2,000 research outputs found
Field-dependent quantum nucleation of antiferromagnetic bubbles
The phenomenon of quantum nucleation is studied in a nanometer-scale
antiferromagnet with biaxial symmetry in the presence of a magnetic field at an
arbitrary angle. Within the instanton approach, we calculate the dependence of
the rate of quantum nucleation and the crossover temperature on the orientation
and strength of the field for bulk solids and two-dimensional films of
antiferromagnets, respectively. Our results show that the rate of quantum
nucleation and the crossover temperature from thermal-to-quantum transitions
depend on the orientation and strength of the field distinctly, which can be
tested with the use of existing experimental techniques.Comment: 21 pages, 5 figures, Final version and accepted by Eur. Phys. J
A Model of Two-Way Selection System for Human Behavior
We propose a model of two-way selection system. It appears in the processes
like choosing a mate between men and women, making contracts between job
hunters and recruiters, and trading between buyers and sellers. In this paper,
we propose a model of two-way selection system, and present its analytic
solution for the expectation of successful matching total and the regular
pattern that the matching rate trends toward an inverse proportion to either
the ratio between the two sides or the ratio of the state total to the smaller
people number. The proposed model is verified by empirical data of the
matchmaking fairs. Results indicate that the model well predicts this typical
real-world two- way selection behavior to the bounded error extent, thus it is
helpful for understanding the dynamics mechanism of the real-world two-way
selection system.Comment: 8 pages, 4 figure
Prospects of violation in decay with polarized electron beam at STCF
Based on Monte
Carlo (MC) events produced from a longitudinally-polarized electron beam, the
sensitivity of violation of decay is studied with fast
simulation software. In addition, the decay can also be used as a process to optimize the detector
response using the interface provided by the fast simulation software. In the
future, STCF is expected to obtain 3.4 trillion events, and the
statistical sensitivity of violation of decay via process is expected to reach ~ when the electron beam polarization is 80\%
Ginsenoside Rb1 Reduces Nitric Oxide Production via Inhibition of Nuclear Factor-κB Activation in Interleukin-1β- Stimulated SW1353 Chondrosarcoma Cells
Purpose: To investigate the effect and the potential mechanisms of ginsenoside Rb1 on nitric oxide (NO) production in chondrocytes.Methods: SW1353 chondrosarcoma cells were stimulated with interleukin-1β (IL-1β) in the presence of 20, 40, 80 μM ginsenoside Rb1. NO concentration was assessed by the Griess reaction. Expression of inducible nitric oxide synthase (iNOS), content of inhibitor of NF-κB (IκB)α and nuclear level of nuclear factor (NF)-κB p65 were determined by Western blot. DNA binding activity of NF-κB was evaluated with Trans AM™ kit for NF-κB p65.Results: Ginsenoside Rb1 (40 and 80 μM) significantly decreased NO level by 24 (p < 0.05) and 46 % (p < 0.01), as well as iNOS protein expression by 40 and 55 % (p < 0.01), respectively, in IL-1β- stimulated SW1353 cells. Ginsenoside Rb1 (40 and 80 μM) also markedly elevated IκBα protein content by 200 and 260 % (p < 0.01), reduced the nuclear level of p65 protein by 30 and 40 % (p < 0.01), as well as decreased the DNA binding activity of NF-κB by 40 and 50 % (both p < 0.01), respectively, in IL- 1β-stimulated SW1353 cells.Conclusion: These results suggest that ginsenoside Rb1 inhibits IL-1β-induced NO production through downregulation of NF-κB-dependent iNOS expression in chondrocytes, and also underlines the potential mechanisms of ginseng activity in OA treatment of TCM. Keywords: Ginsenoside Rb1, Nitric oxide, Nuclear factor-κB, Chondrocytes, Osteoarthriti
Pollutant diffusion in multiple-face tunnel construction: theoretical analysis and numerical validation
As the length of the tunnel continues to increase, it will be common for a single fan to undertake the ventilation of two or more tunnel faces. However, the construction of multiple faces in a single tunnel will lead to a complex construction environment in the tunnel, the mutual interference of ventilation, and difficulty in discharging pollutants. Based on the simultaneous construction of multiple tunnel faces in a single tunnel, this study analyzed the transport law of pollutants. The diffusion laws of carbon monoxide and dust in multiple-face tunnels under different working conditions were obtained by numerical simulation. It was found that when both sides of the tunnel are ventilated at the same time, the airflow in the tunnel is spiral, the vortex zone will appear near both sides of the face, and the vortex and unstable airflow will appear at the intersection with the inclined shaft. The airflow in the non-equal-length tunnel at both sides is more disordered than that in the equal-length tunnel, and there will be a wider range of eddy currents at the intersection. The change of dust diffusion in the non-equal-length tunnel at both sides is not obvious, and the length of the multiple-face tunnel has little effect on dust settlement and diffusion. The research results are of great significance for improving the construction environment of tunnel faces and improving the working conditions of personnel
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