亚博APP买球信誉靠谱|10大新发明? 错!其实都是老发明!(上)

Self-driving cars, selfie sticks, drones, touchscreen devices, e-cigarettes, jetpacks, and many other things seem like fairly modern inventions. Indeed, most of their inventors list them as newly invented and even go as far as seeking patents. But the fact is, many of these inventions have already been in existence for quite some time. They may have earlier lookalikes that ended up not going into production or that went into limited production due to one reason or another. Some also made it into full production but were recalled due to poor sales.自动驾驶汽车,自拍杆,无人驾驶飞机,触屏设备,电子香烟,喷气背包和许多其他看上去像现代的发明者的东西,只不过都是杨家发明者。 继续阅读

亚博APP安全有保障:双语科技百科(物理) 第38期:杆秤

Chinese Steelyard-Gancheng杆秤The steelyard is a Chinese invention.As early as 200 B.C.,China be-gan to make a scale of this type big enough to weigh several hundred pounds. The steelyard consisted of the following parts: an arm, a hook, lifting cords and a weight.The arm or beam measured about l.5 metres long, graduat-ed with the weight units- jin and liang*. The hook, hanging from one end of the arm, was used to lift up the object to be weighed. Hanging from the other part of the arm was the freemoving weight, attached on a looped string. On the arm was fixed one, two or three lifting cords, placed much closer to the hook than to the other end. Anything to be weighed should be picked up by the hook, while the weigher lifted up the whole steelyard, holding one of the cords.He then slided the weight left or right until he found a perfect balance of the beam. He then read the weight from the graduation mark on which the weight-string rested.杆秤是中国发明者的历史最历史悠久的一种衡器。 继续阅读