While injection-induced seismicity has been widely studied,its implications for CO_(2)geological storage require reevaluation due to distinct fluid-rock interactions.This study develops a coupled hydromechanical model...While injection-induced seismicity has been widely studied,its implications for CO_(2)geological storage require reevaluation due to distinct fluid-rock interactions.This study develops a coupled hydromechanical model incorporating rate-and-state friction laws to investigate fault reactivation mechanisms during early-stage CO_(2)injection.The competing effects of pore pressure diffusion and fluid pressurization are systematically investigated,considering three key factors:permeability variations within fault damage zones,normal stress variation coefficients,and injection parameters.Numerical simulations reveal that slower CO_(2)migration causes limited pressure perturbation(<0.3 MPa over 15 d)compared to single-phase fluid injection.Fluid pressurization enhances fault strength and delays reactivation,though this stabilizing effect diminishes in low-permeability damage zones.Highly permeable damage zones promote larger rupture areas despite strengthening from pressurization,as reduced effective stress accelerates failure.Paradoxically,while fluid pressurization increases fault strength,it simultaneously elevates seismic risk through amplified stress drops during slip events.Temporal analysis shows that fluid pressurization dominates initial fault response,while sustained pore pressure diffusion ultimately drives reactivation.Increased normal stress variation coefficients and injection rates accelerate localized rupture initiation but restrict propagation due to non-critically stressed states.This discrepancy demonstrates that regions with positive Coulomb failure stress changes do not correlate well with actual slip zones.These findings highlight the critical interplay between transient pressurization effects and progressive pressure diffusion during early CO_(2)injection phases,providing crucial insights for seismic risk management in CO_(2)storage projects.展开更多
Lithium-oxygen(Li-O_(2))battery is favored among“beyond lithiumion”technologies for sustainability because of its exceptional energy density.Major impediments are the poor cycle stability and grievous capacity degra...Lithium-oxygen(Li-O_(2))battery is favored among“beyond lithiumion”technologies for sustainability because of its exceptional energy density.Major impediments are the poor cycle stability and grievous capacity degradation at high current densities.We address these issues by a“killing two birds with one stone”O_(2)-pressure protocol.It first resolves efficient O_(2) mass transport at high rates..The accelerated reaction kinetics optimizes the composition and growth pathway of discharge products.This protocol secondly achieves protection of Li anodes via densifying corrosion layers on them.Consequently,the battery delivers both ultrahigh discharge capacity(>9,000 mAh g^(-1))at 3,000 mA g^(-1) and excellent cycling stability.Under a dual-strategy effect of high-pressure O_(2) and artificial protection layers,the battery actualizes over 11-fold increase in cycle life of 5,170 h(2,585 cycles).The strategy opens avenues for advancing Li-O_(2) batteries towards practical application and confers the extension to other gas-based batteries.展开更多
Objective To explore the effects of sliding-cup with different parameters on energy metabolism in the body by observing the effect of sliding-cup along the governor vessel on transcutaneous partial pressures of oxygen...Objective To explore the effects of sliding-cup with different parameters on energy metabolism in the body by observing the effect of sliding-cup along the governor vessel on transcutaneous partial pressures of oxygen and carbon dioxide in Mìngmén（命门 GV 4） in sub-healthy people. Methods A total of 10 sub-healthy adults at rest were observed and sliding-cup along the governor vessel were conducted with three different parameters, jar-pressure of –0.01~ –0.02 MPa with sliding-cup for 5 min, jar-pressure of –0.02~ –0.03 MPa with sliding-cup for 5 min and jar-pressure of –0.02~ –0.03 MPa with slidingcup for 3 min. Peri Flux System5000 PF5040 module was employed to monitor the changes of transcutaneous partial pressures of oxygen（tcp O2） and carbon dioxide（tcp CO2） in GV 4 at 0 min, 5 min, 10 min, 15 min, 20 min, 25 min and 30 min after sliding-cup with above different interventions in sub-healthy subjects. Results After sliding-cup, tcp O2 increased at first and then decreased over time; there was no difference in tcp O2 after sliding-cupping with different parameters（all P0.05）. After sliding-cup, tcp CO2 decreased; there was no difference in tcp CO2 after sliding-cup with different parameters（all P0.05）. Conclusion Sliding-cup has a sustained effect on the body and can speed up the energy metabolism in the body.展开更多
The interplay between electronic topological phase transitions and superconductivity in the field of condensed matter physics has consistently captivated researchers.Here we have succeeded in modulating the Lifshitz t...The interplay between electronic topological phase transitions and superconductivity in the field of condensed matter physics has consistently captivated researchers.Here we have succeeded in modulating the Lifshitz transition by pressure and realized superconductivity.At 25.7 GPa,superconductivity with a transition temperature of 1.9 K has been observed in 3R-NbS_(2).The Hall coefficient changes from negative to positive at 14 GPa,indicating a Lifshitz transition in 3R-NbS_(2),and the carrier concentration continues to increase with increasing pressure.X-ray diffraction results indicate that the appearance of superconductivity cannot be attributable to structural transitions.Based on theoretical calculations,the emergence of a new band is attributed to the Lifshitz transition and the new band coincides with the Fermi surface at the pressure of 30 GPa.These findings provide new insights into the relationship between the Lifshitz transition and superconductivity.展开更多
This study systematically investigates the transport and point-contact Andreev reflection spectroscopy(PCARS) properties of Bi-doped BaFe_(2)(As_(1-x)Bi_(x))_(2) crystals under high pressures up to 8.7 GPa. The superc...This study systematically investigates the transport and point-contact Andreev reflection spectroscopy(PCARS) properties of Bi-doped BaFe_(2)(As_(1-x)Bi_(x))_(2) crystals under high pressures up to 8.7 GPa. The superconducting critical temperature(T_(c)) and upper critical field(H_(c2)) initially decrease with pressure but exhibit a local maximum around 2.9 GPa before further suppression, which can be related to the superconducting transition in the parent compound. The conductance spectrum is consistent with a two-band s-wave model, confirming multi-band superconductivity. The superconducting energy gaps and coupling strengths decrease monotonically with pressure, with the larger gap transitioning from strong to weak coupling. These results provide insight into the interplay between structural, electronic, and superconducting properties in isovalent-doped 122 Fe-based superconductors.展开更多
The structural phase transition of MnO_(2) nanorods was investigated using in situ high pressure synchrotron x-ray diffraction(XRD) and transmission electron microscopy(TEM). At pressures exceeding 10.9 GPa, a second-...The structural phase transition of MnO_(2) nanorods was investigated using in situ high pressure synchrotron x-ray diffraction(XRD) and transmission electron microscopy(TEM). At pressures exceeding 10.9 GPa, a second-order structural phase transition from tetragonal to orthogonal, which was accompanied by fine-scale crystal twinning phenomena, was observed in MnO_(2) nanorods. On account of the significant contribution of surface energy, the phase transition pressure exhibited appreciable hysteresis compared with the bulk counterparts, suggesting the enhanced structural stability of nanorod morphology. These findings reveal that the size and morphology exhibit a manifest correlation with the high pressure behavior of MnO_(2) nanomaterials, providing useful insights into the intricate interplay between structure and properties.展开更多
BACKGROUND Negative pressure wound therapy(NPWT)is a potential treatment for diabetic foot ulcers(DFUs),although the mechanisms underlying its effectiveness remain unclear.This study posits that NPWT may improve wound...BACKGROUND Negative pressure wound therapy(NPWT)is a potential treatment for diabetic foot ulcers(DFUs),although the mechanisms underlying its effectiveness remain unclear.This study posits that NPWT may improve wound healing by promoting angiogenesis and activating the nuclear factor erythroid 2-related factor 2(Nrf2)/Kelch-like epichlorohydrin-associated protein 1(Keap1)signaling pathway,which is crucial for the body’s defense against oxidative stress.The hypothesis indicates that enhancing antioxidant defenses through NPWT may positively affect the healing process.There are still limited data on the roles of Nrf2,its downstream signaling molecules,and angiogenesis markers in patients undergoing NPWT.AIM To study the mechanism of NPWT in DFUs.METHODS This study included a total of 40 hospitalized patients with DFUs from Xuzhou Central Hospital,who were divided into Control group(n=21)and NPWT group(n=19).The levels of Nrf2 and Keap1 were analyzed in the granulation tissue 7 days after treatment.The wound condition,erythrocyte sedimentation rate(ESR),procalcitonin(PCT),interleukin 6(IL-6),tumor necrosis factor alpha(TNF-α),vascular endothelial growth factor(VEGF),basic fibroblast growth factor(b-FGF),cluster of differentiation 31(CD31),and levels of oxidative stress[malondialdehyde(MDA),superoxide dismutase(SOD),catalase(CAT),and total antioxidant capacity(T-AOC)]were analyzed before and 7 days after treatment by the Mann-Whitney U test.RESULTS The NPWT group demonstrated significant improvements in wound healing compared to the control group after 7 days of treatment.The levels of ESR,PCT,IL-6,and TNF-αwere significantly reduced in the NPWT group compared to the control group(P<0.05),while the levels of CD31,VEGF,and b-FGF showed significant increases(P<0.05).The NPWT group exhibited notable elevations in the levels of Nrf2 and its downstream targets(SOD,CAT,and T-AOC),accompanied by decreases in the levels of Keap1 and MDA(P<0.05).CONCLUSION NPWT may contribute to the healing of DFUs by potentially reducing levels of oxidative stress.Its effects could possibly be enhanced through the action of Nrf2.展开更多
Background The co-existence of Type 2 diabetes mellitus(T2DM)and hypertension presents a significant clinical challenge due to their synergistic detrimental effects on cardiovascular outcomes.Conventional combination ...Background The co-existence of Type 2 diabetes mellitus(T2DM)and hypertension presents a significant clinical challenge due to their synergistic detrimental effects on cardiovascular outcomes.Conventional combination therapies often fall short in comprehensively addressing the intertwined pathophysiologies,particularly vascular endothelial dysfunction.This study aimed to evaluate the efficacy of a novel regimen combining sitagliptin-metformin with nifedipine in managing blood pressure,blood glucose,and vascular function in this high-risk population.Methods 150 patients with T2DM and hypertension were randomly assigned to either the control group(n=75)treated with metformin and nifedipine,or the experimental group(n=75)treated with sitagliptin-metformin compound preparation combined with nifedipine.Changes in blood pressure,blood glucose levels,flow-mediated dilation(FMD)and nitroglycerin-mediated dilation(NMD)of the brachial artery,and serum levels of biomarkers[nitric oxide(NO),endothelin-1(ET-1)]were compared before and after treatment.The incidence of adverse reactions during treatment was also monitored.Results After treatment,both groups showed significant reductions in blood pressure,blood glucose parameters,and ET-1 levels compared to baseline.The experimental group demonstrated significantly lower values in these assessments at the same time points than control group(P<0.05).Conversely,FMD,NMD,and NO levels increased significantly in both groups after treatment,with experimental group showing significantly higher values than control group(P<0.05).There was no statistically significant difference in the incidence of adverse reactions between the two groups(P>0.05).Conclusions The combination of sitagliptinmetformin compound preparation and nifedipine significantly enhanced blood pressure control and blood glucose control and exerted a positive regulatory effect on vascular endothelial function in patients with T2DM and hypertension,demonstrating high clinical value for widespread application.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
As an extreme physical condition,high pressure serves as a potent means to substantially modify the interatomic distances and bonding patterns within condensed matter,thereby enabling the macroscopic manipulation of m...As an extreme physical condition,high pressure serves as a potent means to substantially modify the interatomic distances and bonding patterns within condensed matter,thereby enabling the macroscopic manipulation of material properties.We employed the CALYPSO method to predict the stable structures of RbB_(2)C_(4)across the pressure range from 0 GPa to 100 GPa and investigated its physical properties through first-principles calculations.Specially,we found four novel structures,namely,P6_(3)/mcm-,Amm2-,P1-,and I4/mmm-RbB_(2)C_(4).Under pressure conditions,electronic structure calculations reveal that all of them exhibit metallic characteristics.The calculation results of formation enthalpy show that the P6_(3)/mcm structure can be synthesized within the pressure range of 0–40 GPa.Specially,the Amm2,P1,and I4/mmm structures can be synthesized above 4 GPa,6 GPa,10 GPa,respectively.Moreover,the estimated Vickers hardness value of I4/mmm-RbB_(2)C_(4)compound is 47 GPa,suggesting that it is a superhard material.Interestingly,this study uncovers the continuous transformation of the crystal structure of RbB_(2)C_(4)from a layered configuration to folded and tubular forms,ultimately attaining a stabilized cage-like structure under the pressure span of 0–100 GPa.The application of pressure offers a formidable impetus for the advancement and innovation in condensed matter physics,facilitating the exploration of novel states and functions of matter.展开更多
El Niño-Southern Oscillation(ENSO)affects the changes in ocean physical elements in Taiwan Strait(TWS)primarily by regulating the strength of the East Asian Winter Monsoon(EAWM)and the intrusion of the Kuroshio.A...El Niño-Southern Oscillation(ENSO)affects the changes in ocean physical elements in Taiwan Strait(TWS)primarily by regulating the strength of the East Asian Winter Monsoon(EAWM)and the intrusion of the Kuroshio.Additionally,the fluctuating impact between nutrient-poor seawater with high dissolved inorganic carbon(DIC)that infiltrates owing to the Kuroshio during El Niño phases and nutrient-rich seawater with low DIC from the South China Sea(SCS)carried by the EAWM during La Niña phases determines the nutrient content in TWS,thereby sculpting appropriate or unsuitable biochemical environment.In this study,based on high-resolution sea-surface partial pressure of carbon dioxide(pCO_(2))data,we investigate the relationship between pCO_(2)level of TWS and ENSO events in winter.The physical mechanisms affecting the anomalous distribution of pCO_(2)level during ENSO are also explored.Stepwise regression was employed to identify the optimal influencing factors for modeling pCO_(2).Results indicate a significant positive correlation between Niño3.4 index and pCO_(2),which is significantly influenced by factors such as sea-surface temperature(SST),chlorophyll-a(Chl a),and DIC.These are related to the anomalously strong Kuroshio intrusion and weaker EAWM during El Niño years.It brings a large amount of high SST water with low nutrient concentration and high DIC,which is detrimental to CO_(2)dissolution and phytoplankton growth over the TWS,leading to an increase in pCO_(2).Conversely,pCO_(2)level is significantly low under the influence of SCS seawater during La Niña years.Based on the characterization of the pCO_(2)level response to ENSO,the carbon balance at TWS can be explored.展开更多
Wearable pressure sensors capable of adhering comfortably to the skin hold great promise in sound detection.However,current intelligent speech assistants based on pressure sensors can only recognize standard languages...Wearable pressure sensors capable of adhering comfortably to the skin hold great promise in sound detection.However,current intelligent speech assistants based on pressure sensors can only recognize standard languages,which hampers effective communication for non-standard language people.Here,we prepare an ultralight Ti_(3)C_(2)T_(x)MXene/chitosan/polyvinylidene difluoride composite aerogel with a detection range of 6.25 Pa-1200 k Pa,rapid response/recovery time,and low hysteresis(13.69%).The wearable aerogel pressure sensor can detect speech information through the throat muscle vibrations without any interference,allowing for accurate recognition of six dialects(96.2%accuracy)and seven different words(96.6%accuracy)with the assistance of convolutional neural networks.This work represents a significant step forward in silent speech recognition for human–machine interaction and physiological signal monitoring.展开更多
The stress corrosion cracking （SCC） behavior of welded X80 pipeline steel in simulated Ku＇erle soil solution was studied by means of electrochemical impedance spectroscopy （EIS） and slow strain rate tests （SSRT...The stress corrosion cracking （SCC） behavior of welded X80 pipeline steel in simulated Ku＇erle soil solution was studied by means of electrochemical impedance spectroscopy （EIS） and slow strain rate tests （SSRT）. The microstructure of the welded steel was observed by optical microscopy （OM）. It is demonstrated that the microstructure of the weld metal consists of acicular ferrite and grain boundary ferrite, while that of heat affected zone （HAZ） is a mixture of acicular ferrite and bainitic ferrite micro- constituents. The microstructure of the base steel is composed of ferrite and pearlite. The anodic dissolution of X80 pipeline steel in simulated Ku＇erle soil solution could be enhanced and the SCC sensitivity increased with the increase of CO2 partial pressure. The SCC mechanism of X80 pipeline is a mixing mechanism of hydrogen embrittlement combined with anodic dissolution, and the hydrogen embrittlement plays a leading role. The higher SCC sensitivity of the weld metal was attributed to the metallurgical transformation, local hardening and residual stress.展开更多
An effective parameter in the miscible-CO_2 enhanced oil recovery procedure is the minimum miscibility pressure(MMP)defined as the lowest pressure that the oil in place and the injected gas into reservoir achieve misc...An effective parameter in the miscible-CO_2 enhanced oil recovery procedure is the minimum miscibility pressure(MMP)defined as the lowest pressure that the oil in place and the injected gas into reservoir achieve miscibility at a given temperature. Flue gases released from power plants can provide an available source of CO_2,which would otherwise be emitted to the atmosphere, for injection into a reservoir. However, the costs related to gas extraction from flue gases is potentially high. Hence, greater understanding the role of impurities in miscibility characteristics between CO_2 and reservoir fluids helps to establish which impurities are tolerable and which are not. In this study, we simulate the effects of the impurities nitrogen(N_2), methane(C_1), ethane(C_2) and propane(C_3) on CO_2 MMP. The simulation results reveal that,as an impurity, nitrogen increases CO_2–oil MMP more so than methane. On the other hand, increasing the propane(C_3)content can lead to a significant decrease in CO_2 MMP, whereas varying the concentrations of ethane(C_2) does not have a significant effect on the minimum miscibility pressure of reservoir crude oil and CO_2 gas. The novel relationships established are particularly valuable in circumstances where MMP experimental data are not available.展开更多
Carbon dioxide （CO2） removal is an essential step in natural gas （NG） processing to provide high quality gas stream products and minimize operational difficulties. This preliminary study alms to investigate the re...Carbon dioxide （CO2） removal is an essential step in natural gas （NG） processing to provide high quality gas stream products and minimize operational difficulties. This preliminary study alms to investigate the removal of CO2 at high concentration level from the mixture of CO2-NG gas stream at elevated pressure via absorption process. This is to explore the possibility of exploring high CO2 content natural gas reserves by treatment at offshore platform. A mixed amine solvent, Stonvent-II, was used for the absorption of approximately 75 vol% CO2 in CO2-NG stream at a pressure of 10 barg. The initial solvent temperature was varied in order to study the impact of initial temperature on the absorption performance. Preliminary study at temperatures of 35 ℃ and 45 ℃ indicates that Stonvent-II was able to perform almost 100% removal of CO2 under both conditions. However, the CO2 absorption effect took place faster when the initial liquid temperature was lower. This is because when the initial liquid temperature is high, the temperature increase in the packing bed caused by the reaction heat is high which impacts the efficiency of absorption negatively.展开更多
The thermal decomposition of 2, 2'-azobis (isobutyronitrile) (AIBN) in supercritical CO2 with cosolvent methanol or cyclohexane has been studied by using UV/Vis spectroscopic method at 335.15 K and at 12.0 MPa and...The thermal decomposition of 2, 2'-azobis (isobutyronitrile) (AIBN) in supercritical CO2 with cosolvent methanol or cyclohexane has been studied by using UV/Vis spectroscopic method at 335.15 K and at 12.0 MPa and 14.0 MPa. Both of the cosolvents can accelerate the decomposition rate, and the effect of methanol is more significant than that of the cyclohexane.展开更多
We systematically investigate the effect of pressure on the magnetic properties of GdCo2B2 on the basis of alternating current（AC） susceptibility,AC heat capacity and electrical resistivity measurements under pressu...We systematically investigate the effect of pressure on the magnetic properties of GdCo2B2 on the basis of alternating current（AC） susceptibility,AC heat capacity and electrical resistivity measurements under pressures up to 2.2 GPa.A detailed magnetic phase diagram under pressure is determined.GdCo2B2 exhibits three anomalies that apparently reflect magnetic phase transitions,respectively,at temperatures TC= 20.5 K,T1= 18.0 K and TN= 11.5 K under ambient pressure.Under pressures up to 2.2 GPa,these anomalies are observed to slightly increase at TCand T1,and they coincide with each other above 1.6 GPa.Conversely,they decrease at TN and disappear under pressures higher than 1.4 GPa.The results indicate that the low-temperature magnetic phases can be easily suppressed by pressure.Moreover,the spin-glass-like behavior of GdCo2B2 is examined in terms of magnetization,aging effect and frequency dependence of AC susceptibility.A separation between the zero-field-cooled（ZFC） and field-cooled（FC） magnetization curves becomes evident at a low magnetic field of 0.001 T.A long-time relaxation behavior is observed at 4 K.The freezing temperature Tfincreases with frequency increasing.展开更多
High-pressure phase behavior of supercritical (SC) CO2+ethanol system was investigated at 333.2 K,348.2K, 353.2K, 368.2K, 413.2K and 453.2K and pressure from 2.0MPa to 14.3MPa. The measurement was carried out in a cy...High-pressure phase behavior of supercritical (SC) CO2+ethanol system was investigated at 333.2 K,348.2K, 353.2K, 368.2K, 413.2K and 453.2K and pressure from 2.0MPa to 14.3MPa. The measurement was carried out in a cylindrical autoclave with a moveable piston and a window for adjustment and observation of phase equilibria at given T and p. The samples were taken from two coexisting phases and were analyzed to obtain their compositions. It is shown that the solubility of SC CO2 in ethanol increases drastically with pressures at the given temperature, but the content of ethanol in CO2-rich phase increase faintly.展开更多
Reactions between CH_4 and CO_2 under the action of continuous microwave discharge at atmospheric pressure were studied in a special homemade reactor. The main products were CO and H2, while acetylene and ethylene wer...Reactions between CH_4 and CO_2 under the action of continuous microwave discharge at atmospheric pressure were studied in a special homemade reactor. The main products were CO and H2, while acetylene and ethylene were also found in the products. Experimental results show that conversions of CH4 and CO2 could be higher than 90% without the presence of any catalyst. Effects of CO2/CH4 molar ratio and total flow rate of the feed gas on the reaction were also investigated.展开更多
To analyze the thermodynamic characteristics of leaching process of converter slag, φ-pH diagram of V-Ti-H2O system at oxygen partial pressure of 0.5 MPa, ionic mass concentration of 0.1 mol/kg and temperatures rangi...To analyze the thermodynamic characteristics of leaching process of converter slag, φ-pH diagram of V-Ti-H2O system at oxygen partial pressure of 0.5 MPa, ionic mass concentration of 0.1 mol/kg and temperatures ranging from 60 to 200 ℃ was obtained by recently published critically assessed standard Gibbs energies and activity coefficients of various species. When pH2, stable regions of V3＋, VO2＋ and VO2＋ exist in the stable region of TiO2. The pH values of stable regions of vanadium and titanium decrease and redox potentials become more positive with the temperature increasing. Vanadium and titanium could be separated by one-step leaching based on thermodynamics. The experiment results of pressure acid leaching of converter slag show that leaching rates of vanadium and titanium are 96.87% and 8.76% respectively, at 140 ℃ of temperature, 0.5 MPa of oxygen partial pressure, 0.055-0.075mm of particle size, 15：1 of liquid to solid ratio, 120 min of leaching time, 500 r/min of stirring speed and 200 g/L of initial acid concentration. Vanadium and titanium could be selectively separated in the pressure acid leaching process, and the experiment result is in agreement with thermodynamic calculation result.展开更多
基金funded by Joint Funds of the National Natural Science Foundation of China(Grant No.U23A20671)the Major Project of Inner Mongolia Science and Technology(Grant No.2021ZD0034)the Creative Groups of Natural Science Foundation of Hubei Province,China(Grant No.2021CFA030).
文摘While injection-induced seismicity has been widely studied,its implications for CO_(2)geological storage require reevaluation due to distinct fluid-rock interactions.This study develops a coupled hydromechanical model incorporating rate-and-state friction laws to investigate fault reactivation mechanisms during early-stage CO_(2)injection.The competing effects of pore pressure diffusion and fluid pressurization are systematically investigated,considering three key factors:permeability variations within fault damage zones,normal stress variation coefficients,and injection parameters.Numerical simulations reveal that slower CO_(2)migration causes limited pressure perturbation(<0.3 MPa over 15 d)compared to single-phase fluid injection.Fluid pressurization enhances fault strength and delays reactivation,though this stabilizing effect diminishes in low-permeability damage zones.Highly permeable damage zones promote larger rupture areas despite strengthening from pressurization,as reduced effective stress accelerates failure.Paradoxically,while fluid pressurization increases fault strength,it simultaneously elevates seismic risk through amplified stress drops during slip events.Temporal analysis shows that fluid pressurization dominates initial fault response,while sustained pore pressure diffusion ultimately drives reactivation.Increased normal stress variation coefficients and injection rates accelerate localized rupture initiation but restrict propagation due to non-critically stressed states.This discrepancy demonstrates that regions with positive Coulomb failure stress changes do not correlate well with actual slip zones.These findings highlight the critical interplay between transient pressurization effects and progressive pressure diffusion during early CO_(2)injection phases,providing crucial insights for seismic risk management in CO_(2)storage projects.
基金support from the Major basic research project of Natural Science Foundation of Shandong Province(No.ZR2023ZD12)Singapore National Research Foundation Investigatorship(No.NRFNRFI08-2022-0009)NUS R&G Postdoc Fellowship Program.
文摘Lithium-oxygen(Li-O_(2))battery is favored among“beyond lithiumion”technologies for sustainability because of its exceptional energy density.Major impediments are the poor cycle stability and grievous capacity degradation at high current densities.We address these issues by a“killing two birds with one stone”O_(2)-pressure protocol.It first resolves efficient O_(2) mass transport at high rates..The accelerated reaction kinetics optimizes the composition and growth pathway of discharge products.This protocol secondly achieves protection of Li anodes via densifying corrosion layers on them.Consequently,the battery delivers both ultrahigh discharge capacity(>9,000 mAh g^(-1))at 3,000 mA g^(-1) and excellent cycling stability.Under a dual-strategy effect of high-pressure O_(2) and artificial protection layers,the battery actualizes over 11-fold increase in cycle life of 5,170 h(2,585 cycles).The strategy opens avenues for advancing Li-O_(2) batteries towards practical application and confers the extension to other gas-based batteries.
基金Suported by Tianjin Municipal Administration of Traditional Chinese Medicine:11028
文摘Objective To explore the effects of sliding-cup with different parameters on energy metabolism in the body by observing the effect of sliding-cup along the governor vessel on transcutaneous partial pressures of oxygen and carbon dioxide in Mìngmén（命门 GV 4） in sub-healthy people. Methods A total of 10 sub-healthy adults at rest were observed and sliding-cup along the governor vessel were conducted with three different parameters, jar-pressure of –0.01~ –0.02 MPa with sliding-cup for 5 min, jar-pressure of –0.02~ –0.03 MPa with sliding-cup for 5 min and jar-pressure of –0.02~ –0.03 MPa with slidingcup for 3 min. Peri Flux System5000 PF5040 module was employed to monitor the changes of transcutaneous partial pressures of oxygen（tcp O2） and carbon dioxide（tcp CO2） in GV 4 at 0 min, 5 min, 10 min, 15 min, 20 min, 25 min and 30 min after sliding-cup with above different interventions in sub-healthy subjects. Results After sliding-cup, tcp O2 increased at first and then decreased over time; there was no difference in tcp O2 after sliding-cupping with different parameters（all P0.05）. After sliding-cup, tcp CO2 decreased; there was no difference in tcp CO2 after sliding-cup with different parameters（all P0.05）. Conclusion Sliding-cup has a sustained effect on the body and can speed up the energy metabolism in the body.
基金Project supported by the National Key R&D Program of China(Grant No.2022YFA1405500)the National Natural Science Foundation of China(Grant Nos.52072188 and 12304072)+1 种基金Program for Science and Technology Innovation Team in Zhejiang(Grant No.2021R01004)the Natural Science Foundation of Ningbo(Grant No.2021J121)。
文摘The interplay between electronic topological phase transitions and superconductivity in the field of condensed matter physics has consistently captivated researchers.Here we have succeeded in modulating the Lifshitz transition by pressure and realized superconductivity.At 25.7 GPa,superconductivity with a transition temperature of 1.9 K has been observed in 3R-NbS_(2).The Hall coefficient changes from negative to positive at 14 GPa,indicating a Lifshitz transition in 3R-NbS_(2),and the carrier concentration continues to increase with increasing pressure.X-ray diffraction results indicate that the appearance of superconductivity cannot be attributable to structural transitions.Based on theoretical calculations,the emergence of a new band is attributed to the Lifshitz transition and the new band coincides with the Fermi surface at the pressure of 30 GPa.These findings provide new insights into the relationship between the Lifshitz transition and superconductivity.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 12461160274 and 12004104)Shenzhen Fundamental Research Program (Grant No. JCYJ20230807093301003)+1 种基金the Major Science and Technology Infrastructure Project of Material Genome Big-science Facilities Platform supported by Municipal Development and Reform Commission of Shenzhensupported by Guangdong Provincial Quantum Science Strategic Initiative (Grant No. GDZX2201001)。
文摘This study systematically investigates the transport and point-contact Andreev reflection spectroscopy(PCARS) properties of Bi-doped BaFe_(2)(As_(1-x)Bi_(x))_(2) crystals under high pressures up to 8.7 GPa. The superconducting critical temperature(T_(c)) and upper critical field(H_(c2)) initially decrease with pressure but exhibit a local maximum around 2.9 GPa before further suppression, which can be related to the superconducting transition in the parent compound. The conductance spectrum is consistent with a two-band s-wave model, confirming multi-band superconductivity. The superconducting energy gaps and coupling strengths decrease monotonically with pressure, with the larger gap transitioning from strong to weak coupling. These results provide insight into the interplay between structural, electronic, and superconducting properties in isovalent-doped 122 Fe-based superconductors.
基金Project supported by China Postdoctoral Science Foundation (Grant No. 2023M742049)Guangdong Basic and Applied Basic Research Foundation (Grant No. 2023A1515110844)the Innovative Training Program for College Students (Grant No. 20249076)。
文摘The structural phase transition of MnO_(2) nanorods was investigated using in situ high pressure synchrotron x-ray diffraction(XRD) and transmission electron microscopy(TEM). At pressures exceeding 10.9 GPa, a second-order structural phase transition from tetragonal to orthogonal, which was accompanied by fine-scale crystal twinning phenomena, was observed in MnO_(2) nanorods. On account of the significant contribution of surface energy, the phase transition pressure exhibited appreciable hysteresis compared with the bulk counterparts, suggesting the enhanced structural stability of nanorod morphology. These findings reveal that the size and morphology exhibit a manifest correlation with the high pressure behavior of MnO_(2) nanomaterials, providing useful insights into the intricate interplay between structure and properties.
文摘BACKGROUND Negative pressure wound therapy(NPWT)is a potential treatment for diabetic foot ulcers(DFUs),although the mechanisms underlying its effectiveness remain unclear.This study posits that NPWT may improve wound healing by promoting angiogenesis and activating the nuclear factor erythroid 2-related factor 2(Nrf2)/Kelch-like epichlorohydrin-associated protein 1(Keap1)signaling pathway,which is crucial for the body’s defense against oxidative stress.The hypothesis indicates that enhancing antioxidant defenses through NPWT may positively affect the healing process.There are still limited data on the roles of Nrf2,its downstream signaling molecules,and angiogenesis markers in patients undergoing NPWT.AIM To study the mechanism of NPWT in DFUs.METHODS This study included a total of 40 hospitalized patients with DFUs from Xuzhou Central Hospital,who were divided into Control group(n=21)and NPWT group(n=19).The levels of Nrf2 and Keap1 were analyzed in the granulation tissue 7 days after treatment.The wound condition,erythrocyte sedimentation rate(ESR),procalcitonin(PCT),interleukin 6(IL-6),tumor necrosis factor alpha(TNF-α),vascular endothelial growth factor(VEGF),basic fibroblast growth factor(b-FGF),cluster of differentiation 31(CD31),and levels of oxidative stress[malondialdehyde(MDA),superoxide dismutase(SOD),catalase(CAT),and total antioxidant capacity(T-AOC)]were analyzed before and 7 days after treatment by the Mann-Whitney U test.RESULTS The NPWT group demonstrated significant improvements in wound healing compared to the control group after 7 days of treatment.The levels of ESR,PCT,IL-6,and TNF-αwere significantly reduced in the NPWT group compared to the control group(P<0.05),while the levels of CD31,VEGF,and b-FGF showed significant increases(P<0.05).The NPWT group exhibited notable elevations in the levels of Nrf2 and its downstream targets(SOD,CAT,and T-AOC),accompanied by decreases in the levels of Keap1 and MDA(P<0.05).CONCLUSION NPWT may contribute to the healing of DFUs by potentially reducing levels of oxidative stress.Its effects could possibly be enhanced through the action of Nrf2.
文摘Background The co-existence of Type 2 diabetes mellitus(T2DM)and hypertension presents a significant clinical challenge due to their synergistic detrimental effects on cardiovascular outcomes.Conventional combination therapies often fall short in comprehensively addressing the intertwined pathophysiologies,particularly vascular endothelial dysfunction.This study aimed to evaluate the efficacy of a novel regimen combining sitagliptin-metformin with nifedipine in managing blood pressure,blood glucose,and vascular function in this high-risk population.Methods 150 patients with T2DM and hypertension were randomly assigned to either the control group(n=75)treated with metformin and nifedipine,or the experimental group(n=75)treated with sitagliptin-metformin compound preparation combined with nifedipine.Changes in blood pressure,blood glucose levels,flow-mediated dilation(FMD)and nitroglycerin-mediated dilation(NMD)of the brachial artery,and serum levels of biomarkers[nitric oxide(NO),endothelin-1(ET-1)]were compared before and after treatment.The incidence of adverse reactions during treatment was also monitored.Results After treatment,both groups showed significant reductions in blood pressure,blood glucose parameters,and ET-1 levels compared to baseline.The experimental group demonstrated significantly lower values in these assessments at the same time points than control group(P<0.05).Conversely,FMD,NMD,and NO levels increased significantly in both groups after treatment,with experimental group showing significantly higher values than control group(P<0.05).There was no statistically significant difference in the incidence of adverse reactions between the two groups(P>0.05).Conclusions The combination of sitagliptinmetformin compound preparation and nifedipine significantly enhanced blood pressure control and blood glucose control and exerted a positive regulatory effect on vascular endothelial function in patients with T2DM and hypertension,demonstrating high clinical value for widespread application.
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Project supported by the Jilin Provincial Science and Technology Development Joint Fund Project(Grant No.YDZJ202201ZYTS581)supported by the Scientific and Technological Research Project of Jilin Provincial Education Department(Grant No.JJKH20240077KJ).
文摘As an extreme physical condition,high pressure serves as a potent means to substantially modify the interatomic distances and bonding patterns within condensed matter,thereby enabling the macroscopic manipulation of material properties.We employed the CALYPSO method to predict the stable structures of RbB_(2)C_(4)across the pressure range from 0 GPa to 100 GPa and investigated its physical properties through first-principles calculations.Specially,we found four novel structures,namely,P6_(3)/mcm-,Amm2-,P1-,and I4/mmm-RbB_(2)C_(4).Under pressure conditions,electronic structure calculations reveal that all of them exhibit metallic characteristics.The calculation results of formation enthalpy show that the P6_(3)/mcm structure can be synthesized within the pressure range of 0–40 GPa.Specially,the Amm2,P1,and I4/mmm structures can be synthesized above 4 GPa,6 GPa,10 GPa,respectively.Moreover,the estimated Vickers hardness value of I4/mmm-RbB_(2)C_(4)compound is 47 GPa,suggesting that it is a superhard material.Interestingly,this study uncovers the continuous transformation of the crystal structure of RbB_(2)C_(4)from a layered configuration to folded and tubular forms,ultimately attaining a stabilized cage-like structure under the pressure span of 0–100 GPa.The application of pressure offers a formidable impetus for the advancement and innovation in condensed matter physics,facilitating the exploration of novel states and functions of matter.
基金The Key R&D Project of Zhejiang Province under contract No.2023C03120the General Scientific Research Project of Zhejiang Province under contract No.Y202353957the National Natural Science Foundation of China under contract No.42106017.
文摘El Niño-Southern Oscillation(ENSO)affects the changes in ocean physical elements in Taiwan Strait(TWS)primarily by regulating the strength of the East Asian Winter Monsoon(EAWM)and the intrusion of the Kuroshio.Additionally,the fluctuating impact between nutrient-poor seawater with high dissolved inorganic carbon(DIC)that infiltrates owing to the Kuroshio during El Niño phases and nutrient-rich seawater with low DIC from the South China Sea(SCS)carried by the EAWM during La Niña phases determines the nutrient content in TWS,thereby sculpting appropriate or unsuitable biochemical environment.In this study,based on high-resolution sea-surface partial pressure of carbon dioxide(pCO_(2))data,we investigate the relationship between pCO_(2)level of TWS and ENSO events in winter.The physical mechanisms affecting the anomalous distribution of pCO_(2)level during ENSO are also explored.Stepwise regression was employed to identify the optimal influencing factors for modeling pCO_(2).Results indicate a significant positive correlation between Niño3.4 index and pCO_(2),which is significantly influenced by factors such as sea-surface temperature(SST),chlorophyll-a(Chl a),and DIC.These are related to the anomalously strong Kuroshio intrusion and weaker EAWM during El Niño years.It brings a large amount of high SST water with low nutrient concentration and high DIC,which is detrimental to CO_(2)dissolution and phytoplankton growth over the TWS,leading to an increase in pCO_(2).Conversely,pCO_(2)level is significantly low under the influence of SCS seawater during La Niña years.Based on the characterization of the pCO_(2)level response to ENSO,the carbon balance at TWS can be explored.
基金supported by the National Nature Science Foundation of China(No.62122030,62333008,62371205,52103208)National Key Research and Development Program of China(No.2021YFB3201300)+1 种基金Application and Basic Research of Jilin Province(20130102010 JC)Fundamental Research Funds for the Central Universities,Jilin Provincial Science and Technology Development Program(20230101072JC)。
文摘Wearable pressure sensors capable of adhering comfortably to the skin hold great promise in sound detection.However,current intelligent speech assistants based on pressure sensors can only recognize standard languages,which hampers effective communication for non-standard language people.Here,we prepare an ultralight Ti_(3)C_(2)T_(x)MXene/chitosan/polyvinylidene difluoride composite aerogel with a detection range of 6.25 Pa-1200 k Pa,rapid response/recovery time,and low hysteresis(13.69%).The wearable aerogel pressure sensor can detect speech information through the throat muscle vibrations without any interference,allowing for accurate recognition of six dialects(96.2%accuracy)and seven different words(96.6%accuracy)with the assistance of convolutional neural networks.This work represents a significant step forward in silent speech recognition for human–machine interaction and physiological signal monitoring.
基金supported by the National Natural Science Foundation of China (No.50771053)
文摘The stress corrosion cracking （SCC） behavior of welded X80 pipeline steel in simulated Ku＇erle soil solution was studied by means of electrochemical impedance spectroscopy （EIS） and slow strain rate tests （SSRT）. The microstructure of the welded steel was observed by optical microscopy （OM）. It is demonstrated that the microstructure of the weld metal consists of acicular ferrite and grain boundary ferrite, while that of heat affected zone （HAZ） is a mixture of acicular ferrite and bainitic ferrite micro- constituents. The microstructure of the base steel is composed of ferrite and pearlite. The anodic dissolution of X80 pipeline steel in simulated Ku＇erle soil solution could be enhanced and the SCC sensitivity increased with the increase of CO2 partial pressure. The SCC mechanism of X80 pipeline is a mixing mechanism of hydrogen embrittlement combined with anodic dissolution, and the hydrogen embrittlement plays a leading role. The higher SCC sensitivity of the weld metal was attributed to the metallurgical transformation, local hardening and residual stress.
文摘An effective parameter in the miscible-CO_2 enhanced oil recovery procedure is the minimum miscibility pressure(MMP)defined as the lowest pressure that the oil in place and the injected gas into reservoir achieve miscibility at a given temperature. Flue gases released from power plants can provide an available source of CO_2,which would otherwise be emitted to the atmosphere, for injection into a reservoir. However, the costs related to gas extraction from flue gases is potentially high. Hence, greater understanding the role of impurities in miscibility characteristics between CO_2 and reservoir fluids helps to establish which impurities are tolerable and which are not. In this study, we simulate the effects of the impurities nitrogen(N_2), methane(C_1), ethane(C_2) and propane(C_3) on CO_2 MMP. The simulation results reveal that,as an impurity, nitrogen increases CO_2–oil MMP more so than methane. On the other hand, increasing the propane(C_3)content can lead to a significant decrease in CO_2 MMP, whereas varying the concentrations of ethane(C_2) does not have a significant effect on the minimum miscibility pressure of reservoir crude oil and CO_2 gas. The novel relationships established are particularly valuable in circumstances where MMP experimental data are not available.
文摘Carbon dioxide （CO2） removal is an essential step in natural gas （NG） processing to provide high quality gas stream products and minimize operational difficulties. This preliminary study alms to investigate the removal of CO2 at high concentration level from the mixture of CO2-NG gas stream at elevated pressure via absorption process. This is to explore the possibility of exploring high CO2 content natural gas reserves by treatment at offshore platform. A mixed amine solvent, Stonvent-II, was used for the absorption of approximately 75 vol% CO2 in CO2-NG stream at a pressure of 10 barg. The initial solvent temperature was varied in order to study the impact of initial temperature on the absorption performance. Preliminary study at temperatures of 35 ℃ and 45 ℃ indicates that Stonvent-II was able to perform almost 100% removal of CO2 under both conditions. However, the CO2 absorption effect took place faster when the initial liquid temperature was lower. This is because when the initial liquid temperature is high, the temperature increase in the packing bed caused by the reaction heat is high which impacts the efficiency of absorption negatively.
文摘The thermal decomposition of 2, 2'-azobis (isobutyronitrile) (AIBN) in supercritical CO2 with cosolvent methanol or cyclohexane has been studied by using UV/Vis spectroscopic method at 335.15 K and at 12.0 MPa and 14.0 MPa. Both of the cosolvents can accelerate the decomposition rate, and the effect of methanol is more significant than that of the cyclohexane.
基金Project supported by JSPS KAKENHI(Grant No.24540366,Grant-in-Aid for Scientific Research(C))
文摘We systematically investigate the effect of pressure on the magnetic properties of GdCo2B2 on the basis of alternating current（AC） susceptibility,AC heat capacity and electrical resistivity measurements under pressures up to 2.2 GPa.A detailed magnetic phase diagram under pressure is determined.GdCo2B2 exhibits three anomalies that apparently reflect magnetic phase transitions,respectively,at temperatures TC= 20.5 K,T1= 18.0 K and TN= 11.5 K under ambient pressure.Under pressures up to 2.2 GPa,these anomalies are observed to slightly increase at TCand T1,and they coincide with each other above 1.6 GPa.Conversely,they decrease at TN and disappear under pressures higher than 1.4 GPa.The results indicate that the low-temperature magnetic phases can be easily suppressed by pressure.Moreover,the spin-glass-like behavior of GdCo2B2 is examined in terms of magnetization,aging effect and frequency dependence of AC susceptibility.A separation between the zero-field-cooled（ZFC） and field-cooled（FC） magnetization curves becomes evident at a low magnetic field of 0.001 T.A long-time relaxation behavior is observed at 4 K.The freezing temperature Tfincreases with frequency increasing.
文摘High-pressure phase behavior of supercritical (SC) CO2+ethanol system was investigated at 333.2 K,348.2K, 353.2K, 368.2K, 413.2K and 453.2K and pressure from 2.0MPa to 14.3MPa. The measurement was carried out in a cylindrical autoclave with a moveable piston and a window for adjustment and observation of phase equilibria at given T and p. The samples were taken from two coexisting phases and were analyzed to obtain their compositions. It is shown that the solubility of SC CO2 in ethanol increases drastically with pressures at the given temperature, but the content of ethanol in CO2-rich phase increase faintly.
文摘Reactions between CH_4 and CO_2 under the action of continuous microwave discharge at atmospheric pressure were studied in a special homemade reactor. The main products were CO and H2, while acetylene and ethylene were also found in the products. Experimental results show that conversions of CH4 and CO2 could be higher than 90% without the presence of any catalyst. Effects of CO2/CH4 molar ratio and total flow rate of the feed gas on the reaction were also investigated.
基金Project(2007CB613504)supported by the National Key Basic Research Program of ChinaProjects(51004033,50974035,51074047)supported by the National Natural Science Foundation of ChinaProject(2008BAB34B01)supported by National Science and Technology Support Plan of China during the 11th Five-Year Plan
文摘To analyze the thermodynamic characteristics of leaching process of converter slag, φ-pH diagram of V-Ti-H2O system at oxygen partial pressure of 0.5 MPa, ionic mass concentration of 0.1 mol/kg and temperatures ranging from 60 to 200 ℃ was obtained by recently published critically assessed standard Gibbs energies and activity coefficients of various species. When pH2, stable regions of V3＋, VO2＋ and VO2＋ exist in the stable region of TiO2. The pH values of stable regions of vanadium and titanium decrease and redox potentials become more positive with the temperature increasing. Vanadium and titanium could be separated by one-step leaching based on thermodynamics. The experiment results of pressure acid leaching of converter slag show that leaching rates of vanadium and titanium are 96.87% and 8.76% respectively, at 140 ℃ of temperature, 0.5 MPa of oxygen partial pressure, 0.055-0.075mm of particle size, 15：1 of liquid to solid ratio, 120 min of leaching time, 500 r/min of stirring speed and 200 g/L of initial acid concentration. Vanadium and titanium could be selectively separated in the pressure acid leaching process, and the experiment result is in agreement with thermodynamic calculation result.
