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981.
The effect of a K–Al–F-based flux was investigated on the wettability of TiC by an Al–7 wt%Si alloy in the interval of temperatures
between 660 and 900 °C in Ar and in atmospheric air. Null spreading was observed without flux whereas perfect wetting was
enabled by the flux in both atmospheres. The liquid flux, which provides a locally protective atmosphere by spreading on the
surfaces of the substrate and eventually on the Al alloy, dissolves the aluminium oxide covering the molten alloy enabling
thus direct contact between the liquid alloy and the TiC substrate. The low tensions for the solid/flux and liquid metal/flux
interfaces facilitate spontaneous spreading and instantaneous wetting. Meanwhile, the flux is displaced to the lateral periphery
of the substrate and to the surface of the liquid. Under the resolution of the scanning electron microscope, microstructural
examination of the interfaces did not reveal reaction products. Rapid infiltration of the alloy into TiC/flux compacts, at
low temperatures, correlated well with the flux-assisted spreading kinetics observed. 相似文献
982.
R González J O García M A Barbés M J Quintana L F Verdeja J I Verdeja 《钢铁研究学报(英文版)》2010,17(10):50-56
This research shows, through the analysis of three steels that comply with the EN 10149-2 Euronorm, examples of ultrafine grained (or ultrafine ferrite) ferrous alloys, with ASTM grain sizes close to 14 (2 3 m). These steels are microalloyed with Ti-Nb and have been produced by advanced hot rolling controlled techniques in the factories of ArcelorMittal de Avilés (Asturias, Spain) and are mostly used in automotive and construction applications. By comparison, other techniques to obtain ultrafine grained steels are mentioned, though they have not yet reached the industrial level and are produced in laboratories due to the fact that their mechanical properties (low strain hardening coefficient "n") don't allow cold working operations such as bending, stretching nor drawing. 相似文献
983.
A. Ruiz-Gómez E. Chamizo-Calvo J.M. López-Gutierrez M. García-León A.M. Müller M. Christl 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(7-8):733-735
In this work we present the most recent improvements performed by our group on 10Be measurements on the 1 MV AMS system recently set up at the CNA (Centro Nacional de Aceleradores), in Seville (Spain). Our efforts have been focused on the study of the viability of our system for BeO and BeF? measurements. To achieve this, different standard materials have been measured to demonstrate the reliability of the system for BeO measurements in a wide 10Be/9Be atomic ratio range and several environmental samples have been studied both at the 1 MV AMS CNA facility and at the 6 MV AMS ETH-PSI facility of Zurich to validate our measurements. The results show a good agreement between laboratories. New experiments also have been carried out selecting 1+ and 2+ charge states at the exit of the accelerator and inserting Si3N3.1 foils with different thicknesses to separate 10Be from its isobar, 10B. The influence of each foil on the overall transmission (detected 10Be compared to BeO? injected into the accelerator) and background level was also assessed. In addition some tests were also done to assess the viability of BeF2 and BaBeF4 measurements at our system. Several metal matrices and cathode preparation procedures for BeO samples were investigated to maximize current and cathode lifetime. 相似文献
984.
Full speed range permanent magnet synchronous motor control without mechanical sensors 总被引:1,自引:0,他引:1
Bisheimer G. Sonnaillon M.O. Angelo C.H.D. Solsona J.A. Garc?a G.O. 《Electric Power Applications, IET》2010,4(1):35-44
This study presents a control method for permanent magnet (PM) motors based on a combination of a non-linear full-order observer and a signal injection scheme. Stable mechanical-sensorless operating range down to zero speed at full load is obtained using only voltage and current sensors. The signal injection scheme uses the asymmetry of the motor?s d and q-axis inductances to estimate rotor position and speed. Such asymmetry is also taken into account in the motor model used to construct the observer to reduce current estimation error. The performance of the proposed scheme is validated through experimental results. 相似文献
985.
Hyperspectral Imaging in Tandem with R Statistics and Image Processing for Detection and Visualization of pH in Japanese Big Sausages Under Different Storage Conditions
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986.
Effect of seasonal climate fluctuations on the evolution of glycoconjugates during the ripening period of grapevine cv. Muscat à petits grains blancs berries
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987.
Identification and characterisation of the proteins bound by specific phage‐displayed recombinant antibodies (scFv) obtained against Brazil nut and almond extracts
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988.
989.
990.
Evaluation of visco‐elastic properties of conditioned wheat kernels and their doughs using a compression test under small strain
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