Diamond features a unique combination of outstanding physical properties perfect for numerous x-ray optics applications, where traditional materials such as silicon fail to perform. In the last two decades, impressive progress has been achieved in synthesizing diamond with high crystalline perfection, in manufacturing efficient, resilient, high-resolution, wavefront-preserving diamond optical components, and in implementing them in cutting-edge x-ray instruments. Diamond optics are essential for tailoring x-rays to the most challenging needs of x-ray research. They are becoming vital for the generation of fully coherent hard x-rays by seeded x-ray free-electron lasers. In this article, we review progress in manufacturing flawless diamond crystal components and their applications in diverse x-ray optical devices, such as x-ray monochromators, beam splitters, high-reflectance backscattering mirrors, lenses, phase plates, diffraction gratings, bent-crystal spectrographs, and windows.

A highly sensitive impedance sensor operating at room temperature has been developed for the quantitative determination of formaldehyde vapor. Nanostructured zinc oxide (ZnO) was synthesized by chemical reduction and used, in the form of a pellet, as the sensing material. Its performance was compared to that of the pellet made from commercial ZnO. Both samples were characterized by X-ray diffraction, Fourier transform infra-red spectroscopy, ultraviolet–visible spectroscopy, and atomic force microscopy techniques. Changes in impedance caused by formaldehyde in the concentration range from 100 to 800 ppm were measured and Nyquist plots revealed a systematic variation in impedance. The sensor response and formaldehyde concentration are exponentially correlated for both the laboratory synthesized and commercial ZnO samples. However, the lab-synthesized sample displays a better performance in terms of sensitivity, response, recovery, and stability. In addition, the response of the lab-synthesized sample is less sensitive to interferences by reducing gases such as ammonia, ethanol, methanol, and propanol.

It is common knowledge that chromophore aggregation usually quenches light emission. The concept of aggregation-induced emission (AIE) changes this general belief and provides a new stage for the exploration of practical luminescent materials. The weak emission of AIE fluorogens (AIEgens) as molecular species and their bright fluorescence as nanoscopic aggregates distinguishes them from conventional organic luminophores and inorganic nanoparticles, making them ideal candidates for high-tech applications. This article summarizes the impact of AIEgens in biomedical applications.

SiC nanoparticles reinforced magnesium matrix composite was fabricated by ultrasonic vibration assisted squeeze casting. Since ultrasonic device could meet the use requirements according to theoretic calculation, uniform dispersion of SiC nanoparticles was expected to achieve. The grains of the composite were refined compared with the AZ91 alloy, which was related to the increase of nucleation sites during solidification and Zenner pinning effect caused by SiC nanoparticles. With increasing the ultrasonic power, grain size of the composite changed no obviously while the morphology of β-Mg17Al12 phase was significantly affected. The ultimate tensile strength, yield strength, and elongation to fracture of the composites fabricated under different ultrasonic powers were simultaneously improved compared with the AZ91 alloy. The increase of yield strength could be attributed to Hall–Petch strengthening and Orowan strengthening for the present composites. Theoretical value of the yield strength obtained by the square root method was close to the experimental value.

In vitro electrophysiology using microelectrode arrays (MEAs) plays an important role in understanding fundamental biologic processes, screening potential drugs and assessing the toxicity of chemicals. Low electrode impedance and ability to sustain viable cultures are the key technology requirements. We show that MEAs consisting of poly(3,4-ethylenedioxythiophene) doped with poly(styrene sulfonate) (PEDOT:PSS) and coated with poly-L-lysine satisfy these requirements. Hippocampal cell cultures, maintained for 3–6 weeks on these MEAs, give high quality recordings of neural activity. This enables the observation of drug-induced activity changes, which paves the way for using these devices in in vitro drug screening and toxicology applications.

Cyclic deformation and low-cycle fatigue behavior of Mg–10Gd–3Y–0.5Zr alloy in sand-cast and aging treatment conditions (sand-cast-T6) were investigated by carrying out full reversed strain-controlled tension-compression tests at the strain amplitude ranging from 0.25 to 0.7%. The results show that stress–strain hysteresis loops of the studied alloys display near tension-compression symmetry, which is dominated by microstructure and strain amplitude. Both sand-cast and sand-cast-T6 alloys exhibit cyclic hardening and softening phenomenon with increasing loading cycles. Meanwhile, the fatigue life of the aged alloy is higher than that of the sand-cast alloy at all applied strain amplitudes. The theoretical strain fatigue limits (ε0) of sand-cast and sand-cast-T6 alloys are 2.1% and 2.3%, respectively. In addition, the low-cycle fatigue behavior of the studied alloy at different strain amplitudes was also investigated.

0.62[0.75(Pb(Mg1/3Nb2/3)O3)–0.25(Pb(Yb1/2Nb1/2)O3)]–0.38(PbTiO3) ceramics were successfully textured in [001] via the template grain growth method using 1–7 vol% platelike BaTiO3 (BT) templated (the Lotgering factor of 0.91 at 5 vol% BT). Dielectric spectra indicated a normal ferroelectric behavior without any frequency dispersion and no low-temperature phase transition. The chemically stable BT phase within the matrix gave rise to a composite effect and its relatively inferior properties affected the dielectric and electromechanical properties. The lower T C of the BT decreased the Curie temperature from 226 to 213 °C (with a depolarization temperature of 204 °C). Significantly higher levels of strain (0.33%), narrower hysteresis level (7.7%), higher piezoelectric strain coefficient (660 pm/V), and low-field (<5 kV/cm) piezoelectric strain coefficient (1340 pm/V) at 50 kV/cm were achieved at 5 vol% BT addition. These results are very promising for the fabrication of high performance transducer and actuator applications without severe temperature limitations.

Low volume fraction (0.5, 1, and 2 vol%) SiO2 reinforced magnesium nanocomposites were synthesized using powder metallurgy technique followed by hot extrusion. The nanocomposites were studied for physical, microstructural, ignition, and mechanical properties to study the influence of nanoparticulate addition on monolithic magnesium. The grain size of the developed nanocomposites was observed to marginally decrease with the addition of SiO2 nanoparticulates with 2 vol% SiO2 addition resulting in a grain size of ∼23 μm which is ∼32% lower than that of pure Mg. The ignition temperature of pure Mg was enhanced with the addition of SiO2 nanoparticulates with Mg 2 vol% SiO2 nanocomposite exhibiting an ignition temperature of 611 °C (∼20 °C greater than pure Mg and AZ31 alloy). Under room temperature tensile loading, Hall–Petch strengthening mechanism was the most dominant wherein the addition of SiO2 nanoparticulates to pure magnesium enhances the strength within 0–2 vol% range and ductility in 0–1 vol% range.

The aim of this study is to investigate the effects of different master alloys containing Ti, B, and Zr on the structure and tensile properties of thin-section A356 aluminum alloy in as-cast and T6-treated conditions. Microstructural examinations were performed using light optical and scanning electron microscopy. The results showed that the addition of 0.1 wt% Ti, 0.05 wt% B, and 0.1 wt% Zr decreases the average grain size of the cast alloy from 840 μm to 387 μm, 236 μm, and 363 μm, respectively. This structural refinement results in the variation of the α-Al primary phase distribution mode from dendritic to rosettelike. It has been found that 0.6 wt% Al–8B master alloy (0.05 wt% B) is the strongest to refine the structural parameters. This leads to the enhancement of both ultimate tensile strength and elongation values from 208 MPa and 6.2% in as-cast to 290 MPa and 12.5% in B-refined alloy at T6-treated conditions. In addition, the presence of more fine dimples on the fracture surfaces of the T6-treated specimens revealed that T6-treatment encourages ductile mode of fracture.

A superelastic Ti–40Nb alloy enhanced with Cu element (0, 2.5, 5, 7.5, and 10 wt%) was synthesized by a spark plasma sintering method to obtain biomaterials with an antimicrobial effect. The microstructure results showed that β phase was the main phase in (Ti–40Nb)–Cu alloys while Ti2Cu was synthesized with the Cu addition above 5 wt%. (Ti–40Nb)–Cu alloys exhibited high compressive strength over 1693.08 MPa, high yield strength of 1140.26–1619.14 MPa, low elastic modulus in the range of 43.91–58.01 GPa, low elastic energy (14.81–24.73 MJ/m3), and together with large plastic strain over 18.5%. High concentration of Cu ion released steadily from alloys in early 7 days, then the released concentration of Cu ion showed long-lasting and moderate. Comparing with the Ti–40Nb alloy, high antimicrobial activity was pronounced on (Ti–40Nb)–Cu alloys, and (Ti–40Nb)–Cu alloys showed more inhibitory activity against bacteria (E. coli and S. aureus) than fungi (C. albicans). Cu contents in alloys influenced the Cu ion release, which in turn affected the antimicrobial activity. As a good combination of low elastic modulus, high mechanical properties, good elastic energy, and excellent antimicrobial performance, (Ti–40Nb)–Cu alloys offer potential advantages to prevent stress shielding and exhibit an excellent antimicrobial property for hard tissue replacements.