1,358 research outputs found
Effects of Phosphorus Accumulation in Soil with the Utilization Ages of the Vegetable Greenhouses in the Suburb of Shenyang
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
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
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
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 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 within 0-5% centrality in the vicinity of
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
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 MeV, the curvature of the transition line
and also a critical end point at 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
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 Ares.Comment: 7 pages, 3 figure
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