Weijia Guyot,located in the western Pacific Ocean,has become a research focus due to its abundant cobalt-rich ferromanganese(Fe-Mn)crusts.While most studies on Fe-Mn crusts on seamounts have focused on the exposed var...Weijia Guyot,located in the western Pacific Ocean,has become a research focus due to its abundant cobalt-rich ferromanganese(Fe-Mn)crusts.While most studies on Fe-Mn crusts on seamounts have focused on the exposed variety,less attention has been paid to potential buried crusts.This study presents a preliminary geochemical and chronological study of buried Fe-Mn crusts at Weijia Guyot.The findings suggest that these buried crusts began to form around 57.5 Ma and ceased growing at approximately 46.3 Ma.Following the formation of Weijia Guyot through volcanic eruption,it did not experience continuous and steady subsidence to its current depth.Instead,an exhumation process took place from deep to shallow depths between 46.3 and 11.6 Ma.This process brought the Fe-Mn crusts into shallow water environments,halting their growth.During this time,Weijia Guyot was located near the equatorial Pacific Ocean and was exposed to an extended period of phosphatization.This exposure led to a depletion of key metallogenic elements,such as Co,Ni and Cu,within the Fe-Mn crusts,while P2O5 and CaO levels increased significantly.Since the Middle Miocene,the crusts have been progressively buried by pelagic sediments.展开更多
In 2001, the International Seabed Authority （ISBA） initiated the consideration relating to the Regulations for Prospecting and Exploration for Hydrothermal Polymetallic Sulphides and Cobalt-rich Ferromanganese Crust...In 2001, the International Seabed Authority （ISBA） initiated the consideration relating to the Regulations for Prospecting and Exploration for Hydrothermal Polymetallic Sulphides and Cobalt-rich Ferromanganese Crusts in the Area at its 7th session. Since then, the consideration of the Regulations has been mainly focused on the size of areas to be allocated for exploration and exploitation of the crusts. This paper, based on the investigation data and the analysis of the distribution characteristics of the crusts, suggests a model for determining the size of areas for exploration and exploitation of the crusts, taking into account various factors such as production scale, crust thickness and grade, mineable area proportion, recovery efficiency, exploration venture, and so on. Through the modeling, the paper suggests that the exploration area （the area covered by each application for approval of a plan of work for exploration of cobalt-rich crusts） shall be 4 856 km2 and the exploitation area （the mine site area） shall be 1 214 km2, for 20 years of 1 million wet tonnes annual production.展开更多
Using the SeaBeam technology, the morphology of seamount and its relation to the formation of cobalt-rich crust in the central Pacific Ocean were surveyed during the cruise in 2003 for marine mineral resources. The re...Using the SeaBeam technology, the morphology of seamount and its relation to the formation of cobalt-rich crust in the central Pacific Ocean were surveyed during the cruise in 2003 for marine mineral resources. The result shows that seamounts can be divided morphologically into the spire seamount and the fiat topped seamount. These two types of seamount bear great differences in their landform, lithology and cobalt-rich crust. On the upper portion of the fiat topped seamount, the fiat top and the sharp escarpments are unfavorable to the growth of crust, and, consequently, the crusts here are mostly laminar or gravelly, their thicknesses generally show great variations, and the consecutive ore body often develops in its deep water region. On the spire topped seamount, however, the fiat area is small, and its gradient is constant without large variation from the top to the bottom. This favors the growth of cobalt-rich crust and often leads to consecutive tabular ore body of medium thickness, occurring on the spire topped seamount from the shallow water region to the deep water region. The cobalt-rich crust on the spire topped seamount is much better than that on the fiat topped seamount for the crust abundance, crust coverage and number of ore-occurrences within unit area. Furthermore, the crust on the spire topped seamount is rich in cobalt, nickel, manganese elements of high economic value. Because the crust with high quality ore often occurs in the shallow water region on the spire topped seamount, it can be mined and use more easily in the future.展开更多
新型冠状病毒肺炎疫情引起了人们对国家公共卫生事件应对能力的广泛关注。基于波及效应梯度场提出了生产诱发梯度,进一步完善了经济空间场理论,并将其与探索性空间数据分析(exploratory spatial data analysis,ESDA)相结合,对医药制造...新型冠状病毒肺炎疫情引起了人们对国家公共卫生事件应对能力的广泛关注。基于波及效应梯度场提出了生产诱发梯度,进一步完善了经济空间场理论,并将其与探索性空间数据分析(exploratory spatial data analysis,ESDA)相结合,对医药制造业波及效应及空间布局进行了研究,制定了有效的公共卫生事件应急策略。经济空间场理论分析结果揭示了产业经济空间中医药制造业与各产业部门之间的波及效应,并由此得到了医药密切相关产业。同时,经济空间场理论与ESDA方法的结合能在区分中国大陆各省空间聚集类型的基础上,评估各省公共卫生事件的应对能力,从而为各省提出相应的应急策略和医药制造业发展建议。该方法综合考虑了产业波及效应和产业空间布局现状,不仅能够促进各省医药制造业的健康合理发展,也有助于增强各省突发公共卫生事件的应对能力。展开更多
In order to study buckling propagation mechanism in deep sea pipelines, the contact between pipeline's inner walls in buckling process was studied. A two-dimensional ring model was used to represent the pipeline a...In order to study buckling propagation mechanism in deep sea pipelines, the contact between pipeline's inner walls in buckling process was studied. A two-dimensional ring model was used to represent the pipeline and a nonlinear spring model was adopted to simulate the contact between inner walls. Based on the elastoplastic constitutive relationship and the principle of virtual work theory, the coupling effect of pipeline's nonlinear large deformation and wall contact was included in the theoretical analysis with the aid of MATLAB, and the application scope of the theoretical model was also discussed. The calculated results show that during the loading process, the change in external pressure is closely related to the distribution of section stress, and once the walls are contacting each other, the external pressure increases and then remains stable after it reaches a specific value. Without fracture, the pipeline section will stop showing deformation. The results of theoretical calculations agree well with those of numerical simulations. Finally, in order to ensure reliability and accuracy of the theoretical results, the collapse pressure and propagation pressure were both verified by numerical simulations and experiments. Therefore, the theoretical model can be used to analyze pipeline's buckling deformation and contact between pipeline's inner walls, which forms the basis for further research on three-dimensional buckling propagation.展开更多
On the basis of three geological models and several orebody boundaries, a method of grid subdivision and integral has been proposed to calculate and evaluate the resources of cobalt-rich crusts on the seamounts in the...On the basis of three geological models and several orebody boundaries, a method of grid subdivision and integral has been proposed to calculate and evaluate the resources of cobalt-rich crusts on the seamounts in the central Pacific Ocean. The formulas of this method are deduced and the interface of program module is designed. The method is carried out in the software ＂Auto mapping system of submarine topography and geomorphology MBChart＂. This method and program will possibly become a potential tool to calculate the resources of seamounts and determine the target diggings for China＇ s next Five-year Plan.展开更多
In order to theoretically study the buckle propagation of subsea pipelines with slip-on buckle arrestors, a two-dimensional ring model was set up to represent the pipeline and a nonlinear spring model was adopted to s...In order to theoretically study the buckle propagation of subsea pipelines with slip-on buckle arrestors, a two-dimensional ring model was set up to represent the pipeline and a nonlinear spring model was adopted to simulate the contact between pipeline's inner walls and between pipeline's outer wall and slip-on buckle arrestor's inner wall during buckle propagation. In addition, some reverse springs are added to prevent the wall of left and right sides separating from the inner wall of slip-on buckle arrestors. Considering large deformation kinematics relations and the elastic-plastic constitutive relation of material, balance equations were established with the principle of virtual work. The variation of external pressure with respect to the cross-sectional area of pipelines was analyzed, and the lower bound of the crossover pressure of slip-on buckle arrestors was calculated based on Maxwell's energy balance method. By comparing the theoretical results with experiment and finite element numerical simulation, the theoretical method is proved to be correct and reliable.展开更多
基金financial support from the National Natural Science Foundation of China(Grant No.U2244222,42576244,42072324,42442603)the Guangzhou Basic and Applied Basic Research Foundation(Grant No.202201011367,202201011487).
文摘Weijia Guyot,located in the western Pacific Ocean,has become a research focus due to its abundant cobalt-rich ferromanganese(Fe-Mn)crusts.While most studies on Fe-Mn crusts on seamounts have focused on the exposed variety,less attention has been paid to potential buried crusts.This study presents a preliminary geochemical and chronological study of buried Fe-Mn crusts at Weijia Guyot.The findings suggest that these buried crusts began to form around 57.5 Ma and ceased growing at approximately 46.3 Ma.Following the formation of Weijia Guyot through volcanic eruption,it did not experience continuous and steady subsidence to its current depth.Instead,an exhumation process took place from deep to shallow depths between 46.3 and 11.6 Ma.This process brought the Fe-Mn crusts into shallow water environments,halting their growth.During this time,Weijia Guyot was located near the equatorial Pacific Ocean and was exposed to an extended period of phosphatization.This exposure led to a depletion of key metallogenic elements,such as Co,Ni and Cu,within the Fe-Mn crusts,while P2O5 and CaO levels increased significantly.Since the Middle Miocene,the crusts have been progressively buried by pelagic sediments.
基金China International Seabed Area R & D Program under contract No.DYXM-115-01-1
文摘In 2001, the International Seabed Authority （ISBA） initiated the consideration relating to the Regulations for Prospecting and Exploration for Hydrothermal Polymetallic Sulphides and Cobalt-rich Ferromanganese Crusts in the Area at its 7th session. Since then, the consideration of the Regulations has been mainly focused on the size of areas to be allocated for exploration and exploitation of the crusts. This paper, based on the investigation data and the analysis of the distribution characteristics of the crusts, suggests a model for determining the size of areas for exploration and exploitation of the crusts, taking into account various factors such as production scale, crust thickness and grade, mineable area proportion, recovery efficiency, exploration venture, and so on. Through the modeling, the paper suggests that the exploration area （the area covered by each application for approval of a plan of work for exploration of cobalt-rich crusts） shall be 4 856 km2 and the exploitation area （the mine site area） shall be 1 214 km2, for 20 years of 1 million wet tonnes annual production.
文摘Using the SeaBeam technology, the morphology of seamount and its relation to the formation of cobalt-rich crust in the central Pacific Ocean were surveyed during the cruise in 2003 for marine mineral resources. The result shows that seamounts can be divided morphologically into the spire seamount and the fiat topped seamount. These two types of seamount bear great differences in their landform, lithology and cobalt-rich crust. On the upper portion of the fiat topped seamount, the fiat top and the sharp escarpments are unfavorable to the growth of crust, and, consequently, the crusts here are mostly laminar or gravelly, their thicknesses generally show great variations, and the consecutive ore body often develops in its deep water region. On the spire topped seamount, however, the fiat area is small, and its gradient is constant without large variation from the top to the bottom. This favors the growth of cobalt-rich crust and often leads to consecutive tabular ore body of medium thickness, occurring on the spire topped seamount from the shallow water region to the deep water region. The cobalt-rich crust on the spire topped seamount is much better than that on the fiat topped seamount for the crust abundance, crust coverage and number of ore-occurrences within unit area. Furthermore, the crust on the spire topped seamount is rich in cobalt, nickel, manganese elements of high economic value. Because the crust with high quality ore often occurs in the shallow water region on the spire topped seamount, it can be mined and use more easily in the future.
基金中国大洋协会《富钴结壳及多金属硫化物合同区资源勘探与评价项目》(编号:DY135-C1-1-05、DY135-C1-1-03、DY135-S1-1-04)自然资源部海底矿产资源重点实验室基金《嘉偕平顶山群浅埋藏型富钴结壳浅剖资料属性研究》(编号:KLM M R-2018-A-09)国家自然科学基金项目《海底多金属结核和富钴结壳与多波束回波强度的定量关系模型研究》(批准号:41606071)、《西太平洋深海盆地孔隙水稀土元素特征及其对沉积物稀土富集机制初探》(批准号:41803026)
文摘新型冠状病毒肺炎疫情引起了人们对国家公共卫生事件应对能力的广泛关注。基于波及效应梯度场提出了生产诱发梯度,进一步完善了经济空间场理论,并将其与探索性空间数据分析(exploratory spatial data analysis,ESDA)相结合,对医药制造业波及效应及空间布局进行了研究,制定了有效的公共卫生事件应急策略。经济空间场理论分析结果揭示了产业经济空间中医药制造业与各产业部门之间的波及效应,并由此得到了医药密切相关产业。同时,经济空间场理论与ESDA方法的结合能在区分中国大陆各省空间聚集类型的基础上,评估各省公共卫生事件的应对能力,从而为各省提出相应的应急策略和医药制造业发展建议。该方法综合考虑了产业波及效应和产业空间布局现状,不仅能够促进各省医药制造业的健康合理发展,也有助于增强各省突发公共卫生事件的应对能力。
基金supported by the National Natural Science Foundation of China (Grant Nos. 51239008 and 51179126)the National Science and Technology Major Project of the Ministry of Science and Technology of China (Grant No. 2011ZX05026-005)
文摘In order to study buckling propagation mechanism in deep sea pipelines, the contact between pipeline's inner walls in buckling process was studied. A two-dimensional ring model was used to represent the pipeline and a nonlinear spring model was adopted to simulate the contact between inner walls. Based on the elastoplastic constitutive relationship and the principle of virtual work theory, the coupling effect of pipeline's nonlinear large deformation and wall contact was included in the theoretical analysis with the aid of MATLAB, and the application scope of the theoretical model was also discussed. The calculated results show that during the loading process, the change in external pressure is closely related to the distribution of section stress, and once the walls are contacting each other, the external pressure increases and then remains stable after it reaches a specific value. Without fracture, the pipeline section will stop showing deformation. The results of theoretical calculations agree well with those of numerical simulations. Finally, in order to ensure reliability and accuracy of the theoretical results, the collapse pressure and propagation pressure were both verified by numerical simulations and experiments. Therefore, the theoretical model can be used to analyze pipeline's buckling deformation and contact between pipeline's inner walls, which forms the basis for further research on three-dimensional buckling propagation.
基金This study was supported by Projects under contract Nos DY105 China's 0cean-03-01-01 and DY105-03-01-07the National Natural Science Foundation of China under contract No.40506017the Youth Foundation of Marine High-tech Project of China under contract No.2002AA616010.
文摘On the basis of three geological models and several orebody boundaries, a method of grid subdivision and integral has been proposed to calculate and evaluate the resources of cobalt-rich crusts on the seamounts in the central Pacific Ocean. The formulas of this method are deduced and the interface of program module is designed. The method is carried out in the software ＂Auto mapping system of submarine topography and geomorphology MBChart＂. This method and program will possibly become a potential tool to calculate the resources of seamounts and determine the target diggings for China＇ s next Five-year Plan.
基金supported by the National Natural Science Foundation of China (Grant No. 51609222)the Natural Science Foundation of Shandong Province (Grant No. ZR2016EEB03)+2 种基金the Opening Fund of State Key Laboratory of Coastal and Offshore Engineering (Dalian University of Technology) (Grant No. LP1505)the Opening Fund of State Key Laboratory of Hydraulic Engineering Simulation and Safety (Tianjin University) (Grant No. HESS-1602)the Fundamental Research Funds for the Central Universities (Grant No. 201513039)
文摘In order to theoretically study the buckle propagation of subsea pipelines with slip-on buckle arrestors, a two-dimensional ring model was set up to represent the pipeline and a nonlinear spring model was adopted to simulate the contact between pipeline's inner walls and between pipeline's outer wall and slip-on buckle arrestor's inner wall during buckle propagation. In addition, some reverse springs are added to prevent the wall of left and right sides separating from the inner wall of slip-on buckle arrestors. Considering large deformation kinematics relations and the elastic-plastic constitutive relation of material, balance equations were established with the principle of virtual work. The variation of external pressure with respect to the cross-sectional area of pipelines was analyzed, and the lower bound of the crossover pressure of slip-on buckle arrestors was calculated based on Maxwell's energy balance method. By comparing the theoretical results with experiment and finite element numerical simulation, the theoretical method is proved to be correct and reliable.
