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
High-temperature thin-film strain sensors are advanced technological devices for monitoring stress and strain in extreme environments,but the coupling of temperature and strain at high temperature is a challenge for t...High-temperature thin-film strain sensors are advanced technological devices for monitoring stress and strain in extreme environments,but the coupling of temperature and strain at high temperature is a challenge for their use.Here,this issue is addressed by creating a composite ink that combines Pb_(2)Ru_(2)O_(6) and TiB_(2) using polysilazane(PSZ)as a binder.After direct writing and annealing the PSZ/Pb_(2)Ru_(2)O_(6)/TiB_(2) film at 800℃ in air,the resulting thin film exhibits a low temperature coefficient of resistance(TCR)of only 281 ppm/℃ over a wide temperature range from 100℃ to 700℃,while also demonstrating high sensitivity with a gauge factor approaching 19.8.This exceptional performance is attributed to the intrinsic properties of Pb_(2)Ru_(2)O_(6),which has positive TCR at high temperature,and TiB2,which has negative TCR at high temperature.Combining these materials reduces the overall TCR of the film.Tests showed that the PSZ/Pb_(2)Ru_(2)O_(6)/TiB_(2) film maintains stable strain responses and significant signal output even under varying temperature.These findings provide valuable insights for developing high-temperature strain sensors with low TCR and high sensitivity,highlighting their potential for applications in high-temperature strain measurements.展开更多
The z-axis-inclined 3D printing process using short carbon fiber-reinforced thermoplastic composites offers the potential for the support-free fabrication of complex structures and theoretically unlimited extension of...The z-axis-inclined 3D printing process using short carbon fiber-reinforced thermoplastic composites offers the potential for the support-free fabrication of complex structures and theoretically unlimited extension of printed components.It has emerged as a promising approach for in-orbit manufacturing of high-performance thermoplastic composite truss structures.However,extreme conditions of the space environment,such as high vacuum and fluctuating high-low temperatures,significantly alter the heat-transfer behavior during the printing process,often resulting in dimensional inaccuracies and degraded mechanical performance.Existing process optimization strategies fail to account for the coupled effects of vacuum and thermal extremes,limiting their applicability in guiding process design under varying vacuum temperature conditions.To address this gap,this study establishes a truss3D printing experimental platform with in situ temperature-monitoring capability under ground-simulated space conditions.It systematically investigates the effects of printing speed and structural geometry on the pre-bonding surface temperature and forming quality of truss structures in high-low temperature vacuum environments.This study reveals the mechanism by which processing and structural parameters affect the component performance through their influence on the pre-bonding surface temperature and dimensional accuracy.The experimental results show that under high-temperature vacuum conditions,the pre-bonding surface temperature is relatively high,resulting in good interfacial bonding.However,increasing the printing speed reduces the forming accuracy and leads to a decline in mechanical performance.In contrast,under low-temperature vacuum conditions,where the pre-bonding surface temperatures are lower,increasing the printing speed within a specific range effectively increases the surface temperature and bonding quality,thereby improving mechanical properties.Additionally,owing to frequent path transitions,the diagonal-strut truss exhibits a lower forming accuracy and pre-bonding surface temperature than the infilling truss,resulting in inferior mechanical performance in high-low temperature vacuum environments.展开更多
[Objective] The research aimed to provide the certain theory basis for the accurate forecast and early warning of high and low temperature in the east of Hexi Corridor.[Method] Based on the high(the daily highest temp...[Objective] The research aimed to provide the certain theory basis for the accurate forecast and early warning of high and low temperature in the east of Hexi Corridor.[Method] Based on the high(the daily highest temperature ≥35 ℃) and low(the daily lowest temperature ≤-20 ℃) temperature data in five observatories in the east of Hexi Corridor during 1960-2009,the temporal and spatial distribution,intensity,continuity and circulation situation of high and low temperature were analyzed in detail by using the statistical method.[Result] The high temperature weather in the east of Hexi Corridor mainly happened in the edge of northeast desert,and the low temperature mainly happened in the mountain zone where the altitude was higher and the edge of north desert.As the climate became warm,the high temperature days showed the weak increase trend,and the intensity strengthened.The low temperature days showed the obvious decrease trend,and the intensity weakened.The high temperature weather mainly occurred in June,August,and the low temperature mainly occurred in January,February,December.The high and low temperature weather had the durative characteristic.The strong high and low temperature mainly occurred in the durative time of high and low temperature.The high temperature weather appeared in the zone where was controlled and affected by the subtropical high.The low temperature weather appeared in the zone where the strong cold air accumulated and invaded.[Conclusion] The research had the extremely important significance on servicing for the agriculture,preventing and reducing the natural disasters,promoting the local economic development.展开更多
Tomato(Solanum lycopersicum)is an extensively cultivated vegetable,and its growth and fruit quality can be significantly impaired by low temperatures.The widespread presence of N^(6)-methyladenosine(m^(6)A)modificatio...Tomato(Solanum lycopersicum)is an extensively cultivated vegetable,and its growth and fruit quality can be significantly impaired by low temperatures.The widespread presence of N^(6)-methyladenosine(m^(6)A)modification on RNA is involved in a diverse range of stress response processes.There is a significant knowledge gap regarding the precise roles of m^(6)A modification in tomato,particularly for cold stress response.Here,we assessed the m^(6)A modification landscape of S.lycopersicum'Micro-Tom'leaves in response to low-temperature stress.Furthermore,we investigated the potential relationship among m^(6)A modification,transcriptional regulation,alternative polyadenylation events,and protein translation via MeRIP-seq,RNA-seq,and protein mass spectrometry.After omic date analysis,11378 and 10735 significant m^(6)A peak associated genes were identified in the control and cold treatment tomato leaves,respectively.Additionally,we observed a UGUACAK(K=G/U)motif under both conditions.Differential m^(6)A site associated genes most likely play roles in protein translation regulatory pathway.Besides directly altering gene expression levels,m^(6)A also leads to differential poly(A)site usage under low-temperature.Finally,24 important candidate genes associated with cold stress were identified by system-level multi-omic analysis.Among them,m^(6)A modification levels were increased in SBPase(Sedoheptulose-1,7-bisphosphatase,Solyc05g052600.4)mRNA,causing distal poly(A)site usage,downregulation of mRNA expression level,and increased protein abundance.Through these,tomato leaves try to maintain normal photo synthetic carbon assimilation and nitro gen metabolism under low-temperature condition.The comprehensive investigation of the m^(6)A modification landscape and multi-omics analysis provide valuable insights into the epigenetic regulatory mechanisms in tomato cold stress response.展开更多
Microstructure observations and drop-weight tear test were performed to study the microstructures and mechanical properties of two kinds of industrial X70 and two kinds of industrial X80 grade pipeline steels. The eff...Microstructure observations and drop-weight tear test were performed to study the microstructures and mechanical properties of two kinds of industrial X70 and two kinds of industrial X80 grade pipeline steels. The effective grain size and the fraction of high angle grain boundaries in the pipeline steels were investigated by electron backscatter diffraction analysis. It is found that the low temperature toughness of the pipeline steels depends not only on the effective grain size, but also on other microstructural factors such as martensite-austenite （MA） constituents and precipitates. The morphology and size of MA constituents significantly affect the mechanical properties of the pipeline steels. Nubby MA constituents with large size have significant negative effects on the toughness, while smaller granular MA constituents have less harmful effects. Similarly, larger Ti-rich nitrides with sharp corners have a strongly negative effect on the toughness, while fine, spherical Nb-rich carbides have a less deleterious effect. The low temperature toughness of the steels is independent of the fraction of high angle grain boundaries.展开更多
A suitable carburized microstructure with fine granular dispersed carbides in hypereutectoid zone,ultra fine martensite in matrix and recrystallized austenite to be refined to the grain size of 12～14 has been obtaine...A suitable carburized microstructure with fine granular dispersed carbides in hypereutectoid zone,ultra fine martensite in matrix and recrystallized austenite to be refined to the grain size of 12～14 has been obtained by a new process,which is a high carbon concentration carburizing with rare earth element at low temperature(860～880℃)in a discontinuous gas carburization furnace.There was not much difference for the microstructure in eutectic zone between this and conventional process.Forming mechanism of granular carbides has been also studied in this paper.展开更多
Cr is the most important element in nickel-based alloys to prevent high temperature oxidation and corrosion. However, high-Cr content will lead to a decline of hot workability which limits the addition of Cr for most ...Cr is the most important element in nickel-based alloys to prevent high temperature oxidation and corrosion. However, high-Cr content will lead to a decline of hot workability which limits the addition of Cr for most nickel-based superalloys. In order to add more Cr into Ni-based alloy for improving high temperature oxidation and corrosion resistance, the poor hot workability of high-Cr alloy must be first solved. Deformation characteristic of a high-Cr nickel-based alloy （40 wt% Cr） under hot compression conditions at 800-1200 ℃ has been investigated by using a Gleeble 3500 machine, and the microstructural evolution during hot working process has been observed by optical microscopy and scanning electron microscopy. The results show that a high-temperature low-plasticity （HTLP） region exists in this high-Cr nickel-based alloy. This phenomenon can be attributed to its non-uniform interdendritic microstructure at high temperatures. These results can explain the poor hot workability of high-Cr nickel-based alloy.展开更多
In this work, a parametric approach is presented and utilized to determine the creep properties of weldments; then the model of creep strain for cross weld specimen is given. On the basis of the experimental results, ...In this work, a parametric approach is presented and utilized to determine the creep properties of weldments; then the model of creep strain for cross weld specimen is given. On the basis of the experimental results, attempt has been made to establish equations of the isochronous stress-strain for weld joint that can predict the function of loading and service time in use of the creep data of base metal and weld metal.展开更多
Piezoelectric ceramics of 0.6(Bi0.9La0.1)FeO3-0.4Pb(Ti1-xMnx)O3 (BLF-PTM) for x=0, 0.01, 0.02, and 0.03 were prepared by sol-gel process combined with a solid-state reaction method. The tan? for BLF-PTM of x=0.01 is j...Piezoelectric ceramics of 0.6(Bi0.9La0.1)FeO3-0.4Pb(Ti1-xMnx)O3 (BLF-PTM) for x=0, 0.01, 0.02, and 0.03 were prepared by sol-gel process combined with a solid-state reaction method. The tan? for BLF-PTM of x=0.01 is just 0.006 at 1 kHz, drastically decreasing by using Mn dopants. The TC increases to 490 ℃ for BLF-PTM of x=0.02. Furthermore, Mn modification effectively enhances the poling state and the piezoelectric properties of BLF-PTM. The kp, Qm, d33, and g33 of 0.34, 403, and 124 pC1·N-1 and 37×10-3 Vm·N-1 are achieved for BLF-PTM of x=0.01. The results indicate that Mn modified BLF-PTM is a competitive high power and high temperature piezoelectric material with excellent piezoelectric properties.展开更多
High resistance thin film chip resistors(0603 type) were studied,and the specifications are as follows:1 k? with tolerance about ±0.1% after laser trimming and temperature coefficient of resistance(TCR) less than...High resistance thin film chip resistors(0603 type) were studied,and the specifications are as follows:1 k? with tolerance about ±0.1% after laser trimming and temperature coefficient of resistance(TCR) less than ±15×10-6/℃.Cr-Si-Ta-Al films were prepared with Ar flow rate and sputtering power fixed at 20 standard-state cubic centimeter per minute(sccm) and 100 W,respectively.The experiment shows that the electrical properties of Cr-SiTa-Al deposition films can meet the specification requirements of 0603 ty...展开更多
H_(2)S selective catalytic oxidation technology is a prospective way for the treatment of low concentration acid gas with simple process operation and low investment. However, undesirable results such as large formati...H_(2)S selective catalytic oxidation technology is a prospective way for the treatment of low concentration acid gas with simple process operation and low investment. However, undesirable results such as large formation of SO_(2) and catalyst deactivation inevitably occur, due to the temperature rise of fixed reaction bed caused by the exothermic reaction. Catalyst with high activity in wide operating temperature window, especially in high temperature range, is urgently needed. In this paper, a series of copper-substituted hexaaluminate catalysts (LaCu_(x), x = 0, 0.5, 1, 1.5, 2, 2.5) were prepared and investigated for the H_(2)S selective oxidation reaction at high temperature conditions (300-550℃). The LaCu_(1) catalyst exhibited excellent catalytic performance and great stability, which was attributed to the best reductive properties and proper pore structure. Besides, two facile deep processing paths were proposed to eliminate the remaining H_(2)S and SO_(2) in the tail gas.展开更多
Micro-supercapacitors(MSCs)are considered as highly competitive power sources for miniaturized electronics.However,narrow voltage window and poor anti-freezing properties of MSCs in conventional aqueous electrolytes l...Micro-supercapacitors(MSCs)are considered as highly competitive power sources for miniaturized electronics.However,narrow voltage window and poor anti-freezing properties of MSCs in conventional aqueous electrolytes lead to low energy density and limited environmental adaption.Herein,we report the construction of low-temperature and high-energy-density MSCs based on anti-freezing hybrid gel electrolytes(HGE)through introducing ethylene glycol(EG)additives into aqueous LiCl electrolyte.Since EG partially destroys hydrogen bond network among water molecules,the HGE exhibits maximum electrochemical stability window of 2.7 V and superior anti-freezing features with a glass transition temperature of-62.8℃.Further,the optimized MSCs using activated carbon microelectrodes possess impressive volumetric capacitance of 28.9 F cm^(-3)and energy density of 10.3 mWh cm^(-3)in the voltage of 1.6 V,2.6 times higher than MSCs tested in 1.2 V.Importantly,the MSCs display 68.3%capacitance retention even at-30℃ compared to the value at 25℃,and ultra-long cyclability with 85.7%of initial capacitance after 15,000 times,indicating extraordinary low-temperature performance.Besides,our devices offer favorable flexibility and modular integration.Therefore,this work provides a general strategy of realizing flexible,safe and anti-freezing microscale power sources,holding great potential towards subzero-temperature microelectronic applications.展开更多
High salt and low temperature are the bottlenecks for the remove of oil contaminants by enriched crude-oil degrading microbiota in Liaohe Estuarine Wetland(LEW),China.To improve the performance of crude-oil removal,mi...High salt and low temperature are the bottlenecks for the remove of oil contaminants by enriched crude-oil degrading microbiota in Liaohe Estuarine Wetland(LEW),China.To improve the performance of crude-oil removal,microbiota was further immobilized by two methods,i.e.,sodium alginate(SA),and polyvinyl alcohol and sodium alginate(PVA+SA).Results showed that the crude oil was effectively removed by the enrichment with an average degrading ratio of 19.42-31.45 mg(L d)^(−1).The optimal inoculum size for the n-alkanes removal was 10%and 99.89%.Some members of genera Acinetobacter,Actinophytocola,Aquabac-terium,Dysgonomonas,Frigidibacter,Sphingobium,Serpens,and Pseudomonas dominated in crude-oil degrading microflora.Though the removal efficiency was lower than free bacteria when the temperature was 15℃,SA and PVA+SA immobilization im-proved the resistance to salinity.The composite crude-oil degrading microbiota in this study demonstrated a perspective potential for crude oil removal from surface water under high salinity and low temperature conditions.展开更多
Deformation mechanisms and magnetic properties of medium and high entropy alloys(MEA/HEAs)closely relate to lattice distortion and are strongly temperature-dependent,in particular,at low temperature ranges.However,lit...Deformation mechanisms and magnetic properties of medium and high entropy alloys(MEA/HEAs)closely relate to lattice distortion and are strongly temperature-dependent,in particular,at low temperature ranges.However,little attention has been paid to the evolution of lattice distortion with temperature decreasing and its effects on deformation behavior and magnetic state transition.In this work,we carry out in situ synchrotron radiation based X-ray powder diffraction(SR-XRD)experiments from 293 to 123 K aiming for determining lattice distortion evolutions of Cr Co Ni MEA,Cr Fe Co Ni and Cr Mn Fe Co Ni HEAs.Magnetic measurements at corresponding low temperatures and cryogenic ranges are further conducted.The in situ SR-XRD results demonstrate a general reduction of lattice distortion magnitude with temperature decreasing,which shows a similar tendency with that of reported stacking fault energy(SFE)values.It is thus suggested that lattice distortion reduction possibly makes a critical contribution to deformation mechanism transition.The magnetic measurement results show a clear ferromagnetic transition of Cr Fe Co Ni HEA when temperature is below 173 K.While,no obvious magnetic state transition is observed for Cr Co Ni MEA and Cr Mn Fe Co Ni HEA.The present findings on lattice distortion evolutions will pave the way for designing targeted HEAs with particular properties.展开更多
To investigate the influence of tantalum content on high-temperature mechanical properties of low-carbon reduced acti- vation ferritic/martensitic （RAFM） steels, RAFM steels containing different tantalum contents （...To investigate the influence of tantalum content on high-temperature mechanical properties of low-carbon reduced acti- vation ferritic/martensitic （RAFM） steels, RAFM steels containing different tantalum contents （0 and 0.073%） were fabricated, and the tensile tests at room temperature and high temperature were performed, as well as the creep tests were conducted at 550 ~C with the applied stress of 180 and 220 MPa. It was found that 0.073% tantalum addition results in the increase in amount of stable carbonitrides （MX）, and the creep rupture time of the steel under 180 MPa is obviously increased. In addition, the increase in MX caused by tantalum addition also leads to the improvement of high-temperature tensile strength. The improvement of high-temperature mechanical properties of RAFM steels is primarily related to the evolution of precipitates.展开更多
Low carbon bainitic steel derives the high strength mainly from high density of dislocations rather than carbon and alloy element content, so it tends to evolve into equilibrium microstructure with low density of disl...Low carbon bainitic steel derives the high strength mainly from high density of dislocations rather than carbon and alloy element content, so it tends to evolve into equilibrium microstructure with low density of dislocations under thermal disturbance. In the present investigation, granular bainite and lath-like bainitic ferrite were produced respectively in Mo-free low-carbon steels by changing cooling rate;. It has been found that granular bainite possesses a lower strength at room temperature than bainitic ferrite, but it exhibits a slower decrease of strength with temperature increasing. Dislocation density in both granular bainite and bainitic ferrite decreases via recovery and recrystallization at high temperature. However, when reheating of bainite is carded out at temperature below 600 ℃, a long time will be needed for incubation of recrystallization, during which the hardness of bainite maintains stable. The property makes bainite, especially granular bainite, become a potential microstructure for matrix of high strength fire-resistant steel.展开更多
A series of oxygen-doped RE_2CuO_4 (RE=Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm) was synthesized using high-pressure/oxygen-doped technique. The structures and low temperature magnetic properties were investigated. The XRD ...A series of oxygen-doped RE_2CuO_4 (RE=Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm) was synthesized using high-pressure/oxygen-doped technique. The structures and low temperature magnetic properties were investigated. The XRD patterns indicate that the structures of high oxygen pressure RE_2CuO_4 (only for RE=Sm, Eu) samples are pure T′ phase, but when RE= Gd, Tb, Dy, Ho, Er, Tm, the structures turn to disorder. The magnetic anomalies that occurred at T^30 K are observed in high oxygen pressure RE_2CuO_4. It is found that the transition temperatures of weak ferromagnetic anomalies are nearly independent of the rare-earth components. Thus, the O-doping plays an important role in anomalous magnetic properties of RE_2CuO_(4+δ). The magnetic anomalies in RE_2CuO_4 are considered to be due to ferromagnetic clusters formed in the Cu-O plane after the oxygen doping.展开更多
Based on the time-dependent strain cyclic characteristics and fatigue behaviors of SS304 stainless steel under multi-axial cyclic loading at 700 ？ C, and in the frame of unified visoco-plastic cyclic constitutive mod...Based on the time-dependent strain cyclic characteristics and fatigue behaviors of SS304 stainless steel under multi-axial cyclic loading at 700 ？ C, and in the frame of unified visoco-plastic cyclic constitutive model and continuum damage mechanics theory, the damage-coupled multi-axial time-dependent constitutive model and fatigue failure model were proposed. In the model, the evolution equation of damage was introduced in and the time-dependent effects, e.g. holding time, loading rate, were taken into account. The model was applied to the simulation of whole-life cyclic deformation behaviors and prediction of LCF life for SS304 stainless steel in multiaxial time-dependent low cycle fatigue tests. It is shown that the simulated results agree well with experimental ones.展开更多
We briefly introduce a new high-pressure transport measurement system integrated with low temperature and magnetic field that is being established as one of the user experimental stations of the Synergetic Extreme Con...We briefly introduce a new high-pressure transport measurement system integrated with low temperature and magnetic field that is being established as one of the user experimental stations of the Synergetic Extreme Condition User Facilities in the Huairou District of Beijing, China. To demonstrate the capabilities of the system for condensed matter research, the emergence of some pressure-induced phenomena and physics related to superconductivity found previously is also introduced, and then a perspective for such an advanced high-pressure system is presented.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the National Key Research and Development Program of China(Grant No.2021YFB2012100)the Major Science and Technology Projects in Fujian Province(Grant No.2023HZ021005)+1 种基金the Open Project Program of Fujian Key Laboratory of Special Intelligent Equipment Measurement and Control(Grant No.FJIES2023KF06)the Industry-University-Research Co-operation Fund of the Eighth Research Institute of China Aerospace Science and Technology Corporation(Grant No.SAST2023-061).
文摘High-temperature thin-film strain sensors are advanced technological devices for monitoring stress and strain in extreme environments,but the coupling of temperature and strain at high temperature is a challenge for their use.Here,this issue is addressed by creating a composite ink that combines Pb_(2)Ru_(2)O_(6) and TiB_(2) using polysilazane(PSZ)as a binder.After direct writing and annealing the PSZ/Pb_(2)Ru_(2)O_(6)/TiB_(2) film at 800℃ in air,the resulting thin film exhibits a low temperature coefficient of resistance(TCR)of only 281 ppm/℃ over a wide temperature range from 100℃ to 700℃,while also demonstrating high sensitivity with a gauge factor approaching 19.8.This exceptional performance is attributed to the intrinsic properties of Pb_(2)Ru_(2)O_(6),which has positive TCR at high temperature,and TiB2,which has negative TCR at high temperature.Combining these materials reduces the overall TCR of the film.Tests showed that the PSZ/Pb_(2)Ru_(2)O_(6)/TiB_(2) film maintains stable strain responses and significant signal output even under varying temperature.These findings provide valuable insights for developing high-temperature strain sensors with low TCR and high sensitivity,highlighting their potential for applications in high-temperature strain measurements.
基金supported by National Key Research and Development Program of China(Grant No.2023YFB4605301)the National Natural Science Foundation of China(Grant No.52130506)。
文摘The z-axis-inclined 3D printing process using short carbon fiber-reinforced thermoplastic composites offers the potential for the support-free fabrication of complex structures and theoretically unlimited extension of printed components.It has emerged as a promising approach for in-orbit manufacturing of high-performance thermoplastic composite truss structures.However,extreme conditions of the space environment,such as high vacuum and fluctuating high-low temperatures,significantly alter the heat-transfer behavior during the printing process,often resulting in dimensional inaccuracies and degraded mechanical performance.Existing process optimization strategies fail to account for the coupled effects of vacuum and thermal extremes,limiting their applicability in guiding process design under varying vacuum temperature conditions.To address this gap,this study establishes a truss3D printing experimental platform with in situ temperature-monitoring capability under ground-simulated space conditions.It systematically investigates the effects of printing speed and structural geometry on the pre-bonding surface temperature and forming quality of truss structures in high-low temperature vacuum environments.This study reveals the mechanism by which processing and structural parameters affect the component performance through their influence on the pre-bonding surface temperature and dimensional accuracy.The experimental results show that under high-temperature vacuum conditions,the pre-bonding surface temperature is relatively high,resulting in good interfacial bonding.However,increasing the printing speed reduces the forming accuracy and leads to a decline in mechanical performance.In contrast,under low-temperature vacuum conditions,where the pre-bonding surface temperatures are lower,increasing the printing speed within a specific range effectively increases the surface temperature and bonding quality,thereby improving mechanical properties.Additionally,owing to frequent path transitions,the diagonal-strut truss exhibits a lower forming accuracy and pre-bonding surface temperature than the infilling truss,resulting in inferior mechanical performance in high-low temperature vacuum environments.
基金Supported by Gansu Province the Fifth Installment "Ten Plan"~~
文摘[Objective] The research aimed to provide the certain theory basis for the accurate forecast and early warning of high and low temperature in the east of Hexi Corridor.[Method] Based on the high(the daily highest temperature ≥35 ℃) and low(the daily lowest temperature ≤-20 ℃) temperature data in five observatories in the east of Hexi Corridor during 1960-2009,the temporal and spatial distribution,intensity,continuity and circulation situation of high and low temperature were analyzed in detail by using the statistical method.[Result] The high temperature weather in the east of Hexi Corridor mainly happened in the edge of northeast desert,and the low temperature mainly happened in the mountain zone where the altitude was higher and the edge of north desert.As the climate became warm,the high temperature days showed the weak increase trend,and the intensity strengthened.The low temperature days showed the obvious decrease trend,and the intensity weakened.The high temperature weather mainly occurred in June,August,and the low temperature mainly occurred in January,February,December.The high and low temperature weather had the durative characteristic.The strong high and low temperature mainly occurred in the durative time of high and low temperature.The high temperature weather appeared in the zone where was controlled and affected by the subtropical high.The low temperature weather appeared in the zone where the strong cold air accumulated and invaded.[Conclusion] The research had the extremely important significance on servicing for the agriculture,preventing and reducing the natural disasters,promoting the local economic development.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.32202518 and 32070601)Shandong University of Technology PhD Start-up Fund(418097)。
文摘Tomato(Solanum lycopersicum)is an extensively cultivated vegetable,and its growth and fruit quality can be significantly impaired by low temperatures.The widespread presence of N^(6)-methyladenosine(m^(6)A)modification on RNA is involved in a diverse range of stress response processes.There is a significant knowledge gap regarding the precise roles of m^(6)A modification in tomato,particularly for cold stress response.Here,we assessed the m^(6)A modification landscape of S.lycopersicum'Micro-Tom'leaves in response to low-temperature stress.Furthermore,we investigated the potential relationship among m^(6)A modification,transcriptional regulation,alternative polyadenylation events,and protein translation via MeRIP-seq,RNA-seq,and protein mass spectrometry.After omic date analysis,11378 and 10735 significant m^(6)A peak associated genes were identified in the control and cold treatment tomato leaves,respectively.Additionally,we observed a UGUACAK(K=G/U)motif under both conditions.Differential m^(6)A site associated genes most likely play roles in protein translation regulatory pathway.Besides directly altering gene expression levels,m^(6)A also leads to differential poly(A)site usage under low-temperature.Finally,24 important candidate genes associated with cold stress were identified by system-level multi-omic analysis.Among them,m^(6)A modification levels were increased in SBPase(Sedoheptulose-1,7-bisphosphatase,Solyc05g052600.4)mRNA,causing distal poly(A)site usage,downregulation of mRNA expression level,and increased protein abundance.Through these,tomato leaves try to maintain normal photo synthetic carbon assimilation and nitro gen metabolism under low-temperature condition.The comprehensive investigation of the m^(6)A modification landscape and multi-omics analysis provide valuable insights into the epigenetic regulatory mechanisms in tomato cold stress response.
文摘Microstructure observations and drop-weight tear test were performed to study the microstructures and mechanical properties of two kinds of industrial X70 and two kinds of industrial X80 grade pipeline steels. The effective grain size and the fraction of high angle grain boundaries in the pipeline steels were investigated by electron backscatter diffraction analysis. It is found that the low temperature toughness of the pipeline steels depends not only on the effective grain size, but also on other microstructural factors such as martensite-austenite （MA） constituents and precipitates. The morphology and size of MA constituents significantly affect the mechanical properties of the pipeline steels. Nubby MA constituents with large size have significant negative effects on the toughness, while smaller granular MA constituents have less harmful effects. Similarly, larger Ti-rich nitrides with sharp corners have a strongly negative effect on the toughness, while fine, spherical Nb-rich carbides have a less deleterious effect. The low temperature toughness of the steels is independent of the fraction of high angle grain boundaries.
文摘A suitable carburized microstructure with fine granular dispersed carbides in hypereutectoid zone,ultra fine martensite in matrix and recrystallized austenite to be refined to the grain size of 12～14 has been obtained by a new process,which is a high carbon concentration carburizing with rare earth element at low temperature(860～880℃)in a discontinuous gas carburization furnace.There was not much difference for the microstructure in eutectic zone between this and conventional process.Forming mechanism of granular carbides has been also studied in this paper.
基金support from the National Natural Science Foundation of China, No.50771011
文摘Cr is the most important element in nickel-based alloys to prevent high temperature oxidation and corrosion. However, high-Cr content will lead to a decline of hot workability which limits the addition of Cr for most nickel-based superalloys. In order to add more Cr into Ni-based alloy for improving high temperature oxidation and corrosion resistance, the poor hot workability of high-Cr alloy must be first solved. Deformation characteristic of a high-Cr nickel-based alloy （40 wt% Cr） under hot compression conditions at 800-1200 ℃ has been investigated by using a Gleeble 3500 machine, and the microstructural evolution during hot working process has been observed by optical microscopy and scanning electron microscopy. The results show that a high-temperature low-plasticity （HTLP） region exists in this high-Cr nickel-based alloy. This phenomenon can be attributed to its non-uniform interdendritic microstructure at high temperatures. These results can explain the poor hot workability of high-Cr nickel-based alloy.
基金supports provided by Natural Science Foundation of Shanghai(contract No.03ZR14022)the“Tenth Five”National Key Technological Research and Development Program(contract No.2001BA803B03)National Natural Science Foundation of China(contract No.50225517)are gratefully acknowledged.
文摘In this work, a parametric approach is presented and utilized to determine the creep properties of weldments; then the model of creep strain for cross weld specimen is given. On the basis of the experimental results, attempt has been made to establish equations of the isochronous stress-strain for weld joint that can predict the function of loading and service time in use of the creep data of base metal and weld metal.
基金financially supported by National Nature Science Foundation of China(No.50872080)Shanghai Special Foundation of Nanotechnology(No.1052nm07300)+2 种基金Shanghai Education Development Foundation(No.08SG41)Shanghai Leading Academic Disciplines(No.S30107)Innovational Foundation of Shanghai University
文摘Piezoelectric ceramics of 0.6(Bi0.9La0.1)FeO3-0.4Pb(Ti1-xMnx)O3 (BLF-PTM) for x=0, 0.01, 0.02, and 0.03 were prepared by sol-gel process combined with a solid-state reaction method. The tan? for BLF-PTM of x=0.01 is just 0.006 at 1 kHz, drastically decreasing by using Mn dopants. The TC increases to 490 ℃ for BLF-PTM of x=0.02. Furthermore, Mn modification effectively enhances the poling state and the piezoelectric properties of BLF-PTM. The kp, Qm, d33, and g33 of 0.34, 403, and 124 pC1·N-1 and 37×10-3 Vm·N-1 are achieved for BLF-PTM of x=0.01. The results indicate that Mn modified BLF-PTM is a competitive high power and high temperature piezoelectric material with excellent piezoelectric properties.
基金Supported by Science and Technology Committee of Tianjin (No.06YFGPGX08400)Ministry of Science and Technology of China (No.2009GJF20022)Innovation Fund of Tianjin University
文摘High resistance thin film chip resistors(0603 type) were studied,and the specifications are as follows:1 k? with tolerance about ±0.1% after laser trimming and temperature coefficient of resistance(TCR) less than ±15×10-6/℃.Cr-Si-Ta-Al films were prepared with Ar flow rate and sputtering power fixed at 20 standard-state cubic centimeter per minute(sccm) and 100 W,respectively.The experiment shows that the electrical properties of Cr-SiTa-Al deposition films can meet the specification requirements of 0603 ty...
基金financially supported by the National Natural Science Foundation of China (Nos. 21976176, 22006148)the Key R&D Program of Shandong province (No. 2019JZZY010506)the Fundamental Research Funds for the Central Universities。
文摘H_(2)S selective catalytic oxidation technology is a prospective way for the treatment of low concentration acid gas with simple process operation and low investment. However, undesirable results such as large formation of SO_(2) and catalyst deactivation inevitably occur, due to the temperature rise of fixed reaction bed caused by the exothermic reaction. Catalyst with high activity in wide operating temperature window, especially in high temperature range, is urgently needed. In this paper, a series of copper-substituted hexaaluminate catalysts (LaCu_(x), x = 0, 0.5, 1, 1.5, 2, 2.5) were prepared and investigated for the H_(2)S selective oxidation reaction at high temperature conditions (300-550℃). The LaCu_(1) catalyst exhibited excellent catalytic performance and great stability, which was attributed to the best reductive properties and proper pore structure. Besides, two facile deep processing paths were proposed to eliminate the remaining H_(2)S and SO_(2) in the tail gas.
基金financially supported by the National Natural Science Foundation of China(22125903,51872283,22109160,22005297)the Dalian Innovation Support Plan for High Level Talents(2019RT09)+6 种基金the The Joint Fund of the Yulin University and the Dalian National Laboratory For Clean Energy(DNL),CAS,DNL Cooperation Fund,CAS(DNL201912,DNL201915,DNL202016,DNL202019),DICP(DICP ZZBS201802,DICP I2020032)The Joint Fund of the Yulin University and the Dalian National Laboratory for Clean Energy(YLU-DNL Fund 2021002,YLU-DNL Fund 2021009)the China Postdoctoral Science Foundation(2021M693126,2020M680995,2021M703145,2021M693127)the International Postdoctoral Exchange Fellowship Program(Talent-Introduction Program)(YJ20210311)the Plan for promoting innovative talents of Education Department of Liaoning Province(LCR2018015)the Shenyang Youth Science and Technology Project(RC200444)the Natural Science Foundation of Liaoning Province(2021-MS-234)。
文摘Micro-supercapacitors(MSCs)are considered as highly competitive power sources for miniaturized electronics.However,narrow voltage window and poor anti-freezing properties of MSCs in conventional aqueous electrolytes lead to low energy density and limited environmental adaption.Herein,we report the construction of low-temperature and high-energy-density MSCs based on anti-freezing hybrid gel electrolytes(HGE)through introducing ethylene glycol(EG)additives into aqueous LiCl electrolyte.Since EG partially destroys hydrogen bond network among water molecules,the HGE exhibits maximum electrochemical stability window of 2.7 V and superior anti-freezing features with a glass transition temperature of-62.8℃.Further,the optimized MSCs using activated carbon microelectrodes possess impressive volumetric capacitance of 28.9 F cm^(-3)and energy density of 10.3 mWh cm^(-3)in the voltage of 1.6 V,2.6 times higher than MSCs tested in 1.2 V.Importantly,the MSCs display 68.3%capacitance retention even at-30℃ compared to the value at 25℃,and ultra-long cyclability with 85.7%of initial capacitance after 15,000 times,indicating extraordinary low-temperature performance.Besides,our devices offer favorable flexibility and modular integration.Therefore,this work provides a general strategy of realizing flexible,safe and anti-freezing microscale power sources,holding great potential towards subzero-temperature microelectronic applications.
基金supported by the National Key R&D Program of China(No.2018YFD0900805)the Start up Foundation for Introducing Talent of Nanjing Univer-sity of Information Science and Technology。
文摘High salt and low temperature are the bottlenecks for the remove of oil contaminants by enriched crude-oil degrading microbiota in Liaohe Estuarine Wetland(LEW),China.To improve the performance of crude-oil removal,microbiota was further immobilized by two methods,i.e.,sodium alginate(SA),and polyvinyl alcohol and sodium alginate(PVA+SA).Results showed that the crude oil was effectively removed by the enrichment with an average degrading ratio of 19.42-31.45 mg(L d)^(−1).The optimal inoculum size for the n-alkanes removal was 10%and 99.89%.Some members of genera Acinetobacter,Actinophytocola,Aquabac-terium,Dysgonomonas,Frigidibacter,Sphingobium,Serpens,and Pseudomonas dominated in crude-oil degrading microflora.Though the removal efficiency was lower than free bacteria when the temperature was 15℃,SA and PVA+SA immobilization im-proved the resistance to salinity.The composite crude-oil degrading microbiota in this study demonstrated a perspective potential for crude oil removal from surface water under high salinity and low temperature conditions.
基金financially supported by the National Key Research and Development Program of China(No.2017YFB0702003)the National Science Foundation of China(Nos.12002341,11790292 and 11672316)+4 种基金the NSFC Basic Science Center Program for“Multiscale Problems in Nonlinear Mechanics”(No.11988102)the Strategic Priority Research Program(Nos.XDB22040302 and XDB22040303)the Key Research Program of Frontier Sciences(No.QYZDJSSWJSC011)the Science Challenge Project(No.TZ2016001)the Zhejiang Provincial Natural Science Foundation(No.LGG21E010005)。
文摘Deformation mechanisms and magnetic properties of medium and high entropy alloys(MEA/HEAs)closely relate to lattice distortion and are strongly temperature-dependent,in particular,at low temperature ranges.However,little attention has been paid to the evolution of lattice distortion with temperature decreasing and its effects on deformation behavior and magnetic state transition.In this work,we carry out in situ synchrotron radiation based X-ray powder diffraction(SR-XRD)experiments from 293 to 123 K aiming for determining lattice distortion evolutions of Cr Co Ni MEA,Cr Fe Co Ni and Cr Mn Fe Co Ni HEAs.Magnetic measurements at corresponding low temperatures and cryogenic ranges are further conducted.The in situ SR-XRD results demonstrate a general reduction of lattice distortion magnitude with temperature decreasing,which shows a similar tendency with that of reported stacking fault energy(SFE)values.It is thus suggested that lattice distortion reduction possibly makes a critical contribution to deformation mechanism transition.The magnetic measurement results show a clear ferromagnetic transition of Cr Fe Co Ni HEA when temperature is below 173 K.While,no obvious magnetic state transition is observed for Cr Co Ni MEA and Cr Mn Fe Co Ni HEA.The present findings on lattice distortion evolutions will pave the way for designing targeted HEAs with particular properties.
基金financially supported by the China National Funds for Distinguished Young Scientists(Grant No.51325401)the National Magnetic Confinement Fusion Energy Research Project(Grant No.2015GB119001)the National Natural Science Foundation of China(Grant Nos.51501126,51474156 and U1660201)
文摘To investigate the influence of tantalum content on high-temperature mechanical properties of low-carbon reduced acti- vation ferritic/martensitic （RAFM） steels, RAFM steels containing different tantalum contents （0 and 0.073%） were fabricated, and the tensile tests at room temperature and high temperature were performed, as well as the creep tests were conducted at 550 ~C with the applied stress of 180 and 220 MPa. It was found that 0.073% tantalum addition results in the increase in amount of stable carbonitrides （MX）, and the creep rupture time of the steel under 180 MPa is obviously increased. In addition, the increase in MX caused by tantalum addition also leads to the improvement of high-temperature tensile strength. The improvement of high-temperature mechanical properties of RAFM steels is primarily related to the evolution of precipitates.
文摘Low carbon bainitic steel derives the high strength mainly from high density of dislocations rather than carbon and alloy element content, so it tends to evolve into equilibrium microstructure with low density of dislocations under thermal disturbance. In the present investigation, granular bainite and lath-like bainitic ferrite were produced respectively in Mo-free low-carbon steels by changing cooling rate;. It has been found that granular bainite possesses a lower strength at room temperature than bainitic ferrite, but it exhibits a slower decrease of strength with temperature increasing. Dislocation density in both granular bainite and bainitic ferrite decreases via recovery and recrystallization at high temperature. However, when reheating of bainite is carded out at temperature below 600 ℃, a long time will be needed for incubation of recrystallization, during which the hardness of bainite maintains stable. The property makes bainite, especially granular bainite, become a potential microstructure for matrix of high strength fire-resistant steel.
文摘A series of oxygen-doped RE_2CuO_4 (RE=Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm) was synthesized using high-pressure/oxygen-doped technique. The structures and low temperature magnetic properties were investigated. The XRD patterns indicate that the structures of high oxygen pressure RE_2CuO_4 (only for RE=Sm, Eu) samples are pure T′ phase, but when RE= Gd, Tb, Dy, Ho, Er, Tm, the structures turn to disorder. The magnetic anomalies that occurred at T^30 K are observed in high oxygen pressure RE_2CuO_4. It is found that the transition temperatures of weak ferromagnetic anomalies are nearly independent of the rare-earth components. Thus, the O-doping plays an important role in anomalous magnetic properties of RE_2CuO_(4+δ). The magnetic anomalies in RE_2CuO_4 are considered to be due to ferromagnetic clusters formed in the Cu-O plane after the oxygen doping.
基金supported by the Fundamental Research Funds for the Central Universities (No.SWJTU09ZT35)National Science Fund for Distinguished Young Scholars of China (No.11025210)
文摘Based on the time-dependent strain cyclic characteristics and fatigue behaviors of SS304 stainless steel under multi-axial cyclic loading at 700 ？ C, and in the frame of unified visoco-plastic cyclic constitutive model and continuum damage mechanics theory, the damage-coupled multi-axial time-dependent constitutive model and fatigue failure model were proposed. In the model, the evolution equation of damage was introduced in and the time-dependent effects, e.g. holding time, loading rate, were taken into account. The model was applied to the simulation of whole-life cyclic deformation behaviors and prediction of LCF life for SS304 stainless steel in multiaxial time-dependent low cycle fatigue tests. It is shown that the simulated results agree well with experimental ones.
文摘We briefly introduce a new high-pressure transport measurement system integrated with low temperature and magnetic field that is being established as one of the user experimental stations of the Synergetic Extreme Condition User Facilities in the Huairou District of Beijing, China. To demonstrate the capabilities of the system for condensed matter research, the emergence of some pressure-induced phenomena and physics related to superconductivity found previously is also introduced, and then a perspective for such an advanced high-pressure system is presented.
