Magnetohydrodynamic （MHD） pressure drop in the Chinese Dual Functional Liquid Lithium-lead Test Blanket Module （DFLL-TBM） proposed for ITER is discussed in this paper. Electrical insulation between the coolant cha...Magnetohydrodynamic （MHD） pressure drop in the Chinese Dual Functional Liquid Lithium-lead Test Blanket Module （DFLL-TBM） proposed for ITER is discussed in this paper. Electrical insulation between the coolant channel surfaces and the liquid metal is required to reduce the MHD pressure drop to a manageable level. Insulation can be provided by a thin insulating coating, such as Al2O3, which can also serve as a tritium barrier layer, at the channel surfaces in contact with LiPb. The coating＇s effectiveness for reducing the MHD pressure drop is analysed through three-dimensional numerical simulation. A MHD-based commercial computational fluid dynamic （CFD） software FLUENT is used to simulate the LiPb flow. The effect on the MHD pressure drop due to cracks or faults in the coating layer is also considered. The insulating performance requirement for the coating material in DFLL-TBM design is proposed according to the analysis.展开更多
While the enhancement of elastomer properties through nanofiller addition has been widely explored,developing high-performance elastomers for electrically insulating electromagnetic interference(EMI)shielding material...While the enhancement of elastomer properties through nanofiller addition has been widely explored,developing high-performance elastomers for electrically insulating electromagnetic interference(EMI)shielding materials using a simple approach remains crucial.In this study,high-performance composite silicone rubber(SR)elastomers were fabricated through a combination of straightforward physical mixing and chemical grafting approach.Specifically,the incorporation of components aluminum trioxide nanoparticles(n-Al_(2)O_(3))and reactive small molecule 2-isocyanoethyl acrylate(ICA)and 2-Amino-4-hydroxy-6-methylpyrimidine(UPY)into SR significantly improved both the mechanical strength and ther-mal resistance of the composites due to the synergistic effects of nanoparticles and hydrogen bonding.In addition,as flexible electronics become more complex and miniaturised,there is an increasing demand for stretchable electrically insulating EMI shielding materials.Liquid metal(LM)with extreme fluidity is ideal for the preparation of stretchable EMI shielding materials.By introducing LM,we prepared a stretchable electrically insulating EMI shielding material with a sandwich structure using a simple mechanical sintering and lamination process,and the EMI shielding properties of the material remained stable before and after stretching.The modified insulating layer has excellent elasticity and thermal stability,which en-sures the normal use of the composite EMI shielding material under high temperatures and mechanical deformation conditions.This research provides valuable insights into the development of shielding materials with high-performance electrical insulation and strain-invariant EMI shielding behavior.展开更多
Pressure induced insulator to metal transition followed by the appearance of superconductivity has been observed recently in inorganic quantum spin liquid candidate NaYbSe_(2).In this paper,we study the properties of ...Pressure induced insulator to metal transition followed by the appearance of superconductivity has been observed recently in inorganic quantum spin liquid candidate NaYbSe_(2).In this paper,we study the properties of isostructural compound NaYbS_(2)under pressure.It is found that the resistance of Na YbS_(2)single crystal exhibits an insulating state below 82.9 GPa,but with a drop of more than six orders of magnitude at room temperature.Then a minimum of resistance is observed at about 100.1 GPa and it moves to lower temperature with further compression.Finally,a metallic state in the whole temperature range is observed at about 130.3 GPa accompanied by a non-Fermi liquid behavior below 100 K.The insulator to metal transition,non-monotonic resistance feature and non-Fermi liquid behavior of NaYbS_(2)under pressure are similar to those of NaYbSe_(2),suggesting that these phenomena might be the universal properties in NaLnCh_(2)(Ln=rare earth,Ch=O,S,Se)system.展开更多
This paper describes an experimental and theoretical study on an extraction phenomenon of liquids occurring at an air gap between the liquid surface and the electrode by applying a direct current (DC) or low-frequency...This paper describes an experimental and theoretical study on an extraction phenomenon of liquids occurring at an air gap between the liquid surface and the electrode by applying a direct current (DC) or low-frequency alternating current (AC) voltage. Three liquids with a different physical property;2,3-dihydrodecafluoropenten, palm fatty acid ester oil and crude rapeseed oil are used as working liquids. The electrode configuration is the sphere or plane (high voltage electrode) to grounded plane electrode. The grounded plane electrode is fixed to the bottom of the test vessel with working liquid and the high voltage electrode is installed in an air above the liquid surface against the grounded plane electrode. The liquid surface swells towards the high voltage electrode by the increase of voltage and the liquid is extracted in a short time, thereafter the air gap between the liquid surface and the high voltage electrode is bridged at a thick liquid column. Such the liquid behavior displays unique features with voltage polarity effect for each working liquid. The relationship between the applied voltage, current variation, height of swollen liquid, force pulling liquid and dynamic feature of liquid is examined experimentally. The liquid behavior is considered theoretically based on experimental observations.展开更多
Insulating liquid plays an important role for the life span of the transformer.Petroleum-based mineral oil has become dominant insulating liquid of transformer for more than a century for its excellent dielectric and ...Insulating liquid plays an important role for the life span of the transformer.Petroleum-based mineral oil has become dominant insulating liquid of transformer for more than a century for its excellent dielectric and cooling properties.However,the usage of petroleum-based mineral oil,derived from a nonrenewable energy source,has affected the environment for its nonbiodegradability property.Therefore,researchers direct their attention to renewable and biodegradable alternatives.Palm fatty acid ester,coconut oil,sunflower oil,etc.are considered as alternatives to replace mineral oil as transformer insulation liquid.This paper gives an extensive review of different liquid insulating materials used in a transformer.Characterization of different liquids as an insulating material has been discussed.An attempt has been made to classify different insulating liquids-based on different properties.展开更多
基金Anhui Provincial Natural Science Foundation of China(No.070413085)Anhui Education Department Natural Science Foundation of China(No.2006KJ264)
文摘Magnetohydrodynamic （MHD） pressure drop in the Chinese Dual Functional Liquid Lithium-lead Test Blanket Module （DFLL-TBM） proposed for ITER is discussed in this paper. Electrical insulation between the coolant channel surfaces and the liquid metal is required to reduce the MHD pressure drop to a manageable level. Insulation can be provided by a thin insulating coating, such as Al2O3, which can also serve as a tritium barrier layer, at the channel surfaces in contact with LiPb. The coating＇s effectiveness for reducing the MHD pressure drop is analysed through three-dimensional numerical simulation. A MHD-based commercial computational fluid dynamic （CFD） software FLUENT is used to simulate the LiPb flow. The effect on the MHD pressure drop due to cracks or faults in the coating layer is also considered. The insulating performance requirement for the coating material in DFLL-TBM design is proposed according to the analysis.
基金the financial support from the Director’s Fund of the Hefei Institute of Materials Research,Chinese Academy of Sciences(Nos.YZJJQY202405 and YZJJ2024QN36).
文摘While the enhancement of elastomer properties through nanofiller addition has been widely explored,developing high-performance elastomers for electrically insulating electromagnetic interference(EMI)shielding materials using a simple approach remains crucial.In this study,high-performance composite silicone rubber(SR)elastomers were fabricated through a combination of straightforward physical mixing and chemical grafting approach.Specifically,the incorporation of components aluminum trioxide nanoparticles(n-Al_(2)O_(3))and reactive small molecule 2-isocyanoethyl acrylate(ICA)and 2-Amino-4-hydroxy-6-methylpyrimidine(UPY)into SR significantly improved both the mechanical strength and ther-mal resistance of the composites due to the synergistic effects of nanoparticles and hydrogen bonding.In addition,as flexible electronics become more complex and miniaturised,there is an increasing demand for stretchable electrically insulating EMI shielding materials.Liquid metal(LM)with extreme fluidity is ideal for the preparation of stretchable EMI shielding materials.By introducing LM,we prepared a stretchable electrically insulating EMI shielding material with a sandwich structure using a simple mechanical sintering and lamination process,and the EMI shielding properties of the material remained stable before and after stretching.The modified insulating layer has excellent elasticity and thermal stability,which en-sures the normal use of the composite EMI shielding material under high temperatures and mechanical deformation conditions.This research provides valuable insights into the development of shielding materials with high-performance electrical insulation and strain-invariant EMI shielding behavior.
基金the National Key Research and Development Program of China(Grant Nos.2018YFA0305700,2018YFE0202600,and 2022YFA1403800)the Beijing Natural Science Foundation(Grant Nos.2202059 and Z200005)+2 种基金the National Natural Science Foundation of China(Grant Nos.22171283 and 12274459)the Hebei Natural Science Foundation(Grant No.B2020205040)the Beijing National Laboratory for Condensed Matter Physics。
文摘Pressure induced insulator to metal transition followed by the appearance of superconductivity has been observed recently in inorganic quantum spin liquid candidate NaYbSe_(2).In this paper,we study the properties of isostructural compound NaYbS_(2)under pressure.It is found that the resistance of Na YbS_(2)single crystal exhibits an insulating state below 82.9 GPa,but with a drop of more than six orders of magnitude at room temperature.Then a minimum of resistance is observed at about 100.1 GPa and it moves to lower temperature with further compression.Finally,a metallic state in the whole temperature range is observed at about 130.3 GPa accompanied by a non-Fermi liquid behavior below 100 K.The insulator to metal transition,non-monotonic resistance feature and non-Fermi liquid behavior of NaYbS_(2)under pressure are similar to those of NaYbSe_(2),suggesting that these phenomena might be the universal properties in NaLnCh_(2)(Ln=rare earth,Ch=O,S,Se)system.
文摘This paper describes an experimental and theoretical study on an extraction phenomenon of liquids occurring at an air gap between the liquid surface and the electrode by applying a direct current (DC) or low-frequency alternating current (AC) voltage. Three liquids with a different physical property;2,3-dihydrodecafluoropenten, palm fatty acid ester oil and crude rapeseed oil are used as working liquids. The electrode configuration is the sphere or plane (high voltage electrode) to grounded plane electrode. The grounded plane electrode is fixed to the bottom of the test vessel with working liquid and the high voltage electrode is installed in an air above the liquid surface against the grounded plane electrode. The liquid surface swells towards the high voltage electrode by the increase of voltage and the liquid is extracted in a short time, thereafter the air gap between the liquid surface and the high voltage electrode is bridged at a thick liquid column. Such the liquid behavior displays unique features with voltage polarity effect for each working liquid. The relationship between the applied voltage, current variation, height of swollen liquid, force pulling liquid and dynamic feature of liquid is examined experimentally. The liquid behavior is considered theoretically based on experimental observations.
文摘Insulating liquid plays an important role for the life span of the transformer.Petroleum-based mineral oil has become dominant insulating liquid of transformer for more than a century for its excellent dielectric and cooling properties.However,the usage of petroleum-based mineral oil,derived from a nonrenewable energy source,has affected the environment for its nonbiodegradability property.Therefore,researchers direct their attention to renewable and biodegradable alternatives.Palm fatty acid ester,coconut oil,sunflower oil,etc.are considered as alternatives to replace mineral oil as transformer insulation liquid.This paper gives an extensive review of different liquid insulating materials used in a transformer.Characterization of different liquids as an insulating material has been discussed.An attempt has been made to classify different insulating liquids-based on different properties.
