磁悬浮列车为何没有全面普及？
字幕摘录
| 时间 | 英文 | 中文 |
|---|---|---|
| 0:00 | To coincide with the 1964 Tokyo Olympics, | 为了配合1964年东京奥运会 |
| 0:04 | Japan launched the world's first high-speed train, the Shinkansen. | 日本推出世界首列高速列车申坎森号. |
| 0:10 | Capable of running at 210 kilometers per hour, | 以每小时210公里的速度运行, |
| 0:14 | this groundbreaking bullet train inspired countries around the world | 这辆突破性子弹列车启发了世界各国 |
| 0:19 | to invest in high-speed rail. | 投资高速铁路. |
| 0:22 | Today, these trains regularly travel at over 300 kilometers per hour, | 今天,这些列车定期以每小时300公里的速度行驶, |
| 0:29 | on par with the takeoff speed of a commercial airplane. | 与商业飞机的起飞速度相当 |
| 0:33 | But could these trains go even faster, | 但是这些火车能开得更快吗? |
| 0:36 | whisking passengers to their destinations quicker than the smoothest flight? | 比最顺利的飞行快吗? |
| 0:42 | To answer this, it helps to understand how these trains reach | 为了回答这个问题,它有助于理解这些列车是如何到达的 |
展开字幕全文（70 条）
| 序号 | 英文 | 中文 |
|---|---|---|
| 1 | To coincide with the 1964 Tokyo Olympics, | 为了配合1964年东京奥运会 |
| 2 | Japan launched the world's first high-speed train, the Shinkansen. | 日本推出世界首列高速列车申坎森号. |
| 3 | Capable of running at 210 kilometers per hour, | 以每小时210公里的速度运行, |
| 4 | this groundbreaking bullet train inspired countries around the world | 这辆突破性子弹列车启发了世界各国 |
| 5 | to invest in high-speed rail. | 投资高速铁路. |
| 6 | Today, these trains regularly travel at over 300 kilometers per hour, | 今天,这些列车定期以每小时300公里的速度行驶, |
| 7 | on par with the takeoff speed of a commercial airplane. | 与商业飞机的起飞速度相当 |
| 8 | But could these trains go even faster, | 但是这些火车能开得更快吗? |
| 9 | whisking passengers to their destinations quicker than the smoothest flight? | 比最顺利的飞行快吗? |
| 10 | To answer this, it helps to understand how these trains reach | 为了回答这个问题,它有助于理解这些列车是如何到达的 |
| 11 | their already impressive speeds. | 他们已经令人印象深刻的速度。 |
| 12 | There are three main factors that separate bullet trains | 区分子弹列车有三个主要因素 |
| 13 | from traditional low-speed trains— | 从传统的低速列车... |
| 14 | engines, aerodynamics, and infrastructure. | 发动机、空气动力学和基础设施。 |
| 15 | Most traditional trains are powered by combustion engines, | 大多数传统列车由燃烧发动机供电, |
| 16 | which combust fuel, typically diesel, to turn an electric generator. | 燃烧的燃料,一般是柴油,用来转动发电机。 |
| 17 | This electricity is then used to power motors that turn the train's wheels. | 之后这种电力被用于为使列车轮子转动的电动机供电. |
| 18 | High-speed trains, on the other hand, use electric engines to power their motors. | 而高速列车则使用电动发动机为其发动机供电. |
| 19 | This process is more energy efficient than combustion | 这个过程比燃烧更节能 |
| 20 | and allows train operators to reach top speeds more quickly. | 并允许列车运营商更快达到最高速度. |
| 21 | Next up is aerodynamics. | 接下来是空气动力学 |
| 22 | While low- and high-speed trains use the same steel wheels | 低速和高速列车使用相同的钢轮 |
| 23 | to minimize friction with the track, | 尽量减少与赛道的摩擦, |
| 24 | bullet trains are also designed with aerodynamic bodies | 子弹列车也采用空气动力车体设计 |
| 25 | that slice through air with minimal resistance. | 以最小的阻力穿过空气 |
| 26 | Engineers could use these slicker designs on traditional train cars, | 工程师可以在传统的列车车厢上使用这些浮雕设计, |
| 27 | but while upgrading to electric engines would make low-speed trains more efficient, | 但是,虽然升级到电动发动机可以提高低速列车的效率, |
| 28 | they wouldn't get much benefit from these aerodynamic designs | 他们不会从这些空气动力设计中获得多少好处 |
| 29 | because of the third factor—infrastructure. | 因为第三个因素——基础设施。 |
| 30 | Traditional train tracks were built to meet people where they lived, | 传统的火车轨道是用来满足人们的居住, |
| 31 | ensuring stations were accessible to any potential passengers. | 确保任何潜在乘客都能进入车站。 |
| 32 | But to prevent derailments in these highly populated areas, | 但是为了防止这些人口密集地区的脱轨, |
| 33 | trains need to frequently decelerate to safely hit turns and crossroads. | 列车需要经常减速以安全地撞到转弯和十字路口. |
| 34 | High-speed rails, on the other hand, were built to prioritize speed. | 而高速铁路则以优先速度建设. |
| 35 | They run on long, straight lines that avoid road crossings, | 他们跑在长的直线 避免道路过关, |
| 36 | sharp curves, and high-traffic areas. | 尖锐的曲线,和高流量的区域。 |
| 37 | These three differences allow high-speed trains | 这三种区别允许高速列车 |
| 38 | to reach top speeds over double their traditional counterparts. | 达到最高速度 两倍于他们的传统对应。 |
| 39 | And since their infrastructure allows them to travel longer distances between stops, | 因为他们的基础设施 让他们可以走更长的路程 |
| 40 | they spend more time cruising near top speed, | 他们花更多的时间 在接近最高速度, |
| 41 | often traveling up to three times the average speed of traditional trains. | 经常乘坐最多为传统列车平均速度的三倍. |
| 42 | But new technology is emerging to make even faster trains. | 但新技术正在兴起,以制造更快的列车. |
| 43 | To eliminate friction between rails and wheels, | 为了消除铁路和车轮之间的摩擦, |
| 44 | engineers have developed new magnetic levitation, or maglev trains. | 工程师开发了新的磁悬浮,或称磁悬浮列车. |
| 45 | There are two major approaches here. | 这里有两种主要的方法。 |
| 46 | In electromagnetic suspension, magnetized arms wrap under the track and pull the train up. | 在电磁悬浮中,电磁化的手臂包裹在铁轨下,将列车拉上. |
| 47 | Meanwhile, in electrodynamic suspension, coils embedded in the track | 同时,在电动悬浮中, 嵌入轨道的线圈 |
| 48 | create a pattern of alternating magnetic fields | 创建交替磁场模式 |
| 49 | that interact with magnets on the train to float the vehicle a few centimeters in the air. | 与火车上的磁铁相互作用 将车辆浮在空中几厘米 |
| 50 | To change speed, train operators alternate the direction of the train's magnetic field, | 为了改变速度,列车运营商轮流选择列车磁场方向, |
| 51 | attracting the front of the train to the next coil to speed up, | 吸引列车前部进入下一个线圈加速, |
| 52 | or reversing the field's phase to brake. | 或扭转球场的阶段来制动。 |
| 53 | Given enough runway, these trains can reach speeds from 430 | 由于跑道足够长,这些列车从430可以达到速度 |
| 54 | to a theoretical 600 kilometers per hour, | 至理论600公里每小时, |
| 55 | allowing them to make the over 4,400-kilometer trip | 让他们能走4400公里的路 |
| 56 | from New York City to Los Angeles in as little as seven hours. | 7小时后从纽约市到洛杉矶 |
| 57 | So, why haven't we built maglev trains, or even high-speed trains, everywhere? | 那么,为什么我们没有建造 磁铁列车,甚至高速列车,任何地方? |
| 58 | First, these trains require lots of energy, | 首先,这些列车需要大量能量 |
| 59 | most of which is needed to overcome air resistance. | 大部分需要克服空气阻力 |
| 60 | In fact, at 300 kilometers per hour, | 事实上,以每小时300公里的速度 |
| 61 | this task accounts for over 80% of a train's energy consumption. | 这项任务占火车能耗的80%以上。 |
| 62 | Engineers are researching ways to reduce air resistance, | 工程师们正在研究减少空气阻力的方法, |
| 63 | such as putting maglevs in near-vacuum environments. | 比如在接近真空的环境中放置岩浆。 |
| 64 | But building a vacuum-sealed tunnel across an entire country | 但是,建造一个真空密封的隧道 跨越整个国家 |
| 65 | would be an infrastructure project of science-fictional proportions. | 这将是一个具有科幻规模的基础设施项目。 |
| 66 | Besides, it's hard enough to build regular high-speed rails. | 此外,建设常规高速铁路也十分困难. |
| 67 | To go fast, trains need long, straight tracks with wide curves, | 要快速行驶,列车需要长而直的有宽曲线的轨道, |
| 68 | which are very difficult to build in mountains, cities, or densely populated areas. | 在山地、城市或人口稠密地区建设起来非常困难。 |
| 69 | Building such routes is costly, politically sensitive, | 建造这样的路线代价高昂,政治敏感, |
| 70 | and often physically impossible. | 并且经常是身体上不可能。 |
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