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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 above 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 composites. 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 possible
A.
It swims.
B.
It raises its nose.
C.
It uses hydrojets.
D.
It uses its four-wheel drived.
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【多选题】根据态度和技巧,倾听可分为七个层次。从低到高依次为:佯装倾听,(),第一印象,尊重,(),激励和把握别人的倾听投入程度。
A.
把握
B.
控制
C.
理解
D.
换位思考
【简答题】● 在面向对象技术中,(38)说明一个对象具有多种形态,(39)定义超类与子类之间的关系。 (38)A.继承 B.组合 C.封装 D.多态 (39)A.继承 B.组合 C.封装 D.多态
【单选题】在面向对象技术中,(38)说明一个对象具有多种形态。
A.
继承
B.
组合
C.
封装
D.
多态
【简答题】根据昼夜长短的纬度分布规律,按“5.1”节的昼长,将下列各地排列序次(从长到短);北京(40°N)、上海(31°N)、哈尔滨(45°N)、新加坡(1°N)、雅加达(1°S)、墨尔本(37°S)和开普敦(34°S)。
【单选题】一个竖直向上运动的小球,运动过程中只受重力和空气阻力的作用.则小球所受的合力 ( )
A.
一定小于重力
B.
一定大于重力
C.
一定等于重力
D.
以上说法均不正确
【单选题】从离地面高度相同的同一点,同时以大小相同的速度,水平和竖直向上抛出两个质量相同的小球,运动过程中只受重力。下列说法中正确的是()
A.
两个小球在空中的运动时间相同
B.
两个小球落地时的速度相同
C.
两个小球在空中的运动过程中,合外力做功相同
D.
两个小球落地时的重力做功的功率相同
【单选题】下列说法正确的是()
A.
运动越快的汽车越不容易停下来,是因为汽车运动得越快,惯性越大
B.
同一物体在地球上不同的位置受到的重力是不同,所以它的惯性也随位置的变化而变化
C.
一个小球竖直上抛,抛出后能继续上升,是因为小球运动过程中受到了向上的推力
D.
物体的惯性大小只与本身的质量有关,质量大的物体惯性大,质量小的物体惯性小
【简答题】●在面向对象技术中,(38)说明一个对象具有多种形态,(39)定义超类与子类之间的关系。 (38)A.继承 B.组合 C.封装 D.多态 (39)A.继承 B.组合 C.封装 D.多态
【单选题】下列说法正确的是()
A.
运动越快的汽车越不容易停下来,是因为汽车运动得越快,惯性越大
B.
同一物体在地球上不同的位置受到的重力是不同的,所以它的惯性也随位置的变化而变化
C.
一个小球竖直上抛,抛出后能继续上升,是因为小球运动过程中受到了向上的推力
D.
物体的惯性大小只与本身的质量有关,质量大的物体惯性大,质量小的物体惯性小
【单选题】在面向对象技术中, (38) 说明一个对象具有多种形态, 继承 定义超类与子类的关系。
A.
继承
B.
组合
C.
封装
D.
多态
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