Math & Science ⇒ hyperref and equation positioning

[applewife]

I am using the "hyperref" package in my thesis. Now everything is working except for a problem. When I clicked the referred equation number, it is supposed to locate the equation. However, in my case, it jumps to the position where the bottom position of the equation is. In other words, I need to scroll the computer screen down a little to see the equation.

Could anyone help me to solve this problem? It is very urgent because I need submit my thesis today! Thank you in advance!