A new procedure for designing optimal bounded control of quasi-nonintegrable Hamiltonian systems with actuator saturation is proposed based on the stochastic averaging method for quasi-nonintegrable ...Hamiltonian systems and the stochastic maximum principle. First, the stochastic averaging method for controlled quasi-nonintegrable Hamiltonian systems is introduced. The original control problem is converted into one for a partially averaged equation of system energy together with a partially averaged performance index. Then, the adjoint equation and the maximum condition of the partially averaged control problem are derived based on the stochastic maximum principle. The bounded optimal control forces are obtained from the maximum condition and solving the forward–backward stochastic differential equations (FBSDE). For infinite time-interval ergodic control, the adjoint variable is stationary process, and the FBSDE is reduced to an ordinary differential equation. Finally, the stationary probability density of the Hamiltonian and other response statistics of optimally controlled system are obtained by solving the Fokker–Plank–Kolmogorov equation associated with the fully averaged Itô equation of the controlled system. For comparison, the bang–bang control is also presented. An example of two degree-of-freedom quasi-nonintegrable Hamiltonian system is worked out to illustrate the proposed procedure and its effectiveness. Numerical results show that the proposed control strategy has higher control efficiency and less discontinuous control force than the corresponding bang–bang control at the price of slightly less control effectiveness.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
This Letter reports a measurement of the flux and energy spectrum of electron antineutrinos from six 2.9 GWth nuclear reactors with six detectors deployed in two near (effective baselines 512 and 561 ...m) and one far (1579 m) underground experimental halls in the Daya Bay experiment. Using 217 days of data, 296 721 and 41 589 inverse β decay (IBD) candidates were detected in the near and far halls, respectively. The measured IBD yield is (1.55±0.04) ×10(-18) cm(2) GW(-1) day(-1) or (5.92±0.14) ×10(-43) cm(2) fission(-1). This flux measurement is consistent with previous short-baseline reactor antineutrino experiments and is 0.946±0.022 (0.991±0.023) relative to the flux predicted with the Huber-Mueller (ILL-Vogel) fissile antineutrino model. The measured IBD positron energy spectrum deviates from both spectral predictions by more than 2σ over the full energy range with a local significance of up to ∼4σ between 4-6 MeV. A reactor antineutrino spectrum of IBD reactions is extracted from the measured positron energy spectrum for model-independent predictions.
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A new procedure for designing optimal control of quasi non-integrable Hamiltonian systems under stochastic excitations is proposed based on the stochastic averaging method for quasi non-integrable ...Hamiltonian systems and the stochastic maximum principle. First, the control problem consisting of 2
n
-dimensional equations governing the controlled quasi non-integrable system and performance index is converted into a partially averaged one consisting of one-dimensional equation of the controlled system and performance index by using the stochastic averaging method. Then, the adjoint equation and the maximum condition of the partially averaged control problem are derived based on the stochastic maximum principle. The optimal control forces are determined from the maximum condition and solving the forward–backward stochastic differential equations (FBSDE). For infinite time-interval ergodic control, the adjoint variable is a stationary process and the FBSDE is reduced to a partial differential equation. Finally, the response statistics of optimally controlled system is predicted by solving the Fokker–Plank equation (FPE) associated with the fully averaged Itô equation of the controlled system. An example of two degree-of-freedom (DOF) quasi non-integrable Hamiltonian system is worked out to illustrate the proposed procedure and its effectiveness.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
We investigated the associations between vascular endothelial growth factors (VEGF), endothelial nitric oxide synthase (eNOS), and ATP-binding cassette subfamily B member 1 transporter (ABCB1) ...polymorphisms and the risk of osteonecrosis of the femoral head (ONFH). Published studies were reviewed and analyzed based on predefined selection criteria. The strength of the association between VEGF, eNOS, and ABCB1 polymorphisms and ONFH risk was evaluated based on the odds ratio with corresponding 95%CIs. Meta-analysis was performed using the Comprehensive Meta-analysis 2.0 software. A total of 135 relevant articles were retrieved, of which 10 studies met the selection criteria, and included a total of 1025 patients with ONFH and 1730 healthy controls. The meta-analysis study results revealed that the VEGF rs2010963 G>C polymorphism increased the risk of ONFH, while the VEGF rs2010963 G>C and ABCB1 rs1045642 C>T polymorphisms increased the risk of ONFH under the allele model. In conclusion, the VEGF, eNOS, and ABCB1 polymorphisms may contribute to ONFH, but further studies including larger sample sizes are needed to confirm the results.
To overcome the dendrite formation of metallic lithium anodes, polycrystalline Li3N films are coated on Li foil by an ex-situ nitridation method. The electrochemical performances of the Li3N-modified ...Li electrodes are investigated by galvanostatic charge/discharge tests, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) to determine the optimized nitridation condition. The morphologies and structures for the pure Li and the Li3N-modified Li electrodes, both before and after cycling, are characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The Li3N films on Li surface can efficiently prevent the contact between Li and the electrolyte, and reduce the side reaction, thus suppressing the formation of dendritic lithium effectively.
•Polycrystalline Li3N films are fabricated on Li foil by nitridation method.•The Li3N/Li electrodes show preferable electrochemical performances.•The optimal nitridation condition of Li3N/Li electrodes is obtained.•The Li3N film can prevent the contact between Li and the electrolyte efficiently.•Dendritic growth is suppressed significantly according to the SEM photograph.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
A compact wideband filter with a wide upper stopband using stub-loaded multiple-mode resonators is designed. The multimode behaviour and characteristics of the proposed filter structure are studied ...by conventional natural modes analysis. A prototype is designed and fabricated at 1 GHz (f0) with 3 dB fractional bandwidths 102% and 20 dB stopband attenuation up to 10.75f0. Good agreement between simulations and experiments is observed.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Non-polar (1
1
2¯
0)
a-plane GaN films have been grown by low-pressure metal-organic vapor deposition on
r-plane (1
1¯
0
2) sapphire substrate. We report on an approach of using AlN/AlGaN ...superlattices (SLs) for crystal quality improvement of
a-plane GaN on
r-plane sapphire. Using X-ray diffraction and atomic force microscopy measurements, we show that the insertion of AlN/AlGaN SLs improves crystal quality, reduces surface roughness effectively and eliminates triangular pits on the surface completely.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Lily (Lilium spp), which belongs to Lilium, is one kind of monocotyledon. As a perennial ornamental plant with extremely high esthetic, edible, and medicinal value, lily has gained much favor due to ...its mostly showy flowers of various colors and elegant shape. In this research, we studied experimental materials in a sample of 49 individuals including 40 cultivars, nine species of wild lily, and their variants. The collection of 40 cultivars covered all six hybrids in the genus, i.e., Asiatic hybrids, Oriental hybrids, Longiflorum hybrids, LA hybrids, LO hybrids, and OT hybrids. Genetic diversity and inter-relationships were assessed through analysis of phenotypic characteristics, pollen morphology, and ISSR molecular markers. Quantitative characters were selected to analyze phenotypic variation, with results indicating greater variability in petiole length as compared to other characters. Pollen morphological observations suggested that the largest variation coefficient between all hybrids and wild species was the lumina. ISSR makers demonstrated that both cultivars and wild species possess a high level of genetic diversity. Specifically, the genetic diversity of wild lily was higher than cultivars.
A search for light sterile neutrino mixing was performed with the first 217 days of data from the Daya Bay Reactor Antineutrino Experiment. The experiment's unique configuration of multiple baselines ...from six 2.9 GW(th) nuclear reactors to six antineutrino detectors deployed in two near (effective baselines 512 m and 561 m) and one far (1579 m) underground experimental halls makes it possible to test for oscillations to a fourth (sterile) neutrino in the 10(-3) eV(2)<|Δm(41)(2) |< 0.3 eV(2) range. The relative spectral distortion due to the disappearance of electron antineutrinos was found to be consistent with that of the three-flavor oscillation model. The derived limits on sin(2) 2θ(14) cover the 10(-3) eV(2) ≲ |Δm(41)(2)| ≲ 0.1 eV(2) region, which was largely unexplored.
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