OXYGEN K

The O K spectra of these 3 products, at -160 Deg, show a prominent peak at 532 eV. In ice and solid MeOH, the principal peak occurs at 526 eV. The ice spectrum has also a well-defined subpeak at 520 eV; it is due to a transition from 1 of the MO. The main band and also the subpeak are broader in MeOH than in ice. The transition at 526 eV results from a 1b1 nonbonding orbital (2pp lone pair) and thus can be called an ionic transition. The O subband at 520 eV stems from a 1b2 bonding orbital (2ps type). The spectrum from solidified CO2 also shows 2 peaks, at 527 and 523 eV, the former one being an ionic peak. EtOH, PrOH, and BuOH yield spectra indistinguishable from that of MeOH

Attention bias dynamics and symptom severity during and following CBT for social anxiety disorder

Objective: Threat-related attention bias figures prominently in contemporary accounts of the maintenance of anxiety disorders, yet longitudinal intervention research relating attention bias to anxiety symptom severity is limited. Capitalizing on recent advances in the conceptualization and measurement of attention bias, we aimed to examine the relation between attention bias, indexed using trial-level bias scores (TLBSs) to quantify temporal dynamics reflecting dysregulation of attentional processing of threat (as opposed to aggregated mean bias scores) and social anxiety symptom severity over the course of cognitive-behavioral therapy (CBT) and 1-month follow-up. Method: Adults with social anxiety disorder (N = 39) assigned to either yohimbine-or placebo-augmented CBT completed measures of attention bias and social anxiety symptom severity weekly throughout CBT (5 sessions) and at 1-week and 1-month posttreatment. Results: TLBSs of attention bias temporal dynamics showed stronger psychometric properties than mean aggregated scores and were highly interrelated, in line with within-subject temporal variability fluctuating in time between attentional overengagement and strategic avoidance from threat. Attention bias toward threat and temporal variability in attention bias (i.e., attentional dysregulation), but not attention bias away from threat, significantly reduced over the course of CBT. Cross-lag analyses revealed no evidence of a causal relation between reductions in attentional dysregulation leading to symptom severity reduction, or vice versa. Observed relations did not vary as a function of time. Conclusions: We found no evidence for attentional dysregulation as a causal mechanism for symptom reduction in CBT for social anxiety disorders. Implications for future research are discussed

Tendency Bias Correction in Coupled and Uncoupled Global Climate Models with a Focus on Impacts over North America

We revisit the bias correction problem in current climate models, taking advantage of state-of-the-art atmospheric reanalysis data and new data assimilation tools that simplify the estimation of short-term (6 hourly) atmospheric tendency errors. The focus is on the extent to which correcting biases in atmospheric tendencies improves the models climatology, variability, and ultimately forecast skill at subseasonal and seasonal time scales. Results are presented for the NASA GMAO GEOS model in both uncoupled (atmosphere only) and coupled (atmosphereocean) modes. For the uncoupled model, the focus is on correcting a stunted North Pacific jet and a dry bias over the central United States during boreal summerlong-standing errors that are indeed common to many current AGCMs. The results show that the tendency bias correction (TBC) eliminates the jet bias and substantially increases the precipitation over the Great Plains. These changes are accompanied by much improved (increased) storm-track activity throughout the northern midlatitudes. For the coupled model, the atmospheric TBCs produce substantial improvements in the simulated mean climate and its variability, including a much reduced SST warm bias, more realistic ENSO-related SST variability and teleconnections, and much improved subtropical jets and related submonthly transient wave activity. Despite these improvements, the improvement in subseasonal and seasonal forecast skill over North America is only modest at best. The reasons for this, which are presumably relevant to any forecast system, involve the competing influences of predictability loss with time and the time it takes for climate drift to first have a significant impact on forecast skill

Theory of spin-orbit coupling in bilayer graphene

Theory of spin-orbit coupling in bilayer graphene is presented. The electronic band structure of the AB bilayer in the presence of spin-orbit coupling and a transverse electric field is calculated from first-principles using the linearized augmented plane wave method implemented in the WIEN2k code. The first-principles results around the K points are fitted to a tight-binding model. The main conclusion is that the spin-orbit effects in bilayer graphene derive essentially from the single-layer spin-orbit coupling which comes almost solely from the d orbitals. The intrinsic spin-orbit splitting (anticrossing) around the K points is about 24\mu eV for the low-energy valence and conduction bands, which are closest to the Fermi level, similarly as in the single layer graphene. An applied transverse electric field breaks space inversion symmetry and leads to an extrinsic (also called Bychkov-Rashba) spin-orbit splitting. This splitting is usually linearly proportional to the electric field. The peculiarity of graphene bilayer is that the low-energy bands remain split by 24\mu eV independently of the applied external field. The electric field, instead, opens a semiconducting band gap separating these low-energy bands. The remaining two high-energy bands are spin-split in proportion to the electric field; the proportionality coefficient is given by the second intrinsic spin-orbit coupling, whose value is 20\mu eV. All the band-structure effects and their spin splittings can be explained by our tight-binding model, in which the spin-orbit Hamiltonian is derived from symmetry considerations. The magnitudes of intra- and interlayer couplings---their values are similar to the single-layer graphene ones---are determined by fitting to first-principles results.Comment: 16 pages, 13 figures, 5 tables, typos corrected, published versio

Preparation and properties of amorphous MgB2_2/MgO superstructures: A new model disordered superconductor

In this paper we introduce a novel method for fabricating MgB$_2$/MgO multilayers and demonstrate the potential for using them as a new model for disordered superconductors. In this approach we control the annealing of the MgB$_2$ to yield an interesting new class of disordered (amorphous) superconductors with relatively high transition temperatures. The multilayers appear to exhibit quasi-two-dimensional superconductivity with controlled anisotropy. We discuss the properties of the multilayers as the thickness of the components of the bilayers vary.Comment: 7 pages, 8 figure

Imaging Pulsed Laser Deposition oxide growth by in-situ Atomic Force Microscopy

To visualize the topography of thin oxide films during growth, thereby enabling to study its growth behavior quasi real-time, we have designed and integrated an atomic force microscope (AFM) in a pulsed laser deposition (PLD) vacuum setup. The AFM scanner and PLD target are integrated in a single support frame, combined with a fast sample transfer method, such that in-situ microscopy can be utilized after subsequent deposition pulses. The in-situ microscope can be operated from room temperature (RT) up to 700$^\circ$C and at (process) pressures ranging from the vacuum base pressure of 10$^{-6}$ mbar up to 1 mbar, typical PLD conditions for the growth of oxide films. The performance of this instrument is demonstrated by resolving unit cell height surface steps and surface topography under typical oxide PLD growth conditions.Comment: 8 pages, 8 figure

Electronic coupling between Bi nanolines and the Si(001) substrate: An experimental and theoretical study

Atomic nanolines are one dimensional systems realized by assembling many atoms on a substrate into long arrays. The electronic properties of the nanolines depend on those of the substrate. Here, we demonstrate that to fully understand the electronic properties of Bi nanolines on clean Si(001) several different contributions must be accounted for. Scanning tunneling microscopy reveals a variety of different patterns along the nanolines as the imaging bias is varied. We observe an electronic phase shift of the Bi dimers, associated with imaging atomic p-orbitals, and an electronic coupling between the Bi nanoline and neighbouring Si dimers, which influences the appearance of both. Understanding the interplay between the Bi nanolines and Si substrate could open a novel route to modifying the electronic properties of the nanolines.Comment: 6 pages (main), 2 pages (SI), accepted by Phys. Rev.

Confined coherence and analytic properties of Green's functions

A simple model of noninteracting electrons with a separable one-body potential is used to discuss the possible pole structure of single particle Green's functions for fermions on unphysical sheets in the complex frequency plane as a function of the system parameters. The poles in the exact Green's function can cross the imaginary axis, in contrast to recent claims that such a behaviour is unphysical. As the Green's function of the model has the same functional form as an approximate Green's function of coupled Luttinger liquids no definite conclusions concerning the concept of "confined coherence" can be drawn from the locations of the poles of this Green's function.Comment: 3 pages, 3 figure

Does perceived support in employee development affect personnel turnover?

This article focuses on whether it is beneficial for firms to invest in the general skills of their workforce or whether these training investments merely encourage personnel turnover. Estimation results derived from a sample of 2833 dutch pharmacy assistants show that participation in general training does not induce employees' intention to quit, as predicted by human capital theory. We find that a firm's investments in general training significantly contribute to the perceived support in employee development (psed) among the workforce, as predicted by social exchange theory. Moreover, we show that psed is negatively related to employees' intention to quit the firm; however, this effect is to a large extent mediated by employee job satisfaction. Our findings support the importance of social exchange theory in explaining turnover behaviour as a consequence of personnel development practices