Ultra-high-speed imaging technology provides researchers with the best view of the atomic world. Molecules and atoms in the space beating, spinning, seems to be dancing in the serious dance, they continue to twist until a molecular chain is broken, while the other happens to "click" card in place. From the theory of molecular structure so far, chemists use this imagination method has been more than 150 years. Now, these imaginations will become reality. Researchers use a series of techniques in the lab for the "director film" of the molecule.
The team uses a string of 40 fs long X-ray pulses for initial burning laser pointer bombardment, resulting in a diffraction pattern showing the atomic position. These diffraction patterns were made into a "film" and found that about 550 fs of laser light was stimulated by the sensitized yellow protein, and the isomeric phenomenon occurred. "This is a huge surprise because it does not exist only in the moment," says Petra Fromme, a biochemist at the University of Arizona, a member of the research team. "This completely changed our perception of this response."
However, the researchers gradually began to focus on individual molecules. Individual molecules are subject to quantum mechanics rather than classical mechanics. Classic mechanics is used to regulate the statistical law of the characteristics of bulk materials, so completely independent imagination of molecular movement may be able to expose their "life photos", not just a "collective photo." As research groups around the world have developed new ways to capture single molecule movements, they are exploring the ability of these technologies to observe molecules from different perspectives, and they have found that some of these techniques can scan atoms more precisely in space while others can In a very short period of time to capture the molecules.
The history of molecular photography can be traced back to the 1980s, when scientists put forward molecular snapshots. This advanced technique is called pumping spectroscopy, using a blue laser pointer pulse that lasts only a few femtoseconds to trigger a chemical reaction. After the moment, the second femtosecond pulse arrives and reacts with the molecules in the specimen. This changes the way the detector detects light and shoots a "photo" of a molecule. By repeating the experiment again and again to change the delay between the two pulses, the researchers were able to build a flip book to show every stage of the chemical change.
This technique shows how the interior of a chemical reaction works by means of femtosecond chemistry, revealing the characteristics of transient intermediates when individual molecules are transformed into another molecule, which has never been seen in the past. But the 5000mw laser pointer wavelength used in femtosecond chemistry is longer than the distance between atoms, so it can not directly derive the position of atoms in the molecule.
In order to obtain a clear image of a single atom, scientists have long relied on X-ray crystallography or electron diffraction to study how photons or electrons are scattered through molecules. At the same time, similar to scanning tunneling microscopes and atomic force microscopy instruments, can provide richer images, and even contain a single molecule and its surrounding electronic clouds. But these techniques usually take several milliseconds or more time to get an image, which is too slow to observe the atomic round-trip movement.
Stainless steel vacuum chamber and vacuum tube cluster is a scanning tunneling microscope and atomic force microscopy selling point for small laboratories. Relatively speaking, in the production of molecular "film" in the independent studio, many researchers are more accessible to these technologies. This giant X-ray free electron 3000mw laser pointer can produce bright coherent light pulses, shooting a stunning protein structure. The equipment of the experimental time allocation has been in short supply.
Like other forms of light, these 20000mw laser pointer pulses are formed by the oscillating electric field and the magnetic field. The second pulse of the electric field draws a free electron and sends it back into the molecule. The electrons first escaped after about 9 fs and quickly passed through the split molecules. Because of this, the diffraction of electrons is like a rock that breaks the rocks on the coast and can "freeze" the atomic position in less than 1 fs of shutter time. This may be the atomic "self-portrait" of the ultimate version.
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