1,266 research outputs found
CMCE at SemEval-2020 Task 1: Clustering on Manifolds of Contextualized Embeddings to Detect Historical Meaning Shifts
Intrinsic Tunneling in Cuprates and Manganites
The most anisotropic high temperature superconductors like Bi2Sr2CaCu2O8, as
well as the recently discovered layered manganite La1.4Sr1.6Mn2O7 are layered
metallic systems where the interlayer current transport occurs via sequential
tunneling of charge carriers. As a consequence, in Bi2Sr2CaCu2O8 adjacent CuO2
double layers form an intrinsic Josephson tunnel junction while in in
La1.4Sr1.6Mn2O7 tunneling of spin polarized charge carriers between adjacent
MnO2 layers leads to an intrinsic spin valve effect. We present and discuss
interlayer transport experiments for both systems. To perform the experiments
small sized mesa structures were patterned on top of single crystals of the
above materials defining stacks of a small number of intrinsic Josephson
junctions and intrinsic spin valves, respectively.Comment: 6 pages, 8 figure
Charge-imbalance effects in intrinsic Josephson systems
We report on two types of experiments with intrinsic Josephson systems made
from layered superconductors which show clear evidence of nonequilibrium
effects: 1. In 2-point measurements of IV-curves in the presence of high-
frequency radiation a shift of the voltage of Shapiro steps from the canonical
value hf/(2e) has been observed. 2. In the IV-curves of double-mesa structures
an influence of the current through one mesa on the voltage measured on the
other mesa is detected. Both effects can be explained by charge-imbalance on
the superconducting layers produced by the quasi-particle current, and can be
described successfully by a recently developed theory of nonequilibrium effects
in intrinsic Josephson systems.Comment: 8pages, 9figures, submitted to Phys. Rev.
Image Co-localization by Mimicking a Good Detector's Confidence Score Distribution
Given a set of images containing objects from the same category, the task of
image co-localization is to identify and localize each instance. This paper
shows that this problem can be solved by a simple but intriguing idea, that is,
a common object detector can be learnt by making its detection confidence
scores distributed like those of a strongly supervised detector. More
specifically, we observe that given a set of object proposals extracted from an
image that contains the object of interest, an accurate strongly supervised
object detector should give high scores to only a small minority of proposals,
and low scores to most of them. Thus, we devise an entropy-based objective
function to enforce the above property when learning the common object
detector. Once the detector is learnt, we resort to a segmentation approach to
refine the localization. We show that despite its simplicity, our approach
outperforms state-of-the-art methods.Comment: Accepted to Proc. European Conf. Computer Vision 201
A Tree-Ring Record of Historical Fire Activity In a Piedmont Longleaf Pine (\u3ci\u3ePinus palustris\u3c/i\u3e Mill.) Woodland In North Carolina, USA
CO2 capture from industrial point source waste streams represents an important need for achieving the global goal of carbon-neutrality. Compared with conventional liquid sorbents, solid sorbents can exhibit several distinct advantages, including enhanced lifetime and reduced energy consumption for sorbent regeneration. Considering that reducing CO2 emission is a great challenge, reaching approximately 37 billion metric tons just in 2021, ideal sorbent solutions should not only exhibit a high capture performance but also enable large scale manufacturing using low-cost precursors and simple processes. In this work, we demonstrate the use of a commodity polymer, polystyrene-block-polyisoprene-block-polystyrene (SIS), as the starting material for preparing hierarchically porous, sulfur-doped carbons for CO2 capture. Particularly, the sulfonation-crosslinking reaction enables the formation of macropores in the polymer framework due to the release of gaseous byproducts. After carbonization and activation, the highly porous structure of SIS-derived carbons is successfully retained, while their surface area can reach up to 905 m2 gâ1. These porous carbon sorbents exhibit excellent CO2 uptake performance, reaching sorption capacities of 3.8 mmol gâ1 at 25 °C and 6.0 mmol gâ1 at 0 °C, as well as a high selectivity up to 43â:â1 against N2 gas under ambient conditions. Overall, our work provides an industrially viable method for âtemplate-freeâ fabrication of porous carbons from commodity polyolefin-based materials, which can be employed for reducing CO2 emission from industrial plants/sectors
Buddy Study: Partners for better health in adolescents with type 2 diabetes
AIM: To investigate whether assigning young, healthy and motivated lay volunteer partners (âbuddiesâ) to adolescents with type 2 diabetes improves hemoglobin A1c (HbA1c).
METHODS: Adolescents with type 2 diabetes were randomized to partnering with a âbuddyâ or to conventional treatment. During the initial screening visit, which coincided with a routine outpatient diabetes clinic visit, patients with type 2 diabetes underwent a physical examination, detailed medical history, laboratory measurement of HbA1c, and completed two questionnaires (Pediatric Quality of Life Inventory and Childrenâs Depression Inventory) to assess their overall quality of life and the presence of depressive symptoms. Patients were then randomized to the intervention (the buddy system) or conventional treatment (standard care). All patients were scheduled to return for follow-up at 3- and 6-mo after their initial visit. HbA1c was determined at all visits (i.e., at screening and at the 3- and 6-mo follow-up visits) and quality of life and depressive symptoms were evaluated at the screening visit and were reassessed at the 6-mo visit.
RESULTS: Ten adolescents, recruited from a pool of approximately 200 adolescents, enrolled over a two-year time period, leading to premature termination of the study. In contrast, we easily recruited motivated lay volunteers. We found no change in HbA1c from the initial to the 6-mo visit in either group, yet our small sample size limited systematic assessment of this outcome. Participants repeatedly missed clinic appointments, failed to conduct self-glucose-monitoring and rarely brought their glucometers to clinic visits. Total quality of life scores (72.6 ± 6.06) at screening were similar to previously reported scores in adolescents with type 2 diabetes (75.7 ± 15.0) and lower than scores reported in normal-weight (81.2 ± 0.9), overweight (83.5 ± 1.8), and obese youths without diabetes (78.5 ± 1.8) or in adolescents with type 1 diabetes (80.5 ± 13.1). Among adolescents who returned for their 6-mo visit, there were no differences in total quality of life scores (70.2 ± 9.18) between screening and follow-up.
CONCLUSION: Our approach, effective in adults with type 2 diabetes, was unsuccessful among adolescents and emphasizes the need for innovative strategies for diabetes treatment in adolescent patients
Shape and structure of N=Z 64Ge; Electromagnetic transition rates from the application of the Recoil Distance Method to knock-out reaction
Transition rate measurements are reported for the first and the second 2+
states in N=Z 64Ge. The experimental results are in excellent agreement with
large-scale Shell Model calculations applying the recently developed GXPF1A
interactions. Theoretical analysis suggests that 64Ge is a collective
gamma-soft anharmonic vibrator. The measurement was done using the Recoil
Distance Method (RDM) and a unique combination of state-of-the-art instruments
at the National Superconducting Cyclotron Laboratory (NSCL). States of interest
were populated via an intermediate-energy single-neutron knock-out reaction.
RDM studies of knock-out and fragmentation reaction products hold the promise
of reaching far from stability and providing lifetime information for excited
states in a wide range of nuclei
Observation of isotonic symmetry for enhanced quadrupole collectivity in neutron-rich 62,64,66Fe isotopes at N=40
The transition rates for the 2_{1}^{+} states in 62,64,66Fe were studied
using the Recoil Distance Doppler-Shift technique applied to projectile Coulomb
excitation reactions. The deduced E2 strengths illustrate the enhanced
collectivity of the neutron-rich Fe isotopes up to N=40. The results are
interpreted by the generalized concept of valence proton symmetry which
describes the evolution of nuclear structure around N=40 as governed by the
number of valence protons with respect to Z~30. The deformation suggested by
the experimental data is reproduced by state-of-the-art shell calculations with
a new effective interaction developed for the fpgd valence space.Comment: 4 pages, 2 figure
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