The Mg-Gd-Y-Zn-Zr(GWZ)alloy containing a long-period ordered stacking(LPSO)phase fabricated by Wire arc additive manufacturing(WAAM)shows substantial potential in the aerospace and automotive industries.In this work,M...The Mg-Gd-Y-Zn-Zr(GWZ)alloy containing a long-period ordered stacking(LPSO)phase fabricated by Wire arc additive manufacturing(WAAM)shows substantial potential in the aerospace and automotive industries.In this work,Mg-9Gd-4Y-1Zn-0.4Zr(wt%)single-layer and multilayer components with high-forming-quality were fabricated using WAAM based on cold metal transfer(WAAM-CMT).The deposition parameters were optimized,achieving better deposition morphology and surface quality.The layer-by-layer cyclic microstructure includes remelting zone(RMZ)and non-remelting zone(NRZ),which consisted of α-Mg matrix,blocky LPSO phase,and eutectic phase.The average grain size were 26.8μm in RMZ and 39.3μm in NRZ,and the volume fraction of secondary phases was around 8%,remaining consistent across different layers.The coarse-fine-grain alternating structure generated hetero deformation induced(HDI)strengthening,while at the same time caused the fracture occurring between the NRZ and RMZ due to the weak interlayer bonding.The thermally stabilized blocky LPSO phase played an effective role on inhibiting grain growth during the solid-solution treatment.The specimen achieved highest isotropic mechanical properties after optimized heat treatment with yield strength,ultimate tensile strength,and elongation higher than 220 MPa,370 MPa,and 8.0%,respectively.The GWZ alloys fabricated by WAAM with great isotropic strength-ductility-synergy are promising candidates to replace the conventionally cast counterparts.展开更多
To enhance methane production efficiency in lignite anaerobic digestion and explore new ways for residual sludge utilization, this study employed the co-fermentation of lignite and residual sludge for biomethane conve...To enhance methane production efficiency in lignite anaerobic digestion and explore new ways for residual sludge utilization, this study employed the co-fermentation of lignite and residual sludge for biomethane conversion. The bacterial colony structure, metabolic pathways, and interactions between residual sludge and lignite in anaerobic methanogenic fermentation with different mass ratios were analyzed using macrogenomics sequencing. This study aimed to explore the mechanisms involved in the co-anaerobic fermentation of lignite and residual sludge. The results indicated that the addition of sludge enhanced the metabolic pathways in hydrolysis acidification, hydrogen-acetic acid production, and methanation phases. Notably, the enhancement of acetate- and carbon dioxide-nutrient metabolic pathways was more pronounced, with increased activity observed in related enzymes such as acetic acid kinase (k00925) and acetyl coenzyme synthetase (K01895). This increased enzymatic activity facilitated the microbial conversion of biomethane. The results of the study indicated that the sludge exhibited a promotional effect on the methane produced through the anaerobic fermentation of lignite, providing valuable insights for lignite and residual sludge resource utilization.展开更多
For expedited transportation,vehicular tunnels are often designed as two adjacent tunnels,which frequently experience dynamic stress waves from various orientations during blasting excavation.To analyze the impact of ...For expedited transportation,vehicular tunnels are often designed as two adjacent tunnels,which frequently experience dynamic stress waves from various orientations during blasting excavation.To analyze the impact of dynamic loading orientation on the stability of the twin-tunnel,a split Hopkinson pressure bar(SHPB)apparatus was used to conduct a dynamic test on the twin-tunnel specimens.The two tunnels were rotated around the specimen’s center to consider the effect of dynamic loading orientation.LS-DYNA software was used for numerical simulation to reveal the failure properties and stress wave propagation law of the twin-tunnel specimens.The findings indicate that,for a twin-tunnel exposed to a dynamic load from different orientations,the crack initiation position appears most often at the tunnel corner,tunnel spandrel,and tunnel floor.As the impact direction is created by a certain angle(30°,45°,60°,120°,135°,and 150°),the fractures are produced in the middle of the line between the left tunnel corner and the right tunnel spandrel.As the impact loading angle(a)is 90°,the tunnel sustains minimal damage,and only tensile fractures form in the surrounding rocks.The orientation of the impact load could change the stress distribution in the twin-tunnel,and major fractures are more likely to form in areas where the tensile stress is concentrated.展开更多
Objective Acute lung injury(ALI)is an acute clinical syndrome characterized by uncontrolled inflammation response,which causes high mortality and poor prognosis.The present study determined the protective effect and u...Objective Acute lung injury(ALI)is an acute clinical syndrome characterized by uncontrolled inflammation response,which causes high mortality and poor prognosis.The present study determined the protective effect and underlying mechanism of Periplaneta americana extract(PAE)against lipopolysaccharide(LPS)-induced ALI.Methods The viability of MH-S cells was measured by MTT.ALI was induced in BALB/c mice by intranasal administration of LPS(5 mg/kg),and the pathological changes,oxidative stress,myeloperoxidase activity,lactate dehydrogenase activity,inflammatory cytokine expression,edema formation,and signal pathway activation in lung tissues and bronchoalveolar lavage fluid(BALF)were examined by H&E staining,MDA,SOD and CAT assays,MPO assay,ELISA,wet/dry analysis,immunofluorescence staining and Western blotting,respectively.Results The results revealed that PAE obviously inhibited the release of proinflammatory TNF-α,IL-6 and IL-1βby suppressing the activation of MAPK/Akt/NF-κB signaling pathways in LPS-treated MH-S cells.Furthermore,PAE suppressed the neutrophil infiltration,permeability increase,pathological changes,cellular damage and death,pro-inflammatory cytokines expression,and oxidative stress upregulation,which was associated with its blockage of the MAPK/Akt/NF-κB pathway in lung tissues of ALI mice.Conclusion PAE may serve as a potential agent for ALI treatment due to its anti-inflammatory and anti-oxidative properties,which correlate to the blockage of the MAPK/NF-κB and AKT signaling pathways.展开更多
Carbon capture,utilization,and storage(CCUS)is considered one of the most effective measures to achieve net-zero carbon emissions by 2050,and low-rank coal reservoirs are commonly recognized as potential CO_(2)storage...Carbon capture,utilization,and storage(CCUS)is considered one of the most effective measures to achieve net-zero carbon emissions by 2050,and low-rank coal reservoirs are commonly recognized as potential CO_(2)storage sites for carbon sequestration.To evaluate the geological CO_(2)sequestration potential of the low-rank coal reservoirs in the southern margin of the Junggar Basin,multiple experiments were performed on coal samples from that area,including high-pressure mercury porosimetry,low-temperature N2 adsorption,overburden porosity and permeability measurements,and high-pressure CH4 and CO_(2)isothermal adsorption measurements.Combined with the geological properties of the potential reservoir,including coal seam development and hydrodynamic characteristics,the areas between Santun River and Sigong River in the Junggar Basin were found to be suitable for CO_(2)sequestration.Consequently,the coal-bearing strata from Santun River to Sigong River can be defined as“potentially favorable areas for CO_(2)eequetfraiion”To better guide the future field test of CO_(2)storage in these areas,three CO_(2)sequestration modes were defined:1)the broad syncline and faulted anticline mode;2)the monoclinic mode;3)the syncline and strike-slip fault mode.展开更多
基金supported by the National Key Research and Development Program of China(No.2021YFB3701004)National Natural Science Foundation of China(No.52071211)Joint Research Center of Advanced Aerospace Technology of Shanghai Academy of Spaceflight Technology-Shanghai Jiao Tong University(No.USCAST2020-1).
文摘The Mg-Gd-Y-Zn-Zr(GWZ)alloy containing a long-period ordered stacking(LPSO)phase fabricated by Wire arc additive manufacturing(WAAM)shows substantial potential in the aerospace and automotive industries.In this work,Mg-9Gd-4Y-1Zn-0.4Zr(wt%)single-layer and multilayer components with high-forming-quality were fabricated using WAAM based on cold metal transfer(WAAM-CMT).The deposition parameters were optimized,achieving better deposition morphology and surface quality.The layer-by-layer cyclic microstructure includes remelting zone(RMZ)and non-remelting zone(NRZ),which consisted of α-Mg matrix,blocky LPSO phase,and eutectic phase.The average grain size were 26.8μm in RMZ and 39.3μm in NRZ,and the volume fraction of secondary phases was around 8%,remaining consistent across different layers.The coarse-fine-grain alternating structure generated hetero deformation induced(HDI)strengthening,while at the same time caused the fracture occurring between the NRZ and RMZ due to the weak interlayer bonding.The thermally stabilized blocky LPSO phase played an effective role on inhibiting grain growth during the solid-solution treatment.The specimen achieved highest isotropic mechanical properties after optimized heat treatment with yield strength,ultimate tensile strength,and elongation higher than 220 MPa,370 MPa,and 8.0%,respectively.The GWZ alloys fabricated by WAAM with great isotropic strength-ductility-synergy are promising candidates to replace the conventionally cast counterparts.
文摘To enhance methane production efficiency in lignite anaerobic digestion and explore new ways for residual sludge utilization, this study employed the co-fermentation of lignite and residual sludge for biomethane conversion. The bacterial colony structure, metabolic pathways, and interactions between residual sludge and lignite in anaerobic methanogenic fermentation with different mass ratios were analyzed using macrogenomics sequencing. This study aimed to explore the mechanisms involved in the co-anaerobic fermentation of lignite and residual sludge. The results indicated that the addition of sludge enhanced the metabolic pathways in hydrolysis acidification, hydrogen-acetic acid production, and methanation phases. Notably, the enhancement of acetate- and carbon dioxide-nutrient metabolic pathways was more pronounced, with increased activity observed in related enzymes such as acetic acid kinase (k00925) and acetyl coenzyme synthetase (K01895). This increased enzymatic activity facilitated the microbial conversion of biomethane. The results of the study indicated that the sludge exhibited a promotional effect on the methane produced through the anaerobic fermentation of lignite, providing valuable insights for lignite and residual sludge resource utilization.
基金supported by the National Natural Science Foundation of China(Grant Nos.52204104 and U19A2098)the Science and Technology Department of Sichuan Province,China(Grant No.2023YFH0022).
文摘For expedited transportation,vehicular tunnels are often designed as two adjacent tunnels,which frequently experience dynamic stress waves from various orientations during blasting excavation.To analyze the impact of dynamic loading orientation on the stability of the twin-tunnel,a split Hopkinson pressure bar(SHPB)apparatus was used to conduct a dynamic test on the twin-tunnel specimens.The two tunnels were rotated around the specimen’s center to consider the effect of dynamic loading orientation.LS-DYNA software was used for numerical simulation to reveal the failure properties and stress wave propagation law of the twin-tunnel specimens.The findings indicate that,for a twin-tunnel exposed to a dynamic load from different orientations,the crack initiation position appears most often at the tunnel corner,tunnel spandrel,and tunnel floor.As the impact direction is created by a certain angle(30°,45°,60°,120°,135°,and 150°),the fractures are produced in the middle of the line between the left tunnel corner and the right tunnel spandrel.As the impact loading angle(a)is 90°,the tunnel sustains minimal damage,and only tensile fractures form in the surrounding rocks.The orientation of the impact load could change the stress distribution in the twin-tunnel,and major fractures are more likely to form in areas where the tensile stress is concentrated.
基金This study was funded in part by the National Natural Science Foundation of China(Nos.31861143050,31772476 and 31911530077).
文摘Objective Acute lung injury(ALI)is an acute clinical syndrome characterized by uncontrolled inflammation response,which causes high mortality and poor prognosis.The present study determined the protective effect and underlying mechanism of Periplaneta americana extract(PAE)against lipopolysaccharide(LPS)-induced ALI.Methods The viability of MH-S cells was measured by MTT.ALI was induced in BALB/c mice by intranasal administration of LPS(5 mg/kg),and the pathological changes,oxidative stress,myeloperoxidase activity,lactate dehydrogenase activity,inflammatory cytokine expression,edema formation,and signal pathway activation in lung tissues and bronchoalveolar lavage fluid(BALF)were examined by H&E staining,MDA,SOD and CAT assays,MPO assay,ELISA,wet/dry analysis,immunofluorescence staining and Western blotting,respectively.Results The results revealed that PAE obviously inhibited the release of proinflammatory TNF-α,IL-6 and IL-1βby suppressing the activation of MAPK/Akt/NF-κB signaling pathways in LPS-treated MH-S cells.Furthermore,PAE suppressed the neutrophil infiltration,permeability increase,pathological changes,cellular damage and death,pro-inflammatory cytokines expression,and oxidative stress upregulation,which was associated with its blockage of the MAPK/Akt/NF-κB pathway in lung tissues of ALI mice.Conclusion PAE may serve as a potential agent for ALI treatment due to its anti-inflammatory and anti-oxidative properties,which correlate to the blockage of the MAPK/NF-κB and AKT signaling pathways.
文摘Carbon capture,utilization,and storage(CCUS)is considered one of the most effective measures to achieve net-zero carbon emissions by 2050,and low-rank coal reservoirs are commonly recognized as potential CO_(2)storage sites for carbon sequestration.To evaluate the geological CO_(2)sequestration potential of the low-rank coal reservoirs in the southern margin of the Junggar Basin,multiple experiments were performed on coal samples from that area,including high-pressure mercury porosimetry,low-temperature N2 adsorption,overburden porosity and permeability measurements,and high-pressure CH4 and CO_(2)isothermal adsorption measurements.Combined with the geological properties of the potential reservoir,including coal seam development and hydrodynamic characteristics,the areas between Santun River and Sigong River in the Junggar Basin were found to be suitable for CO_(2)sequestration.Consequently,the coal-bearing strata from Santun River to Sigong River can be defined as“potentially favorable areas for CO_(2)eequetfraiion”To better guide the future field test of CO_(2)storage in these areas,three CO_(2)sequestration modes were defined:1)the broad syncline and faulted anticline mode;2)the monoclinic mode;3)the syncline and strike-slip fault mode.
