Due to the wet-dry cycling in the ocean tidal zone,the supply of dissolved oxygen and salt-containing particles were sufficient,so the corrosion was serious.Pitting corrosion was a common form of localized corrosion.T...Due to the wet-dry cycling in the ocean tidal zone,the supply of dissolved oxygen and salt-containing particles were sufficient,so the corrosion was serious.Pitting corrosion was a common form of localized corrosion.This paper studied the pitting corrosion mechanism of dispersion-strengthened high-strength steel under different wet-dry ratio environments.Electrochemical Impedance Spectroscopy was used to study the changes of corrosion rate and electric double layer structure of the dispersionstrengthened high-strength steel.Scanning electron microscope,Raman spectroscopy,electron probe microanalysis and laser confocal scanning microscope were used to observe the corrosion product morphologies,analyze the corrosion product compositions,analyze the secondary distribution of alloy elements in the corrosion products and analyze the pitting information of the steel after the corrosion products were removed.The results showed that the degree of the steel corrosion was slight when the wetting time was longer,the size and depth of the corrosion pits on the surface were smaller.This was because the environment with longer wetting time made the corrosion products denser.In this environment,the conversion ofγ-FeOOH to Fe3O4 was promoted.In addition,it could also promote the alloying elements to be more concentrated in the rust layer.The above phenomena hindered the further corrosion of the matrix by dissolved oxygen and Cl−in the seawater.展开更多
Microstructures and properties of mortar using ammonium phosphate and potassium phosphate were tested and compared in this case.Moreover,two cementitious additions and two lightweight aggregates,including fly ash,redi...Microstructures and properties of mortar using ammonium phosphate and potassium phosphate were tested and compared in this case.Moreover,two cementitious additions and two lightweight aggregates,including fly ash,redispersible latex powder,ceramsite sand,and rubber powder,were respectively tried to be applied in magnesium ammonium phosphate cement mortar in order to modify the microstructures and properties.The experimental results show that potassium phosphate is not suitable for magnesium phosphate cement mortar for cold region construction purpose.Although fly ash can bring positive modification in the condition of normal temperature curing,it brings negative effects in the condition of sub-zero temperature curing.Either redispersible latex powder or ceramsite sand can improve the freeze-thaw cycling resistance of magnesium phosphate cement mortar in the conditions of low temperature coupled with freeze-thaw cycling,but only the ceramsite sand can improve both mechanical properties and freeze-thaw cycling resistance.The modification caused by ceramsite sand is mainly due to the exceptional bonding strength between hardened cement paste and the porous surface of ceramsite and the porous structure of ceramsite for the release of frost heave stress.展开更多
Approximately 3.44 billion tons of copper mine tailings(MT)were produced globally in 2018 with an increase of 45%from 2010.Significant efforts are being made to manage these tailings through storage facilities,recycli...Approximately 3.44 billion tons of copper mine tailings(MT)were produced globally in 2018 with an increase of 45%from 2010.Significant efforts are being made to manage these tailings through storage facilities,recycling,and reuse in different industries.Currently,a large portion of tailings are managed through the tailing storage facilities(TSF)where these tailings undergo hydro-thermal-mechanical stresses with seasonal cycles which are not comprehensively understood.This study presents an investigative study to evaluate the performance of control and cement-stabilized copper MT under the influence of seasonal cycles,freeze-thaw(F-T)and wet-dry(W-D)conditions,representing the seasonal variability in the cold and arid regions.The control and cement-stabilized MT samples were subjected to a maximum of 12 F-T and 12 W-D cycles and corresponding micro-and-macro behavior was investigated through scanning electron microscope(SEM),volumetric strain(εvT,wet density(r),moisture content loss,and unconfined compressive strength(UCS)tests.The results indicated the vulnerability of Copper MT to 67%and 75%strength loss reaching residual states with 12 F-T and 8 W-D cycles,respectively.Whereas the stabilized MT retained 39%-55%and 16%-34%strength with F-T and W-D cycles,demonstrating increased durability.This research highlights the impact of seasonal cycles and corresponding strength-deformation characteristics of control and stabilized Copper MT in cold and arid regions.展开更多
The study focuses on the creep characteristics of significant yellow sandstone for water conservancy, hydropower, and other waterrelated slope excavation unloading rock-graded loading creep characteristics. It conduct...The study focuses on the creep characteristics of significant yellow sandstone for water conservancy, hydropower, and other waterrelated slope excavation unloading rock-graded loading creep characteristics. It conducts a uniaxial graded loading creep test on yellow sandstone under different pre-peak unloading and wetting-drying cycles. The improved nonlinear Nishihara model was obtained by introducing a nonlinear viscous element with an accelerated creep threshold switch. The sensitivity characteristics of the parameters of the improved creep model were analyzed and a nonlinear creep constitutive model was established, considering the unloading-cyclic intrinsic damage induced by water intrusion. The research results show that:(1)With an increase in the unloading point, the porosity of the rock samples initially decreases and then increases. As the number of cyclic water intrusions rises, the porosity of the rock samples gradually increases, reaching a maximum of 9.58% at an unloading point of 70% uniaxial compression stress(0.7 Rc) after five cycles.(2) Total creep deformation increases with the number of cyclic water intrusions;however, with an increase in the unloading ratio, the original samples show an initial decrease, followed by an increase in creep deformation. With a higher unloading ratio and various instances of cyclic water intrusion, the total creep time of the rock samples,compared to the original samples, is reduced by 21.8%and 23.02%. The creep damage mode gradually changes from shear damage to tensile damage.(3) The sensitivity characteristics of the improved creep model parameters show that transient elasticity modulus E1 is affected by the coupling of unloading and cyclic water intrusion. The viscoelastic modulus E2 and viscous coefficient η1 are mainly affected by unloading and cyclic water intrusion.(4) Based on the strain equivalence principle of damage mechanics, the damage treatment of the parameters in the original model is improved to construct a nonlinear creep constitutive model that considers unloading-cyclic water intrusion damage. A parameter inversion and comparison to the traditional Nishihara model reveal an average relative standard deviation of 0.271%,significantly less than 1%, indicating a more accurate nonlinear creep constitutive model. The research results are crucial for analyzing the long-term stability of water-related steep rocky slopes post-excavation and unloading and for preventing and controlling creep-type landslide disasters.展开更多
The pursuit of safer and high-performance lithium-ion batteries(LIBs)has triggered extensive research activities on solid-state batteries,while challenges related to the unstable electrode-electrolyte interface hinder...The pursuit of safer and high-performance lithium-ion batteries(LIBs)has triggered extensive research activities on solid-state batteries,while challenges related to the unstable electrode-electrolyte interface hinder their practical implementation.Polymer has been used extensively to improve the cathode-electrolyte interface in garnet-based all-solid-state LIBs(ASSLBs),while it introduces new concerns about thermal stability.In this study,we propose the incorporation of a multi-functional flame-retardant triphenyl phos-phate additive into poly(ethylene oxide),acting as a thin buffer layer between LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)cathode and garnet electro-lyte.Through electrochemical stability tests,cycling performance evaluations,interfacial thermal stability analysis and flammability tests,improved thermal stability(capacity retention of 98.5%after 100 cycles at 60℃,and 89.6%after 50 cycles at 80℃)and safety characteristics(safe and stable cycling up to 100℃)are demonstrated.Based on various materials characterizations,the mechanism for the improved thermal stability of the interface is proposed.The results highlight the potential of multi-functional flame-retardant additives to address the challenges associated with the electrode-electrolyte interface in ASSLBs at high temperature.Efficient thermal modification in ASSLBs operating at elevated temperatures is also essential for enabling large-scale energy storage with safety being the primary concern.展开更多
心脏磁共振成像(cardiac magnetic resonance,CMR)过程中患者误动、异常幅度的呼吸运动、心律失常会造成CMR图像质量下降,为解决现有的CMR图像增强网络需要人为制作配对数据,且图像增强后部分组织纹理细节丢失的问题,提出了基于空频域...心脏磁共振成像(cardiac magnetic resonance,CMR)过程中患者误动、异常幅度的呼吸运动、心律失常会造成CMR图像质量下降,为解决现有的CMR图像增强网络需要人为制作配对数据,且图像增强后部分组织纹理细节丢失的问题,提出了基于空频域特征学习的循环一致性生成对抗网络(cycle-consistent generative adversavial network based on spatial-frequency domain feature learning,SFFL-CycleGAN).研究结果表明,该网络无须人为制作配对数据集,增强后的CMR图像组织纹理细节丰富,在结构相似度(structural similarity,SSIM)和峰值信噪比(peak signal to noise ratio,PSNR)等方面均优于现有的配对训练网络以及原始的CycleGAN网络,图像增强效果好,有效助力病情诊断.展开更多
Plastic mulches have become an essential component of modern agriculture since their introduction in the 1950s.However,disposal of plastic mulches poses serious environmental challenges as plastics that are not consid...Plastic mulches have become an essential component of modern agriculture since their introduction in the 1950s.However,disposal of plastic mulches poses serious environmental challenges as plastics that are not considered biodegradable or compostable can take several hundred years to degrade.Each year in the United States,only 9%of overall plastic waste is recycled while 79%is accumulated in landfills or the natural environment.Recycling of plastic mulch is especially constrained due to the contamination that results from their use in farming.Currently,recovered mulches are reported to have 30%–80%surface contamination,primarily from soil and plant debris.Plastic mulch waste is concentrated in areas where they are used and can provide logistical opportunities to the plastic recycling industries.Plastic recycling includes mechanical,advanced(chemical and thermal),and biological methods,that may all be used for polyethylene(PE).Most plastic is recycled using the mechanical method,while advanced and biological methods are promising but face significant financial and technical challenges.For all recycling methods,strategies are needed for managing surface contamination to realize the recycling potential of plastic mulch.展开更多
In January 2018,construction wrapped on Salesforce Tower(Fig.1),a 61-story office building that now dominates the skyline of San Francisco,CA,USA.In addition to being the tallest building in the city,Salesforce Tower ...In January 2018,construction wrapped on Salesforce Tower(Fig.1),a 61-story office building that now dominates the skyline of San Francisco,CA,USA.In addition to being the tallest building in the city,Salesforce Tower is the largest structure in the world with an onsite water recycling system.Built by the Australian com-pany Aquacell(Milton,NSW,Australia),the system cleans 113 m^(3)of sewage,sink,shower,and other wastewater each day for use in irrigation and flushing toilets,saving an estimated 35000 m?of water anmually[1].The building is just one of dozens in San Fran-cisco outitted with their own water recycling systems,thanks to a city mandate enacted in 2015[1].展开更多
Ameloblastoma is a benign tumor characterized by locally invasive phenotypes,leading to facial bone destruction and a high recurrence rate.However,the mechanisms governing tumor initiation and recurrence are poorly un...Ameloblastoma is a benign tumor characterized by locally invasive phenotypes,leading to facial bone destruction and a high recurrence rate.However,the mechanisms governing tumor initiation and recurrence are poorly understood.Here,we uncovered cellular landscapes and mechanisms that underlie tumor recurrence in ameloblastoma at single-cell resolution.Our results revealed that ameloblastoma exhibits five tumor subpopulations varying with respect to immune response(IR),bone remodeling(BR),tooth development(TD),epithelial development(ED),and cell cycle(CC)signatures.Of note,we found that CC ameloblastoma cells were endowed with stemness and contributed to tumor recurrence,which was dominated by the EZH2-mediated program.Targeting EZH2 effectively eliminated CC ameloblastoma cells and inhibited tumor growth in ameloblastoma patient-derived organoids.These data described the tumor subpopulation and clarified the identity,function,and regulatory mechanism of CC ameloblastoma cells,providing a potential therapeutic target for ameloblastoma.展开更多
Background:As reported,γ-tubulin(TuBG1)is related to the occurrence and development of various types of malignant tumors.However,its role in hepatocellular cancer(HCC)is not clear.The present study was to investigate...Background:As reported,γ-tubulin(TuBG1)is related to the occurrence and development of various types of malignant tumors.However,its role in hepatocellular cancer(HCC)is not clear.The present study was to investigate the relationship between TuBG1 and clinical parameters and survival in HCC patients.Methods:The correlation between TuBG1 and clinical parameters and survival in HCC patients was ex-plored by bioinformatics analysis.Immunohistochemistry was used for the verification.The molecular function of TuBG1 was measured using colony formation,scratch assay,trans-well assay and flow cytometry.Gene set enrichment analysis(GSEA)was used to pick up the enriched pathways,followed by investigating the target pathways using Western blotting.The tumor-immune system interactions and drug bank database(TISIDB)was used to evaluate TuBG1 and immunity.Based on the TuBG1-related immune genes,a prognostic model was constructed and was further validated internally and externally.Results:The bioinformatic analysis found high expressed TuBG1 in HCC tissue,which was confirmed us-ing immunohistochemistry and Western blotting.After silencing the TuBG1 in HCC cell lines,more G1 arrested cells were found,cell proliferation and invasion were inhibited,and apoptosis was promoted.Furthermore,the silence of TuBG1 increased the expressions of Ataxia-Telangiectasia and Rad-3(ATR),phospho-P38 mitogen-activated protein kinase(P-P38MAPK),phospho-P53(P-P53),B-cell lymphoma-2 associated X protein(Bax),cleaved caspase 3 and P21;decreased the expressions of B-cell lymphoma-2(Bcl-2),cyclin D1,cyclin E2,cyclin-dependent kinase 2(CDK2)and CDK4.The correlation analysis of immunohistochemistry and clinical parameters and survival data revealed that TuBG1 was negatively corre-lated with the overall survival.The constructed immune prognosis model could effectively evaluate the prognosis.Conclusions:The increased expression of TuBG1 in HCC is associated with poor prognosis,which might be involved in the occurrence and development of HCC.展开更多
Layered oxide is a promising cathode material for sodium-ion batteries because of its high-capacity,high operating voltage,and simple synthesis.Cycling performance is an important criterion for evaluating the applicat...Layered oxide is a promising cathode material for sodium-ion batteries because of its high-capacity,high operating voltage,and simple synthesis.Cycling performance is an important criterion for evaluating the application prospects of batteries.However,facing challenges,including phase transitions,ambient stability,side reactions,and irreversible anionic oxygen activity,the cycling performance of layered oxide cathode materials still cannot meet the application requirements.Therefore,this review proposes several strategies to address these challenges.First,bulk doping is introduced from three aspects:cationic single doping,anionic single doping,and multi-ion doping.Second,homogeneous surface coating and concentration gradient modification are reviewed.In addition,methods such as mixed structure design,particle engineering,high-entropy material construction,and integrated modification are proposed.Finally,a summary and outlook provide a new horizon for developing and modifying layered oxide cathode materials.展开更多
Effective calcium(Ca)management is crucial for optimizing oil palm cultivation and enhancing crop yield.This study aimed to gain insights into the dynamics of Ca concentration,accumulation,exportation,immobilization,a...Effective calcium(Ca)management is crucial for optimizing oil palm cultivation and enhancing crop yield.This study aimed to gain insights into the dynamics of Ca concentration,accumulation,exportation,immobilization,and recycling in various oil palm organs relative to plant age.The experiment was conducted at the Agropalma enterprise site in the northeastern region of Para State,Brazil,evaluating seven plant age treatments:2,3,4,5,6,7,and 8 years old.Employing a completely randomized design with four replications.The results demonstrated an age-related increase in Ca concentration in petioles,rachis,arrows,male inflorescences,peduncles,and fruits.Furthermore,Ca accumulation exhibited an upward trend in all organs with progressing plant age.Notably,the study revealed an enhanced Ca use efficiency across all plant organs in correlation with the age of oil palm cultivation.These findings underscore the dynamic nutritional demands of oil palm,influencing Ca immobilization,cycling,and export throughout its developmental stages.展开更多
Developing supercapacitors(SCs)with long cycling life and wide operative voltage window is a significant topic in the field of aqueous electrolytes.Although the design of water in salt(WIS)electrolytes has pushed the ...Developing supercapacitors(SCs)with long cycling life and wide operative voltage window is a significant topic in the field of aqueous electrolytes.Although the design of water in salt(WIS)electrolytes has pushed the development of aqueous electrolytes to a new height,the WIS electrolytes with an operative voltage window of up to 2.5 V is still very scarce.Herein,in order to enrich the type of aqueous electrolyte with high operative voltage,tetramethylammonium trifluoromethanesulfonate(TMAOTf)based WIS electrolyte was used as a model to construct WIS based hybrid electrolyte with acetonitrile(ACN)co-solvent and LiTFSI co-solute.In view of the coordination effect of ACN and Lit on free water in TMAOTf based WIS electrolyte,the TMAt-Lit-AWIS electrolyte has the electrochemical stabilization window of up to 3.35 V.Further coupled with the commercial YP-50F electrodes,TMAt-Lit-AWIS based SCs exhibited wide operative voltage window(2.5 V),long cycling life(45,000 cycles)and good low-temperature performance(99.99%capacitance retention after 2000 cycles at20℃).The design of this hybrid electrolyte will enrich the types of aqueous hybrid electrolytes with long cycling life and wide operative voltage window.展开更多
In recent years,the compact development of high-density cities has sparked ongoing interest in healthy urban environments and public well-being.This study examines the relationship between cycling behaviors and the bu...In recent years,the compact development of high-density cities has sparked ongoing interest in healthy urban environments and public well-being.This study examines the relationship between cycling behaviors and the built environment of streets in Tiantongyuan Community,a typical high-density area in Beijing,China.By observing street spaces and summarizing residents’travel modes and behaviors,the study evaluates the impact of street design on cycling habits.In order to reveal the riding behavior characteristics of residents in different time periods and different street spaces,tools such as track recording APPs and the Gopro Motion Camera are employed to collect street view pictures and riding track data comprehensively,analyzing the various travel purposes of residents in Tiantongyuan community and the riding OD activity tracks of the main entrances and exits of the community.Meanwhile,by conducting the questionnaire survey of residents’travel demands and OD data of about:blank,and utilizing geographic information system(GIS)for data visualization,this study further investigates the distribution characteristics of cycling hotspots,cycling paths and cycling space,accurately identifies the cycling life circle of this community based on the spatial and temporal scales,and further puts forward the optimization strategy of the cycling network.Some cycling-friendly street space optimization strategies are suggested to deeply analyze the mechanism of the built environment of street space in high-density communities on the cycling activities and health of urban residents,with a view to provide accurate data support for the renewal of street cycling space.展开更多
Imagine a world where carbon dioxide(CO_(2))emissions that contribute to global warming are not only captured but transformed into something valuable.Scientists have now engineered a new method that could make this vi...Imagine a world where carbon dioxide(CO_(2))emissions that contribute to global warming are not only captured but transformed into something valuable.Scientists have now engineered a new method that could make this vision a reality,offering a new twist on carbon fixation.展开更多
Possenia,a trailblazing newcomer in the cycling industry,proudly announces a groundbreaking achievement:it is Switzerland’s first cycling brand to introduce the bluesign®PRODUCT label,marking an important milest...Possenia,a trailblazing newcomer in the cycling industry,proudly announces a groundbreaking achievement:it is Switzerland’s first cycling brand to introduce the bluesign®PRODUCT label,marking an important milestone in sustainable cycling apparel in Europe.These environmentally conscious,premium cycling essentials are now available on Digitec Galaxus as well as directly through Possenia’s own website.展开更多
Caleb Munyao,a 48-year-old middle-scale farmer from Kenya’s eastern region,understands the importance of water better than most.On his 13-hectare farm,where he grows maize,yellow beans,and mangoes,every drop of water...Caleb Munyao,a 48-year-old middle-scale farmer from Kenya’s eastern region,understands the importance of water better than most.On his 13-hectare farm,where he grows maize,yellow beans,and mangoes,every drop of water is precious.Kenya,like many countries in Africa,faces significant challenges in managing its water resources.The country’s water scarcity issues are exacerbated by climate change,rapid urbanisation,and inconsistent rainfall patterns.展开更多
The dominant annual cycle of sea surface temperature(SST)in the tropical Pacific exhibits an antisymmetric mode,which explains 83.4%total variance,and serves as a background of El Niño-Southern Oscillation(ENSO)....The dominant annual cycle of sea surface temperature(SST)in the tropical Pacific exhibits an antisymmetric mode,which explains 83.4%total variance,and serves as a background of El Niño-Southern Oscillation(ENSO).However,there is no consensus yet on its anomalous impacts on the phase and amplitude of ENSO.Based on data during 1982-2022,results show that anomalies of the antisymmetric mode can affect the evolution of ENSO on the interannual scale via Bjerknes feedback,in which the positive(negative)phase of the antisymmetric mode can strengthen El Niño(La Niña)in boreal winter via an earlier(delayed)seasonal cycle transition and larger(smaller)annual mean.The magnitude of the SST anomalies in the equatorial eastern Pacific can reach more than±0.3◦C,regulated by the changes in the antisymmetric mode based on random sensitivity analysis.Results reveal the spatial pattern of the annual cycle associated with the seasonal phase-locking of ENSO evolution and provide new insight into the impact of the annual cycle of background SST on ENSO,which possibly carries important implications for forecasting ENSO.展开更多
Objectives The purpose of this study is to examine the effects of applying anodal tDCS(2 mA for 20 min)over the scalp from T3(anodal-tDCS)to Fp2(cathodal-tDCS)on the perceptual,physiological and performance responses ...Objectives The purpose of this study is to examine the effects of applying anodal tDCS(2 mA for 20 min)over the scalp from T3(anodal-tDCS)to Fp2(cathodal-tDCS)on the perceptual,physiological and performance responses during maximal incremental and constant-load exercise(CLE)in trained cyclists.Methods Eleven male cyclists performed maximal incremental exercise(MIE)on a cycle ergometer under either tDCS or sham,with power output,heart rate(HR),oxygen uptake(V̇O_(2)),ratings of perceived exertion(RPE)assessed throughout,and blood samples collected before and after MIE.On two separate occasions,nine subjects performed CLE at 62%of the peak power output followed by a 15 km time trial under either tDCS or sham(n=8 for the time trial).Results HR,V̇O_(2),RPE and blood samples were collected at regular intervals.There were no differences between tDCS and sham in any variable during the MIE.tDCS elicited a decreased HR(F_(4,8)=9.232;p=0.016;η_(p)^(2)=0.54),increased V̇O_(2)(F_(4,8)=8.920;p=0.015;η_(p)^(2)=0.50)and increased blood non-esterified fatty acids(F_(6,8)=11.754;p=0.009;η_(p)^(2)=0.60)and glycerol(F_(6,8)=6.603;p=0.037;η_(p)^(2)=0.49)concentrations during the CLE when compared to sham.tDCS also improved 15 km time trial performance by 3.6%(p=0.02;d=0.47)without affecting RPE,HR and blood lactate.Conclusions The application of tDCS over the temporal cortex in trained cyclists improved cycling performance during a self-paced time trial but did not enhance performance during maximal incremental exercise.These results are encouraging and merit further investigation of the ergogenic effects of tDCS in trained athletes.展开更多
基金the National Natural Science Foundation of China(No.U1706221).
文摘Due to the wet-dry cycling in the ocean tidal zone,the supply of dissolved oxygen and salt-containing particles were sufficient,so the corrosion was serious.Pitting corrosion was a common form of localized corrosion.This paper studied the pitting corrosion mechanism of dispersion-strengthened high-strength steel under different wet-dry ratio environments.Electrochemical Impedance Spectroscopy was used to study the changes of corrosion rate and electric double layer structure of the dispersionstrengthened high-strength steel.Scanning electron microscope,Raman spectroscopy,electron probe microanalysis and laser confocal scanning microscope were used to observe the corrosion product morphologies,analyze the corrosion product compositions,analyze the secondary distribution of alloy elements in the corrosion products and analyze the pitting information of the steel after the corrosion products were removed.The results showed that the degree of the steel corrosion was slight when the wetting time was longer,the size and depth of the corrosion pits on the surface were smaller.This was because the environment with longer wetting time made the corrosion products denser.In this environment,the conversion ofγ-FeOOH to Fe3O4 was promoted.In addition,it could also promote the alloying elements to be more concentrated in the rust layer.The above phenomena hindered the further corrosion of the matrix by dissolved oxygen and Cl−in the seawater.
基金Funded by the National Natural Science Foundation of China(No.51878227)。
文摘Microstructures and properties of mortar using ammonium phosphate and potassium phosphate were tested and compared in this case.Moreover,two cementitious additions and two lightweight aggregates,including fly ash,redispersible latex powder,ceramsite sand,and rubber powder,were respectively tried to be applied in magnesium ammonium phosphate cement mortar in order to modify the microstructures and properties.The experimental results show that potassium phosphate is not suitable for magnesium phosphate cement mortar for cold region construction purpose.Although fly ash can bring positive modification in the condition of normal temperature curing,it brings negative effects in the condition of sub-zero temperature curing.Either redispersible latex powder or ceramsite sand can improve the freeze-thaw cycling resistance of magnesium phosphate cement mortar in the conditions of low temperature coupled with freeze-thaw cycling,but only the ceramsite sand can improve both mechanical properties and freeze-thaw cycling resistance.The modification caused by ceramsite sand is mainly due to the exceptional bonding strength between hardened cement paste and the porous surface of ceramsite and the porous structure of ceramsite for the release of frost heave stress.
基金the W.M.Keck Center for Nano-Scale Imaging in the Department of Chemistry and Biochemistry at the University of Arizona(Grant No.RRID:SCR_022884),with funding from the W.M.Keck Foundation Grant.
文摘Approximately 3.44 billion tons of copper mine tailings(MT)were produced globally in 2018 with an increase of 45%from 2010.Significant efforts are being made to manage these tailings through storage facilities,recycling,and reuse in different industries.Currently,a large portion of tailings are managed through the tailing storage facilities(TSF)where these tailings undergo hydro-thermal-mechanical stresses with seasonal cycles which are not comprehensively understood.This study presents an investigative study to evaluate the performance of control and cement-stabilized copper MT under the influence of seasonal cycles,freeze-thaw(F-T)and wet-dry(W-D)conditions,representing the seasonal variability in the cold and arid regions.The control and cement-stabilized MT samples were subjected to a maximum of 12 F-T and 12 W-D cycles and corresponding micro-and-macro behavior was investigated through scanning electron microscope(SEM),volumetric strain(εvT,wet density(r),moisture content loss,and unconfined compressive strength(UCS)tests.The results indicated the vulnerability of Copper MT to 67%and 75%strength loss reaching residual states with 12 F-T and 8 W-D cycles,respectively.Whereas the stabilized MT retained 39%-55%and 16%-34%strength with F-T and W-D cycles,demonstrating increased durability.This research highlights the impact of seasonal cycles and corresponding strength-deformation characteristics of control and stabilized Copper MT in cold and arid regions.
基金We gratefully acknowledge the financial support from the Key Laboratory of Geological Safety of Coastal Urban Underground Space,Ministry of Natural Resources(BHKF2022Y03)Shandong Provincial Colleges and Universities Youth Innovation Technology Support Program,Education Department of Shandong Province(grant number 2023KJ092).
文摘The study focuses on the creep characteristics of significant yellow sandstone for water conservancy, hydropower, and other waterrelated slope excavation unloading rock-graded loading creep characteristics. It conducts a uniaxial graded loading creep test on yellow sandstone under different pre-peak unloading and wetting-drying cycles. The improved nonlinear Nishihara model was obtained by introducing a nonlinear viscous element with an accelerated creep threshold switch. The sensitivity characteristics of the parameters of the improved creep model were analyzed and a nonlinear creep constitutive model was established, considering the unloading-cyclic intrinsic damage induced by water intrusion. The research results show that:(1)With an increase in the unloading point, the porosity of the rock samples initially decreases and then increases. As the number of cyclic water intrusions rises, the porosity of the rock samples gradually increases, reaching a maximum of 9.58% at an unloading point of 70% uniaxial compression stress(0.7 Rc) after five cycles.(2) Total creep deformation increases with the number of cyclic water intrusions;however, with an increase in the unloading ratio, the original samples show an initial decrease, followed by an increase in creep deformation. With a higher unloading ratio and various instances of cyclic water intrusion, the total creep time of the rock samples,compared to the original samples, is reduced by 21.8%and 23.02%. The creep damage mode gradually changes from shear damage to tensile damage.(3) The sensitivity characteristics of the improved creep model parameters show that transient elasticity modulus E1 is affected by the coupling of unloading and cyclic water intrusion. The viscoelastic modulus E2 and viscous coefficient η1 are mainly affected by unloading and cyclic water intrusion.(4) Based on the strain equivalence principle of damage mechanics, the damage treatment of the parameters in the original model is improved to construct a nonlinear creep constitutive model that considers unloading-cyclic water intrusion damage. A parameter inversion and comparison to the traditional Nishihara model reveal an average relative standard deviation of 0.271%,significantly less than 1%, indicating a more accurate nonlinear creep constitutive model. The research results are crucial for analyzing the long-term stability of water-related steep rocky slopes post-excavation and unloading and for preventing and controlling creep-type landslide disasters.
基金This work was supported by the Australian Research Council via Discovery Projects(Nos.DP200103315,DP200103332 and DP230100685)Linkage Projects(No.LP220200920).The authors acknowledge the Microscopy and Microanalysis Facility—John de Laeter Centre,Curtin University for the scientific and technical assistance of material characterizations.L.Zhao and C.Cao would like to acknowledge the PhD scholarship supported by BLACKSTONE Minerals Ltd.
文摘The pursuit of safer and high-performance lithium-ion batteries(LIBs)has triggered extensive research activities on solid-state batteries,while challenges related to the unstable electrode-electrolyte interface hinder their practical implementation.Polymer has been used extensively to improve the cathode-electrolyte interface in garnet-based all-solid-state LIBs(ASSLBs),while it introduces new concerns about thermal stability.In this study,we propose the incorporation of a multi-functional flame-retardant triphenyl phos-phate additive into poly(ethylene oxide),acting as a thin buffer layer between LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)cathode and garnet electro-lyte.Through electrochemical stability tests,cycling performance evaluations,interfacial thermal stability analysis and flammability tests,improved thermal stability(capacity retention of 98.5%after 100 cycles at 60℃,and 89.6%after 50 cycles at 80℃)and safety characteristics(safe and stable cycling up to 100℃)are demonstrated.Based on various materials characterizations,the mechanism for the improved thermal stability of the interface is proposed.The results highlight the potential of multi-functional flame-retardant additives to address the challenges associated with the electrode-electrolyte interface in ASSLBs at high temperature.Efficient thermal modification in ASSLBs operating at elevated temperatures is also essential for enabling large-scale energy storage with safety being the primary concern.
文摘心脏磁共振成像(cardiac magnetic resonance,CMR)过程中患者误动、异常幅度的呼吸运动、心律失常会造成CMR图像质量下降,为解决现有的CMR图像增强网络需要人为制作配对数据,且图像增强后部分组织纹理细节丢失的问题,提出了基于空频域特征学习的循环一致性生成对抗网络(cycle-consistent generative adversavial network based on spatial-frequency domain feature learning,SFFL-CycleGAN).研究结果表明,该网络无须人为制作配对数据集,增强后的CMR图像组织纹理细节丰富,在结构相似度(structural similarity,SSIM)和峰值信噪比(peak signal to noise ratio,PSNR)等方面均优于现有的配对训练网络以及原始的CycleGAN网络,图像增强效果好,有效助力病情诊断.
基金supported by Specialty Crops Research Initiative Award 2022-51181-38325 from the USDA National Institute of Food and Agriculture and Hatch Projects 1008680 and 1017286.
文摘Plastic mulches have become an essential component of modern agriculture since their introduction in the 1950s.However,disposal of plastic mulches poses serious environmental challenges as plastics that are not considered biodegradable or compostable can take several hundred years to degrade.Each year in the United States,only 9%of overall plastic waste is recycled while 79%is accumulated in landfills or the natural environment.Recycling of plastic mulch is especially constrained due to the contamination that results from their use in farming.Currently,recovered mulches are reported to have 30%–80%surface contamination,primarily from soil and plant debris.Plastic mulch waste is concentrated in areas where they are used and can provide logistical opportunities to the plastic recycling industries.Plastic recycling includes mechanical,advanced(chemical and thermal),and biological methods,that may all be used for polyethylene(PE).Most plastic is recycled using the mechanical method,while advanced and biological methods are promising but face significant financial and technical challenges.For all recycling methods,strategies are needed for managing surface contamination to realize the recycling potential of plastic mulch.
文摘In January 2018,construction wrapped on Salesforce Tower(Fig.1),a 61-story office building that now dominates the skyline of San Francisco,CA,USA.In addition to being the tallest building in the city,Salesforce Tower is the largest structure in the world with an onsite water recycling system.Built by the Australian com-pany Aquacell(Milton,NSW,Australia),the system cleans 113 m^(3)of sewage,sink,shower,and other wastewater each day for use in irrigation and flushing toilets,saving an estimated 35000 m?of water anmually[1].The building is just one of dozens in San Fran-cisco outitted with their own water recycling systems,thanks to a city mandate enacted in 2015[1].
基金supported by the National Natural Science Foundation of China(82141112)Guangdong Financial Fund for High-Caliber Hospital Construction(174-2018-XMZC-0001-03-0125/D-14)C.W.and the Clinical Research Program of 9th People’s Hospital,Shanghai Jiao Tong University School of Medicine(JYLJ202112).
文摘Ameloblastoma is a benign tumor characterized by locally invasive phenotypes,leading to facial bone destruction and a high recurrence rate.However,the mechanisms governing tumor initiation and recurrence are poorly understood.Here,we uncovered cellular landscapes and mechanisms that underlie tumor recurrence in ameloblastoma at single-cell resolution.Our results revealed that ameloblastoma exhibits five tumor subpopulations varying with respect to immune response(IR),bone remodeling(BR),tooth development(TD),epithelial development(ED),and cell cycle(CC)signatures.Of note,we found that CC ameloblastoma cells were endowed with stemness and contributed to tumor recurrence,which was dominated by the EZH2-mediated program.Targeting EZH2 effectively eliminated CC ameloblastoma cells and inhibited tumor growth in ameloblastoma patient-derived organoids.These data described the tumor subpopulation and clarified the identity,function,and regulatory mechanism of CC ameloblastoma cells,providing a potential therapeutic target for ameloblastoma.
基金This work was supported by grants from the National Natural Science Foundation of China(52072005 and 51872279).
文摘Background:As reported,γ-tubulin(TuBG1)is related to the occurrence and development of various types of malignant tumors.However,its role in hepatocellular cancer(HCC)is not clear.The present study was to investigate the relationship between TuBG1 and clinical parameters and survival in HCC patients.Methods:The correlation between TuBG1 and clinical parameters and survival in HCC patients was ex-plored by bioinformatics analysis.Immunohistochemistry was used for the verification.The molecular function of TuBG1 was measured using colony formation,scratch assay,trans-well assay and flow cytometry.Gene set enrichment analysis(GSEA)was used to pick up the enriched pathways,followed by investigating the target pathways using Western blotting.The tumor-immune system interactions and drug bank database(TISIDB)was used to evaluate TuBG1 and immunity.Based on the TuBG1-related immune genes,a prognostic model was constructed and was further validated internally and externally.Results:The bioinformatic analysis found high expressed TuBG1 in HCC tissue,which was confirmed us-ing immunohistochemistry and Western blotting.After silencing the TuBG1 in HCC cell lines,more G1 arrested cells were found,cell proliferation and invasion were inhibited,and apoptosis was promoted.Furthermore,the silence of TuBG1 increased the expressions of Ataxia-Telangiectasia and Rad-3(ATR),phospho-P38 mitogen-activated protein kinase(P-P38MAPK),phospho-P53(P-P53),B-cell lymphoma-2 associated X protein(Bax),cleaved caspase 3 and P21;decreased the expressions of B-cell lymphoma-2(Bcl-2),cyclin D1,cyclin E2,cyclin-dependent kinase 2(CDK2)and CDK4.The correlation analysis of immunohistochemistry and clinical parameters and survival data revealed that TuBG1 was negatively corre-lated with the overall survival.The constructed immune prognosis model could effectively evaluate the prognosis.Conclusions:The increased expression of TuBG1 in HCC is associated with poor prognosis,which might be involved in the occurrence and development of HCC.
基金the Fundamental Research Funds for the Central Universities,China(No.06500177)the National Natural Science Foundation of China Joint Fund Project(No.U1764255)。
文摘Layered oxide is a promising cathode material for sodium-ion batteries because of its high-capacity,high operating voltage,and simple synthesis.Cycling performance is an important criterion for evaluating the application prospects of batteries.However,facing challenges,including phase transitions,ambient stability,side reactions,and irreversible anionic oxygen activity,the cycling performance of layered oxide cathode materials still cannot meet the application requirements.Therefore,this review proposes several strategies to address these challenges.First,bulk doping is introduced from three aspects:cationic single doping,anionic single doping,and multi-ion doping.Second,homogeneous surface coating and concentration gradient modification are reviewed.In addition,methods such as mixed structure design,particle engineering,high-entropy material construction,and integrated modification are proposed.Finally,a summary and outlook provide a new horizon for developing and modifying layered oxide cathode materials.
文摘Effective calcium(Ca)management is crucial for optimizing oil palm cultivation and enhancing crop yield.This study aimed to gain insights into the dynamics of Ca concentration,accumulation,exportation,immobilization,and recycling in various oil palm organs relative to plant age.The experiment was conducted at the Agropalma enterprise site in the northeastern region of Para State,Brazil,evaluating seven plant age treatments:2,3,4,5,6,7,and 8 years old.Employing a completely randomized design with four replications.The results demonstrated an age-related increase in Ca concentration in petioles,rachis,arrows,male inflorescences,peduncles,and fruits.Furthermore,Ca accumulation exhibited an upward trend in all organs with progressing plant age.Notably,the study revealed an enhanced Ca use efficiency across all plant organs in correlation with the age of oil palm cultivation.These findings underscore the dynamic nutritional demands of oil palm,influencing Ca immobilization,cycling,and export throughout its developmental stages.
基金supported by the Longkou City Science and Technology Research and Development Plan(No.2020KJJH061).
文摘Developing supercapacitors(SCs)with long cycling life and wide operative voltage window is a significant topic in the field of aqueous electrolytes.Although the design of water in salt(WIS)electrolytes has pushed the development of aqueous electrolytes to a new height,the WIS electrolytes with an operative voltage window of up to 2.5 V is still very scarce.Herein,in order to enrich the type of aqueous electrolyte with high operative voltage,tetramethylammonium trifluoromethanesulfonate(TMAOTf)based WIS electrolyte was used as a model to construct WIS based hybrid electrolyte with acetonitrile(ACN)co-solvent and LiTFSI co-solute.In view of the coordination effect of ACN and Lit on free water in TMAOTf based WIS electrolyte,the TMAt-Lit-AWIS electrolyte has the electrochemical stabilization window of up to 3.35 V.Further coupled with the commercial YP-50F electrodes,TMAt-Lit-AWIS based SCs exhibited wide operative voltage window(2.5 V),long cycling life(45,000 cycles)and good low-temperature performance(99.99%capacitance retention after 2000 cycles at20℃).The design of this hybrid electrolyte will enrich the types of aqueous hybrid electrolytes with long cycling life and wide operative voltage window.
文摘In recent years,the compact development of high-density cities has sparked ongoing interest in healthy urban environments and public well-being.This study examines the relationship between cycling behaviors and the built environment of streets in Tiantongyuan Community,a typical high-density area in Beijing,China.By observing street spaces and summarizing residents’travel modes and behaviors,the study evaluates the impact of street design on cycling habits.In order to reveal the riding behavior characteristics of residents in different time periods and different street spaces,tools such as track recording APPs and the Gopro Motion Camera are employed to collect street view pictures and riding track data comprehensively,analyzing the various travel purposes of residents in Tiantongyuan community and the riding OD activity tracks of the main entrances and exits of the community.Meanwhile,by conducting the questionnaire survey of residents’travel demands and OD data of about:blank,and utilizing geographic information system(GIS)for data visualization,this study further investigates the distribution characteristics of cycling hotspots,cycling paths and cycling space,accurately identifies the cycling life circle of this community based on the spatial and temporal scales,and further puts forward the optimization strategy of the cycling network.Some cycling-friendly street space optimization strategies are suggested to deeply analyze the mechanism of the built environment of street space in high-density communities on the cycling activities and health of urban residents,with a view to provide accurate data support for the renewal of street cycling space.
文摘Imagine a world where carbon dioxide(CO_(2))emissions that contribute to global warming are not only captured but transformed into something valuable.Scientists have now engineered a new method that could make this vision a reality,offering a new twist on carbon fixation.
文摘Possenia,a trailblazing newcomer in the cycling industry,proudly announces a groundbreaking achievement:it is Switzerland’s first cycling brand to introduce the bluesign®PRODUCT label,marking an important milestone in sustainable cycling apparel in Europe.These environmentally conscious,premium cycling essentials are now available on Digitec Galaxus as well as directly through Possenia’s own website.
文摘Caleb Munyao,a 48-year-old middle-scale farmer from Kenya’s eastern region,understands the importance of water better than most.On his 13-hectare farm,where he grows maize,yellow beans,and mangoes,every drop of water is precious.Kenya,like many countries in Africa,faces significant challenges in managing its water resources.The country’s water scarcity issues are exacerbated by climate change,rapid urbanisation,and inconsistent rainfall patterns.
基金jointly supported by the National Natural Science Foundation of China [grant numbers U2242205 and 41830969]the S&T Development Fund of CAMS [grant number 2023KJ036]the Basic Scientific Research and Operation Foundation of CAMS [grant number 2023Z018]。
文摘The dominant annual cycle of sea surface temperature(SST)in the tropical Pacific exhibits an antisymmetric mode,which explains 83.4%total variance,and serves as a background of El Niño-Southern Oscillation(ENSO).However,there is no consensus yet on its anomalous impacts on the phase and amplitude of ENSO.Based on data during 1982-2022,results show that anomalies of the antisymmetric mode can affect the evolution of ENSO on the interannual scale via Bjerknes feedback,in which the positive(negative)phase of the antisymmetric mode can strengthen El Niño(La Niña)in boreal winter via an earlier(delayed)seasonal cycle transition and larger(smaller)annual mean.The magnitude of the SST anomalies in the equatorial eastern Pacific can reach more than±0.3◦C,regulated by the changes in the antisymmetric mode based on random sensitivity analysis.Results reveal the spatial pattern of the annual cycle associated with the seasonal phase-locking of ENSO evolution and provide new insight into the impact of the annual cycle of background SST on ENSO,which possibly carries important implications for forecasting ENSO.
文摘Objectives The purpose of this study is to examine the effects of applying anodal tDCS(2 mA for 20 min)over the scalp from T3(anodal-tDCS)to Fp2(cathodal-tDCS)on the perceptual,physiological and performance responses during maximal incremental and constant-load exercise(CLE)in trained cyclists.Methods Eleven male cyclists performed maximal incremental exercise(MIE)on a cycle ergometer under either tDCS or sham,with power output,heart rate(HR),oxygen uptake(V̇O_(2)),ratings of perceived exertion(RPE)assessed throughout,and blood samples collected before and after MIE.On two separate occasions,nine subjects performed CLE at 62%of the peak power output followed by a 15 km time trial under either tDCS or sham(n=8 for the time trial).Results HR,V̇O_(2),RPE and blood samples were collected at regular intervals.There were no differences between tDCS and sham in any variable during the MIE.tDCS elicited a decreased HR(F_(4,8)=9.232;p=0.016;η_(p)^(2)=0.54),increased V̇O_(2)(F_(4,8)=8.920;p=0.015;η_(p)^(2)=0.50)and increased blood non-esterified fatty acids(F_(6,8)=11.754;p=0.009;η_(p)^(2)=0.60)and glycerol(F_(6,8)=6.603;p=0.037;η_(p)^(2)=0.49)concentrations during the CLE when compared to sham.tDCS also improved 15 km time trial performance by 3.6%(p=0.02;d=0.47)without affecting RPE,HR and blood lactate.Conclusions The application of tDCS over the temporal cortex in trained cyclists improved cycling performance during a self-paced time trial but did not enhance performance during maximal incremental exercise.These results are encouraging and merit further investigation of the ergogenic effects of tDCS in trained athletes.
