Experimental investigations of TB2 alloy by pack boriding with rare-earth oxides

ABSTRACT

An orthogonal test with four factors, namely temperature, time, type of rare-earth oxides (REOs) and REO content, was performed to obtain the optimised boriding parameters of TB2 alloy by pack boriding with REOs. It is found that temperature has the strongest effect on the boride layer thickness, while time has the strongest effect on the surface hardness and coefficient of friction. The optimum parameters for pack boriding of TB2 alloy with REO are a temperature of 1373?K, a time of 20?h, La₂O₃ as the REO with a content of 4?wt.%.     

Superconductivity in Ca-intercalated bilayer graphene

Recent observation of proximity effect [H.B. Heersche, P. Jarillo-Herrero, J.B. Oostinga, L.M.K. Vandersypen, and A.F. Morpurgo, Nature, bf 446 (2007) p. 05555.] has ignited interest in superconductivity in graphene and its derivatives. We consider Ca-intercalated graphene bilayer and argue that it is a superconductor, and likely with a sizeable T _c . We find substantial and suggestive similarities between Ca-intercalated bilayer (C₆CaC₆), and CaC₆, an established superconductor with T _c = 11.5 K. In particular, the nearly free electron band, proven to be instrumental for superconductivity in intercalated graphites, does cross the chemical potential in (C₆CaC₆), despite the twice smaller doping level, satisfying the so-called “Cambridge criterion”. Calculated properties of zone-center phonons are very similar to those of CaC₆. This suggests that the critical temperature would probably be on the same scale as in CaC₆.     

An adaptive perspective on revealed and concealed cues to empathy

Wu, Sheppard, and Mitchell (Br. J. Psychol., 2016; 107, 1‐22) found that observers could accurately identify people with extreme but not more average empathy scores. Here, we further consider this U‐shaped discrimination function. We first examine a statistical issue regarding the construction of the average groups, which are less homogenous by definition than the extreme groups. We then consider the kinds of questions arising when these results are considered within the adaptive framework of signal theory. Some interesting questions arise relating to the signal sender, including the costs and benefits to the sender in revealing and concealing true empathy levels, and the effects of adopting behavioural norms to conceal true levels of empathy.     

Fragmentation testing for ductile thin films on polymer substrates

Fragmentation testing of thin films on substrates has in the past been mostly performed in situ using optical and scanning electron microscopy. While these techniques work well for brittle materials, they cannot always discern the difference between through-thickness cracks (TTCs) and localized plastic deformation of ductile films. Here, we describe fragmentation testing with atomic force microscopy and present criterion to distinguish TTCs and localized deformation for ductile films.     

Electrical properties of thin films of a-Ga x Te100− x composed of nanoparticles

Thin films of Ga _x Te_{100? x} (x?=?3, 6, 9 and 12) have been synthesized by thermal evaporation. From SEM images, it is observed that all the films contain nanoparticles of sizes varying from 100 to 200?nm. The dc electrical conductivity of the as-deposited films of Ga _x Te_100?x nanoparticles is measured as a function of temperature range from 298 to 383?K, and increases exponentially with temperature. The value of the activation energy, calculated from the slope of ln?σ _dc versus 1000/T plots, is found to decrease with increase in the Ga content. On the basis of the value of the pre-exponential factor σ _o, it is suggested that the conduction is due to thermally assisted tunneling of carriers in localized states near the band edges. The optical measurements suggest an indirect optical band gap in this system. The value of the optical band gap decreases on increasing the Ga concentration.     

A novel lattice correspondence of B19 → B19′ transformation in Ti–Ni–Cu shape memory alloy thin film

In this study, we found a novel lattice correspondence of the B19–B19′ transformation in a Ti–Ni–Cu thin film: (1?1?1)_B19′//(0?0?1)_B19, [0, 1, 1]_B19′//[1?0?0]_B19. Near the coarse precipitate and the grain boundaries, the B19′ martensite forms with the novel lattice correspondence to product the (1?1?1) type I twinning instead of the usual (0?0?1) compound twinning. Crystallographic analyses show that the novel lattice correspondence results from the local stress concentration.     

Body dissatisfaction,eating disorders,and depression: A developmental perspective

McCarthy (1990) contends that a cultural ideal of thinness (the thin ideal) causes depression and eating disorders to occur more frequently in women than men. She believes eating disorders are a way of coping with depression and hypothesizes that the thin ideal has its greatest impact during puberty when sexual attractiveness becomes important and changes in physical appearance increase the discrepancy between the adolescent girl's actual and ideal body image. The present study used a cross-sectional design of 5th, 8th, and 12th grade males and females (N = 599) to test several predictions from McCarthy's model. As expected, 8th and 12th grade females preferred a thinner than average body shape. They were more dissatisfied with their bodies than males and scored higher on measures of disordered eating. In contrast, before puberty (5th grade) boys were more depressed than their female peers but this pattern was reversed in 8th grade boys and girls. Paralleling changes in depression, disordered eating scores were highest in 8th and 12th grade girls. Both of these findings underscore the role of maturational factors in the onset of eating disorders. Although the sample was ethnically diverse and mainly from middle and low socioeconomic groups, there was a surprisingly high incidence of body dissatisfaction and symptoms of disordered eating. This illustrates the pervasiveness of thinness as a standard of feminine beauty in our society and the damaging effects it can have.     

Speed-Dating

ABSTRACT— Scholars have recently begun to harness the immense power of speed-dating procedures to achieve important and novel insights into the dynamics of romantic attraction. Speed-dating procedures allow researchers to study romantic dynamics dyadically, with regard to potentially meaningful relationships, and with strong external validity. This article highlights the strengths and promise of speed-dating procedures, reviews some of their most exciting contributions to our understanding of the social psyche, and illustrates how scholars can employ speed-dating and its straightforward variants to study topics relevant to diverse subfields of psychological science.