Nanocomposite-like structure in an epitaxial CaCu3Ti4O12 film on LaAlO3 (001)

We report the detailed microstructural study of a CaCu₃Ti₄O₁₂ (CCTO) thin film using transmission electron microscopy (TEM). The CCTO thin film studied in this work was deposited on a (001)-oriented LaAlO₃ (LAO) substrate by pulsed-laser ablation and has a high dielectric constant of about 10⁴ at 1?MHz at room temperature; however, the mechanism for such a dielectric property is not yet understood. Plan-view TEM studies show that the CCTO samples have orthogonal domain structures with the edge nearly parallel to either the [100] or the [010] direction of the CCTO. A minor anatase TiO₂ phase was found at the domain boundaries. The CCTO and the TiO₂ phases are separated by an amorphous-like layer that has a thickness of several nanometres. Cross-sectional TEM studies reveal that both CCTO and TiO₂ in the films are c axis oriented with a very sharp interface to the LAO-(001) substrate and possess a unique crystallographic orientation relationship of (001) _CCTO //(001)_{TiO 2} //(001) _LAO and [100] _CCTO //[100] _{TiO 2} //[100] _LAO. The Rutherford back-scattering ion chanelling studies suggest a composition of Ca_1.5Cu₃Ti_5.5O₁₆ for the film, in which the extra calcium, titanium and oxygen form the anatase TiO₂ phase and amorphous calcium oxide layer that separates the CCTO and TiO₂ phases. Such nanocomposite-like structures may provide an important clue to the mechanism of the dielectric property of these films.     

3D shape and orientation of nanoscale Pb inclusions at grain boundaries in Al observed by TEM and STEM tomography

We have combined high-angle annular dark field/scanning transmission electron microscopy (HAADF-STEM) tomography with bright field (BF)-TEM tomography to characterize small inclusions of Pb at a grain boundary in Al. It was found that the shape of the grain boundary inclusions is more complex than previously thought. By using moiré fringes observed at some orientations of the specimen in a BF-TEM tomographic tilt series, we were able to determine the orientation of each grain, the axis and angle of misorientation of the grain boundary, and the facet planes of the grain boundary inclusions. The 3D shape of the inclusions was determined by merging this information with the HAADF-STEM tomography.     

Composition dependence of the activation energy of the glass transition in some chalcogenide glasses

The activation energy (E _t) of the glass transition process has been obtained for glassy Se_{80? x} Te₂₀M _x (M = Ag, Cd, In, Sb) and Se_{100? x} M _x (M = In, Te, Sb) systems using differential scanning calorimetry. The composition dependence of E _t is explained in terms of fragility index for the systems. A reversal in the trend of the E _t is explained using topological models.     

On the glass transition temperature and the elastic properties in Zr-based bulk metallic glasses

The temperature dependence of the elastic moduli was estimated from ultrasound time of flight measurements performed on bulk metallic glasses of composition Zr_{63? x} Cu₂₄Al _x Ni₁₀Co₃. Using the corresponding values at the glass transition temperature, the local atomic strain was determined. The obtained values for the critical atomic strain calculated for 8 at%?<?x?<?15 at% are close to the predicted universal criterion derived from a topological model, but may also reflect the difference in the chemical interaction that are not accounted by a topological approach.     

Investigations of the optical spectra and local structure for nickel(II) ions in XF2 (X = Mg,Zn) single crystals

A complete diagonalization energy matrix method (CDM) is proposed for 3d ⁸ ions in orthorhombic site (D _{2 h} ) symmetry. As an application, the optical spectra of XF₂ : Ni²⁺ (X = Mg, Zn) is well explained on the basis of both the CDM and the semi-self-consistent field d-orbital (semi-SCF d-orbital) theory. In addition, by establishing the relationship between the optical spectra and local structure, it has been possible to calculate the crystal structure parameters for XF₂:Ni²⁺ from optical measurements on Ni²⁺ ions. The theoretical results are in good agreement with experimental findings.     

Ethical issues in the publication of clinical material

Some of the ethical issues involved in publishing clinical material are considered. These include the 'ownership' of such material, the responsibilities of the analyst towards patients and professional colleagues, the keeping and status of records, the nature of trust and confidentiality and its place in analysis, the question of obtaining consent for publication, the nature of consent, and its consequences for treatment. The issues of disguise, of authenticity, and of accuracy are also touched on, as is the potential role of the author's anonymity in protecting the anonymity of the patient.     

From ultrafast to slow: Heating rate dependence of the glass transition temperature in metallic systems

When a solid crosses the glass transition, viscous flow sets in and the glass transforms into a supercooled liquid. The glass transition temperature exhibits a heating rate dependence which was previously observed to follow a Vogel–Fulcher–Tammann (VFT) equation. Here we report on a change in the heating rate dependence of the glass transition, determined by the distinct increase in the specific heat capacity, of a metallic glass. We combine standard techniques such as differential scanning calorimetry with recently developed ohmic heating techniques in order to cover seven orders of magnitude in heating rate. Contrary to previous reports, our results show that the change of the glass transition temperature cannot be described by a single VFT equation. Instead we find two distinct regimes which independently follow a VFT expression.     

Collaborative scholarly communities and access in the study of material and visual cultures of religion

The Center for the Study of Material and Visual Cultures of Religion at Yale University (MAVCOR) does not simply, or even most fundamentally, shape a physical center at Yale University. Although MAVCOR organizes events at Yale and coordinates project cycles involving Yale affiliates as well as scholars from other universities in the United States and around the world, much of MAVCOR’s activity is conducted online. MAVCOR publishes a born-digital, open-access double-blind peer-reviewed journal, MAVCOR Journal. It also features a born-digital exhibition space, the Material Objects Archive. In at least two ways, MAVCOR is deliberately interstitial, invested in the connective spaces between both disciplines and technologies. First, the Center emerged from a desire to promote interdisciplinary conversation among scholars of religion, art history, anthropology, and others engaged with our subjects of inquiry. We have aimed to accomplish this goal by shaping a forum for conversation and an archive for mutual use. Second, MAVCOR engages the need to form a space for peer-reviewed content online in a manner that emphasizes the mutually beneficial relationship of print and digital modes of inquiry. In this work, MAVCOR’s overarching commitment is to promote innovative, substantively researched, thoughtfully constructed scholarship, with robust interdisciplinarity as a fundamental element of form and content.     

Reassessing the 3/4 view effect in face recognition

It is generally accepted that unfamiliar faces are better recognized if presented in 3/4 view. A common interpretation of this result is that the 3/4 view represents a canonical view for faces. This article presents a critical review of this claim. Two kinds of advantage, in which a 3/4 view either generalizes better to a different view or produces better recognition in the same view, are discussed. Our analysis of the literature shows that the first effect almost invariably depended on different amounts of angular rotation that was present between learning and test views. The advantage usually vanished when angular rotation was equalized between conditions. Reports in favor of the second effect are scant and can be countered by studies reporting negative findings. To clarify this ambiguity, we conducted a recognition experiment. Subjects were trained and tested on the same three views (full-face, 3/4 and profile). The results showed no difference between the three view conditions. Our analysis of the literature, along with the new results, shows that the evidence for a 3/4 view advantage in both categories is weak at best. We suggest that a better predictor of performance for recognition in different views is the angular difference between learning and test views. For recognition in the same view, there may be a wide range of views whose effectiveness is comparable to the 3/4 view.     

Investigations of the optical spectra and EPR g-factors for the tetragonal Ce3+ centers in YPO4 and LuPO4 crystals

The optical spectral band positions and EPR g-factors (g_‖ , g _⊥) for the tetragonal Ce³⁺ centers in YPO₄ and LuPO₄ crystals with the zircon-structure are calculated using a complete diagonalization (of the energy matrix) method (CDM) related to 4f¹ ions in tetragonal symmetry. In this method, the Zeeman interaction term are added to the Hamiltonian in the conventional CDM and so no perturbation calculations are required to obtain the g factors. The crystal-field parameters used in the calculations are obtained from the superposition model in which the local lattice relaxation related to the bonding lengths is considered. The calculated results are in reasonable agreement with the experimental values. It is found that the four observed optical bands for both the systems can be attributed to Ce³⁺ ions in a tetragonal crystal field.     

The executive demands of strategic reasoning are modified by the way in which children are prompted to think about the task: Evidence from 3- to 4-year-olds

We investigated a test of strategic reasoning (the Windows task) that in different studies has yielded contrasting pictures of young children's executive abilities [Russell, J., Mauthner, N., Sharpe, S., & Tidswell, T. (1991). The “windows task” as a measure of strategic deception in preschoolers and autistic subjects. British Journal of Developmental Psychology, 9, 331–349; Samuels, M. C., Brooks, P. J., & Frye, D. (1996). Strategic game playing through the windows task. British Journal of Developmental Psychology, 14, 159–172]. An experiment with 52 three- to four-year-olds showed robust effects of different wordings for the prompts used to ask children to respond, and found that a single exposure to the facilitating wording led to improved performance on subsequent trials where the standard wording was used. This suggests that the effect of the wording was to help children infer an appropriate basis for responding, and not to reduce the trial-by-trial working memory or inhibitory demands of the task.