Solid-solution strengthening in ordered In x Ga1 − x P alloys

Ordered In _x Ga_{1??? x} P alloys have been grown on to GaAs(001) substrates by metal–organic vapour-phase epitaxy. Lattice-matched compositions of alloys (In _x Ga_{1??? x} P with x?≈?0.5) were used in order to produce epitaxial layers free of structural defects (threading dislocations). Growth temperature and substrate orientation were adjusted to control the degree η, of order, of the alloys in the range 0.3–0.5. Nanoindentation tests were carried out to measure the mechanical response of the heteroepitaxial layers. Transmission electron microscopy was used to characterize the structure as well as the plastic zones generated into the specimen by nanoindentation. Comparison of the alloys with binary references (InP and GaP bare substrates) showed strengthening, with the hardness and flow-stress values that are much larger than those of InP and of the same order of magnitude as those of GaP.     

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.     

Determination of glass-forming ability of Ge1− x Sn x Se2.5 (0 ≤ x ≤ 0.5) alloys using differential scanning calorimetry

The glass-forming ability of Ge_{1? x} Sn _x Se_2.5 (0 ≤ x ≤ 0.5) alloys was studied using differential scanning calorimetry. Samples were scanned at different heating rates under non-isothermal conditions. Various simple quantitative methods were employed to assess the stability of the glassy materials in the above-mentioned system. All of these methods are based on characteristic temperatures, such as the glass-transition temperature, T _g, the onset-of-crystallization temperature, T _c, and the peak crystallization temperature, T _p. A crystallization rate factor, K, has also been used as a measure of the thermal stability of the glasses. It was found that Ge_0.7Sn_0.3Se_2.5 was the least stable among all the samples.     

Effect of network connectivity on thermal properties of As30Te70– x Tl x glasses

Alternating differential scanning calorimetry (ADSC) studies were undertaken to investigate the effect of Tl addition on the thermal properties of As₃₀Te_{70– x} Tl _x (6?≤?x?≤?22 at%) glasses. These include parameters such as glass-transition temperature (T _g), changes in specific heat capacity (ΔC _p) and relaxation enthalpy (ΔH ^NR) at the glass transition. It was found that T _g of the glasses decreased with the addition of Tl, which is in contrast to the dependence of T _g in As–Te glasses on the addition of Al and In. The change in heat capacity ΔC _p through the glass transition was also found to decrease with increasing Tl content. The addition of Tl to the As–Te matrix may lead to a breaking of As–Te chains and the formation of Tl⁺Te^?AsTe_2/2 dipoles. There was no significant dependence of the change of relaxation enthalpy, through the glass transition, with composition.     

Synthesis and evolution of crystalline garnet phases in Y3Sc5– x Ga x O12

Mixed-metal oxides with the composition Y₃Sc _x Ga_{5? x} O₁₂ (x?=?2.0, 2.1, 2.2, 2.25, 2.3, 2.4, 2.5, and 3.0) have been prepared by an aqueous sol–gel method. The effects of scandium substitution on the garnet phase formation were studied by IR spectroscopy and X-ray powder diffraction (XRD). The XRD data indicate that single-phase Y₃Sc _x Ga_{5? x} O₁₂ ceramic samples were obtained for x?=?2.0, 2.1, 2.2, 2.25, 2.3, and 2.4. The results also show that the formation of Y₃Sc _x Ga_{5? x} O₁₂ garnets depends on the molar ratio of scandium and gallium in the investigated composition, and consequently on the mean cationic radius at the Al³⁺ sites. The variation of lattice parameters for the Y₃Sc _x Ga_{5? x} O₁₂ phases with different x is reported.     

Thermal stability and glass-forming ability of Se80− x Te20Ag x (x = 0, 3, 5, 7 and 9) chalcogenide glasses

The thermal stability and glass-forming ability (GFA) of Se_{80? x} Te₂₀Ag _x (x?=?0,?3,?5,?7 and 9) chalcogenide glasses have been investigated using differential scanning calorimetry (DSC). The DSC runs have been taken at five different heating rates (10, 20, 30, 40 and 50?K/min) under non-isothermal condition. The thermal stability and GFA are monitored through determination of the temperature difference ΔT?=?T _c???T _g, where T _c is the onset crystallization temperature, T _g is the glass transition temperature, H ^l is the stability parameter, ΔH _c is the enthalpy released during crystallization and F _i is the fragility index. The activation energy of crystallization E _c and crystallization rate factor K have also been determined as indicators of the thermal stability of the above-mentioned samples. It is found that Se₇₁Te₂₀Ag₉ is the most stable among all the samples of the series.     

Pressure-Induced transitions in amorphous TlxSe100−x alloys

Abstract

The electrical resistivity of bulk semiconducting amorphous Tl_xSe_100?x alloys with 0 ≤ x ≤ 25 has been investigated up to a pressure of 14 GPa and down to liquidnitrogen temperature by use of a Bridgman anvil device. All the glasses undergo a discontinuous pressure-induced semiconducting-to-metal transition. X-ray diffraction studies on the pressure-recovered samples show that the high-pressure phase is the crystalline phase. The pressure-induced crystalline products are identified to be a mixture of Se having a hexagonal structure with a = 4·37 Å and c = 4·95 Å and TlSe having a tetragonal structure with a = 8·0 Å and c = 7·0 Å     

Study of incommensurate modulation in V-doped La2Cu1- x (VO) x O4 + δ by transmission electron microscopy

Structural variations in a hole-rich grain of V-doped La₂Cu_{1? x} (VO) _x O_{4+ δ} (x?=?0.045, δ?=?0.011) superconducting compound have been studied by electron diffraction and high-resolution transmission electron microscopy. Two types of one-dimensional (1-D) incommensurate modulation were observed one after the other when the specimen was exposed to electron beam irradiation. The features of these two modulated structures have been studied and are discussed.     

Stress-corrosion cracking in YBa2Cu3O7−x ceramic superconductor

Abstract

Thin-foil transmission electron microscopy specimens of orthorhombic YBa²Cu³O^7?x subjected to residual elastic strains have shown slow crack growth in an atmosphere with low moisture content. Microcracks, initiated by amorphization at the strained edges, propagate alternately along (110) twin boundaries and (001) stacking faults, where strain energy is accumulated locally. The formation of carbon-rich amorphous layers along the strained lattice planes, followed by residual stress-assisted crack propagation, resembles stress-corrosion cracking in this ceramic superconductor.     

On the meaningfulness of behavior: An expectancy x value approach

Our research examines people’s concept of ‘meaningful behavior’ from an expectancy x value perspective. Specifically, we argue that people consider two elements when inferring the meaningfulness of behavior: the value of the goals that the behavior relates to and the degree to which the behavior is useful for the achievement of these goals. A series of five studies demonstrates that behavior is considered to be ‘meaningful’ if it is highly instrumental for a highly valued goal. Our expectancy x value approach offers a straightforward yet crucial perspective of how people infer whether or not everyday life behaviors are meaningful to them. The implications of our findings for research on meaningfulness, meaning-regulation, and sense making are discussed.     

“2 x 3” primes naming “6”: Evidence from masked priming

It is a common assumption for multiplication-solving models that single-digit multiplications are automatically retrieved. However, the experimental evidence for this is based on paradigms under suspicion. In this research, we employed a new procedure with the aim of assessing the automatic retrieval of multiplication more directly. In two experiments, multiplication automatism was studied using briefly presented primes (stimulus onset asynchrony = 48 msec) in a number-naming task. In Experiment 1, in the congruent conditions, the target and the prime were the same numbers (e.g., prime, 6; target, 6) or the target was the solution to the multiplication prime (e.g., prime, 2×3=; target, 6). In the incongruent conditions, no relationship existed between the primes and the targets (e.g., prime, 32; target, 6; or prime, 4×8=; target, 6). Experiment 2 explored the relevance of the equal sign for the multiplication-priming effect. Data showed that naming was faster when the solution of the multiplication prime matched the target, as compared with the incongruent condition (multiplication-priming effect), and that these effects were found irrespective of the presence of the equal sign. The fact that this priming effect was found even though the participants were unaware of the presentation of the primes supports the automatic character of single-digit multiplication. We conclude by arguing that this procedure is highly valuable for exploring the mechanisms involved in simple arithmetic solving.     

Xunzi and the primitivists on natural spontaneity (xìng 性) and coercion

This article explores two opposing views from Warring States China concerning the value of human natural spontaneity (hereafter xìng 性) and large-scale government coercion. On the one hand, the Ruist (Confucian) philosopher Xunzi championed a comprehensive and coercive ethical, political, and social system or Way (dào 道) that he believed would lead to social order and moral cultivation while opposing people’s xìng. On the other hand, the authors of roughly books 8–10 of Zhuangzi, the primitivists, criticized a Way bearing a striking resemblance to Xunzi’s on the grounds that it seriously harms people by opposing their xìng. I argue that the primitivists offer compelling reasons for Xunzi to modify his own Way regarding its relationship with xìng, though their own proposed alternative Way is not very attractive. I conclude with a brief discussion of one primitivist-inspired alternative view found in the Lü Shi Chun Qiu, which plausibly suggests that one way of respecting people’s xìng is by offering them opportunities to explore their natural abilities.     

Demonstration of the g · b x u = 0 edge dislocation invisibility criterion for electron channelling contrast imaging

Dislocations with a large edge component do not exhibit a full loss of diffraction contrast in the transmission electron microscope unless the conditions g b = 0 and g b x u = 0 are simultaneously met. Because of a similarity between transmission electron microscopy (TEM) diffraction contrast and electron channelling contrast in the scanning electron microscope, the same contrast rules would be expected to apply for electron channelling contrast imaging (ECCI). Using the characteristic edge dislocations formed in annealed FeAl, it is demonstrated that the same extinction conditions apply for TEM diffraction contrast and ECCI.     

Feminine Gender Role Discrepancy Strain and Women’s Self-Esteem in Daily and Weekly Life: A Person x Context Perspective

Sex Roles - Social pressures to adhere to traditional feminine roles may place some women at risk of experiencing gender role discrepancy strain, when they behave, think, or feel in ways discrepant...     

Interacción persona x situación en la predicción de la personalidad: algunas especificaciones del factor personal

RESUMEN

Este trabajo intenta determinar si la multidimensionalidad de la Ansiedad-rasgo (A-trait), medida por el S-R GTA (Inventario E-R del Rasgo General de Ansiedad) está referida a diferentes perfiles de personalidad. Los resultados del análisis de regresión lineal múltiple usando la escala de “Locus of Control” interno-externo, el Inventario Psicológico de California, la Escala de Confianza interpersonal, como medidas predictivas, confirmaron la existencia de diversos perfiles de personalidad para una de las cuatro facetas de la Ansiedad-rasgo. Estos hallazgos atestiguan la multidimensionalidad del Inventario E-R del Rasgo General Ansiedad y la importancia de especificar la situación en la medida de la Ansiedad.     

Who took the "x" out of expectancy-value theory? A psychological mystery, a substantive-methodological synergy, and a cross-national generalization

Expectancy-value theory (EVT) is a dominant theory of human motivation. Historically, the Expectancy × Value interaction, in which motivation is high only if both expectancy and value are high, was central to EVT. However, the Expectancy × Value interaction mysteriously disappeared from published research more than 25 years ago. Using large representative samples of 15-year-olds (N = 398,750) from 57 diverse countries, we attempted to solve this mystery by testing Expectancy × Value interactions using latent-variable models with interactions. Expectancy (science self-concept), value (enjoyment of science), and the Expectancy × Value interaction all had statistically significant positive effects on both engagement in science activities and intentions of pursuing scientific careers; these results were similar for the total sample and for nearly all of the 57 countries considered separately. This study, apparently the strongest cross-national test of EVT ever undertaken, supports the generalizability of EVT predictions--including the "lost" Expectancy × Value interaction.     

Does solution of mental arithmetic problems such as 2 + 6 and 3 x 8 rely on the process of "Memory updating"?

Two experiments are reported that used the selective interference paradigm to study whether, besides response selection, the process of memory updating is involved in simple mental arithmetic. Participants were asked to solve simple sums (e.g., 2 + 6, Experiment 1) or simple products (e.g., 3 X 8, Experiment 2) in a single-task control condition and in three dual-task conditions with a selective interference task, simple reactions, choice reactions, or delayed choice reactions. The role of memory updating was estimated on the basis of the difference in impairment due to the choice reaction time and the delayed choice reaction time task, whereas the difference in impairment between the simple reaction time and the choice reaction time task indicates the role of response selection. While replicating previous results concerning response selection (Deschuyteneer & Vandierendonck, 2005, in press), the study showed that memory updating is strongly involved in solving simple mental arithmetic sums and products.