224 research outputs found
Interaction-induced anomalous transport behavior in one dimensional optical lattice
The non-equilibrium dynamics of spin impurity atoms in a strongly interacting
one-dimensional (1D) Bose gas under the gravity field is studied. We show that
due to the non-equilibrium preparation of the initial state as well as the
interaction between the impurity atoms and other bosons, a counterintuitive
phenomenon may emerge: the impurity atoms could propagate upwards automatically
in the gravity field . The effects of the strength of interaction, the gradient
of the gravity field, as well as the different configurations of the initial
state are investigated by studying the time-dependent evolution of the 1D
strongly interacting bosonic system using time-evolving block decimation (TEBD)
method. A profound connection between this counterintuitive phenomenon and the
repulsive bound pair is also revealed.Comment: 4.1 page
Exploring the Dark Energy Equation of State with JWST
Observations from the James Webb Space Telescope (JWST) have unveiled several
galaxies with stellar mass at . These remarkable findings indicate an unexpectedly high stellar
mass density, which contradicts the prediction of the model.
We adopt the Chevallier--Polarski--Linder (CPL) parameterization, one of the
dynamic dark energy models, to probe the role of dark energy on shaping the
galaxy formation. By considering varying star formation efficiencies within
this framework, our analysis demonstrates that an increased proportion of dark
energy in the universe corresponds to the formation of more massive galaxies at
higher redshifts, given a fixed perturbation amplitude observed today.
Furthermore, through elaborately selecting CPL parameters, we successfully
explain the JWST observations with star formation efficiencies
at a confidence level of . These intriguing results
indicate the promising prospect of revealing the nature of dark energy by
analyzing the high-redshift massive galaxies.Comment: 7 pages, 3 figure
Multi-Objective Robust Design of New Rotate Barrel Based on Satisfaction Function
R E T R A C T E D
A R T I C L E
In this paper, a multi-objective robust design method based on satisfaction function was proposed by combining satisfaction function with Taguchi robust to solve the multi-objective optimization problem, which was easily interfered by noise factor. This method converted the signal-to-noise ratio of product quality characteristics into the expected smaller-the-better of Taguchi robust design, and realized the multi-objective robust design by weighted geometric mean, so as to solve the multi-objective optimization problem easily affected by noise factors. Under the premise of without changing rotate barrel of basic size by LS-DYNA FE model of rotary guardrail, the proposed method was carried out on the rotate barrel of multi-objective robust design, in order to solve the new rotary guardrail section parameter uncertain multi-objective optimization design. The results showed that the robust design of the new rotate barrel could resist the interference of the noise, the structure was more robust, and it conformed to the relevant laws and regulations by which was realized the purpose of lightweight of the new rotary guardrail. The research results had certain theoretical and engineering significance in improving the robustness of the new rotary guardrail
A Novel Microwave Tunable Band-Pass Filter Integrated Power Divider Based on Liquid Crystal
This paper proposes a novel microwave continuous adjustable band-pass filter integrated power divider based on nematic liquid crystals (LCs). The proposed power divider uses liquid crystal (LC) as the dielectric material. It can realize phase shift by changing the dielectric anisotropy, when biasing the high anisotropy nematic liquid crystal. It is mainly used in microwave frequencies. It has a large number of advantages compared to conventional filter integrated power divider, such as low loss, multifunction integration, continuous adjustable, miniaturization, low processing costs, low operating voltage, high phase shift, and convenient manufacture. Therefore, it has shown great potential for application
A Study of Wolf Pack Algorithm for Test Suite Reduction
Modern smart meter programs are iterating at an ever-increasing rate, placing higher demands on the software testing of smart meters. How to reduce the cost of software testing has become a focus of current research. The reduction of test overhead is the most intuitive way to reduce the cost of software testing. Test suite reduction is one of the necessary means to reduce test overhead. This paper proposes a smart meter test suite reduction technique based on Wolf Pack Algorithm. First, the algorithm uses the binary optimization set coverage problem to represent the test suite reduction of the smart meter program; then, the Wolf Pack Algorithm is improved by converting the positions of individual wolves into a 0/1 matrix; finally, the optimal test case subset is obtained by iteration. By simulating different smart meter programs and different size test suites, the experimental result shows that the Wolf Pack Algorithm achieves better results compared to similar algorithms in terms of the percentage of obtaining both the optimal solution and the optimal subset of test overhead
Constraints on ultracompact minihalos from extragalactic {\gamma}-ray background
It has been proposed that ultracompact minihalos (UCMHs) might be formed in
earlier epoch. If dark matter consists of Weakly Interacting Massive Particles
(WIMPs), UCMHs can be treated as the {\gamma}-ray sources due to dark matter
annihilation within them. In this paper, we investigate the contributions of
UCMHs formed during three phase transi- tions (i.e., electroweak symmetry
breaking, QCD confinement and e+ e- annihilation) to the extragalactic
{\gamma}-ray background. Moreover, we use the Fermi-LAT observation data of the
extragalactic {\gamma}-ray background to get the constraints on the current
abundance of UCMHs produced during these phase transitions. We also compare
these results with those obtained from Cosmic Microwave Background (CMB)
observations and find that the constraints from the Fermi-LAT are more
stringent than those from CMBComment: 13 pages, 4 figures, 1 tabl
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