3,404 research outputs found
BCS thermal vacuum of fermionic superfluids and its perturbation theory
The thermal field theory is applied to fermionic superfluids by doubling the
degrees of freedom of the BCS theory. We construct the two-mode states and the
corresponding Bogoliubov transformation to obtain the BCS thermal vacuum. The
expectation values with respect to the BCS thermal vacuum produce the
statistical average of the thermodynamic quantities. The BCS thermal vacuum
allows a quantum-mechanical perturbation theory with the BCS theory serving as
the unperturbed state. We evaluate the leading-order corrections to the order
parameter and other physical quantities from the perturbation theory. A direct
evaluation of the pairing correlation as a function of temperature shows the
pseudogap phenomenon results from the perturbation theory. The BCS thermal
vacuum is shown to be a generalized coherent and squeezed state. The
correspondence between the thermal vacuum and purification of the density
matrix allows a unitary transformation, and we found the geometric phase in the
parameter space associated with the transformation.Comment: 14 pages, 2 figure
DNA oxidation after exercise: a systematic review and meta-analysis
Purpose: 8-Hydroxy-2′-deoxyguanosine (8-OHdG) is a byproduct of DNA oxidation resulting from free radical attacks. Paradoxically, treatment with 8-OHdG accelerates tissue healing. The aim of this study is to quantify the 8-OHdG response after a single session of exercise in both trained and untrained adults.Methods: A systematic review and meta-analysis of exercise intervention studies measuring changes in blood 8-OHdG following resistance exercise and aerobic exercise were conducted. The literature search included Web of Science, PubMed, BASE, and Scopus, with publications up to February 2023 included. Subgroup analysis of training status was also conducted.Results: Sixteen studies involving 431 participants met the eligibility criteria. Resistance exercise showed a medium effect on increasing circulating 8-OHdG levels (SMD = 0.66, p < 0.001), which was similar for both trained and untrained participants. However, studies on aerobic exercise presented mixed results. For trained participants, a small effect of aerobic exercise on increasing circulating 8-OHdG levels was observed (SMD = 0.42; p < 0.001). In contrast, for untrained participants, a large effect of decreasing circulating 8-OHdG levels was observed, mostly after long-duration aerobic exercise (SMD = −1.16; p < 0.05). Similar to resistance exercise, high-intensity aerobic exercise (5–45 min, ≥75% VO2max) significantly increased circulating 8-OHdG levels, primarily in trained participants.Conclusion: Pooled results from the studies confirm an increase in circulating 8-OHdG levels after resistance exercise. However, further studies are needed to fully confirm the circulating 8-OHdG response to aerobic exercise. Increases in 8-OHdG after high-intensity aerobic exercise are observed only in trained individuals, implicating its role in training adaptation.Systematic Review Registration: [https://Systematicreview.gov/], identifier [CRD42022324180
Using Hybrid Angle/Distance Information for Distributed Topology Control in Vehicular Sensor Networks
In a vehicular sensor network (VSN), the key design issue is how to organize vehicles effectively, such that the local network topology can be stabilized quickly. In this work, each vehicle with on-board sensors can be considered as a local controller associated with a group of communication members. In order to balance the load among the nodes and govern the local topology change, a group formation scheme using localized criteria is implemented. The proposed distributed topology control method focuses on reducing the rate of group member change and avoiding the unnecessary information exchange. Two major phases are sequentially applied to choose the group members of each vehicle using hybrid angle/distance information. The operation of Phase I is based on the concept of the cone-based method, which can select the desired vehicles quickly. Afterwards, the proposed time-slot method is further applied to stabilize the network topology. Given the network structure in Phase I, a routing scheme is presented in Phase II. The network behaviors are explored through simulation and analysis in a variety of scenarios. The results show that the proposed mechanism is a scalable and effective control framework for VSNs
Research on the Motivation and Attitude of College students' Physical Education in Taiwan
College students' physical education plays an important role in physical activity and cultivates the concept of independent health management. At present, what kind of learning attitude do Taiwan college students face in physical education? What motivation does the student influence the attitude of the physical education? What is the relevance? All of the above are the purpose of this study. The research method adopts the questionnaire survey method, and the survey data adopts descriptive statistical analysis, independent sample t test, single factor variance analysis, LSD post hoc comparison method, and typical correlation analysis. Research results: 1. The different background variables of Taiwanese college students are that the main motivation factor of physical education is to obtain good health fitness for "physical health". 2. Taiwanese college students have different background variables. They all think that the "cognitive learning" of physical education is the main factor of attitude, that is, the knowledge about health care and sports skills. 3. There is a positive correlation between learning motivation and learning attitude (ρ=.90). Learning motivation is one of the important factors affecting learning attitude. Research conclusions: 1. The factors of Taiwanese male and female college students' motivation for learning in physical education are mainly based on "physical health". 2. Freshmen have higher motivations and learning attitudes in physical education than second-grade to fourth-grade. 3. Taiwan female college students average 1 or 2 times per week, male college students have the most athletes 2 to 3 times per week, more than 90% of college students like sports. 4. There is a positive correlation between learning motivation and learning attitude, indicating that the stronger the attribute of learning motivation "physical health", the higher the student's learning attitude. 5. Satisfying students' motivation for learning helps students to learn positively. 6. Another important task of the college physical education class is to prepare students for future lifelong sports
Delving into Motion-Aware Matching for Monocular 3D Object Tracking
Recent advances of monocular 3D object detection facilitate the 3D
multi-object tracking task based on low-cost camera sensors. In this paper, we
find that the motion cue of objects along different time frames is critical in
3D multi-object tracking, which is less explored in existing monocular-based
approaches. In this paper, we propose a motion-aware framework for monocular 3D
MOT. To this end, we propose MoMA-M3T, a framework that mainly consists of
three motion-aware components. First, we represent the possible movement of an
object related to all object tracklets in the feature space as its motion
features. Then, we further model the historical object tracklet along the time
frame in a spatial-temporal perspective via a motion transformer. Finally, we
propose a motion-aware matching module to associate historical object tracklets
and current observations as final tracking results. We conduct extensive
experiments on the nuScenes and KITTI datasets to demonstrate that our MoMA-M3T
achieves competitive performance against state-of-the-art methods. Moreover,
the proposed tracker is flexible and can be easily plugged into existing
image-based 3D object detectors without re-training. Code and models are
available at https://github.com/kuanchihhuang/MoMA-M3T.Comment: Accepted by ICCV 2023. Code is available at
https://github.com/kuanchihhuang/MoMA-M3
Nanoparticle-induced negative differential resistance and memory effect in polymer bistable light-emitting device
Recently, electrical bistability was demonstrated in polymer thin films incorporated with metal nanoparticles [J. Ouyang, C. W. Chu, C. R. Szmanda, L. P. Ma, and Y. Yang, Nat. Mater. 3, 918 (2004)]. In this letter, we show the evidence that electrons are the dominant charge carriers in these bistable devices. Direct integration of bistable polymer layer with a light-emitting polymer layer shows a unique light-emitting property modulated by the electrical bistability. A unique negative differential resistance induced by the charged gold nanoparticles is observed due to the charge trapping effect from the nanoparticles when interfaced with the light-emitting layer
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