亚洲免费av电影一区二区三区,日韩爱爱视频,51精品视频一区二区三区,91视频爱爱,日韩欧美在线播放视频,中文字幕少妇AV,亚洲电影中文字幕,久久久久亚洲av成人网址,久久综合视频网站,国产在线不卡免费播放

        ?

        Build the Drone of Your Dreams

        2017-11-04 21:13:53
        中學(xué)科技 2017年10期

        Drones zoom around almost everywhere these days. Farmers use them to monitor crops. Scientists use them to study hostile places, such as the inside of a volcano. Others fly them as a hobby. But drones of the future may not look like todays models. But how well will such novel vehicles perform? Engineers at the Massachusetts Institute of Technology, in Cambridge, have created a new computer program that lets users design their own flying machines — and then pretest them.

        Many personal drones are some style of multicopter — a flying machine with spinning propellers. Quadcopters have four. Hexacopters have six. Yet “there are plenty of cases in which standard quadcopters and hexacopters might not be the best solution for a given task,” notes Tao Du. “There are only a small range of options for drones that you can buy,”points out this MIT graduate student who worked on the new program.

        The system from Dus team is the ultimate in do-it-yourself. It lets people pick the size, shape and structure that best fits their needs. Such an approach increases the shapes, styles and sizes of drones that users can fly and what they can do with them. And the designers dont need to be experts in physics to do it.

        Multicopters use their propellers to turn or go up and down. But the ones available to consumers cant fit every need. For example, a scientist who wants to attach a special camera may find that the drones propellers block its view. Or, a drone might need to carry an object with an irregular shape. Say, for instance, you want a drone to carry an egg. With an off-the-shelf model, youd have to rig up something that might destabilize it and cause it to crash. But if you design your own, you can build an egg carrier and choose a design that will keep it stable.

        The MIT system could help in such situations. As they design a custom machine that actually flies, DIYers must consider a number of questions. What happens when many propellers spin at once? How many parts can you add and still keep a drone lightweight enough to fly well? How much propeller power does the machine need to overcome gravity?

        1. Which of the following is similar in meaning to hostile in the underlined sentence? ____.

        A. deep B. unfavorable

        C. untapped D. faraway

        2. What is the major contribution by MIT engineers? ____.

        A. They have made a major breakthrough in making drones

        B. They have designed a novel drone

        C. They have created a computer system that can be used to produce standard drones

        D. They have created a program enabling users to design drones for specific purposes

        3. An off-the-shelf model in Paragraph 4 refers to ____.

        A. a drone that can be customized for its size, shape and structure

        B. a DIY system recently developed by MIT graduate students

        C. a standard flying machine with spinning propellers

        D. an egg carrier with customized designs to address the problem of irregular shape

        4. Gravity in the last paragraph refers to ____.

        A. a force that causes drones to turn or go up and down

        B. a driving force provided by propellers

        C. a powerful force caused by a volcano

        D. a force that causes objects to fall or to be attracted to the groundendprint

        成人av毛片免费大全| 欧美日韩精品乱国产538| 亚洲精品一区网站在线观看| 99国语激情对白在线观看| 国产自拍高清在线观看| 中文字幕人妻被公上司喝醉| 欧美一欧美一区二三区性| 国产在线观看不卡网址| 国产嫩草av一区二区三区| 欧美成人精品午夜免费影视| 国产在视频线精品视频www666| 蜜桃在线一区二区三区| 美女在线一区二区三区视频| 日本一卡2卡3卡4卡无卡免费网站| 99re这里只有热视频| 日本岛国一区二区三区| 公厕偷拍一区二区三区四区五区| 久久久久亚洲精品中文字幕| YW亚洲AV无码乱码在线观看| 精品中文字幕久久久人妻| 极品美女扒开粉嫩小泬图片| 亚洲欧洲无码av不卡在线 | 精品三级国产一区二区三| 久久香蕉国产线看观看精品yw| 亚洲成人电影在线观看精品国产| 亚洲一区二区三区乱码在线| 亚洲国产成人av二区| 少妇无码av无码专区线| 亚洲精品国产老熟女久久| 亚洲熟妇一区二区蜜桃在线观看| 中文字幕一精品亚洲无线一区| 四月婷婷丁香七月色综合高清国产裸聊在线 | 中文字幕精品一区二区日本| 自拍偷自拍亚洲精品第按摩| 无遮无挡爽爽免费毛片| 亚洲 无码 制服 丝袜 自拍| 日本av一级视频在线观看| 亚洲av无码久久| 国产毛片视频网站| 亚洲大胆视频在线观看| 高潮毛片无遮挡高清视频播放|