In this study,a novel polysaccharide GPA-G 2-H was derived from ginseng.Furthermore,the coherent study of its structural characteristics,fermented characteristics in vitro,as well as antioxidant mechanism of fermented...In this study,a novel polysaccharide GPA-G 2-H was derived from ginseng.Furthermore,the coherent study of its structural characteristics,fermented characteristics in vitro,as well as antioxidant mechanism of fermented product FGPA-G 2-H on Aβ25-35-induced PC 12 cells were explored.The structure of GPA-G 2-H was determined by means of zeta potential analysis,FTIR,HPLC,XRD,GC-MS and NMR.The backbone of GPA-G 2-H was mainly composed of→4)-α-D-Glcp-(1→with branches substituted at O-3.Notably,GPA-G 2-H was degraded by intestinal microbiota in vitro with total sugar content and pH value decreasing,and short-chain fatty acids(SCFAs)increasing.Moreover,GPA-G 2-H significantly promoted the proliferation of Lactobacillus,Muribaculaceae and Weissella,thereby making positive alterations in intestinal microbiota composition.Additionally,FGPA-G 2-H activated the Nrf 2/HO-1 signaling pathway,enhanced HO-1,NQO 1,SOD and GSH-Px,while inhabited Keap 1,MDA and LDH,which alleviated Aβ-induced oxidative stress in PC 12 cells.These provide a solid theoretical basis for the further development of ginseng polysaccharides as functional food and antioxidant drugs.展开更多
To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content ...To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content in coal)catalysts were prepared by the incipient wetness impregnation method,followed by acid washing to remove calcium-containing minerals.Comprehensive characterization and low-temperature denitrification tests revealed that calcite-induced structural modulation of coal-derived AC significantly enhances catalytic activity.Specifically,NO conversion increased from 88.3%of Mn-Ce/De-AC to 91.7%of Mn-Ce/De-AC-1CaCO_(3)(210℃).The improved SCR denitrification activity results from the enhancement of physicochemical properties including higher Mn^(4+)content and Ce^(4+)/Ce^(3+)ratio,an abundance of chemisorbed oxygen and acidic sites,which could strengthen the SCR reaction pathways(richer NH_(3)activated species and bidentate nitrate active species).Therefore,NO removal is enhanced.展开更多
To address the neglect of seismic performance in conventional double-girder bridge crane optimization,this paper introduces a time-history analysis-based seismic optimization methodology for crane structures.Using a 2...To address the neglect of seismic performance in conventional double-girder bridge crane optimization,this paper introduces a time-history analysis-based seismic optimization methodology for crane structures.Using a 25-t nuclear power crane as a case study,a bridge frame finite element model is established and validated through static analysis,confirming its accurate representation of the physical entity’s mechanical behavior.Furthermore,with bridge mass reduction as the objective and structural strength,stiffness,stability,and seismic mechanical performance as constraints,an optimization model is developed employing the Whale Optimization Algorithm(WOA).展开更多
Exogenous organic input impacts soil phosphorus transformation.Meanwhile,dissolved organic matter(DOM)is crucial for biogeochemical functions.Nevertheless,the interaction between the structural composition of DOM and ...Exogenous organic input impacts soil phosphorus transformation.Meanwhile,dissolved organic matter(DOM)is crucial for biogeochemical functions.Nevertheless,the interaction between the structural composition of DOM and phosphorus during the soil formation process of phosphogypsum(PG)remains unknown.This study explores the interaction between the structural composition of DOM and phosphorus in enhanced PG under the participation of fungal microorganisms through different application amounts of exogenous organic matter and culture time.Results show that application of exogenous organic matter led to varying degrees of increase in dissolved organic carbon(DOC)concentration and humification extent in the soil-like substrate.Additionally,the relative abundance of protein-like component C3 exhibited a trend of initial increase followed by decline over time.The contents of available phosphorus(AP),microbial biomass phosphorus(MBP),and active phosphorus pools(Active-P)in the soil-like substrate are all enhanced overall.Furthermore,a significant correlation exists between DOC and AP as well as MBP.This suggests that DOM is a crucial factor in enhancing the phosphorus availability of the soil-like substrate.The enrichment of known phosphate-solubilizing fungi in culturing favors the decomposition,activation and utilization of hard-to-mineralize phosphorus components in the soil-like substrate.These findings help understand DOM’s biogeochemical behavior and offer insights into PG utilization and the sustainable development of China’s phosphorus industry.展开更多
The Kumkol Basin,situated in the northern margin of the Qinghai-Xizang Plateau,provides a unique window into understanding the dynamic mechanisms driving the plateau’s northern expansion.However,its formation and tec...The Kumkol Basin,situated in the northern margin of the Qinghai-Xizang Plateau,provides a unique window into understanding the dynamic mechanisms driving the plateau’s northern expansion.However,its formation and tectonic evolution remain poorly understood due to limited geophysical data in this region.In this study,we computed cross-correlations for the TT components of station-pairs with high signal-to-noise ratios to extract Love wave waveforms and further performed Lovewave ambient noise tomography to image the upper crustal shear-wave velocity structure of the Kumkol basin down to 10 km depth.Our seismic velocity model reveals that the Kumkol Basin has a sedimentary thickness exceeding 8 km,with its center located near the Arka Mountain on the southern side.This suggests that the basin was likely formed as a foreland basin in response to the uplift of the Qiman Tagh Mountain to the north.Additionally,integrated with seismic reflection data,our seismic velocity model images a detachment fault at the basin basement depth.We inferred that the Kumkol Anticlinorium at the basin’s center have been produced by multiple thrust faults converging into this detachment fault at 8–10 km depth following the Early to Middle Miocene uplift of the Qiman Tagh Mountain.This structural configuration indicates pulsed basinward deformation since the late Miocene,likely reflecting a tectonic regime shift from extrusion to distributed shortening in the northern Qinghai-Xizang Plateau.Our findings provide a high-resolution velocity model of the Kumkol Basin,offering critical insights into its structural evolution and supporting future resource exploration in this underexplored region.展开更多
In igneous-intruded coal seams,coal undergoes significant metamorphism,which critically alters its pore structure and oxygen consumption dynamics,thereby elevating its spontaneous combustion tendency.This study invest...In igneous-intruded coal seams,coal undergoes significant metamorphism,which critically alters its pore structure and oxygen consumption dynamics,thereby elevating its spontaneous combustion tendency.This study investigates the specific surface area,pore volume,structure complexity/connectivity,heterogeneity/local features of pore size distribution,and oxygen consumption dynamics of igneous metamorphic coal through N_(2)/CO_(2) isothermal adsorption tests and low-temperature oxidation experiments,and elucidates the influence mechanisms of pore structure evolution on oxygen consumption dynamics during low-temperature oxidation.With increasing metamorphic degree,igneous metamorphic coal exhibits a more pronounced reduction in specific surface area during oxidation,while the increase in structure complexity due to coal-oxygen reactions is suppressed.Thermally metamorphic coal demonstrates accelerated oxygen consumption,with oxidation amplifying the difference in reaction rates compared to raw coal.Key mechanisms include oxidation-induced reduction in mesopore complexity and micropore volume,decreased dominance of small-pore-volume apertures,and increased heterogeneity,collectively leading to a lower half-oxygen-consuming temperature and steeper oxygen consumption curves.Simultaneously,increased pore volume/complexity and reduced uniformity/connectivity act synergistically to enhance oxygen consumption capacity,highlighting the coupling between pore structure evolution and oxidation behavior in igneous metamorphic coal.This study provides theoretical insights into the pore-oxygen coupling mechanisms governing coal spontaneous combustion in igneous intrusion areas.展开更多
A detailed understanding of seismicity originating from the Nanga Parbat syntaxis in the northwestern Himalaya is crucial for characterizing the active fault systems and associated neotectonic processes in the region....A detailed understanding of seismicity originating from the Nanga Parbat syntaxis in the northwestern Himalaya is crucial for characterizing the active fault systems and associated neotectonic processes in the region.Continuous earthquake monitoring through local seismic stations enables high-precision results by constraining the velocity structure.In this study,seismogram data from 244 small-magnitude earthquakes are analyzed to delineate the crustal thickness and investigate the source mechanisms beneath the Nanga Parbat syntaxis.The results are achieved with the application of Coupled Hypocenter Velocity Inversion(CHVI)analysis and Time Domain Moment Tensor(TDMT)analysis.The velocity inversion suggests that the Moho discontinuity lies at 60 km depth with an average vP/vS ratio of 1.735±0.017.The minimum 1D velocity model obtained through velocity inversion with least RMS error is further utilized in determining the source mechanism solution.In contrast to earlier studies,which highlighted strike-slip displacement accompanied by reverse dip-slip components,the present research provides a revised interpretation.The moment tensor analysis conducted in this study provides evidence of transtensional deformation associated with neotectonics,attributed to the presence of multiple shear zones.The results of the source mechanism for the selected earthquakes unveiled that the oblique-slip deformation is significantly controlled by the shear stresses coupled with the normal component of dip-slip movement.This is further supported by the higher values of the doublecouple moment tensor(85%),which indicate shear deformation,while the positive value of the compensated linear vector dipole(15%)confirms the presence of a normal component.The coexistence of transpressive and transtensive stresses,together with shallow hypocentral depths and high-amplitude tangential waveforms,can potentially cause devastating impacts in the surroundings of the Nanga Parbat syntaxis.展开更多
This study investigates the thermo–mechanical behavior of C40 concrete and reinforced concrete subjected to elevated temperatures up to 700℃by integrating experimental testing and advanced numerical modeling.A tempe...This study investigates the thermo–mechanical behavior of C40 concrete and reinforced concrete subjected to elevated temperatures up to 700℃by integrating experimental testing and advanced numerical modeling.A temperature-indexed Concrete Damage Plasticity(CDP)framework incorporating bond–slip effects was developed in Abaqus to capture both global stress–strain responses and localized damage evolution.Uniaxial compression tests on thermally exposed cylinders provided residual strength data and failure observations for model calibration and validation.Results demonstrated a distinct two-stage degradation regime:moderate stiffness and strength reduction up to~400℃,followed by sharp deterioration beyond 500℃–600℃,with residual capacity at 700℃reduced to~20%–25%of the ambient value.Strain–damage analyses revealed the formation of a peripheral tensile strain band,which thickened and propagated inward with increasing temperature,governing crack initiation and cover spalling.Supplemental analyses highlighted that transverse reinforcement improved ductility and damage distribution at moderate temperatures(~300℃),but bond deterioration and steel softening beyond~600℃substantially diminished confinement effectiveness.The proposed CDP model accurately reproduced experimental stress–strain curves(R^(2)≈0.94–0.98 up to 600℃;≈0.90 at 700℃),with peak stress errors within 7%–10%and energy absorption captured within~12%.These findings confirm the robustness of the temperature-indexed CDP framework for simulating fire-damaged reinforced concrete and provide practical guidelines for post-fire assessment,spalling detection,and fire-resilient design of structural members.展开更多
Aiming at the problem of dynamic instability of hard-brittle jointed rock surrounding in deep tunnel/roadway engineering,combining with the support concepts of"coupling rigidity with flexibility"and"ove...Aiming at the problem of dynamic instability of hard-brittle jointed rock surrounding in deep tunnel/roadway engineering,combining with the support concepts of"coupling rigidity with flexibility"and"overcoming rigidity by flexibility",the prevention and control method with"rigid-flexible coupling(R-F-C)"was put forward.Through numerical simulation calculation,the impact damage process,acoustic emission(AE)evolution characteristics,and element stress/displacement evolution characteristics of unsupported surrounding rock structure model,rigid supporting surrounding rock structure model,and"R-F-C"supporting surrounding rock structure model under horizontal bidirectional impact loading were compared and analyzed.Based on the theory of stress wave propagation,the dynamic instability catastrophe mechanism of three kinds of supporting structure models induced by horizontal bidirectional impact loading was revealed.Based on the Mohr-Coulomb strength theory,the stress discrimination methods of dynamic catastrophe of surrounding rock induced by horizontal bidirectional impact loading under three kinds of supporting structures were proposed.Combined with the above numerical simulation study,the explosion impact physical and mechanical test of"R-F-C"surrounding rock supporting plate structure was further designed and carried out.Finally,combined with the"conceptual model of ball-cliff potential energy instability",the energy driving theory and energy transformation mechanism of impact-induced rockburst under three kinds of supporting structures were discussed deeply.The research results provided a scientific basis for further promoting the effective application of"R-F-C"supporting structure in the prevention and control of dynamic instability of deep tunnel/roadway surrounding rock.展开更多
Background:Tertiary lymphoid structures(TLSs)promote antitumor immunity and predict favorable immunotherapy outcomes in breast cancer.The study aimed to investigate how Tryptophan 2,3-dioxygenase(TDO2)-associated tryp...Background:Tertiary lymphoid structures(TLSs)promote antitumor immunity and predict favorable immunotherapy outcomes in breast cancer.The study aimed to investigate how Tryptophan 2,3-dioxygenase(TDO2)-associated tryptophan metabolism influences TLS maturation and B cell class switching in breast cancer.Methods:Bulk transcriptomic data from The Cancer Genome Atlas-Breast Invasive Carcinoma(TCGA-BRCA,n=1055)were analyzed using Gene Set Variation Analysis(GSVA)-based metabolic scoring,immune deconvolution,and TLS quantification.Single-cell RNA sequencing(scRNA-seq,n=26)and spatial transcriptomics(n=1)were applied to map TDO2 expression and TLS spatial organization.Validation was performed by immunohistochemistry(n=38)and multiplex immunofluorescence(n=12).Results:We identified that elevated tryptophan metabolism was predominantly enriched in the Luminal A subtype and delineates an immune-cold phenotype with less immunogenicity,associated with a distinct immune-dominant cellular microenvironment,particularly enriched in T and plasma cells.High expression of the tryptophan-metabolizing enzyme TDO2 was significantly enriched in TLS-low tumors and negatively correlated with TLS maturation signatures.Functional enrichment revealed suppressed B cell class switching and attenuated C-X-C motif chemokine ligand 9(CXCL9)expression in TLS-deficient tumors.Spatial transcriptomics and hotspot analysis demonstrated an inverse spatial correlation between TDO2 expression and TLS core components.Tumors with high tryptophan metabolism showed decreased cluster of differentiation 20(CD20)^(+)and CXCL9^(+)cell infiltration within TLS zones.Tumors with strong TDO2-kynurenine activity displayed impaired TLS organization and attenuated humoral immunity.Conditional spatial co-occurrence modeling confirmed reduced proximity between tryptophan metabolism hotspots and TLS-related immune features.Conclusion:In conclusion,our findings suggest that TDO2-associated tryptophan metabolism is linked to impaired TLS maturation and suppressed B cell class switching in breast cancer.Targeting the TDO2-kynurenine axis may represent a promising strategy to restore TLS formation and enhance immunotherapy responsiveness in breast cancer.展开更多
Brazing filler metals are widely applied,which serve as an industrial adhesive in the joining of dissimilar structures.With the continuous emergence of new structures and materials,the demand for novel brazing filler ...Brazing filler metals are widely applied,which serve as an industrial adhesive in the joining of dissimilar structures.With the continuous emergence of new structures and materials,the demand for novel brazing filler metals is ever-increasing.It is of great significance to investigate the optimized composition design methods and to establish systematic design guidelines for brazing filler metals.This study elucidated the fundamental rules for the composition design of brazing filler metals from a three-dimensional perspective encompassing the basic properties of applied brazing filler metals,formability and processability,and overall cost.The basic properties of brazing filler metals refer to their mechanical properties,physicochemical properties,electromagnetic properties,corrosion resistance,and the wettability and fluidity during brazing.The formability and processability of brazing filler metals include the processes of smelting and casting,extrusion,rolling,drawing and ring-making,as well as the processes of granulation,powder production,and the molding of amorphous and microcrystalline structures.The cost of brazing filler metals corresponds to the sum of materials value and manufacturing cost.Improving the comprehensive properties of brazing filler metals requires a comprehensive and systematic consideration of design indicators.Highlighting the unique characteristics of brazing filler metals should focus on relevant technical indicators.Binary or ternary eutectic structures can effectively enhance the flow spreading ability of brazing filler metals,and solid solution structures contribute to the formability.By employing the proposed design guidelines,typical Ag based,Cu based,Zn based brazing filler metals,and Sn based solders were designed and successfully applied in major scientific and engineering projects.展开更多
基金Supported by the National Key Research and Development Program of Traditional Chinese Medicine Modernization Project,China(No.2023YFC3504000)the Science and Technology Development Project of Jilin Province,China(No.20240404043ZP)the Science and Technology Innovation Cooperation Project of Changchun Science and Technology Bureau and Chinese Academy of Sciences,China(No.23SH14)。
文摘In this study,a novel polysaccharide GPA-G 2-H was derived from ginseng.Furthermore,the coherent study of its structural characteristics,fermented characteristics in vitro,as well as antioxidant mechanism of fermented product FGPA-G 2-H on Aβ25-35-induced PC 12 cells were explored.The structure of GPA-G 2-H was determined by means of zeta potential analysis,FTIR,HPLC,XRD,GC-MS and NMR.The backbone of GPA-G 2-H was mainly composed of→4)-α-D-Glcp-(1→with branches substituted at O-3.Notably,GPA-G 2-H was degraded by intestinal microbiota in vitro with total sugar content and pH value decreasing,and short-chain fatty acids(SCFAs)increasing.Moreover,GPA-G 2-H significantly promoted the proliferation of Lactobacillus,Muribaculaceae and Weissella,thereby making positive alterations in intestinal microbiota composition.Additionally,FGPA-G 2-H activated the Nrf 2/HO-1 signaling pathway,enhanced HO-1,NQO 1,SOD and GSH-Px,while inhabited Keap 1,MDA and LDH,which alleviated Aβ-induced oxidative stress in PC 12 cells.These provide a solid theoretical basis for the further development of ginseng polysaccharides as functional food and antioxidant drugs.
基金Supported by the Science and Technology Cooperation and Exchange special project of Cooperation of Shanxi Province(202404041101014)the Fundamental Research Program of Shanxi Province(202403021212333)+3 种基金the Joint Funds of the National Natural Science Foundation of China(U24A20555)the Lvliang Key R&D of University-Local Cooperation(2023XDHZ10)the Initiation Fund for Doctoral Research of Taiyuan University of Science and Technology(20242026)the Outstanding Doctor Funding Award of Shanxi Province(20242080).
文摘To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content in coal)catalysts were prepared by the incipient wetness impregnation method,followed by acid washing to remove calcium-containing minerals.Comprehensive characterization and low-temperature denitrification tests revealed that calcite-induced structural modulation of coal-derived AC significantly enhances catalytic activity.Specifically,NO conversion increased from 88.3%of Mn-Ce/De-AC to 91.7%of Mn-Ce/De-AC-1CaCO_(3)(210℃).The improved SCR denitrification activity results from the enhancement of physicochemical properties including higher Mn^(4+)content and Ce^(4+)/Ce^(3+)ratio,an abundance of chemisorbed oxygen and acidic sites,which could strengthen the SCR reaction pathways(richer NH_(3)activated species and bidentate nitrate active species).Therefore,NO removal is enhanced.
文摘To address the neglect of seismic performance in conventional double-girder bridge crane optimization,this paper introduces a time-history analysis-based seismic optimization methodology for crane structures.Using a 25-t nuclear power crane as a case study,a bridge frame finite element model is established and validated through static analysis,confirming its accurate representation of the physical entity’s mechanical behavior.Furthermore,with bridge mass reduction as the objective and structural strength,stiffness,stability,and seismic mechanical performance as constraints,an optimization model is developed employing the Whale Optimization Algorithm(WOA).
基金supported by the Science and Technology Major Program of Yunnan(No.202402AG0500103)the Industrial Innovation Talent Project of Yunnan(No.XDYC-CYCX-2023007)the National Key Research and Development Program of China(No.2023YFC3709100).
文摘Exogenous organic input impacts soil phosphorus transformation.Meanwhile,dissolved organic matter(DOM)is crucial for biogeochemical functions.Nevertheless,the interaction between the structural composition of DOM and phosphorus during the soil formation process of phosphogypsum(PG)remains unknown.This study explores the interaction between the structural composition of DOM and phosphorus in enhanced PG under the participation of fungal microorganisms through different application amounts of exogenous organic matter and culture time.Results show that application of exogenous organic matter led to varying degrees of increase in dissolved organic carbon(DOC)concentration and humification extent in the soil-like substrate.Additionally,the relative abundance of protein-like component C3 exhibited a trend of initial increase followed by decline over time.The contents of available phosphorus(AP),microbial biomass phosphorus(MBP),and active phosphorus pools(Active-P)in the soil-like substrate are all enhanced overall.Furthermore,a significant correlation exists between DOC and AP as well as MBP.This suggests that DOM is a crucial factor in enhancing the phosphorus availability of the soil-like substrate.The enrichment of known phosphate-solubilizing fungi in culturing favors the decomposition,activation and utilization of hard-to-mineralize phosphorus components in the soil-like substrate.These findings help understand DOM’s biogeochemical behavior and offer insights into PG utilization and the sustainable development of China’s phosphorus industry.
基金funded by the National Natural Science Foundation of China(No.42274066),the Second Qinghai-Xizang Plateau Scientific Expedition and Research Program(STEP)(No.2019Q ZKK0701).
文摘The Kumkol Basin,situated in the northern margin of the Qinghai-Xizang Plateau,provides a unique window into understanding the dynamic mechanisms driving the plateau’s northern expansion.However,its formation and tectonic evolution remain poorly understood due to limited geophysical data in this region.In this study,we computed cross-correlations for the TT components of station-pairs with high signal-to-noise ratios to extract Love wave waveforms and further performed Lovewave ambient noise tomography to image the upper crustal shear-wave velocity structure of the Kumkol basin down to 10 km depth.Our seismic velocity model reveals that the Kumkol Basin has a sedimentary thickness exceeding 8 km,with its center located near the Arka Mountain on the southern side.This suggests that the basin was likely formed as a foreland basin in response to the uplift of the Qiman Tagh Mountain to the north.Additionally,integrated with seismic reflection data,our seismic velocity model images a detachment fault at the basin basement depth.We inferred that the Kumkol Anticlinorium at the basin’s center have been produced by multiple thrust faults converging into this detachment fault at 8–10 km depth following the Early to Middle Miocene uplift of the Qiman Tagh Mountain.This structural configuration indicates pulsed basinward deformation since the late Miocene,likely reflecting a tectonic regime shift from extrusion to distributed shortening in the northern Qinghai-Xizang Plateau.Our findings provide a high-resolution velocity model of the Kumkol Basin,offering critical insights into its structural evolution and supporting future resource exploration in this underexplored region.
基金supported by the National Natural Science Foundation of China(No.52374247)the Joint Funds of the National Natural Science Foundation of China(No.U24B2042).
文摘In igneous-intruded coal seams,coal undergoes significant metamorphism,which critically alters its pore structure and oxygen consumption dynamics,thereby elevating its spontaneous combustion tendency.This study investigates the specific surface area,pore volume,structure complexity/connectivity,heterogeneity/local features of pore size distribution,and oxygen consumption dynamics of igneous metamorphic coal through N_(2)/CO_(2) isothermal adsorption tests and low-temperature oxidation experiments,and elucidates the influence mechanisms of pore structure evolution on oxygen consumption dynamics during low-temperature oxidation.With increasing metamorphic degree,igneous metamorphic coal exhibits a more pronounced reduction in specific surface area during oxidation,while the increase in structure complexity due to coal-oxygen reactions is suppressed.Thermally metamorphic coal demonstrates accelerated oxygen consumption,with oxidation amplifying the difference in reaction rates compared to raw coal.Key mechanisms include oxidation-induced reduction in mesopore complexity and micropore volume,decreased dominance of small-pore-volume apertures,and increased heterogeneity,collectively leading to a lower half-oxygen-consuming temperature and steeper oxygen consumption curves.Simultaneously,increased pore volume/complexity and reduced uniformity/connectivity act synergistically to enhance oxygen consumption capacity,highlighting the coupling between pore structure evolution and oxidation behavior in igneous metamorphic coal.This study provides theoretical insights into the pore-oxygen coupling mechanisms governing coal spontaneous combustion in igneous intrusion areas.
文摘A detailed understanding of seismicity originating from the Nanga Parbat syntaxis in the northwestern Himalaya is crucial for characterizing the active fault systems and associated neotectonic processes in the region.Continuous earthquake monitoring through local seismic stations enables high-precision results by constraining the velocity structure.In this study,seismogram data from 244 small-magnitude earthquakes are analyzed to delineate the crustal thickness and investigate the source mechanisms beneath the Nanga Parbat syntaxis.The results are achieved with the application of Coupled Hypocenter Velocity Inversion(CHVI)analysis and Time Domain Moment Tensor(TDMT)analysis.The velocity inversion suggests that the Moho discontinuity lies at 60 km depth with an average vP/vS ratio of 1.735±0.017.The minimum 1D velocity model obtained through velocity inversion with least RMS error is further utilized in determining the source mechanism solution.In contrast to earlier studies,which highlighted strike-slip displacement accompanied by reverse dip-slip components,the present research provides a revised interpretation.The moment tensor analysis conducted in this study provides evidence of transtensional deformation associated with neotectonics,attributed to the presence of multiple shear zones.The results of the source mechanism for the selected earthquakes unveiled that the oblique-slip deformation is significantly controlled by the shear stresses coupled with the normal component of dip-slip movement.This is further supported by the higher values of the doublecouple moment tensor(85%),which indicate shear deformation,while the positive value of the compensated linear vector dipole(15%)confirms the presence of a normal component.The coexistence of transpressive and transtensive stresses,together with shallow hypocentral depths and high-amplitude tangential waveforms,can potentially cause devastating impacts in the surroundings of the Nanga Parbat syntaxis.
文摘This study investigates the thermo–mechanical behavior of C40 concrete and reinforced concrete subjected to elevated temperatures up to 700℃by integrating experimental testing and advanced numerical modeling.A temperature-indexed Concrete Damage Plasticity(CDP)framework incorporating bond–slip effects was developed in Abaqus to capture both global stress–strain responses and localized damage evolution.Uniaxial compression tests on thermally exposed cylinders provided residual strength data and failure observations for model calibration and validation.Results demonstrated a distinct two-stage degradation regime:moderate stiffness and strength reduction up to~400℃,followed by sharp deterioration beyond 500℃–600℃,with residual capacity at 700℃reduced to~20%–25%of the ambient value.Strain–damage analyses revealed the formation of a peripheral tensile strain band,which thickened and propagated inward with increasing temperature,governing crack initiation and cover spalling.Supplemental analyses highlighted that transverse reinforcement improved ductility and damage distribution at moderate temperatures(~300℃),but bond deterioration and steel softening beyond~600℃substantially diminished confinement effectiveness.The proposed CDP model accurately reproduced experimental stress–strain curves(R^(2)≈0.94–0.98 up to 600℃;≈0.90 at 700℃),with peak stress errors within 7%–10%and energy absorption captured within~12%.These findings confirm the robustness of the temperature-indexed CDP framework for simulating fire-damaged reinforced concrete and provide practical guidelines for post-fire assessment,spalling detection,and fire-resilient design of structural members.
基金Project(2023AH051167)supported by the Natural Science Research Project of Anhui Educational Committee,ChinaProject(AHBP2024B-04)supported by the Foundation of Anhui Engineering Research Center of New Explosive Materials and Blasting Technology,China+1 种基金Project(GXZDSYS2023103)supported by the Open Fund for Anhui Key Laboratory of Mining Construction Engineering,ChinaProjects(52274071,52404155)supported by the National Natural Science Foundation of China。
文摘Aiming at the problem of dynamic instability of hard-brittle jointed rock surrounding in deep tunnel/roadway engineering,combining with the support concepts of"coupling rigidity with flexibility"and"overcoming rigidity by flexibility",the prevention and control method with"rigid-flexible coupling(R-F-C)"was put forward.Through numerical simulation calculation,the impact damage process,acoustic emission(AE)evolution characteristics,and element stress/displacement evolution characteristics of unsupported surrounding rock structure model,rigid supporting surrounding rock structure model,and"R-F-C"supporting surrounding rock structure model under horizontal bidirectional impact loading were compared and analyzed.Based on the theory of stress wave propagation,the dynamic instability catastrophe mechanism of three kinds of supporting structure models induced by horizontal bidirectional impact loading was revealed.Based on the Mohr-Coulomb strength theory,the stress discrimination methods of dynamic catastrophe of surrounding rock induced by horizontal bidirectional impact loading under three kinds of supporting structures were proposed.Combined with the above numerical simulation study,the explosion impact physical and mechanical test of"R-F-C"surrounding rock supporting plate structure was further designed and carried out.Finally,combined with the"conceptual model of ball-cliff potential energy instability",the energy driving theory and energy transformation mechanism of impact-induced rockburst under three kinds of supporting structures were discussed deeply.The research results provided a scientific basis for further promoting the effective application of"R-F-C"supporting structure in the prevention and control of dynamic instability of deep tunnel/roadway surrounding rock.
基金supported by grants from the Beijing Xisike Clinical Oncology Research Foundation(No.Y-Young2024-0138)China Postdoctoral Science Foundation(No.2024M750538)Qingdao Chengyang People’s Hospital Fund Project(No.202510300).
文摘Background:Tertiary lymphoid structures(TLSs)promote antitumor immunity and predict favorable immunotherapy outcomes in breast cancer.The study aimed to investigate how Tryptophan 2,3-dioxygenase(TDO2)-associated tryptophan metabolism influences TLS maturation and B cell class switching in breast cancer.Methods:Bulk transcriptomic data from The Cancer Genome Atlas-Breast Invasive Carcinoma(TCGA-BRCA,n=1055)were analyzed using Gene Set Variation Analysis(GSVA)-based metabolic scoring,immune deconvolution,and TLS quantification.Single-cell RNA sequencing(scRNA-seq,n=26)and spatial transcriptomics(n=1)were applied to map TDO2 expression and TLS spatial organization.Validation was performed by immunohistochemistry(n=38)and multiplex immunofluorescence(n=12).Results:We identified that elevated tryptophan metabolism was predominantly enriched in the Luminal A subtype and delineates an immune-cold phenotype with less immunogenicity,associated with a distinct immune-dominant cellular microenvironment,particularly enriched in T and plasma cells.High expression of the tryptophan-metabolizing enzyme TDO2 was significantly enriched in TLS-low tumors and negatively correlated with TLS maturation signatures.Functional enrichment revealed suppressed B cell class switching and attenuated C-X-C motif chemokine ligand 9(CXCL9)expression in TLS-deficient tumors.Spatial transcriptomics and hotspot analysis demonstrated an inverse spatial correlation between TDO2 expression and TLS core components.Tumors with high tryptophan metabolism showed decreased cluster of differentiation 20(CD20)^(+)and CXCL9^(+)cell infiltration within TLS zones.Tumors with strong TDO2-kynurenine activity displayed impaired TLS organization and attenuated humoral immunity.Conditional spatial co-occurrence modeling confirmed reduced proximity between tryptophan metabolism hotspots and TLS-related immune features.Conclusion:In conclusion,our findings suggest that TDO2-associated tryptophan metabolism is linked to impaired TLS maturation and suppressed B cell class switching in breast cancer.Targeting the TDO2-kynurenine axis may represent a promising strategy to restore TLS formation and enhance immunotherapy responsiveness in breast cancer.
基金National Natural Science Foundation of China(U22A20191)。
文摘Brazing filler metals are widely applied,which serve as an industrial adhesive in the joining of dissimilar structures.With the continuous emergence of new structures and materials,the demand for novel brazing filler metals is ever-increasing.It is of great significance to investigate the optimized composition design methods and to establish systematic design guidelines for brazing filler metals.This study elucidated the fundamental rules for the composition design of brazing filler metals from a three-dimensional perspective encompassing the basic properties of applied brazing filler metals,formability and processability,and overall cost.The basic properties of brazing filler metals refer to their mechanical properties,physicochemical properties,electromagnetic properties,corrosion resistance,and the wettability and fluidity during brazing.The formability and processability of brazing filler metals include the processes of smelting and casting,extrusion,rolling,drawing and ring-making,as well as the processes of granulation,powder production,and the molding of amorphous and microcrystalline structures.The cost of brazing filler metals corresponds to the sum of materials value and manufacturing cost.Improving the comprehensive properties of brazing filler metals requires a comprehensive and systematic consideration of design indicators.Highlighting the unique characteristics of brazing filler metals should focus on relevant technical indicators.Binary or ternary eutectic structures can effectively enhance the flow spreading ability of brazing filler metals,and solid solution structures contribute to the formability.By employing the proposed design guidelines,typical Ag based,Cu based,Zn based brazing filler metals,and Sn based solders were designed and successfully applied in major scientific and engineering projects.
