The effects of basicities and equilibrium temperatures on the enrichment of chromium in different mineral phases of synthesized argon-oxygen decarburization slags were investigated to understand the Cr concentrating b...The effects of basicities and equilibrium temperatures on the enrichment of chromium in different mineral phases of synthesized argon-oxygen decarburization slags were investigated to understand the Cr concentrating behavior into Mg(Cr,Al)2O4 spinel phase and to determine the leaching stability of Cr-containing slag.The results showed that when the basicity decreased from 1.0 to 0.6 and temperatures decreased from 1600 to 800℃,the Cr content of amorphous phase and crystalline phase gradually decreased,with a subsequent increase in the Cr content of spinel phase.The range of Cr enrichment in spinel of slags S1,S2,and S3 is 92.03-96.89,91.63-96.36,and 90.67-95.42,respectively.The mass fraction and the size of spinel increased with the decreasing equilibrium temperatures,and the Cr leaching values decreased simultaneously.Therefore,the trend of the amount of Cr-related ions in the leachate was consistent with the trend of Cr in the amorphous phase,diopside,and akermanite.The results suggest that the lower basicity and equilibrium temperatures could be conducive to stabilizing Cr into spinel phase to minimize Cr leaching into the environment.展开更多
Alumina magnesia castable crucible specimens were prepared using tabular corundum （ ≤ 5 mm ）, fused magnesia powder （ ≤0. 088 mm ） , fused spinel powder （ ≤0. 044 mm ） , and α-Al2O3. micropowder （d50 ≤0....Alumina magnesia castable crucible specimens were prepared using tabular corundum （ ≤ 5 mm ）, fused magnesia powder （ ≤0. 088 mm ） , fused spinel powder （ ≤0. 044 mm ） , and α-Al2O3. micropowder （d50 ≤0. 7 μm ） as main starting materials, batching, mixing, shaping, and drying. Slag resistance was determined by static crucible method at 1 600℃ for 3 h adopting two ladle slags with different basicities （3. 40 and 1.03 ）. The corrosion and penetration indexes and microstructure characteristics of the specimens after slag resistance test were analyzed to study the corrosion behaviors of the two slags to alumina magnesia castables. The results show that the corrosion of the low basicity slag to alumina magnesia custables is much more serious than that of the high basicity slag for that their reactions with castables form different products;for the low basicity slab,, the multi-phase coexistence of CA6 and compounds of CaO - Al2O3 -SiO2 in the materials together with volume expansion caused by the formation of CA6 intensify the slag corrosion and penetration ; for the high basicity slag, the reaction between slag and castables generates a CA2 dense layer and a large amount of in-situ MA in the interface, reducing the slag corrosion to the materials effectively.展开更多
Vaccination is a key strategy to curb the spread of epidemics.Heterologous vaccination,unlike homologous vaccination which acts on a single target and forms a single immune barrier,covers multiple targets for broader ...Vaccination is a key strategy to curb the spread of epidemics.Heterologous vaccination,unlike homologous vaccination which acts on a single target and forms a single immune barrier,covers multiple targets for broader protection.Yet,heterologous vaccination involves a complex decision process that conventional game-theoretic approaches,such as classical,evolutionary,and minority games cannot adequately capture.The parallel minority game(PMG)can handle bounded-rational,multi-choice decisions,but its application in vaccine research remains rare.In this study,we propose a vaccination-transmission coupled dynamic mechanism based on the parallel minority game and simulate it on a two-dimensional lattice.Using actual observational data and a mean-field mathematical model,we verify the effectiveness of this mechanism in simulating realistic vaccination behavior and transmission dynamics.We further analyze the impact of key parameters,such as vaccine efficacy differences and the proportion of individuals eligible for vaccine switching,on containment effectiveness.Our results demonstrate that heterologous vaccination surpasses homologous vaccination in containment effectiveness,particularly when vaccine efficacy varies significantly.This work provides a novel framework and empirical evidence for understanding individual decision-making and population-wide immunity formation in multi-vaccine settings.展开更多
Agricultural development is regarded as the most important foundation of China’s modernisation.According to the Recommendations of the CPC Central Committee for Formulating the 15th Five-Year Plan for National Econom...Agricultural development is regarded as the most important foundation of China’s modernisation.According to the Recommendations of the CPC Central Committee for Formulating the 15th Five-Year Plan for National Economic and Social Development(2026–2030),issues related to agriculture,rural areas and rural residents should be given top priority.In the coming years,China will promote coordinated urban and rural development,continue to consolidate and expand the achievements of poverty alleviation,ensure basic modern living conditions in rural areas,and accelerate progress in building a strong agricultural sector.展开更多
AAV-PHP.eB is an artificial adeno-associated virus(AAV)that crosses the blood-brain barrier and targets neurons more efficiently than other AAVs when administered systematically.While AAV-PHP.eB has been used in vario...AAV-PHP.eB is an artificial adeno-associated virus(AAV)that crosses the blood-brain barrier and targets neurons more efficiently than other AAVs when administered systematically.While AAV-PHP.eB has been used in various disease models,its cellular tropism in cerebrovascular diseases remains unclear.In the present study,we aimed to elucidate the tropism of AAV-PHP.eB for different cell types in the brain in a mouse model of ischemic stroke and evaluate its effectiveness in mediating basic fibroblast growth factor(bFGF)gene therapy.Mice were injected intravenously with AAV-PHP.eB either 14 days prior to(pre-stroke)or 1 day following(post-stroke)transient middle cerebral artery occlusion.Notably,we observed a shift in tropism from neurons to endothelial cells with post-stroke administration of AAV-PHP.eB-mNeonGreen(mNG).This endothelial cell tropism correlated strongly with expression of the endothelial membrane receptor lymphocyte antigen 6 family member A(Ly6A).Furthermore,AAV-PHP.eB-mediated overexpression of bFGF markedly improved neurobehavioral outcomes and promoted long-term neurogenesis and angiogenesis post-ischemic stroke.Our findings underscore the significance of considering potential tropism shifts when utilizing AAV-PHP.eB-mediated gene therapy in neurological diseases and suggest a promising new strategy for bFGF gene therapy in stroke treatment.展开更多
Objectives:The current treatment options and therapeutic targets for triple-negative breast cancer(TNBC),an aggressive subtype of breast cancer(BrCA),are limited.This study aimed to identify novel biomarkers and trans...Objectives:The current treatment options and therapeutic targets for triple-negative breast cancer(TNBC),an aggressive subtype of breast cancer(BrCA),are limited.This study aimed to identify novel biomarkers and transcriptional regulatory networks(TRN)inherent in TNBC samples.Methods:We analyzed pan-cancer BrCA datasets from The Cancer Genome Atlas(TCGA)to compare triple-positive breast cancer(TPBC)with TNBC.TRN algorithms and virtual inference of protein-enriched regulon(VIPER)were used to identify master regulators and their target genes.Utilizing TNBC cells(MDA-MB-231 and MDA-MB-468),we validated the relationship of nuclear factor erythroid 2-like 3(NFE2L3)and basic helix-loop-helix family member E 40(BHLHE40)by performing a luciferase assay.The expression levels of these targets were measured after transfections with plasmid and siRNA via qRT-PCR and western blots.The effect of these genes on cell proliferation and migration was studied using phenotypic assays.Results:Using computational approaches,we identified NFE2L3 as a master regulator with BHLHE40 as its target gene.NFE2L3 protein binds to the promoter region of BHLHE40 and regulates its transcriptional activity.Additionally,silencing and overexpressing NFE2L3 and BHLHE40 in TNBC cell lines MDA-MB-231 and MDA-MB-468 showed that NFE2L3 directly regulates BHLHE40 at both transcriptional and translational levels.We found that BHLHE40 requires NFE2L3 for cell proliferation and migration in TNBC.Conclusion:These findings underscore the significance of NFE2L3 and BHLHE40 in TNBC,highlighting NFE2L3’s role in regulating the oncogenic activity of BHLHE40 in TNBC cells.展开更多
The selection of an appropriate basic detonation wave flow field is crucial for improving the performance and geometric design of standing detonation vehicles.This paper employs a detailed chemical reaction model and ...The selection of an appropriate basic detonation wave flow field is crucial for improving the performance and geometric design of standing detonation vehicles.This paper employs a detailed chemical reaction model and solves the unsteady axisymmetric Euler equation to study the characteristics of the Axisymmetric Inward Turning Curved Detonation Wave(AIT-CDW)flow field and the parameters affecting the stability of the wave system structure of AIT-CDW flow field.The numerical results demonstrate a radial compression effect in the AIT-CDW flow field.This effect causes the detonation wave to have a shorter initiation length than oblique detonation wave flow field and the detonation wave angle to gradually increase with the flow direction postdetonation.The AIT-CDW flow field is confined space,making it prone to normal detonation waves when the detonation wave reflects from the wall.This phenomenon is detrimental to the stability of the wave system structure in the flow field.It has been observed that increasing the center body radius and decreasing the fuel equivalent ratio can effectively reduce the height of the normal detonation wave or even eliminate it.Additionally,a well-designed generatrix shape of the center body can enhance airflow,reduce choked flow,and promote the stability of the wave structure in the flow field.展开更多
NOx sensors, as a core component of diesel engine exhaust treatment system, play an important role in exhaust emission control, which can accurately and quickly detect the NOx and O2 concentration. It has become a nec...NOx sensors, as a core component of diesel engine exhaust treatment system, play an important role in exhaust emission control, which can accurately and quickly detect the NOx and O2 concentration. It has become a necessary option for the detection of existing exhaust emission standards. At present, there is limited and scattered information on knowledge and test methods of NOx sensors, the research of NOx sensors has become a challenging research topic at home and abroad. Based on these requirements, the article systematically integrates the knowledge of principle and testing methods. First of all, through introducing functional description of NOx sensors and the basic principle of NOx sensors, the relevant scholars can have an overall understanding of the product and master the operation mode of products. Secondly, the current status of performance test bench and methods of NOx sensors were described, which can contribute to having a clear understanding of the development process. After that, a new structure of NOx sensors test bench was purposed, which contains six major units including standard gas source, gas mixing unit, analyzer measurement unit, sensor measurement unit, data processing and display unit, exhaust gas treatment unit. And the test bench was validated. The experimental results show that the test bench has the advantages of high-repeatability, high reliability and low cost. And it can realize automatic detection of multiple target values, which is worthy further promotion. Thereby, the article can contribute to the development of its technology indirectly.展开更多
The wetting behavior of slag–coke is a crucial factor influencing the permeability of the lower part of the blast furnace.However,a systematic understanding of the wetting behavior and underlying mechanisms between t...The wetting behavior of slag–coke is a crucial factor influencing the permeability of the lower part of the blast furnace.However,a systematic understanding of the wetting behavior and underlying mechanisms between titanium-containing slag and tuyere coke remains lacking.The sessile drop method was employed to explore the effects of temperature,binary basicity,FeO,and TiO_(2) contents on the wetting behavior of titanium-containing slag and tuyere coke.The results indicate that increasing the temperature enhances the adhesion and wettability of the droplet,reducing the contact angle.Meanwhile,it accelerates the chemical reactions between slag and coke,leading to faster equilibrium.Conversely,increasing slag basicity elevates the contact angle by inhibiting chemical reactions at the slag–coke interface.This inhibition reduces both contact area and depth,thereby hindering slag droplet spreading on the coke surface.The contact angle decreases as the FeO content in the slag increases.Notably,the increase in TiO_(2) content has a dual effect on slag–coke wettability.Initially,it promotes wetting by reducing surface tension and lowering the contact angle.While the TiO_(2) content exceeds 20 wt.%,Ti(C,N)forms a barrier layer at the slag–coke interface,hindering the contact between slag and coke and resulting in an increased contact angle.展开更多
Volcanic ashes are posing increasingly severer threats to the aviation safety.As the operation temperature of the turbine engine elevates,molten volcanic ash leads to the degradation of the thermal barrier coatings(TB...Volcanic ashes are posing increasingly severer threats to the aviation safety.As the operation temperature of the turbine engine elevates,molten volcanic ash leads to the degradation of the thermal barrier coatings(TBCs)and eventually catastrophic engine failure.However,the physical and chemical properties of volcanic ashes vary due to the distinct chemical compositions,rendering it extremely challenging to evaluate the effects of each ash material on the failure of TBC.Here,we proposed a new metric termed Basicity to investigate the influence of chemical composition on the melting temperature and viscosity of volcanic ashes.Artificial CaO-MgO-Al_(2)O_(3)-SiO_(2) materials(CMAS)were synthesized to simulate the wetting,spreading and corrosion behavior of volcanic ashes at 1300 ℃ on(Gd_(0.9)Yb_(0.1))2Zr_(2)O_(7)(GYbZ),a model TBC material.Our results reveal that the synthetic CMAS does not fully capture the damage caused by volcanic ash due to the difference in compositions.The viscosity and characteristic temperatures decrease as the Basicity value increases,indicating its significant impact on the fusion properties of ashes.Notably,distinct from CMAS,the unexpected presence of Fe_(2)O_(3) in volcanic ashes promotes the formation of garnet phase,conversely impedes the formation of apatite dense layer.These findings provide valuable insights into the corrosion mechanisms caused by TBC and strategies for TBC protection against volcanic ashes.展开更多
Cardiovascular diseases(CVD)and their risk factors are exerting an increasingly significant impact on public health,and the incidence rate of CVD continues to rise.This article provides an interpretation of essentials...Cardiovascular diseases(CVD)and their risk factors are exerting an increasingly significant impact on public health,and the incidence rate of CVD continues to rise.This article provides an interpretation of essentials from the newly published Annual Report on Cardiovascular Health and Diseases in China(2024),aiming to offer scientific evidence for CVD prevention,treatment,and the formulation of relevant policies.展开更多
基金supported by the National Key R&D Program of China(2019YFC1905701)the National Natural Science Foundation of China(U1960201).
文摘The effects of basicities and equilibrium temperatures on the enrichment of chromium in different mineral phases of synthesized argon-oxygen decarburization slags were investigated to understand the Cr concentrating behavior into Mg(Cr,Al)2O4 spinel phase and to determine the leaching stability of Cr-containing slag.The results showed that when the basicity decreased from 1.0 to 0.6 and temperatures decreased from 1600 to 800℃,the Cr content of amorphous phase and crystalline phase gradually decreased,with a subsequent increase in the Cr content of spinel phase.The range of Cr enrichment in spinel of slags S1,S2,and S3 is 92.03-96.89,91.63-96.36,and 90.67-95.42,respectively.The mass fraction and the size of spinel increased with the decreasing equilibrium temperatures,and the Cr leaching values decreased simultaneously.Therefore,the trend of the amount of Cr-related ions in the leachate was consistent with the trend of Cr in the amorphous phase,diopside,and akermanite.The results suggest that the lower basicity and equilibrium temperatures could be conducive to stabilizing Cr into spinel phase to minimize Cr leaching into the environment.
文摘Alumina magnesia castable crucible specimens were prepared using tabular corundum （ ≤ 5 mm ）, fused magnesia powder （ ≤0. 088 mm ） , fused spinel powder （ ≤0. 044 mm ） , and α-Al2O3. micropowder （d50 ≤0. 7 μm ） as main starting materials, batching, mixing, shaping, and drying. Slag resistance was determined by static crucible method at 1 600℃ for 3 h adopting two ladle slags with different basicities （3. 40 and 1.03 ）. The corrosion and penetration indexes and microstructure characteristics of the specimens after slag resistance test were analyzed to study the corrosion behaviors of the two slags to alumina magnesia castables. The results show that the corrosion of the low basicity slag to alumina magnesia custables is much more serious than that of the high basicity slag for that their reactions with castables form different products;for the low basicity slab,, the multi-phase coexistence of CA6 and compounds of CaO - Al2O3 -SiO2 in the materials together with volume expansion caused by the formation of CA6 intensify the slag corrosion and penetration ; for the high basicity slag, the reaction between slag and castables generates a CA2 dense layer and a large amount of in-situ MA in the interface, reducing the slag corrosion to the materials effectively.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12571549,12571592,12471463,12022113,12101573)。
文摘Vaccination is a key strategy to curb the spread of epidemics.Heterologous vaccination,unlike homologous vaccination which acts on a single target and forms a single immune barrier,covers multiple targets for broader protection.Yet,heterologous vaccination involves a complex decision process that conventional game-theoretic approaches,such as classical,evolutionary,and minority games cannot adequately capture.The parallel minority game(PMG)can handle bounded-rational,multi-choice decisions,but its application in vaccine research remains rare.In this study,we propose a vaccination-transmission coupled dynamic mechanism based on the parallel minority game and simulate it on a two-dimensional lattice.Using actual observational data and a mean-field mathematical model,we verify the effectiveness of this mechanism in simulating realistic vaccination behavior and transmission dynamics.We further analyze the impact of key parameters,such as vaccine efficacy differences and the proportion of individuals eligible for vaccine switching,on containment effectiveness.Our results demonstrate that heterologous vaccination surpasses homologous vaccination in containment effectiveness,particularly when vaccine efficacy varies significantly.This work provides a novel framework and empirical evidence for understanding individual decision-making and population-wide immunity formation in multi-vaccine settings.
文摘Agricultural development is regarded as the most important foundation of China’s modernisation.According to the Recommendations of the CPC Central Committee for Formulating the 15th Five-Year Plan for National Economic and Social Development(2026–2030),issues related to agriculture,rural areas and rural residents should be given top priority.In the coming years,China will promote coordinated urban and rural development,continue to consolidate and expand the achievements of poverty alleviation,ensure basic modern living conditions in rural areas,and accelerate progress in building a strong agricultural sector.
基金supported by the National Natural Science Foundation of China,Nos.81870921(to YW),81974179(to ZZ),82271320(to ZZ),82071284(to YT)National Key R&D Program of China,No.2022YFA1603600(to ZZ),2019YFA0112000(to YT)+1 种基金Scientific Research and Innovation Program of Shanghai Education Commission,No.2019-01-07-00-02-E00064(to GYY)Scientific and Technological Innovation Act Program of Shanghai Science and Technology Commission,No.20JC1411900(to GYY).
文摘AAV-PHP.eB is an artificial adeno-associated virus(AAV)that crosses the blood-brain barrier and targets neurons more efficiently than other AAVs when administered systematically.While AAV-PHP.eB has been used in various disease models,its cellular tropism in cerebrovascular diseases remains unclear.In the present study,we aimed to elucidate the tropism of AAV-PHP.eB for different cell types in the brain in a mouse model of ischemic stroke and evaluate its effectiveness in mediating basic fibroblast growth factor(bFGF)gene therapy.Mice were injected intravenously with AAV-PHP.eB either 14 days prior to(pre-stroke)or 1 day following(post-stroke)transient middle cerebral artery occlusion.Notably,we observed a shift in tropism from neurons to endothelial cells with post-stroke administration of AAV-PHP.eB-mNeonGreen(mNG).This endothelial cell tropism correlated strongly with expression of the endothelial membrane receptor lymphocyte antigen 6 family member A(Ly6A).Furthermore,AAV-PHP.eB-mediated overexpression of bFGF markedly improved neurobehavioral outcomes and promoted long-term neurogenesis and angiogenesis post-ischemic stroke.Our findings underscore the significance of considering potential tropism shifts when utilizing AAV-PHP.eB-mediated gene therapy in neurological diseases and suggest a promising new strategy for bFGF gene therapy in stroke treatment.
文摘Objectives:The current treatment options and therapeutic targets for triple-negative breast cancer(TNBC),an aggressive subtype of breast cancer(BrCA),are limited.This study aimed to identify novel biomarkers and transcriptional regulatory networks(TRN)inherent in TNBC samples.Methods:We analyzed pan-cancer BrCA datasets from The Cancer Genome Atlas(TCGA)to compare triple-positive breast cancer(TPBC)with TNBC.TRN algorithms and virtual inference of protein-enriched regulon(VIPER)were used to identify master regulators and their target genes.Utilizing TNBC cells(MDA-MB-231 and MDA-MB-468),we validated the relationship of nuclear factor erythroid 2-like 3(NFE2L3)and basic helix-loop-helix family member E 40(BHLHE40)by performing a luciferase assay.The expression levels of these targets were measured after transfections with plasmid and siRNA via qRT-PCR and western blots.The effect of these genes on cell proliferation and migration was studied using phenotypic assays.Results:Using computational approaches,we identified NFE2L3 as a master regulator with BHLHE40 as its target gene.NFE2L3 protein binds to the promoter region of BHLHE40 and regulates its transcriptional activity.Additionally,silencing and overexpressing NFE2L3 and BHLHE40 in TNBC cell lines MDA-MB-231 and MDA-MB-468 showed that NFE2L3 directly regulates BHLHE40 at both transcriptional and translational levels.We found that BHLHE40 requires NFE2L3 for cell proliferation and migration in TNBC.Conclusion:These findings underscore the significance of NFE2L3 and BHLHE40 in TNBC,highlighting NFE2L3’s role in regulating the oncogenic activity of BHLHE40 in TNBC cells.
基金supported by the National Natural Science Foundation of China(Nos.U20A2069,62376234 and 123B2037)the Advanced Aero-Power Innovation Workstation,China(No.HKCX2024-01-017)。
文摘The selection of an appropriate basic detonation wave flow field is crucial for improving the performance and geometric design of standing detonation vehicles.This paper employs a detailed chemical reaction model and solves the unsteady axisymmetric Euler equation to study the characteristics of the Axisymmetric Inward Turning Curved Detonation Wave(AIT-CDW)flow field and the parameters affecting the stability of the wave system structure of AIT-CDW flow field.The numerical results demonstrate a radial compression effect in the AIT-CDW flow field.This effect causes the detonation wave to have a shorter initiation length than oblique detonation wave flow field and the detonation wave angle to gradually increase with the flow direction postdetonation.The AIT-CDW flow field is confined space,making it prone to normal detonation waves when the detonation wave reflects from the wall.This phenomenon is detrimental to the stability of the wave system structure in the flow field.It has been observed that increasing the center body radius and decreasing the fuel equivalent ratio can effectively reduce the height of the normal detonation wave or even eliminate it.Additionally,a well-designed generatrix shape of the center body can enhance airflow,reduce choked flow,and promote the stability of the wave structure in the flow field.
文摘NOx sensors, as a core component of diesel engine exhaust treatment system, play an important role in exhaust emission control, which can accurately and quickly detect the NOx and O2 concentration. It has become a necessary option for the detection of existing exhaust emission standards. At present, there is limited and scattered information on knowledge and test methods of NOx sensors, the research of NOx sensors has become a challenging research topic at home and abroad. Based on these requirements, the article systematically integrates the knowledge of principle and testing methods. First of all, through introducing functional description of NOx sensors and the basic principle of NOx sensors, the relevant scholars can have an overall understanding of the product and master the operation mode of products. Secondly, the current status of performance test bench and methods of NOx sensors were described, which can contribute to having a clear understanding of the development process. After that, a new structure of NOx sensors test bench was purposed, which contains six major units including standard gas source, gas mixing unit, analyzer measurement unit, sensor measurement unit, data processing and display unit, exhaust gas treatment unit. And the test bench was validated. The experimental results show that the test bench has the advantages of high-repeatability, high reliability and low cost. And it can realize automatic detection of multiple target values, which is worthy further promotion. Thereby, the article can contribute to the development of its technology indirectly.
基金supported by the Postdoctor Project of Hubei Province(2024HBBHCXA074)National Natural Science Foundation of China(51974212)+2 种基金China Baowu Low Carbon Metallurgy Innovation Foundation(BWLCF202116)Foundation of Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking(NPISlab25-03)Science and Technology Major Project of Wuhan(2023020302020572).
文摘The wetting behavior of slag–coke is a crucial factor influencing the permeability of the lower part of the blast furnace.However,a systematic understanding of the wetting behavior and underlying mechanisms between titanium-containing slag and tuyere coke remains lacking.The sessile drop method was employed to explore the effects of temperature,binary basicity,FeO,and TiO_(2) contents on the wetting behavior of titanium-containing slag and tuyere coke.The results indicate that increasing the temperature enhances the adhesion and wettability of the droplet,reducing the contact angle.Meanwhile,it accelerates the chemical reactions between slag and coke,leading to faster equilibrium.Conversely,increasing slag basicity elevates the contact angle by inhibiting chemical reactions at the slag–coke interface.This inhibition reduces both contact area and depth,thereby hindering slag droplet spreading on the coke surface.The contact angle decreases as the FeO content in the slag increases.Notably,the increase in TiO_(2) content has a dual effect on slag–coke wettability.Initially,it promotes wetting by reducing surface tension and lowering the contact angle.While the TiO_(2) content exceeds 20 wt.%,Ti(C,N)forms a barrier layer at the slag–coke interface,hindering the contact between slag and coke and resulting in an increased contact angle.
基金financially supported by the Nature Science Foun-dations of China(NSFC)(Nos.52401071 andU21B2052)China National Postdoctoral Program for Innovative Talents(No.BX20240459).
文摘Volcanic ashes are posing increasingly severer threats to the aviation safety.As the operation temperature of the turbine engine elevates,molten volcanic ash leads to the degradation of the thermal barrier coatings(TBCs)and eventually catastrophic engine failure.However,the physical and chemical properties of volcanic ashes vary due to the distinct chemical compositions,rendering it extremely challenging to evaluate the effects of each ash material on the failure of TBC.Here,we proposed a new metric termed Basicity to investigate the influence of chemical composition on the melting temperature and viscosity of volcanic ashes.Artificial CaO-MgO-Al_(2)O_(3)-SiO_(2) materials(CMAS)were synthesized to simulate the wetting,spreading and corrosion behavior of volcanic ashes at 1300 ℃ on(Gd_(0.9)Yb_(0.1))2Zr_(2)O_(7)(GYbZ),a model TBC material.Our results reveal that the synthetic CMAS does not fully capture the damage caused by volcanic ash due to the difference in compositions.The viscosity and characteristic temperatures decrease as the Basicity value increases,indicating its significant impact on the fusion properties of ashes.Notably,distinct from CMAS,the unexpected presence of Fe_(2)O_(3) in volcanic ashes promotes the formation of garnet phase,conversely impedes the formation of apatite dense layer.These findings provide valuable insights into the corrosion mechanisms caused by TBC and strategies for TBC protection against volcanic ashes.
文摘Cardiovascular diseases(CVD)and their risk factors are exerting an increasingly significant impact on public health,and the incidence rate of CVD continues to rise.This article provides an interpretation of essentials from the newly published Annual Report on Cardiovascular Health and Diseases in China(2024),aiming to offer scientific evidence for CVD prevention,treatment,and the formulation of relevant policies.
