As essential elements of the graphite reflector in thorium-based molten salt reactor,dowel–brick structures are used to withstand complex working loads in the reactor core and their failure may lead to serious damage...As essential elements of the graphite reflector in thorium-based molten salt reactor,dowel–brick structures are used to withstand complex working loads in the reactor core and their failure may lead to serious damage of the graphite reactor core.It is crucial to investigate the stress behavior of dowel–brick structures for safe operation of the graphite reactor.In this study,three groups of finite element analyses and a strain test were carried out to investigate how the geometric parameters of the dowels affect the stress behavior of the dowel–brick structure.The numerical results indicate that the stress behavior of a dowel–brick structure is significantly affected by the diameter,length,and aspect ratio of the dowels.The maximum stress in the lower and upper bricks decreases with an increase in the dowel length.The location of maximum stress on both lower and upper bricks shifts from the root of the socket to the edge of that socket beside the contact region,as the length of the dowel increases.The shift of the maximum stress location occurs earlier for the upper bricks than for the lower bricks.The results of strain tests show good agreement with those of numerical analyses.展开更多
The microstructure and properties of phosphate bonded Cr2O3 - -Al2O3 - ZrO2 specimens fired in air or coke bed were investigated firstly. Then property change of the Cr2 O3 - Al2 O3 - ZrO2 bricks after secondary treat...The microstructure and properties of phosphate bonded Cr2O3 - -Al2O3 - ZrO2 specimens fired in air or coke bed were investigated firstly. Then property change of the Cr2 O3 - Al2 O3 - ZrO2 bricks after secondary treat- ment in simulation environment was studied. Finally, corrosion resistances of the Cr2 O3 - Al2 O3 - ZrO2 bricks in air and simulation environment were compared; and microstructure of on-site used Cr2O3 - Al2O3 - ZrO2 bricks in slagging gasifiers was analyzed. The results show that the atmosphere has significant effect on the mi- crostructure and properties of the phosphate bonded Cr2O3 -Al2O3 -ZrO2 bricks. As the specimens are fired in air, the phosphate forms a composite solid solution with Cr2 O3 and Al2 O3, therefore, strength of the speci- mens is enhanced. For specimens fired in coke bed, a certain amount of gases are generated owing to the re- duction of phosphate and part of Cr2 O3, which results in the increasing number and size of the pores, bad interfa- cial bonding between Cr2O3 aggregates and matrix as well as low strength of the specimens. During service process in reducing atmosphere, the phosphate binder and part of Cr2O3 in edge of the specimens are also re- duced, leading to significant increase of number and size of the pores in the edge of the specimens; as a result, inreducing atmosphere, the specimens show much worse corrosion resistance than in air.展开更多
The resin-sand mixture was proposed to be used as the surface course,and cement permeable concrete was used as the base course;such two kinds of materials were combined to prepare water-permeable brick with a composit...The resin-sand mixture was proposed to be used as the surface course,and cement permeable concrete was used as the base course;such two kinds of materials were combined to prepare water-permeable brick with a composite structure.The compressive strength,flexural strength,and permeability were studied by using adjusting the contents of carbon fiber,quartz powder,cement,sand,and surfactant.The study shows that the hydrophilicity of the resin-sand mixture can be improved after any amount of resin is replaced by quartz powder;by using the surfactant,the interface energy of the particles can be reduced so that the water permeability of the surface course can be promoted effectively.However,the mechanical properties of the surface course were negatively affected by the surfactant.With the optimal process consideration in the experiments,the properties about compressive strength,flexural strength,and permeability of the composite permeable brick can meet the requirements of the specifications of resin-sand based water permeable brick JGT 376-2012(compressive strength was higher than 35 MPa,the flexural strength exceeded 5.19 MPa,and the average permeability coefficient was higher than 2.3×10^(-2)cm/s).There are no obvious pores on the surface course and only water molecules can pass through it,therefore,the surface of the permeable brick cannot be blocked up by solid substances,and the permeability of such permeable brick can be improved effectively in this way.展开更多
Conversion-type fluoride cathode can provide considerable energy density for Li batteries,however its scalable and facile synthesis strategies are still lacking.Here,a novel Fe-based deep eutectic solvent composed of ...Conversion-type fluoride cathode can provide considerable energy density for Li batteries,however its scalable and facile synthesis strategies are still lacking.Here,a novel Fe-based deep eutectic solvent composed of nitrite and methylsulfonylmethane is proposed as both the reaction medium and precursor to synthesize O-doped FeF3porous bricks.This method is cheaper,safe,mildly operable,environmentally friendly and recyclable for non-fluorinated metal cations.The homogenization of charge and mass transport in cathode network effectively mitigates the volume extrusion and electrode coarsening even for the micro-sized monolithic particles.The Co-solvation modulated fluoride cathode delivers high reversible capacity in a wide temperature range(486 and 235 mA h g^(-1)at 25℃ and-20℃ respectively),excellent rate performance(312 mA h g^(-1)at 1000 mA g^(-1)),corresponding to an energy density as high as672.1 W h kg^(-1)under a power density of 2154.3 W kg^(-1).The successful operation of fluoride pouchcell with a capacity exceeding 450 mA h g^(-1)(even under thin Li foil and lean electrolyte conditions) indicates its potentiality of commercial application.展开更多
One new coordination polymer with the chemical formula [CoCu2L2·K2·1.5C2H5OH]n（H4L = 2-hydroxy-3-[（E）-（{3-[（2-hydroxybenzoyl）amino]propyl}imino）methyl] benzoic acid） has been synthesized based on the...One new coordination polymer with the chemical formula [CoCu2L2·K2·1.5C2H5OH]n（H4L = 2-hydroxy-3-[（E）-（{3-[（2-hydroxybenzoyl）amino]propyl}imino）methyl] benzoic acid） has been synthesized based on the slow diffusion method,and characterized by IR spectroscopy,thermalgravimetric and X-ray diffraction analysis.It crystallizes in the monoclinic system,space group P21/n with a = 11.98860（10）,b = 24.4279（3）,c = 14.9008（2） ,β = 104.7490（10）°,V = 4220.01（8） 3,Z = 2,Mr = 1009.94,Dc = 1.590 g/cm3,F（000） = 2056,μ（MoKα） = 1.649 mm-1,the final R = 0.0411 and wR = 0.1178 for 5920 observed reflections with I 2σ（I）.The compound possesses a 2D brick wall structure constructed from trinuclear units.展开更多
作为西南山区最为频发的地质灾害之一,滑坡对山区中大量存在的砖混房屋造成严重影响,尤其农村山区中受灾最为严重,给人民群众生产生活造成巨大安全隐患.研究滑坡引起的上部砖混结构变形特征,对科学指导房屋设计防护及灾后监测点布置具...作为西南山区最为频发的地质灾害之一,滑坡对山区中大量存在的砖混房屋造成严重影响,尤其农村山区中受灾最为严重,给人民群众生产生活造成巨大安全隐患.研究滑坡引起的上部砖混结构变形特征,对科学指导房屋设计防护及灾后监测点布置具有重要现实意义.本文以酉阳高园子滑坡为例,通过现场调查和裂缝参数拟合研究了滑坡区砖混结构变形破坏特征.同时基于PFC3D,构建了有限体积-离散元(Finite Volume Method-Discrete Element Method,FVM-DEM)滑坡-房屋单向耦合模型,模拟并分析了在不同工况下滑坡动态发育过程,进一步揭示了房屋裂缝产生及演化过程.结果表明:相比于普通无柱砖混结构,底框结构抵抗滑坡诱发变形破坏的能力更强,并且处于前后缘段的房屋相对中段房屋更易出现损伤破坏;房屋的长宽比不宜过小,布置房屋长边走向平行斜坡走向有利于减少滑坡对房屋造成的破坏.本文总结了在滑坡作用下,上部砖混结构的变形特征和裂缝开展规律,可为农村山区砖混结构设计和布置提供参考.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA02010000).
文摘As essential elements of the graphite reflector in thorium-based molten salt reactor,dowel–brick structures are used to withstand complex working loads in the reactor core and their failure may lead to serious damage of the graphite reactor core.It is crucial to investigate the stress behavior of dowel–brick structures for safe operation of the graphite reactor.In this study,three groups of finite element analyses and a strain test were carried out to investigate how the geometric parameters of the dowels affect the stress behavior of the dowel–brick structure.The numerical results indicate that the stress behavior of a dowel–brick structure is significantly affected by the diameter,length,and aspect ratio of the dowels.The maximum stress in the lower and upper bricks decreases with an increase in the dowel length.The location of maximum stress on both lower and upper bricks shifts from the root of the socket to the edge of that socket beside the contact region,as the length of the dowel increases.The shift of the maximum stress location occurs earlier for the upper bricks than for the lower bricks.The results of strain tests show good agreement with those of numerical analyses.
文摘The microstructure and properties of phosphate bonded Cr2O3 - -Al2O3 - ZrO2 specimens fired in air or coke bed were investigated firstly. Then property change of the Cr2 O3 - Al2 O3 - ZrO2 bricks after secondary treat- ment in simulation environment was studied. Finally, corrosion resistances of the Cr2 O3 - Al2 O3 - ZrO2 bricks in air and simulation environment were compared; and microstructure of on-site used Cr2O3 - Al2O3 - ZrO2 bricks in slagging gasifiers was analyzed. The results show that the atmosphere has significant effect on the mi- crostructure and properties of the phosphate bonded Cr2O3 -Al2O3 -ZrO2 bricks. As the specimens are fired in air, the phosphate forms a composite solid solution with Cr2 O3 and Al2 O3, therefore, strength of the speci- mens is enhanced. For specimens fired in coke bed, a certain amount of gases are generated owing to the re- duction of phosphate and part of Cr2 O3, which results in the increasing number and size of the pores, bad interfa- cial bonding between Cr2O3 aggregates and matrix as well as low strength of the specimens. During service process in reducing atmosphere, the phosphate binder and part of Cr2O3 in edge of the specimens are also re- duced, leading to significant increase of number and size of the pores in the edge of the specimens; as a result, inreducing atmosphere, the specimens show much worse corrosion resistance than in air.
基金Funded by the Natural Science Foundation of Fujian Province(No.2016J01241)the National Natural Science Foundation of China(No.51608212)the Education Department of Fujian Province(No.JA14024)。
文摘The resin-sand mixture was proposed to be used as the surface course,and cement permeable concrete was used as the base course;such two kinds of materials were combined to prepare water-permeable brick with a composite structure.The compressive strength,flexural strength,and permeability were studied by using adjusting the contents of carbon fiber,quartz powder,cement,sand,and surfactant.The study shows that the hydrophilicity of the resin-sand mixture can be improved after any amount of resin is replaced by quartz powder;by using the surfactant,the interface energy of the particles can be reduced so that the water permeability of the surface course can be promoted effectively.However,the mechanical properties of the surface course were negatively affected by the surfactant.With the optimal process consideration in the experiments,the properties about compressive strength,flexural strength,and permeability of the composite permeable brick can meet the requirements of the specifications of resin-sand based water permeable brick JGT 376-2012(compressive strength was higher than 35 MPa,the flexural strength exceeded 5.19 MPa,and the average permeability coefficient was higher than 2.3×10^(-2)cm/s).There are no obvious pores on the surface course and only water molecules can pass through it,therefore,the surface of the permeable brick cannot be blocked up by solid substances,and the permeability of such permeable brick can be improved effectively in this way.
基金supported by the National Natural Science Foundation of China(51772313,21975276 and 52102329)the Shanghai Science and Technology Committee(20520710800)support by the Program of Shanghai Academic Research Leader(21XD1424400)。
文摘Conversion-type fluoride cathode can provide considerable energy density for Li batteries,however its scalable and facile synthesis strategies are still lacking.Here,a novel Fe-based deep eutectic solvent composed of nitrite and methylsulfonylmethane is proposed as both the reaction medium and precursor to synthesize O-doped FeF3porous bricks.This method is cheaper,safe,mildly operable,environmentally friendly and recyclable for non-fluorinated metal cations.The homogenization of charge and mass transport in cathode network effectively mitigates the volume extrusion and electrode coarsening even for the micro-sized monolithic particles.The Co-solvation modulated fluoride cathode delivers high reversible capacity in a wide temperature range(486 and 235 mA h g^(-1)at 25℃ and-20℃ respectively),excellent rate performance(312 mA h g^(-1)at 1000 mA g^(-1)),corresponding to an energy density as high as672.1 W h kg^(-1)under a power density of 2154.3 W kg^(-1).The successful operation of fluoride pouchcell with a capacity exceeding 450 mA h g^(-1)(even under thin Li foil and lean electrolyte conditions) indicates its potentiality of commercial application.
基金Supported by the Technology Chamber of Henan Province (092300410031)the Education Chamber of Henan Province (2009A150005)
文摘One new coordination polymer with the chemical formula [CoCu2L2·K2·1.5C2H5OH]n（H4L = 2-hydroxy-3-[（E）-（{3-[（2-hydroxybenzoyl）amino]propyl}imino）methyl] benzoic acid） has been synthesized based on the slow diffusion method,and characterized by IR spectroscopy,thermalgravimetric and X-ray diffraction analysis.It crystallizes in the monoclinic system,space group P21/n with a = 11.98860（10）,b = 24.4279（3）,c = 14.9008（2） ,β = 104.7490（10）°,V = 4220.01（8） 3,Z = 2,Mr = 1009.94,Dc = 1.590 g/cm3,F（000） = 2056,μ（MoKα） = 1.649 mm-1,the final R = 0.0411 and wR = 0.1178 for 5920 observed reflections with I 2σ（I）.The compound possesses a 2D brick wall structure constructed from trinuclear units.
文摘作为西南山区最为频发的地质灾害之一,滑坡对山区中大量存在的砖混房屋造成严重影响,尤其农村山区中受灾最为严重,给人民群众生产生活造成巨大安全隐患.研究滑坡引起的上部砖混结构变形特征,对科学指导房屋设计防护及灾后监测点布置具有重要现实意义.本文以酉阳高园子滑坡为例,通过现场调查和裂缝参数拟合研究了滑坡区砖混结构变形破坏特征.同时基于PFC3D,构建了有限体积-离散元(Finite Volume Method-Discrete Element Method,FVM-DEM)滑坡-房屋单向耦合模型,模拟并分析了在不同工况下滑坡动态发育过程,进一步揭示了房屋裂缝产生及演化过程.结果表明:相比于普通无柱砖混结构,底框结构抵抗滑坡诱发变形破坏的能力更强,并且处于前后缘段的房屋相对中段房屋更易出现损伤破坏;房屋的长宽比不宜过小,布置房屋长边走向平行斜坡走向有利于减少滑坡对房屋造成的破坏.本文总结了在滑坡作用下,上部砖混结构的变形特征和裂缝开展规律,可为农村山区砖混结构设计和布置提供参考.
