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 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.
