惨~记不全了,不过是一只从没见过的狗,所以放上来
一个单词不认识,不过看文章内容应该讲的是“共振”。
第一段讲共振的原理,主要是说桥,说什么频率一样的时候就容易塌,还举了个例子说在歌剧院,singer能把玻璃杯子给唱爆。
第二段讲应用在一些城市建设中urban。(是城市哦!)这里有题,问应用的。一个选项是只能用在桥上,一个是只能用在urban,其他三个都是无关选项吧
就记得这么多了。
文章不长,题目也简单。
google了下,不是这个,但是相似度挺大
Every rigid object in existence has a natural
structural resonance frequency, a frequency at which it, metaphorically speaking, wants to shake more than any other. If you vibrate an object at its resonant frequency, it will gradually shake more and more wildly, like a child on each swing being pushed higher and higher on each swing, until eventually it shakes itself to pieces. This is how you can shatter a wineglass at a distance by singing the right note - though you have to hold the note for several seconds so that the vibrations build up, and you have to sing superhumanly loudly, or else have your voice amplified.
The resonant frequency of an object depends on its structure. The larger the object, generally, the lower that frequency is. For things as large as buildings, architects have to design them so that normal use of the building, and natural weather conditions (wind/rain), can never combine to shake the building at one of its resonant frequencies. Failure to do this has proven hazardous in the past. In 2000, the London
Millennium Footbridge was found to sway unnervingly in time with people's footsteps when many people walked across it - it had to be closed and redesigned. Going back further, in 1850 the
Angers Bridge in France was shaken to pieces when 400+ soldiers marched across it in lockstep. Lessons well learned. Some very tall structures in earthquake zones are now built with
tuned mass dampers at the top, to cancel out such resonance.
(Conspicuously absent from these examples is the
Tacoma Narrows Bridge collapse. The Tacoma Narrows Bridge wasn't, strictly speaking, demolished by forced structural resonance, because there was no periodic disturbance on any of its natural vibrational modes - just constant wind. Rather, aerodynamic effects caused the road surface to act not unlike an aeroplane's wing, twisting on its axis and repeatedly catching the wind, then stalling and falling.)
From here we move a little way into the realm of urban legend. Famed physicist
Nikola Tesla is purported to have once created a small, pneumatic device which would automatically and mechanically seek out the structural resonance frequency of any solid object to which it was attached. Supposedly, he once took this device to a building site and attached it to the girderwork of a half-started building, causing it (after some minutes) to start vibrating so alarmingly that the builders abandoned it, fearing an earthquake. Tesla never used the machine again, out of fear. For the Earth is solid. The Earth has a structural resonance frequency. Could not his "earthquake machine" - which, let's be serious here, is
probably fictitious - be used to vibrate the Earth to pieces?
原文只有两段,貌似是前两段的合并