8,325 research outputs found
Non-Fermi Liquid Behavior of the - Model in the Strange Metal Phase: Gauge Theory with Local Constraints
We use the Becchi-Rouet-Stora-Tyutin (BRST) method to quantize the -
model in the gauge slave boson representation. While the temporal
component of the gauge field plays a role of a Lagrange multiplier to enforce
the no double occupancy constraint, the spatial components do that to enforce
the zero counterflow constraint of the spinon and holon currents. The BRST
quantization guarantees the gauge invariance of the theory and removes the
redundant gauge degrees of freedom by proper gauge fixing conditions while the
no double occupancy and zero counterflow constraints are exactly retained.
Furthermore, Fradkin-Vilkovisky gauge fixing conditions endow the gauge field
with dynamics. This turns the strongly correlated electron model into a weakly
coupled slave boson model, most of whose physical observables can be calculated
by the conventional quantum many-body perturbation theory. We focus on the
properties of the strange metal phase in the - model. The electron
momentum distribution and the spectral function are calculated, and their
non-Fermi liquid behavior agrees with the angle resolved photoemission
spectroscopy measurements for the cuprate materials. We also study the
responses of the strange metal state to the external electromagnetic fields.
The non-Fermi liquid anomalies observed in cuprates are captured by our
calculations. Especially, we find that the Hall resistivity decreases as
temperature raises and the sign of the Hall resistivity varies from negative to
positive when the dopant concentration varies from the optimal doping one to
underdoping one when the temperature .Comment: v1: 20 pages; v2: 21 pages, 8 figures. A few changes and new
references added. All comments are welcom
The Effects of Salt on Rheological Properties of Asphalt after Long-Term Aging
Limited studies in recent years have shown that asphalt pavement subject to seawater in coastal regions or deicing salt in cold regions may be seriously damaged after being soaked in saline water for a long time. However, there is limited research into the influence of salt on rheological properties of asphalt after long-term aging. In this study, rheological properties of unmodified and polymer-modified asphalt after long-term aging were tested after being soaked in different concentrations of salt (0.3%~5%) for different durations (1 day~30 days). Orthogonal array based on the Taguchi method was used for experimental design. The frequency sweep tests were performed on the specimens of aged asphalt after being soaked for complex modulus and phase angle master curves and ultimate fatigue temperature. BBR tests were performed for stiffness. The test results indicate that saline water appears to reduce low temperature properties and fatigue resistance properties and improved high temperature properties of aged asphalt, and it also affects the sensitivity of complex modulus and phase angles at low frequencies
Performance Analysis of Non-ideal Wireless PBFT Networks with mmWave and Terahertz Signals
Due to advantages in security and privacy, blockchain is considered a key
enabling technology to support 6G communications. Practical Byzantine Fault
Tolerance (PBFT) is seen as the most applicable consensus mechanism in
blockchain-enabled wireless networks. However, previous studies on PBFT do not
consider the channel performance of the physical layer, such as path loss and
channel fading, resulting in research results that are far from real networks.
Additionally, 6G communications will widely deploy high frequency signals such
as millimeter wave (mmWave) and terahertz (THz), while the performance of PBFT
is still unknown when these signals are transmitted in wireless PBFT networks.
Therefore, it is urgent to study the performance of non-ideal wireless PBFT
networks with mmWave and THz siganls, so as to better make PBFT play a role in
6G era. In this paper, we study and compare the performance of mmWave and THz
signals in non-ideal wireless PBFT networks, considering Rayleigh Fading (RF)
and close-in Free Space (FS) reference distance path loss. Performance is
evaluated by consensus success rate and delay. Meanwhile, we find and derive
that there is a maximum distance between two nodes that can make PBFT consensus
inevitably successful, and it is named active distance of PBFT in this paper.
The research results not only analyze the performance of non-ideal wireless
PBFT networks, but also provide an important reference for the future
transmission of mmWave and THz signals in PBFT networks.Comment: IEEE International Conference on Metaverse Computing, Networking and
Applications (MetaCom) 202
Effect of PPARγ agonist (rosiglitazone) on the secretion of Th2 cytokine in asthma mice
AbstractObjectiveTo explore the effect of PPARγ agonist (rosiglitazone) on the secretion of Th2 cytokines and the proportion of immune cell subsets in asthma mice.MethodsOvalbumin (OVA)-sensitized mice were used to build asthma models. Those mice were divided into the normal control group, model group and rosiglitazone group. Differences of the changes in lung histopathology of mice in the three groups were observed through hematoxylin and eosin (HE) strain, and the numbers of the total cells, eosinophils and neutrophils in BALF of mice in the three groups were compared. ELISA and real-time PCR were employed to detect the protein levels of interleukin (IL)-5, IL-13, IL-4 and IL-10 and mRNA level, respectively. Flow cytometry number was implied to analyze the proportion of immune cell subsets in peripheral blood of mice.ResultsCompared with the mice in the control group, and mice of the model group, the infiltration of inflammatory cells in BALF increased, bronchial smooth muscle became thickened, a large amount of collagen deposited, the secretion of Th2 cytokine increased significantly, the ratio of regulatory T cells (Treg) decreased, the ratio of T17 cells rose distinctly; while in mice of the rosiglitazone group, the changes of their lung histopathology were improved obviously, the number of infiltration of inflammatory cells declined, the thickened smooth muscle relieved, the deposition of collagen decreased, the secretion of Th2 cytokine was inhibited, the ratio of Treg went up, and the increased of the ratio of T17 cells was inhibited but still not return to normal level.ConclusionsRosiglitazone can regulate the proportion of Treg and Th17 cells and inhibit the secretion of Th2 cytokines, which inhibit the airway inflammatory response for asthma mice effectively
TripleRE: Knowledge Graph Embeddings via Tripled Relation Vectors
Translation-based knowledge graph embedding has been one of the most
important branches for knowledge representation learning since TransE came out.
Although many translation-based approaches have achieved some progress in
recent years, the performance was still unsatisfactory. This paper proposes a
novel knowledge graph embedding method named TripleRE with two versions. The
first version of TripleRE creatively divide the relationship vector into three
parts. The second version takes advantage of the concept of residual and
achieves better performance. In addition, attempts on using NodePiece to encode
entities achieved promising results in reducing the parametric size, and solved
the problems of scalability. Experiments show that our approach achieved
state-of-the-art performance on the large-scale knowledge graph dataset, and
competitive performance on other datasets
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