Together- 4 -ever @together_4_ever

عضوة نشيطة

ساعدوا صديقتي محتاجه بحت في هذ االموضوع

الله يعافيكم ويرزقكم ويحقق لكم ماتتمنون

ساعدوا صديقتي في الجامعه وعليها بحث بالانجليزي عن مقارنه ىبين المجهر الضوئي والماسح الالكتروني من ناحية التركيب والمميزات والعيوب والاستعمالات وحجم التكبير صور ورسوم ومخططات والانتشار واي شيء ثاني بالانجليزيSIZE] تكفون بسرعه صفحه او صفحتين البحث مطلوب غدا التسليم تكفون ساعدوها ياحلوين

523

يلزم عليك تسجيل الدخول أولًا لكتابة تعليق.

تسجيل دخول

Together- 4 -ever • 13 سنة

تكفون ساعدوني لو برفع الموضوع

Together- 4 -ever • 13 سنة

وينكم بنات ساعدوني

انسانة ن • 13 سنة

مشي حالك بالكلام هاد....موفقة حاولي تعملي أمورك يا اختي قبل التسليم بفترة مو على آخر وقت المهم تكوني فاهمة المكتوب إن شاء الله.....سلام
The first electron microscope was patented in 1931 by Reinhold Rundenberg of Siemens. While the first one was much less powerful, modern electron microscopes can magnify an image up to two million times its original size. To get an idea of the scale, an electron microscope is able to see individual nucleic acids, the building blocks of our DNA.
An electron microscope produces its ultra fine image by passing a particle beam of electrons through electrostatic or electromagnetic lenses, similar to the principle of a light microscope. However, since the wavelength of an electron beam is so much shorter. A shorter wavelength means a higher resolution.
Electron microscopes are a general category in which there are several varieties. The two most common are transmission electron microscopes and scanning electron microscopes. Both use a beam of electrons to view the very small, but the beam acts in different ways.
A transmission electron microscope uses a high-powered beam to essentially shoot electrons through the object. The electron beam first passes through a condenser lens in order to concentrate the beam on the object. Then the beam goes through the object. Some of the electrons pass all the way through; others hit molecules in the object and scatter. The modified beam then passes through an objective lens, a projector lens and onto a fluorescent screen where the final image is observed. Because the electron beam passes entirely through the object, the pattern of scatter gives the observed a comprehensive view of the interior of the object.

A scanning electron microscope doesn’t use a concentrated electron beam to penetrate the object, as a transmission electron microscope does. Instead it scans a beam across the object. During the scanning the beam loses energy in different amounts according to the surface it is on. A scanning electron microscope measures the lost energy to create a three-dimensional picture of the surface of an object. While not quite as powerful as a transmission electron microscope, a scanning electron microscope is able to produce comprehensive magnified images of much larger objects, like that of an ant.
Recently, other electron microscopes have been developed that combine transmission and scanning technologies. However, all electron microscopes, transmission, scanning or otherwise employ the basic principle of magnifying an object through the use of an electron beam.

Together- 4 -ever • 13 سنة

جزاك الله خير ياقمر