On the synthesis and characterisation of novel composite-structured high-entropy alloys

A study of novel composite-structured CoCrFeNi₃Si, CoCrFe₂Ni₂Si and Co₂CrFeNi₂Si high-entropy alloys, synthesised by vacuum arc melting, is presented. The designing criteria for the formation of such alloys were based on the enthalpy of mixing and the valence electron concentration. X-ray diffraction analysis revealed that all the alloys were composed of face-centered cubic and intermetallic phases. Scanning electron microscopy, along with elemental analysis, indicated that the face-centered cubic phase mainly contains Co, Cr, Fe and Ni, whereas, the intermetallic compound is Ni-Si rich. All the synthesised high-entropy alloys in the present investigation possess excellent compressive strength along with ductility at room temperature, suggesting significant potential application in the engineering field. Furthermore, enhanced hardness, wear resistance and corrosion resistance were achieved in all the designed high-entropy alloys. The previously given design parameters for the composite-structured high-entropy alloys are in good accord with the current research work.     

Correlation between ductility and work function in NiAl–Ce–Cr alloys

In spite of many superior high-temperature properties of intermetallics, it has been difficult to understand their intrinsic brittleness. To eliminate or improve the embrittlement, the conventional alloying technique based on the trial-and-error method is still the most effective and practical. However, it remains a main challenge for both physicists and materials scientists to provide either an alloying principle or a deep insight into its toughening mechanism at an atomic or electronic level. This letter reports a simple experimental approach that uses work function (WF) as a sensitive indicator of the role of alloying in changing mechanical behavior. NiAl is chosen as a typical example. It is found that with the addition of Cr and Ce, the ductility of NiAl increases significantly. Such an increase in ductility corresponds to a concomitant decrease in the WF, which is attributed to a change in the nature of the atomic bonding or in the electronic structure induced by the alloying. This fundamental understanding on the embrittlement nature of NiAl could provide some alloying guidelines or principles for other intermetallics.     

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.     

On the possibility of tuning the energy separation between space-quantized levels in a quantum well

The idea about change of energy distances between space-quantized energy levels by ionization of an impurity delta layer situated within a quantum well (QW) is put forward and justified. The self-consistent solutions of Schrödinger, Poisson, and electroneutrality equations made for n-type SiGe/Si/SiGe rectangular QW show that the effect really exists and the most dramatic changes can be observed for an edge-delta-doped QW structure.     

Site preference of refractory elements in γ′-Ni3Al alloyed with Ru

The influence of ruthenium (Ru) on the partitioning behavior of W, Re and Cr in γ′-Ni₃Al has been studied using the Dmol3 method based on the density functional theory. The calculated results show that W, Re and Cr have a preference for the Ni site in γ′-Ni₃Al alloyed with Ru. When Ru substitutes the central Ni atom, the site preference for W, Re and Cr varies. Furthermore, an electronic structure analysis of the alloy in terms of the Mulliken population and partial density of states was performed to elucidate the alloying mechanism of Ru in γ′-Ni₃Al. The results show that the strengthening effect of Ru in the alloy arises from a reduction in the binding energy of Ru as well as p-orbital hybridization between Ru and the host atoms.     

General and supplementary factors of personality in genetic and environmental correlation matrices

Genetic and environmental correlation matrices among 7 personality scales were estimated, using samples of adult and young adult twins from Australia (2081 and 1178 pairs, respectively). A general factor of personality and two supplemental factors were obtained in each. The supplemental factors were tentatively identified as Social conformity and Other-dependence. Factors from the genetic and environmental correlations replicated well across samples, and they were similar in both the genetic and environmental covariation. It was concluded that the structure of personality is inherent in the evolved phenotype, and is not the immediate consequence of either genetic or environmental organizing factors.     

Utopia and heightened consciousness

Utopia should not be seen as the end‐point of a continuum of material progress, but as a society whose members enjoy a consciousness raised to its highest attainable level of intensity and value. The urge towards heightened consciousness is seen as a primary, pleasure‐driven human impulse, comparable in scope and intensity to the sex drive and perhaps still more fundamental, in that it emanates from the primordial human organ, the brain. The article explores ways in which an ‘inhibition barrier’ at present limiting the intensity of individual and general consciousness and arising from survival‐orientated modes of perception and feeling, might be raised or removed by a specific modification both of basic mental structures governing perception and conceptualization, and of economic structures, enabling a more efficient but non‐competitive mode of generating and distributing wealth. Insights derived from the psychology of art are thus applied more widely to the process of social living, to generate a concept of an attainable Utopia which would redirect human motivation away from ecologically destructive preoccupations.     

Close monitoring as a contextual stimulator: How need for structure affects the relation between close monitoring and work outcomes

In this article, we argue and demonstrate that employees’ Personal Need for Structure (PNS) moderates the negative effects of close monitoring on job satisfaction, intrinsic work motivation, and innovative job performance (as rated by their supervisors). In a field study (N = 295), we found that employees low in PNS reacted unfavourably to close monitoring, whereas employees high in PNS reacted more favourably to close monitoring. Furthermore, we demonstrate that the negative effect of close monitoring on job satisfaction and intrinsic work motivation among low PNS employees can be explained by a reduction of perceived autonomy. In contrast, the positive effects of close monitoring on these favourable outcomes among high PNS employees were associated with increased role clarity.     

我国运动员主观幸福感内部结构及外部影响因素研究

通过探索我国运动员主观幸福感的内部结构,并对我国运动员主观幸福感的外部影响因素进行分析。研究结果发现,我国运动员主观幸福感由7个二级指标及38个三级指标构成,其中负性情感、生活环境、训练竞赛、人际关系等二级指标对我国运动员主观幸福感有重要影响。竞赛水平的发挥、教练员对运动员的公平性、运动员伤残补偿制度建设、运动队管理方式、运动成绩提升空间等三级指标是影响运动员幸福感的重要外部因素。     

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Abstract

Confirmatory factor analyses (CFAs) were employed to test the factorial validity and structure of the Proactive Coping Inventory (PCI; Greenglass, Schwarzer, Jakubiec, Fiksenbaum, &; Taubert, 1999) in a large multiethnic sample (n=709). CFAs conducted on each individual scale of the PCI supported congeneric measurement. However, when the scales of the PCI were tested simultaneously in a model, a 3-factor model representing Logical Analysis/Problem Solving, Social Support, and Avoidance fit as well as both a 5- and the original 7-factor model. Moreover, strong redundancy among factors of both the 5- and 7-factor models suggested that these models did not represent the PCI well. In addition, multigroup analyses revealed that the parameters (e.g., factor loadings, item intercepts) of the 3-factor model were largely invariant across gender and ethnic groups. Discussion focuses on the interpretability of the 3-factor model of the PCI, and particularly in relation to traditional measures of reactive coping.