The surface of hollow glass microspheres (HGMs) was roughened by a HCl+NH_(4)F strategy,which achieved a broken ratio as 16.10%,and then metallized by electroless plating by Co nanoparticles up to 90 wt% (abbreviated ...The surface of hollow glass microspheres (HGMs) was roughened by a HCl+NH_(4)F strategy,which achieved a broken ratio as 16.10%,and then metallized by electroless plating by Co nanoparticles up to 90 wt% (abbreviated as Co-HGMs).The average grain size of Co was measured to range from 0.4 to 0.5 μm.Then Co-HGMs were mixed with liquid silicone rubber and xylene,and cured on a perspex plate applicable for flexible electromagnetic shielding.By attentive parameter optimization,a film about 0.836 mm in thickness was obtained with a density of 0.729 g/cm^(3),showing a shielding effectiveness of 15.2 dB in the X-band (8.2-12.4 GHz) at room temperature,which was ascribed to the formation of a conductive network of Co-HGMs inside the film.Simultaneously,the tensile strength of 0.89 MPa at an elongation ratio of 194.5% was also obtained,showing good mechanical properties and tensile strength.展开更多
Deep oil and gas reservoirs are under high-temperature conditions,but traditional coring methods do not consider temperature-preserved measures and ignore the influence of temperature on rock porosity and permeability...Deep oil and gas reservoirs are under high-temperature conditions,but traditional coring methods do not consider temperature-preserved measures and ignore the influence of temperature on rock porosity and permeability,resulting in distorted resource assessments.The development of in situ temperaturepreserved coring(ITP-Coring)technology for deep reservoir rock is urgent,and thermal insulation materials are key.Therefore,hollow glass microsphere/epoxy resin thermal insulation materials(HGM/EP materials)were proposed as thermal insulation materials.The materials properties under coupled hightemperature and high-pressure(HTHP)conditions were tested.The results indicated that high pressures led to HGM destruction and that the materials water absorption significantly increased;additionally,increasing temperature accelerated the process.High temperatures directly caused the thermal conductivity of the materials to increase;additionally,the thermal conduction and convection of water caused by high pressures led to an exponential increase in the thermal conductivity.High temperatures weakened the matrix,and high pressures destroyed the HGM,which resulted in a decrease in the tensile mechanical properties of the materials.The materials entered the high elastic state at 150℃,and the mechanical properties were weakened more obviously,while the pressure led to a significant effect when the water absorption was above 10%.Meanwhile,the tensile strength/strain were 13.62 MPa/1.3%and 6.09 MPa/0.86%at 100℃ and 100 MPa,respectively,which meet the application requirements of the self-designed coring device.Finally,K46-f40 and K46-f50 HGM/EP materials were proven to be suitable for ITP-Coring under coupled conditions below 100℃ and 100 MPa.To further improve the materials properties,the interface layer and EP matrix should be optimized.The results can provide references for the optimization and engineering application of materials and thus technical support for deep oil and gas resource development.展开更多
Liquid hydrogen(LH2)attracts widespread attention because of its highest energy storage density.However,evaporation loss is a serious problem in LH2 storage due to the low boiling point(20 K).Efficient insulation tech...Liquid hydrogen(LH2)attracts widespread attention because of its highest energy storage density.However,evaporation loss is a serious problem in LH2 storage due to the low boiling point(20 K).Efficient insulation technology is an important issue in the study of LH2 storage.Hollow glass microspheres(HGMs)is a potential promising thermal insulation material because of its low apparent thermal conductivity,fast installation(Compared with multi-layer insulation,it can be injected in a short time.),and easy maintenance.A novel cryogenic insulation system consisting of HGMs and a selfevaporating vapor-cooled shield(VCS)is proposed for storage of LH2.A thermodynamic model has been established to analyze the coupled heat transfer characteristics of HGMs and VCS in the composite insulation system.The results show that the combination of HGMs and VCS can effectively reduce heat flux into the LH2 tank.With the increase of VCS number from 1 to 3,the minimum heat flux through HGMs decreases by 57.36%,65.29%,and 68.21%,respectively.Another significant advantage of HGMs is that their thermal insulation properties are not sensitive to ambient vacuum change.When ambient vacuum rises from 10^-3 Pa to 1 Pa,the heat flux into the LH2 tank increases by approximately 20%.When the vacuum rises from 10^-3 Pa to 100 Pa,the combination of VCS and HGMs reduces the heat flux into the tank by 58.08%-69.84% compared with pure HGMs.展开更多
文摘The surface of hollow glass microspheres (HGMs) was roughened by a HCl+NH_(4)F strategy,which achieved a broken ratio as 16.10%,and then metallized by electroless plating by Co nanoparticles up to 90 wt% (abbreviated as Co-HGMs).The average grain size of Co was measured to range from 0.4 to 0.5 μm.Then Co-HGMs were mixed with liquid silicone rubber and xylene,and cured on a perspex plate applicable for flexible electromagnetic shielding.By attentive parameter optimization,a film about 0.836 mm in thickness was obtained with a density of 0.729 g/cm^(3),showing a shielding effectiveness of 15.2 dB in the X-band (8.2-12.4 GHz) at room temperature,which was ascribed to the formation of a conductive network of Co-HGMs inside the film.Simultaneously,the tensile strength of 0.89 MPa at an elongation ratio of 194.5% was also obtained,showing good mechanical properties and tensile strength.
基金supported by the Sichuan Science and Technology Program (Grant Nos.2023NSFSC0004,2023NSFSC0790)the National Natural Science Foundation of China (Grant Nos.51827901,52304033)the Sichuan University Postdoctoral Fund (Grant No.2024SCU12093)。
文摘Deep oil and gas reservoirs are under high-temperature conditions,but traditional coring methods do not consider temperature-preserved measures and ignore the influence of temperature on rock porosity and permeability,resulting in distorted resource assessments.The development of in situ temperaturepreserved coring(ITP-Coring)technology for deep reservoir rock is urgent,and thermal insulation materials are key.Therefore,hollow glass microsphere/epoxy resin thermal insulation materials(HGM/EP materials)were proposed as thermal insulation materials.The materials properties under coupled hightemperature and high-pressure(HTHP)conditions were tested.The results indicated that high pressures led to HGM destruction and that the materials water absorption significantly increased;additionally,increasing temperature accelerated the process.High temperatures directly caused the thermal conductivity of the materials to increase;additionally,the thermal conduction and convection of water caused by high pressures led to an exponential increase in the thermal conductivity.High temperatures weakened the matrix,and high pressures destroyed the HGM,which resulted in a decrease in the tensile mechanical properties of the materials.The materials entered the high elastic state at 150℃,and the mechanical properties were weakened more obviously,while the pressure led to a significant effect when the water absorption was above 10%.Meanwhile,the tensile strength/strain were 13.62 MPa/1.3%and 6.09 MPa/0.86%at 100℃ and 100 MPa,respectively,which meet the application requirements of the self-designed coring device.Finally,K46-f40 and K46-f50 HGM/EP materials were proven to be suitable for ITP-Coring under coupled conditions below 100℃ and 100 MPa.To further improve the materials properties,the interface layer and EP matrix should be optimized.The results can provide references for the optimization and engineering application of materials and thus technical support for deep oil and gas resource development.
基金This research was supported by the State Key Laboratory of Technologies in Space Cryogenic Propellants,China(Grant No.SKLTSCP1903)the National Natural Science Foundation of China(Grant Nos.51706233,51427806,and U1831203)+1 种基金the Strategic Pilot Projects in Space Science of China(Grant No.XDA15010400)the Key Research Program of Frontier Sciences of Chinese Academy of Sciences(Grant No.QYZDY-SSW-JSC028).
文摘Liquid hydrogen(LH2)attracts widespread attention because of its highest energy storage density.However,evaporation loss is a serious problem in LH2 storage due to the low boiling point(20 K).Efficient insulation technology is an important issue in the study of LH2 storage.Hollow glass microspheres(HGMs)is a potential promising thermal insulation material because of its low apparent thermal conductivity,fast installation(Compared with multi-layer insulation,it can be injected in a short time.),and easy maintenance.A novel cryogenic insulation system consisting of HGMs and a selfevaporating vapor-cooled shield(VCS)is proposed for storage of LH2.A thermodynamic model has been established to analyze the coupled heat transfer characteristics of HGMs and VCS in the composite insulation system.The results show that the combination of HGMs and VCS can effectively reduce heat flux into the LH2 tank.With the increase of VCS number from 1 to 3,the minimum heat flux through HGMs decreases by 57.36%,65.29%,and 68.21%,respectively.Another significant advantage of HGMs is that their thermal insulation properties are not sensitive to ambient vacuum change.When ambient vacuum rises from 10^-3 Pa to 1 Pa,the heat flux into the LH2 tank increases by approximately 20%.When the vacuum rises from 10^-3 Pa to 100 Pa,the combination of VCS and HGMs reduces the heat flux into the tank by 58.08%-69.84% compared with pure HGMs.
