This background has a gradient applied to it.
背景应用有渐变。
Draw a rectangle with a subtle blue gradient at the bottom of the post container.
在内容区域底部画一个浅色矩形。
If you have a gradient field then it should have this property.
如果给定一个梯度场，那么它就应该满足这个性质。
Now it should be a gradient field.
那么它应该就是一个梯度场。
Well, the gradient is also a way to package partials together.
同样地，梯度也是把偏导数糅合到一起。
The problem is not every vector field is a gradient.
问题是，不是所有向量场都是梯度。
When I am at a minimum, the two gradient vectors are parallel.
当在最小值点的时候，两个梯度向量就垂直了。
If you are a physicist, that the force will be negative the gradient.
如果你是物理学家，力其实是负的梯度。
为什么要说F是一个梯度场？
Yes? How do I know the direction of a gradient?
我怎样知道梯度的方向？
So, indeed, this is not a gradient field.
因此这不是一个梯度场。
We have said if we have a gradient field then we have this.
如果有一个梯度场，那就能得到这个。
Yes? How do you determine whether something is a gradient or not?
怎样确定一个场是不是梯度？
Well, you take the gradient of a function.
作出一个函数的梯度。
You know it's a gradient, f and you know the function, little f.
如果知道一个梯度，相应地就有一个函数。
也就是梯度场。
The question is for which value of a is this a gradient?
问题是a取多少时，这是一个梯度场？
It is a gradient field. We need three conditions.
这是一个有势场，我们需要三个条件。
So, in particular, only if you have a conservative field, a gradient field.
特别地，仅当是保守场，即有势场时才可以使用。
Now we are going to create a sky gradient for the top of the canvas.
现在，我们要为画布顶端创建一个天空蓝色渐变。
An image is used in the background to provide a gradient to white.
在背景中使用一个图像提供到白色的逐变。
"It's not rich versus poor, because it's a social gradient," he says.
他说：“这不是富对穷的问题，这是社会关注倾向在哪。”
The main difference is the addition of a gradient to give it a fresher aesthetic.
主要变化是增加了色彩渐变，使得视觉上更加美观。
它不是梯度。
And that means also it's a gradient field. It's the same thing.
这意味着，F是个梯度场，这是一样的。
Say that it is a gradient field.
如果F是梯度场。
So how do we get a gradient background on a shell?
那么如何在shell上得到渐变的背景色呢？
The car can also easily climb a gradient of 23% at take-off.
汽车也可以轻易爬梯度的23%，起飞。
The second is a light gradient under the roofing.
其次是屋顶下方的一个小坡度。
The second is a light gradient under the roofing.
其次是屋顶下方的一个小坡度。
应用推荐