Uniaxial compression tests at the temperatures of 573–773 K and strain rates of 0.01–10 s−1 were conducted to investigate the hot deformation behavior and microstructural evolution of Al–Cu–Li X2A66 alloy. The results indicate that the main dynamic softening mechanisms of the alloy are dynamic recovery and partial dynamic recrystallization. The flow stress increases obviously with the decrease of temperature or the increase of strain rate. The material constants considering the effect of strain were determined by sixth-order polynomial fitting based on the corrected data. The developed Arrhenius-type constitutive equation coupling temperature, strain rate, and strain was established and could well predict the flow stress in the whole range of temperatures and strain rates except at 1 s−1 and 573 K. Moreover, the values of correlation coefficient and average absolute relative error were calculated, which further proved that the proposed constitutive model has high accuracy and reliability.

In this study, the precipitation behavior of the pretwinned extruded Mg–6Al–1Zn alloy was investigated. It was observed that the precipitates preferentially nucleated at the twin boundaries or within the preexistent twins. This distribution of the precipitates led to the distinguishing influences on subsequent compression and tension process, which were dominated by twinning and detwinning of the preexistent twins, respectively. The compressive yield strength after aging was a little lower than the stress when the precompression was interrupted, which meant that the impeding effect of precipitation on twin expansion was relatively smaller than that of dislocations induced by precompression. However, the tensile yield strength of aged samples was extremely higher than that of non-aged samples as the migration of the twin boundaries during detwinning was considerably hindered because of the preferential precipitation within the preexistent {10-12} twins.

In this paper, low-cost rectifier based on an organic diode for use in organic radio frequency identification (RFID) tags is proposed. Pentacene is the electroactive layer, with 7,7,8,8-tetracyanoquinodimethane (TCNQ) modified low-cost copper (Cu) and aluminum (Al) as the Ohmic and Schottky contacts, respectively. Hole injection barrier between Cu and pentacene can be decreased by forming the self-assembled layers of Cu-TCNQ. The diode shows a high rectification ratio of approximately 2×106 at 5V and the organic diode based rectifier circuit generated a dc output voltage of approximately 2V at 13.56MHz, using an input ac signal with zero-to-peak voltage amplitude of 5 V. The results indicate that chemical modification of the low-cost electrodes could be an efficient way toward low-cost high performance organic electronics devices.

In this invited presentation, we report (1) the assembly of polymer surfactants at the single-walled carbon nanotube (SWNT) and water interface, which not only results in the dispersion of SWNTs in aqueous environments but also provides opportunities for controlled assembly of ternary complexes and the introduction of external stimuli-responsive SWNT dispersions; (2) the first experimental measurement of dc polarization of individual carbon nanotubes using modified scanning force microscopy techniques. The transverse dielectric constant of carbon nanotube is about 10, and this method could be used to distinguish metallic from semiconducting nanotubes.