) really(非常) big() error(错误) bar(),"(,") Yeung() said().(.) "(")Having() better(更好) preindustrial(工业化前) ozone(臭氧) estimates(估计值) can(可以) significantly(显着) reduce(减少) those(这些) uncertainties(不确定性).(.)
"It's("It's) like() guessing(猜测) how(how) heavy() your(你的) suitcase(行李箱) is(is) when(when) there()'s('s) a(a) fee(收取) for(for) bags() over(超过) 50(50) pounds(),"(,") he() said().(.) "(")With(With) the old() error(错误) bars(),(,) you()'d('d) be(be) saying(),(,) 'I('I) think(认为) my(我的) bag(行李) is(is) between(between) 20(20) and() 60(60) pounds().'(.') That(That)'s('s) not() good() enough() if(如果) you() can()'t('t) afford() to(to) pay() the penalty(罚款)."(.")
Ozone(臭氧) is() a(一种) molecule(分子) that(that) contains(含有) three(三个) oxygen atoms(氧原子).(.) Produced(产生) in(in) chemical reactions(化学反应) involving(涉及) sunlight(太阳光),(,) it() is() highly() reactive(反应性),(,) in(in) part(部分) because() of(of) its() tendency(倾向) to(to) give(放弃) up(up) one(一个) of(of) its(它的) atoms(原子) to(to) form(形成) a(a) more() stable(稳定) oxygen(氧分) molecule(分子).(.) The majority(大部分) of(of) Earth(地球)'s('s) ozone(臭氧) is(is) in(in) the stratosphere(平流层),(,) which(which) is(is) more than(以上) five(5) miles(英里) above(以上) the planet(地球)'s('s) surface(表面).(.) Stratospheric(平流层) ozone(臭氧) is() sometimes(有时) called(称为) "(")good()"(") ozone(臭氧) because(因为) it() blocks(阻挡) most(most) of(of) the sun(太阳)'s('s) ultraviolet(紫外线) radiation(辐射),(,) and() is(is) thus(因此) essential(至关重要) for(for) life(生命) on(on) Earth(地球).(.)
The rest(其余) of(of) Earth(地球)'s('s) ozone(臭氧) lies(位于) in(in) the troposphere(对流层),(,) closer(靠近) to(to) the surface(地表).(.) Here(这里),(,) ozone(臭氧)'s('s) reactivity(反应性) can(可能) be(be) harmful(有害) to(to) plants(植物),(,) animals(动物) and() people().(.) That(That)'s('s) why(为什么) tropospheric(对流层) ozone(臭氧) is() sometimes(有时) called(称为) "(")bad()"(") ozone(臭氧).(.) For example(例如),(,) ozone(臭氧) is() a(a) primary(主要) component(成分) of(of) urban(城市) smog(烟雾),(,) which(which) forms(形成) near(接近) ground(地面) level(水平) in(in) sunlit(阳光照射)-()driven(驱动) reactions(反应) between(between) oxygen(氧气) and() pollutants(污染物) from(from) motor vehicle(机动车) exhaust(尾气).(.) The Environmental Protection Agency(环境保护局) considers(认为) exposure(暴露) to(to) ozone(臭氧) levels(水平) greater(更大) than(than) 70(70) parts(分之) per() billion(十亿) for(for) eight() hours(小时) or() longer(更长) to(to) be(be) unhealthy(不健康).(.)
"(")The thing(事情) about(关于) ozone(臭氧) is() that(that) scientists(科学家们) have(have) only(only) been(been) studying(研究) it() in(in) detail(详细) for(for) a(a) few(few) decades(几十年),"(,") said() Yeung(Yeung),(,) an(an) assistant(助理) professor(教授) of(of) Earth(地球),(,) environmental(环境) and() planetary(行星) sciences(科学).(.) "We("We) didn(didn)'t('t) know(知道) why(为什么) ozone(臭氧) was(was) so(如此) abundant(丰富) in(in) air pollution(空气污染) until(直到) the 1970s.(1970s.) That()'s('s) when(when) we(我们) started(开始) to(to) recognize(认识) how(如何) air pollution(空气污染) was(was) changing(改变) atmospheric chemistry(大气化学).(.) Cars(汽车) were(were) driving(推动) up(up) ground(地面)-()level(水平) ozone(臭氧)."(.")
While(虽然) the earliest(最早) measurements(测量) of(of) tropospheric(对流层) ozone(臭氧) date(数据) to(to) the late(后期) 19th(19th) century(世纪),(,) Yeung() said() those(这些) data(数据) conflict(冲突) with(with) the best(最佳) estimates(估计) from(from) today(当今)'s('s) state(状态)-of-(-of-)the-()art(art) atmospheric chemistry(大气化学) models(模型).(.)
"(")Most(大多数) of(of) those(那些) older() data(数据) are(are) from(from) starch-paper(淀粉纸) tests(测试) where(where) the paper() changes(改变) colors(颜色) after(after) reacting(反应) with(with) ozone(臭氧),"(,") he() said().(.) "(")The tests(测试) are() not() the most() reliable(可靠)()the color(颜色) change(变化) depends(取决于) on(on) relative humidity(相对湿度),(,) for example(例如)()but() they(他们) suggest(认为),(,) nevertheless(尽管如此),(,) that(that) ground(地面)-()level(水平) ozone(臭氧) could(可能) have(have) increased(增加) up(up) to(to) 300%(300%) over(over) the past(过去) century(世纪).(.) In(In) contrast(),(,) today(今天)'s('s) best(最好) computer models(计算机模型) suggest(显示) a(a) more() moderate(温和) increase(增长) of(of) 25-50%.(25-50%.) That(That)'s('s) a(一个) huge(巨大) difference(差异).(.)
"(")There(那里)'s('s) just(just) no(没有) other(其他) data(数据) out(out) there(there),(,) so(因此) it's(it's) hard() to(to) know(知道) which(哪个) is() right(正确),(,) or(或者) if() both(两者) are() right(正确) and() those() particular(特定) measurements(测量) are() not() a(a) good(良好) benchmark(基准) for(for) the whole(整个) troposphere(对流层),"(,") Yeung(Yeung) said().(.) "(")The community(社区) has(has) struggled(努力) with(with) this(这个) question(问题) for(for) a(a) long(长期) time(time).(.) We(我们) wanted(希望) to(to) find(找到) new() data(数据) that(that) could(可以) make(make) headway(取得) on(on) this(这个) unsolved(未解) problem(问题)."(.")
Finding() new() data(数据),(,) however(但是),(,) is(is) not() straightforward(简单).(.) "(")Ozone(臭氧) is(is) too(过于) reactive(活跃),(,) by(by) itself(本身),(,) to(to) be(be) preserved(保存) in(in) ice() or(or) snow(),"(,") he() said().(.) "So,("So,) we(我们) look(寻找) for(for) ozone(臭氧)'s('s) wake(尾迹),(,) the traces(痕迹) it() leaves(留下) behind(behind) in(in) oxygen(氧分) molecules(分子).(.)
"(")When(When) the sun(太阳) is() shining(),(,) ozone(臭氧) and() oxygen(氧气) molecules(分子) are(are) constantly(不断) being(being) made(制造) and() broken() in(in) the atmosphere(大气层) by(by) the same(同样) chemistry(化学),"(,") Yeung(Yeung) said().(.) "(")Our(我们) work(工作) over(over) the past(过去) several() years() has() found(找到) a(一种) naturally(天然) occurring(存在) '(')tag(标记)'(') for(for) that(that) chemistry(化学):(:) the number(数量) of(of) rare() isotopes(同位素) that(that) are(are) clumped(丛生的) together(一起)."(.")
Yeung(Yeung)'s('s) lab(实验室) specializes(专门) in(in) both(both) measuring(测量) and() explaining(解释) the occurrence(发生) of(of) these(这些) clumped(丛生) isotopes(同位素) in(in) the atmosphere(大气).(.) They(它们) are() molecules(分子) that() have(具有) the usual(常见) number(子数) of(of) atoms(原子)()two(两个) for(for) molecular(分子) oxygen()()but(但是) they(它们) have(具有) rare(稀有) isotopes(同位素) of(of) those(那些) atoms(原子) substituted(取代) in(in) place(发生) of(of) the common() ones().(.) For example(例如),(,) more than(超过) 99.5%(99.5%) of(of) all(all) oxygen atoms(氧原子) in(in) nature(自然界) have(具有) eight(8个) protons(质子) and() eight(8个) neutrons(中子),(,) for(for) a(a) total() atomic mass number(原子质量数) of(of) 16(16) .(.) Only(只有) two(两个) of(of) every() 1,000(1,000) oxygen atoms(氧原子) are() the heavier(较重) isotope(同位素) oxygen()-18,(-18,) which(which) contains(含有) two(两个) additional(额外) neutrons(中子).(.) A(A) pair(一对) of(of) these(这些) oxygen()-18(-18) atoms(原子) is(is) called(称为) an(an) isotope(同位素) clump(团块).(.)
The vast(广阔) majority(绝大多数) of(of) oxygen(氧分) molecules(分子) in(in) any(任何) air(空气) sample(样本) will(will) contain(含有) two(两个) oxygen()-16s.(-16s.) A(一种) few(few) rare(罕见) exceptions(例外) will() contain(包含) one(one) of(of) the rare(罕见) oxygen()-18(-18) atoms(原子),(,) and() rarer(罕见) still(仍然) will(will) be(be) the pairs() of(of) oxygen()-18s.(-18s.)
Yeung(Yeung)'s('s) lab(实验室) is() one(之一) of(of) the few(few) in(in) the world(世界) that(that) can(可以) measure(测量) exactly(究竟) how many(多少) of(of) these(这些) oxygen()-18(-18) pairs() are(are) in(in) a(a) given(给定) sample(样本) of(of) air(空气).(.) He() said() these(这些) isotope(同位素) clumps(团块) in(in) molecular(分子) oxygen(氧气) vary(不同) in(in) abundance(大量) depending(取决于) on(on) where(where) ozone(臭氧) and() oxygen() chemistry(化学) occurs(发生).(.) Because(由于) the lower(较低) stratosphere(平流层) is(is) very(非常) cold(),(,) the odds(可能性) that(that) an(an) oxygen()-18(-18) pair() will(will) form(形成) from(from) ozone(臭氧)/(/)oxygen() chemistry(化学) increase(增加) slightly(略有) and() predictably(可预) compared(相比) to(to) the same(相同) reaction(反应) in(in) the troposphere(对流层).(.) In(In) the troposphere(对流层),(,) where(where) it() is(is) warmer(),(,) ozone(臭氧)/(/)oxygen(氧气) chemistry(化学) yields(产生) slightly() fewer() oxygen(氧气)-18(-18) pairs().(.)
With(With) the onset(开始) of(of) industrialization(工业化) and() the burning(燃烧) of(of) fossil fuels(化石燃料) around(左右) 1850,(1850,) humans(人类) began(开始) adding(添加) more(更多) ozone(臭氧) to(to) the lower atmosphere(低层大气).(.) Yeung(Yeung) and() colleagues(同事) reasoned(推断) that() this() increase(增加) in(in) the proportion(比例) of(of) tropospheric(对流层) ozone(臭氧) should(应该) have(have) left(留下) a(一个) recognizable(可识别) trace(痕迹)—a(—a) decrease(减少) in(in) the number(数量) of(of) oxygen()-18(-18) pairs() in(in) the troposphere(对流层).(.)
Using(使用) ice() cores() and() firn(粒雪) ((()compressed(压缩) snow() that(that) has(has) not(尚未) yet(然而) formed(形成) ice())()) from() Antarctica(南极洲) and() Greenland(格陵兰岛),(,) the researchers(研究人员) constructed(建立) a(a) record(记录) of(of) oxygen(氧气)-18(-18) pairs() in(in) molecular(分子) oxygen() from(from) preindustrial(工业) times(时代) to(to) the present(现在).(.) The evidence(证据) confirmed(证实了) both(both) the increase(增加) in(in) tropospheric(对流层) ozone(臭氧) and() the magnitude(幅度) of(of) the

新闻订阅

  • 科学
  • 技术
  • 医学

新闻分享