28 research outputs found
Detecting circular Unruh effect with quantum entanglement
We show that the asymptotic state of a quantum system composed of two atoms
in circular motion in vacuum can be entangled when the angular velocity and the
radius of the orbit are appropriate. The asymptotic entanglement as a result of
centripetal acceleration is initial-state independent and can be viewed as a
manifestation of the circular version of the Unruh effect. Based on this
phenomenon, we propose an optomechanical setup to detect the circular Unruh
effect with the state-of-the-art technologies.Comment: 5 pages, 2 figure
Rotating BTZ-like black hole and central charges in Einstein-bumblebee gravity
We obtain an exact rotating BTZ-like black hole solution by solving the
corresponding gravitational field equations in Einstein-bumblebee gravity
theory. Result is presented for the purely radial Lorentz symmetry violating
and can only exist with a linear functional potential of the bumblebee field.
This black hole has two horizons and an ergosphere which are dependent on the
bumblebee coupling constant . We study the AdS/CFT correspondence of this
black hole, find that the entropy product of its inner and outer horizons is
universal. So the central charges of the dual CFT on the boundary can be
obtained via the thermodynamic method, and they can reappear black hole mass
and angular momentum in the bulk.Comment: 12 pages, no figure. arXiv admin note: text overlap with
arXiv:2201.0668
Air Duct Optimization Design Based on Local Turbulence Loss Analysis and IMOCS Algorithm
Considering the complex flow state of the duct flow field in the exhaust system, the structural parameters can significantly impact the internal flow field and noise. This paper takes the noise generated by the duct system under operating conditions as the research object, studies the mechanism of duct noise generation through theoretical analysis, numerical simulation and experimental test, and proposes an optimization design method, that is, to improve the duct structure by adding duct guide vanes. In order to maximize the optimization effect of the guide vane, a multiobjective optimization design of its profile is required, including the parametric expression of the guide vane profile, establishing the design variables and optimization objectives, and establishing the Kriging approximation model. The IMOCS algorithm is used to accurately and efficiently calculate the Pareto front solution to obtain the optimal profile of the duct guide vane and finally improve the noise-reduction performance of the duct system. This paper applies this design method to an integrated stove head duct to verify its accuracy, and prototype tests are conducted according to the optimization results. The test results show that the optimized integrated cooker has improved the outlet flow rate of the whole machine by 1.2 m3/min and reduced the noise by 2.3 dB
2011): The role of EDTA on Cadmium phytoextraction in a Cadmiumhyperaccumulator Rorippa globosa
Enhanced phytoextraction technologies have been proposed as an effective approach to the decontamination of heavy metals in soils. In this study, the application of ethylene diamine tetraacetic acid (0.5 and 1.0 g/kg EDTA) at preflowering stage depressed Rorippa globosa growth and Cd uptake, the dry biomass, Cd concentration and total metal accumulation (TMC) of shoots at the concentration of 1.0 g/kg EDTA resulted in 39.6, 3.1 and 41.0% reduction, respectively, relative to the control. In contrast, when EDTA was added at flowering and mature stages, it facilitated plant production and Cd absorption. Especially for 1.0 g/kg EDTA applied at mature stage, the maximum of shoot dry biomass, Cd concentration, TMC and remediation ratio (RR) were obtained, which were 4.7 g/pot, 210.3 mg/kg, 982.4 µg/pot and 1.6, respectively. Therefore, the moderate concentration of EDTA (1.0 g/kg) applied at optimal growing stage (mature stage) of R. globosa was more effective in increasing phytoextraction of Cd from contaminated soils
Phytoremediation of heavy metal contaminated saline soils using halophytes: current progress and future perspectives
Soil salinity is a destructive environmental stressor that greatly reduces plant growth and productivity. In recent years, large tracts of farmland in arid and semiarid regions have been simultaneously affected by salinity and heavy metal pollution, arousing widespread environmental concern. Phytoremediation, defined as the use of plants to remove pollutants from the environment and/or to render them harmless, is a low cost, environmentally friendly, and effective method for the decontamination of soils polluted by heavy metals. Halophytes, which can survive and reproduce in high salt environments, are potentially ideal candidates for phytoremediation of heavy metal-contaminated saline soils. In this review, we discuss the current progress on the use of halophytes, their tolerance mechanisms to salt and heavy metal toxicity, and their potential for phytoremediation in heavy metal-contaminated saline soils. The relative mechanisms are discussed and the future perspectives are proposed.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
The Effect of Clamping Force on the Wear Behavior of a Steam Generator Tube
Anti-vibration bars (AVBs) are essential components of a steam generator (SG) and are used to prevent steam generator tubes (SGTs) from vibrating intensely because of flow-induced vibration. However, the contact force generated at contact surfaces between AVBs and tubes can change the natural frequency and wear behavior of the tube. Contact force is represented by clamping force in this study. Considering the effect of the clamping force on the natural frequency and sliding distance of SGT, dynamic wear behavior under different clamping forces was analyzed based on the finite element method, and the natural frequency of the tube was measured in the present work. Moreover, the wear experiment was conducted at room temperature to verify the conclusions of dynamic behavior analysis. The increase in clamping force reduces the sliding distance of SGT, and wear depth affected by both clamping force and sliding distance also decreases
The Effect of Clamping Force on the Wear Behavior of a Steam Generator Tube
Anti-vibration bars (AVBs) are essential components of a steam generator (SG) and are used to prevent steam generator tubes (SGTs) from vibrating intensely because of flow-induced vibration. However, the contact force generated at contact surfaces between AVBs and tubes can change the natural frequency and wear behavior of the tube. Contact force is represented by clamping force in this study. Considering the effect of the clamping force on the natural frequency and sliding distance of SGT, dynamic wear behavior under different clamping forces was analyzed based on the finite element method, and the natural frequency of the tube was measured in the present work. Moreover, the wear experiment was conducted at room temperature to verify the conclusions of dynamic behavior analysis. The increase in clamping force reduces the sliding distance of SGT, and wear depth affected by both clamping force and sliding distance also decreases