The key parameters of the adhesive layer of a reinforcing patch are of great significance and affect the ability to suppress crack propagation in an Al–Li alloy patch-reinforced structure.This paper proposes a method...The key parameters of the adhesive layer of a reinforcing patch are of great significance and affect the ability to suppress crack propagation in an Al–Li alloy patch-reinforced structure.This paper proposes a method to determine the key parameters of the adhesive layer of adhesively bonded joints in the Al–Li alloy patch-reinforced structure.A zero-thickness cohesive zone model(CZM)was selected to simulate the adhesive layer’s fracture process,and an orthogonal simulation was designed to compare against the test results.A three-dimensional progressive damage model of an Al–Li alloy patch-reinforced structure with single-lap adhesively bonded joints was developed.The simulation’s results closely agree with the test results,demonstrating that this method of determining the key parameters is likely accurate.The results also verify the correctness of the cohesive strength and fracture energy,the two key parameters of the cohesive zone model.The model can accurately predict the strength and fracture process of adhesively bonded joints,and can be used in research to suppress crack propagation in Al–Li alloy patch-reinforced structures.展开更多
Based on the new data of the Quaternary along the coast of Hainan Island, China, this paper puts forward that the Holocene in Hainan Island can be divided into four formations: Wanning formation (Q41), Sanya formation...Based on the new data of the Quaternary along the coast of Hainan Island, China, this paper puts forward that the Holocene in Hainan Island can be divided into four formations: Wanning formation (Q41), Sanya formation (Q42-1), Qiongshan formation (Q42-2) and Ledong formation (Q43). Spore-pollen analysis shows that there are 6 spore-pollen zones existed, reflecting two cycles of climatic fluctuation from warm-dry to hot-humid. The climax of hot-humid period occurred 6,000-5,000 years B.P.. Based on the 14C dating data of the 38 samples representing the positions of ancient sea level, a breakthrough curve representing the sea level change during the Holocone is obtained, in which , a sea level change caused by tectonic movement is subtracted. Two cycles of rise-drop of sea level with three periods of high sea level were found. The period with the highest sea level is some 6,000-5,000 years B.P.. According to the rise-drop rate of sea level, four periods of the sea level change can be distinguished in展开更多
Ophiolites along the indus Suture Zone (ISZ) are important not only for the information they provide about the India\|Eurasia collision,but may also contain economic mineral deposits (chrome,noble metals,and Ni\|sulfi...Ophiolites along the indus Suture Zone (ISZ) are important not only for the information they provide about the India\|Eurasia collision,but may also contain economic mineral deposits (chrome,noble metals,and Ni\|sulfides).Several ophiolites occur in the ISZ,and the Nidar ophiolite is one that occurs on the eastern Ladakh.This paper presents the geochemistry of ultramafic rocks from the Nidar ophiolite to understand tectonic environment and economic potential.Nidar ophiolite consists of pillow lavas,radiolarian cherts,rodingites,peridotites and chromitites.The lower part of the ophiolite consists of tectonized harzburgite,hosting dunite enveloped podiform chromitites.The transition zone between upper mantle and lower oceanic crust is characterized by serpentinized dunite with disseminations of chromites.Peridotites in Nidar have low whole\|rock values of w (TiO\-2)(0 02%～0 03%), w (Al\-2O\-3)(2%～3%), w (CaO)(0.5%), w (Zr)(40×10 -6 ),and w (Y)(30×10 -6 ),and enriched in refractory elements such as w (Cr)((3000～5000)×10 -6 )and w (Ni)((3000～4000)×10 -6 ).Thus,the Nidar peridotites are more depleted in elements partitioned into the liquid,such as Al and Ca and the moderately refractory element Ti.The peridotites have fractionated chondrite\|normalized PGE patterns.These geochemical characteristics suggests their formation by high degrees of partial melting in a supra\|subduction zone environment,where melting was enhanced by addition of volatiles.The Cr # of 0.82 in the chromite of the chromitites also suggests a depleted mantle source and a supra\|subduction zone environment for the host rocks.Ophiolites formed in supra\|subduction zone setting are very conducive for many metallic and non\|metallic mineral deposits.展开更多
The in-situ hydraulic fracturing stress measurements have been carried out around the coastal marginal land in Fu- jian Province. And the characteristics of magnitude, direction and distribution of tectonic stress hav...The in-situ hydraulic fracturing stress measurements have been carried out around the coastal marginal land in Fu- jian Province. And the characteristics of magnitude, direction and distribution of tectonic stress have been obtained. Based on the observed stress data, the characteristics and activities of fault zones are analyzed and studied in the paper according to the Coulomb friction criteria. 1 The maximum horizontal principal compressive stress is in the NW-WNW direction from the north to the south along the coastline verge, which is parallel to the strike of the NW-trending fault zone, consistent with the direction of principal compressive stress obtained from geological structure and across-fault deformation data, and different from that reflected by focal mechanism solution by about 20°. 2 The horizontal principal stress increases with depth, the relation among three stresses is SH>Sv>Sh or SH≈Sv>Sh, and the stress state is liable to normal fault and strike-slip fault activities. 3 According to Coulomb friction criteria and taking the friction strength μ as 0.6~1.0 for analysis, the stress state reaching or exceeding the threshold for normal-fault frictional sliding near the fault implies that the current tectonic activity in the measuring area is mainly normal faulting. 4 The force source of current tectonic stress field comes mainly from the westward and northwestward horizontal extrusions from the Pacific and Philippine Plates respectively to the Eurasian Plate.展开更多
Taking Economic Zone on the Western Coast of the Taiwan Straits as the study area,we use GIS,remote sensing,mathematical statistics and other methods,to analyze the forest pattern and its variation characteristics in ...Taking Economic Zone on the Western Coast of the Taiwan Straits as the study area,we use GIS,remote sensing,mathematical statistics and other methods,to analyze the forest pattern and its variation characteristics in Economic Zone on the Western Coast of the Taiwan Straits during the period 1992-2008;use canonical correspondence analysis(CCA)to examine the effects of environmental factors on changes in forest pattern.The results show that the forest resources are rich in Economic Zone on the Western Coast of the Taiwan Straits,accounting for 61.40% of the total area,but the geographical distribution is very uneven,with obvious regional and elevation gradient difference;since1992,the forest has been dwindling in Economic Zone on the Western Coast of the Taiwan Straits,from 89 300 km2 in 1992 to 88 300 km2 in 2008;in terms of changes in region and elevation gradient,there is obvious difference in the forest,and the central and western forest of Wuyi Mountain tends to decline obviously;the main environmental factors influencing changes in forest pattern in Economic Zone on the Western Coast of the Taiwan Straits include temperature,sunshine hours,GDP per capita and precipitation;evaporation,evaporation and population density have weak effects on changes in forest pattern.展开更多
The coupling numerical model between astronomical tide and tsunamis was built based on the data of the COMCOT model, which was verified by the Japan "3·11" tsunami. The tsunami source of the Manila seis...The coupling numerical model between astronomical tide and tsunamis was built based on the data of the COMCOT model, which was verified by the Japan "3·11" tsunami. The tsunami source of the Manila seismic tsunami was designed and computed to analyze the risk of tsunami which will happen in the Guangdong coast. According to the results, the maximum quantity of water increasing and the time of the tsunami arriving at the Guangdong seacoast were calculated. The coupling simulation between astronomical tide and tsunamis has significant meaning for evaluating the risk and early-warning of tsunamis in the Guangdong coastal area.展开更多
On one hand,the diversity of activities and on the other hand,the conflicts between beneficiaries necessitate the efficient management and supervision of coastal areas.Accordingly,monitoring and evaluation of such are...On one hand,the diversity of activities and on the other hand,the conflicts between beneficiaries necessitate the efficient management and supervision of coastal areas.Accordingly,monitoring and evaluation of such areas can be considered as a critical factor in the national development and directorship of the sources.With regard to this fact,remote sourcing technologies with use of analytical operations of geographic information systems(GIS),will be remarkably advantageous.Iran’s south-eastern Makran coasts are geopolitically and economically,of importance due to their strategic characteristics but have been neglected and their development and transit infrastructure are significantly beyond the international standards.Therefore,in this paper,with regard to the importance of developing Makran coasts,a Multi-Criterion Decision Analysis(MCDA)method was applied to identify and prioritize the intended criteria and parameters of zoning,in order to establish new maritime zones.The major scope of this study is to employ the satellite data,remote sensing methods,and regional statistics obtained from Jask synoptic station and investigate the region’s status in terms of topography,rainfall rate and temperature changes to reach to a comprehensive monitoring and zoning of the coastal line and to provide a pervasive local data base via use of GIS and MCDA,which will be implemented to construct the coastal regions.In this article,while explaining the steps of coastal monitoring,its main objectives are also explained and the necessary procedures for doing so are presented.Then,the general steps of marine climate identification and study of marine parameters are stated and the final achievements of the coastal monitoring process are determined.In the following,considering that this article focuses on the monitoring of Makran beaches,the method of work in the mentioned region will be described and its specific differences and complexities will be discussed in detail.Also,the impact of such projects on future research results will be discussed.展开更多
基金Project(51575535)supported by the National Natural Science Foundation of ChinaProject(2015CX002)supported by the Innovation-driven Plan in Central South University,China+2 种基金Project(zzyjkt2013-09B)supported by the Fund of the State Key Laboratory of High Performance Manufacturing,ChinaProject(2017zzts638)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(2016RS2015)supported by the Scientific and Technological Leading Talent Projects of Hunan Province,China
文摘The key parameters of the adhesive layer of a reinforcing patch are of great significance and affect the ability to suppress crack propagation in an Al–Li alloy patch-reinforced structure.This paper proposes a method to determine the key parameters of the adhesive layer of adhesively bonded joints in the Al–Li alloy patch-reinforced structure.A zero-thickness cohesive zone model(CZM)was selected to simulate the adhesive layer’s fracture process,and an orthogonal simulation was designed to compare against the test results.A three-dimensional progressive damage model of an Al–Li alloy patch-reinforced structure with single-lap adhesively bonded joints was developed.The simulation’s results closely agree with the test results,demonstrating that this method of determining the key parameters is likely accurate.The results also verify the correctness of the cohesive strength and fracture energy,the two key parameters of the cohesive zone model.The model can accurately predict the strength and fracture process of adhesively bonded joints,and can be used in research to suppress crack propagation in Al–Li alloy patch-reinforced structures.
文摘Based on the new data of the Quaternary along the coast of Hainan Island, China, this paper puts forward that the Holocene in Hainan Island can be divided into four formations: Wanning formation (Q41), Sanya formation (Q42-1), Qiongshan formation (Q42-2) and Ledong formation (Q43). Spore-pollen analysis shows that there are 6 spore-pollen zones existed, reflecting two cycles of climatic fluctuation from warm-dry to hot-humid. The climax of hot-humid period occurred 6,000-5,000 years B.P.. Based on the 14C dating data of the 38 samples representing the positions of ancient sea level, a breakthrough curve representing the sea level change during the Holocone is obtained, in which , a sea level change caused by tectonic movement is subtracted. Two cycles of rise-drop of sea level with three periods of high sea level were found. The period with the highest sea level is some 6,000-5,000 years B.P.. According to the rise-drop rate of sea level, four periods of the sea level change can be distinguished in
文摘Ophiolites along the indus Suture Zone (ISZ) are important not only for the information they provide about the India\|Eurasia collision,but may also contain economic mineral deposits (chrome,noble metals,and Ni\|sulfides).Several ophiolites occur in the ISZ,and the Nidar ophiolite is one that occurs on the eastern Ladakh.This paper presents the geochemistry of ultramafic rocks from the Nidar ophiolite to understand tectonic environment and economic potential.Nidar ophiolite consists of pillow lavas,radiolarian cherts,rodingites,peridotites and chromitites.The lower part of the ophiolite consists of tectonized harzburgite,hosting dunite enveloped podiform chromitites.The transition zone between upper mantle and lower oceanic crust is characterized by serpentinized dunite with disseminations of chromites.Peridotites in Nidar have low whole\|rock values of w (TiO\-2)(0 02%～0 03%), w (Al\-2O\-3)(2%～3%), w (CaO)(0.5%), w (Zr)(40×10 -6 ),and w (Y)(30×10 -6 ),and enriched in refractory elements such as w (Cr)((3000～5000)×10 -6 )and w (Ni)((3000～4000)×10 -6 ).Thus,the Nidar peridotites are more depleted in elements partitioned into the liquid,such as Al and Ca and the moderately refractory element Ti.The peridotites have fractionated chondrite\|normalized PGE patterns.These geochemical characteristics suggests their formation by high degrees of partial melting in a supra\|subduction zone environment,where melting was enhanced by addition of volatiles.The Cr # of 0.82 in the chromite of the chromitites also suggests a depleted mantle source and a supra\|subduction zone environment for the host rocks.Ophiolites formed in supra\|subduction zone setting are very conducive for many metallic and non\|metallic mineral deposits.
基金National Development and Reform Commission [2004]1138.
文摘The in-situ hydraulic fracturing stress measurements have been carried out around the coastal marginal land in Fu- jian Province. And the characteristics of magnitude, direction and distribution of tectonic stress have been obtained. Based on the observed stress data, the characteristics and activities of fault zones are analyzed and studied in the paper according to the Coulomb friction criteria. 1 The maximum horizontal principal compressive stress is in the NW-WNW direction from the north to the south along the coastline verge, which is parallel to the strike of the NW-trending fault zone, consistent with the direction of principal compressive stress obtained from geological structure and across-fault deformation data, and different from that reflected by focal mechanism solution by about 20°. 2 The horizontal principal stress increases with depth, the relation among three stresses is SH>Sv>Sh or SH≈Sv>Sh, and the stress state is liable to normal fault and strike-slip fault activities. 3 According to Coulomb friction criteria and taking the friction strength μ as 0.6~1.0 for analysis, the stress state reaching or exceeding the threshold for normal-fault frictional sliding near the fault implies that the current tectonic activity in the measuring area is mainly normal faulting. 4 The force source of current tectonic stress field comes mainly from the westward and northwestward horizontal extrusions from the Pacific and Philippine Plates respectively to the Eurasian Plate.
基金Supported by Special Financial Project of the Ministry of Environmental Protection(2110203)
文摘Taking Economic Zone on the Western Coast of the Taiwan Straits as the study area,we use GIS,remote sensing,mathematical statistics and other methods,to analyze the forest pattern and its variation characteristics in Economic Zone on the Western Coast of the Taiwan Straits during the period 1992-2008;use canonical correspondence analysis(CCA)to examine the effects of environmental factors on changes in forest pattern.The results show that the forest resources are rich in Economic Zone on the Western Coast of the Taiwan Straits,accounting for 61.40% of the total area,but the geographical distribution is very uneven,with obvious regional and elevation gradient difference;since1992,the forest has been dwindling in Economic Zone on the Western Coast of the Taiwan Straits,from 89 300 km2 in 1992 to 88 300 km2 in 2008;in terms of changes in region and elevation gradient,there is obvious difference in the forest,and the central and western forest of Wuyi Mountain tends to decline obviously;the main environmental factors influencing changes in forest pattern in Economic Zone on the Western Coast of the Taiwan Straits include temperature,sunshine hours,GDP per capita and precipitation;evaporation,evaporation and population density have weak effects on changes in forest pattern.
基金sponsored by the Youth Fund Project of the National Natural Science Foundation of China(51509023)the Open-end Fund Project of State Key Laboratory of Hydraulic Engineering Simulation and Safety(HESS-1401)+3 种基金Major Open-end Fund Project of Key Laboratory of South China Sea Rights Protection Technology and Application,State Oceanic Administration(SCS1606)Open-end Fund of Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province(2017SS04)Project supported by South China Sea Branch,State Oceanic Administration for Director of Marine Science and Technology(1417)Key Founding of South China Sea Branch of State Oceanic Administration(180106)
文摘The coupling numerical model between astronomical tide and tsunamis was built based on the data of the COMCOT model, which was verified by the Japan "3·11" tsunami. The tsunami source of the Manila seismic tsunami was designed and computed to analyze the risk of tsunami which will happen in the Guangdong coast. According to the results, the maximum quantity of water increasing and the time of the tsunami arriving at the Guangdong seacoast were calculated. The coupling simulation between astronomical tide and tsunamis has significant meaning for evaluating the risk and early-warning of tsunamis in the Guangdong coastal area.
文摘On one hand,the diversity of activities and on the other hand,the conflicts between beneficiaries necessitate the efficient management and supervision of coastal areas.Accordingly,monitoring and evaluation of such areas can be considered as a critical factor in the national development and directorship of the sources.With regard to this fact,remote sourcing technologies with use of analytical operations of geographic information systems(GIS),will be remarkably advantageous.Iran’s south-eastern Makran coasts are geopolitically and economically,of importance due to their strategic characteristics but have been neglected and their development and transit infrastructure are significantly beyond the international standards.Therefore,in this paper,with regard to the importance of developing Makran coasts,a Multi-Criterion Decision Analysis(MCDA)method was applied to identify and prioritize the intended criteria and parameters of zoning,in order to establish new maritime zones.The major scope of this study is to employ the satellite data,remote sensing methods,and regional statistics obtained from Jask synoptic station and investigate the region’s status in terms of topography,rainfall rate and temperature changes to reach to a comprehensive monitoring and zoning of the coastal line and to provide a pervasive local data base via use of GIS and MCDA,which will be implemented to construct the coastal regions.In this article,while explaining the steps of coastal monitoring,its main objectives are also explained and the necessary procedures for doing so are presented.Then,the general steps of marine climate identification and study of marine parameters are stated and the final achievements of the coastal monitoring process are determined.In the following,considering that this article focuses on the monitoring of Makran beaches,the method of work in the mentioned region will be described and its specific differences and complexities will be discussed in detail.Also,the impact of such projects on future research results will be discussed.
