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【单选题】
It looks as if it came straight from the set of Star Wars. It has four-wheel drive and rises a bove rocky surfaces. It lowers and raises its nose when going Up and down hills. And when it comes to a river, it turns amphibious two hydro jets power it along by blasting water under its body. There is room for two passengers and a driver, who sit inside a glass bubble operating electronic, aircraft-type controls. A vehicle so daring on land and water needs windscreen wipers -- but it doesn't have any. Water molecules are disintegrated on the screen's surface by ultrasonic sensors. This unusual vehicle is the Racoon. It is an invention not of Hollywood but of Renault, a rather conservative French state-owned carmaker, better known for its family hatchbacks. Renault built the Racoon to explore new freedoms for designers and engineers created by advances in materials and manufacturing processes. Renault is thinking about startlingly different cars other producers have radical new ideas for trains, boats and aeroplanes. The first of the new freedoms is in design. Powerful computer-aided design (CAD) systems can replace with a click of a computer mouse hours of laborious work done on thousands of drawing boards. So new products, no matter how complicated, can be developed much faster. For the first time, Boeing will not have to build a giant replica of its new airliner, the 777, to make sure all the bits fit together. Its CAD system will take care of that. But Renault is taking CAD further. It claims the Racoon is the world's first vehicle to be designed within the digitised world of virtual reality. Complex programs were used to simulate the vehicle and the terrain that it was expected to cross. This allowed a team led by Patrick Le Quement, Renault's industrial-design director, to 'drive' it long before a prototype existed. Renault is not alone in thinking that virtual reality will transform. automotive design. In Detroit, Ford is also investigating its potential. Jack Telnac, the firm's head of design, would like designers in different parts of the world to work more closely together, linked by computers. They would do more than style. cars. Virtual reality will allow engineers to peer inside the working parts of a vehicle. Designers will watch bearings move, oil flow, gears mesh and hydraulics pump. As these techniques catch on, even stranger vehicles are likely to come along. Transforming these creations from virtual reality to actual reality will also become easier, especially with advances in materials. Firms that once bashed everything out of steel now find that new alloys or composite materials (which can be made from mixtures of plastic, resin, ceramics and metals, reinforced with fibers such as glass or carbon) are changing the rules of manufacturing. At the same time, old materials keep getting better, as their producers try to secure their place in the factory of the future. This competition is increasing the pace of development of all materials. One company in this field scaled composites. It was started in 1982 by Burt Rutan, an aviator who has devised many unusual aircraft. His company develops and tests prototypes that have ranged from business aircraft to air racers. It has also worked on composite sails for the America's Cup yacht race and on General Motors' Ultralite, a 100-miles-per-gallon experimental family car built from carbon fiber. Again, the Racoon reflects this race between the old and the new. It uses conventional steel and what Renault describes as a new 'high-limit elastic steel' in its chassis. This steel is 30% lighter than the usual kind. The Racoon also has parts made from compostites. Renault plans to replace the petrol engine with a small gas turbine, which could be made from heat-resisting ceramics, and use it to run a generator that would provide power for electric motors at each wheel. With composites it is possibl
A.
It swims.
B.
It raises its nose.
C.
It uses hydrojets.
D.
It uses its four-wheel drive.
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【单选题】CNKI中国知网首页的搜索框支持"or"、"and"等组成的布尔逻辑检索式吗?( )
A.
支持
B.
不支持
【判断题】态度不是行为而是行为倾向。()
A.
正确
B.
错误
【多选题】关于曲线,下列说法正确的是
A.
曲线如果是默认的通过原点的45度斜直线,那么该图像输入输出没有任何变化,相当于该图像没有做调整
B.
曲线面板可以针对图像的某一个单一通道进行调整
C.
曲线中的锚点可以根据自己的需要加无数个
D.
曲线的形状可以根据需要更改,还可以添加锚点
【单选题】课本中的图表、数据等可以提供很多信息。下面有关的说法不正确的是
A.
根据某元素的原子结构示意图可判断该元素原子核内中子的数目
B.
“酸、碱、盐的溶解性表”是判断复分解反应能否发生的依据之一
C.
根据相对分子质量可比较气体的密度大小
D.
根据不同物质的溶解度曲线图,可确定混合溶液的分离方法
【多选题】根据图中曲线,下面说法正确的是:
A.
理论空燃比附近,三种有害气体的转换效率最高
B.
混合气越稀,NOx化合物转化效率越低
C.
混合气越浓,NOx化合物转化效率越低
D.
混合气越浓,CH,CO转化效率越低
【单选题】课本中的图表、数据等可以提供很多信息。下面有关的说法 不正确的是 [     ]
A.
根据相对分子质量可比较气体的密度大小
B.
根据某元素的原子结构示意图可判断该元素原子核内中子的数目
C.
“酸、碱和盐溶解性表”是判断复分解反应能否发生的依据之一 D. 根据不同物质的溶解度曲线图,可确定混合溶液的分离方法
【简答题】地球本身就是一个巨大的磁体.水平放置、能自由转动的小磁针之所以在地球表面指向南北,就是因为受到______的影响.最早发现地磁两极与地理两极并不重合的科学家是我国宋代的______.
【判断题】中国古典舞受太极哲学、阴阳学说的文化影响,以错位、交叉为特点。
A.
正确
B.
错误
【单选题】下面关于矢量图的说法中,不正确的是:( )
A.
矢量图由矢量定义的直线和曲线组成,根据轮廓的几何特性进行描述。
B.
矢量图适合表现各种图形
C.
矢量图由矢量绘图的程序生成
D.
矢量图充分放大时不会造成失真
【单选题】()是指储蓄的增量和收入的增量之比率。
A.
边际消费倾向
B.
边际储蓄倾向
C.
平均消费倾向
D.
平均储蓄倾向
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