Abnormally low pressure commonly develops in petroliferous basins.It is closely associated with hydrocarbon distribution and can hinder safe drilling operations.Potentiometric surface is one of the causes of abnormall...Abnormally low pressure commonly develops in petroliferous basins.It is closely associated with hydrocarbon distribution and can hinder safe drilling operations.Potentiometric surface is one of the causes of abnormally low pressure,but the relationship between such surface and abnormal pressure has not attracted much research attention.In this paper,a method is proposed for quantifying the potentiometric surface of the tight oil reservoir of the Upper Triassic Yanchang Formation in the Zhenjing area,southern Ordos Basin,China.This method involves screening pressure data that reflect real pore pressure conditions underground and analyzing the formation sealing conditions in the reservoir based on fracture development and the chemical characteristics of the formation water.The relationship between the potentiometric surface and the abnormally low pressure observed in the study area is discussed.The results show that the pressure coefficient of the Yanchang Formation in the Zhenjing area is 0.85e1.02,with an average of 0.93,indicating a state between abnormally low pressure and normal pressure.The Yanchang Formation has complex sealing conditions,with favorable overall sealing and a locally open hydrodynamic environment controlled by sand body connectivity and fault activity.We proposed a method to calculate the potentiometric surface using the measured pressure data with a pressure coefficient close to 1.The potentiometric surface is 1040e1200 m,with a high value in the northwest and a low value in the southeast,and it is 0e350 m below the ground level.The pressure coefficient was calibrated with an average of 1,with the potentiometric surface used as the starting point,indicating that the low pressure coefficient may be caused by the potentiometric surface below the ground level.The results have theoretical implications for the analysis of formation pressure characteristics in areas or basins with comparable geological conditions,and practical implications for the analysis and development of oil and gas.展开更多
The Cambrian Qiongzhusi Formation in the Sichuan Basin harbors significant potential for shale gas harvesting.However,systematic disparities in mineral composition and reservoir architecture have been observed between...The Cambrian Qiongzhusi Formation in the Sichuan Basin harbors significant potential for shale gas harvesting.However,systematic disparities in mineral composition and reservoir architecture have been observed between intra-and extra-trough reservoirs within the Deyang-Anyue Rift Trough.These variations were primarily determined by divergences in the sedimentary environments developed during the evolution of the rift trough,which were a main factor in fostering the heterogeneous distribution of shale gas enrichment found today.However,the genetic mechanisms that govern reservoir heterogeneity across distinct structural domains(intra-trough,trough margin,and extra-trough)remain poorly understood,particularly regarding the coupling relationships between depositional environments,reservoir characteristics,and gas-bearing properties.This study adopts a multidisciplinary approach to investigating this issue that integrates core analysis,well-log interpretations,and geochemical data.Through systematic comparisons conducted using X-ray diffraction mineralogy,organic carbon quantification,and spontaneous imbibition experiments,we characterize the mineral assemblages,organic geochemical signatures,and pore structures found across the three structural domains of the Deyang-Anyue Rift Trough.The key findings are as follows:(1)The depositional environment is the main influence on reservoir distribution and organic matter enrichment,with intra-trough shales exhibiting a higher abundance of organic matter than their trough-margin and extra-trough counterparts.(2)Enhanced brittleness in intra-trough zones correlates with the predominance of biogenic silica therein.(3)Synergistic organic-inorganic interactions govern pore system development.(4)Gas-bearing capacity is jointly determined by effective porosity and organic matter content.These findings establish the rift trough as a preferential exploration target,providing critical geological guidance for optimizing shale gas exploration strategies in the Cambrian Qiongzhusi Formation.展开更多
Enzyme Induced Carbonate Precipitation(EICP)has been extensively investigated as a promising approach to improve engineering properties of soil,while Eggshell Powder(ESP)is an agricultural waste that effectively fills...Enzyme Induced Carbonate Precipitation(EICP)has been extensively investigated as a promising approach to improve engineering properties of soil,while Eggshell Powder(ESP)is an agricultural waste that effectively fills soil pores.The ESP provides abundant nucleation at sites for the EICP process,further promoting the effective precipitation of calcium carbonate.The research presented in this paper investigated the Soil Water Characteristic Curves(SWCC),permeability coefficient,and microstructure of expansive soil before and after EICP and EICP+ESP modification.A series of laboratory experiments were conducted,including soil water characteristic tests,permeability tests and Scanning Electron Microscopy(SEM).The results proved that the addition of EICP and EICP+ESP into natural expansive soil resulted in a gradual decline in air entry value,residual water content,and permeability coefficient,indicating an increase in water retention capacity and a decrease in permeability.Furthermore,with the intrusion of EICP and EICP+ESP,the contact between particles becomes smoother,and the soil pores become more equally distributed.Ultimately,there was an enhancement in water retention capacity of the natural expansive soil.This study emphasizes the synergistic potential of combining EICP and EICP+ESP as stabilizing additives to enhance the water retention capacity of expansive soil.Moreover,the reuse of ESP provides a sustainable solution for the resource utilization of agricultural waste and the improvement of expansive soil using bio-inspired methods.展开更多
This study compares the microstructural evolution,dynamic recrystallization(DRX)behavior,tensile properties,and age-hardenability between the newly developed high-speed-extrudable BA56 alloy and those of the widely re...This study compares the microstructural evolution,dynamic recrystallization(DRX)behavior,tensile properties,and age-hardenability between the newly developed high-speed-extrudable BA56 alloy and those of the widely recognized AZ31 alloy in industry.Unlike the AZ31 alloy,which retains partially unrecrystallized grains,the high-speed-extruded BA56 alloy demonstrates a coarser but entirely recrystallized and more homogeneous microstructure.The fine-grained structure and abundant Mg_(3)Bi_(2) particles in the BA56 extrusion billet significantly enhance its DRX behavior,thus enabling rapid and complete recrystallization during extrusion.The BA56 alloy contains band-like fragmented Mg_(3)Bi_(2) particles and numerous fine Mg_(3)Bi_(2) particles distributed throughout the material,in contrast to the sparse Al_(8)Mn_(5) particles in the AZ31 alloy.These features contribute to superior mechanical properties of the BA56 alloy,which achieves tensile yield and ultimate tensile strengths of 205 and 292 MPa,respectively,compared to 196 and 270 MPa for the AZ31 alloy.The superior strength of the BA56 alloy,even with its coarser grain size,can be explained by its elevated Hall-Petch constant and the strengthening contribution from the fine Mg_(3)Bi_(2) particles.Additionally,the BA56 alloy demonstrates significant age-hardenability,achieving a 22%enhancement in hardness following T5 aging,attributed to the precipitation of nanoscale Mg_(3)Bi_(2) and Mg_(17)Al_(12) phases.By contrast,the AZ31 alloy shows minimal hardening due to the absence of precipitate formation during aging.These findings suggest that the BA56 alloy is a promising candidate for the production of extruded Mg components requiring a combination of high productivity,superior mechanical performance,and wide-ranging process adaptability.展开更多
Liquid hydrogen has attracted much attention due to its high energy storage density and suitability for long-distance transportation.An efficient hydrogen liquefaction process is the key to obtaining liquid hydrogen.I...Liquid hydrogen has attracted much attention due to its high energy storage density and suitability for long-distance transportation.An efficient hydrogen liquefaction process is the key to obtaining liquid hydrogen.In an effort to determine the parameter optimization of the hydrogen liquefaction process,this paper employed process simulation software Aspen HYSYS to simulate the hydrogen liquefaction process.By establishing a dynamic model of the unit module,this study carried out dynamic simulation optimization based on the steady-state process and process parameters of the hydrogen liquefaction process and analyzed the dynamic characteristics of the process.Based on the pressure drop characteristic experiment,an equation for the pressure drop in the heat exchanger was proposed.The heat transfer of hydrogen conversion was simulated and analyzed,and its accuracy was verified by comparison with the literature.The dynamic simulation of a plate-fin heat exchanger was carried out by coupling heat transfer simulation and the pressure drop experiment.The results show that the increase in inlet temperature(5℃and 10℃)leads to an increase in specific energy consumption(0.65%and 1.29%,respectively)and a decrease in hydrogen liquefaction rate(0.63%and 2.88%,respectively).When the inlet pressure decreases by 28.57%,the hydrogen temperature of the whole liquefaction process decreases and the specific energy consumption increases by 52.94%.The research results are of great significance for improving the operating efficiency of the refrigeration cycle and guiding the actual liquid hydrogen production.展开更多
China is tectonically composed of a series of plates and orogenic belts and has been influenced by the Pacific and Indian plates since the Late Paleozoic,forming a regular distribution of Mesozoic and Cenozoic granite...China is tectonically composed of a series of plates and orogenic belts and has been influenced by the Pacific and Indian plates since the Late Paleozoic,forming a regular distribution of Mesozoic and Cenozoic granites.As an important source of geothermal energy,granite is thefive elements of geothermal enrichment:geothermal sources;geothermal reservoirs;heat transmission;heat caprock;and heat preservation and it is possible to classify the types of geothermal resources in China according to their distribution in combination with neotectonic movements.China's geothermal energy can be divided into hydrothermal and hot dry rock types in basins and orogenic belts,respectively.Geothermal resources can be divided into hydrothermal,rock,magma,and hybrid geothermal types according to the heat carrier type.Basin geothermal resources are dominated by hydrothermal types,while geothermal energy in orogenic belts with granite includes both hydrothermal and hot dry rock types.Geothermal resources in China can be divided into 6 distinct geothermal regions and 13 subregions,of which the Southwest and Southeast China regions and the Qaidam-Qilian and Jiaoliao subregions in North China with Mesozoic and Cenozoic granites are the most favorable areas for high-temperature hydrothermal and hot dry rock sources.China has complex geological conditions,diverse types of geothermal resources,and broad prospects for development and utilization.Having performed extensive shallow hydrothermal geothermal development and utilization and completed various power generation tests,China's geothermal development and utilization is in a critical stage of transition from the direct utilization of shallow hydrothermal resources to high-temperature geothermal or hot dry rock power generation in middle and deep layers.Basic theoretical research,key technology breakthroughs,and policy incentives are the main issues that need to be addressed in the geothermal industry.展开更多
The diet of Bryconalestes tholloni from Mafoubou River, Sous-affluent of Niari River was studied by examining the stomach contents of 75 specimens captured using the cast nets. This study is the first realized on the ...The diet of Bryconalestes tholloni from Mafoubou River, Sous-affluent of Niari River was studied by examining the stomach contents of 75 specimens captured using the cast nets. This study is the first realized on the trophic ecology of a fish species of Niari Basin. Three stations were sampled monthly from July to December 2019. The diet was analyzed according to hydrological season and fish size. The vacuity coefficient is 27%, feeding habits of Bryconalestes tholloni were analyzed using the preponderance index which combines the occurrence percentage and the weight percentage. Bryconalestes tholloni is insectivorous (Ip = 95.54%) and becomes omnivorus to predominantly frugivorous, the preponderance index of fruits is equal to 93.6% in large individuals. There is no variation in diet according to the season. These results constitute a first database on the feeding habits Niari Basin fishes.展开更多
This study uses the PΔV term in the ideal gas equation PΔV = nRΔT to show how the 1-degree temperature increase that expands the occupied volume of a gas by ΔV against constant pressure P also causes the system to...This study uses the PΔV term in the ideal gas equation PΔV = nRΔT to show how the 1-degree temperature increase that expands the occupied volume of a gas by ΔV against constant pressure P also causes the system to increase its entropy by ΔS. As the volume available to a gas sample increases, the locations for disordered molecular relocation also increase. The causal agent linking a volume increase ΔV and an entropy increase ΔS is absolute temperature T measured in kelvin units. Since a volume increase is empirically observable while an increase in randomized molecular disorder is not, a per-kelvin increase in gas volume provides a method for estimating entropy increase. Both volume and entropy are extensive variables dependent upon the number of molecules in the system. Both are deemed to be at their absolute minima at the absolute zero of temperature. This study provides an insight into how a per-kelvin temperature increase causes both a linear increase in gas volume and a linear increase in gas entropy. When people talk about randomized disorder without specifying absolute temperature and molecule-count for the system, they are discussing a concept other than thermodynamic entropy.展开更多
THE China-Egypt Teda Suez Economic and Trade Cooperation Zone, or simply Teda Cooperation Zone, is located in Sokhna District of Suez Province, more than 120 kilometers away from Cairo, the capital of Egypt. It is amo...THE China-Egypt Teda Suez Economic and Trade Cooperation Zone, or simply Teda Cooperation Zone, is located in Sokhna District of Suez Province, more than 120 kilometers away from Cairo, the capital of Egypt. It is among the second batch of state-level overseas economic and trade cooperation zones approved by the Chinese government. Signboards bearing the phrase “A sign of development” can be seen everywhere in the park, marking the original intention of setting up this economic and trade cooperation zone.展开更多
China’s interests and future are closely linked to those of the world,and it wishes to work with all countries for common development and a community with a shared future for mankind,Chinese Vice President Wang Qisha...China’s interests and future are closely linked to those of the world,and it wishes to work with all countries for common development and a community with a shared future for mankind,Chinese Vice President Wang Qishan said at the 2019 World Economic Forum(WEF)in Davos,Switzerland on January 23.展开更多
ECOLOGICAL civilization is a new form of civilization that is based on industrial civilization and capitalizes on its strengths. It represents the material and spiritual achievements humankind has made by following th...ECOLOGICAL civilization is a new form of civilization that is based on industrial civilization and capitalizes on its strengths. It represents the material and spiritual achievements humankind has made by following the principles of maintaining harmony between man, nature, and society. It also reflects the civility and progress of a society. China has incorporated the building of ecological civilization into a five-sphere integrated plan to promote coordinated economic, political, cultural, social, and ecological advancement.展开更多
The BZ19-6 deep buried-hill structural belt in the southwest of Bozhong Sag,Bohai Bay Basin,is a newly discovered super-giant oil and gas bearing area.The study on its reservoirs is still in the early stage,and the ch...The BZ19-6 deep buried-hill structural belt in the southwest of Bozhong Sag,Bohai Bay Basin,is a newly discovered super-giant oil and gas bearing area.The study on its reservoirs is still in the early stage,and the characteristics and control factors of reservoir development are not understood deeply.In this paper,cores,sidewall cores,rock sections were analyzed and described.Then,based on regional structural setting,mud logging and logging data,the buried-hill reservoirs in this area were analyzed from the aspects of petrological characteristics,reservoir space types and physical properties,the inherent factors influencing the development of the reservoirs were discussed,and distribution laws of the reservoirs were investigated.And the following research results were obtained.First,the deep buried-hill reservoirs of this belt are a pan-buried hill reservoir system composed of the Palaeocene-Eocene Kongdian Fm glutenite in the upper part and the Archean buried-hill metamorphic granite in the lower part.A multi-layer reservoir structure of glutenite pore zone,weathering crust dissolution fracture zone and inner fracture zone is formed.These reservoirs are complex in genesis and diverse in type.Second,the Archean buried-hill metamorphic granite reservoir can be vertically divided into weathering crust,inner fracture zone and tight zone,and it presents the dual characteristics of porous and fractured media.Third,the buried-hill weathering crust is mainly affected by strong dissolution and leaching superimposed with fracturing,forming fractured-porous reservoir space.The reservoir of inner fracture zone is mainly controlled by the superimposition of three-phrase fractures,which forms the main development period of buried-hill fractures since the Yanshanian.Fourth,the glutenite of Kongdian Fm is a typical sieve deposit and it is mainly controlled by the late dissolution.Fifth,migmatization and supercritical fluid cryptoexplosion play a constructive role in the development of the reservoirs.In conclusion,the understanding of buried-hill glutenite and metamorphic reservoir system developed in this belt is conductive to determining the target and direction of next oil and gas exploration in this area.展开更多
JIANGNAN or regions south of the Yangtze River’s lower reaches, is an area with green hills and limpid waters. It has long been the epitome of natural beauty and fertility. Waterways are the main means of transportat...JIANGNAN or regions south of the Yangtze River’s lower reaches, is an area with green hills and limpid waters. It has long been the epitome of natural beauty and fertility. Waterways are the main means of transportation here as the land is divided by canals into a checkerboard. Under these natural conditions, locals designed and built their houses in a unique way, the design of which gave rise to the Suzhou traditional folk house architectural style. The houses are usually not wide and have a deep interior. The layout and scale of each house varies, depending on the wealth of its owner. When seen from a distance, the cluster of houses presents an irregular beauty densely decorating the small areas of land in the region.展开更多
CONSTRUCTION of Pilot Free Trade Zones(PFTZs)is a strategic measure of China’s reform and opening-up policy.Since the 18th National Congress of the Communist Party of China(CPC),it has taken the policy’s effectivene...CONSTRUCTION of Pilot Free Trade Zones(PFTZs)is a strategic measure of China’s reform and opening-up policy.Since the 18th National Congress of the Communist Party of China(CPC),it has taken the policy’s effectiveness to new heights.展开更多
A caricature exhibition on Chinese philosopher Laozi was held in Cairo on July 8, helping promote Chinese culture in Egypt and boost mutual cultural exchanges. The exhibition displayed more than 30 works by 40 artists...A caricature exhibition on Chinese philosopher Laozi was held in Cairo on July 8, helping promote Chinese culture in Egypt and boost mutual cultural exchanges. The exhibition displayed more than 30 works by 40 artists from 18 countries including China, Egypt, Spain, and Brazil. These paintings reflect the admiration and love of people from arround the world for Laozi’s philosophy.展开更多
POVERTY is still a major issue plaguing the modern world. In the 65 countries including China along the Belt and Road route, only 18 are high-income countries, with the per capita GDP reaching US $27,000. There are 22...POVERTY is still a major issue plaguing the modern world. In the 65 countries including China along the Belt and Road route, only 18 are high-income countries, with the per capita GDP reaching US $27,000. There are 22 countries in the upper-middle-income bracket as the average per capita GDP in these countries stands at US $7,000. The number of lower-middle-income nations is 23, having an average per capita GDP less than US $2,500. The remaining two, Afghanistan and Nepal, have their GDP per capita share of US $1,000.展开更多
基金supported by the National Natural Science Foundation of China,China(Nos.42102176&42030808)the SINOPEC Ministry of Science and Technology Project,China(No.P24189).
文摘Abnormally low pressure commonly develops in petroliferous basins.It is closely associated with hydrocarbon distribution and can hinder safe drilling operations.Potentiometric surface is one of the causes of abnormally low pressure,but the relationship between such surface and abnormal pressure has not attracted much research attention.In this paper,a method is proposed for quantifying the potentiometric surface of the tight oil reservoir of the Upper Triassic Yanchang Formation in the Zhenjing area,southern Ordos Basin,China.This method involves screening pressure data that reflect real pore pressure conditions underground and analyzing the formation sealing conditions in the reservoir based on fracture development and the chemical characteristics of the formation water.The relationship between the potentiometric surface and the abnormally low pressure observed in the study area is discussed.The results show that the pressure coefficient of the Yanchang Formation in the Zhenjing area is 0.85e1.02,with an average of 0.93,indicating a state between abnormally low pressure and normal pressure.The Yanchang Formation has complex sealing conditions,with favorable overall sealing and a locally open hydrodynamic environment controlled by sand body connectivity and fault activity.We proposed a method to calculate the potentiometric surface using the measured pressure data with a pressure coefficient close to 1.The potentiometric surface is 1040e1200 m,with a high value in the northwest and a low value in the southeast,and it is 0e350 m below the ground level.The pressure coefficient was calibrated with an average of 1,with the potentiometric surface used as the starting point,indicating that the low pressure coefficient may be caused by the potentiometric surface below the ground level.The results have theoretical implications for the analysis of formation pressure characteristics in areas or basins with comparable geological conditions,and practical implications for the analysis and development of oil and gas.
基金supported by the National Natural Science Foundation of China(No.24A20592).
文摘The Cambrian Qiongzhusi Formation in the Sichuan Basin harbors significant potential for shale gas harvesting.However,systematic disparities in mineral composition and reservoir architecture have been observed between intra-and extra-trough reservoirs within the Deyang-Anyue Rift Trough.These variations were primarily determined by divergences in the sedimentary environments developed during the evolution of the rift trough,which were a main factor in fostering the heterogeneous distribution of shale gas enrichment found today.However,the genetic mechanisms that govern reservoir heterogeneity across distinct structural domains(intra-trough,trough margin,and extra-trough)remain poorly understood,particularly regarding the coupling relationships between depositional environments,reservoir characteristics,and gas-bearing properties.This study adopts a multidisciplinary approach to investigating this issue that integrates core analysis,well-log interpretations,and geochemical data.Through systematic comparisons conducted using X-ray diffraction mineralogy,organic carbon quantification,and spontaneous imbibition experiments,we characterize the mineral assemblages,organic geochemical signatures,and pore structures found across the three structural domains of the Deyang-Anyue Rift Trough.The key findings are as follows:(1)The depositional environment is the main influence on reservoir distribution and organic matter enrichment,with intra-trough shales exhibiting a higher abundance of organic matter than their trough-margin and extra-trough counterparts.(2)Enhanced brittleness in intra-trough zones correlates with the predominance of biogenic silica therein.(3)Synergistic organic-inorganic interactions govern pore system development.(4)Gas-bearing capacity is jointly determined by effective porosity and organic matter content.These findings establish the rift trough as a preferential exploration target,providing critical geological guidance for optimizing shale gas exploration strategies in the Cambrian Qiongzhusi Formation.
基金supported by the Nation Natural Science Foundation of China Youth Project(No.42107196).
文摘Enzyme Induced Carbonate Precipitation(EICP)has been extensively investigated as a promising approach to improve engineering properties of soil,while Eggshell Powder(ESP)is an agricultural waste that effectively fills soil pores.The ESP provides abundant nucleation at sites for the EICP process,further promoting the effective precipitation of calcium carbonate.The research presented in this paper investigated the Soil Water Characteristic Curves(SWCC),permeability coefficient,and microstructure of expansive soil before and after EICP and EICP+ESP modification.A series of laboratory experiments were conducted,including soil water characteristic tests,permeability tests and Scanning Electron Microscopy(SEM).The results proved that the addition of EICP and EICP+ESP into natural expansive soil resulted in a gradual decline in air entry value,residual water content,and permeability coefficient,indicating an increase in water retention capacity and a decrease in permeability.Furthermore,with the intrusion of EICP and EICP+ESP,the contact between particles becomes smoother,and the soil pores become more equally distributed.Ultimately,there was an enhancement in water retention capacity of the natural expansive soil.This study emphasizes the synergistic potential of combining EICP and EICP+ESP as stabilizing additives to enhance the water retention capacity of expansive soil.Moreover,the reuse of ESP provides a sustainable solution for the resource utilization of agricultural waste and the improvement of expansive soil using bio-inspired methods.
基金supported by the National Research Foundation of Korea(NRF)grants funded by the Korea government(MSIT)(Nos.RS-2024–00351052 and RS-2024–00450561).
文摘This study compares the microstructural evolution,dynamic recrystallization(DRX)behavior,tensile properties,and age-hardenability between the newly developed high-speed-extrudable BA56 alloy and those of the widely recognized AZ31 alloy in industry.Unlike the AZ31 alloy,which retains partially unrecrystallized grains,the high-speed-extruded BA56 alloy demonstrates a coarser but entirely recrystallized and more homogeneous microstructure.The fine-grained structure and abundant Mg_(3)Bi_(2) particles in the BA56 extrusion billet significantly enhance its DRX behavior,thus enabling rapid and complete recrystallization during extrusion.The BA56 alloy contains band-like fragmented Mg_(3)Bi_(2) particles and numerous fine Mg_(3)Bi_(2) particles distributed throughout the material,in contrast to the sparse Al_(8)Mn_(5) particles in the AZ31 alloy.These features contribute to superior mechanical properties of the BA56 alloy,which achieves tensile yield and ultimate tensile strengths of 205 and 292 MPa,respectively,compared to 196 and 270 MPa for the AZ31 alloy.The superior strength of the BA56 alloy,even with its coarser grain size,can be explained by its elevated Hall-Petch constant and the strengthening contribution from the fine Mg_(3)Bi_(2) particles.Additionally,the BA56 alloy demonstrates significant age-hardenability,achieving a 22%enhancement in hardness following T5 aging,attributed to the precipitation of nanoscale Mg_(3)Bi_(2) and Mg_(17)Al_(12) phases.By contrast,the AZ31 alloy shows minimal hardening due to the absence of precipitate formation during aging.These findings suggest that the BA56 alloy is a promising candidate for the production of extruded Mg components requiring a combination of high productivity,superior mechanical performance,and wide-ranging process adaptability.
基金supported by the National Natural Science Foundation of China,China(No.52474088).
文摘Liquid hydrogen has attracted much attention due to its high energy storage density and suitability for long-distance transportation.An efficient hydrogen liquefaction process is the key to obtaining liquid hydrogen.In an effort to determine the parameter optimization of the hydrogen liquefaction process,this paper employed process simulation software Aspen HYSYS to simulate the hydrogen liquefaction process.By establishing a dynamic model of the unit module,this study carried out dynamic simulation optimization based on the steady-state process and process parameters of the hydrogen liquefaction process and analyzed the dynamic characteristics of the process.Based on the pressure drop characteristic experiment,an equation for the pressure drop in the heat exchanger was proposed.The heat transfer of hydrogen conversion was simulated and analyzed,and its accuracy was verified by comparison with the literature.The dynamic simulation of a plate-fin heat exchanger was carried out by coupling heat transfer simulation and the pressure drop experiment.The results show that the increase in inlet temperature(5℃and 10℃)leads to an increase in specific energy consumption(0.65%and 1.29%,respectively)and a decrease in hydrogen liquefaction rate(0.63%and 2.88%,respectively).When the inlet pressure decreases by 28.57%,the hydrogen temperature of the whole liquefaction process decreases and the specific energy consumption increases by 52.94%.The research results are of great significance for improving the operating efficiency of the refrigeration cycle and guiding the actual liquid hydrogen production.
基金supported by the National Natural Science Foundation of China(41927801)the Major Special Project of Yunnan Province(202302AF080001)the Key Research and Development Program of Yunnan Province(202303AA080006).
文摘China is tectonically composed of a series of plates and orogenic belts and has been influenced by the Pacific and Indian plates since the Late Paleozoic,forming a regular distribution of Mesozoic and Cenozoic granites.As an important source of geothermal energy,granite is thefive elements of geothermal enrichment:geothermal sources;geothermal reservoirs;heat transmission;heat caprock;and heat preservation and it is possible to classify the types of geothermal resources in China according to their distribution in combination with neotectonic movements.China's geothermal energy can be divided into hydrothermal and hot dry rock types in basins and orogenic belts,respectively.Geothermal resources can be divided into hydrothermal,rock,magma,and hybrid geothermal types according to the heat carrier type.Basin geothermal resources are dominated by hydrothermal types,while geothermal energy in orogenic belts with granite includes both hydrothermal and hot dry rock types.Geothermal resources in China can be divided into 6 distinct geothermal regions and 13 subregions,of which the Southwest and Southeast China regions and the Qaidam-Qilian and Jiaoliao subregions in North China with Mesozoic and Cenozoic granites are the most favorable areas for high-temperature hydrothermal and hot dry rock sources.China has complex geological conditions,diverse types of geothermal resources,and broad prospects for development and utilization.Having performed extensive shallow hydrothermal geothermal development and utilization and completed various power generation tests,China's geothermal development and utilization is in a critical stage of transition from the direct utilization of shallow hydrothermal resources to high-temperature geothermal or hot dry rock power generation in middle and deep layers.Basic theoretical research,key technology breakthroughs,and policy incentives are the main issues that need to be addressed in the geothermal industry.
文摘The diet of Bryconalestes tholloni from Mafoubou River, Sous-affluent of Niari River was studied by examining the stomach contents of 75 specimens captured using the cast nets. This study is the first realized on the trophic ecology of a fish species of Niari Basin. Three stations were sampled monthly from July to December 2019. The diet was analyzed according to hydrological season and fish size. The vacuity coefficient is 27%, feeding habits of Bryconalestes tholloni were analyzed using the preponderance index which combines the occurrence percentage and the weight percentage. Bryconalestes tholloni is insectivorous (Ip = 95.54%) and becomes omnivorus to predominantly frugivorous, the preponderance index of fruits is equal to 93.6% in large individuals. There is no variation in diet according to the season. These results constitute a first database on the feeding habits Niari Basin fishes.
文摘This study uses the PΔV term in the ideal gas equation PΔV = nRΔT to show how the 1-degree temperature increase that expands the occupied volume of a gas by ΔV against constant pressure P also causes the system to increase its entropy by ΔS. As the volume available to a gas sample increases, the locations for disordered molecular relocation also increase. The causal agent linking a volume increase ΔV and an entropy increase ΔS is absolute temperature T measured in kelvin units. Since a volume increase is empirically observable while an increase in randomized molecular disorder is not, a per-kelvin increase in gas volume provides a method for estimating entropy increase. Both volume and entropy are extensive variables dependent upon the number of molecules in the system. Both are deemed to be at their absolute minima at the absolute zero of temperature. This study provides an insight into how a per-kelvin temperature increase causes both a linear increase in gas volume and a linear increase in gas entropy. When people talk about randomized disorder without specifying absolute temperature and molecule-count for the system, they are discussing a concept other than thermodynamic entropy.
文摘THE China-Egypt Teda Suez Economic and Trade Cooperation Zone, or simply Teda Cooperation Zone, is located in Sokhna District of Suez Province, more than 120 kilometers away from Cairo, the capital of Egypt. It is among the second batch of state-level overseas economic and trade cooperation zones approved by the Chinese government. Signboards bearing the phrase “A sign of development” can be seen everywhere in the park, marking the original intention of setting up this economic and trade cooperation zone.
文摘China’s interests and future are closely linked to those of the world,and it wishes to work with all countries for common development and a community with a shared future for mankind,Chinese Vice President Wang Qishan said at the 2019 World Economic Forum(WEF)in Davos,Switzerland on January 23.
文摘ECOLOGICAL civilization is a new form of civilization that is based on industrial civilization and capitalizes on its strengths. It represents the material and spiritual achievements humankind has made by following the principles of maintaining harmony between man, nature, and society. It also reflects the civility and progress of a society. China has incorporated the building of ecological civilization into a five-sphere integrated plan to promote coordinated economic, political, cultural, social, and ecological advancement.
基金supported by the National Major Science and Technology Project“Comprehensive Study on Buried-Hill Reservoir-Forming in the Bohai Sea and Favorable Exploration Direction”(No.:2016ZX05024-003-010)the Scientific Research Project of CNOOC“Petroleum Geological Characteristics,Forming Mechanism of Typical Oil&Gas Reservoir and Prediction of Prospects of the Buried Hill in the Bohai Sea Area”(No.:CCL2014TJXZSS0870).
文摘The BZ19-6 deep buried-hill structural belt in the southwest of Bozhong Sag,Bohai Bay Basin,is a newly discovered super-giant oil and gas bearing area.The study on its reservoirs is still in the early stage,and the characteristics and control factors of reservoir development are not understood deeply.In this paper,cores,sidewall cores,rock sections were analyzed and described.Then,based on regional structural setting,mud logging and logging data,the buried-hill reservoirs in this area were analyzed from the aspects of petrological characteristics,reservoir space types and physical properties,the inherent factors influencing the development of the reservoirs were discussed,and distribution laws of the reservoirs were investigated.And the following research results were obtained.First,the deep buried-hill reservoirs of this belt are a pan-buried hill reservoir system composed of the Palaeocene-Eocene Kongdian Fm glutenite in the upper part and the Archean buried-hill metamorphic granite in the lower part.A multi-layer reservoir structure of glutenite pore zone,weathering crust dissolution fracture zone and inner fracture zone is formed.These reservoirs are complex in genesis and diverse in type.Second,the Archean buried-hill metamorphic granite reservoir can be vertically divided into weathering crust,inner fracture zone and tight zone,and it presents the dual characteristics of porous and fractured media.Third,the buried-hill weathering crust is mainly affected by strong dissolution and leaching superimposed with fracturing,forming fractured-porous reservoir space.The reservoir of inner fracture zone is mainly controlled by the superimposition of three-phrase fractures,which forms the main development period of buried-hill fractures since the Yanshanian.Fourth,the glutenite of Kongdian Fm is a typical sieve deposit and it is mainly controlled by the late dissolution.Fifth,migmatization and supercritical fluid cryptoexplosion play a constructive role in the development of the reservoirs.In conclusion,the understanding of buried-hill glutenite and metamorphic reservoir system developed in this belt is conductive to determining the target and direction of next oil and gas exploration in this area.
文摘JIANGNAN or regions south of the Yangtze River’s lower reaches, is an area with green hills and limpid waters. It has long been the epitome of natural beauty and fertility. Waterways are the main means of transportation here as the land is divided by canals into a checkerboard. Under these natural conditions, locals designed and built their houses in a unique way, the design of which gave rise to the Suzhou traditional folk house architectural style. The houses are usually not wide and have a deep interior. The layout and scale of each house varies, depending on the wealth of its owner. When seen from a distance, the cluster of houses presents an irregular beauty densely decorating the small areas of land in the region.
文摘CONSTRUCTION of Pilot Free Trade Zones(PFTZs)is a strategic measure of China’s reform and opening-up policy.Since the 18th National Congress of the Communist Party of China(CPC),it has taken the policy’s effectiveness to new heights.
文摘A caricature exhibition on Chinese philosopher Laozi was held in Cairo on July 8, helping promote Chinese culture in Egypt and boost mutual cultural exchanges. The exhibition displayed more than 30 works by 40 artists from 18 countries including China, Egypt, Spain, and Brazil. These paintings reflect the admiration and love of people from arround the world for Laozi’s philosophy.
文摘POVERTY is still a major issue plaguing the modern world. In the 65 countries including China along the Belt and Road route, only 18 are high-income countries, with the per capita GDP reaching US $27,000. There are 22 countries in the upper-middle-income bracket as the average per capita GDP in these countries stands at US $7,000. The number of lower-middle-income nations is 23, having an average per capita GDP less than US $2,500. The remaining two, Afghanistan and Nepal, have their GDP per capita share of US $1,000.
