论文部分内容阅读
无限珍貴的一付天生的眼睛,給予我們观察的本领,通过观察积累了并且丰富了我們的知識。但是一般的观察方法有下面所說的各种局限性。 1.人們的眼睛只是在可見光波段里灵敏。 2.要有一定的光强度,人眼才能看得见。象无灯光、无月光而只有星光的夜间(照度在0.2勒克司左右)人們的眼睛就无从发挥作用了。 3.由于可见光的波長是在4,000到7,600埃范围內,利用可见光成象的光学放大仪器它的分辨本领受到了限制。即便用数值孔徑等于1.40的显微鏡,分辨本領只是在0.2微米左右,若兩个点的距离小于0.2微米时,光学显微鏡就无法分解了。 4.可見光穿透物体的本领較差,所以我們用可见光照明时只能看到不透明物体的表面而不能深入地看
Infinite precious precious pair of natural eyes, to give us the ability to observe, through the observation has accumulated and enriched our knowledge. However, the general observation methods have various limitations as described below. 1. People’s eyes are sensitive only in the visible light. 2. To have a certain light intensity, the human eye can see. Like no light, no moonlight and only the stars of the night (illumination of 0.2 lux or so) people’s eyes can not play a role. 3. Since the wavelength of visible light is in the range of 4,000 to 7,600 angstroms, its resolving power is limited by the use of optical magnification instruments for visible light imaging. Even with a microscope with a numerical aperture equal to 1.40, the resolving power is only about 0.2 microns, and the optical microscope can not be decomposed if the distance between two points is less than 0.2 microns. 4. The ability of visible light to penetrate the object is poor, so we can only see the surface of the opaque object with visible light and can not look deeply