A measurement of electron antineutrino oscillation by the Daya Bay Reactor Neutrino Experiment is described in detail. Six 2.9-GW\(_{\rm th}\) nuclear power reactors of the Daya Bay and Ling Ao ...nuclear power facilities served as intense sources of \(\overline{\nu}_{e}\)'s. Comparison of the \(\overline{\nu}_{e}\) rate and energy spectrum measured by antineutrino detectors far from the nuclear reactors (\(\sim\)1500-1950 m) relative to detectors near the reactors (\(\sim\)350-600 m) allowed a precise measurement of \(\overline{\nu}_{e}\) disappearance. More than 2.5 million \(\overline{\nu}_{e}\) inverse beta decay interactions were observed, based on the combination of 217 days of operation of six antineutrino detectors (Dec. 2011--Jul. 2012) with a subsequent 1013 days using the complete configuration of eight detectors (Oct. 2012--Jul. 2015). The \(\overline{\nu}_{e}\) rate observed at the far detectors relative to the near detectors showed a significant deficit, \(R=0.949 \pm 0.002(\mathrm{stat.}) \pm 0.002(\mathrm{syst.})\). The energy dependence of \(\overline{\nu}_{e}\) disappearance showed the distinct variation predicted by neutrino oscillation. Analysis using an approximation for the three-flavor oscillation probability yielded the flavor-mixing angle \(\sin^22\theta_{13}=0.0841 \pm 0.0027(\mathrm{stat.}) \pm 0.0019(\mathrm{syst.})\) and the effective neutrino mass-squared difference of \(\left|{\Delta}m^2_{\mathrm{ee}}\right|=(2.50 \pm 0.06(\mathrm{stat.}) \pm 0.06(\mathrm{syst.})) \times 10^{-3}\ {\rm eV}^2\). Analysis using the exact three-flavor probability found \({\Delta}m^2_{32}=(2.45 \pm 0.06(\mathrm{stat.}) \pm 0.06(\mathrm{syst.})) \times 10^{-3}\ {\rm eV}^2\) assuming the normal neutrino mass hierarchy and \({\Delta}m^2_{32}=(-2.56 \pm 0.06(\mathrm{stat.}) \pm 0.06(\mathrm{syst.})) \times 10^{-3}\ {\rm eV}^2\) for the inverted hierarchy.
This Letter reports an improved search for light sterile neutrino mixing in the electron antineutrino disappearance channel with the full configuration of the Daya Bay Reactor Neutrino Experiment. ...With an additional 404 days of data collected in eight antineutrino detectors, this search benefits from 3.6 times the statistics available to the previous publication, as well as from improvements in energy calibration and background reduction. A relative comparison of the rate and energy spectrum of reactor antineutrinos in the three experimental halls yields no evidence of sterile neutrino mixing in the \(2\times10^{-4} \lesssim |\Delta m^{2}_{41}| \lesssim 0.3\) eV\(^{2}\) mass range. The resulting limits on \(\sin^{2}2\theta_{14}\) are improved by approximately a factor of 2 over previous results and constitute the most stringent constraints to date in the \(|\Delta m^{2}_{41}| \lesssim 0.2\) eV\(^{2}\) region.
The origin of enhanced superconductivity over 50 K in the recently discovered FeSe monolayer films grown on SrTiO
(STO), as compared to 8 K in bulk FeSe, is intensely debated. As with the ...ferrochalcogenides A
Fe
Se
and potassium-doped FeSe, which also have a relatively high-superconducting critical temperature (T
), the Fermi surface (FS) of the FeSe/STO monolayer films is free of hole-like FS, suggesting that a Lifshitz transition by which these hole FSs vanish may help increasing T
. However, the fundamental reasons explaining this increase of T
remain unclear. Here we report a 15 K jump of T
accompanying a second Lifshitz transition characterized by the emergence of an electron pocket at the Brillouin zone centre, which is triggered by high-electron doping following in situ deposition of potassium on FeSe/STO monolayer films. Our results suggest that the pairing interactions are orbital dependent in generating enhanced superconductivity in FeSe.
Recently, to ensure the reliability and safety of modern large-scale industrial processes, data-driven methods have been receiving considerably increasing attention, particularly for the purpose of ...process monitoring. However, great challenges are also met under different real operating conditions by using the basic data-driven methods. In this paper, widely applied data-driven methodologies suggested in the literature for process monitoring and fault diagnosis are surveyed from the application point of view. The major task of this paper is to sketch a basic data-driven design framework with necessary modifications under various industrial operating conditions, aiming to offer a reference for industrial process monitoring on large-scale industrial processes.
Using gas chromatography mass spectrometry and the PacBio single molecule with real-time sequencing technology (SMRT), we analyzed the detailed metabolomic profiles and microbial community dynamics ...involved in ensiled Medicago sativa (alfalfa) inoculated without or with the homofermenter Lactobacillus plantarum or heterofermenter Lactobacillus buchneri. Our results revealed that 280 substances and 102 different metabolites were present in ensiled alfalfa. Inoculation of L. buchneri led to remarkable up-accumulation in concentrations of 4-aminobutyric acid, some free amino acids, and polyols in ensiled alfalfa, whereas considerable down-accumulation in cadaverine and succinic acid were observed in L. plantarum-inoculated silages. Completely different microbial flora and their successions during ensiling were observed in the control and two types of inoculant-treated silages. Inoculation of the L. plantarum or L. buchneri alters the microbial composition dynamics of the ensiled forage in very different manners. Our study demonstrates that metabolomic profiling analysis provides a deep insight in metabolites in silage. Moreover, the PacBio SMRT method revealed the microbial composition and its succession during the ensiling process at the species level. This provides information regarding the microbial processes underlying silage formation and may contribute to target-based regulation methods to achieve high-quality silage production.
The disappearance of reactor \(\bar{\nu}_e\) observed by the Daya Bay experiment is examined in the framework of a model in which the neutrino is described by a wave packet with a relative intrinsic ...momentum dispersion \(\sigma_\text{rel}\). Three pairs of nuclear reactors and eight antineutrino detectors, each with good energy resolution, distributed among three experimental halls, supply a high-statistics sample of \(\bar{\nu}_e\) acquired at nine different baselines. This provides a unique platform to test the effects which arise from the wave packet treatment of neutrino oscillation. The modified survival probability formula was used to fit Daya Bay data, providing the first experimental limits: \(2.38 \cdot 10^{-17} < \sigma_{\rm rel} < 0.23\). Treating the dimensions of the reactor cores and detectors as constraints, the limits are improved: \(10^{-14} \lesssim \sigma_{\rm rel} < 0.23\), and an upper limit of \(\sigma_{\rm rel} <0.20\) is obtained. All limits correspond to a 95\% C.L. Furthermore, the effect due to the wave packet nature of neutrino oscillation is found to be insignificant for reactor antineutrinos detected by the Daya Bay experiment thus ensuring an unbiased measurement of the oscillation parameters \(\sin^22\theta_{13}\) and \(\Delta m^2_{32}\) within the plane wave model.
Recently, the first ever 100 s long, steady-state H-mode discharge with good control of impurities, core and edge MHD stabilities, and heat exhaust was demonstrated in the Experimental Advanced ...Superconducting Tokamak (EAST) using the ITER-like (International Tokamak Experimental Reactor) tungsten upper divertor. Using both radio frequency (RF) power and neutral beam injection (NBI) heating, EAST has demonstrated fully non-inductive scenarios with an extension of fusion performance at high density and low rotation: βP ∼ 2.5, βN ∼ 2.0, H98,y2 ∼ 1.2, bootstrap current fraction fBS ∼50% at q95 ∼ 6.8. With pure RF power heating, plasmas have been maintained for up to 21 s (over 40 times the current relaxation time) with zero loop voltage and small edge localized modes (ELMs) at high density (ne/nGW ∼ 0.6-0.8), βP ∼ 2.0, βN ∼ 1.6, and ƒBS ∼47%. Experimental investigations show how plasma current profiles, turbulent transport and radiation properties self-consistently evolve toward fusion relevant steady state conditions. Modeling and physics experiments have confirmed the synergistic effects between electron cyclotron heating (ECH) and low hybrid wave (LHW), where ECH enhances the heating and current drive from LHW injection, enabling fully non-inductive operation at higher density. Small/no ELMs facilitate the RF power coupling in the H-mode phase and reduce divertor erosion. A low tungsten concentration was observed at high βP with a hollow profile in the core. Reduction of the peak divertor heat flux with frad of up to 40% was compatible with the high βP scenario by using active radiation feedback control. With features such as dominant electron heating, zero/low NBI torque and an ITER-like tungsten divertor, fully non-inductive high-performance experiments on EAST offer unique contributions towards the succesful operation of ITER and CFETR (the Chinese Fusion Engineering Testing Reactor).
Superelastic conducting fibers with improved properties and functionalities are needed for diverse applications. Here we report the fabrication of highly stretchable (up to 1320%) sheath-core ...conducting fibers created by wrapping carbon nanotube sheets oriented in the fiber direction on stretched rubber fiber cores. The resulting structure exhibited distinct short- and long-period sheath buckling that occurred reversibly out of phase in the axial and belt directions, enabling a resistance change of less than 5% for a 1000% stretch. By including other rubber and carbon nanotube sheath layers, we demonstrated strain sensors generating an 860% capacitance change and electrically powered torsional muscles operating reversibly by a coupled tension-to-torsion actuation mechanism. Using theory, we quantitatively explain the complementary effects of an increase in muscle length and a large positive Poisson's ratio on torsional actuation and electronic properties.
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