The directional derivative in a direction that's perpendicular to the gradient is basically zero.
垂直于梯度的方向上,方向导数为零。
OK, so, we've seen that if we have a vector field defined in a simply connected region, and its curl is zero, then it's a gradient field, and the line integral is path independent.
一个向量场,如果定义在单连通区域并且旋度为零，那么它就是一个梯度场，并且其上的线积分与路径无关。
Well, we've seen this criterion that if a curl of the vector field is zero and it's defined in the entire plane, then the vector field is conservative, and it's a gradient field.
我们已经知道了一个准则，如果向量场的旋度为零，而且它在整个平面上有定义，那么这个向量场是保守的，而且它是个梯度场。
The increasing rates of pressure gradient of two sides of outburst coal decrease with the increase of gas pressure and reach to zero at last.
随着瓦斯压力的增加，突出煤样两端的瓦斯压力梯度增大率会逐渐减小，最终趋近于零。
So-called gravity anomaly linear structure signal is derivative of gravity anomaly level total gradient on gravity direction, and the derivatives must be greater than zero.
所谓重力异常线性构造信号就是重力异常水平总梯度沿重力方向的一阶导数且是大于零值的那一部分。
So-called gravity anomaly linear structure signal is derivative of gravity anomaly level total gradient on gravity direction, and the derivatives must be greater than zero.
所谓重力异常线性构造信号就是重力异常水平总梯度沿重力方向的一阶导数且是大于零值的那一部分。
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