The thermal structure of the continental subduction zone can be deduced from high-pressure and ultra-high-pressure rock samples or numerical simulation.However,petrological data indicate that the temperature of subduc...The thermal structure of the continental subduction zone can be deduced from high-pressure and ultra-high-pressure rock samples or numerical simulation.However,petrological data indicate that the temperature of subducted continental plates is generally higher than that derived from numerical simulation.In this paper,a two-dimensional kinematic model is used to study the thermal structure of continental subduction zones,with or without a preceding oceanic slab.The results show that the removal of the preceding oceanic slab can effectively increase the slab surface temperature of the continental subduction zone in the early stage of subduction.This can sufficiently explain the difference between the cold thermal structure obtained from previous modeling results and the hot thermal structure obtained from rock sample data.展开更多
The sensitive area of targeted observations for short-term(7 d)prediction of vertical thermal structure(VTS)in summer in the Yellow Sea was investigated.We applied the Conditional Nonlinear Optimal Perturbation(CNOP)m...The sensitive area of targeted observations for short-term(7 d)prediction of vertical thermal structure(VTS)in summer in the Yellow Sea was investigated.We applied the Conditional Nonlinear Optimal Perturbation(CNOP)method and an adjoint-free algorithm with the Regional Ocean Modeling System(ROMS).We used vertical integration of CNOP-type temperature errors to locate the sensitive areas,where reduction of initial errors is expected to yield the greatest improvement in VTS prediction for the selected verification area.The identified sensitive areas were northeast−southwest orientated northeast to the verification area,which were possibly related to the southwestward background currents.Then,we performed a series of sensitivity experiments to evaluate the effectiveness of the identified sensitive areas.Results show that initial errors in the identified sensitive areas had the greatest negative effect on VTS prediction in the verification area compared to errors in other areas(e.g.,the verification area and areas to its east and northeast).Moreover,removal of initial errors through deploying simulated observations in the identified sensitive areas led to more refined prediction than correction of initial conditions in the verification area itself.Our results suggest that implementation of targeted observation in the CNOP-based sensitive areas is an effective method to improve short-term prediction of VTS in summer in the Yellow Sea.展开更多
Guangdong Province in Southeast China is noted for its numerous geothermal resources due to tectonic episodes,mainly occurred during the Cretaceous.The surface heat flow and geothermal gradient are the most direct way...Guangdong Province in Southeast China is noted for its numerous geothermal resources due to tectonic episodes,mainly occurred during the Cretaceous.The surface heat flow and geothermal gradient are the most direct ways to understand the temperature of the Earth.However,geothermal resources are poorly utilized in Guangdong Province due to limited numbers of boreholes and surficial hydrothermal fluids.To improve the understanding of underground temperature distribution in Guangdong Province,we have applied power-density spectral analysis to aeromagnetic anomaly data to calculate the depth of the Curie isothermal surface.Upward continuation is applied and tested to the magnetic data.The calculated Curie isotherm is between 18.5 km and 25 km below surface.The fluctuation in the depth range reflects lateral thermal perturbations in the Guangdong crust.In particular,the eastern,northern,western and coastline areas of the province have a relatively shallow Curie isotherm.By comparing the surface heat flow,geothermal gradient,distribution of Mesozoic granite-volcanic rocks,and natural hot springs,we conclude that during Mesozoic,magmatism exerted great influence on the deep thermal state of Guangdong Province.A shallow Curie isotherm surface,as well as numerous natural hot springs and high heat flow,show clear signatures of shallow heat sources.展开更多
The Bohai Bay Basin is a region where part of the North China Craton has been thinned and destroyed. It has experienced two periods of crustal thinning that occurred during the Cretaceous and Paleogene, but investigat...The Bohai Bay Basin is a region where part of the North China Craton has been thinned and destroyed. It has experienced two periods of crustal thinning that occurred during the Cretaceous and Paleogene, but investigations of its Mesozoic and Cenozoic lithospheric thermal structure are limited. Therefore, in this study,the distributions of mantle heat flow, crustal heat flow, and Moho temperatures during the Meso-Cenozoic are calculated based on analyses of the thermal history of the Bohai Bay Basin. The results indicate that the ratio of mantle heat flow to surface heat flow peaked during the late stages of the early Cretaceous and during the middle to late Paleogene. The corresponding mantle heat flow was more than 65% of the surface heat flow. Moho temperatures reached three peaks: 900-1100℃ in the late stages of the early Cretaceous;820-900℃ in the middle to late Paleogene; and(in the Linqing Depression, Cangxian Uplift, and Jizhong Depression) 770-810℃ during the early Neogene. These results reveal that the Bohai Bay Basin experienced significant geological change during the Cretaceous, including the transformation of lithospheric thermal structure from "cold mantle and hot crust" before the Cretaceous to "hot mantle and cold crust" after the Cretaceous. The results also indicate that the basin experienced two large-scale rifting events.Therefore, this work may provide the thermal parameters for further investigations of the geodynamic evolution of eastern China.展开更多
The Qaidam Basin is a petroleum province in Northeastern Qinghai—Tibetan plateau, China. The Basin is bounded by the Aljin Mountains to the Northwest, the Qilian Mountains to the Northeast, the Qimantager Mountains t...The Qaidam Basin is a petroleum province in Northeastern Qinghai—Tibetan plateau, China. The Basin is bounded by the Aljin Mountains to the Northwest, the Qilian Mountains to the Northeast, the Qimantager Mountains to the Southeast and East Kunlun Mountains to the Southwest. The average elevation of the basin and these mountains are 2700m and 3000～ 5000 m respect to the sea level, respectively. The basin was developed on the pre\|Mesozoic basement. Thickness of Tertiary system is more than 10000m in the basin,but Quaternary is mainly in the eastern basin with thickness more than 3000m. The lithology in Mesozoic and Cenozoic of the basin are mainly sandstone, shale, calcic rocks and the interlayers of sandstone and shale.展开更多
There are some factors,such as the topographic relief,sedimentary thickness and thermal conductivity, magmatic activity and thermal cooling,influencing the seafloor heat flow and the evolution of lithosphere structure...There are some factors,such as the topographic relief,sedimentary thickness and thermal conductivity, magmatic activity and thermal cooling,influencing the seafloor heat flow and the evolution of lithosphere structure in southwest sub-basin(SWSB),South China Sea.On the base of the geological structure characteristic of SWSB this paper will discuss some other factors including thermal anomaly area,dike produced by magma intrusion and lithosphere relief,by modeling and calculating.Calculating results indicate partial areas where temperature is higher than vicinity in the lithosphere,which we call thermal anomaly here containing thermal anomaly area and dike in this paper,could decrease heat flow below,increase above,and gradually increase to two sides;heat flow in upwelling parts of lithosphere is usually higher than sinking parts,and in the middle is of a gradual transition.展开更多
The relationship between the upper ocean thermal structure and the genesis locations of tropical cyclones (TCs) in the South China Sea (SCS) is investigated by using the Joint Typhoon Warning Center (JTWC) best-track ...The relationship between the upper ocean thermal structure and the genesis locations of tropical cyclones (TCs) in the South China Sea (SCS) is investigated by using the Joint Typhoon Warning Center (JTWC) best-track archives and high resolution (1/4 degree) temperature analyses of the world's oceans in this paper. In the monthly mean genesis positions of TCs from 1945 to 2005 in the SCS, the mean sea surface temperature (SST) was 28.8℃ and the mean depth of 26℃ water was 53.1 m. From the monthly distribution maps of genesis positions of TCs, SST and the depth of 26℃ water in the SCS, we discovered that there existed regions with SST exceeding 26℃ and 26℃ water depth exceeding 50 m where no tropical cyclones formed from 1945 to 2005 in the SCS, which suggests that there were other factors unfavorable for TC formation in these regions.展开更多
Empirical Orthogonal Function (EOF) analysis is used in this study to generate main eigenvector fields of historical temperature for the China Seas (here referring to Chinese marine territories) and adjacent waters fr...Empirical Orthogonal Function (EOF) analysis is used in this study to generate main eigenvector fields of historical temperature for the China Seas (here referring to Chinese marine territories) and adjacent waters from 1930 to 2002 (510 143 profiles). A good temperature profile is reconstructed based on several subsurface in situ temperature observations and the thermocline was estimated using the model. The results show that: 1) For the study area, the former four principal components can explain 95% of the overall variance, and the vertical distribution of temperature is most stable using the in situ temperature observations near the surface. 2) The model verifications based on the observed CTD data from the East China Sea (ECS), South China Sea (SCS) and the areas around Taiwan Island show that the reconstructed profiles have high correlation with the observed ones with the confidence level >95%, especially to describe the characteristics of the thermocline well. The average errors between the reconstructed and observed profiles in these three areas are 0.69°C, 0.52°C and 1.18°C respectively. It also shows the model RMS error is less than or close to the climatological error. The statistical model can be used to well estimate the temperature profile vertical structure. 3) Comparing the thermocline characteristics between the reconstructed and observed profiles, the results in the ECS show that the average absolute errors are 1.5m, 1.4 m and 0.17°C/m, and the average relative errors are 24.7%, 8.9% and 22.6% for the upper, lower thermocline boundaries and the gradient, respectively. Although the relative errors are obvious, the absolute error is small. In the SCS, the average absolute errors are 4.1 m, 27.7 m and 0.007°C/m, and the average relative errors are 16.1%, 16.8% and 9.5% for the upper, lower thermocline boundaries and the gradient, respectively. The average relative errors are all <20%. Although the average absolute error of the lower thermocline boundary is considerable, but contrast to the spatial scale of average depth of the lower thermocline boundary (165 m), the average relative error is small (16.8%). Therefore the model can be used to well estimate the thermocline.展开更多
Lake Victoria is the second (excl. Caspian Sea) largest lake in the world by surface area and 7th by Volume. The lake and catchment territories are shared between three countries, Kenya, Uganda and Tanzania. A researc...Lake Victoria is the second (excl. Caspian Sea) largest lake in the world by surface area and 7th by Volume. The lake and catchment territories are shared between three countries, Kenya, Uganda and Tanzania. A research was carried out during 1990-1992 exploring the changes of the thermo-chemical structure occurred after the invasion of Nile Perch. Results of changes of physico-chemical (Temperature, DO and pH) conditions are summarized in this paper. The anoxic conditions by space and time were enhanced. Enhancement of pollutant supply from anthropogenic developments of terrestrial sources and atmospheric dust deposition accompanied by the deleterious effects of the Nile Perch invasion caused enhancement of anoxia in the lake in space and time. The combination of bottom-up nutrient supply and strong mixing conditions, expressed as low RTR values accelerate phytoplankton growth rate and production. The surplus of organic matter originated from algal biomass, enhanced anoxia.展开更多
In this paper, the authors used the Princeton Ocean Model (POM) to simulate the seasonal evolu- tions of circulation and thermal structure in the Yellow Sea. The simulated circulation showed that the Yellow Sea Warm C...In this paper, the authors used the Princeton Ocean Model (POM) to simulate the seasonal evolu- tions of circulation and thermal structure in the Yellow Sea. The simulated circulation showed that the Yellow Sea Warm Current (YSWC) was a compensation current of monsoon-driven current, and that in winter, the YSWC became stronger with depth, and could flow across the Bohai Strait in the north. Sensitivity and control- ling tests led to the following conclusions. In winter, the direction of the Yellow Sea Coastal Current in the sur- face layer was controlled partly by tide instead of wind. In summer, a cyclonic horizontal gyre existed in the middle and eastern parts of the Yellow Sea below 10 m. The downwelling in upper layer and upwelling in lower layer were somehow similar to Hu et al. (1991) conceptual model. The calculated thermal structure showed an obvious northward extending YSWC tongue in winter, its position and coverage of the Yellow Sea Cold Water Mass in summer.展开更多
In this paper,the characteristics of the lateral variations of the deep heat flow and Hthospheric geotemperature distribution in Yunnan have been studied,and the lithospheric geothermal structure has been divided into...In this paper,the characteristics of the lateral variations of the deep heat flow and Hthospheric geotemperature distribution in Yunnan have been studied,and the lithospheric geothermal structure has been divided into three types,i.e.the geothermal structure in the typical modern tectonically active region,transitional geological region and stable geological region.Finally,the relationship between the geotherm and seismicitv has been discussed.展开更多
Mantle xenoliths brought up by Cenozoic volcanic rocks onto the earth’s surface may provide direct information about the upper mantle beneath the volcanic region. This paper presents the study on mantle xenoliths col...Mantle xenoliths brought up by Cenozoic volcanic rocks onto the earth’s surface may provide direct information about the upper mantle beneath the volcanic region. This paper presents the study on mantle xenoliths collected from Haoti village, Dangchang County, Gansu Province, western China. The main purpose of the study is to gain an insight into the thermal structure and rheology of the upper mantle beneath the region. The results show that the upper mantle of the region is composed mainly of spinel lherzolite at shallower depth (52～75km), and garnet lherzolite at greater depth (greater than 75km), instead of harzburgite and dunite as proposed by some previous studies. The upper mantle geotherm derived from the equilibrium temperatures and pressures of xenoliths from the region is lower than that of North China, and is somewhat closer to the Oceanic geotherm. The crust-mantle boundary is determined from the geotherm to be at about 52km, and the Moho seems to be the transition zone of lower crust material with spinel lherzolite. If we take 1280℃ as the temperature of the top of asthenosphere, then the lithosphere-asthenosphere boundary should be at about 120km depth. The differential stress of the upper mantle is determined by using recrystallized grain size piezometry, while the strain rate and equivalent viscosity are determined by using the high temperature flow law of peridotite. The differential stress, strain rate and viscosity profiles constructed on the basis of the obtained values indicate that asthenospheric diapir occurred in this region during the Cenozoic time, resulting in the corresponding thinning of the lithosphere. However, the scale and intensity of the diapir was significantly less than that occurring in the North China region. Moreover, numerous small-scale shear zones with localized deformation might occur in the lithospheric mantle, as evidenced by the extensive occurrence of xenoliths with tabular equigranular texture.展开更多
The assembled form of thick-wall glass fiber reinforced plastics (GFRP) tube and 0Cr18Ni9 austenitic stainless steel pipes was designed as the radius thermal-insulating and load-supporting structure in cryogenic vesse...The assembled form of thick-wall glass fiber reinforced plastics (GFRP) tube and 0Cr18Ni9 austenitic stainless steel pipes was designed as the radius thermal-insulating and load-supporting structure in cryogenic vessels. In order to study the thermal leakage and gap changes on the support structure, as well as radius temperature and stress distribution on GFRP tube, an experimental investigation has been taken. The results indicate that the support structure is proved to fit well as thermal-insulating and load-supporting part in cryo-genic vessels, furthermore has high security during cryogenic applications.展开更多
The poor thermal stability and high sensitivity severely hinder the practical application of hexanitrohexaazaisowurtzitane(CL-20).Herein,a kind of novel core@double-shell CL-20 based energetic composites were fabricat...The poor thermal stability and high sensitivity severely hinder the practical application of hexanitrohexaazaisowurtzitane(CL-20).Herein,a kind of novel core@double-shell CL-20 based energetic composites were fabricated to address the above issues.The coordination complexes which consist of natural polyphenol tannic acid(TA) and Fe~Ⅲ were chosen to construct the inner shell,while the graphene sheets were used to build the outer shell.The resulting CL-20/TA-Fe~Ⅲ/graphene composites exhibited simultaneously improved thermal stability and safety performance with only 1 wt% double-shell content,which should be ascribed to the intense physical encapsulation effect from inner shell combined with the desensitization effect of carbon nano-materials from outer shell.The phase transition(ε to γ) temperature increased from 173.70 ℃ of pure CL-20 to 191.87℃ of CL-20/TA-Fe~Ⅲ/graphene composites.Meanwhile,the characteristic drop height(H_(50)) dramatically increased from 14.7 cm of pure CL-20 to112.8 cm of CL-20/TA-Fe~Ⅲ/graphene composites,indicating much superior safety performance after the construction of the double-shell structure.In general,this work has provided an effective and versatile strategy to conquer the thermal stability and safety issues of CL-20 and contributes to the future application of high energy density energetic materials.展开更多
Ag-In intermetallic alloys were produced by using vacuum arc furnace. Differential Scanning Calorimetry(DSC) and Energy Dispersive X-Ray Spectrometry(EDX) were used to determine the thermal properties and chemical com...Ag-In intermetallic alloys were produced by using vacuum arc furnace. Differential Scanning Calorimetry(DSC) and Energy Dispersive X-Ray Spectrometry(EDX) were used to determine the thermal properties and chemical composition of the phases respectively. Microhardness values of Ag-In intermetallics were calculated with Vickers hardness measurement method. According to the experimental results, Ag-34 wt%In intermetallic system generated the best results of energy saving and storage compared to other intermetallic systems. Also from the microhardness results, it was observed that intermetallic alloys were harder than pure silver and Ag-26 wt%In system had the highest microhardness value with 143.45 kg/mm^(2).展开更多
Through equilibrium and non-equilibrium molecular dynamics simulations,we have demonstrated the inhibitory effect of composition graded interface on thermal transport behavior in lateral heterostructures.Specifically,...Through equilibrium and non-equilibrium molecular dynamics simulations,we have demonstrated the inhibitory effect of composition graded interface on thermal transport behavior in lateral heterostructures.Specifically,we investigated the influence of composition gradient length and heterogeneous particles at the silicene/germanene(SIL/GER)heterostructure interface on heat conduction.Our results indicate that composition graded interface at the interface diminishes the thermal conductivity of the heterostructure,with a further reduction observed as the length increases,while the effect of the heterogeneous particles can be considered negligible.To unveil the influence of composition graded interface on thermal transport,we conducted phonon analysis and identified the presence of phonon localization within the interface composition graded region.Through these analyses,we have determined that the decrease in thermal conductivity is correlated with phonon localization within the heterostructure,where a stronger degree of phonon localization signifies poorer thermal conductivity in the material.Our research findings not only contribute to understanding the impact of interface gradient-induced phonon localization on thermal transport but also offer insights into the modulation of thermal conductivity in heterostructures.展开更多
Some living organisms with hierarchical structures in nature have received extensive attention in various fields.The hierarchical structure with multiple pores,a large number of solid-gas interfaces and tortuous condu...Some living organisms with hierarchical structures in nature have received extensive attention in various fields.The hierarchical structure with multiple pores,a large number of solid-gas interfaces and tortuous conduction paths provide a new direction for the development of thermal insulation materials,making the living creatures under these extreme conditions become the bionic objects of scientific researchers.In this review,the research progress of bionic hierarchical structure in the field of heat insulation is highlighted.Polar bears,cocoons,penguin feathers and wool are typical examples of heat preservation hierarchy in nature to introduce their morphological characteristics.At the same time,the thermal insulation mechanism,fractal model and several preparation methods of bionic hierarchical structures are emphatically discussed.The application of hierarchical structures in various fields,especially in thermal insulation and infrared thermal stealth,is summarised.Finally,the hierarchical structure is prospected.展开更多
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB 41000000)National Basic Research Program of China(Grant No.2015CB856106)National Natural Science Foundation of China(41774105,41820104004,41688103).
文摘The thermal structure of the continental subduction zone can be deduced from high-pressure and ultra-high-pressure rock samples or numerical simulation.However,petrological data indicate that the temperature of subducted continental plates is generally higher than that derived from numerical simulation.In this paper,a two-dimensional kinematic model is used to study the thermal structure of continental subduction zones,with or without a preceding oceanic slab.The results show that the removal of the preceding oceanic slab can effectively increase the slab surface temperature of the continental subduction zone in the early stage of subduction.This can sufficiently explain the difference between the cold thermal structure obtained from previous modeling results and the hot thermal structure obtained from rock sample data.
基金The National Natural Science Foundation of China under contract Nos 41705081 and 41906005the Innovation Special Zone Project under contract No.18-H863-05-ZT-001-012-06the Open Project Fund of the Laboratory for Regional Oceanography and Numerical Modeling,Pilot National Laboratory for Marine Science and Technology(Qingdao)under contract No.2019A05.
文摘The sensitive area of targeted observations for short-term(7 d)prediction of vertical thermal structure(VTS)in summer in the Yellow Sea was investigated.We applied the Conditional Nonlinear Optimal Perturbation(CNOP)method and an adjoint-free algorithm with the Regional Ocean Modeling System(ROMS).We used vertical integration of CNOP-type temperature errors to locate the sensitive areas,where reduction of initial errors is expected to yield the greatest improvement in VTS prediction for the selected verification area.The identified sensitive areas were northeast−southwest orientated northeast to the verification area,which were possibly related to the southwestward background currents.Then,we performed a series of sensitivity experiments to evaluate the effectiveness of the identified sensitive areas.Results show that initial errors in the identified sensitive areas had the greatest negative effect on VTS prediction in the verification area compared to errors in other areas(e.g.,the verification area and areas to its east and northeast).Moreover,removal of initial errors through deploying simulated observations in the identified sensitive areas led to more refined prediction than correction of initial conditions in the verification area itself.Our results suggest that implementation of targeted observation in the CNOP-based sensitive areas is an effective method to improve short-term prediction of VTS in summer in the Yellow Sea.
基金This research was supported by grant from the National Natural Science Foundation of China:Study of radioactive heat in the mantle with Geoneutrino(No.41874100).
文摘Guangdong Province in Southeast China is noted for its numerous geothermal resources due to tectonic episodes,mainly occurred during the Cretaceous.The surface heat flow and geothermal gradient are the most direct ways to understand the temperature of the Earth.However,geothermal resources are poorly utilized in Guangdong Province due to limited numbers of boreholes and surficial hydrothermal fluids.To improve the understanding of underground temperature distribution in Guangdong Province,we have applied power-density spectral analysis to aeromagnetic anomaly data to calculate the depth of the Curie isothermal surface.Upward continuation is applied and tested to the magnetic data.The calculated Curie isotherm is between 18.5 km and 25 km below surface.The fluctuation in the depth range reflects lateral thermal perturbations in the Guangdong crust.In particular,the eastern,northern,western and coastline areas of the province have a relatively shallow Curie isotherm.By comparing the surface heat flow,geothermal gradient,distribution of Mesozoic granite-volcanic rocks,and natural hot springs,we conclude that during Mesozoic,magmatism exerted great influence on the deep thermal state of Guangdong Province.A shallow Curie isotherm surface,as well as numerous natural hot springs and high heat flow,show clear signatures of shallow heat sources.
基金funded by the National Natural Science Foundation of China (Grant Nos.41402219, 41302202,41125010,41302202,and 91114202)
文摘The Bohai Bay Basin is a region where part of the North China Craton has been thinned and destroyed. It has experienced two periods of crustal thinning that occurred during the Cretaceous and Paleogene, but investigations of its Mesozoic and Cenozoic lithospheric thermal structure are limited. Therefore, in this study,the distributions of mantle heat flow, crustal heat flow, and Moho temperatures during the Meso-Cenozoic are calculated based on analyses of the thermal history of the Bohai Bay Basin. The results indicate that the ratio of mantle heat flow to surface heat flow peaked during the late stages of the early Cretaceous and during the middle to late Paleogene. The corresponding mantle heat flow was more than 65% of the surface heat flow. Moho temperatures reached three peaks: 900-1100℃ in the late stages of the early Cretaceous;820-900℃ in the middle to late Paleogene; and(in the Linqing Depression, Cangxian Uplift, and Jizhong Depression) 770-810℃ during the early Neogene. These results reveal that the Bohai Bay Basin experienced significant geological change during the Cretaceous, including the transformation of lithospheric thermal structure from "cold mantle and hot crust" before the Cretaceous to "hot mantle and cold crust" after the Cretaceous. The results also indicate that the basin experienced two large-scale rifting events.Therefore, this work may provide the thermal parameters for further investigations of the geodynamic evolution of eastern China.
文摘The Qaidam Basin is a petroleum province in Northeastern Qinghai—Tibetan plateau, China. The Basin is bounded by the Aljin Mountains to the Northwest, the Qilian Mountains to the Northeast, the Qimantager Mountains to the Southeast and East Kunlun Mountains to the Southwest. The average elevation of the basin and these mountains are 2700m and 3000～ 5000 m respect to the sea level, respectively. The basin was developed on the pre\|Mesozoic basement. Thickness of Tertiary system is more than 10000m in the basin,but Quaternary is mainly in the eastern basin with thickness more than 3000m. The lithology in Mesozoic and Cenozoic of the basin are mainly sandstone, shale, calcic rocks and the interlayers of sandstone and shale.
文摘There are some factors,such as the topographic relief,sedimentary thickness and thermal conductivity, magmatic activity and thermal cooling,influencing the seafloor heat flow and the evolution of lithosphere structure in southwest sub-basin(SWSB),South China Sea.On the base of the geological structure characteristic of SWSB this paper will discuss some other factors including thermal anomaly area,dike produced by magma intrusion and lithosphere relief,by modeling and calculating.Calculating results indicate partial areas where temperature is higher than vicinity in the lithosphere,which we call thermal anomaly here containing thermal anomaly area and dike in this paper,could decrease heat flow below,increase above,and gradually increase to two sides;heat flow in upwelling parts of lithosphere is usually higher than sinking parts,and in the middle is of a gradual transition.
文摘The relationship between the upper ocean thermal structure and the genesis locations of tropical cyclones (TCs) in the South China Sea (SCS) is investigated by using the Joint Typhoon Warning Center (JTWC) best-track archives and high resolution (1/4 degree) temperature analyses of the world's oceans in this paper. In the monthly mean genesis positions of TCs from 1945 to 2005 in the SCS, the mean sea surface temperature (SST) was 28.8℃ and the mean depth of 26℃ water was 53.1 m. From the monthly distribution maps of genesis positions of TCs, SST and the depth of 26℃ water in the SCS, we discovered that there existed regions with SST exceeding 26℃ and 26℃ water depth exceeding 50 m where no tropical cyclones formed from 1945 to 2005 in the SCS, which suggests that there were other factors unfavorable for TC formation in these regions.
基金supported by the Pilot Project of Knowledge Innovation Program,Chinese Academy of Sciences(Grant NoKZCX2-EW-QN205)the National Natural Science Foundation of China(No41176043)the Program of Key Laboratory of Marine Geology and Environment,Institute of Oceanology,Chinese Academy of Sciences(Grant NoMGE2011KG05)
基金Supported by the Knowledge Innovation Program of Chinese Academy of Sciences (No.KZCX-3W-222 KZCX2-YW-Q11-02)+1 种基金National Basic Research Program of China (No.2007CB411802 2006CB403601)
文摘Empirical Orthogonal Function (EOF) analysis is used in this study to generate main eigenvector fields of historical temperature for the China Seas (here referring to Chinese marine territories) and adjacent waters from 1930 to 2002 (510 143 profiles). A good temperature profile is reconstructed based on several subsurface in situ temperature observations and the thermocline was estimated using the model. The results show that: 1) For the study area, the former four principal components can explain 95% of the overall variance, and the vertical distribution of temperature is most stable using the in situ temperature observations near the surface. 2) The model verifications based on the observed CTD data from the East China Sea (ECS), South China Sea (SCS) and the areas around Taiwan Island show that the reconstructed profiles have high correlation with the observed ones with the confidence level >95%, especially to describe the characteristics of the thermocline well. The average errors between the reconstructed and observed profiles in these three areas are 0.69°C, 0.52°C and 1.18°C respectively. It also shows the model RMS error is less than or close to the climatological error. The statistical model can be used to well estimate the temperature profile vertical structure. 3) Comparing the thermocline characteristics between the reconstructed and observed profiles, the results in the ECS show that the average absolute errors are 1.5m, 1.4 m and 0.17°C/m, and the average relative errors are 24.7%, 8.9% and 22.6% for the upper, lower thermocline boundaries and the gradient, respectively. Although the relative errors are obvious, the absolute error is small. In the SCS, the average absolute errors are 4.1 m, 27.7 m and 0.007°C/m, and the average relative errors are 16.1%, 16.8% and 9.5% for the upper, lower thermocline boundaries and the gradient, respectively. The average relative errors are all <20%. Although the average absolute error of the lower thermocline boundary is considerable, but contrast to the spatial scale of average depth of the lower thermocline boundary (165 m), the average relative error is small (16.8%). Therefore the model can be used to well estimate the thermocline.
文摘Lake Victoria is the second (excl. Caspian Sea) largest lake in the world by surface area and 7th by Volume. The lake and catchment territories are shared between three countries, Kenya, Uganda and Tanzania. A research was carried out during 1990-1992 exploring the changes of the thermo-chemical structure occurred after the invasion of Nile Perch. Results of changes of physico-chemical (Temperature, DO and pH) conditions are summarized in this paper. The anoxic conditions by space and time were enhanced. Enhancement of pollutant supply from anthropogenic developments of terrestrial sources and atmospheric dust deposition accompanied by the deleterious effects of the Nile Perch invasion caused enhancement of anoxia in the lake in space and time. The combination of bottom-up nutrient supply and strong mixing conditions, expressed as low RTR values accelerate phytoplankton growth rate and production. The surplus of organic matter originated from algal biomass, enhanced anoxia.
基金Contribution No. 4616 from Institute of Oceanology, CAS. Project No.40406025 supported by NSFC.
文摘In this paper, the authors used the Princeton Ocean Model (POM) to simulate the seasonal evolu- tions of circulation and thermal structure in the Yellow Sea. The simulated circulation showed that the Yellow Sea Warm Current (YSWC) was a compensation current of monsoon-driven current, and that in winter, the YSWC became stronger with depth, and could flow across the Bohai Strait in the north. Sensitivity and control- ling tests led to the following conclusions. In winter, the direction of the Yellow Sea Coastal Current in the sur- face layer was controlled partly by tide instead of wind. In summer, a cyclonic horizontal gyre existed in the middle and eastern parts of the Yellow Sea below 10 m. The downwelling in upper layer and upwelling in lower layer were somehow similar to Hu et al. (1991) conceptual model. The calculated thermal structure showed an obvious northward extending YSWC tongue in winter, its position and coverage of the Yellow Sea Cold Water Mass in summer.
基金The work was supported by the Applied and Basic Research Foundation of Yunnan Province (93D045Q), China
文摘In this paper,the characteristics of the lateral variations of the deep heat flow and Hthospheric geotemperature distribution in Yunnan have been studied,and the lithospheric geothermal structure has been divided into three types,i.e.the geothermal structure in the typical modern tectonically active region,transitional geological region and stable geological region.Finally,the relationship between the geotherm and seismicitv has been discussed.
文摘Mantle xenoliths brought up by Cenozoic volcanic rocks onto the earth’s surface may provide direct information about the upper mantle beneath the volcanic region. This paper presents the study on mantle xenoliths collected from Haoti village, Dangchang County, Gansu Province, western China. The main purpose of the study is to gain an insight into the thermal structure and rheology of the upper mantle beneath the region. The results show that the upper mantle of the region is composed mainly of spinel lherzolite at shallower depth (52～75km), and garnet lherzolite at greater depth (greater than 75km), instead of harzburgite and dunite as proposed by some previous studies. The upper mantle geotherm derived from the equilibrium temperatures and pressures of xenoliths from the region is lower than that of North China, and is somewhat closer to the Oceanic geotherm. The crust-mantle boundary is determined from the geotherm to be at about 52km, and the Moho seems to be the transition zone of lower crust material with spinel lherzolite. If we take 1280℃ as the temperature of the top of asthenosphere, then the lithosphere-asthenosphere boundary should be at about 120km depth. The differential stress of the upper mantle is determined by using recrystallized grain size piezometry, while the strain rate and equivalent viscosity are determined by using the high temperature flow law of peridotite. The differential stress, strain rate and viscosity profiles constructed on the basis of the obtained values indicate that asthenospheric diapir occurred in this region during the Cenozoic time, resulting in the corresponding thinning of the lithosphere. However, the scale and intensity of the diapir was significantly less than that occurring in the North China region. Moreover, numerous small-scale shear zones with localized deformation might occur in the lithospheric mantle, as evidenced by the extensive occurrence of xenoliths with tabular equigranular texture.
文摘The assembled form of thick-wall glass fiber reinforced plastics (GFRP) tube and 0Cr18Ni9 austenitic stainless steel pipes was designed as the radius thermal-insulating and load-supporting structure in cryogenic vessels. In order to study the thermal leakage and gap changes on the support structure, as well as radius temperature and stress distribution on GFRP tube, an experimental investigation has been taken. The results indicate that the support structure is proved to fit well as thermal-insulating and load-supporting part in cryo-genic vessels, furthermore has high security during cryogenic applications.
基金financially supported by the National Natural Science Foundation of China (Grant No. 22275173)the Open Project of State Key Laboratory of Environment-friendly Energy Materials (Grant No. 22kfhg10)。
文摘The poor thermal stability and high sensitivity severely hinder the practical application of hexanitrohexaazaisowurtzitane(CL-20).Herein,a kind of novel core@double-shell CL-20 based energetic composites were fabricated to address the above issues.The coordination complexes which consist of natural polyphenol tannic acid(TA) and Fe~Ⅲ were chosen to construct the inner shell,while the graphene sheets were used to build the outer shell.The resulting CL-20/TA-Fe~Ⅲ/graphene composites exhibited simultaneously improved thermal stability and safety performance with only 1 wt% double-shell content,which should be ascribed to the intense physical encapsulation effect from inner shell combined with the desensitization effect of carbon nano-materials from outer shell.The phase transition(ε to γ) temperature increased from 173.70 ℃ of pure CL-20 to 191.87℃ of CL-20/TA-Fe~Ⅲ/graphene composites.Meanwhile,the characteristic drop height(H_(50)) dramatically increased from 14.7 cm of pure CL-20 to112.8 cm of CL-20/TA-Fe~Ⅲ/graphene composites,indicating much superior safety performance after the construction of the double-shell structure.In general,this work has provided an effective and versatile strategy to conquer the thermal stability and safety issues of CL-20 and contributes to the future application of high energy density energetic materials.
基金Nev?ehir Hac?Bekta?Veli Runiversity Scientific Research Projects Coordination Unit (No. NEüLüP16/2F3)。
文摘Ag-In intermetallic alloys were produced by using vacuum arc furnace. Differential Scanning Calorimetry(DSC) and Energy Dispersive X-Ray Spectrometry(EDX) were used to determine the thermal properties and chemical composition of the phases respectively. Microhardness values of Ag-In intermetallics were calculated with Vickers hardness measurement method. According to the experimental results, Ag-34 wt%In intermetallic system generated the best results of energy saving and storage compared to other intermetallic systems. Also from the microhardness results, it was observed that intermetallic alloys were harder than pure silver and Ag-26 wt%In system had the highest microhardness value with 143.45 kg/mm^(2).
基金Project supported by the National Natural Science Foundation of China (Grant No.12104291)。
文摘Through equilibrium and non-equilibrium molecular dynamics simulations,we have demonstrated the inhibitory effect of composition graded interface on thermal transport behavior in lateral heterostructures.Specifically,we investigated the influence of composition gradient length and heterogeneous particles at the silicene/germanene(SIL/GER)heterostructure interface on heat conduction.Our results indicate that composition graded interface at the interface diminishes the thermal conductivity of the heterostructure,with a further reduction observed as the length increases,while the effect of the heterogeneous particles can be considered negligible.To unveil the influence of composition graded interface on thermal transport,we conducted phonon analysis and identified the presence of phonon localization within the interface composition graded region.Through these analyses,we have determined that the decrease in thermal conductivity is correlated with phonon localization within the heterostructure,where a stronger degree of phonon localization signifies poorer thermal conductivity in the material.Our research findings not only contribute to understanding the impact of interface gradient-induced phonon localization on thermal transport but also offer insights into the modulation of thermal conductivity in heterostructures.
文摘Some living organisms with hierarchical structures in nature have received extensive attention in various fields.The hierarchical structure with multiple pores,a large number of solid-gas interfaces and tortuous conduction paths provide a new direction for the development of thermal insulation materials,making the living creatures under these extreme conditions become the bionic objects of scientific researchers.In this review,the research progress of bionic hierarchical structure in the field of heat insulation is highlighted.Polar bears,cocoons,penguin feathers and wool are typical examples of heat preservation hierarchy in nature to introduce their morphological characteristics.At the same time,the thermal insulation mechanism,fractal model and several preparation methods of bionic hierarchical structures are emphatically discussed.The application of hierarchical structures in various fields,especially in thermal insulation and infrared thermal stealth,is summarised.Finally,the hierarchical structure is prospected.
