The great difficulties are that it is rather hard to make such a sine wave inverter as that small as a normalsquare wave or corrected sine wave auto inverter.
车载逆变器输出正弦波的难点在于，无论是体积还是效率都很难和方波或修正正弦波逆变器媲美。
2
We're now scaling up to make cells that will be hundreds of square centimeters-the size of a normal cell.
我们现在正在增加它们的尺寸以使它们达到几百平方厘米——这是正常电池的尺寸大小。
3
One is that a normal distribution falls off according to the negative exponential of the square of the distance from the mean.