3,234 research outputs found
Superconducting niobium thin film slow-wave structures
A superconducting comb structure as a slow-wave element in a traveling-wave maser will significantly improve maser noise temperature and gain by reducing the insertion loss. The results of the insertion loss measurements of superconducting niobium slow-wave structures subjected to maser operating conditions at X-Band frequencies are presented
Contact Atomic Structure and Electron Transport Through Molecules
Using benzene sandwiched between two Au leads as a model system, we
investigate from first principles the change in molecular conductance caused by
different atomic structures around the metal-molecule contact. Our motivation
is the variable situations that may arise in break junction experiments; our
approach is a combined density functional theory and Green function technique.
We focus on effects caused by (1) the presence of an additional Au atom at the
contact and (2) possible changes in the molecule-lead separation. The effects
of contact atomic relaxation and two different lead orientations are fully
considered. We find that the presence of an additional Au atom at each of the
two contacts will increase the equilibrium conductance by up to two orders of
magnitude regardless of either the lead orientation or different group-VI
anchoring atoms. This is due to a LUMO-like resonance peak near the Fermi
energy. In the non-equilibrium properties, the resonance peak manifests itself
in a large negative differential conductance. We find that the dependence of
the equilibrium conductance on the molecule-lead separation can be quite
subtle: either very weak or very strong depending on the separation regime.Comment: 8 pages, 6 figure
Optical Spectroscopic Survey of High-latitude WISE-selected Sources
We report on the results of an optical spectroscopic survey at high Galactic latitude (|b| ≥ 30°) of a sample of WISE-selected targets, grouped by WISE W1 (λ_eff = 3.4 μm) flux, which we use to characterize the sources WISE detected. We observed 762 targets in 10 disjoint fields centered on ultraluminous infrared galaxy candidates using DEIMOS on Keck II. We find 0.30 ± 0.02 galaxies arcmin–2 with a median redshift of z = 0.33 ± 0.01 for the sample with W1 ≥ 120 μJy. The foreground stellar densities in our survey range from 0.23 ± 0.07 arcmin–2 to 1.1 ± 0.1 arcmin–2 for the same sample. We obtained spectra that produced science grade redshifts for ≥90% of our targets for sources with W1 flux ≥120 μJy that also had an i-band flux gsim 18 μJy. We used this for targeting very preliminary data reductions available to the team in 2010 August. Our results therefore present a conservative estimate of what is possible to achieve using WISE's Preliminary Data Release for the study of field galaxies
Surface Geometry of C60 on Ag(111)
The geometry of adsorbed C60 influences its collective properties. We report the first dynamical low-energy electron diffraction study to determine the geometry of a C60 monolayer, Ag(111)-(23×23)30°-C60, and related density functional theory calculations. The stable monolayer has C60 molecules in vacancies that result from the displacement of surface atoms. C60 bonds with hexagons down, with their mirror planes parallel to that of the substrate. The results indicate that vacancy structures are the rule rather than the exception for C60 monolayers on close-packed metal surfaces. © 2009 The American Physical Society
The Frequency and Content of Discussions About Alcohol Use in Primary Care and Application of the Chief Medical Officer’s Low-Risk Drinking Guidelines: A Cross-Sectional Survey of General Practitioners and Practice Nurses in the UK
ABSTRACT
Aims: To examine how often General Practitioners (GPs) and Practice Nurses (PNs) working in primary care discuss alcohol with patients, what factors prompt discussions, how they approach patient discussions, and whether the Chief Medical Officer’s (CMO’s) revised low-risk drinking guidelines are appropriately advised.
Methods: Cross-sectional survey with GPs and PNs working in primary care in the UK, conducted January-March 2017 (n=2,020). A vignette exercise examined what factors would prompt a discussion about alcohol, whether they would discuss before or after a patient reported exceeded the revised CMO guidelines (14 units per week), and whether the CMO’s drinking guidelines were appropriately advised. For all patients, participants were asked how often they discussed alcohol and how they approached the discussion (e.g. used screening tool).
Results: The most common prompts to discuss alcohol in the vignette exercise were physical cues (44.7% of participants) or alcohol-related symptoms (23.8%). Most practitioners (70.1%) said they would wait until a patient was exceeding CMO guidelines before instigating discussion. Two-fifths (38.1%) appropriately advised the CMO guidelines in the vignette exercise, with PNs less likely to do so than GPs (OR=0.77, p=0.03). Less than half (44.7%) reportedly asked about alcohol always/often with all patients, with PNs more likely to ask always/often than GPs (OR=2.22, p<0.001). Almost three-quarters said they would enquire by asking about units (70.3%), compared to using screening tools.
Conclusion: Further research is required to identify mechanisms to increase the frequency of discussions about alcohol and appropriate recommendation of the CMO drinking guidelines to patients.This research was supported by funding from Cancer Research UK. JMB is supported by the Medical Research Council (MRC) (Grant MC_UU_12015/4)
Forming Judgments of Attitude Certainty, Intensity, and Importance: The Role of Subjective Experiences
Two studies examined the impact of subjective experiences on reports of attitude certainty, intensity, and importance. In Study 1, participants with moderate or extreme attitudes toward doctor-assisted suicide generated three (easy) or seven (hard) arguments that either supported or countered their opinion toward the issue prior to indicating the strength of their attitude. Participants with moderate attitudes rated their opinions as more intense, personally important, and held with greater certainty when they had generated either a small number of supporting arguments or a large number of opposing arguments. Ratings provided by individuals with extreme attitudes were unaffected by the argument generation task. In Study 2, the impact of ease of recall on strength-related judgments was eliminated when it was rendered nondiagnostic by a misattribution manipulation. Implications of these findings for attitude strength and other judgmental phenomena are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68385/2/10.1177_0146167299025007001.pd
Empathic forecasting: How do we predict other people's feelings?
When making affective forecasts, people commit the impact bias. They overestimate the impact an emotional event has on their affective experience. In three studies we show that people also commit the impact bias when making empathic forecasts, affective forecasts for someone else. They overestimate the impact an emotional event has on someone else's affective experience (Study 1), they do so for friends and strangers (Study 2), and they do so when other sources of information are available (Study 3). Empathic forecasting accuracy, the correlation between one person's empathic forecast and another person's actual affective experience, was lower than between-person forecasting correspondence, the correlation between one person's empathic forecast and another person's affective forecast. Empathic forecasts do not capture other people's actual experience very well but are similar to what other people forecast for themselves. This may enhance understanding between people
- …