1,358 research outputs found

    Effects of Phosphorus Accumulation in Soil with the Utilization Ages of the Vegetable Greenhouses in the Suburb of Shenyang

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    AbstractThe accumulation of phosphorus in different utilization age (0, 1, 2, 3, 5, 13-year) vegetable greenhouses soil with multi-point mixed samples was examined in Damintun Town of Shenyang. The results showed that the content of P of all samples was increased with the utilization ages of the vegetable greenhouses. For all the samples, the concentration of TP and Olsen-P in the 0-40cm layer was higher than that in the 40-120cm. Compared with other samples, the content of TP and Olsen-P of 13 years of vegetable greenhouse soil is the highest throughout the 0-120cm. In the 0-20cm layer, the TP concentrations in 13-year vegetable greenhouse soil is 4 times higher than that in the open vegetable land, and the concentration of Olsen-P range from 23.87mg kg-1 in bare land soil to 102.13mg kg-1 in 13-year vegetable greenhouse soil. These results demonstrated that long-term continuous P input from chemical fertilizers and manure can cause P accumulation in soils and enrich in topsoil

    Speech Dereverberation Based on Integrated Deep and Ensemble Learning Algorithm

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    Reverberation, which is generally caused by sound reflections from walls, ceilings, and floors, can result in severe performance degradation of acoustic applications. Due to a complicated combination of attenuation and time-delay effects, the reverberation property is difficult to characterize, and it remains a challenging task to effectively retrieve the anechoic speech signals from reverberation ones. In the present study, we proposed a novel integrated deep and ensemble learning algorithm (IDEA) for speech dereverberation. The IDEA consists of offline and online phases. In the offline phase, we train multiple dereverberation models, each aiming to precisely dereverb speech signals in a particular acoustic environment; then a unified fusion function is estimated that aims to integrate the information of multiple dereverberation models. In the online phase, an input utterance is first processed by each of the dereverberation models. The outputs of all models are integrated accordingly to generate the final anechoic signal. We evaluated the IDEA on designed acoustic environments, including both matched and mismatched conditions of the training and testing data. Experimental results confirm that the proposed IDEA outperforms single deep-neural-network-based dereverberation model with the same model architecture and training data

    QCD equation of state and thermodynamic observables from computationally minimal Dyson-Schwinger Equations

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    We study the QCD equation of state and other thermodynamic observables including the isentropic trajectories and the speed of sound. These observables are of eminent importance for the understanding of experimental results in heavy ion collisions and also provide a QCD input for studies of the timeline of heavy-ion-collisions with hydrodynamical simulations. They can be derived from the quark propagator whose gap equation is solved within a minimal approximation to the Dyson-Schwinger equations of QCD at finite temperature and density. This minimal approximation aims at a combination of computational efficiency and simplification of the truncation scheme while maintaining quantitative precision. This minimal DSE scheme is confronted and benchmarked with results for correlation functions and observables from first principles QCD lattice at vanishing density and quantitative functional approaches at finite density.Comment: 14 pages, 13 figure

    Revealing the Signal of QCD Phase Transition in Heavy-Ion Collisions

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    We propose a novel method to construct the Landau thermodynamic potential directly from the fluctuations measured in heavy-ion collisions. The potential is capable of revealing the signal of the critical end-point (CEP) and the first order phase transition (FOPT) of QCD in the system even away from the phase transition region. With the available experimental data, we show that the criterion of the FOPT is negative for most of the collision energies which indicates no signal of FOPT. The data at sNN=7.7\sqrt{s_\mathrm{NN}}=7.7 GeV with 0-5% centrality shows a different behavior and the mean value of the data satisfies the criterion. However, the uncertainty is still too large to make a certain conclusion. The higher order fluctuations are also required for confirming the signal. We emphasize therefore that new measurements with higher precision for the C1,...,6C_{1,...,6} within 0-5% centrality in the vicinity of sNN=7.7\sqrt{s_\mathrm{NN}}=7.7 GeV are in demand which may finally reveal the signal of QCD phase transition.Comment: 7 pages, 4 figure

    Constructing the Equation of State of QCD in a functional QCD based scheme

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    We construct the equation of state (EoS) of QCD based on the finite chemical potential information from the functional QCD approaches, with the assistance of the lattice QCD EoS. The obtained EoS is consistent with the up-to-date estimations of the QCD phase diagram, including a phase transition temperature at zero chemical potential of T=155T=155 MeV, the curvature of the transition line κ=0.016\kappa=0.016 and also a critical end point at (T,μB)=(118,600)(T,\mu_B)=(118, 600) MeV. In specific, the phase diagram mapping is achieved by incorporating the order parameters into the EoS, namely the dynamical quark mass for the chiral phase transition together with the Polyakov loop parameter for the deconfinement phase transition. We also implement the EoS in hydrodynamic simulations to compute the particle yields, ratios and collective flow, and find that our obtained EoS agrees well with the commonly used one based on the combination of lattice QCD simulation and hadron resonance gas model.Comment: 8 pages, 12 figure

    Sphaleron freeze-in baryogenesis with gravitational waves from the QCD transition

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    A large primordial lepton asymmetry is capable of explaining the baryon asymmetry of the Universe (BAU) through suppression of the electroweak sphaleron rates (``sphaleron freeze-in") which can lead to a first-order cosmic QCD transition with an observable gravitational wave (GW) signal. With next-to-leading order dimensional reduction and the exact 1-loop fluctuation determinant, we accurately compute the lepton asymmetry needed to realize this paradigm, finding it to be an order of magnitude smaller than previous estimates. Further, we apply an improved QCD equation of state capable of describing the phase transition line together with the critical endpoint leading to better agreement with lattice and functional QCD results. Based on this, we identify the range of lepton flavor asymmetries inducing a first-order cosmic QCD transition. We then extract the parameters relevant to the prediction of GW signal from a first-order cosmic QCD transition. Our result showcases the possibility of probing the sphaleron freeze-in paradigm as an explanation of BAU by future gravitational wave experiments like μ\muAres.Comment: 7 pages, 3 figure
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