6,198 research outputs found
Thermodynamics of rotating Bose gases in a trap
Novel ground state properties of rotating Bose gases have been intensively
studied in the context of neutral cold atoms. We investigate the rotating Bose
gas in a trap from a thermodynamic perspective, taking the charged ideal Bose
gas in magnetic field (which is equivalent to a neutral gas in a synthetic
magnetic field) as an example. It is indicated that the Bose-Einstein
condensation temperature is irrelevant to the magnetic field, conflicting with
established intuition that the critical temperature decreases with the field
increasing. The specific heat and Landau diamagnetization also exhibit
intriguing behaviors. In contrast, we demonstrate that the condensation
temperature for neutral Bose gases in a rotating frame drops to zero in the
fast rotation limit, signaling a non-condensed quantum phase in the ground
state.Comment: 4 pages, 1 figur
Comparison of O-RADS with the ADNEX model and IOTA SR for risk stratification of adnexal lesions: a systematic review and meta-analysis
PurposeThis study aims to systematically compare the diagnostic performance of the Ovarian-Adnexal Reporting and Data System with the International Ovarian Tumor Analysis Simple Rules and the Assessment of Different NEoplasias in the adneXa model for risk stratification of ovarian cancer and adnexal masses.MethodsA literature search of online databases for relevant studies up to July 2023 was conducted by two independent reviewers. The summary estimates were pooled with the hierarchical summary receiver-operating characteristic model. The quality of the included studies was assessed with the Quality Assessment of Diagnostic Accuracy Studies–2 and the Quality Assessment of Diagnostic Accuracy Studies-Comparative Tool. Metaregression and subgroup analyses were performed to explore the impact of varying clinical settings.ResultsA total of 13 studies met the inclusion criteria. The pooled sensitivity and specificity for eight head-to-head studies between the Ovarian-Adnexal Reporting and Data System and the Assessment of Different NEoplasias in the adneXa model were 0.96 (95% CI 0.92–0.98) and 0.82 (95% CI 0.71–0.90) vs. 0.94 (95% CI 0.91–0.95) and 0.83 (95% CI 0.77–0.88), respectively, and for seven head-to-head studies between the Ovarian-Adnexal Reporting and Data System and the International Ovarian Tumor Analysis Simple Rules, the pooled sensitivity and specificity were 0.95 (95% CI 0.93–0.97) and 0.75 (95% CI 0.62–0.85) vs. 0.91 (95% CI 0.82–0.96) and 0.86 (95% CI 0.76–0.93), respectively. No significant differences were found between the Ovarian-Adnexal Reporting and Data System and the Assessment of Different NEoplasias in the adneXa model as well as the International Ovarian Tumor Analysis Simple Rules in terms of sensitivity (P = 0.57 and P = 0.21) and specificity (P = 0.87 and P = 0.12). Substantial heterogeneity was observed among the studies for all three guidelines.ConclusionAll three guidelines demonstrated high diagnostic performance, and no significant differences in terms of sensitivity or specificity were observed between the three guidelines
Crystal Structure Manipulation of the Exchange Bias in an Antiferromagnetic Film
Exchange bias is one of the most extensively studied phenomena in magnetism,
since it exerts a unidirectional anisotropy to a ferromagnet (FM) when coupled
to an antiferromagnet (AFM) and the control of the exchange bias is therefore
very important for technological applications, such as magnetic random access
memory and giant magnetoresistance sensors. In this letter, we report the
crystal structure manipulation of the exchange bias in epitaxial hcp Cr2O3
films. By epitaxially growing twined (10-10) oriented Cr2O3 thin films, of
which the c axis and spins of the Cr atoms lie in the film plane, we
demonstrate that the exchange bias between Cr2O3 and an adjacent permalloy
layer is tuned to in-plane from out-of-plane that has been observed in (0001)
oriented Cr2O3 films. This is owing to the collinear exchange coupling between
the spins of the Cr atoms and the adjacent FM layer. Such a highly anisotropic
exchange bias phenomenon is not possible in polycrystalline films.Comment: To be published in Scientific Reports, 12 pages, 6 figure
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