Lifting Epitaxial Graphene by Intercalation of Alkali Metals

We studied the effect of alkali metal intercalation (Cs and Li) on the geometry of graphene on Ir(111) using the X-ray standing waves technique. For both alkali metals, the increase in the mean height of the carbon layer does not depend on the lateral structure or the density of the intercalated layer. For Li, full delamination of graphene from the metal substrate is found already for a small amount of intercalant. Even though lithium lifts graphene to a smaller height, it is much more efficient in ironing out the corrugation of pristine graphene on Ir(111)

Parent- and Teacher-Rated Effectiveness of Cognitive-Behavioral Therapy for Children and Adolescents Under Usual Care Conditions in a University Outpatient Clinic

Compared to randomized controlled trials, studies examining the effectiveness of cognitive behavioral therapy (CBT) in children and adolescents with mental disorders are rare, and a teacher perspective is scarce. The present study investigated the effectiveness of routine CBT in 519 patients aged 6-18years with mental disorders. Changes in mental health problems were assessed in teacher (Teacher Report Form, TRF) and parent rating (Child Behavior Checklist, CBCL) and were analyzed within the total sample, yielding statistically significant, small to medium effect sizes (teacher rating: d=.74-2.39; parent rating: d=.65-1.18). Changes in a subgroup of patients with elevated symptom scores at treatment start were compared to a historical control group receiving weekly academic tutoring. Net total score effect sizes lay between d=0.98 and d=1.29 for teacher rating (parent rating: d=0.84 to d=1.01). Nevertheless, a substantial number of patients remained in the clinical range. Symptom changes during family- and patient-based CBT interventions did not differ from treatments including additional school-based interventions, as was also the case for the comparison of treatments with and without additional pharmacotherapy

Spatial variation of geometry, binding, and electronic properties in the moiré superstructure of MoS 2 on Au(111)

The lattice mismatch between a monolayer of MoS2 and its Au(111) substrate induces a moiré superstructure. The local variation of the registry between sulfur and gold atoms at the interface leads to a periodic pattern of strongly and weakly interacting regions. In consequence, also the electronic bands show a spatial variation. We use scanning tunneling microscopy and spectroscopy (STM/STS), x-ray photoelectron spectroscopy (XPS) and x-ray standing wave (XSW) for a determination of the geometric and electronic structure. The experimental results are corroborated by density functional theory. We obtain the geometric structure of the supercell with high precision, identify the fraction of interfacial atoms that are strongly interacting with the substrate, and analyze the variation of the electronic structure in dependence of the location within the moiré unit cell and the nature of the band

Structure and Growth of Hexagonal Boron Nitride on Ir(111)

Using the X-ray standing wave method, scanning tunneling microscopy, low energy electron diffraction, and density functional theory, we precisely determine the lateral and vertical structure of hexagonal boron nitride on Ir(111). The moire superstructure leads to a periodic arrangement of strongly chemisorbed valleys in an otherwise rather flat, weakly physisorbed plane. The best commensurate approximation of the moire unit cell is (12 X 12) boron nitride cells resting on (11 X 11) substrate cells, which is at variance with several earlier studies. We uncover the existence of two fundamentally different mechanisms of layer formation for hexagonal boron nitride, namely, nucleation and growth as opposed to network formation without nucleation. The different pathways are linked to different distributions of rotational domains, and the latter enables selection of a single orientation only