The oxygen fluxe across the sediment-water interface(SWI)in coastal region is a key measure to fully understand the regulation of biogeochemical cycles in an aquatic environment.However,studies on fluxes of dissolved ...The oxygen fluxe across the sediment-water interface(SWI)in coastal region is a key measure to fully understand the regulation of biogeochemical cycles in an aquatic environment.However,studies on fluxes of dissolved oxygen in gravel beach are limited,because of the difficulty in sample collection and instrumentations deployment.In this study,benthic oxygen fluxes across rocky substratum in an intertidal zone of Huiquan Bay was estimated by using noninvasive eddy correlation techniques.A total of 10 burst measurements were analyzed.The oxygen flux fluctuated from-5.7888±2.6 to+49.3344±2.6 mmol O2 m-2/d were observed.The cospectra analysis showed that the oxygen flux at the frequency band between 0.093 and 0.279 Hz(at a period from 3.58 to 10.75 s)contributed 50.19%to the total spectrum on average.The results showed that the major contribution band moved to the high frequency region gradually and reached a steady state with increasing tidal flood.It is demonstrated that wave movement and wave breaking interaction resulted in the change of oxygen flux between gravel beach and shallow waters at the start and the end of a rising tide period,respectively.The eddy correlation techniques offer an efficient means for flux measurement over a gravel or mixed sand and gravel beaches.展开更多
In this article we describe a range of simulations (lattice dynamics and molecular dynamics) of the inelastic incoherent neutron scattering spectra of ices (normal ice, ice Ⅱ and ice Ⅷ). These simulations use a vari...In this article we describe a range of simulations (lattice dynamics and molecular dynamics) of the inelastic incoherent neutron scattering spectra of ices (normal ice, ice Ⅱ and ice Ⅷ). These simulations use a variety of different intermolecular potentials from simple classic pair-wise (rigid and non-rigid molecule) potentials to sophisticated polarisable potentials. It was found that MCY makes stretching and bending interactions too weak while others do them well. We demonstrate that in order to reproduce the measured neutron spectrum, greater anisotropy (or orientational variation) is required than these potentials presently provide.展开更多
基金Funding for this work was supported by the National Natural Science Foundation of China (Nos. 41276089, 41176078)the National High-technology research and development Program of China (‘863’Program) (Nos. 2012AA09A20103, 2009AA09Z201)
文摘The oxygen fluxe across the sediment-water interface(SWI)in coastal region is a key measure to fully understand the regulation of biogeochemical cycles in an aquatic environment.However,studies on fluxes of dissolved oxygen in gravel beach are limited,because of the difficulty in sample collection and instrumentations deployment.In this study,benthic oxygen fluxes across rocky substratum in an intertidal zone of Huiquan Bay was estimated by using noninvasive eddy correlation techniques.A total of 10 burst measurements were analyzed.The oxygen flux fluctuated from-5.7888±2.6 to+49.3344±2.6 mmol O2 m-2/d were observed.The cospectra analysis showed that the oxygen flux at the frequency band between 0.093 and 0.279 Hz(at a period from 3.58 to 10.75 s)contributed 50.19%to the total spectrum on average.The results showed that the major contribution band moved to the high frequency region gradually and reached a steady state with increasing tidal flood.It is demonstrated that wave movement and wave breaking interaction resulted in the change of oxygen flux between gravel beach and shallow waters at the start and the end of a rising tide period,respectively.The eddy correlation techniques offer an efficient means for flux measurement over a gravel or mixed sand and gravel beaches.
基金We would like to thank National Natural Science Foundation of China(Grand No.10144001)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry,for their financial supports.
文摘In this article we describe a range of simulations (lattice dynamics and molecular dynamics) of the inelastic incoherent neutron scattering spectra of ices (normal ice, ice Ⅱ and ice Ⅷ). These simulations use a variety of different intermolecular potentials from simple classic pair-wise (rigid and non-rigid molecule) potentials to sophisticated polarisable potentials. It was found that MCY makes stretching and bending interactions too weak while others do them well. We demonstrate that in order to reproduce the measured neutron spectrum, greater anisotropy (or orientational variation) is required than these potentials presently provide.
