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
113
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 power of the new AUV is stored in the ______.
选项
A、form-shifting substance
B、internal mechanism
C、spring that is pushed into a tight coil
D、external bladder
答案
B
解析
由题干定位到原文第二段第三句“We conceived of a thermally powered engine…and the shallower warm water.”。
转载请注明原文地址:https://kaotiyun.com/show/KbN7777K
0
大学英语四级
相关试题推荐
A、Nearly7million.B、Nearly17million.C、Nearly70million.D、Nearly77million.C
A、Becauseindustrializationhaddamagedthebeautiesofthecountryside.B、Becausethewoodsandfieldsweretoofarawaytobe
A、Shemadegoodtips.B、Shewasfinedbecauseshedrovedesperately.C、Shehitapoleandwasfiredagain.D、Herpassengerwasb
A、Becauseshemissedthatclass.B、Becauseshedidn’tcopydowntheassignmenteither.C、Becauseshedidn’twantthemantocopy
DoctorsinBritainarewarningofanobesitytimebomb,whenchildrenwhoarealreadyoverweightgrowup.So,whatshouldwedo?
OurformerforeignteacherwasayoungmanwhocamefromEngland.Hewasa【B1】______personwhodidnottalkmuchtostrangers,
Mostparents,Isuppose,havehadtheexperienceofreadingabedtimestorytotheirchildren.Andtheymusthave【C1】______how
Mostparents,Isuppose,havehadtheexperienceofreadingabedtimestorytotheirchildren.Andtheymusthave【C1】______how
IfirstmetBilliewhenIcametoNewYorkat19.Ididn’tknowwhatIwasgoingtobe.Iwantedtobeblack,soI【B1】______out
IfirstmetBilliewhenIcametoNewYorkat19.Ididn’tknowwhatIwasgoingtobe.Iwantedtobeblack,soI【B1】______out
随机试题
有以下公式:若已经正确引用math.h文件,下列不能正确计算上述公式的程序段是【】
作为一门独立学科的艺术学诞生于______。()
丹参可应用于()
病人,女,75岁,高血压病30余年,平日血压控制在140/90mmHg,糖尿病4年,应用降糖药物控制血糖。近半年来常于劳累时感心前区闷痛,持续1~2分钟,休息后缓解,未予诊治。4小时前突感胃疼伴烧心感,伴大汗,恶心呕吐1次,呕吐物为胃内容物。急诊入院。查:
甲房地产咨询公司(以下简称甲公司)设立于1998年,购买了位于某居住区配套的商业用房作为经营用房,注册资本为200万元。甲公司根据相关法律按税后利润的10%提取法定公积金,至2008年年底累积提取100万元,2009年甲公司税后利润为120万元,当年分配7
量子数n=4,l=2,m=0的原子轨道数目是:
“会计电算化”一词始于()。
某外商投资企业2005年度发生如下经济事项:(1)2005年4月,签订销售合同一份,金额50万元。(2)2005年11月,审查后发现记载资金的账户比期初多出100万元,其中包括应拨付给外地分支机构的资金30万元。(3)2005年12月,按规定到有关部
《物业管理条例》对前期物业管理招投标作了例外的规定。对于投标人少于()个的,可以采用协议的方式选聘物业管理企业。
A、10:30pm.B、11:00pm.C、11:30pm.D、12:00pm.D男士说,餐馆周末的营业时间一直到午夜,即12:00pm,故答案是D。关键是分辨weekdays和weekend的不同营业时间,做笔记时要迅速和完整地记下细节
最新回复
(
0
)