But it would take a telescope with the effective diameter of the sun to actually take photographs of something the size of an elephant strolling on an exoplanet only 4.3 light-years away.

但是，假设距离我们仅有4.3光年远的一颗系外行星上，有一头徜徉漫步的大象，我们如果要拍到它，也得使用一个直径有太阳那么大的望远镜。

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Objective To investigate the effect of preparation conditions on the effective diameter and saturation magnetization of dextran magnetic iron oxide nanoparticles.

目的探讨葡聚糖氧化铁磁性纳米颗粒的制备对其有效粒径和比饱和磁化强度的影响。

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The amount of energy that a flywheel will store for a given change in speed depends on its inertia, which, in turn, depends on its mass and its effective diameter.

由于速度的特定变化飞轮存储的能量大小取决于其惯性，其惯性反过来取决于飞轮的质量与有效直径。

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SKA's proponents are talking of scattering its sub-telescopes over an area of 1m square kilometres, which would create an effective diameter of about 1, 000km.

ECONOMIST: Radio telescopes

If the collecting area is in pieces, the effective diameter (the distance between the two most widely spaced pieces) can be several thousand kilometres.

ECONOMIST: Radio telescopes