Study the temperature dependence of resistivity of high purity aluminum fine showed that up to temperatures of 10-12K a mechanism of electron scattering at grain boundaries dominates the electron-dislocation scattering, then the effect is suppressed by electron-phonon scattering. Analysis of the results of the first studies show that the problem of producing and studying fine (in the limit of nanocrystalline) of pure metals is relevant to a winding giperprovodyaschih cryogenic electromagnetic systems. |
|
Results of the study of quantum oscillations of the kinetic coefficients in terms of magnetic breakdown obtained for dilute alloys of Al-Y and Zn-In, indicate that the doping metals properly chosen type and concentration of impurities lead to a change in geometry and size of sheets of the Fermi surface.
|
Read more...
|
Studies of the deformation contribution to the resistivity of dilute alloys of Al-Y and Al-Ga shows the difference in temperature dependence of this quantity in a high transverse magnetic field and in his absence. |
Read more...
|
Conducting highly-pures aluminum fibres are placed into the matrix of high-strength Al alloy, which is suitable for their joint working and operation. This fabrication technology allows a reliable electrical and thermal contact of a matrix and a conductor. A multi-fibre conductor, consisting of the Al-Mn-Mg alloy with the 94% aluminum content, which has a high yield limit σy = 360 МPа при Т = 4.2 К, and also heat conductivity and linear expansion coefficient being close to those of pure Al. |
Read more...
|
A physical model of current flow in from high-purity aluminum giperprovodnike, taking into account the effect of the magnetic stray field of the self-field coil, which allowed to optimize the design of the winding because of its banding on the mechanical loads and flow-through cooling with liquid hydrogen. When choosing a winding structure the main criterion is to protect the plastic guide from the radial and axial strain. This is ensured by a special coil banding and strong material allows to maintain the high conductive properties of high-purity aluminum and provide a current density of 200 A/mm. Obtained at this stage of the assignment results confirm the fundamental possibility of generating strong magnetic fields in compact solenoidal systems promising for use in power systems on board spacecraft. |
Read more...
|
Investigated the temperature dependence of resistivity of ionic compounds [C4mim] PF6 and [C6mim] NTf2. In all cases the samples are cooled to 77 K there is growing resistance to a law close to parabolic. When heated to the crystallization temperature on the curves of lnR (T) anomalies in the temperature range corresponding to the supercooled liquid state. The value of resistivity in the crystalline state are different for these compounds. In the case of [C4mim] PF6 resistance less than the state of the glass, for [C6mim] NTf2 the opposite is true. |
Using frozen lactic acid bacteria in the atmosphere of liquid nitrogen can increase the number of living cells and has no effect on the ratio of bacterial cultures in the starter. Scientific-technical principles and an experimental model system for kriozamorazhivaniya microbial biomass. |
Read more...
|
|
|
<< Start < Prev 1 2 3 4 Next > End >>
|
Page 3 of 4 |