If you take a vector field that is a constant vector field where everything just translates then there is no divergence involved because the derivatives will be zero.

如果取的向量场是处处恒定的，所有点都是平移关系，所以没有散度，因为导数为零。

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Previous experiments have shown that applying a constant electric field created small effects on flames, but Cademartiri's work used an oscillating electric field to greater effect.

过去的实验已证实，施加恒定电场于火焰上会产生较小的效应，而Cademartiri在工作中采用振荡电场得到了更显著的效应。

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The second piece of luck is that all over the Earth there is a constant vertical electrical field.

第二个比较幸运的地方是，遍布全世界的范围内都有一个恒定的垂直磁场。

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At that age, teammates play all the positions, and Martin, with a near-constant grin, was happy anywhere on the field, Mr. Calderon said.

WSJ: In Boston Neighborhood, Shock at Death of 8-Year-Old

Polanski used the dour north coast of Germany as a substitute for the Vineyard in winter, and the cinematographer Pawel Edelman turns the constant downpour and gloom into a beautiful, slate-colored curtain a subdued but enveloping field of lies and secrecy, impenetrable to the Ghost, who is lost among power players far too clever for him.

NEWYORKER: The Ghost Writer