Infinitely Adaptive Transition-Metal Ordering in Ln2O2MSe2-Type Oxychalcogenides.

A number of Ln2O2MSe2 (Ln = La and Ce; M = Fe, Zn, Mn, and Cd) compounds, built from alternating layers of fluorite-like [Ln2O2](2+) sheets and antifluorite-like [MSe2](2-) sheets, have recently been reported in the literatures. The available MSe4/2 tetrahedral sites are half-occupied, and different compositions display different ordering patterns: [MSe2](2-) layers contain MSe4/2 tetrahedra that are exclusively edge-sharing (stripe-like), exclusively corner-sharing (checkerboard-like), or mixtures of both. This paper reports 60 new compositions in this family.

Synthesis, structural characterization, and physical properties of the new transition metal oxyselenide Ce2O2ZnSe2.

The quaternary transition metal oxyselenide Ce2O2ZnSe2 has been shown to adopt a ZrCuSiAs-related structure with Zn(2+) cations in a new ordered arrangement within [ZnSe2](2-) layers. The color of the compound changes as a function of cell volume, which can vary by ∼0.4% under different synthetic conditions.

Towards a cognitive model and measure of dissociation.

Dissociation comprises a range of psychological processes, which have largely been the subject of psychodynamic discussion. Dissociative phenomena are for the most part unaddressed by cognitive theorists. Current measures are atheoretical and our understanding of dissociation has been hampered by the absence of clear psychological models.

Threat processing in women with bulimia.

Cognitive-behavioral treatments are the most commonly used approaches for bulimia nervosa. However, these treatments tend to produce only moderate remission rates. Therefore, it is useful to consider how experimental cognitive approaches can help to revise current cognitive-behavioral models of bulimia.