This paper focuses on the use of rotary-percussive drilling for hard rocks.In order to improve efficiency and reduce costs,it is essential to understand how operational parameters,bit wear,and drilling performance are...This paper focuses on the use of rotary-percussive drilling for hard rocks.In order to improve efficiency and reduce costs,it is essential to understand how operational parameters,bit wear,and drilling performance are related.A model is presented therein that combines multibody dynamics and discrete element method(DEM)to investigate the influences of operational parameters and bit wear on the rate of penetration and wear characteristics.The model accurately captures the motion of the bit and recreates rock using the cutting sieving result.Field experimental results validate the rod dynamic behavior,rock recreating model,and coupling model in the simulation.The findings indicate that hammer pressure significantly influences the rate of penetration and wear depth of the bit,and there is an optimal range for economical hammer pressure.The wear coefficient has a major effect on the rate of penetration,when wear coefficient is between 1/3 and 2/3.Increasing the wear coefficient can reduce drill bit button pressure and wear depth at the same drill distance.Gauge button loss increases the rate of penetration due to higher pressure on the remaining buttons,which also accelerates destruction of the bit.Furthermore,a more evenly distributed button on the bit enhances the rate of penetration(ROP)when the same number of buttons is lost.展开更多
Hierarchical lignin-derived ordered mesoporous carbon(HOMC)was significant for advanced supercapacitors.However,achieving controllable fabrication and optimizing electrochemical behavior were challenging.In this work,...Hierarchical lignin-derived ordered mesoporous carbon(HOMC)was significant for advanced supercapacitors.However,achieving controllable fabrication and optimizing electrochemical behavior were challenging.In this work,an eco-friendly HOMC was synthesized using lignin as carbon precursors and Zn^(2+)as cross-linking and pore-forming agents,followed by KHCO_(3)activation,eliminating the need for toxic phenolic resins and acid treatments for metal removal.Machine learning technology,specifically an Artificial Neural Network(ANN model,was utilized to assist the experimental design and prediction.The ANN model suggested an ideal hierarchical structure and optimized oxygen level,achieved through the adjustment of Zn^(2+)additive concentration,carbonization temperature,and subsequent KHCO_(3)activation to maximize capacitance.The HOMC electrode,with a micropore-to-mesopore ratio(S_(micro)/S_(meso))of 1.01 and an oxygen content of 8.81 at%,acquired a specific capacitance of 362 F·g^(-1)at 0.5 A·g^(-1)in 6 mol·L^(-1)KOH electrolyte.The assembled HOMC//HOMC supercapacitor could afford a high energy density of 33.38 Wh·kg^(-1)with a corresponding specific power density of 300 W·kg^(-1)in TEATFB PC electrolyte.Meanwhile,the long-term cycle stability of 94.33%was achieved after 20,000 cycles.This work provides an ANN assisted strategy for the synthesis of HOMC,highlighting its potential to valorize biomass and agricultural waste in sustainable energy storag solutions.展开更多
Thermal damage mechanisms are crucial in reservoir stimulation for enhanced geothermal system(EGS).This study investigates the thermal damage mechanisms in granite samples from the Gonghe Basin,Qinghai,China.The grani...Thermal damage mechanisms are crucial in reservoir stimulation for enhanced geothermal system(EGS).This study investigates the thermal damage mechanisms in granite samples from the Gonghe Basin,Qinghai,China.The granite samples were heated to 400℃ and then cooled in air,water,or liquid nitrogen.The physical and mechanical properties of the thermally treated granite were evaluated,andmicrostructural changes were analyzed using a scanning electron microscope(SEM)and computed tomography(CT).The results indicate that cooling with water and liquid nitrogen significantly enhancespermeability and brittleness while reducing P-wave velocity,strength,and Young's modulus.Specifically,liquid nitrogen cooling increased granite permeability by a factor of 5.24 compared to the untreatedsamples,while reducing compressive strength by 13.6%.After thermal treatment,the failure mode of thegranite shifted from axial splitting to a combination of shear and tension.Microstructural analysisrevealed that liquid nitrogen-cooled samples exhibited greater fracture complexity than those cooledwith water or air.Additionally,acoustic emission(AE)monitoring during damage evolution showed thatliquid nitrogen cooling led to higher cumulative AE energy and a lower maximum AE energy rate,withnumerous AE signals detected during both stable and unstable crack growth.The results suggest thatliquid nitrogen induces a stronger thermal shock,leading to more significant thermal damage andpromoting the development of a complex fracture network during EGS reservoir stimulation.This enhancesboth the heat exchange area and the permeability of the deep hot dry rock(HDR)in EGS reservoirs.The insights from this study contribute to a deeper understanding of thermal damagecharacteristics induced by different cooling media and provide valuable guidance for optimizing deepgeothermal energy extraction.展开更多
Intraspecific genetic variance and gene flow can support the adaptive evolution of species challenged by climate shifts or novel environmental conditions.Less well understood is how genome organization and gene flow i...Intraspecific genetic variance and gene flow can support the adaptive evolution of species challenged by climate shifts or novel environmental conditions.Less well understood is how genome organization and gene flow interact in closely related species during evolutionary divergence and differentiation.Here we conducted genomic footprint analyses to determine how three species of Pterocarya(P.stenoptera,P.hupehensis,and P.macroptera),which are sympatric but occupy different elevational niches,adapted to the heterogeneous environment of the Qinling-Daba Mountains,China.We identified candidate genes for environmental adaptation(i.e.,PIEZO1,WRKY39,VDAC3,CBL1,and RAF),and also identified regions of gene introgression between P.hupehensis and P.macroptera that show lower genetic load and higher genetic diversity than the rest of their genomes.The same introgressed regions are notably situated in areas of minimal genetic divergence yet they are characterized by elevated recombination rates.We also identified candidate genes within these introgressed regions related to environmental adaptation(TPLC2,CYCH;1,LUH,bHLH112,GLX1,TLP-3,and ABC1).Our findings have thus clarified the important role of gene flow in ecological adaptation and revealed genomic signatures of past introgression.Together,these findings provide a stronger theoretical basis for understanding the ecological adaptation and conservation of Quaternary relict woody plants in East Asia.展开更多
Biocompatible amphiphilic nanoparticles(NPs)with tunable particle morphology and surface property are important for their applications as functional materials.However,previously developed methods to prepare amphiphili...Biocompatible amphiphilic nanoparticles(NPs)with tunable particle morphology and surface property are important for their applications as functional materials.However,previously developed methods to prepare amphiphilic NPs generally involve several steps,especially an additional step for surface modification,greatly hindering their largescale production and widespread applications.Here,a versatile one-step strategy is developed to prepare biocompatible amphiphilic dimer NPs with tunable particle morphology and surface property.The amphiphilic dimer NPs,which consist of a hydrophobic shellac bulb and a hydrophilic poly(lactic acid)(PLA)bulb with PLA-poly(ethylene glycol)(PEG)on the bulb surface,are prepared in a single step by controlled co-precipitation and self-assembly.Amphiphilic PLA-PEG/shellac dimer NPs demonstrate excellent tunability in particle morphology,thus showing good performances in controlling the interfacial curvature and emulsion type.In addition,temperatureresponsive PLA-poly(N-isopropyl acrylamide)(PNIPAM)/shellac dimer NPs are prepared following the same method and emulsions stabilized by them show temperature-triggered response.The applications of PLA-PEG-folic acid(FA)/shellac dimer NPs for drug delivery have also been demonstrated,which show a very good performance.The strategy of preparing the dimer NPs is green,scalable,facile and versatile,which provides a good platform for the design of dimer NPs with tunable particle morphology and surface property for diverse applications.展开更多
China's shale oil and gas resources are widely distributed in shale-sandstone interbedded reservoirs,whose complex lithology and strong heterogeneity pose significant challenges to hydraulic fracturing design.To a...China's shale oil and gas resources are widely distributed in shale-sandstone interbedded reservoirs,whose complex lithology and strong heterogeneity pose significant challenges to hydraulic fracturing design.To address issues such as the difficulty in controlling fracture height and the challenge of forming an effective fracture network,this study utilizes synthetic rock samples that can represent the characteristics of interbedded reservoirs and investigates the initiation and propagation of hydraulic fractures under different viscosity,injection rate,and construction scheme.By combining real-time monitoring of injection pressure with acoustic emission,the temporal and spatial evolution characteristics of hydraulic fractures as well as the mechanisms of their vertical and horizontal extension are revealed.The results indicate that a higher fracturing fluid viscosity is essential for ensuring the vertical cross-layer propagation of hydraulic fractures,while a lower fluid viscosity facilitates the activation of weak interlayer surfaces,promoting sufficient horizontal propagation along these planes and forming branched fractures.Although a higher injection rate enhances the vertical cross-layer propagation of hydraulic fractures,it also causes greater diversion of the main fracture plane,resulting in simpler fracture morphology and limiting the stimulation effect.Additionally,an alternating injection of high and low viscosity fracturing fluids allows hydraulic fractures to both break through weak interlayer surfaces and achieve uniform horizontal propagation,resulting in a more complex fracture morphology.The findings are expected to provide a scientific basis and practical guidance for optimizing hydraulic fracturing designs in interbedded reservoir conditions.展开更多
Aerosol category and its physicochemical properties are key factors influencing its climate and environmental effects.To further enhance our understanding of aerosols in the Himalayas-Tibetan Plateau region,atmospheri...Aerosol category and its physicochemical properties are key factors influencing its climate and environmental effects.To further enhance our understanding of aerosols in the Himalayas-Tibetan Plateau region,atmospheric particulate matter samples were collected at three different altitudes on Mount Qomolangma(Everest).Using an automated scanning electron microscope system,the composition,size,and morphology of 52,349 particles were analyzed.The average mass concentrations of PM_(1),PM_(2.5),and PM_(10)were 0.678,5.054,and 16.698μg/m^(3),respectively.Aluminosilicate particles dominated the samples,accounting for 71.5%to 82.8%of PM_(10)mass and 34.7%to 62.4%of the particle number.Quartz particles,carbonate particles,metal oxides,and sulfates were also observed at different periods.Carbonaceous particles made up a significant portion of aerosols,comprising 2.1%to 9.7%of PM_(10)mass and 10.4%to 45.4%of particle number,with their concentration showing an upward trend with altitude.Small amounts of tar ball particles and fly ash particles were also observed,providing direct evidence of anthropogenic influences on high-altitude regions,even at altitudes exceeding 6000 m.The size distribution and abundance of different particle categories were closely related to the transport trajectories of air masses.The morphology of different particle categories varied,with fly ash particles mainly spherical and carbonaceous particles exhibiting higher irregularity.展开更多
In this study,a high-confining pressure and real-time large-displacement shearing-flow setup was developed.The test setup can be used to analyze the injection pressure conditions that increase the hydro-shearing perme...In this study,a high-confining pressure and real-time large-displacement shearing-flow setup was developed.The test setup can be used to analyze the injection pressure conditions that increase the hydro-shearing permeability and injection-induced seismicity during hot dry rock geothermal extraction.For optimizing injection strategies and improving engineering safety,real-time permeability,deformation,and energy release characteristics of fractured granite samples driven by injected water pressure under different critical sliding conditions were evaluated.The results indicated that:(1)A low injection water pressure induced intermittent small-deformation stick-slip behavior in fractures,and a high injection pressure primarily caused continuous high-speed large-deformation sliding in fractures.The optimal injection water pressure range was defined for enhancing hydraulic shear permeability and preventing large injection-induced earthquakes.(2)Under the same experimental conditions,fracture sliding was deemed as the major factor that enhanced the hydraulic shear-permeability enhancement and the maximum permeability increased by 36.54 and 41.59 times,respectively,in above two slip modes.(3)Based on the real-time transient evolution of water pressure during fracture sliding,the variation coefficients of slip rate,permeability,and water pressure were fitted,and the results were different from those measured under quasi-static conditions.(4)The maximum and minimum shear strength criteria for injection-induced fracture sliding were also determined(μ=0.6665 andμ=0.1645,respectively,μis friction coefficient).Using the 3D(three-dimensional)fracture surface scanning technology,the weakening effect of injection pressure on fracture surface damage characteristics was determined,which provided evidence for the geological markers of fault sliding mode and sliding nature transitions under the fluid influence.展开更多
Oxaliplatin(OXA)can be used as a palliative treatment for advanced hepatocellular carcinoma(HCC).While most patients still have rapid disease progression after OXA due to the drug resistance.The lactate dehydrogenase ...Oxaliplatin(OXA)can be used as a palliative treatment for advanced hepatocellular carcinoma(HCC).While most patients still have rapid disease progression after OXA due to the drug resistance.The lactate dehydrogenase A(LDHA)inhibitors can reduce the inflammation-induced effects,metastasis,and proliferation potential of cancer cells.Here,we adopt the water-in-oil attractive Pickering emulsion gel(APEG)to deliver OXA and LDHA inhibitor,GSK2837808A(GSK).OXA is dissolved in water and GSK is dissolved in iodized oil.This drugs-loaded APEG has good biocompatibility and can release OXA and GSK slowly.OXA+GSK@gel has significant anti-tumor effect on HCC model,which can effectively inhibit tumor cell proliferation and promote tumor cell apoptosis.Meanwhile,flow analysis confirm that it could activate the tumor immune microenvironment in HCC.The infiltration of CD8^(+)T cells is increased,thereby providing better anti-tumor effect.The results suggest that the APEGs loaded with OXA and GSK can effectively improve the delivery efficiency and enhance the anti-tumor therapy.展开更多
Objective This study was aimed to explore the prolonged therapeutic profile and underlying mechanisms of Yiqi Zishen Formula(YZF)in chronic obstructive pulmonary disease(COPD)management.Methods A COPD rat model was es...Objective This study was aimed to explore the prolonged therapeutic profile and underlying mechanisms of Yiqi Zishen Formula(YZF)in chronic obstructive pulmonary disease(COPD)management.Methods A COPD rat model was established through exposure to tobacco smoke and Klebsiella pneumoniae infections from weeks 1 to 8,followed by treatment with YZF from weeks 9 to 20.No treatment was administered from weeks 21 to 31.At week 32,all rats were euthanized,and lung tissue samples and blood specimens were collected for subsequent analyses.Then,comprehensive multiomics profiling—encompassing transcriptomics,proteomics,andmetabolomics—was conducted to identify differentially expressed molecules in lung tissues and elucidate the underlying molecular mechanisms.Results By week 32,sustained therapeutic efficacy became apparent,characterized by diminished inflammatory cytokine expression,mitigation of protease–antiprotease dysregulation,and reduced collagen deposition.These differentially expressed molecules were predominantly enriched in pathways related to oxidoreductase activity,antioxidant homeostasis,focal adhesion,tight junction formation,adherens junction dynamics,and lipid metabolism regulation.Integrative analysis of predicted targets,transcriptomic,proteomic,and metabolomic datasets revealed that differentially expressed molecules in YZF-treated rats and YZF-targeted proteins collectively participated in lipid metabolism,inflammatory responses,oxidative stress,and focal adhesion pathways.Conclusion YZF provides sustained therapeutic benefits in COPD rat models,potentially through systemic regulation of lipid metabolism,inflammatory responses,oxidative stress,and focal adhesion pathways.展开更多
A minority carrier lifetime of 25.46 μs in a P-type 4H-SiC epilayer has been attained through sequential thermal oxidation and hydrogen annealing. Thermal oxidation can enhance the minority carrier lifetime in the 4H...A minority carrier lifetime of 25.46 μs in a P-type 4H-SiC epilayer has been attained through sequential thermal oxidation and hydrogen annealing. Thermal oxidation can enhance the minority carrier lifetime in the 4H-SiC epilayer by reducing carbon vacancies. However, this process also generates carbon clusters with limited diffusivity and contributes to the enlargement of surface pits on the 4H-SiC. High-temperature hydrogen annealing effectively reduces stacking fault and dislocation density. Moreover, electron spin resonance analysis indicates a significant reduction in carbon vacancy defects after hydrogen annealing. The mechanisms of the elimination of carbon vacancies by hydrogen annealing include the decomposition of carbon clusters formed during thermal oxidation and the low-pressure selective etching by hydrogen,which increases the carbon content on the 4H-SiC surface and facilitates carbon diffusion. Consequently, the combination of thermal oxidation and hydrogen annealing eliminates carbon vacancies more effectively, substantially enhancing the minority carrier lifetime in P-type 4H-SiC. This improvement is advantageous for the application of high-voltage SiC bipolar devices.展开更多
This article presents an interpretation of the seismic source mechanisms for 905 earthquakes with MS>2.0,occurring in the central and southern sections of the Tan-Lu Fault Zone and its adjacent areas from 1970 to 2...This article presents an interpretation of the seismic source mechanisms for 905 earthquakes with MS>2.0,occurring in the central and southern sections of the Tan-Lu Fault Zone and its adjacent areas from 1970 to 2023.Utilizing the damped stress tensor method,we have inverted the spatial characteristics of the stress field variations in this study area,at a resolution of 1.0°×1.0°.The results indicate that the maximum principal stress direction within the central and southern sections of the Tan-Lu Fault Zone exhibits a spatially continuous change,rotating counterclockwise from East-West(EW)to Northeast-East(NEE),albeit with local variations.When dividing along the Tan-Lu Fault Zone,it is observed that on its western side—the North China block—a near EW stress field predominates.In contrast,on its eastern side—the Ludong-Huanghai Block—stress fields primarily exhibit NEE and Northeast-East(NE)orientations,underscoring the role of the Tan-Lu Fault Zone as a significant boundary between tectonic blocks.In regions located between latitudes 30°-34°N and longitudes 113°-115°E on the western side of these fault zone sections,maximum principal stress follows a radial distribution pattern indicative of a complex stress field.Conversely,on the eastern side of this fault zone,maximum principal stress direction remains relatively consistent,primarily displaying NEE and NE distributions.This reflects the fact that this area is situated under a tectonic background characterized by near NEE-NE direction for the Ludong-Huanghai Block.However,within an area bounded by latitudes 30°-32°N and longitudes 120°-122°E on the eastern flank of the Tan-Lu Fault Zone,maximum principal stress direction appears more intricate,with radial distribution patterns suggesting influences not only from near EW-NEE movements associated with the North China Block,but also from westward subduction processes related to Philippine Sea plate dynamics.Through our analysis of historical earthquakes in this region,we conclude that the moderate to strong seismic activity within this area is significantly related to the tectonic stress environment,with regions of complex tectonic stress often being the most seismically active.展开更多
基金supported by the National Natural Science Foundation of China Youth Science Foundation of China(Grant No.52308388)the Key Project of High-speed Rail Joint Fund of National Natural Science Foundation of China(Grant No.U1934210).
文摘This paper focuses on the use of rotary-percussive drilling for hard rocks.In order to improve efficiency and reduce costs,it is essential to understand how operational parameters,bit wear,and drilling performance are related.A model is presented therein that combines multibody dynamics and discrete element method(DEM)to investigate the influences of operational parameters and bit wear on the rate of penetration and wear characteristics.The model accurately captures the motion of the bit and recreates rock using the cutting sieving result.Field experimental results validate the rod dynamic behavior,rock recreating model,and coupling model in the simulation.The findings indicate that hammer pressure significantly influences the rate of penetration and wear depth of the bit,and there is an optimal range for economical hammer pressure.The wear coefficient has a major effect on the rate of penetration,when wear coefficient is between 1/3 and 2/3.Increasing the wear coefficient can reduce drill bit button pressure and wear depth at the same drill distance.Gauge button loss increases the rate of penetration due to higher pressure on the remaining buttons,which also accelerates destruction of the bit.Furthermore,a more evenly distributed button on the bit enhances the rate of penetration(ROP)when the same number of buttons is lost.
基金supported by National Natural Science Foundation of China(52376104,52201158)Joint Funds of the National Natural Science Foundation of China(U20A20302)+3 种基金Innovative group projects in Hebei Province(E2021202006)the project of Science and Technology in the Universities of Hebei Province(JZX2023006)Natural Science Foundation of Hebei Province(C202202003)Hebei University of Technology Cross-disciplinary(XKJC-2024001)。
文摘Hierarchical lignin-derived ordered mesoporous carbon(HOMC)was significant for advanced supercapacitors.However,achieving controllable fabrication and optimizing electrochemical behavior were challenging.In this work,an eco-friendly HOMC was synthesized using lignin as carbon precursors and Zn^(2+)as cross-linking and pore-forming agents,followed by KHCO_(3)activation,eliminating the need for toxic phenolic resins and acid treatments for metal removal.Machine learning technology,specifically an Artificial Neural Network(ANN model,was utilized to assist the experimental design and prediction.The ANN model suggested an ideal hierarchical structure and optimized oxygen level,achieved through the adjustment of Zn^(2+)additive concentration,carbonization temperature,and subsequent KHCO_(3)activation to maximize capacitance.The HOMC electrode,with a micropore-to-mesopore ratio(S_(micro)/S_(meso))of 1.01 and an oxygen content of 8.81 at%,acquired a specific capacitance of 362 F·g^(-1)at 0.5 A·g^(-1)in 6 mol·L^(-1)KOH electrolyte.The assembled HOMC//HOMC supercapacitor could afford a high energy density of 33.38 Wh·kg^(-1)with a corresponding specific power density of 300 W·kg^(-1)in TEATFB PC electrolyte.Meanwhile,the long-term cycle stability of 94.33%was achieved after 20,000 cycles.This work provides an ANN assisted strategy for the synthesis of HOMC,highlighting its potential to valorize biomass and agricultural waste in sustainable energy storag solutions.
基金support from the National Natural Science Foundation of China(Grant Nos.52192622 and 52304003)the National Key Research and Development Program of China(Grant No.2023YFF0614102).
文摘Thermal damage mechanisms are crucial in reservoir stimulation for enhanced geothermal system(EGS).This study investigates the thermal damage mechanisms in granite samples from the Gonghe Basin,Qinghai,China.The granite samples were heated to 400℃ and then cooled in air,water,or liquid nitrogen.The physical and mechanical properties of the thermally treated granite were evaluated,andmicrostructural changes were analyzed using a scanning electron microscope(SEM)and computed tomography(CT).The results indicate that cooling with water and liquid nitrogen significantly enhancespermeability and brittleness while reducing P-wave velocity,strength,and Young's modulus.Specifically,liquid nitrogen cooling increased granite permeability by a factor of 5.24 compared to the untreatedsamples,while reducing compressive strength by 13.6%.After thermal treatment,the failure mode of thegranite shifted from axial splitting to a combination of shear and tension.Microstructural analysisrevealed that liquid nitrogen-cooled samples exhibited greater fracture complexity than those cooledwith water or air.Additionally,acoustic emission(AE)monitoring during damage evolution showed thatliquid nitrogen cooling led to higher cumulative AE energy and a lower maximum AE energy rate,withnumerous AE signals detected during both stable and unstable crack growth.The results suggest thatliquid nitrogen induces a stronger thermal shock,leading to more significant thermal damage andpromoting the development of a complex fracture network during EGS reservoir stimulation.This enhancesboth the heat exchange area and the permeability of the deep hot dry rock(HDR)in EGS reservoirs.The insights from this study contribute to a deeper understanding of thermal damagecharacteristics induced by different cooling media and provide valuable guidance for optimizing deepgeothermal energy extraction.
基金supported by the National Natural Science Foundation of China(32370386,32070372,and 32200295)Science Foundation for Distinguished Young Scholars of Shaanxi Province(2023-JC-JQ-22)+4 种基金Basic Research Project of Shaanxi Academy of Fundamental Science(22JHZ005)Shaanxi Key Research and Development Program(2024NC-YBXM-064)Science and Technology Program of Shaanxi Academy of Science(2023K-49,2023K-26,and 2019K-06)Shaanxi Forestry Science and Technology Innovation Key Project(SXLK2023-02-20)Qinling Hundred Talents Project of Shaanxi Academy of Science(Y23Z619F17).
文摘Intraspecific genetic variance and gene flow can support the adaptive evolution of species challenged by climate shifts or novel environmental conditions.Less well understood is how genome organization and gene flow interact in closely related species during evolutionary divergence and differentiation.Here we conducted genomic footprint analyses to determine how three species of Pterocarya(P.stenoptera,P.hupehensis,and P.macroptera),which are sympatric but occupy different elevational niches,adapted to the heterogeneous environment of the Qinling-Daba Mountains,China.We identified candidate genes for environmental adaptation(i.e.,PIEZO1,WRKY39,VDAC3,CBL1,and RAF),and also identified regions of gene introgression between P.hupehensis and P.macroptera that show lower genetic load and higher genetic diversity than the rest of their genomes.The same introgressed regions are notably situated in areas of minimal genetic divergence yet they are characterized by elevated recombination rates.We also identified candidate genes within these introgressed regions related to environmental adaptation(TPLC2,CYCH;1,LUH,bHLH112,GLX1,TLP-3,and ABC1).Our findings have thus clarified the important role of gene flow in ecological adaptation and revealed genomic signatures of past introgression.Together,these findings provide a stronger theoretical basis for understanding the ecological adaptation and conservation of Quaternary relict woody plants in East Asia.
基金supported by National Natural Science Foundation of China(No.22278352)National Key Research and Development Program of China(No.2021YFC3001100)+3 种基金Longyan City Science and Technology Plan Project(No.2020LYF17043)Longyan City Science and Technology Plan Project(No.2020LYF17042)ARC Discovery Project(No.DP200101238)and NHMRC Investigator Grant(No.APP2008698)supported by the Harvard Materials Research Science and Engineering Center(No.DMR2011754)。
文摘Biocompatible amphiphilic nanoparticles(NPs)with tunable particle morphology and surface property are important for their applications as functional materials.However,previously developed methods to prepare amphiphilic NPs generally involve several steps,especially an additional step for surface modification,greatly hindering their largescale production and widespread applications.Here,a versatile one-step strategy is developed to prepare biocompatible amphiphilic dimer NPs with tunable particle morphology and surface property.The amphiphilic dimer NPs,which consist of a hydrophobic shellac bulb and a hydrophilic poly(lactic acid)(PLA)bulb with PLA-poly(ethylene glycol)(PEG)on the bulb surface,are prepared in a single step by controlled co-precipitation and self-assembly.Amphiphilic PLA-PEG/shellac dimer NPs demonstrate excellent tunability in particle morphology,thus showing good performances in controlling the interfacial curvature and emulsion type.In addition,temperatureresponsive PLA-poly(N-isopropyl acrylamide)(PNIPAM)/shellac dimer NPs are prepared following the same method and emulsions stabilized by them show temperature-triggered response.The applications of PLA-PEG-folic acid(FA)/shellac dimer NPs for drug delivery have also been demonstrated,which show a very good performance.The strategy of preparing the dimer NPs is green,scalable,facile and versatile,which provides a good platform for the design of dimer NPs with tunable particle morphology and surface property for diverse applications.
基金supported by the National Key Research and Development Program of China(Grant Nos.2023YFF0614102 and 2023YFE0110900)the National Natural Science Foundation of China(Grant Nos.52374004,52204005,and 52304003)the Natural Science Foundation of Sichuan Province(Grant Nos.2024NSFSC0961 and 2023NSFSC0940).
文摘China's shale oil and gas resources are widely distributed in shale-sandstone interbedded reservoirs,whose complex lithology and strong heterogeneity pose significant challenges to hydraulic fracturing design.To address issues such as the difficulty in controlling fracture height and the challenge of forming an effective fracture network,this study utilizes synthetic rock samples that can represent the characteristics of interbedded reservoirs and investigates the initiation and propagation of hydraulic fractures under different viscosity,injection rate,and construction scheme.By combining real-time monitoring of injection pressure with acoustic emission,the temporal and spatial evolution characteristics of hydraulic fractures as well as the mechanisms of their vertical and horizontal extension are revealed.The results indicate that a higher fracturing fluid viscosity is essential for ensuring the vertical cross-layer propagation of hydraulic fractures,while a lower fluid viscosity facilitates the activation of weak interlayer surfaces,promoting sufficient horizontal propagation along these planes and forming branched fractures.Although a higher injection rate enhances the vertical cross-layer propagation of hydraulic fractures,it also causes greater diversion of the main fracture plane,resulting in simpler fracture morphology and limiting the stimulation effect.Additionally,an alternating injection of high and low viscosity fracturing fluids allows hydraulic fractures to both break through weak interlayer surfaces and achieve uniform horizontal propagation,resulting in a more complex fracture morphology.The findings are expected to provide a scientific basis and practical guidance for optimizing hydraulic fracturing designs in interbedded reservoir conditions.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(No.2019QZKK0106)the Basic Research Fund of CAMS(Nos.2023Z004 and 2023Z015).
文摘Aerosol category and its physicochemical properties are key factors influencing its climate and environmental effects.To further enhance our understanding of aerosols in the Himalayas-Tibetan Plateau region,atmospheric particulate matter samples were collected at three different altitudes on Mount Qomolangma(Everest).Using an automated scanning electron microscope system,the composition,size,and morphology of 52,349 particles were analyzed.The average mass concentrations of PM_(1),PM_(2.5),and PM_(10)were 0.678,5.054,and 16.698μg/m^(3),respectively.Aluminosilicate particles dominated the samples,accounting for 71.5%to 82.8%of PM_(10)mass and 34.7%to 62.4%of the particle number.Quartz particles,carbonate particles,metal oxides,and sulfates were also observed at different periods.Carbonaceous particles made up a significant portion of aerosols,comprising 2.1%to 9.7%of PM_(10)mass and 10.4%to 45.4%of particle number,with their concentration showing an upward trend with altitude.Small amounts of tar ball particles and fly ash particles were also observed,providing direct evidence of anthropogenic influences on high-altitude regions,even at altitudes exceeding 6000 m.The size distribution and abundance of different particle categories were closely related to the transport trajectories of air masses.The morphology of different particle categories varied,with fly ash particles mainly spherical and carbonaceous particles exhibiting higher irregularity.
基金supported by the National Natural Science Foundation of China (Grant No.52122405)Science and Technology Major Project of Shanxi Province,China (Grant No.202101060301024)Science and Technology Major Project of Xizang Autonomous Region,China (Grant No.XZ202201ZD0004G0204).
文摘In this study,a high-confining pressure and real-time large-displacement shearing-flow setup was developed.The test setup can be used to analyze the injection pressure conditions that increase the hydro-shearing permeability and injection-induced seismicity during hot dry rock geothermal extraction.For optimizing injection strategies and improving engineering safety,real-time permeability,deformation,and energy release characteristics of fractured granite samples driven by injected water pressure under different critical sliding conditions were evaluated.The results indicated that:(1)A low injection water pressure induced intermittent small-deformation stick-slip behavior in fractures,and a high injection pressure primarily caused continuous high-speed large-deformation sliding in fractures.The optimal injection water pressure range was defined for enhancing hydraulic shear permeability and preventing large injection-induced earthquakes.(2)Under the same experimental conditions,fracture sliding was deemed as the major factor that enhanced the hydraulic shear-permeability enhancement and the maximum permeability increased by 36.54 and 41.59 times,respectively,in above two slip modes.(3)Based on the real-time transient evolution of water pressure during fracture sliding,the variation coefficients of slip rate,permeability,and water pressure were fitted,and the results were different from those measured under quasi-static conditions.(4)The maximum and minimum shear strength criteria for injection-induced fracture sliding were also determined(μ=0.6665 andμ=0.1645,respectively,μis friction coefficient).Using the 3D(three-dimensional)fracture surface scanning technology,the weakening effect of injection pressure on fracture surface damage characteristics was determined,which provided evidence for the geological markers of fault sliding mode and sliding nature transitions under the fluid influence.
基金supported by Natural Science Foundation of Zhejiang Province(Nos.LY20H160033,LY22H160019)National Key Research and Development Program of China(No.YS2021YFC3000089)+1 种基金Zhejiang Province Science and Technology Plan Project(No.2024C03175)National Natural Science Foundation of China(Nos.82074208,22278352,82473004).
文摘Oxaliplatin(OXA)can be used as a palliative treatment for advanced hepatocellular carcinoma(HCC).While most patients still have rapid disease progression after OXA due to the drug resistance.The lactate dehydrogenase A(LDHA)inhibitors can reduce the inflammation-induced effects,metastasis,and proliferation potential of cancer cells.Here,we adopt the water-in-oil attractive Pickering emulsion gel(APEG)to deliver OXA and LDHA inhibitor,GSK2837808A(GSK).OXA is dissolved in water and GSK is dissolved in iodized oil.This drugs-loaded APEG has good biocompatibility and can release OXA and GSK slowly.OXA+GSK@gel has significant anti-tumor effect on HCC model,which can effectively inhibit tumor cell proliferation and promote tumor cell apoptosis.Meanwhile,flow analysis confirm that it could activate the tumor immune microenvironment in HCC.The infiltration of CD8^(+)T cells is increased,thereby providing better anti-tumor effect.The results suggest that the APEGs loaded with OXA and GSK can effectively improve the delivery efficiency and enhance the anti-tumor therapy.
基金supported by the National Natural Science Fund of China(81130062).
文摘Objective This study was aimed to explore the prolonged therapeutic profile and underlying mechanisms of Yiqi Zishen Formula(YZF)in chronic obstructive pulmonary disease(COPD)management.Methods A COPD rat model was established through exposure to tobacco smoke and Klebsiella pneumoniae infections from weeks 1 to 8,followed by treatment with YZF from weeks 9 to 20.No treatment was administered from weeks 21 to 31.At week 32,all rats were euthanized,and lung tissue samples and blood specimens were collected for subsequent analyses.Then,comprehensive multiomics profiling—encompassing transcriptomics,proteomics,andmetabolomics—was conducted to identify differentially expressed molecules in lung tissues and elucidate the underlying molecular mechanisms.Results By week 32,sustained therapeutic efficacy became apparent,characterized by diminished inflammatory cytokine expression,mitigation of protease–antiprotease dysregulation,and reduced collagen deposition.These differentially expressed molecules were predominantly enriched in pathways related to oxidoreductase activity,antioxidant homeostasis,focal adhesion,tight junction formation,adherens junction dynamics,and lipid metabolism regulation.Integrative analysis of predicted targets,transcriptomic,proteomic,and metabolomic datasets revealed that differentially expressed molecules in YZF-treated rats and YZF-targeted proteins collectively participated in lipid metabolism,inflammatory responses,oxidative stress,and focal adhesion pathways.Conclusion YZF provides sustained therapeutic benefits in COPD rat models,potentially through systemic regulation of lipid metabolism,inflammatory responses,oxidative stress,and focal adhesion pathways.
基金Project supported by the National Key Research and Development Program of China (Grant Nos. 2023YFB3609500 and 2023YFB3609502)the National Natural Science Foundation of China (Grant No. 62274137)+1 种基金the Natural Science Foundation of Jiangxi Province, China (Grant No. 20232BAB202043)the Science and Technology Project of Fujian Province of China (Grant No. 2020I0001)。
文摘A minority carrier lifetime of 25.46 μs in a P-type 4H-SiC epilayer has been attained through sequential thermal oxidation and hydrogen annealing. Thermal oxidation can enhance the minority carrier lifetime in the 4H-SiC epilayer by reducing carbon vacancies. However, this process also generates carbon clusters with limited diffusivity and contributes to the enlargement of surface pits on the 4H-SiC. High-temperature hydrogen annealing effectively reduces stacking fault and dislocation density. Moreover, electron spin resonance analysis indicates a significant reduction in carbon vacancy defects after hydrogen annealing. The mechanisms of the elimination of carbon vacancies by hydrogen annealing include the decomposition of carbon clusters formed during thermal oxidation and the low-pressure selective etching by hydrogen,which increases the carbon content on the 4H-SiC surface and facilitates carbon diffusion. Consequently, the combination of thermal oxidation and hydrogen annealing eliminates carbon vacancies more effectively, substantially enhancing the minority carrier lifetime in P-type 4H-SiC. This improvement is advantageous for the application of high-voltage SiC bipolar devices.
基金supported by the National Natural Science Foundation of China(Grant Nos.41802224)Science for Earthquake Resilience of China Earthquake Administration(Grant Nos.XH23019YC and Nos.XH24021C)+2 种基金Joint Open Fund of Mengcheng National Geophysical Observatory(Grant Nos.MENGO-202306)Key R&D and Achievement Transformation Projects of the Science and Technology Program in Wuhu City,Anhui Province(2023yf007)Open Fund of Wuhan,Gravitation and Solid Earth Tides,National Observation and Research Station(Grant Nos.WHYWZ202209).
文摘This article presents an interpretation of the seismic source mechanisms for 905 earthquakes with MS>2.0,occurring in the central and southern sections of the Tan-Lu Fault Zone and its adjacent areas from 1970 to 2023.Utilizing the damped stress tensor method,we have inverted the spatial characteristics of the stress field variations in this study area,at a resolution of 1.0°×1.0°.The results indicate that the maximum principal stress direction within the central and southern sections of the Tan-Lu Fault Zone exhibits a spatially continuous change,rotating counterclockwise from East-West(EW)to Northeast-East(NEE),albeit with local variations.When dividing along the Tan-Lu Fault Zone,it is observed that on its western side—the North China block—a near EW stress field predominates.In contrast,on its eastern side—the Ludong-Huanghai Block—stress fields primarily exhibit NEE and Northeast-East(NE)orientations,underscoring the role of the Tan-Lu Fault Zone as a significant boundary between tectonic blocks.In regions located between latitudes 30°-34°N and longitudes 113°-115°E on the western side of these fault zone sections,maximum principal stress follows a radial distribution pattern indicative of a complex stress field.Conversely,on the eastern side of this fault zone,maximum principal stress direction remains relatively consistent,primarily displaying NEE and NE distributions.This reflects the fact that this area is situated under a tectonic background characterized by near NEE-NE direction for the Ludong-Huanghai Block.However,within an area bounded by latitudes 30°-32°N and longitudes 120°-122°E on the eastern flank of the Tan-Lu Fault Zone,maximum principal stress direction appears more intricate,with radial distribution patterns suggesting influences not only from near EW-NEE movements associated with the North China Block,but also from westward subduction processes related to Philippine Sea plate dynamics.Through our analysis of historical earthquakes in this region,we conclude that the moderate to strong seismic activity within this area is significantly related to the tectonic stress environment,with regions of complex tectonic stress often being the most seismically active.
