2011职称英语阅读理解-必考题型

一、职称英语阅读理解文章（理工类）译文(参加理工A/B/C级考试需要掌握文章)    3 第一篇    福特放弃电动汽车    3 Ford Abandons Electric Vehicles    3 第二篇    能发电的背包    4 Electric Backpack    5 第三篇    公民科学家    5 Citizen Scientists    6 第四篇    汽车技术    6 Motoring Technology    7 第五篇    深夜喝咖啡    7 Late-night Drinking    8 第六篇    北极冰山融化    8 Arctic Melt    9 第七篇    用糖为手机发电    9 Sugar Power for Cell Phones    10 第八篇    引人注目的埃菲尔铁塔    11 Eiffel Is an Eyeful    11 第九篇    埃及饱受饥饿折磨    12 Egypt felled by famine    12 第十篇    年轻雌猩猩学习优于她们的弟兄    13 Young Female Chimps Outlearn Their Brothers    13 第十一篇    申请个人域名的网上费用    14 The Net Cost of Making a Name for Yourself    14 第十二篇    纳佛罗里达遭受冷气团袭击    15 Florida Hit by Cold Air Mass    15 第十三篇    隐形环    16 Invisibility Ring    16 第十四篇    日本用来监视醉酒司机的新型概念车    17 Japanese Car Keeps Watch for Drunk Drivers    17 第十五篇    肋生双翅机器人学飞行    18 Winged Robot Learns to Fly    18 第十六篇    日本人的地心旅行    19 Japanese Drilling into Core of Earth    19 第十七篇    地球防晒霜    20 A Sunshade for the Planet    20 第十八篇    石油匮乏    21 Thirst for Oil    22 第十九篇    延长人类寿命    22 Prolonging Human Life    23 第二十篇    深海探索器    23 Explorer of the Extreme Deep    24 第二十一篇    植物，沼气的又一来源    24 Plant Gas    25 第二十二篇    雪  花    25 Snowflakes    26 第二十三篇    风力发电？轻而易举    27 Powering a City? It’s a Breeze    27 第二十四篇    地下煤引发即将来临的灾难    28 Underground Coal Fires a Looming Catastrophe    28 第二十五篇    为了活着吃饭    29 Eat to Live    29 第二十六篇    男女飞行员引起飞行事故的差异    30 Male and Female Pilots Cause Accidents Differently    31 第二十七篇    分散注意力驾驶    31 Driven to Distraction    32 第二十八篇    睡眠促使记忆归档存储    33 Sleep Lets Brain File Memories    33 第二十九篇    古怪食物    34 Food Fright    35 二、职称英语阅读理解文章译文(参加理工A、B级考试需要掌握文章)    35 第三十篇    数码王国    35 Digital Realm    36 第三十一篇    卡特里娜飓风    37 Hurricane Katrina    37 第三十二篇    读心机    38 Mind-reading Machine    38 第三十三篇    专家呼吁局部和区域控制放射性废物地点    39 Experts Call for Local and Regional Control of Sites for Radioactive Waste    39 第三十四篇    不要轻易相信象粪    40 Don’t Count on Dung    40 第三十五篇    植物效能    41 Putting Plants to Work    42 第三十六篇    听觉仪器提供早期山崩预警    43 Listening Device Provides Landslide Early Warning    43 第三十七篇    不要在就餐时间以外饮酒有了新含义    44 “Don’t Drink Alone” Gets New Meaning    44 第三十八篇    蚂蚁的死亡    45 Night of the Living Ants    46 第三十九篇    克隆农场    47 Clone Farm    47 第四十篇    污染云团在太平洋两岸均被测量    48 Air Pollution Cloud Measured on Both Sides of Pacific    48 三、职称英语阅读理解文章译文(参加理工A级考试需要掌握文章)    49 第四十一篇    全球变暖“缺油”    49 Too Little for Global Warming    50 第四十二篇    可再生能源    50 Renewable Energy Sources    51 第四十三篇    天气预报的方法    52 Forecasting Methods    52 第四十四篇    捍卫进化论仍必要    53 Defending the Theory of Evolution Still Seems Needed    53 第四十五篇    卡拉奇的干渴    54 Thirsty in Karachi    55 第四十六篇    宇宙中的第一颗星是怎样形成的    56 How the First Stars in the Universe Came into Existence    56 第四十七篇    倾听鸟鸣    57 Listening to Birdsong    58 第四十八篇    “隐种”可能令人惊叹地普遍存在    59 "Hidden" Species May Be Surprisingly Common    59 第四十九篇    美国科学家确认火星上有水    60 U.S. Scientists Confirm Water on Mars    61 第五十篇    手机增加交通行人死亡    62 Cell Phones Increase Traffic, Pedestrian Fatalities    62 一、职称英语阅读理解文章（理工类）译文(参加综合A、B、C级考试需要掌握文章) 第一篇 福特放弃电动汽车 分析人士评论，福特汽车公司放弃电动汽车的举动有力地证明了这种技术是行不通的。 通用汽车和日本本田公司早于1999 年就停止了电池动力汽车的生产，转而开发燃料电池和电池内燃混合机，这对消费者更吸引力。福特宣布它现在也要做同样的尝试。 3年前，福特推出名为Think City 的双排座汽车和Think 或Think Neighbor 系列高尔夫车。但由于需求不足，截至2002年仅生产了1 000 辆汽车，售出1 700辆高尔夫车。 “关键是我们认为电动车不能代表大众市场环保交通的未来”，福特欧洲区的Tim Holmes 于周五说，“我们感觉自己对电力车的两倍多。”日本丰田产的RAV4EV 系列电动车在美国的售价达42 000 美元，而同一系列的汽油动力车仅售17 000 美元。 丰田和日产汽车公司是现在仅存的两在电动车制造商。 “应该说电池动力车已经获得了充分的机会。福特现已转向电池内燃混合机开发项目，我们应据此评价他们的发展。”Roger Higman, 英国Friends of the Earth组织的一位高级交通运动代表这样对《环保新闻》评论说。 日本本田和丰田公司推出的混合机汽车在过去几年取得了良好的销售业绩。混合动力车比汽油机车运行里程更长，电池又可自行充电。福特表示，他们认为这样的机车有助于达到美国新制订的车辆排放规定。 不过这些规定究竟允许怎样的排放现在还不十分清楚。六月份通用和戴姆勒克莱斯勒公司赢得一项法庭裁决，可推迟两年执行一项加州法令，该法令要求汽车生产商在2003 年前向该州提供10万辆零排放和其他低排放汽车。制造商希望修改此法令，允许他们生产现多低排放而不是零排放的汽车。 Ford Abandons Electric Vehicles The Ford motor company’s abandonment of electric cars effectively signals the end of the road for the technology, analysts say. General Motors and Honda ceased production of battery-powered cars in 1999, to focus on fuel cell and hybrid electric gasoline engines, which are more attractive to the consumer. Ford has now announced it will do the same. Three years ago, the company introduced the Think City two-seater car and a golf cart called the THINK, or Think neighbor. It hoped to sell 5,000 cars each year and 10,000 carts. But a lack of demand means only about 1,000 of the cars have been produced, and less than 1,700 carts have been sold so far in 2002. “The bottom line is we don’t believe that this is the future of environment transport for the mass market,” Tim Holmes of Ford Europe said on Friday. “We feel we have given electric our best shot.” The Think City has a range of only about 53 miles and up to a six-hour battery recharge time General Motor’s EVI electric vehicle also had a limited range, of about 100 miles. The very expensive batteries also mean electric cars cost much more than petrol-powered alternatives. An electric Toyota RAV4 EV vehicle costs over $42,000 in the US, compared with just $17,000 for the petrol version. Toyota and Nissan are now the only major auto manufacturers to produce electric vehicles. “There is a feeling that battery electric has been given its chance. Ford now has to move on with its hybrid program, and that is what we will be judging them on,” Roger Higman, a senior transport campaigner at UK Friends of the Earth, told the Environment News Service. Hybrid cars introduced by Toyota and Honda in the past few years have sold well. Hybrid engines offer greater mileage than petrol-only engines, and the batteries recharge themselves. Ford says it thinks such vehicles will help it meet planned new guidelines on vehicle emissions in the US. However, it is not yet clear exactly what those guidelines will permit. In June, General Motors and Daimler Chrysler won a court injunction, delaying by two years Californian legislation requiring car-makers to offer 100,000 zero-emission and other low-emission vehicles in the state by 2003. Car manufactures hope the legislation will be rewritten to allow for more low-emission, rather than zero-emission, vehicles. 第二篇 能发电的背包 背包是很方便的工具，可以装书，带午餐，带换洗的衣服，双手还可以解放出来做别的事。将来有一天，如果你不介意背上重荷，你的背包或许能为你的MP3播放器提供电能，保证你手机的电量，甚至可以在你回家的路上为你照明。 来自费城宾夕法尼亚大学和麻省伍兹霍尔海洋生物学实验室的LawrenceC Rome和他的同事们发明了一种能利用背包者行走时产生的能量发电的背包。在军事行动、搜救实施、科学研究的实地研究中，人们越来越多地依赖手机、全球定位系统接收器、夜视镜及其他用电池供电的装置来克服困难进行工作。在9月9日的《科学》杂志上，Lawrencee Rome和他的同事们指出，背包的发电特点有可能大大减轻现在的背包者因为装多个备用电池而带来的重荷。 背包的发电能力依赖于把布包从它的金属框架上撑起来的许多弹簧。金属框架挨着背包者的背，人走动时整个包上下移动，一个转换装置把包的垂直运动变成一台发电机的转动，这样就产出多达7．4瓦的电能。 测试显示背新型背包的人为了适应包的摆动会改变步态，而这样比他们用一般背包背东西既省劲又舒服，这是出入意料的。由于有这样令人吃惊的优点，Rome对能发电的新型背包和不能发电的新型背包都进行商业化开发。 士兵、科学家、登山者及紧急救援工作者通常背负沉重的背包，新型背包对他们尤其有用。对其他行业的人来说，能发电的背包使他们边走路边玩视频游戏、边看电视、边听音乐成为可能。能发电的背包至今还未上市，不过假如你以后终于买到了一个，一定记着过马路时要两边看看! Electric Backpack Backpacks are convenient. They can hold your books, your lunch, and a change of clothes, leaving your hands free to do other things. Someday, if you don't mind carrying a heavy load, your backpacks might also power your MP31 player, keep your cell phone running, and maybe even light your way home. Lawrence C. Rome and his colleagues from the University of Pennsylvania in Philadelphia2 and the Marine Biological Laboratory in Woods Hole3, Mass. 4, have invented a backpack that makes electricity from energy produced while its wearer walks. In military actions, search-and-rescue operations, and scientific field studies, people rely increasingly on cell phones, global positioning system (GPS)5 receivers, night-vision goggles, and other battery-powered devices to get around and do their work.  The backpack's electricity-generating feature could dramatically reduce the amount of a wearer's load now devoted to spare batteries, report Rome and his colleagues in the Sept. 9 Science6. The backpack's electricity-crew, ring powers depend on springs used to hang a cloth pack from its metal frame. The frame sits against the wearer’s back, and the whole pack moves up and down as the person walks. A gear mechanism converts vertical movements of the pack to rotary motions of an electrical generator, producing up to 7.4 watts. Unexpectedly, tests showed that wearers of the new backpack alter their gaits in response to the pack's oscillations, so that they carry loads more comfortably and with less effort than they do ordinary backpacks. Because of that surprising advantage, Rome plans to commercialize both electric and non-electric versions of the backpack. The backpack could be especially useful for soldiers, scientists, mountaineers, and emergency workers who typically carry heavy backpacks. For the rest of us, power-generating backpacks could make it possible to walk, play video games, watch TV, and listen to music, all at the same time. Electricity-generating packs aren't on the market yet, but if you do get one eventually, just make sure to look Both ways before crossing the street! 第三篇 公民科学家 理解大自然对气候变化有怎样的反应需要监视世界各个角落的关键生命周期事件——花开、叶子的出现、第一只青蛙叫出春天的到来。但是生态学家不可能去到世界的各个角落，所以他们向非科学家求助，这些非科学家有时也被称作公民科学家。 气象科学家不可能足迹遍及天下。因为在世界上有如此多的地方，没有足够的科学家来观察它们。所以他们请求你来帮助观察全世界气候变化的迹象。公民科学家运动鼓励普通人根据自己的兴趣来观察某一个特定的方面——鸟儿、树木、花开等等——并把他们的观察结果发送到一个巨大的数据库来供专业科学家研究。这有助于数量有限的科学家得到如果只靠他们自己根本收集不到的巨大数据。就像公民记者帮助报道传统新闻报道方式所忽略的小型社区的相关信息一样，公民科学家也对他们所居住的环境很熟悉。所需要的就是每天或每周留出几分钟来搜集数据并发送过来。 一群科学家和教育家在去年发起了一个叫做纽约国家物候学的组织。”物候学”就是科学家们所说的在自然中研究每个事件的时间。 其中一个小组的首要尝试就是依靠科学家和非科学家来收集关于每年植物开花和长叶子的数据。这一项目叫做花季追踪计划，它收集遍布美国的各种各样的植物生长周期的数据。参与这一项目的人们——这一计划对所有人开放——把他们的观察记录在花季追踪计划网站上。 “人们不需要是植物学家——他们仅仅需要环视四周看看周围有什么。”Jennifer Schwartz说，她是这项计划的教育顾问。”通过收集数据，我们就能够估算出气候变化对植物和生物群落会有怎样的影响。” Citizen Scientists Understanding how nature responds to climate change will require monitoring key life cycle event—flowering, the appearance of leaves, the first frog calls of the spring—all around the world. But ecologists can’t be everywhere so they’re turning to non-scientists, sometimes called citizen scientists, for help. Climate scientists are not present everywhere. Because there are so many places in the world and not enough scientists to observe all of them, they’re asking for your help in observing signs of climate change across the world. The citizen scientist movement encourages ordinary people to observe a very specific research interest — birds, trees, flowers budding, etc. — and send their observations to a giant database to be observed by professional scientists. This helps a small number of scientists track a large amount of data that they would never be able to gather on their own. Much like citizen journalists helping large publications cover a hyper-local beat, citizen scientists are ready for the conditions where they live. All that’s needed to become one is a few minutes each day or each week to gather data and send it in. A group of scientists and educators launched an organization last year called the National Phenology Network. “Phenology” is what scientists call the study of the timing of events in nature. One of the group’s first efforts relies on scientists and non-scientists alike to collect data about plant flowering and leafing every year. The program, called Project BudBurst, collects life cycle data on a variety of common plants from across the United States. People participating in the project—which is open to everyone—record their observations on the Project BudBurst website. “People don’t have to be plant experts -they just have to look around and see what’s in their neighborhood,” says Jennifer Schwartz, an education consultant with the project. “ As we collect this data, we’ll be able to make an estimate of how plants and communities of plants and animals will respond as the climate changes. ” 第四篇 汽车技术 每年，全世界有120万起路面交通死亡事故，以及五千万起路面交通伤残事故。为降低车祸发生率，现在有很多研究将注意力放在行车安全和开发新型燃料上。而有些关于电动机车和生物燃料的研究旨在达到更快的速度。 高速驾驶一向是很危险的。一项在机动车安全前沿领域的研究是有关车内数字化辅助设施的。这些设施会确保司机们不会错过重要的路况指示牌或在开车时睡着。通过运 用人工智能软件，这些辅助设施可监控行车过程并确保在关键时刻司机不会被手机或广播干扰注意力。许多车祸是由人为原因造成的而非机械故障。 一些行车安全方面的改进力图改善司机的视野。雷达可对雾中的障碍物定位，而其他的科技手段可透过阻碍你视线的高大车辆看到前方。 对安全带、刹车板控制和车胎的改进也使行车过程变得更／顷畅、安全。人们发现车的颜色与安全有关，令人不会感到惊讶的是，车的大小和形状也与安全有关。 从矿物燃料中提取的汽油的替代物，例如植物油，也是研究中的一个热门区域。取材于氢气的燃料电池燃烧时无污染，并已成为一项重要研究的攻克对象。 但不管燃料箱中盛为何物，你可不想在驾驶座上坐的是一个窃贼。对此，也有很多创新来打击汽车盗窃，其中一些运用了卫星跟踪和远程通讯。当发生车祸时，这些通讯系统也可起作用，自动地呼叫帮助。 交通事故可引发许多交通堵塞。但在一畅通却繁忙的路段上，汽车间也有很多的细微互动，从而导致可能的阻塞。此类阻塞可用数据统计工具来进行分析。被编程的机器人可使交通流动更顺畅，并有朝一日有望成为每个人的私家司机。但最新成果表明这种设想并  非短期内可以实现。 Motoring Technology 1.2 million road deaths worldwide occur each year, plus a further 50 million injuries. To reduce car crash rate, much research now is focused on safety and new fuels － though some electric vehicle and biofuel research aims at going faster. Travelling at speed has always been risky. One cutting edge area of research in motoring safety is the use of digital in-car assistants. They can ensure you don’t miss crucial road signs or fall asleep. The use of artificial intelligence software allows these assistants to monitor your driving and makes sure your phone or radio doesn’t distract you at a vital moment. Most crashes result from human and not mechanical faults. Some safety developments aim to improve your vision. Radar can spot obstacles in fog, while other technology “sees through”high-sided vehicles blocking your view. And improvements to seat belts, pedal controls and tyres are making driving smoother and safer. The colour of a car has been found to be linked with safety, as have, less surprisingly, size and shape. And alternatives to fossil-fuel based petrol, such as plant oils, are a hot area of research. Fuel cells based on hydrogen burn cleanly, and are the subject of a serious research effort. But whatever is in the fuel tank, you don’t want a thief in the driving seat and there have been many innovations, some using satellite tracking and remote communications, to fight against car theft. These communication systems can also come into play if you crash, automatically calling for help. Accidents cause many traffic jams, but there are more subtle interplays between vehicles that can cause jams even on a clear but busy road. Such jams can be analysed using statistical tools. Robotic drivers could be programmed to make traffic flow smoothly and will perhaps one day be everyone’s personal chauffeur, but their latest efforts suggest that won’t be soon. 第五篇 深夜喝咖啡 喜欢喝咖啡的人要小心了。晚上喝一杯快速提神的咖啡对你的睡眠造成严重破坏。并且咖啡因作为一种刺激物会打断褪黑激素的流动。褪黑激素是使人们进入睡眠的神经激素。 褪黑激素的浓度在睡前两小时开始上升。凌晨2点和4点之间达到最高植，然后再次下降。加利福尼亚斯坦福大学的斯坦福睡眠流行病学研究中心的Maurice Ohayon说：“控制我们睡眠是神经激素，它告诉我们的身体什么时候睡觉什么时候醒。”但是以色列的研究者发现含咖啡因咖啡能使人体中这种睡眠激素减半。 特拉维夫大学的塞帕医学中心的Lotan Shilo和一个小组发现六个志愿者在喝了一杯含咖啡因的咖啡后平均每晚睡336分钟，而喝完脱咖啡后平均每晚睡415分钟，他们用半个小时才能睡着——比平常长一倍，而且翻来覆去的时间比平常多一倍。 在试验的第二阶段，研究者每三个小时叫醒志愿者一次，并要他们提供一个尿样。Shilo测量了褪黑激素分解物的浓度。结果表明饮用含咖啡因咖啡的人体内的褪黑激素的浓度是饮用脱咖啡因咖啡的人体内褪黑激素浓度的一半。在《睡眠知学》上发表的一篇中，研究者表示咖啡因阻碍促使褪黑激素产生的酶的形成。 Ohayon建议爱喝咖啡的人午饭后应该换喝脱咖咖啡，因为要排除体内的咖啡因要用好几个小时。 Late-night Drinking Coffee lovers beware. Having a quick “pick-me-up” cup of coffee late in the day will play havoc with your sleep. As well as being a stimulant, caffeine interrupts the flow of melatonin, the brain hormone that sends people into a sleep. Melatonin levels normally start to rise about two hours before bedtime. Levels then peak between 2 a.m. and 4 a.m., before falling again. “It’s the neurohormone that controls our sleep and tells our body when to sleep and when to wake, ” says Maurice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California. But researchers in Israel have found that caffeinated coffee halves the body’s levels of this sleep hormone. Lotan Shilo and a team at the Sapir Medical Center in Tel Aviv University found that six volunteers slept less well after a cup of caffeinated coffee than after drinking the same amount of decaf. On average, subjects slept 336 minutes per night after drinking caffeinated coffee, compared with 415 minutes after decaf. They also took half an hour to drop off4—twice as long as usual—and jigged around in bed twice as much. In the second phase of the experiment, the researchers woke the volunteers every three hours and asked them to give a urine sample. Shilo measured concentrations of a breakdown product of melatonin. The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers. In a paper accepted for publication in Sleep Medicinc, the researchers suggest that caffeine blocks production of the enzyme that drives melatonin production. Because it can take many hours to eliminate caffeine from the body, Ohayon recommends that coffee lovers switch to decaf after lunch. 第六篇 北极冰山融化 地球的北极和南极都以冰冷闻名。但是，去年北冰洋上的冰含量跌到了历史最低点。 正常情况下，每年冬天在北极附近的北冰洋开始结冰，并在夏天缩减。但是多年以来，在夏天结束时冰的含量在下降。 自从1979年以来，每10年在夏季末的冰覆盖量都下降11．4％。在1981到2000年之间，北极冰的厚度下降了22％——变成了1．13米这么薄。 去年，北极的冰雪覆盖达到了最薄的程度。在2007年夏天快结束的时候，冰层已经缩减到只覆盖四百二十万平方公里。这比那年的平均覆盖面积少38％，比两年前最低记录少23％。这个持续的趋势令科学家们万分担忧。 冰雪融化有许多原因，西雅图华盛顿大学的海洋学家张金伦说，有许多原因导致了冰层融化。极不寻常的强风去年刮过大西洋，风把大西洋中部的冰散去，留下大面积的薄冰和没有冰覆盖的海面。 科学家们还怀疑在大西洋上空有比过去越来越少的云层。晴朗的天空使更多的阳光照射大西洋。升高的温度使水和空气都变温暖。在去年大西洋的部分海域，表面温度比平均温度高3．5摄氏度，比历史最高点还高1．5摄氏度。 由于空气和水都变暖，冰从上面和下面都开始融化。在波弗特海的部分海域，阿拉斯加的北部和加拿大的西部，夏天开始时冰的厚度为3．3米，但到了季末仅仅为50厘米。 新的测量表明，情况远远比科学家们仅仅从表面上看到的要严重得多，新罕布什尔州汉诺威市的地球物理学家Donald K．Perovich说。 一些科学家担心北极已经深陷变热的趋势不能恢复。 Arctic Melt Earth’s North and South Poles are famous for being cold and icy. Last year, however, the amount of ice in the Arctic Ocean fell to a record low. Normally, ice builds in Arctic waters around the North Pole each winter and shrinks during the summer. But for many years, the amount of ice left by the end of summer has been declining. Since 1979, each decade has seen an 11.4 percent drop in end-of-summer ice cover. Between 1981 and 2000, ice in the Arctic lost 22 percent of its thickness -becoming 1.13 meters thinner. Last summer, Arctic sea ice reached its skimpiest levels yet. By the end of summer 2007, the ice had shrunk to cover just 4.2 million square kilometers. That’s 38 percent less area than the aver-age cover at that time of year. And it’s a very large 23 percent below the previous record low, which was set just 2 years ago. This continuing trend has scientists concerned. There may be several reasons for the ice melt, says Jinlun Zhang, an oceanographer at the University of Washington in Seattle. Unusually strong winds blew through the Arctic last summer. The winds pushed much of the ice out of the central Arctic, leaving a large area of thin ice and open water. Scientists also suspect that fewer clouds cover the Arctic now than in the past. Clearer skies allow more sunlight to reach the ocean. The extra heat warms both the water and the atmosphere. In parts of the Arctic Ocean last year, surface temperatures were 3.5°Celsius warmer than average and 1.5°C warmer than the previous record high. With both air and water getting warmer, the ice is melting from both above and below. In some parts of the Beaufort Sea, north of Alaska and western Canada, ice that measured 3.3 m thick at the beginning of the summer measured just 50 centimeters by season’s end. The new measurements suggest that melting is far more severe than scientists have seen by just looking at ice cover from above, says Donald K. Perovich, a geophysicist at the U. S. Army Cold Regions Research and Engineering Laboratory in Hanover, N.H. Some scientists fear that the Arctic is stuck in a warming trend from which it may never recover. 第七篇 用糖为手机发电 一种新型燃料细胞通过利用活体细胞中很常见的酶能从糖中生产少量的电。如果这项技术能够成功应用于大批量生产，人们可以与自己的手机分享甜饮料(因为糖可以发电供给手机)。 燃料细胞中的化学反应能产生电流。这个过程通常依赖于贵金属，比如铂。在活体细胞中，酶发挥类似的作用，通过分解糖得到电子进而产生能量。    圣路易斯大学的Shelley D．Minteer说，以前研究人员在燃料细胞中使用酶时，很难维持酶的活性。生物细胞能不停地产生新鲜的酶，但燃料细胞中没有能替换很快降解的酶的机制。 Minteer与同样来自圣路易斯大学的TamaraKlotzbach现在研制了一种聚合物，它能包裹酶并将其保存在用显微镜才能看见的袋子里。Minteer解释说：“我们改造袋子使其能为酶提供理想的微环境。”这种聚合物能使酶保持几个月而不是几天的活性。 在新型燃料细胞中，装有酶的微小的聚合物袋子镶嵌在一张裹在一个电极上的薄膜里。含糖液体中的葡萄糖进入袋子时，酶将其氧化，释放出电子和质子。电子穿过薄膜进入一根导线并通过这根导线到达其他电子。导线中的电子与大气中的氧发生反应产生水。电子在导线中流动形成电流，电流能产生电能。 伊利诺斯大学Urbana-Champaign校区的化学工程师Paul Kenis指出，目前这种新型燃料细胞产生不了多少电能，但它们确实产生了电，这一事实令人激动。Kenis说：“单是使它可以产生电能，就是一项大的成果。” 消耗糖的燃料细胞有可能成为高效的发电工具。糖容易得到，而且消耗糖的新型燃料细胞可生物降解，因此这项技术不会损害环境。  目前，科学家们正试图利用别的能从糖中产生更多电的酶。 他们预计，在不到三年的时间里这种新技术便可在大众化的产品中使用。 Sugar Power for Cell Phones Using enzymes commonly found in living cells, a new type of fuel Cell produces small amounts of electricity from sugar. If the technology is able to succeed in mass production, you may some day share your sweet drinks with your cell phone. In fuel cells, chemical reactions generate electrical currents. The process usually relies on precious metals, such as platinum. In living cells, enzymes perform a similar job, breaking down sugars to obtain electrons and produce energy. When researchers previously used enzymes in fuel ceils, they had trouble keeping them active, says Shelley D. Minteer of St Louis Universlty1. Whereas biological cells continually produce fresh enzymes, there's no mechanism in fuel cells to replace enzymes as they quickly degrade. Minteer and Tamara Klotzbach, also of St Louis University, have now developed polymers that wrap around an enzyme and preserve it in a microscopic pocket. "We tailor these pockets to provide the ideal microenvironment" for the enzyme, Minteer says. The polymers keep the enzyme active for months instead of days. In the new fuel cell, tiny polymer bags of enzyme are embedded in a membrane that coats one of the electrodes. When glucose from a sugary liquid gets into a pocket, the enzyme oxidizes it, releasing electrons and protons. The electrons cross the membrane and enter a wire through which they travel to the other electrode, where they react with oxygen in the atmosphere to produce water. The flow of electrons through the wire constitutes an electrical current that can generate power. So far, the new fuel cells don't produce much power, but the fact that they work at all is exciting, says Paul Kenis, a chemical engineer at the University of Illinois2 at Urbana-Champaign3. "Just getting it to work," Kenis says, "is a major accomplishment. " Sugar-eating fuel cells could be an efficient way to make electricity. Sugar is easy to find. And the new fuel cells that run on it are biodegradable, so the technology wouldn't hurt the environment. The scientists are now trying to use different enzymes that will get more power from sugar. They predict that popular products may he using the new technology in as little as 3 years. 第八篇 引人注目的埃菲尔铁塔 世界各地的人们都来到大约300米高，接近埃菲尔铁塔顶端的地方涂鸦。日本人、巴西人、美国人在这块冰冷的铁上涂上自己的名字、喜好和政治观点，使这最具有法兰西色彩的纪念碑成为动感世界的象征。 从塔上可以看到巴黎市的远景，但奇怪的是观光者们宁愿花时间留下到此一游的痕迹，也不去观赏风景。但这些涂鸦者也引起了一个问：为什么在建成114年后，埃菲尔铁塔仍然这么受欢迎？尽管它在几十年前就已经不是世界上最高的建筑物了。 这个问题的答案就像那构成90层的铁塔的工程一样复杂。一部分的理由是，毫无疑问，铁塔是永不过时的。周期性的维护使得它永远不会被腐蚀掉。埃菲尔铁塔定期油漆，覆盖那些涂鸦，但是它仍将继续存在下去。 “埃菲尔是巴黎的象征，而巴黎又代表了法国。所以，埃菲尔十分具有象征性。”Hugues Richard说道。这位31岁的法国人保持着在19分零4秒的时间内骑行车经过747级台阶登上铁塔上铁塔二层的纪录。“这是铁娘子，能让人产生灵感。”他说。 但是它能使人们产生怎样的灵感呢？毕竟，铁塔并没有任何目的。1930年纽约的Chrysler大厦取代它成为世界上最高的建筑。但是电视和广播信号仍然从塔顶发送出来，而Gustave Eiffel,这个狂热的建造者利用它的高度进行气象学、空气动力学和无线电传输的研究。他在12月台票27日逝世，终年91岁。 本质上来说，铁塔伫立在那儿本身就是一个灵感——它就像一张空白的画布，任游客遐想。对于那些善于从技术角度考虑问题的人来说，它是一个工程上的胜利；而对于恋人们来说，它则象征着浪漫。 “这座塔将在我们所有的人离去后长久存在。”埃菲尔铁塔管理公司的说Isabelle Esnous。 Eiffel Is an Eyeful Some 300 meters up, near the Eiffel Tower’s wind-whipped summit the world comes to scribble. Japanese, Brazilians. Americans—they graffiti their names, loves and politics on the cold iron—transforming the most French of monuments into symbol of a world on the move. With Pairs laid out in miniature below, it seems strange that visitors would rather waste time marking their presence than admiring the view. But the graffiti also raises a question: Why, nearly 114 years after it was completed, and decades after it ceased to be the world’s tallest structure, is la Tour Eiffel still so popular? The reasons are as complex as the iron work that graces a structure some 90 stories high. But part of the answer is, no doubt, its agelessness, regularly maintained, it should never rust away. Graffiti is regularly painted over, but the tower lives on. “Eiffel represents Paris and Paris is France. It is very symbolic,” says Hugues Richard, a 31-year-old Frenchman who holds the record for cycling up to the tower’s second floor—747 steps in 19 minutes and 4 seconds, without touching the floor with his feet. “It’s iron lady, it inspires us,” he says. But to what? After all, the tower doesn’t have a purpose. It ceased to be the world’s tallest in 1930 when the Chrysler Building went up in New York. Yes, television and radio signals are beamed from the top, and Gustave Eiffel, a frenetic builder who died on December 27, aged 91, used its height for conducting research into weather, aerodynamics and radio communication. But in essence the tower inspires simply by being there---a blank canvas for visitors to make of it what they will. To the technically minded, it’s an engineering triumph. For lovers, it’s romantic. “The tower will outlast all of us, and by a long way,” says Isabelle Esnous, whose company manages Eiffel Tower. 第九篇 埃及饱受饥饿折磨 即使古埃及伟大的金字塔建筑者面对那场在公元前2180年促使他们的文明毁灭的饥荒也无能为力，从尼罗河沉淀的泥沙中收集来的证据表明，南面数千公里处的气候的变化是最终的罪魁祸首—同样的或更坏的饥荒在今天仍有可能再次出现。 古代的埃及人依赖于尼罗河每年的洪水来灌溉他们的庄稼。但是，气候的任何变化会促使非洲季风往南吹，直至到埃塞俄比亚外。这些变化可能减弱那些洪水。 埃塞俄比亚高原中降雨量的减少可能意味着用以保持水土的植被的减少。当雨真正下来后，它又可能将大量的土壤冲刷至青尼罗河和埃及，沿途也带上了来自白尼罗河的沉淀物。 青尼罗河里的泥土带有一种不同于白尼罗河泥土的同位素。因此，里德大学的迈克·克罗姆通过分析尼罗河一带沉积泥土同位素的差异计算出来来自不同支流各自沉积物的比例。 克罗姆推理说，在干旱的季节里，青尼罗河里的泥沙相对来说较高。他发现，4200年前-4500年前其中的这样一个时期的干旱后立即跟着发生了古埃及及国王的毁灭。 水势的减弱对埃及人来说具有灾难性的。纽约Lamont Doherty 地球天文台的比尔·雷恩说：“影响食物供应的气候变化不必太大就可以对社会产生‘涟漪式’影响.” 来自华盛顿Smithsonian学会的地质考古学家丹尼尔·斯坦利说：“类似的事件如果发生在今天可能会带来更大的破坏。人类做的任何可以引起气候带转移的事在今天会对尼罗河一带的体系带来更坏的影响，因为那儿的人口数目已经有了非常惊人的、迅速的增长。” Egypt felled by famine Even ancient Egypt’s mighty pyramid builders were powerless in the face of the famine that helped bring down their civilian around 2180BC. Now evidence gleaned from mud deposited by the River Nile suggests that a shift in climate thousands of kilometers to the south was ultimately to blame -- and the same or worse could happen today. The ancient Egyptians depended on the Niles annual floods to irrigate their crops. But any change in climate that pushed the African monsoons southwards out of Ethiopia would have diminished these floods. Dwindling rains in the Ethiopian highlands would have meant fewer plants to establish the soil. When rain did fall it would have washed large amounts of soil into the Blue Nile and into Egypt, along with sediment from the White Nile. The Blue Nile mud has a different isotope signature from that of the White Nile. So by analyzing isotope differences in mud deposited in the Nile Delta, Michael Krom of leeds University worked out what proportion of sediment came from each branch of the river. Krom reasons that during periods of drought, the amount of the Blue Nile mud in the river would be relatively high. He found that one of these periods, from 4,500 to 4,200 years ago, immediately predates the fall of the Egypt’s Old Kingdom. The weakened waters would have been catastrophic for the Egyptians. Changes that affect food supply don’t have to be very large to have a ripple effect in societies, says Bill Ryan of the Lamont Doherty Earth Observatory in New York. “Similar events today could be even more devastating,” says team member Daniel Stanley, a geoarchaeologist from the Smithsonian Institution in Washington, D.C.. Anything humans do to shift the climate belts would have an even worse effect along the Nile system because the populations have increased dramatically. 第一十篇 年轻雌猩猩学习优于她们的弟兄 一项新的研究显示，与年轻雄性相比，年轻雌黑猩猩是更快更好的学习者，这与人类的两性学习差异相仿。 在小雄猩猩玩乐嬉闹时候，雌猩猩却在悉心向母亲学习。结果她们比“男孩们”提早两年学会捕获美味小吃——白蚁。 美国芝加哥林肯公司动物园的Elizabeth Lonsdorf 和她在圣保罗市明尼苏达大学的同事们用了4年时间观察坦桑尼亚Gombe 自然公园的年轻黑猩猩学习它们的“文化行为”。 学习行为的性别差异是“一贯和惊人显著的”，观察小组报告说。研究人员指出，类似的差别也存在于人类儿童写作等技巧的学习过程。他们在《自然》杂志中写道，“基于性别的学习差异因而可以上溯到人类和黑猩猩最近的共同始祖。” 黑猩猩用植物制造灵巧的工具，将它们插入蚁丘把白蚁驱赶出来，再津津有味地享用粘在工具上的白蚁。研究人员用摄像机记录下这种捕食行为，发现每位猩猩母亲在诸如怎样使用不同长度的工具等方面都有她们自己的诀窍。 分析研究六只已知年龄的幼猩猩显示，雌猩猩在平均31个月大时就能成功捕获白蚁，而雄猩猩则需要到58个月时才能学会。雌性每次都能熟练地收获更多的白蚁，并能采用与母亲相似的技巧，而雄性却做不到。 “男孩们”不向母亲学习，却花费大量时间在蚁丘周围嬉戏。研究人员认为玩耍、摇荡等活动或许对公幼兽后来的诸如捕猎、争夺领导权等典型的雄性活动大有裨益。 Lonsdorf 补充说，黑猩猩食物中动物蛋白的主要来源有两个——白蚁和疣猴。“成熟雄性常在树间抓捕疣猴，而雌性则总是因为怀孕或身上吊着小猩猩而难以捕猎，”她说，“成年雌性比雄性花更多的时间捕食白蚁。”因此娴熟地捕获白蚁意味着雌性比雄性吃得更好，“并且可以同时看护后代。雌雄两性似乎都是在十分年幼的时候就开始了与成年后性别角色有关的活动。” Young Female Chimps Outlearn Their Brothers Young female chimps are faster and better learners than young male chimps, suggests a new study, echoing learning differences seen in human girls and boys. While young male chimps pass their time playing. Young female chimps carefully study their mothers. As a result, they learn how to fish for tasty termite snacks over two years before the boys. Elizabeth Lonsdorf, now at Lincoln Park Zoo in Chicago, US, and colleagues at the University of Minnesota, Saint Paul spent four years watching how young chimpanzees in the Gombe National Park in Tanzania learned “cultural behavior”. The sex differences in learning behavior were “consistent and strikingly apparent”, says the team. The researchers point out that similar differences are seen in human children with regard to  skills such as writing. “A sex-based learning differences may therefore date back at least to the last common ancestor of chimpanzees and humans.” they write in the journal Nature. Chimps make flexible tools from vegetation and then insert them into termite mounds, extract them and then munch the termites clinging onto the tool. The researchers used video cameras to record this feeding behavior and found that each chimp mother had her own technique, such as how she used tools of different lengths. Analysis of the six infants whose ages were known showed that girl chimps were an average of 31 months old when they succeeded in fishing out their termites, where the boy chimps were aged 58 months on average. Females were also more skillful at getting out more termites with every dip and used techniques similar to their mothers while males did not. Instead of studying their mothers, the boy chimps spent a significantly greater amount of time frolicking around the termite mound. Behaviors such as playing or swinging might help the male infants later in life when typically male activities like hunting or fighting for dominance become important, suggest the researchers. Lonsdorf adds that there just two main sources of animal protein for chimps — the termites or colobus monkeys. “Mature males often hunt monkeys up trees, but females are almost always either pregnant or burdened with a clinging infant. This makes hunting difficult,” she says .“Adult females spend more time fishing for termites than males.” So becoming proficient at termite fishing could mean adult females eat better, “They can watch their offspring at the same time. The young of both sexes seen to pursue activities related to their adult sex roles{10} at a very young age.” 第一十一篇 申请个人域名的网上费用 一些公司正准备付一万美元在Internet上登录一个域名，尽管并不能保证它们会得到想要的域名。 最近，美国政府和总部在弗吉尼亚的网络解答公司签订了以.com,.org,.edu和.net结尾的域名的登录任务的。合同今年期满，美国政府想实施一项不同的方案。 但在去年，Internet的头面人物组成的特别委员会宣布了它自己的计划。该计划包括建立七种新的域名，每个域名表示使用这一名字的企业或组织的种类。这个委员会吸收了全世界88家公司成为有.firm,.shop,.wed,.arts,.rec,.info扩nom等域名的注册处。美国政府必须同决心书这项计划，但可能仍然推行它最初的计划。尽管这样，88位注册处已经申请了好几个月了。它们预期在这个月开始向从特别委员会中产生的Internet登录委员会登录域名。 为了防止有冲突的域名被登录，委员会将按顺序从每个注册处中取出一个名字，然后回到它们的行列中取第二个名字，如此类推。由于那些公司都尽力购买一个接近行列前头的位置，这导致了一个繁荣的交易。新加坡的全球域名公司索要一万美元以确保对一个域名的申请是第一个被输送到中心数据库。别的注册利对申请排在前排的域名公司索要不可偿还的保证金。帮助建立和监督这项计划的政策监督委员会主席戴维·梅迈厄说，所有的注册处必须遵守当地的消费者保护法和竞争法。但他认为委员会“不应是这方面有强制执行权的单位。” The Net Cost of Making a Name for Yourself Companies are paying up to $10, 000 to register a domain name on the Internet even though there is no guarantee that they will get the name they want. The task of registering domains ending in .com, .org, .edu and .net is at present contracted out by the US government to the Virginia-based company Network Solutions. The contract runs out this year, and the government wants to bring in a different scheme. But last year, an ad hoc committee of the Internet’s great and good revealed its own plan. This involved setting up seven new domains, each indicating the kind of business or organisation using that name. The committee recruited 88 companies around the world to act as registrars for its .firm, .shop, .web, .arts, .rec, .info and .nom domains. The US government has still to give the system its blessing, and may yet push ahead with its original scheme. Despite this, the 88 registrars have been taking applications for several months. They are due to start registering names this month with the Internet Council of Registrars, which grew out of the ad hoc committee. To prevent conflicting names from being registered, the council will take one name from each registrar in turn before going back for the second name in their queues, and so on. This has led to a flourishing trade, with companies trying to buy a place near the head of the queue. Global Names of Singapore is charging $10, 000 to make sure a request for a name is the first one it sends off to the central database. Other registrars are charging nonrefundable deposits for places at the top of the queue. David Maher, chairman of the Policy oversight Committee that is helping to set up and oversee the system, says that all registrars are subject to local laws regarding consumer protection and competition. But he says that the committee “will not act as an enforcement body in this are A.” 第一十二篇 纳佛罗里达遭受冷气团袭击 2003年1月，美国东部2/3的地区处于强冷空气团的控制下，强冷空气团给佛罗里达的柑橘树造成了危胁，同时也使北部的港口被冰冻结。冷空气团让北卡罗来纳州沿岸地区的居民不知所措，不停地铲着尺把深的积雪。 当南方部分地区的气温降到个位数时，冰雪带来的寒意加深了，从南方的大部分地区直到南佛罗里达的腹地地区，气温前所未有地骤降至冰点以下。气温在佛罗里达骤降，西棕榈海岸的气温创纪录地降至2度。 “我们不能相信有那么冷”，这周刚从英国来到奥兰多的马丁·金说，“我们买了运动裤、T恤，但我还不得不出去买件大衣。” 气温的骤降对佛罗里达每年价值91亿美元的柑橘产量造成了危胁，大部分的柑橘还未采摘，果农们正赶着在柑橘被冻坏之前尽可能地多采些。 “时间对柑橘成熟是非常重要的，”果农汤姆·罗根斯说，他预计冷空气会对柑橘和葡萄造成损害。 佛罗里达州州长杰夫·布什签署了一份紧急命令，这个命令取消了对卡车上货物的重量限制，这样，果农们就能使尽可能多的柑橘上市。 佛罗里达州柑橘信托基金会的发言人Casey Pace女士说，果农们用洒水器向果树喷水，这使果树表面形成了一层冰，冰有助于气温维持在冰点附近。如果气温降到-2℃以下超过4个小时，柑橘就会被冻坏。厚度从薄薄一层到30厘米的雪覆盖了卡罗来纳、田纳西和弗吉尼亚的部分地区。 Florida Hit by Cold Air Mass In January, 2003, the eastern two-thirds of the United States was at the mercy of a bitterly cold air mass that has endangered Florida’s citrus trees, choked northern harbors with ice and left bewildered residents of North Carolina’s Outer Banks digging out of up to a foot of snow. The ice chill deepened as temperatures fell to the single digits in most of the South, with an unfamiliar dip below the freezing mark as far south as parts of interior South Florida. Temperatures in Florida plunged, with West Palm Beach dropping to a record low of 2 degrees. “We couldn’t believe how cold it was,” said Martin King, who arrived this week in Orlando from England. “we brought shorts, T-shirt, and I had to go out and buy another coat. ” The temperature plunge posed a threat to Florida’s US$9.1 billion-a-year citrus crop, more of which is still on the trees. Growers were hurrying to harvest as much of the fruit as possible before it was damaged by cold. “Time is of the essence in getting fruit to the plant,” said Tom Rogers, a citrus grower who expected to see damage to oranges and grapefruit at that time. In Florida, Governor Jeb Bush signed an emergency order to eliminate the weight limit on trucks so citrus growers could get as much fruit to market as possible. Casey Pace, a spokeswoman for Florida Citrus Mutual, said growers had sprayed trees with sprinklers, which created a layer of ice and helped maintain a temperature near freezing. Citrus trees are considered in danger of damage if the temperature drops below minus 2 degrees Celsius for four hours or more. Snow ranging from a dusting to up to 30 centimeters blanketed the Carolinas, Tennessee and parts of Virginia. 第一十三篇 隐形环 到目前为止，科学家还不能造出哈利；波特使用过的隐身斗篷。但是他们率先研制出了一种与其类似的装置，这种装置能使自身和置于其中的物体不受微波的探测。 当一个人“看”某物体时，他的眼睛就会感知到从那个物体反射过来的光波。眼睛和大脑一同工作，编辑这些光感并重建其原貌。所以，如果要让一个物体隐形，科学家们就必须阻止光波反射。并且他们得确保此物体没有阴影。否则，反射光的缺失会使物体显现。  鉴于人眼对光波的感知性，要想隐形某物体很难做到，但对微波就可以做到。如同可见光，微波是一种辐射能。他们是电磁波谱的一部分，其中也包括无线电波、红外线光、紫外线、x射线和伽马射线。微波的波长比无线电波短，但比可见光长。    科学家研制出的这种新型隐身装置和杯垫一般大小，形状像个环。由于它是特殊材料制成，因此具有非同寻常的功能。当微波射向它时，仅有极少的光会反射回去，这些光会从一端穿过这个环，并在此过程中沿着弯曲的路线前进，直到抵达另一端。最后光波回到原来的路线。 对于在环的另一端放置的探测器来说，光波看上去就像从来没有改变过路径一样，即好像没有遇到障碍物。这样一来，这个环就如同没有存在过。 研究者又将一个铜线圈放进环里，依然得到同样的结果。不过，这个环和里面的东西还是会留下一点影子。环形隐身器只能作用于微波，而不能作用于可见光及电磁波。因此，哈里，波特的隐形斗篷目前还没有竞争对手。 Invisibility Ring Scientists can't yet make an invisibility cloak1 like the one that Harry Potter2 uses. But, for the first time, they've constructed a simple cloaking device that makes itself and something placed inside it invisible to microwaves. When a person "sees" an object, his or her eye senses many different waves of visible light as they bounce off the object. The eye and brain then work together to organize these sensations and reconstruct the object's original shape. So, to make an object invisible, scientists have to keep waves from bouncing off it. And they have to make sure the object casts no shadow. Otherwise, the absence of reflected light on one side would give the object away. Invisibility isn't possible yet with waves of light that the human eye can see. But it is now possible with microwaves. Like visible light, microwaves are a form of radiant energy. They are part of the electromagnetic spectrum, which also includes radio waves, infrared light, ultraviolet rays, X rays, and gamma rays. The wavelengths of microwaves are shorter than those of radio waves but longer than those of visible light. The scientists' new "invisibility device" is the size of a drink coaster and shaped like a ring. The ring is made of a special material with unusual ability. When microwaves strike the ring, very few bounce off it. Instead, they pass through the ring, which bends the waves all the way around until they reach the opposite side. The waves then return to their original paths. To a detector set up to receive microwaves on the other side of the ring, it looks as if the waves never changed their paths — as if there were no object in the way! So, the ring is effectively invisible. When the researchers put a small Copper loop inside the ring, it, too, is nearly invisible. However, the cloaking device and anything inside it do cast a pale shadow. And the device works only for microwaves, not for visible light or any kind of electromagnetic radiation. So, Harry Potter's invisibility cloak doesn't have any real competition yet. 第一十四篇 日本用来监视醉酒司机的新型概念车 日本日产公司日前开发了一种新型概念车，这种车含有呼气酒精检测器和其他一些装置，用来防止那些醉酒和过于疲劳的司机上路驾驶。 车上的传感器能检测出车中的酒气，并通过监测司机身上的汗味探知酒精度。车中的电脑系统能报警，甚至还能在司机超速行驶时锁住引擎。这个气味传感器被牢牢固定在驾驶员和乘客的座位上。另一个探测器装在车的换档把手上，用来测试司机的掌心的汗液。 其他的汽车制造商们也开发了类似的探测系统。比如，瑞典的沃尔沃在汽车的安全带上安装了很多呼气酒精检测器，司机在开车前必须向里吹气。 这种新型概念车还在仪表盘上装有照相机，通过监测驾驶员的双眼探知其清醒程度。如果发现司机需要停车休息，便用英语或日语发出警告。 汽车监测技术仍在发展，总裁Kazuhiro Doi指出：综合多种探测技术将对整体技术水平的提高更为有利。例如，若是换档装置探测器被乘客代用，面部识别技术仍能受用。日产公司并没有明确将此项技术推向市场的时间，只是试图借助此项技术在2015年把死亡率降到1995年的一半。 如若探知司机昏昏欲睡，安全带会自动收紧，外部照相机也会检查汽车是否偏离路线。尽管如此，Doi承认有一些技术，如气味传感器仍有待改进。因为对很多人来说，往往只喝—口都会被检测出来。为避免这类事件的发生，必须研究激活系统的最低限度。 在英国，一些组织正在运用类似的先进技术来研究司机的行为和路标设置的有效性。 Japanese Car Keeps Watch for Drunk Drivers A concept ear developed by Japanese company Nissan1 has a breathalyzer-like detection system and other instruments that could help keep drunk or over-tired drivers off the road. The car's sensors check odors inside the car and monitor a driver's sweat for traces of alcohol. An in-car computer system can issue an alert or even lock up the ignition system if the driver seems over-the-limit. The air odor sensors are fixed firmly and deeply in the driver and passenger seats, while a detector in the gear-shift knob measures perspiration from the driver's palm. Other carmakers have developed similar detection systems. For example, Sweden's Volvo2 has developed a breathalyzer attached to a Car's seat belt that drivers must blow into before the engine will start. Nissan's new concept vehicle also includes a dashboard-mounted camera that tracks a drivers alertness by monitoring their eyes. It will sound an alarm and issue a spoken warning in Japanese or English if it judges that the driver needs to pull over and rest3. The car technology is still in development, but general manager Kazuhiro Doi says the combination of different detection systems should improve the overall effectiveness of the technology. "For example, if the gear-shift sensor was bypassed by a passenger using it instead of the driver, the facial recognition system would Still be used," Doi says. Nissan has no specific timetable for marketing the system, but aims to Use technology to cut the number of fatalities involving its vehicles to half 1995 levels by 2015. The ear's seat belt can also tighten if drowsiness is detected, while an "external camera checks that the car is keeping to its lane properly. However, Doi admits that some of the technology, such as the alcohol odor sensor, should be improved. "If you drink one beer, it's going to register, so we need to study what's the appropriate level for the system to activate," he says. In the UK4 , some research groups are using similar advanced techniques to understand driver behavior and the effectiveness of different road. designs. 第一十五篇 肋生双翅机器人学飞行 自然界中的飞行学习经历了几百万年的反复实践和磨练，而安装机翼的机器人仅在数小时内就成功实现突破，用的是同进化原理。 瑞典Gothenburg Chalmers科技大学的Krister Wolff 和Peter Nordin 研制出带翼的机器人，着手测试它能否在不预设振翅数据程序的条件下自行学会飞行。 首先，机器人只是飘忽不定地振动盘桓，不过它的运动逐渐获得了上升高度，起初，它想走走捷径，试图仅用翅尖保持直立。然而三小时后，它放弃了这种方法， 转用更有效的振翅技术，90度角旋转两翼，并在它们恢复到水平位置将其拉起。 “事实告诉我们，飞行装置有可能实现这种进化。”Peter Bentley 说。他现正在伦敦大学研究进化计算技术。虽然机器人可以摸索出上升飞行的最佳方式，却不会起飞。“进化升级所做的只有这么多，”Bentley说，“这东西不可能自行起飞，因为发动机不能产生足够动力。” 机器人的两翼由轻木制成，长约一米，覆有一层轻塑胶。它的小马达使机翼可以前后上下运动，并能在这两个方向上任意旋转。 研究小组将机器人附着在两根竖直标杆上，它便能上下滑动。实验刚开始的时候，机器人悬挂在一根弹性带上。一旦它升高，运动探测器就能测量它任何运动的高度。 每过20秒，计算机程序就给机器人输入任意设定的指令，以检测其振翅能力。每个指令或是让机器人停止运动或是在各种方向上转动机翼。 通过来自运动探测器的反馈，程序测算出哪几组指令能最有效地产生高度。最成功的几组进行配对，而其“后代”指令则通过在成功组合间随意交换指令产生。在产生下一代组合之前，这些第二代指令被发往机器人并进行评估，然后这一过程反复进行。 Winged Robot Learns to Fly Learning how to fly took nature millions of years of trial and error—but a winged robot has cracked it in only a few hours, using the same evolutionary principles. Krister Wolff and Peter Nordin of Chalmers University of Technology (CUT) in Gothenburg, Sweden, built a winged robot and set about testing whether it could learn to fly by itself, without any pre-programmed data on what flapping is or how to do it. To begin with, the robot just twitched and jerked erratically. But, gradually, it made movements that gained height. At first , it cheated — simply standing on its wing tips was one early short cut. After three hours, however, the robot abandoned such methods in favor of a more effective flapping technique, where it rotated its wings through 90 degrees and raised them before twisting them back to the horizontal and pushing down. “This tells us that this kind of evolution is capable of coming up with flying motion,” says Peter Bentley, who works on evolutionary computing at University College London. But while the robot had worked out how best to produce lift, it was not about to take off. “There’s only so much that evolution can do, Bentley says. This thing is never going to fly because the motors will never have the strength to do it,” he says. The robot had metre-long wings made from balsa wood and covered with a light plastic film. Small motors on the robot let it move its wings forwards or backwards, up or down or twist them in either direction. The team attached the robot to two vertical rods, so it could slide up and down. At the start of a test, the robot was suspended by an elastic band. A movement detector measured how much lift, if any, the robot produced for any given movement. A computer program fed the robot random instructions, at the rate of 20 per second, to test its flapping abilities. Each instruction told the robot either to do nothing or to move the wings slightly in the various directions. Feedback from the movement detector let the program work out which sets of instructions were best at producing lift. The most successful ones were paired up and “offspring” sets of instructions were generated by swapping instructions randomly between successful pairs. These next-generation instructions were then sent to the robot and evaluated before breeding a new generation, and the process was repeated. 第一十六篇 日本人的地心旅行 就像进行一次地心旅行，日本科学家进行了世界上的首次尝试，在炙热的火山核心钻孔，从而揭开了火山致命喷发的秘密。 日本Unzen山繁茂的山坡上，伫立着一个高达50米，犹如石油钻探平台的钻塔。下周，它将钻透火山壳，试图采集下面沸腾的火山岩浆的样本。 研究工作小组的负责人，来自东京大学地震研究中心的Setsuya Nakata表示，这次任务的目的是要研究液化岩石如何导致威胁性气体的积聚。 “气体积聚很重要，因为它控制着火山喷发的爆炸性。”他说，“研究的结果还可以用于防灾研究。” Unzen山是一座高达1,485米的圆顶山，它位于南部的Kyushu岛，是一个极佳的模型，1991年，它喷发出的热岩浆覆盖了附近的小城，造成了43人死亡，将近2,300人无家可归，到1995年它恢复平静时，又有11,000人从这五地区疏散。 研究结果对于像日本这样拥有20座被气象局监控的危险山峰的国家来说，尤为重要，日本最著名的火山也许就是被冰雪覆盖的富士山。它上一次喷发是在1707年，火山灰喷洒到东京。 钻探工作将很快从Unzen山的西北坡上850米的高度开始。到八月底，科学家希望在约为海平面高度的地方引出一个岩浆口，到2004年夏末，提取长度为200米的样本。 由于岩浆有将近700度的高温，在那个高度进行钻探是不可能的。所以，泥浆将被抽进钻孔机，用来冷却岩浆，以保证钻头的顺利工作。 Nakata说，不存在引发火山新一轮爆发的危险性。 Japanese Drilling into Core of Earth In what reassembles a journey to the center of the Earth, Japanese scientists have launched the world’s first attempt to bore a hold into the red-hot core of a volcano and unlock the secrets of deadly eruption. A50-meter-high oil-rig-like derrick perched on the scrubby slopes of Japan’s Mount Unzen will begin drilling through the volcano’s crust next week in a bid to sample the magma bubbling below2. The aim is to study how the liquefied rock causes menacing gas buildup, said team leader Setsuya Nakata, of the University of Tokyo’s Earthquake Research Institute. “Gassing is important because it controls the explosivity of eruptions,” Nakata said. “The results can be expanded to anti-disaster research.” Mount Unzen, a wind-swept 1,486-meter dome on the southern island of Kyushu, is a perfect model. It erupted in 1991, showering avalanches of hot rocks over a nearby town, killing 43 people and leaving nearly 2,300 homeless. Another 11,000 people were evacuated from the area until 1995, when the volcano had stabilized. The results are particularly important to a nation like Japan, where the meteorological agency monitors 20 dangerous peaks. Perhaps Japan’s most famous volcano is snowcapped Mount Fuji, which last erupted in 1707 and sprinkled Tokyo with ash. The drilling on Mount Unzen will begin very soon from an altitude of 850 meters on its northwest slope. Scientists hope to tap a magma vent around sea level by August and extract a 200-meter-long core sample by summer 20043. Boring into the glowing magma at that level would normally be impossible, because of its fiery 700 degree Celsius heat. Thus, a slurry of water will be pumped into the drill shaft to cool the magma and allow the drill head to cut through. Nakata said there is no danger of triggering another eruption4. 第一十七篇 地球防晒霜 就算怀着最美好的愿望，仅仅减少二氧化碳的排放量还是不能制止全球变暖。很明显，即便采取最强硬的措施来控制排放，气候的变化无常仍能导致极速变暖和海平面上升。另一方面，受到政府和特殊利益群体的阻挠，气候学家往往不能将措施很快实施彻底。    ’ 幸好，如果被逼上绝路，科学家们还有最后几招。在大多数情况下，他们拒绝讨论这些施，害怕人们会因此沾沾门喜而使这个问题不能被彻底解决。至少目前是这样。越来越多的研究者相信一项大型的地质丁程建设可用来抵御全球变暖。斯坦福大学的一位气象学家Stephen Schneider最早提出气候变暖这项议题的学者之一。他说：“我把它比作美沙酮。如果你那里有一个海洛因瘾者，那么正确的治疗方法就是住院，接受长时间的康复治疗。拒绝正常住院治疗，那服用美沙酮是一种缓解海洛因毒瘾的有效方法。” 总体思路是给地球也涂上防晒霜。一个天文学家突发奇想，想借此冷却地球：发射亿万轻如羽毛的碟片进入太空形成巨大“云层”以阻碍太阳光。这个想法备受争议，但最近的研究表明，有—些方法可以控制到达地球表面的阳光以抵消温室效应产生的气候变暖。全球气候模型表明，阻断百之一点八的太阳能刚好可以抵消大气中双倍的温室气体所引起的气候变暖现象。这个想法影响深远，因为即使采取最严格的控制气体排放措施，到本世纪末，二氧化碳量仍会翻倍。并且这种情况将再持续至少一个世纪。 A Sunshade for the Planet Even with the best will1 in the world, reducing our carbon emissions is not going to prevent global warming; It has become clear that even if we take the most strong measures to control emissions, the uncertainties in our climate models still leave open the possibility of extreme warming and rises in sea level. At the same rime, resistance by governments and special interest groups makes it quite possible that the actions suggested by climate scientists might not be implemented soon enough. Fortunately, if the worst comes to the worst2, scientists still have a few tricks up their sleeves3. For the most part they have strongly resisted discussing these options for fear of inviting a sense of complacency that might thwart efforts to tackle the root of the problem. Until now, that is. A growing number of researchers are taking a fresh look at large-scale "geocngineering" projects that might be used to counteract global warming. "I use the analogy of methadone1 ," says Stephen Schneider, a climate researcher at Stanford University in California who was among the first to draw attention to global. warming. "If you have a heroin addict, the correct treatment is hospitalization, and a long rehab. But if they absolutely refuse, methadone is better than heroin. " Basically the idea is to apply "sunscreen" to the whole planet. One astronomer has come up with a radical plan to cool Earth: launch trillions of feather-light discs into space, where they would form a vast cloud that would block the sun's rays. It's controversial, hut recent studies suggest there are ways to deflect just enough of the sunlight reaching the Earth's surface to counteract the warming produced by the greenhouse effect. Global climate models show that blocking just 1.8 per cent of the incident energy in the sun's rays would cancel out the warming effects produced by a doubling' of greenhouse gases in the atmosphere. That could be crucial, because even the most severe emissions-control measures being proposed would leave us with a doubling of carbon dioxide by the end of this century, and that would last for at least a century more. 第一十八篇 石油匮乏 全世界每天都要消耗相当于亿桶石油的能源。地球上的大部分能源来自于太阳。事实上，每分钟到达地球表层的来自于太阳的能源就足已满足我们一整年的需求，我们只是需要有效地加以利用而已。到目前为止，石油一直是一种较便宜、易获得的能源。但当供应缩减时，情况就会改变，我们就不能像现在这样不加节制地消耗石油了。 在蒸汽工业命时代，高能煤成为首选燃料之前，燃木能满足大部分能源需求。现在，煤仍然大量地运用于发电站，满足我们四分之一的能源需求。但自从我们开始大量开采石油后，煤的使用就已经在逐渐衰退。煤是使用效率最低、最不健康、最不环保的化石燃料，但因其供应充足——煤的储量是石油的6倍，煤的使用量又有所回升。 今天，石油作为一种从地表层挖掘出，用于生产汽油、柴油和其他各种化学物质的矿物油，供应着大约40%的世界能源需求，其中大部分用于供给机动车辆；美国消耗着世界四分之一的石油，同时排放出大约全球1/4的温室气体。  大部分的石油来自中东，牛东拥有50％的世界已勘探石油储存量。其他的石油产地包括俄罗斯、北美、挪威、委内瑞拉和北海。阿拉斯加北极国家野生动物保护区最新成为美国能源的又一主要供应地，减少了美国对国外进口石油的依赖。 尽管和评价各有不同，但大多数专家预测人类将在50年之内轻而易举地耗尽现行的所有储备石油。未来的几十年，当供不应求时我们会很快陷入能源危机。当常规能源不容易获得时，代之使用的可能是诸如油页岩和沥青砂等能源。石油也可从煤中提炼获得。 自从我们开始使用化石燃料，我们已经释放出4000亿吨碳。当化石燃料全部用完时，世界温度将上升13摄氏度。更恐怖的是，这将会导致所有热带雨林的破坏和北极冰的溶解。 Thirst for Oil Worldwide every day, we devour the energy equivalent of about 200 million barrels of oil. Most of the energy on Earth comes from the Sun. In fact enough energy from the Sun hits the planet's surface each minute to cover our needs for an entire year, we lust need to find an efficient way to use it. So far the energy in oil has been cheaper and easier to get at.  But as supplies dwindle, this will change, and we will need to cure our addiction to oil. Burning wood satisfied most energy needs until the steam-driven industrial revolution, when energy-dense coal became the fuel of choice. Coal is still used, mostly in power stations, to cover one quarter of our energy needs, but its use has been declining since we started pumping up oil. Coal is the least efficient, unhealthiest and most environmentally damaging fossil fuel, but could make a comeback, as supplies are still plentiful: its reserves are five times larger than oil's. Today petroleum, a mineral oil obtained from below the surface of the Earth and used to produce petrol, diesel oil and various other chemical substances, provides around 40% of the world's energy needs, mostly fuelling automobiles. The US consumes a quarter of all oil, and generates a similar proportion of greenhouse gas emissions. The majority of oil comes from the Middle East, which has half of known reserves. But other significant sources include Russia, North America, Norway, Venezuela and the North Sea. Alaska's Arctic National Wildlife Refuge1 could be a major new US source, to reduce reliance on, foreign imports. Most experts predict we will exhaust easily accessible reserves within 50 years, though. opinions and estimates vary. We could fast reach an energy crisis in the next few decades, when demand exceeds supply.  As conventional reserves become more difficult to access, others such as oil shales and tar sands may be used instead. Petrol could also be obtained from coal. Since we ,started using fossil fuels, we have released 400 billion tonnes2 of carbon, and burning the entire reserves could eventually raise world temperatures by 13℃, Among other horrors, this would result in the destruction of all rainforests and the melting Of all Arctic ice. 第一十九篇 延长人类寿命 人类生命的延长使人口增加了。许多现在还活着的人，如果早出生100年的话，可能在幼年就得病死了。因为活得长的人越多，在任何一个特定的时间里的人也就越多。实际上导致人口爆炸的是死亡率的降低而不是出生率的增长。 延长人的生命同时也使抚养人口数量增长了。在所有的社会里，残疾的，太小或太老的以至不能工作的人，要靠社会中的其他人的救助。在以狩猎和采集为生的时代，不能跟上其他的人的老人会被甩在后面，任他死去。在饥荒年代，人们允许婴儿死，因为如果它的父母饿死了，它也活不成，但是如果它的父母活下来了，他们还可以再要个孩子。在大部分的当代社会里，人们觉得在道义上负有让人们活着的义务，不管他们能不能工作。现在有许多人已经过了想工作或能工作的年龄；我们也制定了让人们在特定年龄退休的规章制度。除非这些人为他们退休后的生活攒够了钱，否则别人就得负担他们。在美国，许多退休的老人靠很少的一点社会保障金过日子，生活几近赤贫。老年人比年轻人或中年人更容易得病；除非他们很有钱，或有私人或政府的保险金，否则他们在得重病的时候就得靠福利救济。 当老年人变得衰老，或太虚弱，病太重以至不能照料自己时，他们就给他们的家庭带来了很严重的问题，在过去和一些流传的习俗里，他们会在家中得到照料直到死去。现在，由于大部分的家庭成员都在工作或上学，所以常常没有人在实照料病弱的人。为满足这种需要，许多养老院和康复医院被建立起来。这些机构通常是赢利的，尽管其中有一些是宗教及其他非赢利团体资助的。然而只有少数的这样的机构是好的，它们大部分是垂死的人的“垃圾场”，里面的工作是由一些低工资、大劳动量的、没有技术的人做的。 Prolonging Human Life Prolonging human life has increased the size of the human population. Many people alive today would have died of childhood diseases if they had been born 100 years ago. Because more people live longer, there are more people around at any given time. In fact, it is a decrease in death rates, not an increase in birth rates, that has led to the population explosion. Prolonging human life has also increased the dependency (依赖) load. In all societies, people who are disabled or too young or too old to work are dependent on the rest of society to provide for them. In hunting and gathering cultures, old people who could not keep up might be left behind to die. In times of famine (饥荒), infants might be allowed to die because they could not survive if their parents starved, whereas if the parents survived they could have another child. In most contemporary societies, people feel a moral obligation to keep people alive whether they can work or not. We have a great many people today who live past the age at which they want to work or are able to work; we also have rules which require people to retire at a certain age. Unless these people were able to save money for their retirement, somebody else must support them. I the United States many retired people love on social security checks which are so little that they must live in near poverty. Older people have more illness than young or middle-aged people; unless they have wealth or private or government insurance, they must often go on welfare if they have a serious illness. When older people become senile (年老的) or too weak and ill to care for themselves, they create grave problems for their families. In the past and in some traditional cultures, they would be cared for at home until they died. Today, with most members of a household working or in school, there is often no one at home who can care for a sick or weak person. To meet this need, a great many nursing homes and convalescent hospitals (康复医院) have been built. These are often profit-making organizations, although some are sponsored by religious and other nonprofit groups. While a few of these institute ons are good, most of them are simply dumping grounds for the dying in which care is given by poorly paid, overworked and underskilled personnel. 第二十篇 深海探索器 海洋覆盖了我们地球三分之二的面积，但被开发的地下水却只有很小—部分。目前，马萨诸塞木洞海洋研究所的科学家们正在开发一种能载探索家们深入水下6500米(21 320英尺)的水下交通丁具。作为一种载人潜艇或人丁操作丁具，这种新的机器将替代世界上第—个深海潜水器Alvin”。 Alvin潜水器已经保持了惊人的纪录，在各种重要的深海考察中发挥着重要作用。Alvin潜水器已经运行了40年，但它只能深入水下4 500米(14 784英尺)。木洞海洋协会的研究家们说，潜水于具该升级了。    Alvin潜水器下水始于1964年。海洋地质学家兼木洞海洋学研究所深海探索协会主任Daniel Fornari说，自1964年后，Alvin潜水器每年运行200～250天。在整个航程巾，它载12 000人进行过3 000多。次潜水。 Fornari说，新式的Alvin潜水器必将揭示这个依旧充满神秘的水下世界的许多奇妙之处。它也可能会使水下探索更容易些。Fornari说：“我们在陆上把许多东西想当然，我们会四处行走，用我们的双眼看周围的东西的大小。我们会看到各种颜色，各种特殊的布置。” 这种新的人下操作机器与Alvin潜水器很相似，大小适中。长约37英尺，里面环境将是个小球体，约8英尺宽。和Alvin一样，它将载一名宇航员和两名乘客，可调动。其他方面，它将使乘客有更多机会欣赏风景，因为旧式Alvin潜水器只有三个窗户，新式的将有五个窗户，其中有很多折叠，乘客和宇航员可以看见相同的事物。  旧式Alvin潜水器可以每秒上下30米，最快时速是2节(约2．3英里/小时)；而新式潜水器将能每秒上下44米，它最快时速将达到3节(3．5英里／小时)。 Explorer of the Extreme Deep Oceans cover more than two-thirds of our planet.  Yet, just a small fraction of the underwater world has been explored. Now, Scientists at the Woods Hole1 Oceanographic Institution (WHOI) in Massachusetts are building an underwater vehicle that will carry explorers as deep as 6,500 meters (21,320 feet). The new machine, known as a manned submersible or human-operated vehicle (HOV), will replace another tree named Alvin2 which has an amazing record of discovery, playing a key role in various important and famous undersea expeditions. Alvin has been operating for 40 years but can go down only 4,500 meters (I4,784 feet). It's about time for an upgrade, WHOI researchers say. Alvin was launched in 1964. Since then, Alvin has worked between 200 and 250 days a year. says Daniel Fornari, a marine geologist and director of the Deep Ocean Exploration Institute at WHOI. During its lifetime, Alvin has carried some 12,000 people on a total of more than 3,000 dives.  A newer, better versions of Alvin is bound to reveal even more surprises about a world that is still full of mysteries, Fornari says. It might also make the job of exploration a little easier. "We take so much for granted on land," Fornari says. "We can walk around arid see with our eyes how big things are. We can see colors,  special arrangements. " Size-wise, the new HOV will be similar to Alvin. It'll be about 37 feet long. The setting area inside will be a small sphere, about 8 feet wide, like Alvin, it'll carry a pilot and two passengers. It will be just as maneuverable. 'In most other ways, it will give passengers more opportunities to enjoy the view, for one thing. Alvin has only three windows, the new vehicle will have five, with more overlap so that the passengers and the pilot can see the same thing. Alvin can go up and down at a rate of 30 meters every second, and its maximum speed is2 knots (about 2.3 miles per hour), while the new .vehicle will he able to ascend and descend at 44 meters per second. It'll reach speeds of 3 knots, or 3. 5 miles per hour. 第二十一篇 植物，沼气的又一来源 德国马克思·普朗克核物理研究所地球化学家Frank Keppler提到，科学家已经研究沼气几十年，但一直没认为植物能产生沼气。现在Keppler和同事们发现从草到树的植物也可能是温室气体的来源。这的确是令人惊讶的，阅为大多数科学家认为沼气是在缺氧环境中产生的。 以前，研究人员认为植物不可能产㈩大量的气体。他们认为微生物需要在无氧环境下生产沼气。沼气和二氧化碳一样都是温室气体，它们在地球大气中吸收热量导致全球变暖。 在实验中，Keppler一组使用内含与地球大气中同等密度氧的密闭室来测量从活植物和干植物如落叶中释放的沼气量。 研究人员测量干植物时温度在30摄氏度到70摄氏度。3()摄氏度时，他们发现一克干植物每小时释放3微克沼气(1微克是1克的十亿分之一)。温度每上升10度，每小时释放的沼气量约会增加一倍。 对于正常温度下生长的活植物，每一克植物组织每小时释放出370微克的沼气。当活的或者死的植物暴露在阳光下时，沼气释放量会增加两倍。 由于有大量的氧气，正常生产沼气的细菌不可能加入。在对生长在水中而不是土壤中的植物进行实验时也发现有沼气释放。这也表明气体产生于植物而不是土壤微生物。 圣保罗明尼苏达州大学：生物地球化学家Jennifer Y．King说，这些新发现是一项“有趣的观察记录”。因为一些土壤微生物消耗沼气，它们会阻止植物产生的沼气到达大气中。Jennifer Y．King指出，需要对土地进行测试以判定植物的影响。 Plant Gas Scientists have been studying natural sources of methane for decades but hadn't regarded plants as a producer, notes Frank Keppler, a geochemist at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany1. Now Keppler and his colleagues find that plants, from grasses to trees, may also be sources of the greenhouse gas. This is really surprising. because most scientists assumed that methane production requires an oxygen-free environment. Previously, researchers had thought that it was impossible for plants to make significant amounts of the gas. They had assumed that microbes2 need to be in environments without oxygen to produce methane. Methane is a greenhouse gas, like carbon dioxide. Gases such as methane and carbon dioxide trap heat in Earth's atmosphere and contribute to global warming. In its experiments.  Keppler's team used sealed chambers that contained the same concentration of oxygen that Earth's atmosphere has. They measured the amounts of methane that Were released by both living plants and dried plant material, such as fallen leaves. With the dried plants, the researchers took measurement at temperatures ranging from 30 degrees Celsius to 70 degrees C. At 30 degrees C. they found, a gram of dried plant material released up to 3 nanograms of methane per hour. (One nanogram is a billionth of a gram. ) With every 10-degree rise in temperature, the amount of methane released each hour roughly doubled. Living plants growing at their normal temperatures released as much as 370 nanograms of methane per gram of plant tissue per hour. Methane emissions tripled when living and dead plant was exposed to sunlight. .Because there was plenty of oxygen available, it's unlikely that the types of bacteria that normally make methane were involved.  Experiments on plants that were grown in water rather than soil also resumed in methane emissions. That's another strong sign that the gas came from the plants and not soil microbes. The new finding is an "interesting observation," says Jennifer Y. King, a biogeochemistry at the University of Minnesota in St. Paul3. Because some types of soil microbes consume methane, they may prevent plant-produced methane from reaching the atmosphere. Field tests will be needed to assess the plant's influence, she notes. 第二十二篇 雪  花 你可能听说过没有两片雪花是完全相同的。当然，没有人曾经检查过每年飘落在地球上的数以万亿计的雪花来证实这一说法。然而，加州技术学院的Kenneth Libbrecht教授仍相信这一说法的真实性。 Libbrecht说，雪花并不是片状的。它们在基础阶段是结晶状的。每一片雪花的晶格都是六边形的。最简单的雪晶体是六边的扁平碟状和六边的柱状。这种晶体在极寒极干的地方十分普遍。当这种简单的六边对称形状发生变化时，雪晶体就拥有了它们独特的美丽之外。在适当的条件下，结晶体的每个角都向外伸长，形成臂状物。在大约几分钟的时间内，这些臂状物变得非常华美，结晶体也变得像星星般闪闪发亮。 环境中的几个因素影响了雪晶体的形状及形成速度。其中之一是湿度。当湿度增加时，晶体变化得更快并且形成更为复杂的形状。另一个因素是气温。云里的水蒸气分子集结在尘埃上，冷凝形成简单的晶体，此时，雪花就诞生了。初形成的晶体在云里四处碰撞，穿过不同Libbrecht说，当这些晶体遇到大约零下15度的空气团时，它们就会快速变化，伸长出六个臂状物。这时，如果晶体遇到一个温度更高的空气团（比如零下10度），这些臂状物的尖端就会很快停止伸长，形成碟状的六边形。这时，如果遇到温度更高的空气团（比如零下5度），它的顶部和底部会比两边更快地停止伸长，从而在形状上更像一个柱形。 在雪花的一生中，雪晶体可能遇到许多温度更高或更低的空气团，形成独特而又复杂的生长史。这使得雪花不尽相同。雪花的每一个臂状物看起来都十分相像。但晶体本身却是各式各样的。 利用冷却槽，Libbrecht发现了如何制造各种形状的雪晶体，碟状、柱状、针状的等等。Libbrecht还改进了他的技术，使得晶体之间更加相像。然而，他仍然无法制造两片完全相同的雪花。湿度与温度的细微差别就会改变晶体的形成过程。 Snowflakes You’ve probably heard that no two snowflakes are alike. Of course, nobody has ever confirmed that statement by examining every one of the estimated one septillion snowflakes that drift to Earth each year. still, Kenneth Libbrecht, a professor at the California Institute of Technology, is confident that the statement is true. Snowflakes aren’t flaky, says Libbrecht. At their basic level, they’re crystalline. The lattice of every snowflake is six-sided in shape. The simplest snow crystals are six-sided flat plates and six-sided columns. Such crystals are common in places where the air is extremely cold and dry. Snow crystals acquire their special beauty when their simple six-sided symmetry blossoms. Under the right conditions, each of the six corners of a crystal sprouts what is called an arm. In a matter of minutes, the arms can become highly ornate and give the crystal a star like appearance. Several factors in the environment affect the shape and growth rate of a snow crystal. One factor is humidity. Crystals grow faster and in more intricate shape as humidity increases. A second factor is air temperature. A snowflake is born when several molecules of water vapor in a could land on a speck of dust and freeze to form a simple crystal. As the young crystal bops around in the cloud, it passes through air pockets of varying temperatures. If the crystal passes through a pocket of air that is, says,—15 degrees Celsius, it will grow quickly and sprout six arms, says Libbrecht. If the crystal is then tossed into a warmer pocket, one about-10℃, the arms’ tips will stop growing quickly and form six-side plates. If the crystal then drifts into an even warmer pocket of about -℃, its top and bottom will grow more quickly than its sides and become more column like in shape.