It's a direction sign.

它是一个指方向的标志。

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Photo 281: Direction sign at existence of theme pavilion.

图281：主题馆出口处的标识，宝宝很可爱。

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The pointed direction sign is sited at the junction and marks the turn.

在路口设置的箭咀形方向标志，指示转弯可往所述的地方。

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Infinity is the force when we're thinking about it and our brains, negative infinity is when we actually plug it into the equation here, and the reason is the convention that the negative sign is just telling us the direction that the force is coming together instead of pushing apart.

说力有多大时，我们想到的,是无穷大，而方程解出来的,是负无穷，这是因为习惯上,我们用负号表示力的方向,是相互吸引而不是相互排斥的,所以我们可以用库仑定律。

麻省理工公开课 - 化学原理课程节选

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 my room, a sign indicating the direction of prayer was posted over the nonalcoholic minibar.

NEWYORKER: The Sanctuary

What they do in the primaries will be a sign of their direction in November especially in a big swing state like Ohio.

NPR: Catholics a Key Voting Bloc in Ohio

There was no sign of land in any direction.

NEWYORKER: Max at Sea