The siltation induced by wind waves in an entrance channel is one of the prime factors influencing the operation efficiency of a port. It is necessary to predict the siltation accurately for dredging and ship operatio...The siltation induced by wind waves in an entrance channel is one of the prime factors influencing the operation efficiency of a port. It is necessary to predict the siltation accurately for dredging and ship operation passing through the entrance of the port. However, it is difficult to apply the traditional method to predicting entrance siltation because of its complex computational procedure and lacking the data of ocean dynamic elements in the specified sea area. From the view of energy conservation, a direct relationship between wind conditions and sediment deposition can be founded. On the basis of the above methodology, an empirical formula expressed by wind conditions for forecasting the siltation in the entrance channel is set up. The wind conditions are easily obtained from the local meteorological stations or weather maps, so the formula established in this paper is more convenient and practical than the traditional method. A case study is provided, in which the emopirical formula is calibrated and verified utilizing the measured wind and siltation conditions in the entrance channel of the port. Comparisons between computed values and measured data show satisfactory aqreement.展开更多
Within the framework of the dinuclear system （DNS） model, the fusion reactions leading to the compound nuclei 274Hs＊ and 2S6Cn＊ are investigated. The fusion probability as a function of DNS excitation energy is st...Within the framework of the dinuclear system （DNS） model, the fusion reactions leading to the compound nuclei 274Hs＊ and 2S6Cn＊ are investigated. The fusion probability as a function of DNS excitation energy is studied. The calculated results are in good agreement with the available experimental data. The obtained results show that the fusion probabilities are obviously enhanced for the reactions located at high place in potential energy surface, although these reactions may have small values of mass asymmetry. It is found that the enhancement is due to the large potential energy of the initial DNS.展开更多
In this study,we investigated the entrance channel effect on the evaporation residue cross section of a superheavy element^(296)119.Using 29 projectile-target combinations,we investigated the role of the entrance chan...In this study,we investigated the entrance channel effect on the evaporation residue cross section of a superheavy element^(296)119.Using 29 projectile-target combinations,we investigated the role of the entrance channel on the 3n and 4n evaporation channels in hot combinations.This effect can be evaluated based on the entrance channel asymmetry and Q value of complete fusion.We calculated the variation of the maximum evaporation residue cross sections(σ^(max)_(3n)andσ^(max)_(4n))with|Q|for the reactions^(49-47)Ti+^(247-249)Bk,^(60-57)Fe+^(236-239)Np,^(44-42)Ca+^(252-254)Es,and^(55,54,52)Mn+^(241,242,244)Pu.With an increase in|Q|,σ^(max)_(3n)andσ^(max)_(4n) increase.In addition,we studied the role of asymmetry and mean fissility parameters in the synthesis of the superheavy element.The obtained results in this study can be utilized in future studies.展开更多
The pre-scission neutrons measured in the reactions ^16O＋^181Ta and ^19F＋^178Hf are studied via a Langevin equation coupled with a statistical decay model. We find that because of the mass asymmetry of different ent...The pre-scission neutrons measured in the reactions ^16O＋^181Ta and ^19F＋^178Hf are studied via a Langevin equation coupled with a statistical decay model. We find that because of the mass asymmetry of different entrance channels, the spin distributions of compound nuclei would be different, consequently, the measured neutrons in these two reactions would also different. This means that the entrance channel will affect the particle emission in the fission process of hot nuclei.展开更多
基金Supported by National Natural Science Foundation of China(No.50779045).
文摘The siltation induced by wind waves in an entrance channel is one of the prime factors influencing the operation efficiency of a port. It is necessary to predict the siltation accurately for dredging and ship operation passing through the entrance of the port. However, it is difficult to apply the traditional method to predicting entrance siltation because of its complex computational procedure and lacking the data of ocean dynamic elements in the specified sea area. From the view of energy conservation, a direct relationship between wind conditions and sediment deposition can be founded. On the basis of the above methodology, an empirical formula expressed by wind conditions for forecasting the siltation in the entrance channel is set up. The wind conditions are easily obtained from the local meteorological stations or weather maps, so the formula established in this paper is more convenient and practical than the traditional method. A case study is provided, in which the emopirical formula is calibrated and verified utilizing the measured wind and siltation conditions in the entrance channel of the port. Comparisons between computed values and measured data show satisfactory aqreement.
基金Supported by Natural Science Foundation of Guangdong Province China(2016A030310208)National Natural Science Foundation of China(11605296,11405278,11505150,11635003)+1 种基金Fundamental Research Funds for the Central Universities(15 lgpy 30)China Postdoctoral Science Foundation(2015M582730)
文摘Within the framework of the dinuclear system （DNS） model, the fusion reactions leading to the compound nuclei 274Hs＊ and 2S6Cn＊ are investigated. The fusion probability as a function of DNS excitation energy is studied. The calculated results are in good agreement with the available experimental data. The obtained results show that the fusion probabilities are obviously enhanced for the reactions located at high place in potential energy surface, although these reactions may have small values of mass asymmetry. It is found that the enhancement is due to the large potential energy of the initial DNS.
文摘In this study,we investigated the entrance channel effect on the evaporation residue cross section of a superheavy element^(296)119.Using 29 projectile-target combinations,we investigated the role of the entrance channel on the 3n and 4n evaporation channels in hot combinations.This effect can be evaluated based on the entrance channel asymmetry and Q value of complete fusion.We calculated the variation of the maximum evaporation residue cross sections(σ^(max)_(3n)andσ^(max)_(4n))with|Q|for the reactions^(49-47)Ti+^(247-249)Bk,^(60-57)Fe+^(236-239)Np,^(44-42)Ca+^(252-254)Es,and^(55,54,52)Mn+^(241,242,244)Pu.With an increase in|Q|,σ^(max)_(3n)andσ^(max)_(4n) increase.In addition,we studied the role of asymmetry and mean fissility parameters in the synthesis of the superheavy element.The obtained results in this study can be utilized in future studies.
基金National Natural Science Foundation of China (10405007)
文摘The pre-scission neutrons measured in the reactions ^16O＋^181Ta and ^19F＋^178Hf are studied via a Langevin equation coupled with a statistical decay model. We find that because of the mass asymmetry of different entrance channels, the spin distributions of compound nuclei would be different, consequently, the measured neutrons in these two reactions would also different. This means that the entrance channel will affect the particle emission in the fission process of hot nuclei.
