To study the temperature distribution and thermal-stress field in different service stages, a two-dimensional model of a turbine blade with thermal barrier coatings is developed, in which the conjugate heat transfer a...To study the temperature distribution and thermal-stress field in different service stages, a two-dimensional model of a turbine blade with thermal barrier coatings is developed, in which the conjugate heat transfer analysis and the decoupled thermal-stress calculation method are adopted. Based on the simulation results, it is found that a non-uniform distribution of temperature appears in different positions of the blade surface, which has directly impacted on stress field. The maximum temperature with a value of 1030 ℃ occurs at the leading edge. During the steady stage, the maximum stress of thermally grown oxide （TGO） appears in the middle of the suction side, reaching 3.75 GPa. At the end stage of cooling, the maximum compressive stress of TGO with a value of-3.5 GPa occurs at the leading edge. Thus, it can be predicted that during the steady stage the dangerous regions may locate at the suction side, while the leadine edge mav be more Drone to failure on cooling.展开更多
Gas foil bearing faces severe and complex thermal-fluid–solid coupling issues when in ultra-high speed and miniaturized impeller machineries.In this study,a Thermo-Elasto-Hydrodynamic(TEHD)analysis of a specific mult...Gas foil bearing faces severe and complex thermal-fluid–solid coupling issues when in ultra-high speed and miniaturized impeller machineries.In this study,a Thermo-Elasto-Hydrodynamic(TEHD)analysis of a specific multi-layer gas foil thrust bearing on the continuous loading process within a steady rotational speed is numerically investigated by a three-dimensional thermal-fluid–solid coupling method.Results indicate that the multi-layer foil exhibits nonlinear overall stiffness,with the thrust bottom foil serving as the primary elastic deformation structure,while the thrust top foil maintains a well-defined aerodynamic shape during a loading process,which helps reduce frictional damage and achieve an adequate loading capacity.For low loads,the fluctuation of the gas film is extremely sensitive,and it weakens dramatically as the load increases.The viscous heating and friction torque exhibit a linear relationship with an increasing bearing load after a rapid growth.Depending on the exact stacking sequence and contact position of the multi-layer gas foil,the overlapping configuration allows for efficient transfer of viscous-shearing heat accumulated at the smallest air film through thermal conduction while providing elastic support.Due to the strong inhomogeneity of the viscous heat under varying loads,the temperature distribution on the top foil surface shows pronounced variations,while the difference between the peak and average temperatures of the thrust plate and top foil surfaces widens substantially with an increasing load.展开更多
In marine seismic exploration, ocean-bottom cable techniques accurately record the multicomponent seismic wavefield; however, the seismic wave propagation in fluid–solid media cannot be simulated by a single wave equ...In marine seismic exploration, ocean-bottom cable techniques accurately record the multicomponent seismic wavefield; however, the seismic wave propagation in fluid–solid media cannot be simulated by a single wave equation. In addition, when the seabed interface is irregular, traditional finite-difference schemes cannot simulate the seismic wave propagation across the irregular seabed interface. Therefore, an acoustic–elastic forward modeling and vector-based P-and S-wave separation method is proposed. In this method, we divide the fluid–solid elastic media with irregular interface into orthogonal grids and map the irregular interface in the Cartesian coordinates system into a horizontal interface in the curvilinear coordinates system of the computational domain using coordinates transformation. The acoustic and elastic wave equations in the curvilinear coordinates system are applied to the fluid and solid medium, respectively. At the irregular interface, the two equations are combined into an acoustic–elastic equation in the curvilinear coordinates system. We next introduce a full staggered-grid scheme to improve the stability of the numerical simulation. Thus, separate P-and S-wave equations in the curvilinear coordinates system are derived to realize the P-and S-wave separation method.展开更多
Coking at the fractionating tower bottom and the decant oil circulation system disrupts the heat balance,leading to unplanned shutdown and destroying the long period stable operation of the Fluid Catalytic Cracking Un...Coking at the fractionating tower bottom and the decant oil circulation system disrupts the heat balance,leading to unplanned shutdown and destroying the long period stable operation of the Fluid Catalytic Cracking Unit(FCCU).The FCCU operates through interconnected subsystems,generating high-dimensional,nonlinear,and non-stationary data characterized by spatiotemporally correlated.The decant oil solid content is the crucial indicator for monitoring catalyst loss from the reactor-regenerator system and coking risk tendency at the fractionating tower bottom that relies on sampling and laboratory testing,which is lagging responsiveness and labor-intensive.Developing the online decant oil solid content soft sensor using industrial data to support operators in conducting predictive maintenance is essential.Therefore,this paper proposes a hybrid deep learning framework for soft sensor development that combines spatiotemporal pattern extraction with interpretability,enabling accurate risk identification in dynamic operational conditions.This framework employs a Filter-Wrapper method for dimensionality reduction,followed by a 2D Convolutional Neural Network(2DCNN)for extracting spatial patterns,and a Bidirectional Gated Recurrent Unit(BiGRU)for capturing long-term temporal dependencies,with an Attention Mechanism(AM)to highlight critical features adaptively.The integration of SHapley Additive exPlanations(SHAP),Complementary Ensemble Empirical Mode Decomposition with Adaptive Noise(CEEMDAN),2DCNN,and expert knowledge precisely quantifies feature contributions and decomposes signals,significantly enhancing the practicality of risk identification.Applied to a China refinery with processing capacity of 2.80×10^(6) t/a,the soft sensor achieved the R^(2) value of 0.93 and five-level risk identification accuracy of 96.42%.These results demonstrate the framework's accuracy,robustness,and suitability for complex industrial scenarios,advancing risk visualization and management.展开更多
Smart low-solid drilling fluids(SLSDFs)with thermo-controllable rheological properties and attractive thickening characteristics have recently captivated profound attention due to their low formation damage and enhanc...Smart low-solid drilling fluids(SLSDFs)with thermo-controllable rheological properties and attractive thickening characteristics have recently captivated profound attention due to their low formation damage and enhanced cuttings lifting capacity.However,their applications to deep hole drilling at high temperatures have remained limited because of the thermal instability and environmental constraints of the thermo-associating polymers as additives.This work explored the synergistic benefits of thermo-associating polymer and biogenic nano-silica(B-SiNP)extracted from rice husk to improve the thermo-stability of SLSDF.This study shows that the nano-hybrid,TAP-S based on vinyl-terminated B-SiNP could potentially mitigate the limiting performance of conventional LSDF(F-2)caused by the failure of thermo-associating copolymers under elevated temperatures.TAP-S bearing drilling fluid(F-3)could preserve more than 5.6-fold of its initial properties(ca.apparent viscosity,plastic viscosity,yield point,and gel strength)with a nearly flat-gel profile in the temperature range of 25-230℃,which was higher than those of the counterpart F-2 and base fluid according to the results of rheological tests analysis.In addition,TAP-S exhibited an abrupt thermo-thickening characteristic with a magnitude declining by only 1.05-fold and the activation Gibbs free energy of 1339 kJ/mol above the plateau(ca.130℃),reflecting its less sensitivity compared to F-2 under a continuous heating process.As a result,a lower temperature was required to drive the dehydration of the residual fraction of lower critical solution temperature(LCST)in nano-hybrid structures than TAP according to the results of DSC analysis.Thus,lower energy was expected to disintegrate the residual hydrogen bonds formed between the LCST chains and surrounding water molecules at elevated temperatures.Moreover,TAP-S formed a solid-micro-crosslinking structure network which exhibited a more stable hydrodynamic diameter as revealed by DLS analysis.Compared with TAP,TAP-S consisted of a larger composite B-SiNP-TAP integrated spatial network structure based on the results of environmental scanning electron microscope,which conferred a degree of thermal conductivity characteristic for improved temperature resistance.This contributed to the effective binding onto bentonite particles for protection and maintained a relatively stable bentonite particle dispersion according to the results of EPM and particle size distribution analyses.Consequently,TAP-S fortified drilling fluid demonstrates improved rheological and filtration performance under severe downhole conditions.Therefore,TAP-S,the thermo-associating copolymer integrated with B-SiNP could find potential application as an eco-friendly viscosifier in LSDFs for deep-well drilling operations.展开更多
The application of industrial solid wastes as environmentally functional materials for air pollutants control has gained much attention in recent years due to its potential to reduce air pollution in a cost-effective ...The application of industrial solid wastes as environmentally functional materials for air pollutants control has gained much attention in recent years due to its potential to reduce air pollution in a cost-effective manner.In this review,we investigate the development of industrialwaste-based functional materials for various gas pollutant removal and consider the relevant reaction mechanism according to different types of industrial solid waste.We see a recent effort towards achieving high-performance environmental functional materials via chemical or physical modification,in which the active components,pore size,and phase structure can be altered.The review will discuss the potential of using industrial solid wastes,these modified materials,or synthesized materials from raw waste precursors for the removal of air pollutants,including SO_(2),NO_(x),Hg^(0),H_(2)S,VOCs,and CO_(2).The challenges still need to be addressed to realize this potential and the prospects for future research fully.The suggestions for future directions include determining the optimal composition of these materials,calculating the real reaction rate and turnover frequency,developing effective treatment methods,and establishing chemical component databases of raw industrial solid waste for catalysts/adsorbent preparation.展开更多
Crystal habit and crystal form are critical elements in determining product properties and functions. In this work, we developed a microfluidic antisolvent crystallization technique to rapidly screen and accurately co...Crystal habit and crystal form are critical elements in determining product properties and functions. In this work, we developed a microfluidic antisolvent crystallization technique to rapidly screen and accurately control the solid form and crystal habit of triphenylmethanol(Ph_(3)COH). This advanced technique separates the primary mixing of solutions from crystal formation(nucleation and growth) by introducing the microfluidic device, avoiding clogging in microchannels to obtain high-quality crystals. The results show that we can achieve controllable preparation of pure 2Ph_(3)COH·DMSO(DMSO solvate), pure Ph_(3)COH(form β), and mixed crystals with different mass ratios. Moreover, the microscale can prompt the DMSO solvate to grow into hexagonal sheet-like and bulk crystals. We can regulate the aspect ratio of hexagonal sheet-like crystals in binary solvents and control the crystal habit of the form β to transition between long needle-like shapes and short hexagonal prisms in DMF-H_(2)O. Meanwhile, we revealed that the solvent ratio, the antisolvent flow rate, and the initial concentration of Ph_(3)COH are the main factors affecting the solid form selectivity and morphology transition. Such a novel method would be considered as a promising technique to be extended to screen and control key crystallization parameters of other substances.展开更多
This study developed a numerical model to efficiently treat solid waste magnesium nitrate hydrate through multi-step chemical reactions.The model simulates two-phase flow,heat,and mass transfer processes in a pyrolysi...This study developed a numerical model to efficiently treat solid waste magnesium nitrate hydrate through multi-step chemical reactions.The model simulates two-phase flow,heat,and mass transfer processes in a pyrolysis furnace to improve the decomposition rate of magnesium nitrate.The performance of multi-nozzle and single-nozzle injection methods was evaluated,and the effects of primary and secondary nozzle flow ratios,velocity ratios,and secondary nozzle inclination angles on the decomposition rate were investigated.Results indicate that multi-nozzle injection has a higher conversion efficiency and decomposition rate than single-nozzle injection,with a 10.3%higher conversion rate under the design parameters.The decomposition rate is primarily dependent on the average residence time of particles,which can be increased by decreasing flow rate and velocity ratios and increasing the inclination angle of secondary nozzles.The optimal parameters are injection flow ratio of 40%,injection velocity ratio of 0.6,and secondary nozzle inclination of 30°,corresponding to a maximum decomposition rate of 99.33%.展开更多
Protonic solid oxide electrolysis cells(P-SOECs)are a promising technology for water electrolysis to produce green hydrogen.However,there are still challenges related key materials and anode/electrolyte interface.P-SO...Protonic solid oxide electrolysis cells(P-SOECs)are a promising technology for water electrolysis to produce green hydrogen.However,there are still challenges related key materials and anode/electrolyte interface.P-SOECs with Zr-rich electrolyte,called Zr-rich side P-SOECs,possess high thermodynamically stability under high steam concentrations but the large reaction resistances and the current leakage,thus the inferior performances.In this study,an efficient functional interlayer Ba_(0.95)La_(0.05)Fe_(0.8)Zn_(0.2)O_(3-δ)(BLFZ)in-between the anode and the electrolyte is developed.The electrochemical performances of P-SOECs are greatly enhanced because the BLFZ can greatly increase the interface contact,boost anode reaction kinetics,and increase proton injection into electrolyte.As a result,the P-SOEC yields high current density of 0.83 A cm^(-2) at 600℃ in 1.3 Vamong all the reported Zr-rich side cells.This work not only offers an efficient functional interlayer for P-SOECs but also holds the potential to achieve P-SOECs with high performances and long-term stability.展开更多
Solid oxide cells(SOCs)are emerging devices for efficient energy storage and conversion.However,during SOC operation,gaseous chromium(Cr)species released from Fe-Cr alloy interconnect can lead to Cr deposition and poi...Solid oxide cells(SOCs)are emerging devices for efficient energy storage and conversion.However,during SOC operation,gaseous chromium(Cr)species released from Fe-Cr alloy interconnect can lead to Cr deposition and poisoning of air electrodes,causing substantial degradation in electrochemical performance and compromising the longterm stability of SOCs.This mini-review examines the mechanism of Cr deposition and poisoning in air electrodes under both fuel-cell and electrolysis modes.Furthermore,emphasis is placed on the recent advancements in strategies to mitigate Cr poisoning,offering insights into the rational design and development of active and Cr-tolerant air electrodes for SOCs.展开更多
Reversible solid oxide cell(RSOC)is a new energy conversion device with significant applications,especially for power grid peaking shaving.However,the reversible conversion process of power generation/energy storage p...Reversible solid oxide cell(RSOC)is a new energy conversion device with significant applications,especially for power grid peaking shaving.However,the reversible conversion process of power generation/energy storage poses challenges for the performance and stability of air electrodes.In this work,a novel high-entropy perovskite oxide La_(0.2)Pr_(0.2)Gd_(0.2)Sm_(0.2)Sr_(0.2)Co_(0.8)Fe_(0.2)O_(3−δ)(HE-LSCF)is proposed and investigated as an air electrode in RSOC.The electrochemical behavior of HE-LSCF was studied as an air electrode in both fuel cell and electrolysis modes.The polarization impedance(Rp)of the HE-LSCF electrode is only 0.25Ω·cm^(2) at 800℃ in an air atmosphere.Notably,at an electrolytic voltage of 2 V and a temperature of 800℃,the current density reaches up to 1.68 A/cm^(2).The HE-LSCF air electrode exhibited excellent reversibility and stability,and its electrochemical performance remains stable after 100 h of reversible operation.With these advantages,HE-LSCF is shown to be an excellent air electrode for RSOC.展开更多
Coal-based soild wastes(CBSWs)are industrial byproducts that can be harmful to the environment.The exploitation and utilization of CBsWs offer societal advantages such as resource conservation,pollution reduction,and ...Coal-based soild wastes(CBSWs)are industrial byproducts that can be harmful to the environment.The exploitation and utilization of CBsWs offer societal advantages such as resource conservation,pollution reduction,and cost-effective production.However,environmentally sustainable management remains a worldwide challenge due to the substantial production volume and limited disposal capacity of CBSWs.The physicochemical properties and utilization of CBSWs are summarized,including fly ash,coal gangue and coal gasification slag.It also presents the current global applications status of CBSWs resources and examines market supply and demand.Subsequently,the paper provides an overview of studies on ways to utilise CBSWs,highlighting the primary avenues of CBSWs resource utilization which are mainly from the fields of chemical materials,metallurgy and agriculture.Furthermore,a comparative evaluation of the various methods for CBSWs resource recovery is conducted,outlining their respective advantages and disadvantages.The future development of CBSWs recycling processes is also discussed.The review concludes that while there is a growing need for attention in CBSWs recycling,its utilization will involve a combination of both large-scale treatment and refinement processes.The paper aims to offer references and insights for the effective utilization and environmental protection of CBSWs.Future direction will focus on the collaborative utilization of CBSWs,emphasizing on the combination of large-scale and high-value utilization.In addition,there is a need to establish a comprehensive database based on on-site production practices,explore on-site solutions to reduce transportation costs,and improve physicochemical properties during the production process.展开更多
As global energy demand increases and environmental standards tighten,the development of efficient,eco-friendly energy conversion and storage technologies becomes crucial.Solid oxide cells(SOCs)show great promise beca...As global energy demand increases and environmental standards tighten,the development of efficient,eco-friendly energy conversion and storage technologies becomes crucial.Solid oxide cells(SOCs)show great promise because of their high energy conversion efficiency and wide range of applications.Highentropy materials(HEMs),a novel class of materials comprising several principal elements,have attracted significant interest within the materials science and energy sectors.Their distinctive structural features and adaptable functional properties offer immense potential for innovation across various applications.This review systematically covers the basic concepts,crystal structures,element selection,and major synthesis strategies of HEMs,and explores in detail the specific applications of these materials in SOCs,including its potential as air electrodes,fuel electrodes,electrolytes,and interconnects(including barrier coatings).By analyzing existing studies,this review reveals the significant advantages of HEMs in enhancing the performance,anti-poisoning,and stability of SOCs;highlights the key areas and challenges for future research;and looks into possible future directions.展开更多
Minimizing the thermal expansion coefficient(TEC)mismatch between the cathode and electrolyte in solid oxide fuel cells is crucial for achieving stable,durable operation and high performance.Recently,materials with ne...Minimizing the thermal expansion coefficient(TEC)mismatch between the cathode and electrolyte in solid oxide fuel cells is crucial for achieving stable,durable operation and high performance.Recently,materials with negative thermal expansion(NTE)have at-tracted significant attention as effective additives for tailoring the thermomechanical properties of electrodes and enhancing cell durability.In this work,for the first time,single-phase NTE perovskite Sm_(0.85)Zn_(0.15)MnO_(3−δ)(SZM15)was successfully synthesized via the sol-gel method,eliminating the unwanted ZnO phase typically observed in materials obtained through the conventional solid-state reaction route.The sol-gel approach proved highly advantageous,offering low cost,robustness,excellent chemical homogeneity,precise compositional control,and high phase purity.After optimization of synthesis parameters,a negative TEC of approximately−6.5×10^(−6)K^(−1)was achieved in the 400-850℃range.SZM15 was then incorporated as an additive(10wt%-50wt%)into a SmBa0.5Sr0.5CoCuO_(5+δ)(SBSCCO)cathode to tune the thermomechanical properties with a La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(0.2)O_(3−δ)(LSGM)electrolyte,achieving a minimal TEC mismatch of only 1%.Notably,the SBSCCO+10wt%SZM15 composite cathode exhibited the lowest polarization resistance of 0.019Ω·cm^(2)at 900℃,showing approximately 70%lower than that of the pristine cathode.Excellent long-term stability after 100 h of operation was achieved.In addition,a high peak power density of 680 mW·cm^(−2)was achieved in a Ni-YSZ(yttria-stabilized zirconia)|YSZ|Ce_(0.9)Gd_(0.1)O_(2−δ)(GDC10)|SBSCCO+10wt%SZM15 anode-supported fuel cell at 850℃,highlighting the effectiveness of incorporating NTE materials as a promising strategy for regulating the thermomechanical properties and improving the long-term stability of intermediate temperature solid oxide fuel cells(IT-SOFCs).展开更多
Temperature is a critical factor influencing the performance of coal catalytic hydrogasification in bubbling fluidized bed gasifiers.Numerical simulations at various temperatures(1023 K,1073 K,1123 K,and 1173 K)are co...Temperature is a critical factor influencing the performance of coal catalytic hydrogasification in bubbling fluidized bed gasifiers.Numerical simulations at various temperatures(1023 K,1073 K,1123 K,and 1173 K)are conducted to elucidate the mechanisms by which temperature affects bubble size,global reaction performance,and particle-scale reactivity.The simulation results indicate that bubble size increases at elevated temperatures,while H_(2)-char hydrogasification reactivity is enhanced.Particle trajectory analyses reveal that particles sized between 100 and 250μm undergo intense char hydrogasification in the dense phase,contributing to the formation of hot spots.To assess the impact of temperature on the particle-scale flow-transfer-reaction process,the dimensionless quantities of Reynolds,Nusselt,and Sherwood numbers,along with the solids dispersion coefficient,are calculated.It is found that higher temperatures inhibit bubble-induced mass and heat transfer.In general,3 MPa,1123 K,and 3-4 fluidization numbers are identified as the optimal conditions for particles ranging from 0 to350μm.These findings provide valuable insights into the inherent interactions between temperature and gas-particle reaction.展开更多
Objective Burning solid cooking fuel contributes to household air pollution and is associated with frailty.However,how solid cooking fuel use contributes to the development of frailty has not been well illustrated.Met...Objective Burning solid cooking fuel contributes to household air pollution and is associated with frailty.However,how solid cooking fuel use contributes to the development of frailty has not been well illustrated.Methods This study recruited 8,947 participants aged≥45 years from the China Health and Retirement Longitudinal Study,2011–2018.Group-based trajectory modeling was employed to identify frailty trajectories.Multinomial logistic regression was used to assess the association between solid cooking fuel use and frailty trajectories.Population-attributable fractions were used to estimate the frailty burden from solid fuel use.Results We identified three frailty trajectories:low-stable(n=5,789),moderate-increasing(n=2,603),and fast-increasing(n=555).Solid fuel use was associated with higher odds of being in the moderate-increasing(OR:1.24,95%CI:1.08–1.42)and fast-increasing(OR:1.48,95%CI:1.14–1.92)trajectories.These associations were strengthened by longer solid fuel use(P for trend<0.001).Switching to clean fuel significantly reduced the risk of being in these trajectories compared with persistent solid fuel users.Without solid fuel,8%of moderate-and 19%of fast-increasing trajectories demonstrated frailty development like the low-stable group.Conclusion Solid cooking fuel use is associated with frailty trajectories in middle-aged and older Chinese populations.展开更多
BACKGROUND Anxiety and depression are prevalent among patients with chronic heart failure(CHF)and can adversely contribute to treatment adherence and clinical outcomes.Poor fluid restriction adherence is a widespread ...BACKGROUND Anxiety and depression are prevalent among patients with chronic heart failure(CHF)and can adversely contribute to treatment adherence and clinical outcomes.Poor fluid restriction adherence is a widespread challenge in the management of CHF.To effectively manage disease progression and alleviate symptoms,it is crucial to identify key influencing factors to facilitate the implementation of targeted interventions.AIM To investigate the status of anxiety and depression among patients with CHF and determine the factors contributing to poor fluid restriction adherence.METHODS Three hundred CHF patients seeking medical treatment at The First Hospital of Hunan University of Traditional Chinese Medicine between June 2021 and June 2023 were included in the study.Questionnaires,including the Psychosomatic Symptom Scale,Self-Rating Anxiety Scale,Self-Rating Depression Scale,and Fluid Restriction Adherence Questionnaire were administered to patients.Based on their anxiety and depression scores,patients were categorized into anxiety/depression and non-anxiety/depression groups,as well as fluid restriction adherence and fluid restriction non-adherence groups.General patient data were collected,and univariate and logistic regression analyses were conducted to determine the occurrence of depression and anxiety.Logistic regression analysis was used to identify independent factors influencing fluid restriction adherence.RESULTS Statistically significant differences in age,New York Heart Association(NYHA)grading,marital status,educational attainment,and family support were observed between depressed and non-depressed CHF patients(P<0.05).Age,NYHA grading,marital status,educational attainment,and family support were identified as factors influencing the development of depression.The anxiety and non-anxiety groups differed statistically in terms of gender,age,NYHA grading,smoking history,alcohol consumption history,monthly income,educational attainment,and family support(P<0.05).Gender,smoking,alcohol consumption,monthly income,and educational attainment affected anxiety in these patients.The fluid restriction adherence rate was 28.0%,and thirst sensation,anxiety,and depression were identified as independent influencing factors.CONCLUSION CHF patients are susceptible to anxiety and depression,with multiple associated influencing factors.Moreover,anxiety and depression are independent factors that can influence fluid restriction adherence in these patients.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.51172192,11272275 and 11002122)the Natural Science Foundation of Hunan Province(Grant No.11JJ4003)the Doctoral Scientific Research Foundation of Xiangtan University(Grant Nos.KZ08022,KZ03013 and KF20140303)
文摘To study the temperature distribution and thermal-stress field in different service stages, a two-dimensional model of a turbine blade with thermal barrier coatings is developed, in which the conjugate heat transfer analysis and the decoupled thermal-stress calculation method are adopted. Based on the simulation results, it is found that a non-uniform distribution of temperature appears in different positions of the blade surface, which has directly impacted on stress field. The maximum temperature with a value of 1030 ℃ occurs at the leading edge. During the steady stage, the maximum stress of thermally grown oxide （TGO） appears in the middle of the suction side, reaching 3.75 GPa. At the end stage of cooling, the maximum compressive stress of TGO with a value of-3.5 GPa occurs at the leading edge. Thus, it can be predicted that during the steady stage the dangerous regions may locate at the suction side, while the leadine edge mav be more Drone to failure on cooling.
基金the financial supports provided by the Natural Science Fund of Jiangsu Province,China(No.BK20200448)the Postdoctoral Science Foundation of China(No.2020TQ0143)。
文摘Gas foil bearing faces severe and complex thermal-fluid–solid coupling issues when in ultra-high speed and miniaturized impeller machineries.In this study,a Thermo-Elasto-Hydrodynamic(TEHD)analysis of a specific multi-layer gas foil thrust bearing on the continuous loading process within a steady rotational speed is numerically investigated by a three-dimensional thermal-fluid–solid coupling method.Results indicate that the multi-layer foil exhibits nonlinear overall stiffness,with the thrust bottom foil serving as the primary elastic deformation structure,while the thrust top foil maintains a well-defined aerodynamic shape during a loading process,which helps reduce frictional damage and achieve an adequate loading capacity.For low loads,the fluctuation of the gas film is extremely sensitive,and it weakens dramatically as the load increases.The viscous heating and friction torque exhibit a linear relationship with an increasing bearing load after a rapid growth.Depending on the exact stacking sequence and contact position of the multi-layer gas foil,the overlapping configuration allows for efficient transfer of viscous-shearing heat accumulated at the smallest air film through thermal conduction while providing elastic support.Due to the strong inhomogeneity of the viscous heat under varying loads,the temperature distribution on the top foil surface shows pronounced variations,while the difference between the peak and average temperatures of the thrust plate and top foil surfaces widens substantially with an increasing load.
基金financially supported by the Natural Science Foundation of China(No.41774133)the Open Funds of SINOPEC Key Laboratory of Geophysics(No.wtyjy-wx2017-01-04)National Science and Technology Major Project of the Ministry of Science and Technology of China(No.2016ZX05024-003-011)
文摘In marine seismic exploration, ocean-bottom cable techniques accurately record the multicomponent seismic wavefield; however, the seismic wave propagation in fluid–solid media cannot be simulated by a single wave equation. In addition, when the seabed interface is irregular, traditional finite-difference schemes cannot simulate the seismic wave propagation across the irregular seabed interface. Therefore, an acoustic–elastic forward modeling and vector-based P-and S-wave separation method is proposed. In this method, we divide the fluid–solid elastic media with irregular interface into orthogonal grids and map the irregular interface in the Cartesian coordinates system into a horizontal interface in the curvilinear coordinates system of the computational domain using coordinates transformation. The acoustic and elastic wave equations in the curvilinear coordinates system are applied to the fluid and solid medium, respectively. At the irregular interface, the two equations are combined into an acoustic–elastic equation in the curvilinear coordinates system. We next introduce a full staggered-grid scheme to improve the stability of the numerical simulation. Thus, separate P-and S-wave equations in the curvilinear coordinates system are derived to realize the P-and S-wave separation method.
基金supported by the Innovative Research Group Project of the National Natural Science Foundation of China(22021004)Sinopec Major Science and Technology Projects(321123-1)。
文摘Coking at the fractionating tower bottom and the decant oil circulation system disrupts the heat balance,leading to unplanned shutdown and destroying the long period stable operation of the Fluid Catalytic Cracking Unit(FCCU).The FCCU operates through interconnected subsystems,generating high-dimensional,nonlinear,and non-stationary data characterized by spatiotemporally correlated.The decant oil solid content is the crucial indicator for monitoring catalyst loss from the reactor-regenerator system and coking risk tendency at the fractionating tower bottom that relies on sampling and laboratory testing,which is lagging responsiveness and labor-intensive.Developing the online decant oil solid content soft sensor using industrial data to support operators in conducting predictive maintenance is essential.Therefore,this paper proposes a hybrid deep learning framework for soft sensor development that combines spatiotemporal pattern extraction with interpretability,enabling accurate risk identification in dynamic operational conditions.This framework employs a Filter-Wrapper method for dimensionality reduction,followed by a 2D Convolutional Neural Network(2DCNN)for extracting spatial patterns,and a Bidirectional Gated Recurrent Unit(BiGRU)for capturing long-term temporal dependencies,with an Attention Mechanism(AM)to highlight critical features adaptively.The integration of SHapley Additive exPlanations(SHAP),Complementary Ensemble Empirical Mode Decomposition with Adaptive Noise(CEEMDAN),2DCNN,and expert knowledge precisely quantifies feature contributions and decomposes signals,significantly enhancing the practicality of risk identification.Applied to a China refinery with processing capacity of 2.80×10^(6) t/a,the soft sensor achieved the R^(2) value of 0.93 and five-level risk identification accuracy of 96.42%.These results demonstrate the framework's accuracy,robustness,and suitability for complex industrial scenarios,advancing risk visualization and management.
基金supported by the National Natural Science Foundation for International Young Scientists of China(Grant No.52150410427)funding of Scientific Research Startup Project for High-Level Talents of Shandong Institute of Petroleum and Chemical Technology(Grant No.DJB2023020 and Grant No.2023SS019).
文摘Smart low-solid drilling fluids(SLSDFs)with thermo-controllable rheological properties and attractive thickening characteristics have recently captivated profound attention due to their low formation damage and enhanced cuttings lifting capacity.However,their applications to deep hole drilling at high temperatures have remained limited because of the thermal instability and environmental constraints of the thermo-associating polymers as additives.This work explored the synergistic benefits of thermo-associating polymer and biogenic nano-silica(B-SiNP)extracted from rice husk to improve the thermo-stability of SLSDF.This study shows that the nano-hybrid,TAP-S based on vinyl-terminated B-SiNP could potentially mitigate the limiting performance of conventional LSDF(F-2)caused by the failure of thermo-associating copolymers under elevated temperatures.TAP-S bearing drilling fluid(F-3)could preserve more than 5.6-fold of its initial properties(ca.apparent viscosity,plastic viscosity,yield point,and gel strength)with a nearly flat-gel profile in the temperature range of 25-230℃,which was higher than those of the counterpart F-2 and base fluid according to the results of rheological tests analysis.In addition,TAP-S exhibited an abrupt thermo-thickening characteristic with a magnitude declining by only 1.05-fold and the activation Gibbs free energy of 1339 kJ/mol above the plateau(ca.130℃),reflecting its less sensitivity compared to F-2 under a continuous heating process.As a result,a lower temperature was required to drive the dehydration of the residual fraction of lower critical solution temperature(LCST)in nano-hybrid structures than TAP according to the results of DSC analysis.Thus,lower energy was expected to disintegrate the residual hydrogen bonds formed between the LCST chains and surrounding water molecules at elevated temperatures.Moreover,TAP-S formed a solid-micro-crosslinking structure network which exhibited a more stable hydrodynamic diameter as revealed by DLS analysis.Compared with TAP,TAP-S consisted of a larger composite B-SiNP-TAP integrated spatial network structure based on the results of environmental scanning electron microscope,which conferred a degree of thermal conductivity characteristic for improved temperature resistance.This contributed to the effective binding onto bentonite particles for protection and maintained a relatively stable bentonite particle dispersion according to the results of EPM and particle size distribution analyses.Consequently,TAP-S fortified drilling fluid demonstrates improved rheological and filtration performance under severe downhole conditions.Therefore,TAP-S,the thermo-associating copolymer integrated with B-SiNP could find potential application as an eco-friendly viscosifier in LSDFs for deep-well drilling operations.
基金supported by National Natural Science Foundation of China(Grant No.52270106 and 22266021)Yunnan Major Scientific and Technological Projects(grant No.202202AG050005)Yunnan Fundamental Research Projects(grant No.202201AT070116).
文摘The application of industrial solid wastes as environmentally functional materials for air pollutants control has gained much attention in recent years due to its potential to reduce air pollution in a cost-effective manner.In this review,we investigate the development of industrialwaste-based functional materials for various gas pollutant removal and consider the relevant reaction mechanism according to different types of industrial solid waste.We see a recent effort towards achieving high-performance environmental functional materials via chemical or physical modification,in which the active components,pore size,and phase structure can be altered.The review will discuss the potential of using industrial solid wastes,these modified materials,or synthesized materials from raw waste precursors for the removal of air pollutants,including SO_(2),NO_(x),Hg^(0),H_(2)S,VOCs,and CO_(2).The challenges still need to be addressed to realize this potential and the prospects for future research fully.The suggestions for future directions include determining the optimal composition of these materials,calculating the real reaction rate and turnover frequency,developing effective treatment methods,and establishing chemical component databases of raw industrial solid waste for catalysts/adsorbent preparation.
基金supported by the National Natural Science Foundation of China (No.22278128)。
文摘Crystal habit and crystal form are critical elements in determining product properties and functions. In this work, we developed a microfluidic antisolvent crystallization technique to rapidly screen and accurately control the solid form and crystal habit of triphenylmethanol(Ph_(3)COH). This advanced technique separates the primary mixing of solutions from crystal formation(nucleation and growth) by introducing the microfluidic device, avoiding clogging in microchannels to obtain high-quality crystals. The results show that we can achieve controllable preparation of pure 2Ph_(3)COH·DMSO(DMSO solvate), pure Ph_(3)COH(form β), and mixed crystals with different mass ratios. Moreover, the microscale can prompt the DMSO solvate to grow into hexagonal sheet-like and bulk crystals. We can regulate the aspect ratio of hexagonal sheet-like crystals in binary solvents and control the crystal habit of the form β to transition between long needle-like shapes and short hexagonal prisms in DMF-H_(2)O. Meanwhile, we revealed that the solvent ratio, the antisolvent flow rate, and the initial concentration of Ph_(3)COH are the main factors affecting the solid form selectivity and morphology transition. Such a novel method would be considered as a promising technique to be extended to screen and control key crystallization parameters of other substances.
基金the financial support for this work provided by the National Key R&D Program of China‘Technologies and Integrated Application of Magnesite Waste Utilization for High-Valued Chemicals and Materials’(2020YFC1909303)。
文摘This study developed a numerical model to efficiently treat solid waste magnesium nitrate hydrate through multi-step chemical reactions.The model simulates two-phase flow,heat,and mass transfer processes in a pyrolysis furnace to improve the decomposition rate of magnesium nitrate.The performance of multi-nozzle and single-nozzle injection methods was evaluated,and the effects of primary and secondary nozzle flow ratios,velocity ratios,and secondary nozzle inclination angles on the decomposition rate were investigated.Results indicate that multi-nozzle injection has a higher conversion efficiency and decomposition rate than single-nozzle injection,with a 10.3%higher conversion rate under the design parameters.The decomposition rate is primarily dependent on the average residence time of particles,which can be increased by decreasing flow rate and velocity ratios and increasing the inclination angle of secondary nozzles.The optimal parameters are injection flow ratio of 40%,injection velocity ratio of 0.6,and secondary nozzle inclination of 30°,corresponding to a maximum decomposition rate of 99.33%.
基金financial support from the JSPS KAKENHI Grant-in-Aid for Scientific Research(B),No.21H02035KAKENHI Grant-in-Aid for Challenging Research(Exploratory),No.21K19017+2 种基金KAKENHI Grant-in-Aid for Transformative Research Areas(B),No.21H05100National Natural Science Foundation of China,No.22409033 and No.22409035Basic and Applied Basic Research Foundation of Guangdong Province,No.2022A1515110470.
文摘Protonic solid oxide electrolysis cells(P-SOECs)are a promising technology for water electrolysis to produce green hydrogen.However,there are still challenges related key materials and anode/electrolyte interface.P-SOECs with Zr-rich electrolyte,called Zr-rich side P-SOECs,possess high thermodynamically stability under high steam concentrations but the large reaction resistances and the current leakage,thus the inferior performances.In this study,an efficient functional interlayer Ba_(0.95)La_(0.05)Fe_(0.8)Zn_(0.2)O_(3-δ)(BLFZ)in-between the anode and the electrolyte is developed.The electrochemical performances of P-SOECs are greatly enhanced because the BLFZ can greatly increase the interface contact,boost anode reaction kinetics,and increase proton injection into electrolyte.As a result,the P-SOEC yields high current density of 0.83 A cm^(-2) at 600℃ in 1.3 Vamong all the reported Zr-rich side cells.This work not only offers an efficient functional interlayer for P-SOECs but also holds the potential to achieve P-SOECs with high performances and long-term stability.
基金supported by National Natural Science Foundation of China(22279018)National Natural Science Foundation of China(22005055)Natural Science Foundation of Fujian Province(2022J01085).
文摘Solid oxide cells(SOCs)are emerging devices for efficient energy storage and conversion.However,during SOC operation,gaseous chromium(Cr)species released from Fe-Cr alloy interconnect can lead to Cr deposition and poisoning of air electrodes,causing substantial degradation in electrochemical performance and compromising the longterm stability of SOCs.This mini-review examines the mechanism of Cr deposition and poisoning in air electrodes under both fuel-cell and electrolysis modes.Furthermore,emphasis is placed on the recent advancements in strategies to mitigate Cr poisoning,offering insights into the rational design and development of active and Cr-tolerant air electrodes for SOCs.
基金supported by Fundamental Research Funds for the Central Universities(2023KYJD1008)the Science Research Projects of the Anhui Higher Education Institutions of China(2022AH051582).
文摘Reversible solid oxide cell(RSOC)is a new energy conversion device with significant applications,especially for power grid peaking shaving.However,the reversible conversion process of power generation/energy storage poses challenges for the performance and stability of air electrodes.In this work,a novel high-entropy perovskite oxide La_(0.2)Pr_(0.2)Gd_(0.2)Sm_(0.2)Sr_(0.2)Co_(0.8)Fe_(0.2)O_(3−δ)(HE-LSCF)is proposed and investigated as an air electrode in RSOC.The electrochemical behavior of HE-LSCF was studied as an air electrode in both fuel cell and electrolysis modes.The polarization impedance(Rp)of the HE-LSCF electrode is only 0.25Ω·cm^(2) at 800℃ in an air atmosphere.Notably,at an electrolytic voltage of 2 V and a temperature of 800℃,the current density reaches up to 1.68 A/cm^(2).The HE-LSCF air electrode exhibited excellent reversibility and stability,and its electrochemical performance remains stable after 100 h of reversible operation.With these advantages,HE-LSCF is shown to be an excellent air electrode for RSOC.
基金supported by the following:“National Natural Science Foundation of China”(22478231)“Natural Science Foundation of Henan”(242300421449)“Fundamental Research Program of Shanxi Province”(202403021221011).
文摘Coal-based soild wastes(CBSWs)are industrial byproducts that can be harmful to the environment.The exploitation and utilization of CBsWs offer societal advantages such as resource conservation,pollution reduction,and cost-effective production.However,environmentally sustainable management remains a worldwide challenge due to the substantial production volume and limited disposal capacity of CBSWs.The physicochemical properties and utilization of CBSWs are summarized,including fly ash,coal gangue and coal gasification slag.It also presents the current global applications status of CBSWs resources and examines market supply and demand.Subsequently,the paper provides an overview of studies on ways to utilise CBSWs,highlighting the primary avenues of CBSWs resource utilization which are mainly from the fields of chemical materials,metallurgy and agriculture.Furthermore,a comparative evaluation of the various methods for CBSWs resource recovery is conducted,outlining their respective advantages and disadvantages.The future development of CBSWs recycling processes is also discussed.The review concludes that while there is a growing need for attention in CBSWs recycling,its utilization will involve a combination of both large-scale treatment and refinement processes.The paper aims to offer references and insights for the effective utilization and environmental protection of CBSWs.Future direction will focus on the collaborative utilization of CBSWs,emphasizing on the combination of large-scale and high-value utilization.In addition,there is a need to establish a comprehensive database based on on-site production practices,explore on-site solutions to reduce transportation costs,and improve physicochemical properties during the production process.
基金supported by the National Key R&D Program of China(2022YFB4004000)National Natural Science Foundation of China(U24A20542,52472210,22279057)+3 种基金Natural Science Foundation of Jiangsu Province(BK20221312)Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX23_1465)Cultivation Program for the Excellent Doctoral Dissertation of Nanjing Tech University(2023-09)the grant of Hydrogen Energy Laboratory(No.FEUZ-2024-0009)。
文摘As global energy demand increases and environmental standards tighten,the development of efficient,eco-friendly energy conversion and storage technologies becomes crucial.Solid oxide cells(SOCs)show great promise because of their high energy conversion efficiency and wide range of applications.Highentropy materials(HEMs),a novel class of materials comprising several principal elements,have attracted significant interest within the materials science and energy sectors.Their distinctive structural features and adaptable functional properties offer immense potential for innovation across various applications.This review systematically covers the basic concepts,crystal structures,element selection,and major synthesis strategies of HEMs,and explores in detail the specific applications of these materials in SOCs,including its potential as air electrodes,fuel electrodes,electrolytes,and interconnects(including barrier coatings).By analyzing existing studies,this review reveals the significant advantages of HEMs in enhancing the performance,anti-poisoning,and stability of SOCs;highlights the key areas and challenges for future research;and looks into possible future directions.
基金supported by the research project within the program“Excellence Initiative-Research University”for the AGH University of Krakow(IDUB AGH,Action 21)Kun Zheng acknowledges financial support from AGH University of Krakow(No.16.16.210.476).
文摘Minimizing the thermal expansion coefficient(TEC)mismatch between the cathode and electrolyte in solid oxide fuel cells is crucial for achieving stable,durable operation and high performance.Recently,materials with negative thermal expansion(NTE)have at-tracted significant attention as effective additives for tailoring the thermomechanical properties of electrodes and enhancing cell durability.In this work,for the first time,single-phase NTE perovskite Sm_(0.85)Zn_(0.15)MnO_(3−δ)(SZM15)was successfully synthesized via the sol-gel method,eliminating the unwanted ZnO phase typically observed in materials obtained through the conventional solid-state reaction route.The sol-gel approach proved highly advantageous,offering low cost,robustness,excellent chemical homogeneity,precise compositional control,and high phase purity.After optimization of synthesis parameters,a negative TEC of approximately−6.5×10^(−6)K^(−1)was achieved in the 400-850℃range.SZM15 was then incorporated as an additive(10wt%-50wt%)into a SmBa0.5Sr0.5CoCuO_(5+δ)(SBSCCO)cathode to tune the thermomechanical properties with a La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(0.2)O_(3−δ)(LSGM)electrolyte,achieving a minimal TEC mismatch of only 1%.Notably,the SBSCCO+10wt%SZM15 composite cathode exhibited the lowest polarization resistance of 0.019Ω·cm^(2)at 900℃,showing approximately 70%lower than that of the pristine cathode.Excellent long-term stability after 100 h of operation was achieved.In addition,a high peak power density of 680 mW·cm^(−2)was achieved in a Ni-YSZ(yttria-stabilized zirconia)|YSZ|Ce_(0.9)Gd_(0.1)O_(2−δ)(GDC10)|SBSCCO+10wt%SZM15 anode-supported fuel cell at 850℃,highlighting the effectiveness of incorporating NTE materials as a promising strategy for regulating the thermomechanical properties and improving the long-term stability of intermediate temperature solid oxide fuel cells(IT-SOFCs).
基金supported by the National Natural Science Foundation of China(22308170).
文摘Temperature is a critical factor influencing the performance of coal catalytic hydrogasification in bubbling fluidized bed gasifiers.Numerical simulations at various temperatures(1023 K,1073 K,1123 K,and 1173 K)are conducted to elucidate the mechanisms by which temperature affects bubble size,global reaction performance,and particle-scale reactivity.The simulation results indicate that bubble size increases at elevated temperatures,while H_(2)-char hydrogasification reactivity is enhanced.Particle trajectory analyses reveal that particles sized between 100 and 250μm undergo intense char hydrogasification in the dense phase,contributing to the formation of hot spots.To assess the impact of temperature on the particle-scale flow-transfer-reaction process,the dimensionless quantities of Reynolds,Nusselt,and Sherwood numbers,along with the solids dispersion coefficient,are calculated.It is found that higher temperatures inhibit bubble-induced mass and heat transfer.In general,3 MPa,1123 K,and 3-4 fluidization numbers are identified as the optimal conditions for particles ranging from 0 to350μm.These findings provide valuable insights into the inherent interactions between temperature and gas-particle reaction.
基金supported by the National Natural Science Foundation of China(82222064,81973147)the National Key Research and Development Program(2022YFC2010100)the Shandong University Distinguished Young Scholars。
文摘Objective Burning solid cooking fuel contributes to household air pollution and is associated with frailty.However,how solid cooking fuel use contributes to the development of frailty has not been well illustrated.Methods This study recruited 8,947 participants aged≥45 years from the China Health and Retirement Longitudinal Study,2011–2018.Group-based trajectory modeling was employed to identify frailty trajectories.Multinomial logistic regression was used to assess the association between solid cooking fuel use and frailty trajectories.Population-attributable fractions were used to estimate the frailty burden from solid fuel use.Results We identified three frailty trajectories:low-stable(n=5,789),moderate-increasing(n=2,603),and fast-increasing(n=555).Solid fuel use was associated with higher odds of being in the moderate-increasing(OR:1.24,95%CI:1.08–1.42)and fast-increasing(OR:1.48,95%CI:1.14–1.92)trajectories.These associations were strengthened by longer solid fuel use(P for trend<0.001).Switching to clean fuel significantly reduced the risk of being in these trajectories compared with persistent solid fuel users.Without solid fuel,8%of moderate-and 19%of fast-increasing trajectories demonstrated frailty development like the low-stable group.Conclusion Solid cooking fuel use is associated with frailty trajectories in middle-aged and older Chinese populations.
基金Huxiang TCM Physique Intervention Clinical Research Center,No.2023SK4061Traditional Chinese Medicine Research Project of Hunan Province,No.B2023065+4 种基金Hunan Province"14th Five-Year Plan"key specialty of TCM,No.[2023]4Hunan University of Chinese Medicine and Hospital Joint Foundation,No.2023XYLH019 and 2024XYLH365R&D Plan for Key Areas of Hunan Provincial Department of Science and Technology,No.2019SK2321Excellent Youth Program of Hunan Education Department,No.24B0346Hunan Provincial Natural Science Foundation for Young Scientists,No.2025JJ60626.
文摘BACKGROUND Anxiety and depression are prevalent among patients with chronic heart failure(CHF)and can adversely contribute to treatment adherence and clinical outcomes.Poor fluid restriction adherence is a widespread challenge in the management of CHF.To effectively manage disease progression and alleviate symptoms,it is crucial to identify key influencing factors to facilitate the implementation of targeted interventions.AIM To investigate the status of anxiety and depression among patients with CHF and determine the factors contributing to poor fluid restriction adherence.METHODS Three hundred CHF patients seeking medical treatment at The First Hospital of Hunan University of Traditional Chinese Medicine between June 2021 and June 2023 were included in the study.Questionnaires,including the Psychosomatic Symptom Scale,Self-Rating Anxiety Scale,Self-Rating Depression Scale,and Fluid Restriction Adherence Questionnaire were administered to patients.Based on their anxiety and depression scores,patients were categorized into anxiety/depression and non-anxiety/depression groups,as well as fluid restriction adherence and fluid restriction non-adherence groups.General patient data were collected,and univariate and logistic regression analyses were conducted to determine the occurrence of depression and anxiety.Logistic regression analysis was used to identify independent factors influencing fluid restriction adherence.RESULTS Statistically significant differences in age,New York Heart Association(NYHA)grading,marital status,educational attainment,and family support were observed between depressed and non-depressed CHF patients(P<0.05).Age,NYHA grading,marital status,educational attainment,and family support were identified as factors influencing the development of depression.The anxiety and non-anxiety groups differed statistically in terms of gender,age,NYHA grading,smoking history,alcohol consumption history,monthly income,educational attainment,and family support(P<0.05).Gender,smoking,alcohol consumption,monthly income,and educational attainment affected anxiety in these patients.The fluid restriction adherence rate was 28.0%,and thirst sensation,anxiety,and depression were identified as independent influencing factors.CONCLUSION CHF patients are susceptible to anxiety and depression,with multiple associated influencing factors.Moreover,anxiety and depression are independent factors that can influence fluid restriction adherence in these patients.
