Using the asymptotic iteration method, we obtain the S-wave solution for a short-range three-parameter central potential with 1/r singularity and with a non-orbital barrier. To the best of our knowledge, this is the f...Using the asymptotic iteration method, we obtain the S-wave solution for a short-range three-parameter central potential with 1/r singularity and with a non-orbital barrier. To the best of our knowledge, this is the first attempt at calculating the energy spectrum for this potential, which was introduced by H. Bahlouli and A. D. Alhaidari and for which they obtained the “potential parameter spectrum”. Our results are also independently verified using a direct method of diagonalizing the Hamiltonian matrix in the J-matrix basis.展开更多
Multispecies ecological models have been used for predicting the effects of fishing activity and evaluating the performance of management strategies. Size-spectrum models are one type of physiologically-structured eco...Multispecies ecological models have been used for predicting the effects of fishing activity and evaluating the performance of management strategies. Size-spectrum models are one type of physiologically-structured ecological model that provide a feasible approach to describing fish communities in terms of individual dietary variation and ontogenetic niche shift. Despite the potential of ecological models in improving our understanding of ecosystems, their application is usually limited for data-poor fisheries. As a first step in implementing ecosystem-based fisheries management(EBFM), this study built a size-spectrum model for the fish community in the Haizhou Bay, China. We describe data collection procedures and model parameterization to facilitate the implementation of such size-spectrum models for future studies of data-poor ecosystems. The effects of fishing on the ecosystem were exemplified with a range of fishing effort and were monitored with a set of ecological indicators. Total community biomass, biodiversity index, W-statistic, LFI(Large fish index), Mean W(mean body weight) and Slope(slope of community size spectra) showed a strong non-linear pattern in response to fishing pressure, and largest fishing effort did not generate the most drastic responses in certain scenarios. We emphasize the value and feasibility of developing size-spectrum models to capture ecological dynamics and suggest limitations as well as potential for model improvement. This study aims to promote a wide use of this type of model in support of EBFM.展开更多
On the basis of previous parameterization schemes, considering both the wave breaking and absorbed at critical level, a parameterization with a continuous spectrum of gravity waves is realized by introducing a momentu...On the basis of previous parameterization schemes, considering both the wave breaking and absorbed at critical level, a parameterization with a continuous spectrum of gravity waves is realized by introducing a momentum flux density function for the wave spectrum, and then the parameterization scheme of the gravity waves is improved. Choosing parameter values of the background atmosphere and waves based on the observations, a more realistic equatorial quasi-biennial oscillation (QBO) driven by the incorporated drag from the planetary and gravity waves can be simulated. The numerical results indicate that the forcing magnitude of the planetary and gravity waves varies with the wind field, and in some phases of the QBO, the contribution of the gravity waves is comparable with that of the planetary waves. After the QBO is steadily formed, its amplitude and period and wind configuration are relevant to the effect of vertical diffusion and the momentum flux distribution with spectrum, however, independent of the initial background wind field. Moreover, for any given nonzero initial background wind, a steady QBO can be finally generated due to the incorporated drag from the planetary and gravity waves.展开更多
To study the mechanism of Cu toxicity on wheat,the characteristics of Cu stress in pivotal growth periods of wheat were explored by field planting methods.The results showed that at the tillering stage,the concentrati...To study the mechanism of Cu toxicity on wheat,the characteristics of Cu stress in pivotal growth periods of wheat were explored by field planting methods.The results showed that at the tillering stage,the concentrations of Cu in the leaf cell fluid were significantly higher than those in the cell wall,and the Cu was primarily enriched in cell fluid.At the jointing and heading stages,the Cu concentration in the leaf cell wall was significantly higher than that in the cell fluid,and the main enrichment was transferred to the cell wall.During the above three growth stages,no Cu was discovered in leaf organelles.Further studies showed that the total soluble protein content in wheat leaves at the tillering and jointing stages showed a trend of first rising and then falling with increased Cu dosage.At the heading stage,under low and medium Cu stress,the total soluble protein content showed no remarkable change.Malondialdehyde(MDA)content at the tillering stage increased with the increase of Cu concentration in the soil,while MDA content did not change noticeably at the jointing and heading stages.At the tillering and heading stages,the low concentrations of Cu increased peroxidase(POD)activity.The POD activity decreased gradually with the increased Cu concentration.However,at the high concentrations of Cu,there was no significant difference in the activity of POD.At the jointing stage,the POD activity did not change significantly under the low Cu stress while it was evidently inhibited under high Cu stress.Based on the above studies,further analyses on the correlation between canopy spectral characteristics and the Cu accumulation at different growth stages of leaf cells were performed,and a new combined index SIPI/NDVI705 performed well in Cu content prediction.The results showed that at different growth stages,different sensitive spectral characteristic parameters should be used to predict the Cu content in leaf cells.展开更多
Using data on wind stress, significant height of combined wind waves and swell, potential temperature, salinity and seawater velocity, as well as objectively-analyzed in situ temperature and salinity, we established a...Using data on wind stress, significant height of combined wind waves and swell, potential temperature, salinity and seawater velocity, as well as objectively-analyzed in situ temperature and salinity, we established a global ocean dataset of calculated wind- and tide-induced vertical turbulent mixing coefficients. We then examined energy conservation of ocean vertical mixing from the point of view of ocean wind energy inputs, gravitational potential energy change due to mixing(with and without artificially limiting themixing coefficient), and K-theory vertical turbulent parameterization schemes regardless of energy inputs. Our research showed that calculating the mixing coefficient with average data and artificial limiting the mixing coefficient can cause a remarkable lack of energy conservation, with energy losses of up to 90% and changes in the energy oscillation period. The data also show that wind can introduce a huge amount of energy into the upper layers of the Southern Ocean, and that tidesdo so in regions around underwater mountains. We argue that it is necessary to take wind and tidal energy inputs into account forlong-term ocean climate numerical simulations. We believe that using this ocean vertical turbulent mixing coefficient climatic dataset is a fast and efficient method to maintain the ocean energy balance in ocean modeling research.展开更多
Hydrocarbon microseepage can result in related near-surface mineral alterations.In this study,we evaluated the potential of detecting these alterations with field measured and satellite acquired hyperspectral data.Fou...Hydrocarbon microseepage can result in related near-surface mineral alterations.In this study,we evaluated the potential of detecting these alterations with field measured and satellite acquired hyperspectral data.Fourteen soil samples and reflectance spectra were collected in the Xifeng Oilfield,a loess covered area.Soil samples were analyzed in the laboratory for calcite,dolomite,kaolinite,illite,and mixedlayer illite/smectite content,and we processed reflectance spectra for continuum removal to derive clay and carbonate mineral absorption depth(H).High correlation between absorption depth and mineral content was shown for clay and mineral carbonate with field measured spectra.Based on the result for the field spectra,we proposed and tested a fast index based on the absorption depth of clay and carbonate minerals with a hyperspectral image of the area.The detected hydrocarbon microseepage anomalies matched well with those shown in the geological map.展开更多
文摘Using the asymptotic iteration method, we obtain the S-wave solution for a short-range three-parameter central potential with 1/r singularity and with a non-orbital barrier. To the best of our knowledge, this is the first attempt at calculating the energy spectrum for this potential, which was introduced by H. Bahlouli and A. D. Alhaidari and for which they obtained the “potential parameter spectrum”. Our results are also independently verified using a direct method of diagonalizing the Hamiltonian matrix in the J-matrix basis.
基金The Special Fund for Agriscientific Research in the Public Interest under contract No.201303050the Fundamental Research Funds for the Central Universities under contract Nos 201022001 and 201262004
文摘Multispecies ecological models have been used for predicting the effects of fishing activity and evaluating the performance of management strategies. Size-spectrum models are one type of physiologically-structured ecological model that provide a feasible approach to describing fish communities in terms of individual dietary variation and ontogenetic niche shift. Despite the potential of ecological models in improving our understanding of ecosystems, their application is usually limited for data-poor fisheries. As a first step in implementing ecosystem-based fisheries management(EBFM), this study built a size-spectrum model for the fish community in the Haizhou Bay, China. We describe data collection procedures and model parameterization to facilitate the implementation of such size-spectrum models for future studies of data-poor ecosystems. The effects of fishing on the ecosystem were exemplified with a range of fishing effort and were monitored with a set of ecological indicators. Total community biomass, biodiversity index, W-statistic, LFI(Large fish index), Mean W(mean body weight) and Slope(slope of community size spectra) showed a strong non-linear pattern in response to fishing pressure, and largest fishing effort did not generate the most drastic responses in certain scenarios. We emphasize the value and feasibility of developing size-spectrum models to capture ecological dynamics and suggest limitations as well as potential for model improvement. This study aims to promote a wide use of this type of model in support of EBFM.
基金Supported by National Natural Science Foundation of China (Grant Nos. 40731055 and 40774085)the Innovative Research Team Project, Ministry of Education, the Knowledge Innovation Program of the Chinese Academy of Sciences (IAP07315)+1 种基金the China Meteorological Administration (Grant No. GYHY200706013)the Open Programs of Key Laboratory of Geospace Environment and Geodesy, Ministry of Education
文摘On the basis of previous parameterization schemes, considering both the wave breaking and absorbed at critical level, a parameterization with a continuous spectrum of gravity waves is realized by introducing a momentum flux density function for the wave spectrum, and then the parameterization scheme of the gravity waves is improved. Choosing parameter values of the background atmosphere and waves based on the observations, a more realistic equatorial quasi-biennial oscillation (QBO) driven by the incorporated drag from the planetary and gravity waves can be simulated. The numerical results indicate that the forcing magnitude of the planetary and gravity waves varies with the wind field, and in some phases of the QBO, the contribution of the gravity waves is comparable with that of the planetary waves. After the QBO is steadily formed, its amplitude and period and wind configuration are relevant to the effect of vertical diffusion and the momentum flux distribution with spectrum, however, independent of the initial background wind field. Moreover, for any given nonzero initial background wind, a steady QBO can be finally generated due to the incorporated drag from the planetary and gravity waves.
基金This work was supported by the National Natural Science Fund of China(41471279)。
文摘To study the mechanism of Cu toxicity on wheat,the characteristics of Cu stress in pivotal growth periods of wheat were explored by field planting methods.The results showed that at the tillering stage,the concentrations of Cu in the leaf cell fluid were significantly higher than those in the cell wall,and the Cu was primarily enriched in cell fluid.At the jointing and heading stages,the Cu concentration in the leaf cell wall was significantly higher than that in the cell fluid,and the main enrichment was transferred to the cell wall.During the above three growth stages,no Cu was discovered in leaf organelles.Further studies showed that the total soluble protein content in wheat leaves at the tillering and jointing stages showed a trend of first rising and then falling with increased Cu dosage.At the heading stage,under low and medium Cu stress,the total soluble protein content showed no remarkable change.Malondialdehyde(MDA)content at the tillering stage increased with the increase of Cu concentration in the soil,while MDA content did not change noticeably at the jointing and heading stages.At the tillering and heading stages,the low concentrations of Cu increased peroxidase(POD)activity.The POD activity decreased gradually with the increased Cu concentration.However,at the high concentrations of Cu,there was no significant difference in the activity of POD.At the jointing stage,the POD activity did not change significantly under the low Cu stress while it was evidently inhibited under high Cu stress.Based on the above studies,further analyses on the correlation between canopy spectral characteristics and the Cu accumulation at different growth stages of leaf cells were performed,and a new combined index SIPI/NDVI705 performed well in Cu content prediction.The results showed that at different growth stages,different sensitive spectral characteristic parameters should be used to predict the Cu content in leaf cells.
基金supported by National Natural Science Foundation of China(Grant No.41175058)
文摘Using data on wind stress, significant height of combined wind waves and swell, potential temperature, salinity and seawater velocity, as well as objectively-analyzed in situ temperature and salinity, we established a global ocean dataset of calculated wind- and tide-induced vertical turbulent mixing coefficients. We then examined energy conservation of ocean vertical mixing from the point of view of ocean wind energy inputs, gravitational potential energy change due to mixing(with and without artificially limiting themixing coefficient), and K-theory vertical turbulent parameterization schemes regardless of energy inputs. Our research showed that calculating the mixing coefficient with average data and artificial limiting the mixing coefficient can cause a remarkable lack of energy conservation, with energy losses of up to 90% and changes in the energy oscillation period. The data also show that wind can introduce a huge amount of energy into the upper layers of the Southern Ocean, and that tidesdo so in regions around underwater mountains. We argue that it is necessary to take wind and tidal energy inputs into account forlong-term ocean climate numerical simulations. We believe that using this ocean vertical turbulent mixing coefficient climatic dataset is a fast and efficient method to maintain the ocean energy balance in ocean modeling research.
基金supported by the National Natural Science Foundation of China(No.41402293)the GF-5 Satellite Hyperspectral Porphyry Deposit Alteration Information Intelligent Identification Technology Program(No.04-Y20A35-9001-15/17-4)
文摘Hydrocarbon microseepage can result in related near-surface mineral alterations.In this study,we evaluated the potential of detecting these alterations with field measured and satellite acquired hyperspectral data.Fourteen soil samples and reflectance spectra were collected in the Xifeng Oilfield,a loess covered area.Soil samples were analyzed in the laboratory for calcite,dolomite,kaolinite,illite,and mixedlayer illite/smectite content,and we processed reflectance spectra for continuum removal to derive clay and carbonate mineral absorption depth(H).High correlation between absorption depth and mineral content was shown for clay and mineral carbonate with field measured spectra.Based on the result for the field spectra,we proposed and tested a fast index based on the absorption depth of clay and carbonate minerals with a hyperspectral image of the area.The detected hydrocarbon microseepage anomalies matched well with those shown in the geological map.