CO_(2)flooding enhanced oil recovery(CO_(2)-EOR)represents a significant technology in the low permeability reservoir.With the fractures and heterogeneity in low permeability reservoirs,CO_(2)-EOR is susceptible to pe...CO_(2)flooding enhanced oil recovery(CO_(2)-EOR)represents a significant technology in the low permeability reservoir.With the fractures and heterogeneity in low permeability reservoirs,CO_(2)-EOR is susceptible to pessimistic gas channeling.Consequently,there is a need to develop conformance control materials that can be used in CO_(2)-EOR.Herein,to address the challenges of low strength and poor stability of polymer gel in high temperature and low permeability reservoirs,a new organic/metal ion composite crosslinking polymer gel(AR-Gel)is reported,which is formed by low hydrolysis and medium to high molecular weight polymer(CX-305),organic crosslinking agent(phenolic resin),and aluminium citrate(AI(Ⅲ)).The crosslinking of AI(Ⅲ)with carboxyl group and organic/metal ion double crosslinking can construct a more complex and stable polymer gel structure on the basis of traditional chemical crosslinking,to cope with the harsh conditions such as high temperature.The structure-activity relationship of AR-Gel was revealed by rheology behavior and micro-morphology.The applicability of AR-Gel in reservoir was investigated,as was its strength and stability in supercritical CO_(2).The anti-gas channeling and enhanced oil recovery of AR-Gel were investigated using low permeability fractured cores,and the field process parameters were provided.The gel can be used to meet supercritical CO_(2)reservoirs at 110℃and 20,000 mg/L salinity,with long-term stability over 60 days.The plugging rate of AR-Gel for fractured co re was 97%,with subsequent CO_(2)flooding re sulting in an enhanced oil recovery by 34.5%.ARGel can effectively control CO_(2)gas channeling and enhanced oil recovery.It offers a new material with high strength and temperature resistance,which is particularly beneficial in the CO_(2)flooding for the conformance control of oil field.展开更多
Electrocatalytic reduction of carbon dioxide(CO_(2))to carbon monoxide(CO)is an effective strategy to achieve carbon neutrality.High selective and low-cost catalysts for the electrocatalytic reduction of CO_(2)have re...Electrocatalytic reduction of carbon dioxide(CO_(2))to carbon monoxide(CO)is an effective strategy to achieve carbon neutrality.High selective and low-cost catalysts for the electrocatalytic reduction of CO_(2)have received increasing attention.In contrast to the conventional tube furnace method,the high-temperature shock(HTS)method enables ultra-fast thermal processing,superior atomic efficiency,and a streamlined synthesis protocol,offering a simplified method for the preparation of high-performance single-atom catalysts(SACs).The reports have shown that nickel-based SACs can be synthesized quickly and conveniently using the HTS method,making their application in CO_(2)reduction reactions(CO_(2)RR)a viable and promising avenue for further exploration.In this study,the effect of heating temperature,metal loading and different nitrogen(N)sources on the catalyst morphology,coordination environment and electrocatalytic performance were investigated.Under optimal conditions,0.05Ni-DCD-C-1050 showed excellent performance in reducing CO_(2)to CO,with CO selectivity close to 100%(−0.7 to−1.0 V vs RHE)and current density as high as 130 mA/cm^(2)(−1.1 V vs RHE)in a flow cell under alkaline environment.展开更多
To improve the thermal insulation performance of SiO_(2)aerogels at high temperatures,SiO_(2)precursor solutions were prepared via a sol-gel two-step method.Fe_(2)O_(3)powder was extra added as an opacifier to the SiO...To improve the thermal insulation performance of SiO_(2)aerogels at high temperatures,SiO_(2)precursor solutions were prepared via a sol-gel two-step method.Fe_(2)O_(3)powder was extra added as an opacifier to the SiO_(2)precursor solutions with mass fractions of 0,0.2%,0.5%,1.0%,and 3.0%;and Fe_(2)O_(3)-SiO_(2)composite aerogels were fabricated using CO_(2)supercritical drying technology.The effects of the Fe_(2)O_(3)extra addition on the aerogels were investigated.The results show that:(1)Fe_(2)O_(3)doping does not alter the aerogel morphology;Fe_(2)O_(3)suppresses the mass loss at high temperatures and enhances the high-temperature stability of the composite;(2)below 800℃,the aerogel with 0.5%Fe_(2)O_(3)exhibits the lowest thermal conductivity and the best thermal insulation performance;at 800-1000℃,the aerogel with 1%Fe_(2)O_(3)exhibits the lowest thermal conductivity and a good nanoporous structure;(3)by adjusting the Fe_(2)O_(3)extra addition,composite aerogels suitable for different temperature ranges can be tailored.展开更多
The outermost coating with single phase Ni2Al3 was obtained on copper surface by electrodepositing nickel followed by slurry pack aluminizing at 800 °C for 12 h. The oxidation resistance and microstructure of the...The outermost coating with single phase Ni2Al3 was obtained on copper surface by electrodepositing nickel followed by slurry pack aluminizing at 800 °C for 12 h. The oxidation resistance and microstructure of the coating oxidized in ambient air at 1000 °C for 25-250 h were investigated using SEM, X-ray diffraction and optical microscope methods. The results show that the copper with single phase Ni2Al3 coating possesses the best high temperature oxidation resistance, and the mass gain of the coating is 1/15 that of pure copper and 1/2 that of nickel coating, respectively. The specimen surface after being oxidized for 25 h still comprises Ni2Al3 phase. However, when the time of oxidizing treatment increases to 50 h, the Ni Al phase is formed. It is also found that the Ni2Al3 phase completely turns into Ni Al phase after oxidizing treatment for 100 h and above. The Ni Al coating shows excellent high temperature oxidation resistance when oxidation time is 250 h.展开更多
Two-dimensional tellurium(2D-Te)exhibits strong spin-orbit coupling and a chiral structure.Studying its magnetotransport properties is crucial for the development of spintronic technologies and the exploration of nove...Two-dimensional tellurium(2D-Te)exhibits strong spin-orbit coupling and a chiral structure.Studying its magnetotransport properties is crucial for the development of spintronic technologies and the exploration of novel device applications.The magnetotransport properties of 2D-Te under varying temperatures and high pressures warrant further study.In this paper,the magnetotransport behavior of 2D-Te under low-temperature and high-pressure conditions is investigated.At room temperature,the magnetoresistance(MR)increases with increasing magnetic field,exhibiting positive MR behavior below 4.3 GPa.During decompression,MR is almost constant with decreasing pressure.MR is more sensitive to pressure at lower temperatures.展开更多
Numerical thermodynamic models are proposed for the quaternary fluid system H_(2)O-CO_(2)-NaCl-CaCl_(2)and its ternary subsystems H_(2)O-NaCl-CaCl_(2),H_(2)O-CO_(2)-NaCl,and H_(2)O-CO_(2)-CaCl_(2).The models are valid...Numerical thermodynamic models are proposed for the quaternary fluid system H_(2)O-CO_(2)-NaCl-CaCl_(2)and its ternary subsystems H_(2)O-NaCl-CaCl_(2),H_(2)O-CO_(2)-NaCl,and H_(2)O-CO_(2)-CaCl_(2).The models are valid for temperatures from 150℃to 350℃,pressures from 0.2 to 1.4 kbar,and for arbitrary concentrations of salts.The latter feature is inherited from the earlier developed models of binary systems H_(2)O-NaCl and H_(2)O-CaCl_(2).All the models are formulated in terms of the Gibbs free energy.The entropy term in the equation for the Gibbs free energy of mixing is introduced in a general form,based on the number of different ways of arranging particles in the system that lead to the same total energy.The parameters of the energy terms corresponding to the interactions of particles in binary and ternary subsystems are obtained by fitting published experimental data.The concentrations of salts in the gas phase are simulated based on the salt evaporation free energy.Our model,also available as a computer code,makes it possible to predict the physicochemical properties of fluids involved in hydrothermal processes in the upper crust:the phase state of the system(homogeneous or two-phase fluid),activities of the components,densities,and compositions of the(coexisting)fluid phases.The model offers a numerical tool for analyzing fluid inclusion data and better understanding of metamorphic and metasomatic processes in the upper crust.Fluids at studied P-T conditions play a decisive role in the formation of hydrothermal ore deposits,including most of the world's gold deposits.展开更多
Aiming at the high temperature corrosion in a coal-fired boiler,the effect of H2S and SO2 on the corrosion of 12 CrlMoV under the water wall condition has been investigated by experiments.The results indicate that H2 ...Aiming at the high temperature corrosion in a coal-fired boiler,the effect of H2S and SO2 on the corrosion of 12 CrlMoV under the water wall condition has been investigated by experiments.The results indicate that H2 S can promote the corrosion significantly,and the coarse porous oxide film formed cannot stop the progress of corrosion.While SO2 presents little effect on the corrosion.The main composition of the surface of 12 CrlMoV corrosion products is Fe2 O3.With H2S in the atmosphere,the corrosion gradually develops into deeper layers by forming FeS,FeO and Fe2 O3 alternately.The corrosion rate is doubled for every 50℃ inerease in temperature at 400-500℃.展开更多
Vanadium flow batteries(VFB)offer an ideal solution to the issue of storing massive amounts of electricity produced from intermittent renewables.However,the historical challenge of high thermal precipitation of V_(2)O...Vanadium flow batteries(VFB)offer an ideal solution to the issue of storing massive amounts of electricity produced from intermittent renewables.However,the historical challenge of high thermal precipitation of V_(2)O_(5)from VO_(2)^(+)(~50℃for 1 day)represents a critical concern.Temperature control can alleviate the problem to a certain extent,however,at the expense of the cost of system design and operation.Herein,we report stable electrolyte chemistry at high temperature.By introducing Cr^(3+)as a stabilizer,it bridges with VO_(2)^(+)to form a Cr—O—V^(Ⅴ)structure,which reduces the electron cloud density of V.Therefore,it combines more tightly with H_(2)O and prevents its dehydration process.In addition,the dimerization process of VO_(2)^(+)is also inhibited due to the occupancy of Cr^(3+).As a result,a formed 1.5 M VO_(2)^(+)electrolyte demonstrates a high stability for over 30 days at 50℃(v.s.blank for<1 day at 50℃).Additionally,the low-temperature precipitation temperature of V^(2+)on the negative side has been reduced from 0℃of commercial electrolytes to-5℃.As a proof of concept,a VFB assembled with Nafion 115 membrane demonstrates an energy efficiency(EE)of 80%at 120 mA cm^(-2)for 1000 cycles(50℃).Most importantly,a 4 kW stack can continuously run for~1000 cycles with EE of 80%at 120 mA cm^(-2)without any heat management.Combined with high thermal stability and excellent performance,our design will certainly provide new impetus for the further commercialization of VFB batteries.展开更多
In this work,we coated a layer of Y_(2)O_(3) particles in Hastelloy X(HX)nickel-based superalloy powder by in situ chemical method and combined with laser powder bed fusion(LPBF)technology to develop a high-performanc...In this work,we coated a layer of Y_(2)O_(3) particles in Hastelloy X(HX)nickel-based superalloy powder by in situ chemical method and combined with laser powder bed fusion(LPBF)technology to develop a high-performance Y_(2)O_(3)-doping alloy,designated as Y-HX.The results show that the doping of Y_(2)O_(3) particles prevents crack formation during the printing process and reduces solute segregation at cell and grain boundaries by increasing the viscosity of the molten pool.The doping of Y_(2)O_(3) particles to the printed Y-HX alloy enhances grain boundary characteristics,transforming coarse sheet-like carbides into finely dispersed granular carbides at the boundaries during subsequent heat treatment.Additionally,doping with Y_(2)O_(3) particles increases the recrystallization activation energy of the Y-HX alloy from 149.4 to 278.8 kJ mol^(-1).At 750℃,the Y-HX alloy exhibits an ultimate tensile strength of 619±2 MPa and an elongation of 52%±2%,along with an ultimate tensile strength of 325±3 MPa and an elongation of 47%±2% at 900℃.Our work provides a promising way to develop additive-manufactured superalloys with exceptional thermal stability and remarkable high-temperature mechanical properties.展开更多
Sm-Co permanent magnets are widely used in aerospace equipments,tubes,sensors and hybrid electric vehicles due to their excellent magnetic properties at both room and high temperatures.Compared to that of Nd-Fe-B magn...Sm-Co permanent magnets are widely used in aerospace equipments,tubes,sensors and hybrid electric vehicles due to their excellent magnetic properties at both room and high temperatures.Compared to that of Nd-Fe-B magnets,the capability of reliably operating at temperatures up to 500℃ is the biggest preponderance of Sm-Co permanent magnets.However,the reliable high-temperature magnetic properties are susceptible to composition and technique processes.So,appropriate composition and matched technique processes are prerequisites for good high-temperature magnetic properties.This review mainly emphasizes the influences of Sm,Fe,Cu and Zr contents and technique processes on development of high-temperature performance and discusses the controversial hightemperature coercivity mechanism of 2:17-type high-temperature Sm-Co magnets.展开更多
Wear behaviors of MoSi2 doped with La2O3 against SiC under different loads at 1000 oC in air were investigated by using an XP-5 type high temperature friction and wear tester. The worn surfaces and phases of the sampl...Wear behaviors of MoSi2 doped with La2O3 against SiC under different loads at 1000 oC in air were investigated by using an XP-5 type high temperature friction and wear tester. The worn surfaces and phases of the samples were analyzed by scanning electron microscopy （SEM） and X-ray diffraction, respectively. Results showed that the addition of La2O3 could obviously improve wear resistance of MoSi2. Because of the formation of MoO3 phase on the worn surface, La2O3/MoSi2 composite mainly exhibited oxidation and abrasive wear, which was different from the wear form of MoSi2 such as adhesion, oxidation and abrasion.展开更多
The effect Of Y2O3 as additive to the positive electrode on the high-temperature performances of the Ni-MH batteries was studied. The specific capacities of the positive electrode in Ni-MH battery at higher temperatur...The effect Of Y2O3 as additive to the positive electrode on the high-temperature performances of the Ni-MH batteries was studied. The specific capacities of the positive electrode in Ni-MH battery at higher temperatures are much lower than usual. In order to improve high-temperature performances, charge/discharge curves of the Ni(OH)(2) electrodes with different amounts Of Y2O3 it different temperatures were studied. It is found that the specific capacities of the spherical Ni (OH)(2) with Y2O3 as additive are much higher than those of the regular at higher temperatures. The specific capacity of Ni (OH)(2) containing 1% Y2O3 at 0.2C C/D rate is 35% higher than that of the regular. The specific capacity of Ni (OH)(2) containing 0.2% Y2O3 at 1C C/D rate is 15% higher than that of the regular. Mechanism Of Y2O3 improving high temperature performances of Ni(OH)(2) electrode was also discussed in detail.展开更多
Mechanical properties and microstructural stability under the service temperature are important to the high temperature titanium alloy.In order to evaluate the potential in increase the service temperature of Ti alloy...Mechanical properties and microstructural stability under the service temperature are important to the high temperature titanium alloy.In order to evaluate the potential in increase the service temperature of Ti alloy,two near-αTi alloys with high content of Al asα-stabilizer and Ta,Nb and/or Re asβ-stabilizers were designed and prepared by ingot metallurgy and thermomechanical processing,and the microstructure and mechanical properties before and after thermal exposure at 650℃ for 100 h were characterized.The results indicated that due to the weakβ-stabilizing ability of Ta and Nb elements,only a small amount ofβphase was formed in Ti-10Al-4Ta-2Nb alloy.With a trace Re addition,theβphase was obviously increased in Ti-10Al-4Ta-2Nb-0.25Re,indicating that the Re was a strongβ-stabilizer.Under the same thermomechanical conditions,the Re addition decreased the volume fraction of primaryα(α_(p))phase and refined the secondaryα(α_(s))phase evidently.The primaryαphase presented an obvious core-shell structure in the Ti-10Al-4Ta-2Nb alloy,with higher Al concentration in the shell.While the core-shell structure was not obvious in the Re-containing alloy due to the Re decreases the diffusion of Al,Ta and Nb elements.A large number of orderedα_(2)precipitates can be observed in theα_(p)andα_(s) phases of two alloys.Theα_(2)precipitates continuously grew up during thermal exposure,however,their growth rate in theα_(s)phase of Re-containing alloy were lower than that of Ti-10Al-4Ta-2Nb alloy.Although plenty of orderedα_(2)precipitates formed in the Ti-10Al-4Ta-2Nb alloy,the alloy had a certain plasticity at room temperature.The trace Re addition evidently increased the tensile strength but caused the decrease of the plasticity.After thermal exposure,the strength was further increased,while the plasticity was decreased for both of alloys.展开更多
MoSi2 is presently regarded as the most important material for electrical heating and as one with huge potential for high temperature structural uses. MoSi2 and MoSi2 matrix composites were prepared by self-propagatin...MoSi2 is presently regarded as the most important material for electrical heating and as one with huge potential for high temperature structural uses. MoSi2 and MoSi2 matrix composites were prepared by self-propagating high temperature synthesis （SHS）. Pure MoSi2 was obtained and a compound of MoSi2 and WSi2was synthesized in the form of predominant solid solution （Mo,W）Si2. By adding aluminum of 5.5 at.% to Mo-Si, the crystal structure of MoSi2 changed into a mixture of tetragonal Cllb MoSi2and hexagonal C40 Mo（Si,Al）2. The （Mo,W）Si2-Mo（Si,Al）2-W（Si,Al）2 composite materials were synthesized by adding aluminum of 5.5 at.% to Mo-W-Si. However, if the amount of the added aluminum was not larger than 2.5 at.%, it did not have any significant effect. SHS is an effective technology for synthesis of MoSi2 and MoSi2 matrix composites.展开更多
As a potential candidate for high-energy lithium-ion batteries (LIBs),nickel-rich cathodes encounter significant challenges due to structural instability arising from interphases.In this work,tris(ethenyl)-tris(etheny...As a potential candidate for high-energy lithium-ion batteries (LIBs),nickel-rich cathodes encounter significant challenges due to structural instability arising from interphases.In this work,tris(ethenyl)-tris(ethenyl)silyloxysilane (HVDS) with Si–O bonds and unsaturated bonds is introduced as additive designing functional electrolyte to enhance the long-cycle stability of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)/graphite LIBs at elevated temperature.The preferential oxidization and component of HVDS facilitate the generation of an extremely robust and ultra-thin cathode electrolyte interphase (CEI) comprising a chemically bonded silane polymer.This interphase effectively suppresses side-reactions of electrolyte,mitigates HF erosion,and reduces irreversible phase transitions.Benefiting from the above merits,the batteries’capacity retention shows a remarkable increase from 20% to 92% after nearly 1550 cycles conducted at room temperature.And under elevated temperature conditions (45℃),the capacity retention remains 80%after 670 cycles,in comparison to a drop to 80%after only 250 cycles with the blank electrolyte.These findings highlight HVDS’s potential to functionalize the electrolyte,marking a breakthrough in improving the longevity and reliability of NCM811/graphite LIBs under challenging conditions.展开更多
The true stress-sWain relationships of Ti-5A1-2Sn-2Zr-4Mo-4Cr（TC17） alloy with a wide range of strain rates were investigated by tmiaxial quasi-static and dynamic compression tests, respectively. Quasi- static compr...The true stress-sWain relationships of Ti-5A1-2Sn-2Zr-4Mo-4Cr（TC17） alloy with a wide range of strain rates were investigated by tmiaxial quasi-static and dynamic compression tests, respectively. Quasi- static compression tests were carried out with Instron 8874 test machine, while dynamic compression tests were performed with the split Hopkinson pressure bar （SHPB） which was installed with heating device and synchro- assembly system. The dynamic mechanical behaviors tests of TC17 were carded out from room temperature to 800 ℃ at intervals of 200 ℃ and at high sWain rates （5 500-1 9200 s-l）. The stress-strain curves considering temperature-sWain rate coupling actions were obtained. The Johnson-Cook constitutive model was developed through data fitting of the stress-sWain curves. The material constants in the developed constitutive model can be determined using isothermal and adiabatic stress-strain curves at different strain rates. The Johnson-Cook constitutive model provided satisfied prediction of the plastic flow stress for TC17 alloy.展开更多
Ca2+ and calmodulin antagonist [trifluoperazine(TFP),N-(6-aminohexyl-chloro-1-naphthalenesulfonamide (W7)] pretreatments were conducted on two eggplant varieties Nongyouqie andErmingqie, which have different heat resi...Ca2+ and calmodulin antagonist [trifluoperazine(TFP),N-(6-aminohexyl-chloro-1-naphthalenesulfonamide (W7)] pretreatments were conducted on two eggplant varieties Nongyouqie andErmingqie, which have different heat resistance. The results showed that under 40C(day/night), Ca2+ immersion pretreatment enabled the eggplant seedlings to keep relatively higheractivities of superoxide dismutase(SOD) and peroxidase(POD), reduced the production rate ofsuperoxide anion O2_ and the content of malondialdehyde(MDA), alleviated the damage of reducedglutathione(GSH) and the accumulation of proline (Pro), whereas calmodulin antagonist TFP andW7 immersion pretreatments could lead to more rapid loss of SOD and POD activities, increasethe contents of MDA, Pro and production rate of O2_, aggravate the damage of GSH. Under the samestress condition, heat-resistant variety Nongyouqie was less injured compared to the heat-sensitive variety Erminqie. These data indicated that Ca2+-CaM signal transduction systemmight regulate the heat resistance of eggplant seedlings by controlling the activity of someantioxidant enzymes and the contents of antioxidant substance.展开更多
During high speed machining in the field of manufacture,chip formation is a severe plastic deformation process including large strain,high strain rate and high temperature.And the strain rate in high speed cutting pro...During high speed machining in the field of manufacture,chip formation is a severe plastic deformation process including large strain,high strain rate and high temperature.And the strain rate in high speed cutting process can be achieved to 105 s^（-1）.30CrMnSiNi2Asteel is a kind of important high-strength low-alloy structural steel with wide application range.Obtaining the dynamic mechanical properties of30CrMnSiNi2Aunder the conditions of high strain rate and high temperature is necessary to construct the constitutive relation model for high speed machining.The dynamic compressive mechanical properties of30CrMnSiNi2Asteel were studied using split Hopkinson pressure bar（SHPB）tests at 30-700°C and3000-10000s^（-1）.The stress-strain curves of 30CrMnSiNi2Asteel at different temperatures and strain rates were investigated,and the strain hardening effect and temperature effect were discussed.Experimental results show that 30CrMnSiNi2Ahas obvious temperature sensitivity at 300°C.Moreover,the flow stress decreased significantly with the increase of temperature.The strain hardening effect of the material at high strain rate is not significant with the increase of strain.The strain rate hardening effect is obvious with increasing the temperature.According to the experimental results,the established Johnson-Cook（J-C）constitutive model of 30CrMnSiNi2Asteel could be used at high strain rate and high temperature.展开更多
High-temperature thermoelectric transport property measurements have been performed on the highly c-axis oriented Bi2Sr2Co20v thin films prepared by pulsed laser deposition on LaA1Oa （001）. Both the electric resisti...High-temperature thermoelectric transport property measurements have been performed on the highly c-axis oriented Bi2Sr2Co20v thin films prepared by pulsed laser deposition on LaA1Oa （001）. Both the electric resistivity p and the seebeck coefficient S of the film exhibit an increasing trend with the temperature from 300 K-1000 K and reach up to 4.8 m. cm and 202 V/K at 980 K, resulting in a power factor of 0.85 mW/mK which are comparable to those of the single crystalline samples. A small polaron hopping conduction can be responsible for the conduction mechanism of the film at high temperature. The results demonstrate that the Bi2Sr2Co2Oy thin film has potential application has high temperature thin film thermoelectric devices,展开更多
The stability of Ti2AlN at high pressure of 5 GPa and different temperatures of 700-1 600 ℃ was investigated using X-ray diffraction （XRD）,scanning electron microscopy （SEM） equipped with an energy dispersive spe...The stability of Ti2AlN at high pressure of 5 GPa and different temperatures of 700-1 600 ℃ was investigated using X-ray diffraction （XRD）,scanning electron microscopy （SEM） equipped with an energy dispersive spectrometer （EDS）.Ti2AlN was found to be stable at temperatures as high as 1 400 ℃under 5 GPa for 20 min,and was proved that it held better structure stability than Ti2AlC under 5 GPa through comparative experiments of Ti2AlN and Ti2AlC （representative compounds of M2AX phases （211 phase））.The reaction process at high pressure had some difference from that at ambient pressure/vacuum,and Ti2AlN directly decomposed to TiN and TiAl at 5 GPa and 1 500 ℃ for 20 min.Moreover,the mechanism of phase segregation was discussed.In addition,the behavior of Ti2AlN contacting with Zr at high pressure and high temperature （HPHT） was also studied.展开更多
基金project was supported by the Fund of State Key Laboratory of Deep Oil and Gas,China University of Petroleum(East China)(No.SKLDOG2024-ZYRC-06)Key Program of National Natural Science Foundation of China(52130401)+1 种基金National Natural Science Foundation of China(52104055,52374058)Shandong Provincial Natural Science Foundation,China(ZR2021ME171,ZR2024YQ043)。
文摘CO_(2)flooding enhanced oil recovery(CO_(2)-EOR)represents a significant technology in the low permeability reservoir.With the fractures and heterogeneity in low permeability reservoirs,CO_(2)-EOR is susceptible to pessimistic gas channeling.Consequently,there is a need to develop conformance control materials that can be used in CO_(2)-EOR.Herein,to address the challenges of low strength and poor stability of polymer gel in high temperature and low permeability reservoirs,a new organic/metal ion composite crosslinking polymer gel(AR-Gel)is reported,which is formed by low hydrolysis and medium to high molecular weight polymer(CX-305),organic crosslinking agent(phenolic resin),and aluminium citrate(AI(Ⅲ)).The crosslinking of AI(Ⅲ)with carboxyl group and organic/metal ion double crosslinking can construct a more complex and stable polymer gel structure on the basis of traditional chemical crosslinking,to cope with the harsh conditions such as high temperature.The structure-activity relationship of AR-Gel was revealed by rheology behavior and micro-morphology.The applicability of AR-Gel in reservoir was investigated,as was its strength and stability in supercritical CO_(2).The anti-gas channeling and enhanced oil recovery of AR-Gel were investigated using low permeability fractured cores,and the field process parameters were provided.The gel can be used to meet supercritical CO_(2)reservoirs at 110℃and 20,000 mg/L salinity,with long-term stability over 60 days.The plugging rate of AR-Gel for fractured co re was 97%,with subsequent CO_(2)flooding re sulting in an enhanced oil recovery by 34.5%.ARGel can effectively control CO_(2)gas channeling and enhanced oil recovery.It offers a new material with high strength and temperature resistance,which is particularly beneficial in the CO_(2)flooding for the conformance control of oil field.
基金supported by the National Key R&D Program of China(2024YFB4106400)National Natural Science Foundation of China(22209200,52302331)。
文摘Electrocatalytic reduction of carbon dioxide(CO_(2))to carbon monoxide(CO)is an effective strategy to achieve carbon neutrality.High selective and low-cost catalysts for the electrocatalytic reduction of CO_(2)have received increasing attention.In contrast to the conventional tube furnace method,the high-temperature shock(HTS)method enables ultra-fast thermal processing,superior atomic efficiency,and a streamlined synthesis protocol,offering a simplified method for the preparation of high-performance single-atom catalysts(SACs).The reports have shown that nickel-based SACs can be synthesized quickly and conveniently using the HTS method,making their application in CO_(2)reduction reactions(CO_(2)RR)a viable and promising avenue for further exploration.In this study,the effect of heating temperature,metal loading and different nitrogen(N)sources on the catalyst morphology,coordination environment and electrocatalytic performance were investigated.Under optimal conditions,0.05Ni-DCD-C-1050 showed excellent performance in reducing CO_(2)to CO,with CO selectivity close to 100%(−0.7 to−1.0 V vs RHE)and current density as high as 130 mA/cm^(2)(−1.1 V vs RHE)in a flow cell under alkaline environment.
文摘To improve the thermal insulation performance of SiO_(2)aerogels at high temperatures,SiO_(2)precursor solutions were prepared via a sol-gel two-step method.Fe_(2)O_(3)powder was extra added as an opacifier to the SiO_(2)precursor solutions with mass fractions of 0,0.2%,0.5%,1.0%,and 3.0%;and Fe_(2)O_(3)-SiO_(2)composite aerogels were fabricated using CO_(2)supercritical drying technology.The effects of the Fe_(2)O_(3)extra addition on the aerogels were investigated.The results show that:(1)Fe_(2)O_(3)doping does not alter the aerogel morphology;Fe_(2)O_(3)suppresses the mass loss at high temperatures and enhances the high-temperature stability of the composite;(2)below 800℃,the aerogel with 0.5%Fe_(2)O_(3)exhibits the lowest thermal conductivity and the best thermal insulation performance;at 800-1000℃,the aerogel with 1%Fe_(2)O_(3)exhibits the lowest thermal conductivity and a good nanoporous structure;(3)by adjusting the Fe_(2)O_(3)extra addition,composite aerogels suitable for different temperature ranges can be tailored.
基金Projects(CKJB201205,QKJB201202,YJK201307)supported by the Nanjing Institute of Technology,China
文摘The outermost coating with single phase Ni2Al3 was obtained on copper surface by electrodepositing nickel followed by slurry pack aluminizing at 800 °C for 12 h. The oxidation resistance and microstructure of the coating oxidized in ambient air at 1000 °C for 25-250 h were investigated using SEM, X-ray diffraction and optical microscope methods. The results show that the copper with single phase Ni2Al3 coating possesses the best high temperature oxidation resistance, and the mass gain of the coating is 1/15 that of pure copper and 1/2 that of nickel coating, respectively. The specimen surface after being oxidized for 25 h still comprises Ni2Al3 phase. However, when the time of oxidizing treatment increases to 50 h, the Ni Al phase is formed. It is also found that the Ni2Al3 phase completely turns into Ni Al phase after oxidizing treatment for 100 h and above. The Ni Al coating shows excellent high temperature oxidation resistance when oxidation time is 250 h.
基金supported by the National Key R&D Program of China(Grant No.2023YFA1406200)the National Natural Science Foundation of China(Grant No.12304067)+1 种基金the Natural Science Foundation of Shandong Province(Grant Nos.ZR2021QA087 and ZR2021QA092)the Special Construction Project Fund for Shandong Province Taishan Scholars。
文摘Two-dimensional tellurium(2D-Te)exhibits strong spin-orbit coupling and a chiral structure.Studying its magnetotransport properties is crucial for the development of spintronic technologies and the exploration of novel device applications.The magnetotransport properties of 2D-Te under varying temperatures and high pressures warrant further study.In this paper,the magnetotransport behavior of 2D-Te under low-temperature and high-pressure conditions is investigated.At room temperature,the magnetoresistance(MR)increases with increasing magnetic field,exhibiting positive MR behavior below 4.3 GPa.During decompression,MR is almost constant with decreasing pressure.MR is more sensitive to pressure at lower temperatures.
基金the Research Program of the IPGG RAS FMUW-2021-0002.
文摘Numerical thermodynamic models are proposed for the quaternary fluid system H_(2)O-CO_(2)-NaCl-CaCl_(2)and its ternary subsystems H_(2)O-NaCl-CaCl_(2),H_(2)O-CO_(2)-NaCl,and H_(2)O-CO_(2)-CaCl_(2).The models are valid for temperatures from 150℃to 350℃,pressures from 0.2 to 1.4 kbar,and for arbitrary concentrations of salts.The latter feature is inherited from the earlier developed models of binary systems H_(2)O-NaCl and H_(2)O-CaCl_(2).All the models are formulated in terms of the Gibbs free energy.The entropy term in the equation for the Gibbs free energy of mixing is introduced in a general form,based on the number of different ways of arranging particles in the system that lead to the same total energy.The parameters of the energy terms corresponding to the interactions of particles in binary and ternary subsystems are obtained by fitting published experimental data.The concentrations of salts in the gas phase are simulated based on the salt evaporation free energy.Our model,also available as a computer code,makes it possible to predict the physicochemical properties of fluids involved in hydrothermal processes in the upper crust:the phase state of the system(homogeneous or two-phase fluid),activities of the components,densities,and compositions of the(coexisting)fluid phases.The model offers a numerical tool for analyzing fluid inclusion data and better understanding of metamorphic and metasomatic processes in the upper crust.Fluids at studied P-T conditions play a decisive role in the formation of hydrothermal ore deposits,including most of the world's gold deposits.
基金supported by the National Key Research and Development Plan of China (No. 2018YFB0604203)
文摘Aiming at the high temperature corrosion in a coal-fired boiler,the effect of H2S and SO2 on the corrosion of 12 CrlMoV under the water wall condition has been investigated by experiments.The results indicate that H2 S can promote the corrosion significantly,and the coarse porous oxide film formed cannot stop the progress of corrosion.While SO2 presents little effect on the corrosion.The main composition of the surface of 12 CrlMoV corrosion products is Fe2 O3.With H2S in the atmosphere,the corrosion gradually develops into deeper layers by forming FeS,FeO and Fe2 O3 alternately.The corrosion rate is doubled for every 50℃ inerease in temperature at 400-500℃.
基金financially supported by National Key R&D Program of China(2022YFB2404903)Strategic Priority Research Program of the Chinese Academy of Sciences(XDA0400201)+6 种基金International Partnership Program of Chinese Academy of Sciences(121421KYSB20210028)National Natural Science Foundation of China(22209179,22478379)Liaoning Provincial Natural Science Foundation(2023-MS-010)Science and Technology Major Project of Liaoning Province(2024JH1/11700011)International Science and Technology Cooperation program of Liaoning(2023JH2/10700002)Liaoning Bidding for Key Technology Project(2022JH1/10800038,2023JH1/10400065)Liaoning Binhai Laboratory Funding(LBLA-2022-02,LBLB-2023-01)。
文摘Vanadium flow batteries(VFB)offer an ideal solution to the issue of storing massive amounts of electricity produced from intermittent renewables.However,the historical challenge of high thermal precipitation of V_(2)O_(5)from VO_(2)^(+)(~50℃for 1 day)represents a critical concern.Temperature control can alleviate the problem to a certain extent,however,at the expense of the cost of system design and operation.Herein,we report stable electrolyte chemistry at high temperature.By introducing Cr^(3+)as a stabilizer,it bridges with VO_(2)^(+)to form a Cr—O—V^(Ⅴ)structure,which reduces the electron cloud density of V.Therefore,it combines more tightly with H_(2)O and prevents its dehydration process.In addition,the dimerization process of VO_(2)^(+)is also inhibited due to the occupancy of Cr^(3+).As a result,a formed 1.5 M VO_(2)^(+)electrolyte demonstrates a high stability for over 30 days at 50℃(v.s.blank for<1 day at 50℃).Additionally,the low-temperature precipitation temperature of V^(2+)on the negative side has been reduced from 0℃of commercial electrolytes to-5℃.As a proof of concept,a VFB assembled with Nafion 115 membrane demonstrates an energy efficiency(EE)of 80%at 120 mA cm^(-2)for 1000 cycles(50℃).Most importantly,a 4 kW stack can continuously run for~1000 cycles with EE of 80%at 120 mA cm^(-2)without any heat management.Combined with high thermal stability and excellent performance,our design will certainly provide new impetus for the further commercialization of VFB batteries.
基金the National Key R&D Program of China(No.2023YFB3712002)the National Natural Science Founda-tion of China(Grant Nos.U22A20172 and 52171044)the Seed Foundation of Tianjin University(Grant No.2023XZL-0015).
文摘In this work,we coated a layer of Y_(2)O_(3) particles in Hastelloy X(HX)nickel-based superalloy powder by in situ chemical method and combined with laser powder bed fusion(LPBF)technology to develop a high-performance Y_(2)O_(3)-doping alloy,designated as Y-HX.The results show that the doping of Y_(2)O_(3) particles prevents crack formation during the printing process and reduces solute segregation at cell and grain boundaries by increasing the viscosity of the molten pool.The doping of Y_(2)O_(3) particles to the printed Y-HX alloy enhances grain boundary characteristics,transforming coarse sheet-like carbides into finely dispersed granular carbides at the boundaries during subsequent heat treatment.Additionally,doping with Y_(2)O_(3) particles increases the recrystallization activation energy of the Y-HX alloy from 149.4 to 278.8 kJ mol^(-1).At 750℃,the Y-HX alloy exhibits an ultimate tensile strength of 619±2 MPa and an elongation of 52%±2%,along with an ultimate tensile strength of 325±3 MPa and an elongation of 47%±2% at 900℃.Our work provides a promising way to develop additive-manufactured superalloys with exceptional thermal stability and remarkable high-temperature mechanical properties.
基金financially supported by the National Natural Science Foundation of China(Nos.51871063,51571064 and 51590882)。
文摘Sm-Co permanent magnets are widely used in aerospace equipments,tubes,sensors and hybrid electric vehicles due to their excellent magnetic properties at both room and high temperatures.Compared to that of Nd-Fe-B magnets,the capability of reliably operating at temperatures up to 500℃ is the biggest preponderance of Sm-Co permanent magnets.However,the reliable high-temperature magnetic properties are susceptible to composition and technique processes.So,appropriate composition and matched technique processes are prerequisites for good high-temperature magnetic properties.This review mainly emphasizes the influences of Sm,Fe,Cu and Zr contents and technique processes on development of high-temperature performance and discusses the controversial hightemperature coercivity mechanism of 2:17-type high-temperature Sm-Co magnets.
基金supported by the National Natural Science Foundation of China (51071133)
文摘Wear behaviors of MoSi2 doped with La2O3 against SiC under different loads at 1000 oC in air were investigated by using an XP-5 type high temperature friction and wear tester. The worn surfaces and phases of the samples were analyzed by scanning electron microscopy （SEM） and X-ray diffraction, respectively. Results showed that the addition of La2O3 could obviously improve wear resistance of MoSi2. Because of the formation of MoO3 phase on the worn surface, La2O3/MoSi2 composite mainly exhibited oxidation and abrasive wear, which was different from the wear form of MoSi2 such as adhesion, oxidation and abrasion.
文摘The effect Of Y2O3 as additive to the positive electrode on the high-temperature performances of the Ni-MH batteries was studied. The specific capacities of the positive electrode in Ni-MH battery at higher temperatures are much lower than usual. In order to improve high-temperature performances, charge/discharge curves of the Ni(OH)(2) electrodes with different amounts Of Y2O3 it different temperatures were studied. It is found that the specific capacities of the spherical Ni (OH)(2) with Y2O3 as additive are much higher than those of the regular at higher temperatures. The specific capacity of Ni (OH)(2) containing 1% Y2O3 at 0.2C C/D rate is 35% higher than that of the regular. The specific capacity of Ni (OH)(2) containing 0.2% Y2O3 at 1C C/D rate is 15% higher than that of the regular. Mechanism Of Y2O3 improving high temperature performances of Ni(OH)(2) electrode was also discussed in detail.
基金financially support by National Key Research and Development Program of China(No.2017YFB0306205)National Natural Science Foundation of China(NSFC,No.51671012)+1 种基金the Fundamental Research Funds for the Central UniversitiesInternational Science and Technology Cooperation Program of China(2015DFA51430)。
文摘Mechanical properties and microstructural stability under the service temperature are important to the high temperature titanium alloy.In order to evaluate the potential in increase the service temperature of Ti alloy,two near-αTi alloys with high content of Al asα-stabilizer and Ta,Nb and/or Re asβ-stabilizers were designed and prepared by ingot metallurgy and thermomechanical processing,and the microstructure and mechanical properties before and after thermal exposure at 650℃ for 100 h were characterized.The results indicated that due to the weakβ-stabilizing ability of Ta and Nb elements,only a small amount ofβphase was formed in Ti-10Al-4Ta-2Nb alloy.With a trace Re addition,theβphase was obviously increased in Ti-10Al-4Ta-2Nb-0.25Re,indicating that the Re was a strongβ-stabilizer.Under the same thermomechanical conditions,the Re addition decreased the volume fraction of primaryα(α_(p))phase and refined the secondaryα(α_(s))phase evidently.The primaryαphase presented an obvious core-shell structure in the Ti-10Al-4Ta-2Nb alloy,with higher Al concentration in the shell.While the core-shell structure was not obvious in the Re-containing alloy due to the Re decreases the diffusion of Al,Ta and Nb elements.A large number of orderedα_(2)precipitates can be observed in theα_(p)andα_(s) phases of two alloys.Theα_(2)precipitates continuously grew up during thermal exposure,however,their growth rate in theα_(s)phase of Re-containing alloy were lower than that of Ti-10Al-4Ta-2Nb alloy.Although plenty of orderedα_(2)precipitates formed in the Ti-10Al-4Ta-2Nb alloy,the alloy had a certain plasticity at room temperature.The trace Re addition evidently increased the tensile strength but caused the decrease of the plasticity.After thermal exposure,the strength was further increased,while the plasticity was decreased for both of alloys.
基金This project was financially supported by the National Natural Science Foundation of China (No. 50025412)
文摘MoSi2 is presently regarded as the most important material for electrical heating and as one with huge potential for high temperature structural uses. MoSi2 and MoSi2 matrix composites were prepared by self-propagating high temperature synthesis （SHS）. Pure MoSi2 was obtained and a compound of MoSi2 and WSi2was synthesized in the form of predominant solid solution （Mo,W）Si2. By adding aluminum of 5.5 at.% to Mo-Si, the crystal structure of MoSi2 changed into a mixture of tetragonal Cllb MoSi2and hexagonal C40 Mo（Si,Al）2. The （Mo,W）Si2-Mo（Si,Al）2-W（Si,Al）2 composite materials were synthesized by adding aluminum of 5.5 at.% to Mo-W-Si. However, if the amount of the added aluminum was not larger than 2.5 at.%, it did not have any significant effect. SHS is an effective technology for synthesis of MoSi2 and MoSi2 matrix composites.
基金financially supported by the Scientific Research Innovation Project of Graduate School of South China Normal University (No. 2024KYLX081)。
文摘As a potential candidate for high-energy lithium-ion batteries (LIBs),nickel-rich cathodes encounter significant challenges due to structural instability arising from interphases.In this work,tris(ethenyl)-tris(ethenyl)silyloxysilane (HVDS) with Si–O bonds and unsaturated bonds is introduced as additive designing functional electrolyte to enhance the long-cycle stability of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)/graphite LIBs at elevated temperature.The preferential oxidization and component of HVDS facilitate the generation of an extremely robust and ultra-thin cathode electrolyte interphase (CEI) comprising a chemically bonded silane polymer.This interphase effectively suppresses side-reactions of electrolyte,mitigates HF erosion,and reduces irreversible phase transitions.Benefiting from the above merits,the batteries’capacity retention shows a remarkable increase from 20% to 92% after nearly 1550 cycles conducted at room temperature.And under elevated temperature conditions (45℃),the capacity retention remains 80%after 670 cycles,in comparison to a drop to 80%after only 250 cycles with the blank electrolyte.These findings highlight HVDS’s potential to functionalize the electrolyte,marking a breakthrough in improving the longevity and reliability of NCM811/graphite LIBs under challenging conditions.
基金Funded by the National Basic Research Program of China(No.2009CB724401)the Major Science and Technology Program of High-end CNC Machine Tools and Basic Manufacturing Equipment(No.2012ZX04003-041)
文摘The true stress-sWain relationships of Ti-5A1-2Sn-2Zr-4Mo-4Cr（TC17） alloy with a wide range of strain rates were investigated by tmiaxial quasi-static and dynamic compression tests, respectively. Quasi- static compression tests were carried out with Instron 8874 test machine, while dynamic compression tests were performed with the split Hopkinson pressure bar （SHPB） which was installed with heating device and synchro- assembly system. The dynamic mechanical behaviors tests of TC17 were carded out from room temperature to 800 ℃ at intervals of 200 ℃ and at high sWain rates （5 500-1 9200 s-l）. The stress-strain curves considering temperature-sWain rate coupling actions were obtained. The Johnson-Cook constitutive model was developed through data fitting of the stress-sWain curves. The material constants in the developed constitutive model can be determined using isothermal and adiabatic stress-strain curves at different strain rates. The Johnson-Cook constitutive model provided satisfied prediction of the plastic flow stress for TC17 alloy.
文摘Ca2+ and calmodulin antagonist [trifluoperazine(TFP),N-(6-aminohexyl-chloro-1-naphthalenesulfonamide (W7)] pretreatments were conducted on two eggplant varieties Nongyouqie andErmingqie, which have different heat resistance. The results showed that under 40C(day/night), Ca2+ immersion pretreatment enabled the eggplant seedlings to keep relatively higheractivities of superoxide dismutase(SOD) and peroxidase(POD), reduced the production rate ofsuperoxide anion O2_ and the content of malondialdehyde(MDA), alleviated the damage of reducedglutathione(GSH) and the accumulation of proline (Pro), whereas calmodulin antagonist TFP andW7 immersion pretreatments could lead to more rapid loss of SOD and POD activities, increasethe contents of MDA, Pro and production rate of O2_, aggravate the damage of GSH. Under the samestress condition, heat-resistant variety Nongyouqie was less injured compared to the heat-sensitive variety Erminqie. These data indicated that Ca2+-CaM signal transduction systemmight regulate the heat resistance of eggplant seedlings by controlling the activity of someantioxidant enzymes and the contents of antioxidant substance.
基金supported by the National High Technology Research and Development Program of China(2014AA041504)the National Natural Science Foundation of China(51605161)
文摘During high speed machining in the field of manufacture,chip formation is a severe plastic deformation process including large strain,high strain rate and high temperature.And the strain rate in high speed cutting process can be achieved to 105 s^（-1）.30CrMnSiNi2Asteel is a kind of important high-strength low-alloy structural steel with wide application range.Obtaining the dynamic mechanical properties of30CrMnSiNi2Aunder the conditions of high strain rate and high temperature is necessary to construct the constitutive relation model for high speed machining.The dynamic compressive mechanical properties of30CrMnSiNi2Asteel were studied using split Hopkinson pressure bar（SHPB）tests at 30-700°C and3000-10000s^（-1）.The stress-strain curves of 30CrMnSiNi2Asteel at different temperatures and strain rates were investigated,and the strain hardening effect and temperature effect were discussed.Experimental results show that 30CrMnSiNi2Ahas obvious temperature sensitivity at 300°C.Moreover,the flow stress decreased significantly with the increase of temperature.The strain hardening effect of the material at high strain rate is not significant with the increase of strain.The strain rate hardening effect is obvious with increasing the temperature.According to the experimental results,the established Johnson-Cook（J-C）constitutive model of 30CrMnSiNi2Asteel could be used at high strain rate and high temperature.
基金Project supported by the Young Scientists Fund of the National Natural Science Foundation of China (Grant No. 10904030)the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20091301120002)
文摘High-temperature thermoelectric transport property measurements have been performed on the highly c-axis oriented Bi2Sr2Co20v thin films prepared by pulsed laser deposition on LaA1Oa （001）. Both the electric resistivity p and the seebeck coefficient S of the film exhibit an increasing trend with the temperature from 300 K-1000 K and reach up to 4.8 m. cm and 202 V/K at 980 K, resulting in a power factor of 0.85 mW/mK which are comparable to those of the single crystalline samples. A small polaron hopping conduction can be responsible for the conduction mechanism of the film at high temperature. The results demonstrate that the Bi2Sr2Co2Oy thin film has potential application has high temperature thin film thermoelectric devices,
基金Funded by the National Natural Science Foundation of China (Nos.50572067,10772126)
文摘The stability of Ti2AlN at high pressure of 5 GPa and different temperatures of 700-1 600 ℃ was investigated using X-ray diffraction （XRD）,scanning electron microscopy （SEM） equipped with an energy dispersive spectrometer （EDS）.Ti2AlN was found to be stable at temperatures as high as 1 400 ℃under 5 GPa for 20 min,and was proved that it held better structure stability than Ti2AlC under 5 GPa through comparative experiments of Ti2AlN and Ti2AlC （representative compounds of M2AX phases （211 phase））.The reaction process at high pressure had some difference from that at ambient pressure/vacuum,and Ti2AlN directly decomposed to TiN and TiAl at 5 GPa and 1 500 ℃ for 20 min.Moreover,the mechanism of phase segregation was discussed.In addition,the behavior of Ti2AlN contacting with Zr at high pressure and high temperature （HPHT） was also studied.
