There is a prominent,complex and diverse three-dimensional climate and a variety of meteorological disasters in Qujing area. The risk zoning of low-temperature disasters for flue-cured tobacco planting in Qujing area ...There is a prominent,complex and diverse three-dimensional climate and a variety of meteorological disasters in Qujing area. The risk zoning of low-temperature disasters for flue-cured tobacco planting in Qujing area was studied to provide reference for drawing on advantages and avoiding disadvantages in flue-cured tobacco planting,disaster reduction,and disaster relief services. According to the production practice of fluecured tobacco and local climate analysis,it was determined that flue-cured tobacco in Qujing area was very vulnerable to low temperature during the seedling stage（ from early February to middle April） and in the mature period（ from early July to early September）. Based on the quantitative analysis and evaluation of risk of disaster-causing factors,sensitivity of disaster-breeding environment,vulnerability of carriers,and disaster prevention and reduction capability,a risk assessment model of meteorological disasters was established to precisely evaluate and zone the risk of low-temperature disasters for flue-cured tobacco planting in allusion to the seedling and mature stage in Qujing area by using GIS technology. The risk of lowtemperature disasters for flue-cured tobacco planting during the two periods was divided into four grades,namely low,medium,high and very high risk.展开更多
The modern world remains vulnerable to natural disasters,including floods,earthquakes,wildfires,and others.These events remain unpredictable and inevitable,and recovering quickly and effectively requires significant e...The modern world remains vulnerable to natural disasters,including floods,earthquakes,wildfires,and others.These events remain unpredictable and inevitable,and recovering quickly and effectively requires significant effort and expense.Monitoring is becoming more efficient thanks to technologies such as Unmanned Aerial Vehicles(UAVs),which can access hard-to-reach areas and provide real-time data.However,in disaster-affected areas,these monitoring systems may encounter many obstacles when communicating with servers or transmitting monitored data.This paper proposes an adaptive communication model to overcome the challenges faced in disaster-affected areas.A base station is responsible for collecting data(such as images and videos)captured by UAVs performing surveillance within its communication range.This station is typically a tower providing fixed cellular network service.However,in the absence of such a tower,a selected UAV may serve as the station,depending on the situation.If surveillance needs to be performed outside the coverage area,it can continue to communicate via nearby UAVs through cooperative communication.UAVs with internet support,known as the Internet of Flying Things(IoFT),will also be utilized to enhance communication capacity and efficiency.The proposed communication model is validated through experiments,showing superior data transmission performance and higher throughput.Analysis indicates it outperforms traditional systems,even in rural areas,with or without internet access.展开更多
In order to explore the effects of CaO,lignite dust and sawdust on the drying characteristics ofmunicipal sludge at different concentrations,a three-factor three-level regression experiment was carried out based on th...In order to explore the effects of CaO,lignite dust and sawdust on the drying characteristics ofmunicipal sludge at different concentrations,a three-factor three-level regression experiment was carried out based on the results of thermogravimetric experiment and single factor experiment.By fitting three common mathematical models,the Page model with the highest fitting degree was selected to determine the most suitable mathematical model to describe the municipal sludge drying process.In addition,the Box-Behnken design principle in the response surface method was used to analyze the interaction of three factors on the drying characteristics of municipal sludge.The results of the study show that below 100℃is the optimal drying temperature range for municipal sludge.The results of single factor experiments showed that the order of influence of the three factors on sludge drying time was CaO concentration>sawdust concentration>lignite dust concentration.In the single factor experiment,the optimal process parameterswere CaOconcentration 3%,lignite powder concentration 7%,and sawdust concentration 7%.In themulti-factor interaction analysis,the interaction between CaO and sawdust had the most significant effect on the reduction of drying time,and the order of influence was as follows:CaO interaction with sawdust>lignite dust interaction with sawdust>CaO interaction with lignite powder.Further analysis showed that the optimal process ratio was 3%CaO concentration and 3%sawdust concentration.展开更多
Lithium-ion batteries(LIBs),while dominant in energy storage due to high energy density and cycling stability,suffer from severe capacity decay,rate capability degradation,and lithium dendrite formation under low-temp...Lithium-ion batteries(LIBs),while dominant in energy storage due to high energy density and cycling stability,suffer from severe capacity decay,rate capability degradation,and lithium dendrite formation under low-temperature(LT)operation.Therefore,a more comprehensive and systematic understanding of LIB behavior at LT is urgently required.This review article comprehensively reviews recent advancements in electrolyte engineering strategies aimed at improving the low-temperature operational capabilities of LIBs.The study methodically examines critical performance-limiting mechanisms through fundamental analysis of four primary challenges:insufficient ionic conductivity under cryogenic conditions,kinetically hindered charge transfer processes,Li+transport limitations across the solidelectrolyte interphase(SEI),and uncontrolled lithium dendrite growth.The work elaborates on innovative optimization approaches encompassing lithium salt molecular design with tailored dissociation characteristics,solvent matrix optimization through dielectric constant and viscosity regulation,interfacial engineering additives for constructing low-impedance SEI layers,and gel-polymer composite electrolyte systems.Notably,particular emphasis is placed on emerging machine learning-guided electrolyte formulation strategies that enable high-throughput virtual screening of constituent combinations and prediction of structure-property relationships.These artificial intelligence-assisted rational design frameworks demonstrate significant potential for accelerating the development of next-generation LT electrolytes by establishing quantitative composition-performance correlations through advanced data-driven methodologies.展开更多
This study focused on improving the cathode performance of Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.15)O_(3-δ)(BSCN)-based perovskite materials through molybdenum(Mo)doping.Pure BSCN and Mo-modified-BSCN—Ea_(0.6)Sr_(0.4)Co_(0...This study focused on improving the cathode performance of Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.15)O_(3-δ)(BSCN)-based perovskite materials through molybdenum(Mo)doping.Pure BSCN and Mo-modified-BSCN—Ea_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.1)Mo_(0.05)O_(3-δ)(B S CNM_(0.05)),Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.05)Mo_(0.1)O_(3-δ)(BSCNM_(0.1)),and Ba_(0.6)Sr_(0.4)Co_(0.85)Mo_(0.15)O_(3-δ)(BSCM)—with Mo doping contents of 5mol%,10mol%,and15mol%,respectively,were successfully prepared using the sol-gel method.The effects of Mo doping on the crystal structure,conductivity,thermal expansion coefficient,oxygen reduction reaction(ORR)activity,and electrochemical performance were systematically evaluated using X-ray diffraction analysis,thermally induced characterization,electrochemical impedance spectroscopy,and single-cell performance tests.The results revealed that Mo doping could improve the conductivity of the materials,suppress their thermal expansion effects,and significantly improve the electrochemical performance.Surface chemical state analysis using X-ray photoelectron spectroscopy revealed that 5mol%Mo doping could facilitate a high adsorbed oxygen concentration leading to enhanced ORR activity in the materials.Density functional theory calculations confirmed that Mo doping promoted the ORR activity in the materials.At an operating temperature of 600℃,the BSCNM_(0.05)cathode material exhibited significantly enhanced electrochemical impedance characteristics,with a reduced area specific resistance of 0.048Ω·cm~2,which was lower than that of the undoped BSCN matrix material by 32.39%.At the same operating temperature,an anode-supported single cell using a BSCNM_(0.05)cathode achieved a peak power density of 1477 mW·cm^(-2),which was 30.71%,56.30%,and 171.50%higher than those of BSCN,BSCNM_(0.1),and B SCM,respectively.The improved ORR activity and electrochemical performance of BSCNM_(0.05)indicate that it can be used as a cathode material in low-temperature solid oxide fuel cells.展开更多
On December 18,2023,a magnitude 6.2 earthquake struck Jishishan County,Gansu Province,triggering a liquefaction-induced flow slide along the loess-mudstone contact zone and causing significant casualties and property ...On December 18,2023,a magnitude 6.2 earthquake struck Jishishan County,Gansu Province,triggering a liquefaction-induced flow slide along the loess-mudstone contact zone and causing significant casualties and property losses.The event featured low-slope,large-scale,runout distance sliding and exhibited a clear cascading disaster chain.Its characteristics closely resemble the catastrophic mudflow at the nearby Lajia Ruins approximately 4,000 years ago.Using high-resolution oblique photogrammetry,cone penetration testing,surface wave analysis,and horizontal-to-vertical spectral ratio methods,this study examines the stratigraphy,groundwater conditions,and geomechanical properties of the affected zone.Results indicate that saturated loess overlying impermeable mudstone formed a high-moisture mass vulnerable to seismic disturbance.Seismic resonance triggered the liquefaction of weakly structured loess,which slide along the contact interface and evolved into a runout distance mudflow.Underground water and terrain modification created a composite weak zone of saturated loess and softened mudstone,which intensified the disaster chain-from earthquake to liquefaction,flow slide,and mudflow.This study contributes to the understanding of deep-seated liquefaction-flow slide disasters,thereby advancing more effective risk mitigation strategies in the Loess Plateau and comparable loess-covered seismic regions.展开更多
Water-sand gushing(WSG)disasters in confinedaquifers pose significantchallenges to the utilization of deep underground spaces in soft soil areas.Since few studies have considered the impact of confined aquifer thickne...Water-sand gushing(WSG)disasters in confinedaquifers pose significantchallenges to the utilization of deep underground spaces in soft soil areas.Since few studies have considered the impact of confined aquifer thickness and confinedwater pressure on WSG disasters,a novel visual model test system was developed to investigate the influencingcharacteristics and mechanisms of the two aforementioned factors.The test results showed that the WSG process in clay aquiclude-confinedaquifer composite strata exhibits two prominent stages.First,the sand loss zone expands vertically in an ellipsoid shape.Then,it expands horizontally once the ellipsoid reaches the boundary of the clay layer.The sand loss continues until the overlying clay sinks to the bottom to clog the gushing crack,creating a large sinkhole at the surface.Increasing the confinedaquifer thickness can increase the vertical expansion of the ellipsoid and delay the clay-clogging effects,thereby considerably increasing the severity of sand loss,stratum deformation,and surface settlement.An increase in the confinedwater pressure markedly increases the hydraulic gradient along the seepage path,which contributes to increasing the gushing rates of water and sand.As a result,substantial sand loss occurs before the clay clogs the gushing crack,inducing more cracks and deeper sinkholes at the surface.All the aforementioned results provide insights into the effects of confinedaquifer on WSG disasters in clay aquiclude-confinedaquifer composite strata.展开更多
[Objective]The aim was to analyze the causes of low-temperature rain and snow disasters in 2008.[Method]Based on the basic meteorological observation data,a primary study was implemented about the severe cold air and ...[Objective]The aim was to analyze the causes of low-temperature rain and snow disasters in 2008.[Method]Based on the basic meteorological observation data,a primary study was implemented about the severe cold air and frozen rain event.The importance of factors causing disaster,territory and human activity in the formation of low-temperature rain and snow disasters were expounded.[Result]The factors triggering the disasters were so strong that were rarely seen in previous(stronger than that in 1954);the specific terrain was beneficial to the occurrence of the frozen rain;the human being’s action amplified the impacts of disaster events while suffering it.Furthermore,a point of view to minimize the climate disaster damage like this severe frozen rain was proposed.Improvement of forecast capability and accuracy,implementation of the demonstration about climatic feasibility,and propagation to public about the natural disaster’s protection and mitigation and so on were functional aspects.[Conclusion]The study provided theoretical basis for the prediction and forecast of low-temperature rain and snow disasters.展开更多
Snow and freezing disasters are recurrent weather and climate phenomena that affect the world annually.These events exert a significant influence on numerous aspects of life,including transportation,power supply,and d...Snow and freezing disasters are recurrent weather and climate phenomena that affect the world annually.These events exert a significant influence on numerous aspects of life,including transportation,power supply,and daily activities,and result in considerable economic losses.This study aims to provide a comprehensive analysis of the regions affected by these disasters,the preventive and responsive measures employed,recent advancements in key materials,and the challenges encountered.By doing so,we can gain a deeper understanding of the vital role,significant advantages,and untapped potential of key materials for effectively preventing and responding to snow and freezing disasters.Furthermore,promoting research and utilization of these materials not only contributes to the development of the safety and emergency equipment industry but also strengthens the supply of advanced and suitable safety and emergency equipment.展开更多
Electrochemical metallurgy at low temperature(<473 K)shows promise for the extraction and refinement of metals and alloys in a green and sustainable manner.However,the kinetics of the electrodeposition process is g...Electrochemical metallurgy at low temperature(<473 K)shows promise for the extraction and refinement of metals and alloys in a green and sustainable manner.However,the kinetics of the electrodeposition process is generally slow at low temperature,resulting in large overpotential and low current efficiency.Thus,the application of external physical fields has emerged as an effective strategy for improving the mass and charge transfer processes during electrochemical reactions.This review highlights the challenges associated with low-temperature electrochemical processes and briefly discusses recent achievements in optimizing electrodeposition processes through the use of external physical fields.The regulating effects on the optimization of the electrodeposition process and the strategies for select-ing various external physical fields,including magnetic,supergravity,and ultrasonic fields are summarized from the perspectives of equipment and mechanisms.Finally,advanced methods for in-situ characterization of external physical field-assisted electrodeposition processes are reviewed to gain a deeper understanding of metallic electrodeposition.An in-depth exploration of the mechanism by which external physical fields affect the electrode process is essential for enhancing the efficiency of metal extraction at low temperatures.展开更多
As centers of human activity,cities concentrate populations,resources,and wealth in limited areas.According to the United Nations,55%of the global population now lives in urban areas[1].Moreover,the World Economic Fo...As centers of human activity,cities concentrate populations,resources,and wealth in limited areas.According to the United Nations,55%of the global population now lives in urban areas[1].Moreover,the World Economic Forum’s“Global Risks Report 2023”[2]highlights natural disasters as a major threat to sustainable development,especially for densely populated cities.展开更多
Lithium-ion batteries are widely recognized as prime candidates for energy storage devices.Ethylene carbonate(EC)has become a critical component in conventional commercial electrolytes due to its exceptional film-form...Lithium-ion batteries are widely recognized as prime candidates for energy storage devices.Ethylene carbonate(EC)has become a critical component in conventional commercial electrolytes due to its exceptional film-forming properties and high dielectric constant.However,the elevated freezing point,high viscosity,and strong solvation energy of EC significantly hinder the transport rate of Li^(+)and the desolvation process at low temperatures.This leads to substantial capacity loss and even lithium plating on graphite anodes.Herein,we have developed an efficient electrolyte system specifically designed for lowtemperature conditions,which consists of 1.0 M lithium bis(fluorosulfonyl)imide(LiFSI)in isoxazole(IZ)with fluorobenzene(FB)as an uncoordinated solvent and fluoroethylene carbonate(FEC)as a filmforming co-solvent.This system effectively lowers the desolvation energy of Li^(+)through dipole-dipole interactions.The weak solvation capability allows more anions to enter the solvation sheath,promoting the formation of contact ion pairs(CIPs)and aggregates(AGGs)that enhance the transport rate of Li^(+)while maintaining high ionic conductivity across a broad temperature range.Moreover,the formation of inorganic-dominant interfacial phases on the graphite anode,induced by fluoroethylene carbonate,significantly enhances the kinetics of Li^(+)transport.At a low temperature of-20℃,this electrolyte system achieves an impressive reversible capacity of 200.9 mAh g^(-1)in graphite half-cell,which is nearly three times that observed with conventional EC-based electrolytes,demonstrating excellent stability throughout its operation.展开更多
To completely recover valuable elements and reduce the amount of waste,the impact of phosphoric acid on the decomposition of rare earth,fluorine and phosphorus during cyclic leaching was studied based on the character...To completely recover valuable elements and reduce the amount of waste,the impact of phosphoric acid on the decomposition of rare earth,fluorine and phosphorus during cyclic leaching was studied based on the characteristics of low-tempe rature sulfuric acid deco mposition.When a single monazite was leached using 75 wt% H_(2)SO_(4) solution with phosphoric acid,the size and number of monazite particles in the washing slag gradually decrease with the increase in phosphoric acid content in the leaching solution.The monazite phase can hardly be found in the slag when the phosphoric acid content reaches 70 g/L,which indicates that phosphoric acid is favorable for monazite decomposition.The mixed rare earth concentrate was leached by 75 wt% H_(2)SO_(4) containing 70 g/L phosphoric acid,the mineral compositions of the washing slag are only gypsum and unwashed rare earth sulfuric acid.After cyclic leaching of75 wt% H_(2)SO_(4),the mineral compositions of the primary leaching washing slag are mainly undecomposed monazite,rare earth sulfate and calcium sulfate.However,monazite is not found in the mineral phase of the second and third leaching washing slag.The leaching rates of rare earth and phosphorus gradually increase with the increase in cyclic leaching times.In addition,the phosphoric acid content in the leaching solution increases with the increase in the number of cyclic leaching time.However,the rising trend decreases when the phosphoric acid content reaches 50 g/L by adsorption and crystallization of phosphoric acid.A small amount of water can be used to clean the leaching residue before washing to recover the more soluble phosphorus acid according to the difference of dissolution between phosphoric acid and rare earth sulfuric acid.展开更多
Because of their excellent low-temperature(−15 to−40℃)tolerance,sodium-ion batteries are emerging as a complement to lithium-ion batteries for use in extremely cold environments(e.g.high-latitude areas).Hard carbon h...Because of their excellent low-temperature(−15 to−40℃)tolerance,sodium-ion batteries are emerging as a complement to lithium-ion batteries for use in extremely cold environments(e.g.high-latitude areas).Hard carbon has a high low-voltage sodium storage capacity and a good initial efficiency,making it one of the most promising anode materials for sodium-ion batteries.It has a complex structure,featuring closed pores,nano graphitic domains,and surface functional groups.The sodium storage sites in hard carbon are reviewed as are the widely accepted sodium storage mechanisms.The main factors contributing to the degradation of the good low-temperature performance in hard carbon anodes are considered,including sodium dendrite formation,low ion diffusion rates,and surface-side reactions.Finally,strategies to increase the low-temperature sodium storage performance of hard carbon anodes are summarized,including bulk structure design,and improvements in interfaces and cut-off voltage.Guidance is provided for improving the low-temperature performance of hard carbon anodes to accelerate the development of these batteries.展开更多
Aqueous zinc metal batteries(ZMBs)which are environmentally benign and cheap can be used for grid-scale energy storage,but have a short cycling life mainly due to the poor reversibility of zinc metal anodes in mild aq...Aqueous zinc metal batteries(ZMBs)which are environmentally benign and cheap can be used for grid-scale energy storage,but have a short cycling life mainly due to the poor reversibility of zinc metal anodes in mild aqueous electrolytes.A zincophilic carbon(ZC)layer was deposited on a Zn metal foil at 450°C by the up-stream pyrolysis of a hydrogen-bonded supramolecular substance framework,as-sembled from melamine(ME)and cyanuric acid(CA).The zincophilic groups(C=O and C=N)in the ZC layer guide uniform zinc plating/stripping and eliminate dendrites and side reactions.so that assembled symmetrical batteries(ZC@Zn//ZC@Zn)have a long-term service life of 2500 h at 1 mA cm^(−2) and 1 mAh cm^(−2),which is much longer than that of bare Zn anodes(180 h).In addition,ZC@Zn//V2O5 full batteries have a higher capacity of 174 mAh g^(−1) after 1200 cycles at 2 A g^(−1) than a Zn//V_(2)O_(5) counterpart(100 mAh g^(−1)).The strategy developed for the low-temperat-ure deposition of the ZC layer is a new way to construct advanced zinc metal anodes for ZMBs.展开更多
Background: Disaster preparedness is a critical aspect of nursing education, enhancing students’ ability to respond effectively in emergencies. However, the extent to which nursing curricula influence disaster prepar...Background: Disaster preparedness is a critical aspect of nursing education, enhancing students’ ability to respond effectively in emergencies. However, the extent to which nursing curricula influence disaster preparedness awareness remains underexplored. Our study found that 39% of students reported improved awareness after three years, highlighting the need for targeted curriculum enhancements. Purpose: To evaluate changes in disaster preparedness awareness among nursing students over three years of education and identify gaps in current curricula impacting this awareness. Results: Findings indicate that while 39% of students showed improved awareness, significant gaps remain, suggesting the need for a dedicated course on emergency preparedness. Conclusions: This study emphasizes the importance of integrating comprehensive disaster preparedness education within nursing curricula to address these gaps and foster resilience in future healthcare professionals.展开更多
At first glance(一瞥),10-year-old B.Kenit from the coastal town of Visakhapatnam in India looks like any other school-going child,but there is more than meets the eye.Inspired by a tsunami drill conducted in his schoo...At first glance(一瞥),10-year-old B.Kenit from the coastal town of Visakhapatnam in India looks like any other school-going child,but there is more than meets the eye.Inspired by a tsunami drill conducted in his school when he was eight,the third grader be-came a Disaster Risk Reduction(DRR)advocate,educating his fel-low students and community members on early warning,evacua-tion,and search and rescue.展开更多
Maize(Zea mays L.),a globally significant cereal crop,is produced in vast quantities worldwide.However,its growth is severely constrained by low temperatures,particularly during seed germination,which significantly im...Maize(Zea mays L.),a globally significant cereal crop,is produced in vast quantities worldwide.However,its growth is severely constrained by low temperatures,particularly during seed germination,which significantly impairs seedling emergence.In this study,genetic diversity across six germination-associated phenotypic traits(RGR,RSL,RTL,RRSA,RRV,and RSVI)of 304 inbred lines was analyzed,to evaluate the capacity of these lines for low-temperature tolerance.Genome-wide association study(GWAS)was carried out by combining six germination-associated phenotypic traits and genotypic data from 30-fold resequencing.The gene ZmBARK1 was identified through integrated GWAS and RNA-seq analyses,and its association with low-temperature tolerance during maize germination was validated by quantitative real-time PCR(qRT-PCR).ZmBARK1,encoding BRASSINOSTEROID INSENSITIVE 1-associated receptor kinase 1,was located on the bin 4.09 region of maize chromosome 4.Amino acid comparison and subcellular localization analyses revealed that ZmBARK1 is highly homologous to AtBAK1 and is localized to the plasma membrane of the cell,which may be involved in regulating brassinosteroid(BR)signaling.In addition,we revealed the role of ZmBARK1 in low-temperature tolerance during maize germination.Compared with wild-type(WT),the ethyl methanesulfonate(EMS)mutant zmbark1 was characterized by substantially enhanced low-temperature tolerance.Overall,these findings provide promising candidate genes,improve low-temperature tolerance in maize,and advance the understanding of regulatory mechanisms underlying maize's response to low-temperature stress.展开更多
Magnesium alloys are widely used in aerospace and automotive industries due to their lightweight.However,their poor fatigue performance limits the broader application,especially in dynamic stress environments.This stu...Magnesium alloys are widely used in aerospace and automotive industries due to their lightweight.However,their poor fatigue performance limits the broader application,especially in dynamic stress environments.This study explores novel coupled pretreatments of free-end largeangle pre-torsion and low-temperature aging to improve the fatigue resistance of rolled ZK60 magnesium alloy.STA(pre-torsion followed by low-temperature aging)and SAT(low-temperature aging followed by pre-torsion)samples were prepared to investigate the influences of pretreatment coupling sequences.The results of microstructure characterization reveal that pre-torsion significantly enhances the formation of tensile twins and introduces a gradient microstructure with increased dislocation density from the center to the edges.STA process resulted in the highest twinning area fraction of 35.2% and a kernel average misorientation of 0.94 at the edge.Mechanical testing demonstrated that the coupled pre-treatment obtained a better combination of strength and plasticity,significantly improved the yield strength in the compression stage,and increased the tensile-compressive yield ratio to>0.9.In the low-cycle fatigue test,the STA samples exhibited lower cyclic mean stress,a smaller cyclic hardening trend,and better hysteretic symmetry,leading to an improvement in fatigue life of up to 256%.The findings suggest that the combined pre-torsion and low-temperature aging treatments offer a promising approach to enhance the mechanical properties and fatigue resistance of ZK60 magnesium alloy,making it suitable for structural applications in demanding environments.展开更多
Abscisic acid(ABA)plays a key role in promoting the growth and development of plants,as well as mediating the responses of plants to adverse environmental conditions.Here,we measured the photosynthetic capacity of wil...Abscisic acid(ABA)plays a key role in promoting the growth and development of plants,as well as mediating the responses of plants to adverse environmental conditions.Here,we measured the photosynthetic capacity of wild-type RR,mutant sitiens(sit),and ABA-pretreated sit tomato seedlings following exposure to low-temperature(LT)stress.We found that the net photosynthetic rate,intercellular carbon dioxide concentration,transpiration rate,and stomatal conductance of sit seedlings were lower than those of RR seedlings under LT stress.The chloroplast width,area,and number of osmiophilic granules were significantly larger in sit seedlings than in RR seedlings,while the chloroplast length/width ratio was significantly lower in sit seedlings than in RR seedlings.The photochemical activity of sit seedlings was lower,and the expression of photosynthesis-related genes in sit seedlings was altered following exposure to LT stress.ABA pretreatment significantly alleviated the above phenomenon.We also conducted an RNA sequencing analysis and characterized the expression patterns of genes in tomato seedlings following exposure to LT stress.We constructed 15 cDNA libraries and identified several differentially expressed genes involved in photosynthesis,plant hormone signaling transduction,and primary and secondary metabolism.Additional analyses of genes encoding transcription factors and proteins involved in photosynthesis-related processes showed pronounced changes in expression under LT stress.Luciferase reporter assay and electrophoretic mobility shift assay revealed that WRKY22 regulates the expression of PsbA.The PSII of WRKY22 and PsbA-silenced plants was inhibited.Our findings indicate that ABA plays a role in regulating the process of photosynthesis and protecting PSII in tomato under LT stress through the WRKY22-PsbA complex.展开更多
基金Supported by China National Tobacco Corporation(Yunnan Tobacco Science and Technology Program No.[2014]302,program contract number:2014YN22)
文摘There is a prominent,complex and diverse three-dimensional climate and a variety of meteorological disasters in Qujing area. The risk zoning of low-temperature disasters for flue-cured tobacco planting in Qujing area was studied to provide reference for drawing on advantages and avoiding disadvantages in flue-cured tobacco planting,disaster reduction,and disaster relief services. According to the production practice of fluecured tobacco and local climate analysis,it was determined that flue-cured tobacco in Qujing area was very vulnerable to low temperature during the seedling stage（ from early February to middle April） and in the mature period（ from early July to early September）. Based on the quantitative analysis and evaluation of risk of disaster-causing factors,sensitivity of disaster-breeding environment,vulnerability of carriers,and disaster prevention and reduction capability,a risk assessment model of meteorological disasters was established to precisely evaluate and zone the risk of low-temperature disasters for flue-cured tobacco planting in allusion to the seedling and mature stage in Qujing area by using GIS technology. The risk of lowtemperature disasters for flue-cured tobacco planting during the two periods was divided into four grades,namely low,medium,high and very high risk.
文摘The modern world remains vulnerable to natural disasters,including floods,earthquakes,wildfires,and others.These events remain unpredictable and inevitable,and recovering quickly and effectively requires significant effort and expense.Monitoring is becoming more efficient thanks to technologies such as Unmanned Aerial Vehicles(UAVs),which can access hard-to-reach areas and provide real-time data.However,in disaster-affected areas,these monitoring systems may encounter many obstacles when communicating with servers or transmitting monitored data.This paper proposes an adaptive communication model to overcome the challenges faced in disaster-affected areas.A base station is responsible for collecting data(such as images and videos)captured by UAVs performing surveillance within its communication range.This station is typically a tower providing fixed cellular network service.However,in the absence of such a tower,a selected UAV may serve as the station,depending on the situation.If surveillance needs to be performed outside the coverage area,it can continue to communicate via nearby UAVs through cooperative communication.UAVs with internet support,known as the Internet of Flying Things(IoFT),will also be utilized to enhance communication capacity and efficiency.The proposed communication model is validated through experiments,showing superior data transmission performance and higher throughput.Analysis indicates it outperforms traditional systems,even in rural areas,with or without internet access.
基金the National Natural Science Foundation of China,grant number 52406074the China Postdoctoral Science Foundation under Grant Number 2025T180171+1 种基金the Natural Science Foundation of Guangdong Province(2025A1515011270)the China Southern Power Grid Technology Project(GDKJXM20231415/030100KC23120104).
文摘In order to explore the effects of CaO,lignite dust and sawdust on the drying characteristics ofmunicipal sludge at different concentrations,a three-factor three-level regression experiment was carried out based on the results of thermogravimetric experiment and single factor experiment.By fitting three common mathematical models,the Page model with the highest fitting degree was selected to determine the most suitable mathematical model to describe the municipal sludge drying process.In addition,the Box-Behnken design principle in the response surface method was used to analyze the interaction of three factors on the drying characteristics of municipal sludge.The results of the study show that below 100℃is the optimal drying temperature range for municipal sludge.The results of single factor experiments showed that the order of influence of the three factors on sludge drying time was CaO concentration>sawdust concentration>lignite dust concentration.In the single factor experiment,the optimal process parameterswere CaOconcentration 3%,lignite powder concentration 7%,and sawdust concentration 7%.In themulti-factor interaction analysis,the interaction between CaO and sawdust had the most significant effect on the reduction of drying time,and the order of influence was as follows:CaO interaction with sawdust>lignite dust interaction with sawdust>CaO interaction with lignite powder.Further analysis showed that the optimal process ratio was 3%CaO concentration and 3%sawdust concentration.
基金the financial support from the Key Project of Shaanxi Provincial Natural Science Foundation-Key Project of Laboratory(2025SYS-SYSZD-117)the Natural Science Basic Research Program of Shaanxi(2025JCYBQN-125)+8 种基金Young Talent Fund of Xi'an Association for Science and Technology(0959202513002)the Key Industrial Chain Technology Research Program of Xi'an(24ZDCYJSGG0048)the Key Research and Development Program of Xianyang(L2023-ZDYF-SF-077)Postdoctoral Fellowship Program of CPSF(GZC20241442)Shaanxi Postdoctoral Science Foundation(2024BSHSDZZ070)Research Funds for the Interdisciplinary Projects,CHU(300104240913)the Fundamental Research Funds for the Central Universities,CHU(300102385739,300102384201,300102384103)the Scientific Innovation Practice Project of Postgraduate of Chang'an University(300103725063)the financial support from the Australian Research Council。
文摘Lithium-ion batteries(LIBs),while dominant in energy storage due to high energy density and cycling stability,suffer from severe capacity decay,rate capability degradation,and lithium dendrite formation under low-temperature(LT)operation.Therefore,a more comprehensive and systematic understanding of LIB behavior at LT is urgently required.This review article comprehensively reviews recent advancements in electrolyte engineering strategies aimed at improving the low-temperature operational capabilities of LIBs.The study methodically examines critical performance-limiting mechanisms through fundamental analysis of four primary challenges:insufficient ionic conductivity under cryogenic conditions,kinetically hindered charge transfer processes,Li+transport limitations across the solidelectrolyte interphase(SEI),and uncontrolled lithium dendrite growth.The work elaborates on innovative optimization approaches encompassing lithium salt molecular design with tailored dissociation characteristics,solvent matrix optimization through dielectric constant and viscosity regulation,interfacial engineering additives for constructing low-impedance SEI layers,and gel-polymer composite electrolyte systems.Notably,particular emphasis is placed on emerging machine learning-guided electrolyte formulation strategies that enable high-throughput virtual screening of constituent combinations and prediction of structure-property relationships.These artificial intelligence-assisted rational design frameworks demonstrate significant potential for accelerating the development of next-generation LT electrolytes by establishing quantitative composition-performance correlations through advanced data-driven methodologies.
基金financially supported by the National Natural Science Foundation of China(No.22309067)the Open Project Program of the State Key Laboratory of Materials-Oriented Chemical Engineering,China(No.KL21-05)the Marine Equipment and Technology Institute,Jiangsu University of Science and Technology,China(No.XTCX202404)。
文摘This study focused on improving the cathode performance of Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.15)O_(3-δ)(BSCN)-based perovskite materials through molybdenum(Mo)doping.Pure BSCN and Mo-modified-BSCN—Ea_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.1)Mo_(0.05)O_(3-δ)(B S CNM_(0.05)),Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.05)Mo_(0.1)O_(3-δ)(BSCNM_(0.1)),and Ba_(0.6)Sr_(0.4)Co_(0.85)Mo_(0.15)O_(3-δ)(BSCM)—with Mo doping contents of 5mol%,10mol%,and15mol%,respectively,were successfully prepared using the sol-gel method.The effects of Mo doping on the crystal structure,conductivity,thermal expansion coefficient,oxygen reduction reaction(ORR)activity,and electrochemical performance were systematically evaluated using X-ray diffraction analysis,thermally induced characterization,electrochemical impedance spectroscopy,and single-cell performance tests.The results revealed that Mo doping could improve the conductivity of the materials,suppress their thermal expansion effects,and significantly improve the electrochemical performance.Surface chemical state analysis using X-ray photoelectron spectroscopy revealed that 5mol%Mo doping could facilitate a high adsorbed oxygen concentration leading to enhanced ORR activity in the materials.Density functional theory calculations confirmed that Mo doping promoted the ORR activity in the materials.At an operating temperature of 600℃,the BSCNM_(0.05)cathode material exhibited significantly enhanced electrochemical impedance characteristics,with a reduced area specific resistance of 0.048Ω·cm~2,which was lower than that of the undoped BSCN matrix material by 32.39%.At the same operating temperature,an anode-supported single cell using a BSCNM_(0.05)cathode achieved a peak power density of 1477 mW·cm^(-2),which was 30.71%,56.30%,and 171.50%higher than those of BSCN,BSCNM_(0.1),and B SCM,respectively.The improved ORR activity and electrochemical performance of BSCNM_(0.05)indicate that it can be used as a cathode material in low-temperature solid oxide fuel cells.
基金National Natural Science Foundation of China Grant Nos.52378543,52378544 and 52408525the Natural Science Foundation of Heilongjiang Grant No.LH2024E119。
文摘On December 18,2023,a magnitude 6.2 earthquake struck Jishishan County,Gansu Province,triggering a liquefaction-induced flow slide along the loess-mudstone contact zone and causing significant casualties and property losses.The event featured low-slope,large-scale,runout distance sliding and exhibited a clear cascading disaster chain.Its characteristics closely resemble the catastrophic mudflow at the nearby Lajia Ruins approximately 4,000 years ago.Using high-resolution oblique photogrammetry,cone penetration testing,surface wave analysis,and horizontal-to-vertical spectral ratio methods,this study examines the stratigraphy,groundwater conditions,and geomechanical properties of the affected zone.Results indicate that saturated loess overlying impermeable mudstone formed a high-moisture mass vulnerable to seismic disturbance.Seismic resonance triggered the liquefaction of weakly structured loess,which slide along the contact interface and evolved into a runout distance mudflow.Underground water and terrain modification created a composite weak zone of saturated loess and softened mudstone,which intensified the disaster chain-from earthquake to liquefaction,flow slide,and mudflow.This study contributes to the understanding of deep-seated liquefaction-flow slide disasters,thereby advancing more effective risk mitigation strategies in the Loess Plateau and comparable loess-covered seismic regions.
基金financedby the National Natural Science Foundation of China(Grant No.52090083)the Shanghai Rising-Star Program(Grant No.23QB1404800).
文摘Water-sand gushing(WSG)disasters in confinedaquifers pose significantchallenges to the utilization of deep underground spaces in soft soil areas.Since few studies have considered the impact of confined aquifer thickness and confinedwater pressure on WSG disasters,a novel visual model test system was developed to investigate the influencingcharacteristics and mechanisms of the two aforementioned factors.The test results showed that the WSG process in clay aquiclude-confinedaquifer composite strata exhibits two prominent stages.First,the sand loss zone expands vertically in an ellipsoid shape.Then,it expands horizontally once the ellipsoid reaches the boundary of the clay layer.The sand loss continues until the overlying clay sinks to the bottom to clog the gushing crack,creating a large sinkhole at the surface.Increasing the confinedaquifer thickness can increase the vertical expansion of the ellipsoid and delay the clay-clogging effects,thereby considerably increasing the severity of sand loss,stratum deformation,and surface settlement.An increase in the confinedwater pressure markedly increases the hydraulic gradient along the seepage path,which contributes to increasing the gushing rates of water and sand.As a result,substantial sand loss occurs before the clay clogs the gushing crack,inducing more cracks and deeper sinkholes at the surface.All the aforementioned results provide insights into the effects of confinedaquifer on WSG disasters in clay aquiclude-confinedaquifer composite strata.
基金Supported by Chinese Meteorological Bureau Business Program in 2009"National Meteorological Disaster Risk Zone"Hunan Province Meteorological Bureau Key Science and Research Program(200801)
文摘[Objective]The aim was to analyze the causes of low-temperature rain and snow disasters in 2008.[Method]Based on the basic meteorological observation data,a primary study was implemented about the severe cold air and frozen rain event.The importance of factors causing disaster,territory and human activity in the formation of low-temperature rain and snow disasters were expounded.[Result]The factors triggering the disasters were so strong that were rarely seen in previous(stronger than that in 1954);the specific terrain was beneficial to the occurrence of the frozen rain;the human being’s action amplified the impacts of disaster events while suffering it.Furthermore,a point of view to minimize the climate disaster damage like this severe frozen rain was proposed.Improvement of forecast capability and accuracy,implementation of the demonstration about climatic feasibility,and propagation to public about the natural disaster’s protection and mitigation and so on were functional aspects.[Conclusion]The study provided theoretical basis for the prediction and forecast of low-temperature rain and snow disasters.
基金supported by the National Natural Science Foundation of China(Nos.52273220 and 22205243)。
文摘Snow and freezing disasters are recurrent weather and climate phenomena that affect the world annually.These events exert a significant influence on numerous aspects of life,including transportation,power supply,and daily activities,and result in considerable economic losses.This study aims to provide a comprehensive analysis of the regions affected by these disasters,the preventive and responsive measures employed,recent advancements in key materials,and the challenges encountered.By doing so,we can gain a deeper understanding of the vital role,significant advantages,and untapped potential of key materials for effectively preventing and responding to snow and freezing disasters.Furthermore,promoting research and utilization of these materials not only contributes to the development of the safety and emergency equipment industry but also strengthens the supply of advanced and suitable safety and emergency equipment.
基金supported by Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(No.SML2023SP243)the National Key Research and Development Program of China(No.2022YFC2906100)the National Natural Science Foundation of China(No.92475202)are acknowledged.
文摘Electrochemical metallurgy at low temperature(<473 K)shows promise for the extraction and refinement of metals and alloys in a green and sustainable manner.However,the kinetics of the electrodeposition process is generally slow at low temperature,resulting in large overpotential and low current efficiency.Thus,the application of external physical fields has emerged as an effective strategy for improving the mass and charge transfer processes during electrochemical reactions.This review highlights the challenges associated with low-temperature electrochemical processes and briefly discusses recent achievements in optimizing electrodeposition processes through the use of external physical fields.The regulating effects on the optimization of the electrodeposition process and the strategies for select-ing various external physical fields,including magnetic,supergravity,and ultrasonic fields are summarized from the perspectives of equipment and mechanisms.Finally,advanced methods for in-situ characterization of external physical field-assisted electrodeposition processes are reviewed to gain a deeper understanding of metallic electrodeposition.An in-depth exploration of the mechanism by which external physical fields affect the electrode process is essential for enhancing the efficiency of metal extraction at low temperatures.
基金the Ministry of Science and Technology National Key Research and Development Program(2023YFC3805000)the National Natural Science Foundation of China(52025083 and 52208501)the Shanghai Science and Technology Innovation Action Plan(22dz1201400).
文摘As centers of human activity,cities concentrate populations,resources,and wealth in limited areas.According to the United Nations,55%of the global population now lives in urban areas[1].Moreover,the World Economic Forum’s“Global Risks Report 2023”[2]highlights natural disasters as a major threat to sustainable development,especially for densely populated cities.
基金financial support from the Department of Science and Technology of Jilin Province(20240304104SF,20240304103SF)the Research and Innovation Fund of the Beihua University for the Graduate Student(Major Project 2023012)。
文摘Lithium-ion batteries are widely recognized as prime candidates for energy storage devices.Ethylene carbonate(EC)has become a critical component in conventional commercial electrolytes due to its exceptional film-forming properties and high dielectric constant.However,the elevated freezing point,high viscosity,and strong solvation energy of EC significantly hinder the transport rate of Li^(+)and the desolvation process at low temperatures.This leads to substantial capacity loss and even lithium plating on graphite anodes.Herein,we have developed an efficient electrolyte system specifically designed for lowtemperature conditions,which consists of 1.0 M lithium bis(fluorosulfonyl)imide(LiFSI)in isoxazole(IZ)with fluorobenzene(FB)as an uncoordinated solvent and fluoroethylene carbonate(FEC)as a filmforming co-solvent.This system effectively lowers the desolvation energy of Li^(+)through dipole-dipole interactions.The weak solvation capability allows more anions to enter the solvation sheath,promoting the formation of contact ion pairs(CIPs)and aggregates(AGGs)that enhance the transport rate of Li^(+)while maintaining high ionic conductivity across a broad temperature range.Moreover,the formation of inorganic-dominant interfacial phases on the graphite anode,induced by fluoroethylene carbonate,significantly enhances the kinetics of Li^(+)transport.At a low temperature of-20℃,this electrolyte system achieves an impressive reversible capacity of 200.9 mAh g^(-1)in graphite half-cell,which is nearly three times that observed with conventional EC-based electrolytes,demonstrating excellent stability throughout its operation.
基金support by the National Natural Science Foundation of Inner Mongolia (2022SHZR1885)Natural Science Foundation of Hebei province (E2022402101,E2022402105)。
文摘To completely recover valuable elements and reduce the amount of waste,the impact of phosphoric acid on the decomposition of rare earth,fluorine and phosphorus during cyclic leaching was studied based on the characteristics of low-tempe rature sulfuric acid deco mposition.When a single monazite was leached using 75 wt% H_(2)SO_(4) solution with phosphoric acid,the size and number of monazite particles in the washing slag gradually decrease with the increase in phosphoric acid content in the leaching solution.The monazite phase can hardly be found in the slag when the phosphoric acid content reaches 70 g/L,which indicates that phosphoric acid is favorable for monazite decomposition.The mixed rare earth concentrate was leached by 75 wt% H_(2)SO_(4) containing 70 g/L phosphoric acid,the mineral compositions of the washing slag are only gypsum and unwashed rare earth sulfuric acid.After cyclic leaching of75 wt% H_(2)SO_(4),the mineral compositions of the primary leaching washing slag are mainly undecomposed monazite,rare earth sulfate and calcium sulfate.However,monazite is not found in the mineral phase of the second and third leaching washing slag.The leaching rates of rare earth and phosphorus gradually increase with the increase in cyclic leaching times.In addition,the phosphoric acid content in the leaching solution increases with the increase in the number of cyclic leaching time.However,the rising trend decreases when the phosphoric acid content reaches 50 g/L by adsorption and crystallization of phosphoric acid.A small amount of water can be used to clean the leaching residue before washing to recover the more soluble phosphorus acid according to the difference of dissolution between phosphoric acid and rare earth sulfuric acid.
文摘Because of their excellent low-temperature(−15 to−40℃)tolerance,sodium-ion batteries are emerging as a complement to lithium-ion batteries for use in extremely cold environments(e.g.high-latitude areas).Hard carbon has a high low-voltage sodium storage capacity and a good initial efficiency,making it one of the most promising anode materials for sodium-ion batteries.It has a complex structure,featuring closed pores,nano graphitic domains,and surface functional groups.The sodium storage sites in hard carbon are reviewed as are the widely accepted sodium storage mechanisms.The main factors contributing to the degradation of the good low-temperature performance in hard carbon anodes are considered,including sodium dendrite formation,low ion diffusion rates,and surface-side reactions.Finally,strategies to increase the low-temperature sodium storage performance of hard carbon anodes are summarized,including bulk structure design,and improvements in interfaces and cut-off voltage.Guidance is provided for improving the low-temperature performance of hard carbon anodes to accelerate the development of these batteries.
基金partially supported by the National Natural Science Foundation of China(22479022)Liaoning Revitalization Talents Program(XLYC2007129)。
文摘Aqueous zinc metal batteries(ZMBs)which are environmentally benign and cheap can be used for grid-scale energy storage,but have a short cycling life mainly due to the poor reversibility of zinc metal anodes in mild aqueous electrolytes.A zincophilic carbon(ZC)layer was deposited on a Zn metal foil at 450°C by the up-stream pyrolysis of a hydrogen-bonded supramolecular substance framework,as-sembled from melamine(ME)and cyanuric acid(CA).The zincophilic groups(C=O and C=N)in the ZC layer guide uniform zinc plating/stripping and eliminate dendrites and side reactions.so that assembled symmetrical batteries(ZC@Zn//ZC@Zn)have a long-term service life of 2500 h at 1 mA cm^(−2) and 1 mAh cm^(−2),which is much longer than that of bare Zn anodes(180 h).In addition,ZC@Zn//V2O5 full batteries have a higher capacity of 174 mAh g^(−1) after 1200 cycles at 2 A g^(−1) than a Zn//V_(2)O_(5) counterpart(100 mAh g^(−1)).The strategy developed for the low-temperat-ure deposition of the ZC layer is a new way to construct advanced zinc metal anodes for ZMBs.
文摘Background: Disaster preparedness is a critical aspect of nursing education, enhancing students’ ability to respond effectively in emergencies. However, the extent to which nursing curricula influence disaster preparedness awareness remains underexplored. Our study found that 39% of students reported improved awareness after three years, highlighting the need for targeted curriculum enhancements. Purpose: To evaluate changes in disaster preparedness awareness among nursing students over three years of education and identify gaps in current curricula impacting this awareness. Results: Findings indicate that while 39% of students showed improved awareness, significant gaps remain, suggesting the need for a dedicated course on emergency preparedness. Conclusions: This study emphasizes the importance of integrating comprehensive disaster preparedness education within nursing curricula to address these gaps and foster resilience in future healthcare professionals.
文摘At first glance(一瞥),10-year-old B.Kenit from the coastal town of Visakhapatnam in India looks like any other school-going child,but there is more than meets the eye.Inspired by a tsunami drill conducted in his school when he was eight,the third grader be-came a Disaster Risk Reduction(DRR)advocate,educating his fel-low students and community members on early warning,evacua-tion,and search and rescue.
基金supported by the Key Research and Development Project of Heilongjiang Province(2022ZX02B01)the Natural Science Foundation Project of Heilongjiang Province(YQ2022C009)the Natural Science Foundation of Shandong Province(K22LB56)。
文摘Maize(Zea mays L.),a globally significant cereal crop,is produced in vast quantities worldwide.However,its growth is severely constrained by low temperatures,particularly during seed germination,which significantly impairs seedling emergence.In this study,genetic diversity across six germination-associated phenotypic traits(RGR,RSL,RTL,RRSA,RRV,and RSVI)of 304 inbred lines was analyzed,to evaluate the capacity of these lines for low-temperature tolerance.Genome-wide association study(GWAS)was carried out by combining six germination-associated phenotypic traits and genotypic data from 30-fold resequencing.The gene ZmBARK1 was identified through integrated GWAS and RNA-seq analyses,and its association with low-temperature tolerance during maize germination was validated by quantitative real-time PCR(qRT-PCR).ZmBARK1,encoding BRASSINOSTEROID INSENSITIVE 1-associated receptor kinase 1,was located on the bin 4.09 region of maize chromosome 4.Amino acid comparison and subcellular localization analyses revealed that ZmBARK1 is highly homologous to AtBAK1 and is localized to the plasma membrane of the cell,which may be involved in regulating brassinosteroid(BR)signaling.In addition,we revealed the role of ZmBARK1 in low-temperature tolerance during maize germination.Compared with wild-type(WT),the ethyl methanesulfonate(EMS)mutant zmbark1 was characterized by substantially enhanced low-temperature tolerance.Overall,these findings provide promising candidate genes,improve low-temperature tolerance in maize,and advance the understanding of regulatory mechanisms underlying maize's response to low-temperature stress.
基金sponsored by the National Natural Science Foundation of China(Nos.52175143,and 51571150).
文摘Magnesium alloys are widely used in aerospace and automotive industries due to their lightweight.However,their poor fatigue performance limits the broader application,especially in dynamic stress environments.This study explores novel coupled pretreatments of free-end largeangle pre-torsion and low-temperature aging to improve the fatigue resistance of rolled ZK60 magnesium alloy.STA(pre-torsion followed by low-temperature aging)and SAT(low-temperature aging followed by pre-torsion)samples were prepared to investigate the influences of pretreatment coupling sequences.The results of microstructure characterization reveal that pre-torsion significantly enhances the formation of tensile twins and introduces a gradient microstructure with increased dislocation density from the center to the edges.STA process resulted in the highest twinning area fraction of 35.2% and a kernel average misorientation of 0.94 at the edge.Mechanical testing demonstrated that the coupled pre-treatment obtained a better combination of strength and plasticity,significantly improved the yield strength in the compression stage,and increased the tensile-compressive yield ratio to>0.9.In the low-cycle fatigue test,the STA samples exhibited lower cyclic mean stress,a smaller cyclic hardening trend,and better hysteretic symmetry,leading to an improvement in fatigue life of up to 256%.The findings suggest that the combined pre-torsion and low-temperature aging treatments offer a promising approach to enhance the mechanical properties and fatigue resistance of ZK60 magnesium alloy,making it suitable for structural applications in demanding environments.
基金supported by the National Natural Science Foundation of China(32272791 and 32072651)the earmarked fund for CARS(CARS-23)+1 种基金the Joint Fund for Innovation Enhancement of Liaoning Province,China(2021-NLTS-11-01)the support program for Young and Middle-aged Scientific and Technological Innovation Talents,China(RC210293)。
文摘Abscisic acid(ABA)plays a key role in promoting the growth and development of plants,as well as mediating the responses of plants to adverse environmental conditions.Here,we measured the photosynthetic capacity of wild-type RR,mutant sitiens(sit),and ABA-pretreated sit tomato seedlings following exposure to low-temperature(LT)stress.We found that the net photosynthetic rate,intercellular carbon dioxide concentration,transpiration rate,and stomatal conductance of sit seedlings were lower than those of RR seedlings under LT stress.The chloroplast width,area,and number of osmiophilic granules were significantly larger in sit seedlings than in RR seedlings,while the chloroplast length/width ratio was significantly lower in sit seedlings than in RR seedlings.The photochemical activity of sit seedlings was lower,and the expression of photosynthesis-related genes in sit seedlings was altered following exposure to LT stress.ABA pretreatment significantly alleviated the above phenomenon.We also conducted an RNA sequencing analysis and characterized the expression patterns of genes in tomato seedlings following exposure to LT stress.We constructed 15 cDNA libraries and identified several differentially expressed genes involved in photosynthesis,plant hormone signaling transduction,and primary and secondary metabolism.Additional analyses of genes encoding transcription factors and proteins involved in photosynthesis-related processes showed pronounced changes in expression under LT stress.Luciferase reporter assay and electrophoretic mobility shift assay revealed that WRKY22 regulates the expression of PsbA.The PSII of WRKY22 and PsbA-silenced plants was inhibited.Our findings indicate that ABA plays a role in regulating the process of photosynthesis and protecting PSII in tomato under LT stress through the WRKY22-PsbA complex.
