首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
The oceans, which cover nearly three-quarters of Earth’s surface, remain largely unexplored because of their vastness and inacce
The oceans, which cover nearly three-quarters of Earth’s surface, remain largely unexplored because of their vastness and inacce
admin
2010-07-24
50
问题
The oceans, which cover nearly three-quarters of Earth’s surface, remain largely unexplored because of their vastness and inaccessibility to us air breathers. Webb Research of East Falmouth, Massachusetts, hopes to open up much of that mystery field with a new underwater vehicle that is pushed ahead solely by the ocean itself, so it can potentially study the watery depths for years at a time. Such long-lasting detectors may someday form fleets that provide up-to-minute data for weather forecasting.
In the past, such autonomous underwater vehicles, or AUVs, have been battery powered and therefore required frequent recharges that limited their distance and depth of travel. Webb’s Slocum glider(滑翔机) hopes to solve this problem. "We conceived of a thermally powered engine to get the energy from the colder deep water of the ocean and the shallower warm water," Clayton Jones, an engineer at Webb Research, explains. "We picked out a material that undergoes a state change between those two temperatures in the ocean." When cold, this form-shifting substance is a compact solid. When warm, it expands and becomes a less dense liquid. The material’s expansion in warmer waters charges an internal mechanism that acts like stored power to control its buoyancy: by pumping mineral oil in and out of an external air bag, it alters its volume but maintains its weight. "The glider takes up more volume and becomes lighter than the water around it--less dense," Jones says.
Scientists can also fit the Slocum glider with a variety of different sensory equipment and Global Positioning Systems. Each time it surfaces, it can raise its tail antenna(天线) to transmit data to and receive instructions from researchers sitting comfortably in their cozy offices. The glider will have its first test in salt water at the end of this September.
The gliders could also get through and follow previously unstudied phenomena such as small underwater eddies (漩涡), which are vital to understanding water transport and heat flow in the ocean and therefore play an important role in storm formation and other weather development. "We have all these data snapshots(快照) from floats that just flow with the deep ocean current," Jones says. "To be able to fly through eddy sections, then transport with the whole eddy itself as it moves through the ocean, would be a very nice phenomenon to take a look at."
The disadvantage of traditional underwater vehicles is their ______.
选项
A、inferior designs
B、poor quality
C、limited power supply
D、water resistant ability
答案
C
解析
由题干中的The disadvantage of traditional underwater vehicles定位到原文第二段首句“In the past,such autonomous underwater vehicles…limited their distance and depth of travel.”。
转载请注明原文地址:https://kaotiyun.com/show/7bN7777K
0
大学英语四级
相关试题推荐
Wantaglimpseofthefutureofhealthcare?Takealookatthewaythevariousnetworksofpeopleinvolvedinpatientcareare
A、Aneconomicalwayoftravelingfortheyoung.B、Importanceofphysicaltrainingtostudents.C、Effectsofindustrializationon
DoctorsinBritainarewarningofanobesitytimebomb,whenchildrenwhoarealreadyoverweightgrowup.So,whatshouldwedo?
DepartingforLosAngelesisnoordinary【C1】______whereasforforeignstudentswhoarestartinganewexperiencelivingonthe
OurformerforeignteacherwasayoungmanwhocamefromEngland.Hewasa【B1】______personwhodidnottalkmuchtostrangers,
OurformerforeignteacherwasayoungmanwhocamefromEngland.Hewasa【B1】______personwhodidnottalkmuchtostrangers,
OurformerforeignteacherwasayoungmanwhocamefromEngland.Hewasa【B1】______personwhodidnottalkmuchtostrangers,
Mostparents,Isuppose,havehadtheexperienceofreadingabedtimestorytotheirchildren.Andtheymusthave【C1】______how
A、Satisfied.B、Interested.C、Tired.D、Discouraged.D
A、Shehasapart-timejob.B、Shereceivedascholarship.C、Herparentspayforit.D、Sheisworkingasatouristguide.B
随机试题
根据支付结算法律制度的规定,下列票据中,允许个人使用的有()。
简述法律责任的特点。
CSF中需要用墨汁染色检验的细菌是
高级管理人员包括公司的财务负责人、上市公司董事会秘书、经理等,但不包括公司的副经理。()
收入差距的衡量指标是()。
据统计,2016年共有来自205个国家和地区的442773名各类外国留学人员在31个省、自治区、直辖市的829所高等学校、科研院所和其他教学机构中学习,比2015年增加45138人。1.按洲别统计2.按国别排序前15名:韩国70540人,美国2383
第6题程序中,若代码CSEG1占用的内存空间是13AD0H~13AE4H,则代码段CSEG2在内存中的起始地址是______H。
過疎化の進んだ村では高齢者ばかりが目立つようになりましたが、村に活気を取り戻すために工場を誘致したり、観光客を呼び寄せています。過疎化
Ifpeoplegowithoutamealallday,theybegintofeellikethis.h______
ButsomebookswouldcostmoremanIhave.ButIdidn’t______tobuysomebooks.
最新回复
(
0
)