278 research outputs found

    Quantum steering for continuous variable in de Sitter space

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    We study the distribution of quantum steerability for continuous variables between two causally disconnected open charts in de Sitter space. It is shown that quantum steerability suffers from "sudden death" in de Sitter space, which is quite different from the behaviors of entanglement and discord because the latter always survives and the former vanishes only in the limit of infinite curvature. In addition, we find that the attainment of maximal steerability asymmetry indicates a transition between unidirectional steerable and bidirectional steerable. Unlike in the flat space, the asymmetry of quantum steerability can be completely destroyed in the limit of infinite curvature for the conformal and massless scalar fields in de Sitter space.Comment: 22 pages, 7 figure

    Revolutionising health care: Exploring the latest advances in medical sciences

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    Recent years have seen a revolution in the domain of medical science, with ground-breaking discoveries changing health care as we once knew it [1]. These advances have considerably improved disease diagnosis, treatment, and management, improving patient outcomes and quality of life [2–5]. . .

    Black-box estimation of expanding parameter for de Sitter universe

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    We study the black-box parameter estimation of expanding parameters and the dynamics of Gaussian interferometric power for the de Sitter space. We find that the state between separated open charts can be employed as probe state for the black-box quantum metrology. This is nontrivial because the open charts are causally disconnected and classical information can not be exchanged between them according to the general relativity. It is shown that the mass of the scalar field remarkably affects the accuracy of the black-box parameter estimation in the de Sitter space, which is quite different from the flat space case where the mass parameter does not influence the precision of estimation. Quantum discord is found to be a key resource for the estimation of the expanding parameter when there is no entanglement between the initially uncorrelated open charts.It is demonstrated that the role of the probe state between different open charts is quite distinct because curvature effect of the de sitter space damages quantum resources for the initially correlated probe states, while it generates quantum resources for the initially uncorrelated probe states.Comment: 16 pages, 8 figure

    Reap success from persistence

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    The road to success is long and arduous. Almost all Nobel prize laureates experienced tremendous efforts and countless failures before they made their scientific breakthroughs. Hypothesis-driven, independent and critical thinking, passion, repeated experiments and repetitive failures and running in circles on the entire scientific process finally approved their hypotheses

    Quantum properties of fermionic fields in multi-event horizon spacetime

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    We investigate the properties of quantum entanglement and mutual information in the multi-event horizon Schwarzschild-de Sitter (SdS) spacetime for massless Dirac fields. We obtain the expression for the evolutions of the quantum state near the black hole event horizon (BEH) and cosmological event horizon (CEH) in the SdS spacetime. Under the Nariai limit, the physically accessible entanglement and mutual information are maximized, and the physically inaccessible correlations are zero. With the increase in temperature of either horizon, the physically accessible correlations experience degradation. Notably, the initial state remains entangled and can be utilized in entanglement-based quantum information processing tasks, which differs form the scalar field case. Furthermore, the degradation of physically accessible correlations is more pronounced for small-mass black holes. In contrast, the physically inaccessible correlations separated by the CEH monotonically increase with the radiation temperature, and such correlations are not decisively influenced by the effect of particle creation at the BEH. Moreover, a similar phenomenon is observed for the inaccessible correlations separated by the BEH. This result differs from the single event spacetime, in which the physically inaccessible entanglement is a monotonic function of the Hawking temperature.Comment: 14 pages, 7 figure

    Gravity enhanced quantum spatial target detection

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    Quantum illumination can utilize entangled light to detect the low-reflectivity target that is hidden in a bright thermal background. We apply this technique to the detection of an object under the curved spacetime of the Earth, and are especially interested in how the curvature of spacetime influences the spatial quantum illumination. We find that in the near-Earth curved spacetime, the spatial quantum illumination with entangled state transmitter outperforms the one with coherent state transmitter. Furthermore, whether the quantum illumination system or the coherent state system is employed, the detection error-probability and the transmitted modes in the curved spacetime case are always lower than those in the flat spacetime case. That is to say, the Earth's gravity makes the spatial target detection more efficient. This is because the effects of gravity on the illumination signal beam can cancel each other out, while the thermal noise in the return signal is reduced because of the gravitational effect.Comment: 16 pages, 5 figure

    Rosavin exerts an antitumor role and inactivates the MAPK/ERK pathway in small-cell lung carcinoma in vitro

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    This study attempts to explore the function and mechanism of action of rosavin in small-cell lung cancer (SCLC) in vitro. The viability and clone formation of SCLC cells were assessed using cell counting kit-8 and colony formation assays, respectively. Apoptosis and cell cycle were detected using flow cytometry and cell cycle analysis, respectively. Wound healing and transwell assays were performed to evaluate the migration and invasion of SCLC cells. Besides, protein levels of p-ERK, ERK, p-MEK and MEK were determined using western blot analysis. Rosavin repressed the viability and clone formation of SCLC cells, and promoted apoptosis and G0/G1 arrest of SCLC cells. At the same time, rosavin suppressed migration and invasion of SCLC cells. Moreover, protein levels of p-ERK/ERK and p-MEK/MEK were decreased after rosavin addition in SCLC cells. Rosavin impaired malignant behaviors of SCLC cells, which may be associated with inhibition of the MAPK/ERK pathway in vitro

    Experimental investigations on drag-reduction characteristics of bionic surface with water-trapping microstructures of fish scales

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    Biological surfaces with unique wettability in nature have provided an enormous innovation for scientists and engineers. More specifically, materials possessing various wetting properties have drawn considerable attention owing to their promising application prospects. Recently, great efforts have been concentrated on the researches on wetting-induced drag-reduction materials inspired by biology because of their ability to save energy. In this work, the drag-reduction characteristics of the bionic surface with delicate water-trapping microstructures of fish Ctenopharyngodon idellus scales were explored by experimental method. Firstly, the resistance of smooth surface and bionic surface experimental sample at different speeds was carefully tested through the testing system for operation resistance. Then, the contact angle (CA) of fish scale surface was measured by means of the contact angle measuring instrument. It was discovered that the bionic surface created a rewarding drag-reduction effect at a low speed, and the drag-reduction rate significantly displayed a downward trend with the increase in flow speed. Thus, when the rate was 0.66 m/s, the drag-reduction effect was at the optimum level, and the maximum drag reduction rate was 2.805%, which was in concordance with the simulated one. Furthermore, a contact angle (CA) of 11.5° appeared on the fish scale surface, exhibiting fine hydrophilic property. It further manifested the spreading-wetting phenomenon and the higher surface energy for the area of apical of fish scales, which played an important role in drag-reduction performance. This work will have a great potential in the engineering and transportation field

    The integration path and promotion of new business majors and ideological and political education in the era of great changes

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    The world is experiencing unprecedented changes, and from historical experience, the era of great changes often means opportunities and challenges. To seize opportunities and better meet challenges, talent is indispensable. Ideological and political education is a very important component of achieving the goal of "cultivating morality and talents" in universities, and it is also a very important way to improve the quality of talent cultivation. Therefore, the article studies the necessity and integration path of ideological and political education in new business majors in the era of great changes, and proposes promotion strategies for the integration of new business majors and ideological and political education, in order to help them better achieve integration in the era of great changes
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