545 research outputs found

    Effect of anaerobic fermentation residues on a chromium-contaminated soil-vegetable system

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    AbstractWastewater irrigation and the deposit of chromium residues during the course of chromate production had caused serious chromium pollution in farmland. The aim of this study was to use anaerobic fermentation residues to treat with a chromium-contaminated soil-vegetable system. Pot experiment with Chinese cabbage, indoor cultivation experiment and soil adsorption experiments were conducted in this study. The results indicated that both yields and residual chromium in Chinese cabbages with the treatment of anaerobic fermentation residues were generally better than that with the treatment of chemical fertilizer. At the second experiment, compared with raw soil, mineralized potential and mineralized rate of nitrogen increased 29.2% and 15.4% respectively after adding anaerobic fermentation residues. Experimental results were fitted to Langmuir equation, Freundlich equation and Temkin equation, Langmuir equation was found to be the best to describe the adsorption of phosphor, and Temkin equation was the fittest for describing the adsorption of potassium. The supply of nitrogen, phosphor and potassium from soil were enhanced in varying degree (nitrogen > phosphor >potassium). Thus anaerobic fermentation residues may be considered as a widespread, effective and safe strategy for deal with chromium-contaminated soil-vegetable system in future

    Study on the effect of biogas project on the development of lowcarbon circular economy -A case study of Beilangzhong eco-village

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    AbstractWith Beilangzhong eco-village as an example, the effects of the biogas project on the reduction of greenhouse gas (GHG) emission and its economic effects are analyzed. The results show that 1833.45t GHG (CO2 equivalent) was reduced, and an income of 1,117,000 Yuan (RMB), a net income of 958,500 Yuan (RMB), was gained by biogas sales, alternative energy, comprehensive utilization of anaerobic fermentation residues and the reduction of GHG emission, so the biogas project can greatly promote the establishment of low-carbon circular economy mode and sustainable development of ecological agriculture in Beilangzhong eco-village

    Bs(d)0−Bˉs(d)0B^0_{s(d)} - \bar{B}^0_{s(d)} mixing and new physics effects in a top quark two-Higgs doublet model

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    We calculate the new physics contributions to the neutral Bd0B_d^0 and Bs0B_s^0 meson mass splitting ΔMd\Delta M_d and ΔMs\Delta M_s induced by the box diagrams involving the charged-Higgs bosons in the top quark two-Higgs doublet model (T2HDM). Using the precision data, we obtain the bounds on the parameter space of the T2HDM: (a) for fixed MH=400M_H=400 GeV and ÎŽ=[0∘,60∘]\delta=[0^\circ,60^\circ], the upper bound on tan⁥ÎČ\tan{\beta} is tan⁥ÎČ≀30\tan \beta \leq 30 after the inclusion of major theoretical uncertainties; (b) for the case of tan⁥ÎČ≀20\tan{\beta} \leq 20, a light charged Higgs boson with a mass around 300 GeV is allowed; and (c) the bounds on tan⁥ÎČ\tan{\beta} and MHM_H are strongly correlated: a smaller (larger) tan⁥ÎČ\tan{\beta} means a lighter (heavier) charged Higgs boson.Comment: 11 pages, 2 EPS figures, RevTex, new references adde

    A new ghost cell/level set method for moving boundary problems:application to tumor growth

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    In this paper, we present a ghost cell/level set method for the evolution of interfaces whose normal velocity depend upon the solutions of linear and nonlinear quasi-steady reaction-diffusion equations with curvature-dependent boundary conditions. Our technique includes a ghost cell method that accurately discretizes normal derivative jump boundary conditions without smearing jumps in the tangential derivative; a new iterative method for solving linear and nonlinear quasi-steady reaction-diffusion equations; an adaptive discretization to compute the curvature and normal vectors; and a new discrete approximation to the Heaviside function. We present numerical examples that demonstrate better than 1.5-order convergence for problems where traditional ghost cell methods either fail to converge or attain at best sub-linear accuracy. We apply our techniques to a model of tumor growth in complex, heterogeneous tissues that consists of a nonlinear nutrient equation and a pressure equation with geometry-dependent jump boundary conditions. We simulate the growth of glioblastoma (an aggressive brain tumor) into a large, 1 cm square of brain tissue that includes heterogeneous nutrient delivery and varied biomechanical characteristics (white matter, gray matter, cerebrospinal fluid, and bone), and we observe growth morphologies that are highly dependent upon the variations of the tissue characteristics—an effect observed in real tumor growth

    Measurement of W Polarisation at LEP

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    The three different helicity states of W bosons produced in the reaction e+ e- -> W+ W- -> l nu q q~ at LEP are studied using leptonic and hadronic W decays. Data at centre-of-mass energies \sqrt s = 183-209 GeV are used to measure the polarisation of W bosons, and its dependence on the W boson production angle. The fraction of longitudinally polarised W bosons is measured to be 0.218 \pm 0.027 \pm 0.016 where the first uncertainty is statistical and the second systematic, in agreement with the Standard Model expectation

    Search for Anomalous Couplings in the Higgs Sector at LEP

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    Anomalous couplings of the Higgs boson are searched for through the processes e^+ e^- -> H gamma, e^+ e^- -> e^+ e^- H and e^+ e^- -> HZ. The mass range 70 GeV < m_H < 190 GeV is explored using 602 pb^-1 of integrated luminosity collected with the L3 detector at LEP at centre-of-mass energies sqrt(s)=189-209 GeV. The Higgs decay channels H -> ffbar, H -> gamma gamma, H -> Z\gamma and H -> WW^(*) are considered and no evidence is found for anomalous Higgs production or decay. Limits on the anomalous couplings d, db, Delta(g1z), Delta(kappa_gamma) and xi^2 are derived as well as limits on the H -> gamma gamma and H -> Z gamma decay rates

    Measurement of W Polarisation at LEP

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    The three different helicity states of W bosons produced in the reaction e+ e- -> W+ W- -> l nu q q~ at LEP are studied using leptonic and hadronic W decays. Data at centre-of-mass energies \sqrt s = 183-209 GeV are used to measure the polarisation of W bosons, and its dependence on the W boson production angle. The fraction of longitudinally polarised W bosons is measured to be 0.218 \pm 0.027 \pm 0.016 where the first uncertainty is statistical and the second systematic, in agreement with the Standard Model expectation

    Neutral-Current Four-Fermion Production in e+e- Interactions at LEP

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    Neutral-current four-fermion production, e+e- -> ffff is studied in 0.7/fb of data collected with the L3 detector at LEP at centre-of-mass energies root(s)=183-209GeV. Four final states are considered: qqvv, qqll, llll and llvv, where l denotes either an electron or a muon. Their cross sections are measured and found to agree with the Standard Model predictions. In addition, the e+e- -> Zgamma* -> ffff process is studied and its total cross section at the average centre-of-mass energy 196.6GeV is found to be 0.29 +/- 0.05 +/- 0.03 pb, where the first uncertainty is statistical and the second systematic, in agreement with the Standard Model prediction of 0.22 pb. Finally, the mass spectra of the qqll final states are analysed to search for the possible production of a new neutral heavy particle, for which no evidence is found

    Measurement of Exclusive rho+rho- Production in Mid-Virtuality Two-Photon Interactions and Study of the gamma gamma* -> rho rho Process at LEP

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    Exclusive rho+rho- production in two-photon collisions between a quasi-real photon, gamma, and a mid-virtuality photon, gamma*, is studied with data collected at LEP at centre-of-mass energies root(s)=183-209GeV with a total integrated luminosity of 684.8pb^-1. The cross section of the gamma gamma* -> rho+ rho- process is determined as a function of the photon virtuality, Q^2, and the two-photon centre-of-mass energy, W_gg, in the kinematic region: 0.2GeV^2 < Q^2 <0.85GeV^2 and 1.1GeV < W_gg < 3GeV. These results, together with previous L3 measurements of rho0 rho0 and rho+ rho- production, allow a study of the gamma gamma* -> rho rho process over the Q^2-region 0.2GeV^2 < Q^2 < 30 GeV^2
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