| 1. | Just as a double convex lens enlarges , so a double concave lens reduces 正象双凸透镜可以放大那样,双凹透镜也可以缩小。
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| 2. | This setup , known as a conoscope , is shown in figure 14 . 2 and consists of two stress - free plano - convex lenses a and b 此装置称为锥光镜,如图14 2所示,它由a和b两个无应力平凸透镜组成。
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| 3. | However , spectacles are made of thick convex lens . skills and precautions are needed to wear contact lens properly . both are not suitable for the elderly 不过,这些眼镜片有相当的厚度,配戴隐形眼镜亦需要一些特别技巧,对于年纪较大的患者未必适合。
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| 4. | This setup , known as a conoscope , is shown in figure 14 . 2 and consists of two stress - free plane - convex lenses a and b and a diaphragm c having a small aperture 此装置称为锥光镜,如图14 2所示,它由a和b两个无应力平凸透镜和一个带小孔的光阑c组成。
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| 5. | However , spectacles are made of thick convex lens . skills and precautions are needed to wear contact lens properly . both are not suitable for the elderly 不过,这些眼镜片有相当的厚度,配戴隐形眼镜亦需要一些特别技巧,对于年纪较大的患者未必适合。
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| 6. | Since lenticular clouds look like one or more convex lens , they could sometimes be misinterpreted as flying saucers or unidentified flying objects , and so they are commonly known as " flying saucer clouds " 由于这类荚状云形状像一块或多块凸透镜,有时候被误会为飞碟或不明飞行物体,所以亦俗称飞碟云。
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| 7. | Analysis showed this might be due to the fact that a black hole passed in front of the star . the gravitation of a black hole can function as a convex lens and focus starlight , resulting in transience increase of apparent brightness of the star 分析显示,这很可能是因为有一个黑洞在恒星前面经过,黑洞的引力会聚了星光,就像凸透镜把光线聚焦一样,使恒星的视亮度增加。
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| 8. | The gravitation field of star b bends the light from star a as a convex lens does and we can observe a sudden brightening of star a . much brighter than the total brightness of star a and b . this phenomenon is called microlensing 根据国际天文学联会international astronomical union于2006年8月24日通过的行星定义,冥王星的行星资格被取消,并被界定为一类称为矮行星的新天体。
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