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.

Luminescent biolabels are being eagerly investigated as a means of detecting cancer cells by bioimaging. Upconversion nanoparticles are a promising option to be used as biolabels for cancer cell detection. This process uses a near infrared beam (NIR λ = 980 nm) as the excitation source to upconvert the energy into light in the visible region. The present study, used Y2O3:Yb3+, Er3+ (1%, 10% mol) and Gd2O3:Yb3+, Er3+ (1%, 10% mol) capable of emitting red photons of λ = 660 nm. The nanoparticles were previously functionalized with aminosilanes and folic acid (UCNP-NH2-FA). Folic acid binds to the folate receptor on the surface of MCF-7 breast cancer cells, and this binding promotes internalization of the UCNPs via endocytosis. The UCNPs were characterized by TEM, EDS, and Fourier transform infrared. Cytotoxicity was also analyzed using the MTT (methy-134 thiazolyltetrazolium) colorimetric assay. The UCNPs-NH2-FA was noncytotoxic to the studied cancer cells and they were clearly localizable within the cell cytoplasm via confocal microscope.

The temperature programmed molecular dynamics (TPMD) method is a recent addition to the list of rare-event simulation techniques for materials. Study of thermally-activated events that are rare at molecular dynamics (MD) timescales is possible with TPMD by employing a temperature program that raises the temperature in stages to a point where the transitions happen frequently. Analysis of the observed waiting time distribution yields a wealth of information including kinetic mechanisms in the material, their rate constants and Arrhenius parameters. The first part of this review covers the foundations of the TPMD method. Recent applications of TPMD are discussed to highlight its main advantages. These advantages offer the possibility for rapid construction of kinetic Monte Carlo (KMC) models of a chosen accuracy using TPMD. In this regards, the second part focuses on the latest developments on uncertainty measures for KMC models. The third part focuses on current challenges for the TPMD method and ways of resolving them.

Detection of chlorpyrifos (CPF) using a surface plasmon resonance (SPR)-enhanced photoelectrochemical sensing system is demonstrated in this study. The presence of CPF was detected based on an increase in the short-circuit photocurrent when a sample is injected into the electrolyte at different concentrations. The short-circuit photocurrent signal was enhanced by both localized SPR of the gold nanoparticles and by the effects of grating-coupled propagating SPR. Using the hybrid SPR-enhancement system, CPF detection was achieved at concentrations as low as 7.5 nM. The proposed technique of leveraging a multifunctional photovoltaic effect can be used for a variety of sensing applications.

Nitrogen-doped graphene (N-G) is a promising non-platinum group metal catalyst for oxygen reduction reaction. A new N-G/metal organic framework (MOF) catalyst is derived by the modification of MOF on N-G catalysts to enhance the electrochemical performance of N-G by increasing the surface area and porosity in this paper. The characterization confirmed that the Brunauer–Emmett–Teller surface areas of N-G/MOF catalysts are 13–66 times larger than the original N-G catalyst. The highest current density (5.02 mA/cm2) and electron transfer number (3.93) of N-G/MOFs are higher than the N-G catalyst. The current density of N-G/MOF catalyst is even higher than 10 wt% Pt/C catalyst.

Molecular dynamics (MD) is one of the most widely used techniques in computational materials science. By providing fully resolved trajectories, it allows for a natural description of static, thermodynamic, and kinetic properties. A major hurdle that has hampered the use of MD is the fact that the timescales that can be directly simulated are very limited, even when using massively parallel computers. In this study, we compare two time-parallelization approaches, parallel replica dynamics (ParRep) and parallel trajectory splicing (ParSplice), that were specifically designed to address this issue for rare event systems by leveraging parallel computing resources. Using simulations of the relaxation of small disordered platinum nanoparticles, a comparative performance analysis of the two methods is presented. The results show that ParSplice can significantly outperform ParRep in the common case where the trajectory remains trapped for a long time within a region of configuration space but makes rapid structural transitions within this region.