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For a decade, metallurgists studying the hulk of the Titanic have argued that the storied ocean liner went down quickly after hitting an iceberg because the ship's builder used substandard rivets that popped their heads and let tons of icy seawater rush in. More than 1,500 people died.
Now a team of scientists has moved into deeper waters, uncovering evidence in the builder's own archives of a deadly mix of great ambition and use of low-quality iron that doomed the ship, which sank 96 years ago Tuesday.
The scientists found that the ship's builder, Harland and Wolff, in Belfast, struggled for years to obtain adequate supplies of rivets and riveters to build the world's three biggest ships at once: the Titanic and two sisters, Olympic and Britannic.
Each required three million rivets, and shortages peaked during Titanic's construction.
"The board was in crisis mode," said Jennifer Hooper McCarty, a member of the team that studied the company's archive and other evidence. "It was constant stress. Every meeting it was, 'There's problems with the rivets, and we need to hire more people.' "
The team collected other clues from 48 Titanic rivets, using modern tests, computer simulations, comparisons to century-old metals and careful documentation of what engineers and shipbuilders of the era considered state of the art.
The scientists say the troubles began when the colossal plans forced Harland and Wolff to reach beyond its usual suppliers of rivet iron and include smaller forges, as disclosed in company and British government papers. Small forges tended to have less skill and experience.
Adding to the threat, the company, in buying iron for Titanic's rivets, ordered No. 3 bar, known as "best," not No. 4, known as "best-best," the scientists found. They also discovered that shipbuilders of the day typically used No. 4 iron for anchors, chains and rivets.
So the liner, whose name was meant to be synonymous with opulence, in at least one instance relied on cheap materials.
The scientists argue that better rivets would have probably kept the Titanic afloat long enough for rescuers to have arrived before the icy plunge, saving hundreds of lives.
正確答案:1996年,一位攝影師在新疆喀納斯自然保護區(qū)無意間拍到一只白熊。自此以后的十年里,白熊藏身于深山之中,再無音訊。直到2003年,人們才再次在該自然區(qū)又發(fā)現(xiàn)了白熊的蹤跡。
在熊的家族里,只有北極熊是白色的。但是,這個龐然大物是如何離開極地寒帶,來到這個寒溫帶的地方呢?難道它是通過通往北極的水路來到此地?這一猜測遭到動物學家的質(zhì)疑。首先,北極熊不能在溫帶的樹林中生活。其次,。。。。。。。。。
2006年,一個科學考察隊在白熊出沒的地區(qū)發(fā)現(xiàn)了熊冬眠的冬窩兒,還發(fā)現(xiàn)了一小團白色的動物毛發(fā)。DNA樣本鑒定為棕熊的毛發(fā)。但是,也有可能,至少那團毛發(fā)不屬于照片中的白熊.
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