742 research outputs found

    Review on recent liquefied natural gas cold energy utilization in power generation cycles

    Get PDF
    Liquefied natural gas (LNG) needs to be gasified before supplied to the users, and considerable amount of cold energy, about 830 kJ/kg, will be released during this process. Recovery of LNG cold energy bears significance of energy-saving and environmental protection. Among the many ways of using LNG cold energy, power generation is the most effective and suitable one for large-scale applications. Many novel power generation cycles have been designed for utilizing LNG cold energy so far. This paper reviews the recent researches on LNG cold energy utilization in power generation, and discusses 15 novel power generation cycles utilizing LNG cold energy.Cited as: Yu, G., Jia, S., Dai, B. Review on recent liquefied natural gas cold energy utilization in power generation cycles. Advances in Geo-Energy Research, 2018, 2(1): 86-102, doi: 10.26804/ager.2018.01.0

    Quantum interface between frequency-uncorrelated down-converted entanglement and atomic-ensemble quantum memory

    Full text link
    Photonic entanglement source and quantum memory are two basic building blocks of linear-optical quantum computation and long-distance quantum communication. In the past decades, intensive researches have been carried out, and remarkable progress, particularly based on the spontaneous parametric down-converted (SPDC) entanglement source and atomic ensembles, has been achieved. Currently, an important task towards scalable quantum information processing (QIP) is to efficiently write and read entanglement generated from a SPDC source into and out of an atomic quantum memory. Here we report the first experimental realization of a quantum interface by building a 5 MHz frequency-uncorrelated SPDC source and reversibly mapping the generated entangled photons into and out of a remote optically thick cold atomic memory using electromagnetically induced transparency. The frequency correlation between the entangled photons is almost fully eliminated with a suitable pump pulse. The storage of a triggered single photon with arbitrary polarization is shown to reach an average fidelity of 92% for 200 ns storage time. Moreover, polarization-entangled photon pairs are prepared, and one of photons is stored in the atomic memory while the other keeps flying. The CHSH Bell's inequality is measured and violation is clearly observed for storage time up to 1 microsecond. This demonstrates the entanglement is stored and survives during the storage. Our work establishes a crucial element to implement scalable all-optical QIP, and thus presents a substantial progress in quantum information science.Comment: 28 pages, 4 figures, 1 tabl

    A controllable superconducting electromechanical oscillator with a suspended membrane

    Full text link
    We fabricate a microscale electromechanical system, in which a suspended superconducting membrane, treated as a mechanical oscillator, capacitively couples to a superconducting microwave resonator. As the microwave driving power increases, nonmonotonic dependence of the resonance frequency of the mechanical oscillator on the driving power has been observed. We also demonstrate the optical switching of the resonance frequency of the mechanical oscillator. Theoretical models for qualitative understanding of our experimental observations are presented. Our experiment may pave the way for the application of a mechanical oscillator with its resonance frequency controlled by the electromagnetic and/or optical fields, such as a microwave-optical interface and a controllable element in a superqubit-mechanical oscillator hybrid system.Comment: 8 pages,4 figure
    corecore