These coils are normally used to select slices for creating three-dimensional images, but the magnetic fields they create can also be used to exert a force on a small magnetic object inside a scanner.

这些线圈通常用于选择建立三维图像的切片，但是它们所建立的磁场也能被用来在扫描仪内部的小磁性物体上施加作用。

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So the use of military force will remain a matter largely for those willing and able to exert it.

所以武力解决对于那些有能力并愿意实施的国家来说仍然不愧为首选。

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Their trick was to shorten the lengths of the pulses of current to about a nanosecond. Rapidly changing currents exert a greater force on domain walls than do slowly changing ones.

他们的秘诀就在于将一阵阵电流的长度缩短到纳秒，因为与缓慢转变电流相比，快速地改变电流在域壁上产生的力度要来得更大。

youdao

It says, if you pull it to the right, so that x is positive, the spring will exert a force which is in the negative direction; that's why you have a minus sign.

就是说,如果你向右拉,x 取正值,弹簧产生的力方向为负,这就是这里用负号的原因

耶鲁公开课 - 基础物理课程节选

In fact, Bejan and his colleagues found that interactions between the hand and the water when the fingers are slightly spread increase the total force a swimmer can exert, translating to faster times in the pool.

MSN: Fastest swimmers make webbed hands out of water

Since a bestselling book published in 1983 argued that freemasons exert a malign influence in public life, people have tried to force freemasons to declare themselves.

ECONOMIST: Freemasonry