Analyses how to use the platinum rhodium thermocouple analyze the uniqueness of their application

When platinum rhodium thermocouple like air or water flow fast enough, it will suffer a turbulent - Platinum rhodium thermocouple internal pressure and speed of random changes obviously.

to explore turbulence is very difficult, but it is vital for a number of areas of engineering, such as a jet engine or the airflow by platinum rhodium thermocouple. For example, to get better insight into turbulence will allow engineers to develop more efficient turbine blades, or create a more aerodynamic shape for F1.

however, the existing engineering turbulence model is usually dependent on early platinum-rhodium thermocouple based & other; Experience & throughout; Relationship to estimate what will happen, not fully understand the underlying physics.

the problem is quite simple: when the flow in channel of turbulent platinum-rhodium thermocouple is interrupted, the interrupt how scattered in the platinum rhodium thermocouple? For example, if the water from the dam into the river and then suddenly closed, so the dam water pulse what effect can you cause to the river?

in order to find out the platinum-rhodium thermocouple response overall & other; The average & throughout; Behavior, the team must be copied to platinum rhodium thermocouple in many of the smaller the response. Use a supercomputer, they carried out thousands of turbulence simulation, needs billions of calculating every time.

these simulations allow researchers to determine the accurate parameters, in order to explain how the interference dispersion in the flow, and establish the experience turbulence model should satisfy all kinds of conditions.

from my first day platinum-rhodium thermocouple mechanics study, I have some basic questions, I want to know the answer. This is one of them, 40 years after I got the answer right now.

the scientists have been trying to use a technique of submicron crystal full three-dimensional analysis.

3 d analysis was carried out on the crystal structure of demand is the crystal full 3 d view. Can only analyze electronic radiation is less than the powder crystal, side length less than 1 & mu; m。 Technically, impossible to use electron crystallography to complete 360 single crystal & deg; The view.

by Tim of chemistry at the university of Vienna Gruene leadership of a team of scientists has changed the holders of tiny crystals, actively complete with field of vision. At present, the results of their research was published in Nature Communications.

usually, crystallization, use x-rays to study their samples. Size, however, is to analyze the X-ray structure of the important factors: length less than 50 - 100μ M of the crystal is too small and does not produce signals can be quantified.

electron crystallography is a recent development. We showed the chemist colleagues we can analyze the edge crystal - less than 1 micron This includes many crystals, these crystals are not so far to determine 3 d structure.

limited view

compared with X-ray, electron interaction with the material is very strong. Once with electron irradiation sub-micron size crystal, produce characteristic diffraction image. Although these provide data for structure analysis, sample frame can prevent the full 360 & deg; Rotation.

at present, there is only one axis is available, and fine samples necessary for stable metal strip can not be electronic penetration. Can only rotate in any direction about 75 & deg; 。

their research provides two solutions to avoid this problem. First of all, they are ready to sample, to look at crystal from all directions, and there are multiple crystals in a rack, enough to complete the data and provide accurate 3 d view.

to deceive the carrier

ultrathin carbon layer of the carrier material are simple and easy to use program, the program involves the use of fine brush.

the second solution including carbon carrier are nylon fiber. Tim & middot; Global within said: & other; These are similar to forest cover the surface of the forest. ” Once they deposited in the sample rack, this in turn leads to different crystal of arbitrary orientation. Nylon fiber by electrostatic spinning collection, however, this requires additional equipment and more complex than touch it with the brush.

” Neat and simple & throughout;

both program provides a data set from the crystal, complete with 3 d structure analysis. This combination is typically used for protein crystallography data sets, but fewer in the chemical crystallography.