In order to further improve the utility of unmanned aerial vehicle(UAV)remote-sensing for quickly and accurately monitoring the growth of winter wheat under film mulching, this study examined the treatments of ridge m...In order to further improve the utility of unmanned aerial vehicle(UAV)remote-sensing for quickly and accurately monitoring the growth of winter wheat under film mulching, this study examined the treatments of ridge mulching,ridge–furrow full mulching, and flat cropping full mulching in winter wheat.Based on the fuzzy comprehensive evaluation (FCE) method, four agronomic parameters (leaf area index, above-ground biomass, plant height, and leaf chlorophyll content) were used to calculate the comprehensive growth evaluation index (CGEI) of the winter wheat, and 14 visible and near-infrared spectral indices were calculated using spectral purification technology to process the remote-sensing image data of winter wheat obtained by multispectral UAV.Four machine learning algorithms, partial least squares, support vector machines, random forests, and artificial neural network networks(ANN), were used to build the winter wheat growth monitoring model under film mulching, and accuracy evaluation and mapping of the spatial and temporal distribution of winter wheat growth status were carried out.The results showed that the CGEI of winter wheat under film mulching constructed using the FCE method could objectively and comprehensively evaluate the crop growth status.The accuracy of remote-sensing inversion of the CGEI based on the ANN model was higher than for the individual agronomic parameters, with a coefficient of determination of 0.75,a root mean square error of 8.40, and a mean absolute value error of 6.53.Spectral purification could eliminate the interference of background effects caused by mulching and soil, effectively improving the accuracy of the remotesensing inversion of winter wheat under film mulching, with the best inversion effect achieved on the ridge–furrow full mulching area after spectral purification.The results of this study provide a theoretical reference for the use of UAV remote-sensing to monitor the growth status of winter wheat with film mulching.展开更多
Metal sulfides are a class of promising anode materials for sodium-ion batteries(SIBs)owing to their high theoretical specific capacity.Nevertheless,the reactant products(polysulfides)could dissolve into electrolyte,s...Metal sulfides are a class of promising anode materials for sodium-ion batteries(SIBs)owing to their high theoretical specific capacity.Nevertheless,the reactant products(polysulfides)could dissolve into electrolyte,shuttle across separator,and react with sodium anode,leading to severe capacity loss and safety concerns.Herein,for the first time,gallium(Ga)-based liquid metal(LM)alloy is incorporated with MoS_(2)nanosheets to work as an anode in SIBs.The electron-rich,ultrahigh electrical conductivity,and self-healing properties of LM endow the heterostructured MoS_(2)-LM with highly improved conductivity and electrode integrity.Moreover,LM is demonstrated to have excellent capability for the adsorption of polysulfides(e.g.,Na_(2)S,Na_(2)S_(6),and S_(8))and subsequent catalytic conversion of Na_(2)S.Consequently,the MoS_(2)-LM electrode exhibits superior ion diffusion kinetics and long cycling performance in SIBs and even in lithium/potassium-ion battery(LIB/PIB)systems,far better than those electrodes with conventional binders(polyvinylidene difluoride(PVDF)and sodium carboxymethyl cellulose(CMC)).This work provides a unique material design concept based on Ga-based liquid metal alloy for metal sulfide anodes in rechargeable battery systems and beyond.展开更多
Vertical-axis wind turbines(VAWTs)have been widely used in urban environments,which contain dust and experience strong turbulence.However,airfoils for VAWTs in urban environments have received considerably less resear...Vertical-axis wind turbines(VAWTs)have been widely used in urban environments,which contain dust and experience strong turbulence.However,airfoils for VAWTs in urban environments have received considerably less research attention than those for horizontal-axis wind turbines(HAWTs).In this study,the sensitivity of a new VAWT airfoil developed at the Lanzhou University of Technology(LUT)to roughness was investigated via a wind tunnel experiment.The results show that the LUT airfoil is less sensitive to roughness at a roughness height of<0.35 mm.Moreover,the drag bucket of the LUT airfoil decreases with increasing roughness height.Furthermore,the loads on the LUT airfoil during dynamic stall were studied at different turbulence intensities using a numerical method at a tip-speed ratio of 2.Before the stall,the turbulence intensity did not considerably affect the normal or tangential force coefficients of the LUT airfoil.However,after the stall,the normal force coefficient varied obviously at low turbulence intensity.Moreover,as the turbulence intensity increased,the normal and tangential force coefficients decreased rapidly,particularly in the downwind region of the VAWT.展开更多
Using the observed data from 184 stations over the Yunnan-Guizhou Plateau （YGP） from 1961 to 2005, the long-term trends in sunshine duration, cloud amount, dry visibility （Vd）, dry extinction, and water vapor over...Using the observed data from 184 stations over the Yunnan-Guizhou Plateau （YGP） from 1961 to 2005, the long-term trends in sunshine duration, cloud amount, dry visibility （Vd）, dry extinction, and water vapor over the YGP are analyzed. The results show that 85% of the stations recorded shortening annual sunshine duration, with the decrease rates between -12.2 and -173.7 h/10yr. Results of Mann-Kendall tests indicate that, among the stations with decreasing sunshine duration, 63.7% of them experienced an abrupt change that started in the 1970s and peaked in the 1980s. This decreasing trend has reversed in the early years of the 21st century. The cloud cover and water vapor content in the mid and lower levels over the YGP had no obvious changes during the study period. The annual averages of Vd declined from 34 km in the 1960s to 27 km at present. The annual mean dry extinction coefficient trended upward, from 0.176 to 0.190, on the YGP from 1980 to 2005. Analyses of cloud cover, water vapor, atmospheric visibility, and dry extinction coefficient revealed that emitted tropospheric aerosols （including air pollutants） resulting from increased energy consumption over the YGP could be a major Factor influencing the reductions of sunshine duration and atmospheric visibility.展开更多
Various metal-based electrocatalysts from nanocrystals,to clusters and single-atoms,have been well-discovered towards high-efficient power devices and electrocatalytic conversion.To accelerate energy transformation ma...Various metal-based electrocatalysts from nanocrystals,to clusters and single-atoms,have been well-discovered towards high-efficient power devices and electrocatalytic conversion.To accelerate energy transformation materials discovery,developing high-throughput DFT calculations and machine-learning techniques is of great necessity.This review comprehensively outlines the latest progress of theory-guided design of advanced energy transformation materials.Especially,we focus on the study of single atoms in various power devices,such as fuel cell(oxygen reduction reaction,ORR;acid oxidation reaction;alcohol oxidation reaction),and other reactions for energy-related electrocatalytic conversion of small molecules,such as H_(2)O_(2)evolution reactions(2e−ORR),water splitting(H_(2)evolution reaction/O_(2)evolution reaction,HER/OER),N2 reduction reaction(NRR),and CO_(2)reduction reactions(CO_(2)RR).Firstly,the electronic structure,interaction mechanism,and reaction activation path are discussed to provide an overall blueprint in electrocatalysis and batteries mentioned above.Thereafter,the experimental synthesis strategies,structural recognition,and electrocatalytic performance for the advanced energy transformation materials are figured out.Finally,some viewpoints into the current issues and future design concept of the advanced energy transformation materials are provided.展开更多
Metal-based electrocatalysts with different sizes(single atoms,nanoclusters,and nanoparticles)show different catalytic behaviors for various electrocatalytic reactions.Regulating the coordination environment of active...Metal-based electrocatalysts with different sizes(single atoms,nanoclusters,and nanoparticles)show different catalytic behaviors for various electrocatalytic reactions.Regulating the coordination environment of active sites with precision to rationally design an efficient electrocatalyst is of great significance for boosting electrocatalytic reactions.This review summarizes the recent process of heterogeneous supported single atoms,nanoclusters,and nanoparticles catalysts in electrocatalytic reactions,respectively,and figures out the construct strategies and design concepts based on their strengths and weaknesses.Specifically,four key factors for enhancing electrocatalytic performance,including electronic structure,coordination environment,support property,and interfacial interactions are proposed to provide an overall comprehension to readers in this field.Finally,some insights into the current challenges and future opportunities of the heterogeneous supported electrocatalysts are provided.展开更多
Supported atomically dispersed metal catalysts(ADMCs)have received enormous attention due to their high atom utilization efficiency,mass activity and excellent selectivity.Single-atom site catalysts(SACs)with monometa...Supported atomically dispersed metal catalysts(ADMCs)have received enormous attention due to their high atom utilization efficiency,mass activity and excellent selectivity.Single-atom site catalysts(SACs)with monometal-center as the quintessential ADMCs have been extensively studied in the catalysis-related fields.Beyond SACs,novel atomically dispersed metal catalysts(NADMCs)with flexible active sites featuring two or more catalytically centers including dual-atom and triple-atom catalysts have drawn ever-increasing attention recently.Owing to the presence of multiple neighboring active sites,NADMCs could exhibit much higher activity and selectivity compared with SACs,especially in those complicated reactions with multi-step intermediates.This review comprehensively outlines the recent exciting advances on the NADMCs with emphasis on the deeper understanding of the synergistic interactions among multiple metal atoms and underlying structure-performance relationships.It starts with the systematical introduction of principal synthetic approaches for NADMCs highlighting the key issues of each fabrication method including the atomically precise control in the design of metal nuclearity,and then the state-of-the-art characterizations for identifying and monitoring the atomic structure of NADMCs are explored.Thereafter,the recent development of NADMCs in energy-related applications is systematically discussed.Finally,we provide some new insights into the remaining challenges and opportunities for the development of NADMCs.展开更多
The exposure to plastic debris and associated pollutants for wildlife is of urgent concern,but little attention has been paid on the transfer of plastic additives from plastic debris to organisms.In the present study,...The exposure to plastic debris and associated pollutants for wildlife is of urgent concern,but little attention has been paid on the transfer of plastic additives from plastic debris to organisms.In the present study,the leaching of incorporated flame retardants (FRs),including polybrominated diphenyl ethers (PBDEs),alternative brominated FRs (AFRs),and phosphate flame retardants (PFRs),from different sizes of recycled acrylonitrile-butadiene-styrene (ABS) polymer were investigated in avian digestive fluids.The impact of co-ingested sediment on the leaching of additive-derived FRs in digestive fluids was also explored.In the recycled ABS,BDE 209 (715 μg/g) and 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE,1766 μg/g) had the highest concentrations among all target FRs.The leaching proportions of FRs were higher in finer sizes of ABS.The leaching proportions of FRs from recycled ABS increased with elevated logKow of FRs.In the tests with coexisted ABS and sediment,hexato deca-BDEs,BTBPE,and decabromodiphenyl ethane (DBDPE) migrated from ABS to sediment,which resulted in the less bioaccessible fractions of these FRs in gut fluids.More lipophilic chemicals tended to be adsorbed by sediment from ABS.The results suggest the migration of additive-derived FRs from plastics to other indigestible materials in digestive fluids.The findings in this study provide insights into the transfer of additive-derived FRs from plastics to birds,and indicate the significant contribution of FR-incorporated plastics to bioaccumulation of highly lipophilic FRs.展开更多
Plants can be infected by multiple pathogens concurrently in natural systems. However,pathogen–pathogen interactions have rarely been studied. In addition to the oomycete Phytophthora sojae, fungi such as Fusarium sp...Plants can be infected by multiple pathogens concurrently in natural systems. However,pathogen–pathogen interactions have rarely been studied. In addition to the oomycete Phytophthora sojae, fungi such as Fusarium spp. also cause soybean root rot. In a 3-year field investigation, we discovered that P. sojae and Fusarium spp. frequently coexisted in diseased soybean roots. Out of 336 P. sojae–soybean–Fusarium combinations,more than 80% aggravated disease. Different Fusarium species all enhanced P. sojae infection when co-inoculated on soybean. Treatment with Fusarium secreted non-proteinaceous metabolites had an effect equal to the direct pathogen coinoculation. By screening a Fusarium graminearum mutant library, we identified Fusarium promoting factor of Phytophthora sojae infection 1(Fpp1),encoding a zinc alcohol dehydrogenase. Fpp1 is functionally conserved in Fusarium and contributes to metabolite-mediated infection promotion, in which vitamin B6(VB6) produced by Fusarium is key. Transcriptional and functional analyses revealed that Fpp1 regulates two VB6 metabolism genes, and VB6 suppresses expression of soybean disease resistance-related genes. These results reveal that co-infection with Fusarium promotes loss of P. sojae resistance in soybean, information that will inform the sustainable use of diseaseresistant crop varieties and provide new strategies to control soybean root rot.展开更多
Background:Corneal refractive surgery has become reliable for correcting refractive errors,but it can induce unintended ocular changes that alter refractive outcomes.This study is to evaluate the unintended changes in...Background:Corneal refractive surgery has become reliable for correcting refractive errors,but it can induce unintended ocular changes that alter refractive outcomes.This study is to evaluate the unintended changes in ocular biometric parameters over a 6-month follow-up period after femtosecond laser-assisted laser in situ keratomileusis(FS-LASIK)and small incision lenticule extraction(SMILE).Methods:156 consecutive myopic patients scheduled for FS-LASIK and SMILE were included in this study.Central corneal thickness(CCT),mean curvature of the corneal posterior surface(K_(pm)),internal anterior chamber depth(IACD)and the length from corneal endothelium to retina(ER)were evaluated before and after surgery over a 6-month period.Results:Both the FS-LASIK and SMILE groups(closely matched at the pre-surgery stage)experienced flatter Kpm,shallower IACD and decreased ER 1 week post-surgery(P<0.01),and these changes were larger in FS-LASIK than in SMILE group.During the 1 week to 6 months follow up period,K_(pm),IACD and ER remained stable unlike CCT which increased significantly(P<0.05),more in the FS-LASIK group.Conclusions:During the follow up,the posterior corneal surface became flatter and shifted posteriorly,the anterior chamber depth and the length from the corneal endothelium to retina decreased significantly compared with the pre-surgery stage.These unintended changes in ocular biometric parameters were greater in patients undergoing FS-LASIK than SMILE.The changes present clear challenges for IOL power calculations and should be considered to avoid affecting the outcome of cataract surgery.展开更多
This study experimentally investigates the impact of a single piezoelectric(PZT)actuator on a turbulent boundary layer from a statistical viewpoint.The working conditions of the actuator include a range of frequencies...This study experimentally investigates the impact of a single piezoelectric(PZT)actuator on a turbulent boundary layer from a statistical viewpoint.The working conditions of the actuator include a range of frequencies and amplitudes.The streamwise velocity signals in the turbulent boundary layer flow are measured downstream of the actuator using a hot-wire anemometer.The mean velocity profiles and other basic parameters are reported.Spectra results obtained by discrete wavelet decomposition indicate that the PZT vibration primarily influences the near-wall region.The turbulent intensities at different scales suggest that the actuator redistributes the near-wall turbulent energy.The skewness and flatness distributions show that the actuator effectively alters the sweep events and reduces intermittency at smaller scales.Moreover,under the impact of the PZT actuator,the symmetry of vibration scales’velocity signals is promoted and the structural composition appears in an orderly manner.Probability distribution function results indicate that perturbation causes the fluctuations in vibration scales and smaller scales with high intensity and low intermittency.Based on the flatness factor,the bursting process is also detected.The vibrations reduce the relative intensities of the burst events,indicating that the streamwise vortices in the buffer layer experience direct interference due to the PZT control.展开更多
The adenoma-carcinoma sequence is a well-accepted roadmap for the development of sporadic colorectal cancer.However,cellular heterogeneity in aberrant epithelial cells limits our understanding of carcinogenesis in col...The adenoma-carcinoma sequence is a well-accepted roadmap for the development of sporadic colorectal cancer.However,cellular heterogeneity in aberrant epithelial cells limits our understanding of carcinogenesis in colorectal tissues.Here,we performed a single-cell RNA sequencing survey of 54,788 cells from patient-matched tissue samples,including blood,normal tissue,para-cancer,polyp,and colorectal cancer.展开更多
Backgroud:To evaluate the symmetry of corneal biomechanical metrics,measured using an ocular response analyzer(ORA)and self-built corneal inflation test platform,in bilateral rabbit corneas and to investigate their re...Backgroud:To evaluate the symmetry of corneal biomechanical metrics,measured using an ocular response analyzer(ORA)and self-built corneal inflation test platform,in bilateral rabbit corneas and to investigate their relationship with physical intraocular pressure(IOPp).Methods:Twenty fresh enucleated eyes from ten rabbits were used for ex vivo whole ocular globe inflation.IOP was increased from 7.5 to 37.5 mmHg with 7.5 mmHg steps and biomechanical metrics were acquired using the ORA.At least 3 examinations were performed at each pressure stage.Two biomechanical metrics,corneal hysteresis(CH)and corneal resistance factor(CRF)were recorded and analyzed as a function of IOPp.Corneal specimens were then excised from the intact ocular globe and tested under inflation conditions up to 45.7 mmHg posterior pressure.The experimental pressure-deformation data was analyzed using an inverse modeling procedure to derive the stress-strain behavior of the cornea.Results:A comparison of corneal shape parameters showed no statistically significant difference(P>0.05)between bilateral eyes.Similarly,there were no statistically significant differences in values of CH,CRF and corneal stiffness(as measured by the tangent modulus,Et)between bilateral eyes(CH:F=0.94,P=0.54;CRF:F=4.42,P=0.35;Et:F=3.15,P=0.12)at different pressure levels.IOPp was highly correlated with CRF while the relationship with CH was less pronounced.Conclusions:An obvious interocular symmetry in biomechanical metrics is found in this research.IOP has been shown to have important influences on the value of CRF provided by ORA.展开更多
Plant pattern recognition receptors(PRRs)are sentinels at the cell surface sensing microbial invasion and activating innate immune responses.During infection,certain microbial apoplastic effectors can be recognized by...Plant pattern recognition receptors(PRRs)are sentinels at the cell surface sensing microbial invasion and activating innate immune responses.During infection,certain microbial apoplastic effectors can be recognized by plant PRRs,culminating in immune responses accompanied by cell death.However,the intricated relationships between the activation of immune responses and cell death are unclear.Here,we studied the glycoside hydrolase family12(GH12)protein,Ps109281,secreted by Phytophthora sojae into the plant apoplast during infection.Ps109281 exhibits xyloglucanase activity,and promotes P.sojae infection in a manner dependent on the enzyme activity.Ps109281 is recognized by the membranelocalized receptor-like protein RXEG1 and triggers immune responses in various plant species.Unlike other characterized GH12 members,Ps109281 fails to trigger cell death in plants.The loss of cell death induction activity is closely linked to a sequence polymorphism at the Nterminus.This sequence polymorphism does not affect the in planta interaction of Ps109281 with the recognition receptor RXEG1,indicating that cell death and immune response activation are determined using different regions of the GH12 proteins.Such GH12 protein also exists in other Phytophthora and fungal pathogens.Taken together,these results unravel the evolution of effector sequences underpinning different immune outputs.展开更多
Fatty acid b-oxidation is critical for fatty acid degradation and cellular development.In the rice blast fungus Magnaporthe oryzae,fatty acid b-oxidation is reported to be important mainly for turgor generation in the...Fatty acid b-oxidation is critical for fatty acid degradation and cellular development.In the rice blast fungus Magnaporthe oryzae,fatty acid b-oxidation is reported to be important mainly for turgor generation in the appressorium.However,the role of fatty acid b-oxidation during invasive hyphal growth is rarely documented.We demonstrated that blocking peroxisomal fatty acid b-oxidation impaired lipid droplet(LD)degradation and infectious growth of M.oryzae.We found that the key regulator of pathogenesis,MoMsn2,which we identified previously,is involved in fatty acid b-oxidation by targeting MoDCI1(encoding dienoyl-coenzyme A[CoA]isomerase),which is also important for LD degradation and infectious growth.Cytological observations revealed that MoMsn2 accumulated from the cytosol to the nucleus during early infection or upon treatment with oleate.We determined that the low-density lipoprotein receptor-related protein MoLrp1,which is also involved in fatty acid b-oxidation and infectious growth,plays a critical role in the accumulation of MoMsn2 from the cytosol to the nucleus by activating the cyclic AMP signaling pathway.Our results provide new insights into the importance of fatty acid oxidation during invasive hyphal growth,which is modulated by MoMsn2 and its related signaling pathways in M.oryzae.展开更多
The mitotic exit network(MEN)pathway is a vital kinase cascade regulating the timely and correct progress of cell division.In the rice blast fungus Magnaporthe oryzae,the MEN pathway,consisting of conserved protein ki...The mitotic exit network(MEN)pathway is a vital kinase cascade regulating the timely and correct progress of cell division.In the rice blast fungus Magnaporthe oryzae,the MEN pathway,consisting of conserved protein kinases MoSep1 and MoMob1-MoDbf2,is important in the development and pathogenicity of the fungus.We found that deletion of MoSEP1 affects the phosphorylation of MoMob1,but not MoDbf2,in contrast to what was found in the buddy yeast Saccharomyces cerevisiae,and verified this finding by in vitro phosphorylation assay and mass spectrom-etry(MS)analysis.We also found that S43 residue is the critical phosphor-site of MoMob1 by MoSep1,and proved that MoSep1-dependent MoMob1 phosphorylation is essential for cell division during the development of M.oryzae.We further provided evidence demonstrating that MoSep1 phosphorylates MoMob1 to maintain the cell cycle during vegetative growth and infection.Taken together,our results revealed that the MEN pathway has both distinct and conservative functions in regulating the cell cycle during the development and pathogenesis of M.oryzae.展开更多
Fitting of corneal topography data to analytical surfaces has been necessary in many clinical and experimental applications,yet absolute superiority of fitting methods was still unclear,and their overfitting risks wer...Fitting of corneal topography data to analytical surfaces has been necessary in many clinical and experimental applications,yet absolute superiority of fitting methods was still unclear,and their overfitting risks were not well studied.This study aimed to evaluate the accuracy and reliability of orthogonal polynomials as fitting routines to represent corneal topography.Four orthogonal polynomials,namely,Zernike polynomials(ZPs),pseudo-Zernike polynomials(PZPs),Gaussian-Hermite polynomials(GHPs)and Orthogonal Fourier-Mellin polynomials(OFMPs),were employed to fit anterior and posterior corneal topographies collected from 200 healthy and 174 keratoconic eyes using Pentacam topographer.The fitting performance of these polynomials were compared,and the potential overfitting risks were assessed through a prediction exercise.The results showed that,except for low orders,the fitting performance differed little among polynomials with orders10 regarding surface reconstruction(RMSEs~0.3μm).Anterior surfaces of normal corneas were fitted more efficiently,followed by those of keratoconic corneas,then posterior corneal surfaces.The results,however,revealed an alarming fact that all polynomials tended to overfit the data beyond certain orders.GHPs,closely followed by ZPs,were the most robust in predicting unmeasured surface locations;while PZPs and especially OFMPs overfitted the surfaces drastically.Order 10 appeared to be optimum for corneal surfaces with 10-mm diameter,ensuring accurate reconstruction and avoiding overfitting.The optimum order however varied with topography diameters and data resolutions.The study concluded that continuing to use ZPs as fitting routine for most topography maps,or using GHPs instead,remains a good choice.Choosing polynomial orders close to the topography diameters(millimeters)is generally suggested to ensure both reconstruction accuracy and prediction reliability and avoid overfitting for both normal and complex(e.g.,keratoconic)corneal surfaces.展开更多
基金This study was funded by the National Key R&D Program of China(2021YFD1900700)the National Natural Science Foundation of China(51909221)the China Postdoctoral Science Foundation(2020T130541 and 2019M650277).
文摘In order to further improve the utility of unmanned aerial vehicle(UAV)remote-sensing for quickly and accurately monitoring the growth of winter wheat under film mulching, this study examined the treatments of ridge mulching,ridge–furrow full mulching, and flat cropping full mulching in winter wheat.Based on the fuzzy comprehensive evaluation (FCE) method, four agronomic parameters (leaf area index, above-ground biomass, plant height, and leaf chlorophyll content) were used to calculate the comprehensive growth evaluation index (CGEI) of the winter wheat, and 14 visible and near-infrared spectral indices were calculated using spectral purification technology to process the remote-sensing image data of winter wheat obtained by multispectral UAV.Four machine learning algorithms, partial least squares, support vector machines, random forests, and artificial neural network networks(ANN), were used to build the winter wheat growth monitoring model under film mulching, and accuracy evaluation and mapping of the spatial and temporal distribution of winter wheat growth status were carried out.The results showed that the CGEI of winter wheat under film mulching constructed using the FCE method could objectively and comprehensively evaluate the crop growth status.The accuracy of remote-sensing inversion of the CGEI based on the ANN model was higher than for the individual agronomic parameters, with a coefficient of determination of 0.75,a root mean square error of 8.40, and a mean absolute value error of 6.53.Spectral purification could eliminate the interference of background effects caused by mulching and soil, effectively improving the accuracy of the remotesensing inversion of winter wheat under film mulching, with the best inversion effect achieved on the ridge–furrow full mulching area after spectral purification.The results of this study provide a theoretical reference for the use of UAV remote-sensing to monitor the growth status of winter wheat with film mulching.
基金the financial support from the Australian Research Council (ARC) through Future Fellowship (FT210100298)DECRA Fellowship (DE230101068)+2 种基金Discovery Project (DP230100198 and DP210102215)Linkage Projects (LP220100088 and LP180100722)partially supported by AIIM FOR GOLD Grant (2017, 2018)
文摘Metal sulfides are a class of promising anode materials for sodium-ion batteries(SIBs)owing to their high theoretical specific capacity.Nevertheless,the reactant products(polysulfides)could dissolve into electrolyte,shuttle across separator,and react with sodium anode,leading to severe capacity loss and safety concerns.Herein,for the first time,gallium(Ga)-based liquid metal(LM)alloy is incorporated with MoS_(2)nanosheets to work as an anode in SIBs.The electron-rich,ultrahigh electrical conductivity,and self-healing properties of LM endow the heterostructured MoS_(2)-LM with highly improved conductivity and electrode integrity.Moreover,LM is demonstrated to have excellent capability for the adsorption of polysulfides(e.g.,Na_(2)S,Na_(2)S_(6),and S_(8))and subsequent catalytic conversion of Na_(2)S.Consequently,the MoS_(2)-LM electrode exhibits superior ion diffusion kinetics and long cycling performance in SIBs and even in lithium/potassium-ion battery(LIB/PIB)systems,far better than those electrodes with conventional binders(polyvinylidene difluoride(PVDF)and sodium carboxymethyl cellulose(CMC)).This work provides a unique material design concept based on Ga-based liquid metal alloy for metal sulfide anodes in rechargeable battery systems and beyond.
基金This work was supported by the Natural Science Foundation of GANSU(grant 1508RJYA098)National Natural Science Foundation of China(grants 51766009,51761135012,11872248)+1 种基金National Basic Research Program of China(grant 2014CB046201)The authors also thank the people who provided many good suggestions for this paper,and Northwestern Polytechnical University for providing the experimental instruments and wind tunnel.
文摘Vertical-axis wind turbines(VAWTs)have been widely used in urban environments,which contain dust and experience strong turbulence.However,airfoils for VAWTs in urban environments have received considerably less research attention than those for horizontal-axis wind turbines(HAWTs).In this study,the sensitivity of a new VAWT airfoil developed at the Lanzhou University of Technology(LUT)to roughness was investigated via a wind tunnel experiment.The results show that the LUT airfoil is less sensitive to roughness at a roughness height of<0.35 mm.Moreover,the drag bucket of the LUT airfoil decreases with increasing roughness height.Furthermore,the loads on the LUT airfoil during dynamic stall were studied at different turbulence intensities using a numerical method at a tip-speed ratio of 2.Before the stall,the turbulence intensity did not considerably affect the normal or tangential force coefficients of the LUT airfoil.However,after the stall,the normal force coefficient varied obviously at low turbulence intensity.Moreover,as the turbulence intensity increased,the normal and tangential force coefficients decreased rapidly,particularly in the downwind region of the VAWT.
基金funded by the National Natural Science Foundation of China (NSFC) (Grant No. 40965009)the Guizhou Provincial Meteorological Bureau Key Laboratory Programme (No. KF200906)
文摘Using the observed data from 184 stations over the Yunnan-Guizhou Plateau （YGP） from 1961 to 2005, the long-term trends in sunshine duration, cloud amount, dry visibility （Vd）, dry extinction, and water vapor over the YGP are analyzed. The results show that 85% of the stations recorded shortening annual sunshine duration, with the decrease rates between -12.2 and -173.7 h/10yr. Results of Mann-Kendall tests indicate that, among the stations with decreasing sunshine duration, 63.7% of them experienced an abrupt change that started in the 1970s and peaked in the 1980s. This decreasing trend has reversed in the early years of the 21st century. The cloud cover and water vapor content in the mid and lower levels over the YGP had no obvious changes during the study period. The annual averages of Vd declined from 34 km in the 1960s to 27 km at present. The annual mean dry extinction coefficient trended upward, from 0.176 to 0.190, on the YGP from 1980 to 2005. Analyses of cloud cover, water vapor, atmospheric visibility, and dry extinction coefficient revealed that emitted tropospheric aerosols （including air pollutants） resulting from increased energy consumption over the YGP could be a major Factor influencing the reductions of sunshine duration and atmospheric visibility.
基金supported by the National Key R&D Program of China(2018YFA0702003)the National Natural Science Foundation of China(21890383,21871159)+1 种基金the Science and Technology Key Project of Guangdong Province of China(2020B010188002)the China Postdoctoral Science Foundation(2021M691834).
文摘Various metal-based electrocatalysts from nanocrystals,to clusters and single-atoms,have been well-discovered towards high-efficient power devices and electrocatalytic conversion.To accelerate energy transformation materials discovery,developing high-throughput DFT calculations and machine-learning techniques is of great necessity.This review comprehensively outlines the latest progress of theory-guided design of advanced energy transformation materials.Especially,we focus on the study of single atoms in various power devices,such as fuel cell(oxygen reduction reaction,ORR;acid oxidation reaction;alcohol oxidation reaction),and other reactions for energy-related electrocatalytic conversion of small molecules,such as H_(2)O_(2)evolution reactions(2e−ORR),water splitting(H_(2)evolution reaction/O_(2)evolution reaction,HER/OER),N2 reduction reaction(NRR),and CO_(2)reduction reactions(CO_(2)RR).Firstly,the electronic structure,interaction mechanism,and reaction activation path are discussed to provide an overall blueprint in electrocatalysis and batteries mentioned above.Thereafter,the experimental synthesis strategies,structural recognition,and electrocatalytic performance for the advanced energy transformation materials are figured out.Finally,some viewpoints into the current issues and future design concept of the advanced energy transformation materials are provided.
基金the National Key R&D Program of China(No.2018YFA0702003)the National Natural Science Foundation of China(Nos.21890383 and 21871159)+1 种基金the science and Technology Key Project of Guangdong Province of China(No.2020B010188002)the China Postdoctoral Science Foundation(Nos.2021M691757,2021M690086,and 2021TQ0170).
文摘Metal-based electrocatalysts with different sizes(single atoms,nanoclusters,and nanoparticles)show different catalytic behaviors for various electrocatalytic reactions.Regulating the coordination environment of active sites with precision to rationally design an efficient electrocatalyst is of great significance for boosting electrocatalytic reactions.This review summarizes the recent process of heterogeneous supported single atoms,nanoclusters,and nanoparticles catalysts in electrocatalytic reactions,respectively,and figures out the construct strategies and design concepts based on their strengths and weaknesses.Specifically,four key factors for enhancing electrocatalytic performance,including electronic structure,coordination environment,support property,and interfacial interactions are proposed to provide an overall comprehension to readers in this field.Finally,some insights into the current challenges and future opportunities of the heterogeneous supported electrocatalysts are provided.
基金the Beijing Natural Science Foundation(No.2224096)the National Key R&D Program of China(No.2018YFA0702003)+3 种基金the Science and Technology Key Project of Guangdong Province,China(No.2020B010188002)the China Postdoctoral Science Foundation(Nos.2021M690086 and 2021TQ0170)X.B.Z.acknowledges funding support from the Office of China Postdoctoral Council(No.YJ20200277)the“Shuimu Tsinghua Scholar Program"(No.2020SM109)of Tsinghua University,China.
文摘Supported atomically dispersed metal catalysts(ADMCs)have received enormous attention due to their high atom utilization efficiency,mass activity and excellent selectivity.Single-atom site catalysts(SACs)with monometal-center as the quintessential ADMCs have been extensively studied in the catalysis-related fields.Beyond SACs,novel atomically dispersed metal catalysts(NADMCs)with flexible active sites featuring two or more catalytically centers including dual-atom and triple-atom catalysts have drawn ever-increasing attention recently.Owing to the presence of multiple neighboring active sites,NADMCs could exhibit much higher activity and selectivity compared with SACs,especially in those complicated reactions with multi-step intermediates.This review comprehensively outlines the recent exciting advances on the NADMCs with emphasis on the deeper understanding of the synergistic interactions among multiple metal atoms and underlying structure-performance relationships.It starts with the systematical introduction of principal synthetic approaches for NADMCs highlighting the key issues of each fabrication method including the atomically precise control in the design of metal nuclearity,and then the state-of-the-art characterizations for identifying and monitoring the atomic structure of NADMCs are explored.Thereafter,the recent development of NADMCs in energy-related applications is systematically discussed.Finally,we provide some new insights into the remaining challenges and opportunities for the development of NADMCs.
基金supported by the National Natural Science Foundation of China(Nos.41603085 and 41877361)the Natural Science Foundation of Guangdong Province(No.2016A030310440)+2 种基金the Pearl River S&T Nova Program of Guangzhou(No.201806010185)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(No.2017BT01Z134)the Key Research Program of Frontier Sciences,the Chinese Academy of Science(No.QYZDJ-SSW-DQC018)
文摘The exposure to plastic debris and associated pollutants for wildlife is of urgent concern,but little attention has been paid on the transfer of plastic additives from plastic debris to organisms.In the present study,the leaching of incorporated flame retardants (FRs),including polybrominated diphenyl ethers (PBDEs),alternative brominated FRs (AFRs),and phosphate flame retardants (PFRs),from different sizes of recycled acrylonitrile-butadiene-styrene (ABS) polymer were investigated in avian digestive fluids.The impact of co-ingested sediment on the leaching of additive-derived FRs in digestive fluids was also explored.In the recycled ABS,BDE 209 (715 μg/g) and 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE,1766 μg/g) had the highest concentrations among all target FRs.The leaching proportions of FRs were higher in finer sizes of ABS.The leaching proportions of FRs from recycled ABS increased with elevated logKow of FRs.In the tests with coexisted ABS and sediment,hexato deca-BDEs,BTBPE,and decabromodiphenyl ethane (DBDPE) migrated from ABS to sediment,which resulted in the less bioaccessible fractions of these FRs in gut fluids.More lipophilic chemicals tended to be adsorbed by sediment from ABS.The results suggest the migration of additive-derived FRs from plastics to other indigestible materials in digestive fluids.The findings in this study provide insights into the transfer of additive-derived FRs from plastics to birds,and indicate the significant contribution of FR-incorporated plastics to bioaccumulation of highly lipophilic FRs.
基金supported by grants from the National Natural Science Foundation of China (3217237431721004)the China Agriculture Research System (CARS-004-PS14)。
文摘Plants can be infected by multiple pathogens concurrently in natural systems. However,pathogen–pathogen interactions have rarely been studied. In addition to the oomycete Phytophthora sojae, fungi such as Fusarium spp. also cause soybean root rot. In a 3-year field investigation, we discovered that P. sojae and Fusarium spp. frequently coexisted in diseased soybean roots. Out of 336 P. sojae–soybean–Fusarium combinations,more than 80% aggravated disease. Different Fusarium species all enhanced P. sojae infection when co-inoculated on soybean. Treatment with Fusarium secreted non-proteinaceous metabolites had an effect equal to the direct pathogen coinoculation. By screening a Fusarium graminearum mutant library, we identified Fusarium promoting factor of Phytophthora sojae infection 1(Fpp1),encoding a zinc alcohol dehydrogenase. Fpp1 is functionally conserved in Fusarium and contributes to metabolite-mediated infection promotion, in which vitamin B6(VB6) produced by Fusarium is key. Transcriptional and functional analyses revealed that Fpp1 regulates two VB6 metabolism genes, and VB6 suppresses expression of soybean disease resistance-related genes. These results reveal that co-infection with Fusarium promotes loss of P. sojae resistance in soybean, information that will inform the sustainable use of diseaseresistant crop varieties and provide new strategies to control soybean root rot.
基金supported by the National Natural Science Foundation of China(82001924)Zhejiang Provincial Natural Science Foundation of China under Grant(LY20H120001,LQ20A020008)Science and Technology Plan Project of Wenzhou Science and Technology Bureau(Y20190638).
文摘Background:Corneal refractive surgery has become reliable for correcting refractive errors,but it can induce unintended ocular changes that alter refractive outcomes.This study is to evaluate the unintended changes in ocular biometric parameters over a 6-month follow-up period after femtosecond laser-assisted laser in situ keratomileusis(FS-LASIK)and small incision lenticule extraction(SMILE).Methods:156 consecutive myopic patients scheduled for FS-LASIK and SMILE were included in this study.Central corneal thickness(CCT),mean curvature of the corneal posterior surface(K_(pm)),internal anterior chamber depth(IACD)and the length from corneal endothelium to retina(ER)were evaluated before and after surgery over a 6-month period.Results:Both the FS-LASIK and SMILE groups(closely matched at the pre-surgery stage)experienced flatter Kpm,shallower IACD and decreased ER 1 week post-surgery(P<0.01),and these changes were larger in FS-LASIK than in SMILE group.During the 1 week to 6 months follow up period,K_(pm),IACD and ER remained stable unlike CCT which increased significantly(P<0.05),more in the FS-LASIK group.Conclusions:During the follow up,the posterior corneal surface became flatter and shifted posteriorly,the anterior chamber depth and the length from the corneal endothelium to retina decreased significantly compared with the pre-surgery stage.These unintended changes in ocular biometric parameters were greater in patients undergoing FS-LASIK than SMILE.The changes present clear challenges for IOL power calculations and should be considered to avoid affecting the outcome of cataract surgery.
基金National Natural Science Foundation of China(Grants 11732010,11572221,11872272,U1633109,11802195)the National Key R&D Program of the Ministry of Science and Technology,China,on"Green Buildings and Building Industrialization"(Grant 2018YFC0705300).
文摘This study experimentally investigates the impact of a single piezoelectric(PZT)actuator on a turbulent boundary layer from a statistical viewpoint.The working conditions of the actuator include a range of frequencies and amplitudes.The streamwise velocity signals in the turbulent boundary layer flow are measured downstream of the actuator using a hot-wire anemometer.The mean velocity profiles and other basic parameters are reported.Spectra results obtained by discrete wavelet decomposition indicate that the PZT vibration primarily influences the near-wall region.The turbulent intensities at different scales suggest that the actuator redistributes the near-wall turbulent energy.The skewness and flatness distributions show that the actuator effectively alters the sweep events and reduces intermittency at smaller scales.Moreover,under the impact of the PZT actuator,the symmetry of vibration scales’velocity signals is promoted and the structural composition appears in an orderly manner.Probability distribution function results indicate that perturbation causes the fluctuations in vibration scales and smaller scales with high intensity and low intermittency.Based on the flatness factor,the bursting process is also detected.The vibrations reduce the relative intensities of the burst events,indicating that the streamwise vortices in the buffer layer experience direct interference due to the PZT control.
基金This work was funded by the following:National Key Research and Development Program of China(No.2016YFC0906000[2016YFC0906003])National Natural Science Foundation of China(No.81773752,81803574,81902686,and 81801980)+1 种基金Key Program of the Science and Technology Bureau of Sichuan(No.2021YFSY0007)1.3.5 project for disciplines of excellence,West China Hospital,Sichuan University(No.ZYYC20013)。
文摘The adenoma-carcinoma sequence is a well-accepted roadmap for the development of sporadic colorectal cancer.However,cellular heterogeneity in aberrant epithelial cells limits our understanding of carcinogenesis in colorectal tissues.Here,we performed a single-cell RNA sequencing survey of 54,788 cells from patient-matched tissue samples,including blood,normal tissue,para-cancer,polyp,and colorectal cancer.
基金This study was supported by the Science and Technology Plan Project of Wenzhou Science and Technology Bureau(C20120009-04)Science Foundation of the Affiliated Eye Hospital of Wenzhou Medical University(YNCX201312,YNCX201405,YNZD201501)the National Natural Science Foundation of China(81300807).
文摘Backgroud:To evaluate the symmetry of corneal biomechanical metrics,measured using an ocular response analyzer(ORA)and self-built corneal inflation test platform,in bilateral rabbit corneas and to investigate their relationship with physical intraocular pressure(IOPp).Methods:Twenty fresh enucleated eyes from ten rabbits were used for ex vivo whole ocular globe inflation.IOP was increased from 7.5 to 37.5 mmHg with 7.5 mmHg steps and biomechanical metrics were acquired using the ORA.At least 3 examinations were performed at each pressure stage.Two biomechanical metrics,corneal hysteresis(CH)and corneal resistance factor(CRF)were recorded and analyzed as a function of IOPp.Corneal specimens were then excised from the intact ocular globe and tested under inflation conditions up to 45.7 mmHg posterior pressure.The experimental pressure-deformation data was analyzed using an inverse modeling procedure to derive the stress-strain behavior of the cornea.Results:A comparison of corneal shape parameters showed no statistically significant difference(P>0.05)between bilateral eyes.Similarly,there were no statistically significant differences in values of CH,CRF and corneal stiffness(as measured by the tangent modulus,Et)between bilateral eyes(CH:F=0.94,P=0.54;CRF:F=4.42,P=0.35;Et:F=3.15,P=0.12)at different pressure levels.IOPp was highly correlated with CRF while the relationship with CH was less pronounced.Conclusions:An obvious interocular symmetry in biomechanical metrics is found in this research.IOP has been shown to have important influences on the value of CRF provided by ORA.
基金supported by grants from the Natural Science Funds for Distinguished Young Scholars of Jiangsu Province (BK20190027)from the China National Funds (32172423, 31872927 and 31721004)+1 种基金by China Agriculture Research System (CARS-004-PS14)by “the Fundamental Research Funds for the Central Universities” (KJJQ202002 and JCQY201904)
文摘Plant pattern recognition receptors(PRRs)are sentinels at the cell surface sensing microbial invasion and activating innate immune responses.During infection,certain microbial apoplastic effectors can be recognized by plant PRRs,culminating in immune responses accompanied by cell death.However,the intricated relationships between the activation of immune responses and cell death are unclear.Here,we studied the glycoside hydrolase family12(GH12)protein,Ps109281,secreted by Phytophthora sojae into the plant apoplast during infection.Ps109281 exhibits xyloglucanase activity,and promotes P.sojae infection in a manner dependent on the enzyme activity.Ps109281 is recognized by the membranelocalized receptor-like protein RXEG1 and triggers immune responses in various plant species.Unlike other characterized GH12 members,Ps109281 fails to trigger cell death in plants.The loss of cell death induction activity is closely linked to a sequence polymorphism at the Nterminus.This sequence polymorphism does not affect the in planta interaction of Ps109281 with the recognition receptor RXEG1,indicating that cell death and immune response activation are determined using different regions of the GH12 proteins.Such GH12 protein also exists in other Phytophthora and fungal pathogens.Taken together,these results unravel the evolution of effector sequences underpinning different immune outputs.
基金supported by grants from the Natural Science Foundation of China(31871912 and 32061143045 to H.Z.)the Fundamental Research Funds for the Central Universities(KYZ201816 to H.Z.).
文摘Fatty acid b-oxidation is critical for fatty acid degradation and cellular development.In the rice blast fungus Magnaporthe oryzae,fatty acid b-oxidation is reported to be important mainly for turgor generation in the appressorium.However,the role of fatty acid b-oxidation during invasive hyphal growth is rarely documented.We demonstrated that blocking peroxisomal fatty acid b-oxidation impaired lipid droplet(LD)degradation and infectious growth of M.oryzae.We found that the key regulator of pathogenesis,MoMsn2,which we identified previously,is involved in fatty acid b-oxidation by targeting MoDCI1(encoding dienoyl-coenzyme A[CoA]isomerase),which is also important for LD degradation and infectious growth.Cytological observations revealed that MoMsn2 accumulated from the cytosol to the nucleus during early infection or upon treatment with oleate.We determined that the low-density lipoprotein receptor-related protein MoLrp1,which is also involved in fatty acid b-oxidation and infectious growth,plays a critical role in the accumulation of MoMsn2 from the cytosol to the nucleus by activating the cyclic AMP signaling pathway.Our results provide new insights into the importance of fatty acid oxidation during invasive hyphal growth,which is modulated by MoMsn2 and its related signaling pathways in M.oryzae.
基金supported by China National Funds for Innovative Research Groups(Grant No.31721004),NSFC(32030091),NSFC(31972979).
文摘The mitotic exit network(MEN)pathway is a vital kinase cascade regulating the timely and correct progress of cell division.In the rice blast fungus Magnaporthe oryzae,the MEN pathway,consisting of conserved protein kinases MoSep1 and MoMob1-MoDbf2,is important in the development and pathogenicity of the fungus.We found that deletion of MoSEP1 affects the phosphorylation of MoMob1,but not MoDbf2,in contrast to what was found in the buddy yeast Saccharomyces cerevisiae,and verified this finding by in vitro phosphorylation assay and mass spectrom-etry(MS)analysis.We also found that S43 residue is the critical phosphor-site of MoMob1 by MoSep1,and proved that MoSep1-dependent MoMob1 phosphorylation is essential for cell division during the development of M.oryzae.We further provided evidence demonstrating that MoSep1 phosphorylates MoMob1 to maintain the cell cycle during vegetative growth and infection.Taken together,our results revealed that the MEN pathway has both distinct and conservative functions in regulating the cell cycle during the development and pathogenesis of M.oryzae.
基金This work was supported by the National Natural Science Foundation of China[82001924,31771020]the Zhejiang Provincial Natural Science Foundation of China[LY22H180005,LY20H120001,LQ20A020008]+5 种基金the Science and Technology Plan Project of Wenzhou Science and Technology Bureau[Y20180172]the Projects of Medical and Health Technology Development Program in Zhejiang Province[2019RC056]A Project Supported by Scientific Research Fund of Zhejiang Provincial Education Department[Y201839651].The study sponsors had no role in the study designcollection,analysis,and interpretation of datathe writing of the manuscriptthe decision to submit the manuscript for publication.
文摘Fitting of corneal topography data to analytical surfaces has been necessary in many clinical and experimental applications,yet absolute superiority of fitting methods was still unclear,and their overfitting risks were not well studied.This study aimed to evaluate the accuracy and reliability of orthogonal polynomials as fitting routines to represent corneal topography.Four orthogonal polynomials,namely,Zernike polynomials(ZPs),pseudo-Zernike polynomials(PZPs),Gaussian-Hermite polynomials(GHPs)and Orthogonal Fourier-Mellin polynomials(OFMPs),were employed to fit anterior and posterior corneal topographies collected from 200 healthy and 174 keratoconic eyes using Pentacam topographer.The fitting performance of these polynomials were compared,and the potential overfitting risks were assessed through a prediction exercise.The results showed that,except for low orders,the fitting performance differed little among polynomials with orders10 regarding surface reconstruction(RMSEs~0.3μm).Anterior surfaces of normal corneas were fitted more efficiently,followed by those of keratoconic corneas,then posterior corneal surfaces.The results,however,revealed an alarming fact that all polynomials tended to overfit the data beyond certain orders.GHPs,closely followed by ZPs,were the most robust in predicting unmeasured surface locations;while PZPs and especially OFMPs overfitted the surfaces drastically.Order 10 appeared to be optimum for corneal surfaces with 10-mm diameter,ensuring accurate reconstruction and avoiding overfitting.The optimum order however varied with topography diameters and data resolutions.The study concluded that continuing to use ZPs as fitting routine for most topography maps,or using GHPs instead,remains a good choice.Choosing polynomial orders close to the topography diameters(millimeters)is generally suggested to ensure both reconstruction accuracy and prediction reliability and avoid overfitting for both normal and complex(e.g.,keratoconic)corneal surfaces.
