Coherent dynamics and decoherence in a superconducting weak link

We demonstrate coherent dynamics of quantized magnetic fluxes in a superconducting loop with a weak link - a nanobridge patterned from the same thin NbN film as the loop. The bridge is a short rounded shape constriction, close to 10 nm long and 20 - 30 nm wide, having minimal width at its center. Quantum state control and coherent oscillations in the driven time evolution of the tunnel-junctionless system are achieved. Decoherence and energy relaxation in the system are studied using a combination of microwave spectroscopy and direct time-domain techniques. The effective flux noise behavior suggests inductance fluctuations as a possible cause of the decoherence.Comment: 5 pages, 3 figure

Hot air drying characteristics and nutrients of apricot armeniaca vulgaris lam pretreated with Radio Frequency(RF)

[EN] Apricot pretreated with RF and then dried with convective hot air at 65℃, 3.0m/s in this research. RF pretreatment time of 20, 30, 40 and 50min were chosen. Results showed that, there is only falling rate period during apricot hot air drying, and the drying rate of apricot is improved significantly; Herdenson and Pabis model is suitable for apricot hot air drying; retentions of flavonoids, polyphenols and Vc in dried apricot were higher than those of fresh apricot; when RF treating time was chosen 30mins, nutrients retentions of Vc, flavonoid and polyphenols were 0.9543mg/100g, 5.4089mg/100g and 7.3382mg/100g, separately.The work was financially supported by the Fundamental Research Funds for the Central Universities of China (NO. GK201503072 and GK201601007).Peng, M.; Liu, J.; Lei, Y.; Yang, X.; Wu, Z.; Huang, X. (2018). Hot air drying characteristics and nutrients of apricot armeniaca vulgaris lam pretreated with Radio Frequency(RF). En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 1583-1590. https://doi.org/10.4995/IDS2018.2018.7524OCS1583159

New rosette tools for developing rotational vibration-assisted incremental sheet forming

A major limitation of the incremental sheet forming (ISF) is its difficulties to manufacture hard-to-form materials. The existing ISF process variants require additional systems or devices, which compromises the process flexibility and simplicity, the unique advantages of the ISF. In this study, a novel type of rosette tools is proposed for developing a new ISF process to improve material formability, named as Rotational Vibration-assisted ISF (RV-ISF). A hard-to-form material, magnesium alloy AZ31B, has been successfully formed in the RV-ISF experiment by creating low-frequency and low-amplitude vibrations, and elevated temperatures at the local forming zone in the range of 250–450 °C. By developing the new RV-ISF, it has achieved a 60% increase in fracture depth than that by friction-stir ISF and more than 46% reduction in forming force than that by the conventional ISF. Experimental evaluation and analytical prediction of temperature increase, forming force and flow-stress reduction have concluded that the combined thermal effect and vibration softening is the key mechanism leading to the significant formability enhancement. The results show that both the rosette tool design and tool rotational speed are critical factors determining heat generation and transfer as well as vibration frequency and amplitude. Investigation on microstructural evolution has revealed that the low-frequency and low-amplitude vibrations created by the rosette tool have activated dislocations and dynamic recrystallization, and produced refined grains and increased micro hardness. The new RV-ISF developed has potentials to manufacture other hard-to-form materials and complex geometries of sheet products, overcoming the formability limitation of the current ISF technology

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

Measurement of the View the tt production cross-section using eμ events with b-tagged jets in pp collisions at √s = 13 TeV with the ATLAS detector

This paper describes a measurement of the inclusive top quark pair production cross-section (σtt¯) with a data sample of 3.2 fb−1 of proton–proton collisions at a centre-of-mass energy of √s = 13 TeV, collected in 2015 by the ATLAS detector at the LHC. This measurement uses events with an opposite-charge electron–muon pair in the final state. Jets containing b-quarks are tagged using an algorithm based on track impact parameters and reconstructed secondary vertices. The numbers of events with exactly one and exactly two b-tagged jets are counted and used to determine simultaneously σtt¯ and the efficiency to reconstruct and b-tag a jet from a top quark decay, thereby minimising the associated systematic uncertainties. The cross-section is measured to be: σtt¯ = 818 ± 8 (stat) ± 27 (syst) ± 19 (lumi) ± 12 (beam) pb, where the four uncertainties arise from data statistics, experimental and theoretical systematic effects, the integrated luminosity and the LHC beam energy, giving a total relative uncertainty of 4.4%. The result is consistent with theoretical QCD calculations at next-to-next-to-leading order. A fiducial measurement corresponding to the experimental acceptance of the leptons is also presented

Search for strong gravity in multijet final states produced in pp collisions at √s=13 TeV using the ATLAS detector at the LHC

A search is conducted for new physics in multijet final states using 3.6 inverse femtobarns of data from proton-proton collisions at √s = 13TeV taken at the CERN Large Hadron Collider with the ATLAS detector. Events are selected containing at least three jets with scalar sum of jet transverse momenta (HT) greater than 1TeV. No excess is seen at large HT and limits are presented on new physics: models which produce final states containing at least three jets and having cross sections larger than 1.6 fb with HT > 5.8 TeV are excluded. Limits are also given in terms of new physics models of strong gravity that hypothesize additional space-time dimensions