如图3-30所示,一平面镜置于充满水的容器的底部,人俯视平面镜看自己的像,设眼睛高出水面h1=10cm,而镜子在水面之下深h2=66.5cm。试求眼睛在镜子中看起来与眼睛的距离(水的折射率为4/3)。
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1.The teacher has requested the students to( )in red the words which have been spelled incorrectly.
2.The historians use the( )on the walls of ancient temples to guide them in their research.
3.During the interview,he asked me to( )what kind of things I do in my spare time.
4.A( )is the piece of paper on which your doctor writes an order for medicine and which you then give to a chemist or pharmacist to fill the order.
5.He( )his low mark to the noisy study environment.
6.My main reason for( )to New Scientist is to keep abreast of advances.in science.
与理想光学系统相比。实际光学系统的成像光束口径和成像范围都受到限制,多数系统存在渐晕现象。①渐晕是由于孔径光阑的拦光作用而产生的。②渐晕使成像平面的照度不均匀。③轴外点成像光束的宽度不只与孔径光阑有关,而且和渐晕光阑有关。④孔径光阑的位置影响轴上点成像光束的选择。
在显微系统中加入不同焦距的场镜后,会给系统带来如下影响:①场镜的焦距越短,在保证相同渐晕系数的情况下,目镜的通光口径会越小。②场镜的焦距越短,在保证相同渐晕系数的情况下,物镜的通光口径会越小。③场镜的焦距越短,出瞳尺寸会越大。④场镜的焦距越短,系统的放大率会越大。