276 research outputs found
Effects of Growth Rates and Cooling Rates on Defect Generation in Melt-Grown Copper Crystals(Physics)
Single crystals of zone-refined Cu were grown from the melt at growth rates ranging from 0.1 to 29.0 mm/min and with cooling rates of the crystal after growth varying from 0.24 to 45℃/min. It was found that the growth rate had a very important effect on the generation of dislocations and their arrays, but the cooling rate of the crystal after growth had an important effect only when the crystal had been solidified at a rate of 0.1 mm/min
A unique vacuolar processing enzyme responsible for conversion of several proprotein precursors into the mature forms
AbstractProprotein precursors of vacuolar components are transported from the endoplasmic reticulum into vacuoles, where they are proteolytically processed into their mature forms. However, the processing mechanism in plant vacuoles is very obscure. Characterization of a purified processing enzyme is required to determine whether a single enzyme is responsible for processing many vacuolar proteins with a large variability of molecular structure. If this is true, how can it recognize the numerous varieties of processing sites? We have now purified a processing enzyme (Mt=37 000) from castor bean seeds. Our results show that the purified enzyme can process 3 different proproteins isolated from either the endoplasmic reticulum or transport vesicles in cotyledon cells to produce the mature forms of these proteins which are found at different suborganellar locations in the vacuole: the 2S protein found in the soluble matrix, the 11S globulin found in the insoluble crystalloid and the 51 kDa protein associated with the membrane. Thus a single vacuolar processing enzyme is capable of converting several proprotein precursors into their respective mature forms
Bose-Einstein Condensation of Europium
We report the realization of a Bose-Einstein condensate of europium atoms,
which is a strongly dipolar species with unique properties, a highly symmetric
electronic ground state and a
hyperfine structure. By means of evaporative cooling in a crossed optical
dipole trap, we produced a condensate of Eu containing up to atoms. The scattering length of Eu was estimated to be by comparing the velocities of expansion of condensates
with different orientations of the atomic magnetic moments. We observed
deformation of the condensate in the vicinity of the Feshbach resonance at
with a width of .Comment: 5 pages, 4 figure
Enhancement of solderability of Cu60Zr30Ti10 bulk metallic glass by dealloying in hydrofluoric acid solution
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