A numerical method is designed to examine the response properties of real sea areas to open ocean forcing. The application of this method to modeling the China's adjacent seas shows that the Bohai Sea has a highest p...A numerical method is designed to examine the response properties of real sea areas to open ocean forcing. The application of this method to modeling the China's adjacent seas shows that the Bohai Sea has a highest peak response frequency (PRF) of 1.52 d^-1; the northern Yellow Sea has a PRF of 1.69 d^-1; the Gyeonggi Bay has a high amplitude gain plateau in the frequency band roughly from 1.7 to 2.7 d^-1; the Yellow Sea (includ- ing the Gyeonggi Bay), the East China Sea shelf and the Taiwan Strait have a common high amplitude gain band with frequencies around 1.76 to 1.78 d^-1 and are shown to be a system that responds to the open ocean forcing in favor of amplifying the waves with frequencies in this band; the Beibu Gulf, the Gulf of Thailand and the South China Sea deep basin have PRFs of 0.91, 1.01 and 0.98 d^-1 respectively. In addition, the East China Sea has a Poincare mode PRF of 3.91 d^-1. The PRFs of the Bohal Sea, the northern Yellow Sea, the Bei- bu Gulf and the South China Sea can be explained by a classical quarter (half for the Bohai Sea) wavelength resonance theory. The results show that further investigations are needed for the response dynamics of the Yellow Sea-East China Sea-Taiwan Strait system, the East China Sea Poincare mode, the Talwan Strait, and the Gulf of Thailand.展开更多
A conventional method of damage modeling by a reduction in stiffness is insufficient to model the complex non-linear damage characteristics of concrete material accurately.In this research,the concrete damage plastici...A conventional method of damage modeling by a reduction in stiffness is insufficient to model the complex non-linear damage characteristics of concrete material accurately.In this research,the concrete damage plasticity constitutive model is used to develop the numerical model of a deck beam on a berthing jetty in the Abaqus finite element package.The model constitutes a solid section of 3D hexahedral brick elements for concrete material embedded with 2D quadrilateral surface elements as reinforcements.The model was validated against experimental results of a beam of comparable dimensions in a cited literature.The validated beam model is then used in a three-point load test configuration to demonstrate its applicability for preliminary numerical evaluation of damage detection strategy in marine concrete structural health monitoring.The natural frequency was identified to detect the presence of damage and mode shape curvature was found sensitive to the location of damage.展开更多
Flooding is the most frequent disaster in China. It affects people's lives and properties, causing considerable economic loss. Flood forecast and operation of reservoirs are important in flood emergency management. A...Flooding is the most frequent disaster in China. It affects people's lives and properties, causing considerable economic loss. Flood forecast and operation of reservoirs are important in flood emergency management. Although great progress has been achieved in flood forecast and reservoir operation through using computer, network technology, and geographic information system technology in China, the prediction accuracy of models are not satisfactory due to the unavailability of real-time monitoring data. Also, real-time flood control scenario analysis is not effective in many regions and can seldom provide online decision support function. In this research, a decision support system for real-time flood forecasting in Yujiang River Basin, South China (DSS-YRB) is introduced in this paper. This system is based on hydrological and hydraulic mathematical models. The conceptual framework and detailed components of the proposed DSS-YRB is illustrated, which employs real-time rainfall data conversion, model-driven hydrologic forecasting, model calibration, data assimilation methods, and reservoir operational scenario analysis. Multi-tiered architecture offers great flexibility, portability, reusability, and relia- bility. The applied case study results show the development and application of a decision support system for realtime flood forecasting and operation is beneficial for flood control.展开更多
Numerical simulation of sediment transport and bed evolution has become an important technique in the sediment research. In this article, a numerical model of suspended sediment transport was proposed, which was estab...Numerical simulation of sediment transport and bed evolution has become an important technique in the sediment research. In this article, a numerical model of suspended sediment transport was proposed, which was established in the vertical σ coordinate for fitting the free surface and bottom. In the research of the sediment transport, the predominant factors were found to be the eddy diffusion, the settling velocity, the bed condition and so on. By the aid of the model in the article, the contribution of the Rouse parameter to the vertical profile of sediment concentration was clarified, which was identical to the theoretical results. In the comparison of the numerical results with laboratory data, the agreement between experimental data and numerical results was reached except for some data. And the possible reasons for the disagreement were discussed.展开更多
This paper considers the copper electrodeposit ion processes in microvias and investigates whether the quality of the electroplating process can be improved by acoustic streaming using megasonic transducers placed int...This paper considers the copper electrodeposit ion processes in microvias and investigates whether the quality of the electroplating process can be improved by acoustic streaming using megasonic transducers placed into a plating cell. The theoretical results show that acoustic streaming does not take place within the micro-via (either through or blind-via' s), however it does help improve cupric ion transport in the area close to the mouth of a via. This replenishment of cupric ions at the mouth of micro-via leads to better quality filling of the micro-via through diffusion compared to basic conditions. Experiments showing the improved quality of the filling of vias are also presented.展开更多
基金The National Natural Science Foundation of China under contract Nos 40676009 and 40606006the Basic Research Project of Qingdao Science and Technology Program of China under contract No.11-1-4-98-jch
文摘A numerical method is designed to examine the response properties of real sea areas to open ocean forcing. The application of this method to modeling the China's adjacent seas shows that the Bohai Sea has a highest peak response frequency (PRF) of 1.52 d^-1; the northern Yellow Sea has a PRF of 1.69 d^-1; the Gyeonggi Bay has a high amplitude gain plateau in the frequency band roughly from 1.7 to 2.7 d^-1; the Yellow Sea (includ- ing the Gyeonggi Bay), the East China Sea shelf and the Taiwan Strait have a common high amplitude gain band with frequencies around 1.76 to 1.78 d^-1 and are shown to be a system that responds to the open ocean forcing in favor of amplifying the waves with frequencies in this band; the Beibu Gulf, the Gulf of Thailand and the South China Sea deep basin have PRFs of 0.91, 1.01 and 0.98 d^-1 respectively. In addition, the East China Sea has a Poincare mode PRF of 3.91 d^-1. The PRFs of the Bohal Sea, the northern Yellow Sea, the Bei- bu Gulf and the South China Sea can be explained by a classical quarter (half for the Bohai Sea) wavelength resonance theory. The results show that further investigations are needed for the response dynamics of the Yellow Sea-East China Sea-Taiwan Strait system, the East China Sea Poincare mode, the Talwan Strait, and the Gulf of Thailand.
文摘A conventional method of damage modeling by a reduction in stiffness is insufficient to model the complex non-linear damage characteristics of concrete material accurately.In this research,the concrete damage plasticity constitutive model is used to develop the numerical model of a deck beam on a berthing jetty in the Abaqus finite element package.The model constitutes a solid section of 3D hexahedral brick elements for concrete material embedded with 2D quadrilateral surface elements as reinforcements.The model was validated against experimental results of a beam of comparable dimensions in a cited literature.The validated beam model is then used in a three-point load test configuration to demonstrate its applicability for preliminary numerical evaluation of damage detection strategy in marine concrete structural health monitoring.The natural frequency was identified to detect the presence of damage and mode shape curvature was found sensitive to the location of damage.
基金Acknowledgements This research was supported by the special fund of State Key Lab of Water Environment Simulation (11Z01ESPCN), and the Science Foundation of China University of Petroleum, Beijing (JCXK-2011- 05 and KYJJ2012-01-33). Also, the authors would like to extend special appreciation to the anonymous reviewers and the editor for their constructive comments and suggestions that are extremely helpful in improving this paper.
文摘Flooding is the most frequent disaster in China. It affects people's lives and properties, causing considerable economic loss. Flood forecast and operation of reservoirs are important in flood emergency management. Although great progress has been achieved in flood forecast and reservoir operation through using computer, network technology, and geographic information system technology in China, the prediction accuracy of models are not satisfactory due to the unavailability of real-time monitoring data. Also, real-time flood control scenario analysis is not effective in many regions and can seldom provide online decision support function. In this research, a decision support system for real-time flood forecasting in Yujiang River Basin, South China (DSS-YRB) is introduced in this paper. This system is based on hydrological and hydraulic mathematical models. The conceptual framework and detailed components of the proposed DSS-YRB is illustrated, which employs real-time rainfall data conversion, model-driven hydrologic forecasting, model calibration, data assimilation methods, and reservoir operational scenario analysis. Multi-tiered architecture offers great flexibility, portability, reusability, and relia- bility. The applied case study results show the development and application of a decision support system for realtime flood forecasting and operation is beneficial for flood control.
文摘Numerical simulation of sediment transport and bed evolution has become an important technique in the sediment research. In this article, a numerical model of suspended sediment transport was proposed, which was established in the vertical σ coordinate for fitting the free surface and bottom. In the research of the sediment transport, the predominant factors were found to be the eddy diffusion, the settling velocity, the bed condition and so on. By the aid of the model in the article, the contribution of the Rouse parameter to the vertical profile of sediment concentration was clarified, which was identical to the theoretical results. In the comparison of the numerical results with laboratory data, the agreement between experimental data and numerical results was reached except for some data. And the possible reasons for the disagreement were discussed.
基金the Engineering and Physical Sciences Research Council(EPSRC)for their financial support through the grant ASPECT supported by the Scottish Manufacturing Institute(SMI)at Heriot-Watt University
文摘This paper considers the copper electrodeposit ion processes in microvias and investigates whether the quality of the electroplating process can be improved by acoustic streaming using megasonic transducers placed into a plating cell. The theoretical results show that acoustic streaming does not take place within the micro-via (either through or blind-via' s), however it does help improve cupric ion transport in the area close to the mouth of a via. This replenishment of cupric ions at the mouth of micro-via leads to better quality filling of the micro-via through diffusion compared to basic conditions. Experiments showing the improved quality of the filling of vias are also presented.