Polytypes of long-period stacking structures synchronized with chemical order in a dilute Mg–Zn–Y alloy

A series of structural polytypes formed in an Mg–1 at.%Zn–2 at.%Y alloy has been identified, which are reasonably viewed as long-period stacking derivatives of the hexagonal-close-packed Mg structure with alternate AB stacking of the close-packed atomic layers. Atomic-resolution Z-contrast imaging clearly revealed that the structures are long-period chemical-ordered as well as stacking-ordered; unique chemical order along the stacking direction occurs as being synchronized with a local faulted stacking of AB′C′A, where B′ and C′ layers are commonly enriched by Zn/Y atoms.     

Re-precipitation of coherent γ-Fe particles following annealing of equal-channel angular pressed Cu–Fe alloy

The transformation of second-phase particles in a Cu–Fe alloy following equal-channel angular extrusion and annealing has been determined by transmission electron microscopy. Equal-channel angular pressing of the Cu–Fe alloy transformed coherent γ-Fe particles in the Cu matrix into incoherent α-Fe. Upon annealing, numerous coherent γ-Fe particles were observed. A dislocation–particle interaction mechanism is suggested to explain the re-precipitation of coherent γ-Fe particles following annealing.     

Temperature dependence of nucleation rate in a binary solid solution

The influence of regression (partial dissolution) effects on the temperature dependence of nucleation rate in a binary solid solution has been studied theoretically. The results of the analysis are compared with the predictions of the simplest Volmer–Weber theory. Regression effects are shown to have a strong influence on the shape of the curve of nucleation rate versus temperature. The temperature T_M at which the maximum rate of nucleation occurs is found to be lowered, particularly for low interfacial energy (coherent precipitation) and high-mobility species (e.g. interstitial atoms).     

Microstructural evolution of single-walled carbon nanotubes under electron irradiation

A sample containing single-wall carbon nanotubes (SWCNTs) has been annealed at 900°C and then irradiated by high-energy electrons in an ultrahigh-vacuum transmission electron microscope. Sequential high-resolution images showed that the structures of SWCNT bundles and individual SWCNT segments first collapsed into disordered and fullerene-like carbon materials and then reorganized into graphitic particles under continuous electron irradiation. The speed of structural evolution is dependent on the flux density of the electron irradiation.     

Observation of phase separation in magnetron sputter-deposited Al–Cu thin films

The microstructures of Al–1.8 to 92.5?at.% Cu thin films prepared by radiofrequency (13.56?MHz) cathodic magnetron sputtering have been investigated by X-ray diffraction (XRD) and transmission electronic microscopy (TEM). A phase separation occurs in films of nominal Al–66.64?at.% Cu composition, consisting of a fcc Al solid solution phase, a fcc Cu solid solution phase and an unexpected sc Cu₃Al ordered phase with a Cu₃Au structure and a lattice parameter of about 0.36?nm.     

A first HREM observation of the ordered carbon sublattice in a transition-metal carbide (VC1-x)

Abstract

The microstructure of long-range-ordered vanadium carbides based on V₆C₅ has been analysed by means of high-resolution electron microscopy (HREM). Lattice images have been produced by including in the objective-aperture superlattice spots associated with the ordered distribution of vacancies in the interstitial carbon sublattice of these substoichiometric compounds: ‘perfectly’ ordered structures have been imaged, and a direct discussion of the experimental micrographs is made in terms of positions of the vacancy-containing columns. This HREM study will soon be extended to theinvestigation of various kinds of planar defects within differently annealed specimens.     

Ishmael as Abraham's Sacrifice: Ibn Taymiyya and Ibn Kathīr on the Intended Victim

This article examines how Ibn Taymiyya and Ibn Kathīr shift the Islamic exegetical tradition towards accepting Ishmael as Abraham's intended sacrifice. Earlier exegetes, such as al-?abarī, maintained that Isaac was the intended sacrifice through a philological analysis of the qur'anic text. Contrary to expectations, Ibn Taymiyya and Ibn Kathīr do not only use Prophetic reports (Hadith) to make their case but also employ biblical and philological arguments. The modern dominance of Ibn Taymiyya's qur'anic hermeneutic and the popularity of Ibn Kathīr's qur'anic exegesis have influenced Islamic orthodoxy to hold that Ishmael was the sacrificial son and to be more skeptical of biblical sources.     

Predicting eating problems among Malaysian Chinese: Differential roles of positive and negative perfectionism

Positive and negative perfectionism (measured by the Positive and Negative Perfectionism Scale; PANPS) are found to have differential roles in predicting eating problems. This study translated and back-translated the PANPS into Chinese and then examined whether its factor structure was comparable to the original PANPS. The relationships between positive and negative perfectionism (using Chinese PANPS) and eating problems were also evaluated. Malaysian Chinese (N = 205) adults completed the Chinese PANPS, Eating Disorder Inventory (EDI) and Marlowe-Crowne Social Desirability Scale. Principal Component Analysis showed the two-factor solution of the Chinese PANPS accounted for 33.42% of the total variance, which was comparable to previous studies. Hierarchical multiple regressions revealed that negative perfectionism significantly predicted all eating disorder symptoms for females, but not drive for thinness and body dissatisfaction for males. Conversely, positive perfectionism significantly predicted lower total EDI scores, lower ineffectiveness and lower interpersonal distrust, but only predicted lower body dissatisfaction among females. In conclusion, negative perfectionism was consistently associated with eating problems whereas positive perfectionism might be a potentially adaptive factor, confirming the distinctive roles each played in the development of eating problems, even in a non-Western population.