Diplodia tip blight,caused by Diplodia sapinea,is a global pine necrotic disease causing heavy economic losses to the pine industry.Chemical control,its main current management,easily induces pathogen resistance and e...Diplodia tip blight,caused by Diplodia sapinea,is a global pine necrotic disease causing heavy economic losses to the pine industry.Chemical control,its main current management,easily induces pathogen resistance and environmental pollution,which biological control avoids.This study investigated juniper essential oil’s efficacy against the disease on Mongolian Scots pine(Pinus sylvestris var.mongolica)and its induced resistance mechanisms via pot experiments,physiological assays(defense enzyme activities,resistant substances)and metabolomic sequencing(secondary metabolites).Results showed varied efficacy:three foliar sprays of 10μL mL^(-1) oil achieved the best control phenylalanine ammonia-lyase(PAL),polyphenol oxidase(82.9%).The 20μL mL^(-1) treatment significantly increased(PPO)activities,and contents of lignin,flavonoids and total phenolics.Metabolomic analysis showed 326 upregulated and 527 downregulated different metabolites in essential oilinduced and pathogen-inoculated pines,compared to 483 upregulated and 277 downregulated metabolites in noninduced but inoculated pines.The differentially expressed metabolites in treated pines were primarily enriched in pathways related to amino acid metabolism and plant secondary metabolite biosynthesis,with notably increased expression levels of ferulic acid,scopoletin,pipecolic acid,D-proline,and DL-arginine.Therefore,juniper essential oil protects against D.sapinea by inducing systemic acquired resistance in Mongolian Scots pine.In conclusion,juniper essential oil controls D.sapinea by inducing systemic acquired resistance(SAR)in Mongolian Scots pine,clarifying the molecular mechanism and supporting biological control of the disease.展开更多
Glucose molecules are of great significance being one of the most important molecules in metabolic chain.However,due to the small Raman scattering cross-section and weak/non-adsorption on bare metals,accurately obtain...Glucose molecules are of great significance being one of the most important molecules in metabolic chain.However,due to the small Raman scattering cross-section and weak/non-adsorption on bare metals,accurately obtaining their"fingerprint information"remains a huge obstacle.Herein,we developed a tip-enhanced Raman scattering(TERS)technique to address this challenge.Adopting an optical fiber radial vector mode internally illuminates the plasmonic fiber tip to effectively suppress the background noise while generating a strong electric-field enhanced tip hotspot.Furthermore,the tip hotspot approaching the glucose molecules was manipulated via the shear-force feedback to provide more freedom for selecting substrates.Consequently,our TERS technique achieves the visualization of all Raman modes of glucose molecules within spectral window of 400-3200 cm^(-1),which is not achievable through the far-field/surface-enhanced Raman,or the existing TERS techniques.Our TERS technique offers a powerful tool for accurately identifying Raman scattering of molecules,paving the way for biomolecular analysis.展开更多
Postgrouting at the pile tip enhances the performance of cast-in-place piles.To clarify the performance of tip and side resistances,this study analyzed static load test data from two test piles before and after grouti...Postgrouting at the pile tip enhances the performance of cast-in-place piles.To clarify the performance of tip and side resistances,this study analyzed static load test data from two test piles before and after grouting.Mechanisms underlying an improvement in tip resistance and the influence of postgrouting on side resistance were investigated via theoretical analysis.Finally,a design method for tip resistance control via settlement was proposed.Results indicate that the ultimate bearing capacity of piles increases after grouting compared to before,underscoring the importance of tip grouting in gravelly soils and its profound impact on load transmission in pile foundations.Postgrouting at the pile tip enhances the strength as well as initial stiffness of the bearing stratum,ultimately elevating the overall pile foundation-bearing capacity.Additionally,tip grouting helps in strengthening over-all side resistance,especially around the pile tip.The grouting procedure has an impact on the soil’s arching effect at the pile tip;the extent of the arching effect and an increase in horizontal tension close to the pile tip are positively correlated with the effectiveness of grouting reinforcement.The design method for tip resistance control via settlement based on measured data statistics was validated using engineering examples,and the method has a practical reference value.展开更多
Precise control and measurement of nanoparticles using low-power optical tweezers are pivotal for advancing single-particle analysis,nanoscale sensing,and energy transport research.In this work,we present the tipassis...Precise control and measurement of nanoparticles using low-power optical tweezers are pivotal for advancing single-particle analysis,nanoscale sensing,and energy transport research.In this work,we present the tipassisted nanoparticle capture system that simultaneously achieves localized temperature probing and nanoparticle trapping,significantly lowering the required laser power input.Unlike traditional metal-tip plasmonic techniques that predominantly rely on intense electric field gradients,our approach employs a silicon nanotip under resonant laser excitation,uniquely integrating optical forces,thermophoretic forces,and interatomic interactions for stable nanoparticle confinement.This synergistic collaboration mechanism enables approximately a 42%reduction in laser power density compared to conventional bowtie nanoaperture methods.This experimental method achieved direct and simultaneous Raman-based measurements of localized thermal dynamics,providing new insights into nanoscale thermodynamics during optical trapping.Additionally,the silicon nanotip demonstrates reduced thermal transport due to its confined nanoscale geometry,aligning closely with our theoretical predictions.Our integrated strategy of efficient nanoparticle manipulation coupled with precise thermal probing not only enhances overall energy efficiency but also broadens the scope of potential applications in cutting-edge nanoscience and nanotechnology.展开更多
Low-electrode capacitive deionization(FCDI)is an emerging desalination technology with great potential for removal and/or recycling ions from a range of waters.However,it still suffers from inefficient charge transfer...Low-electrode capacitive deionization(FCDI)is an emerging desalination technology with great potential for removal and/or recycling ions from a range of waters.However,it still suffers from inefficient charge transfer and ion transport kinetics due to weak turbulence and low electric intensity in flow electrodes,both restricted by the current collectors.Herein,a new tip-array current collector(designated as T-CC)was developed to replace the conventional planar current collectors,which intensifies both the charge transfer and ion transport significantly.The effects of tip arrays on flow and electric fields were studied by both computational simulations and electrochemical impedance spectroscopy,which revealed the reduction of ion transport barrier,charge transport barrier and internal resistance.With the voltage increased from 1.0 to 1.5 and 2.0 V,the T-CC-based FCDI system(T-FCDI)exhibited average salt removal rates(ASRR)of 0.18,0.50,and 0.89μmol cm^(-2) min^(-1),respectively,which are 1.82,2.65,and 2.48 folds higher than that of the conventional serpentine current collectors,and 1.48,1.67,and 1.49 folds higher than that of the planar current collectors.Meanwhile,with the solid content in flow electrodes increased from 1 to 5 wt%,the ASRR for T-FCDI increased from 0.29 to 0.50μmol cm^(-2) min^(-1),which are 1.70 and 1.67 folds higher than that of the planar current collectors.Additionally,a salt removal efficiency of 99.89%was achieved with T-FCDI and the charge efficiency remained above 95%after 24 h of operation,thus showing its superior long-term stability.展开更多
In an effort to reduce the blade tip clearance leakage in turbine designs, this article aims to numerically investigate the effects of active jet-flow injected from the blade tip platform upon the blade tip clearance ...In an effort to reduce the blade tip clearance leakage in turbine designs, this article aims to numerically investigate the effects of active jet-flow injected from the blade tip platform upon the blade tip clearance flow. A CFD code integrated with dense-correction-based 3D Reynolds-averaged Navier-Stokes equations together with the well-proven Reynolds stress model (RSM) is adopted. The variation of specific heat is taken into consideration. The effects of jet-flow on the tip clearance flow are simulated ...展开更多
This article describes the effects of some factors on the tip clearance flow in axial linear turbine cascades. The measurements of the total pressure loss coefficient are made at the cascade outlets by using a five-ho...This article describes the effects of some factors on the tip clearance flow in axial linear turbine cascades. The measurements of the total pressure loss coefficient are made at the cascade outlets by using a five-hole probe at exit Mach numbers of 0.10, 0.14 and 0.19. At each exit Mach number, experiments are performed at the tip clearance heights of 1.0%, 1.5%, 2.0%, 2.5% and 3.0% of the blade height. The effects of the non-uniform tip clearance height of each blade in the pitchwise direction are also studied. The results show that at a given tip clearance height, generally, total pressure loss rises with exit Mach numbers proportionally. At a fixed exit Mach number, the total pressure loss augments nearly proportionally as the tip clearance height increases. The increased tip clearance heights in the tip regions of two adjacent blades are to be blame for the larger clearance loss of the center blade. Compared to the effects of the tip clearance height, the effects of the exit Mach number and the pitchwise variation of the tip clearance height on the cascade total pressure loss are so less significant to be omitted.展开更多
基金supported by the National Key R&D Program of China(2022YFD1401005).
文摘Diplodia tip blight,caused by Diplodia sapinea,is a global pine necrotic disease causing heavy economic losses to the pine industry.Chemical control,its main current management,easily induces pathogen resistance and environmental pollution,which biological control avoids.This study investigated juniper essential oil’s efficacy against the disease on Mongolian Scots pine(Pinus sylvestris var.mongolica)and its induced resistance mechanisms via pot experiments,physiological assays(defense enzyme activities,resistant substances)and metabolomic sequencing(secondary metabolites).Results showed varied efficacy:three foliar sprays of 10μL mL^(-1) oil achieved the best control phenylalanine ammonia-lyase(PAL),polyphenol oxidase(82.9%).The 20μL mL^(-1) treatment significantly increased(PPO)activities,and contents of lignin,flavonoids and total phenolics.Metabolomic analysis showed 326 upregulated and 527 downregulated different metabolites in essential oilinduced and pathogen-inoculated pines,compared to 483 upregulated and 277 downregulated metabolites in noninduced but inoculated pines.The differentially expressed metabolites in treated pines were primarily enriched in pathways related to amino acid metabolism and plant secondary metabolite biosynthesis,with notably increased expression levels of ferulic acid,scopoletin,pipecolic acid,D-proline,and DL-arginine.Therefore,juniper essential oil protects against D.sapinea by inducing systemic acquired resistance in Mongolian Scots pine.In conclusion,juniper essential oil controls D.sapinea by inducing systemic acquired resistance(SAR)in Mongolian Scots pine,clarifying the molecular mechanism and supporting biological control of the disease.
基金supported by National Natural Science Foundation of China(12374358,91950207)Guangdong Basic and Applied Basic Research Foundation(2024A1515010420).
文摘Glucose molecules are of great significance being one of the most important molecules in metabolic chain.However,due to the small Raman scattering cross-section and weak/non-adsorption on bare metals,accurately obtaining their"fingerprint information"remains a huge obstacle.Herein,we developed a tip-enhanced Raman scattering(TERS)technique to address this challenge.Adopting an optical fiber radial vector mode internally illuminates the plasmonic fiber tip to effectively suppress the background noise while generating a strong electric-field enhanced tip hotspot.Furthermore,the tip hotspot approaching the glucose molecules was manipulated via the shear-force feedback to provide more freedom for selecting substrates.Consequently,our TERS technique achieves the visualization of all Raman modes of glucose molecules within spectral window of 400-3200 cm^(-1),which is not achievable through the far-field/surface-enhanced Raman,or the existing TERS techniques.Our TERS technique offers a powerful tool for accurately identifying Raman scattering of molecules,paving the way for biomolecular analysis.
基金The National Natural Science Foundation of China(No.52008100,52178317)the Natural Science Foundation of Jiangsu Province(No.BK20200400)+1 种基金China Postdoctoral Science Foundation(No.2022M723534)the Natural Science Foundation of Jiangsu Higher Education Institutions of China(No.23KJA560005).
文摘Postgrouting at the pile tip enhances the performance of cast-in-place piles.To clarify the performance of tip and side resistances,this study analyzed static load test data from two test piles before and after grouting.Mechanisms underlying an improvement in tip resistance and the influence of postgrouting on side resistance were investigated via theoretical analysis.Finally,a design method for tip resistance control via settlement was proposed.Results indicate that the ultimate bearing capacity of piles increases after grouting compared to before,underscoring the importance of tip grouting in gravelly soils and its profound impact on load transmission in pile foundations.Postgrouting at the pile tip enhances the strength as well as initial stiffness of the bearing stratum,ultimately elevating the overall pile foundation-bearing capacity.Additionally,tip grouting helps in strengthening over-all side resistance,especially around the pile tip.The grouting procedure has an impact on the soil’s arching effect at the pile tip;the extent of the arching effect and an increase in horizontal tension close to the pile tip are positively correlated with the effectiveness of grouting reinforcement.The design method for tip resistance control via settlement based on measured data statistics was validated using engineering examples,and the method has a practical reference value.
基金supported by the National Natural Science Foundation of China(Grant No.52206107)the National Key R&D Program of China(Grant No.2023YFE0120200)。
文摘Precise control and measurement of nanoparticles using low-power optical tweezers are pivotal for advancing single-particle analysis,nanoscale sensing,and energy transport research.In this work,we present the tipassisted nanoparticle capture system that simultaneously achieves localized temperature probing and nanoparticle trapping,significantly lowering the required laser power input.Unlike traditional metal-tip plasmonic techniques that predominantly rely on intense electric field gradients,our approach employs a silicon nanotip under resonant laser excitation,uniquely integrating optical forces,thermophoretic forces,and interatomic interactions for stable nanoparticle confinement.This synergistic collaboration mechanism enables approximately a 42%reduction in laser power density compared to conventional bowtie nanoaperture methods.This experimental method achieved direct and simultaneous Raman-based measurements of localized thermal dynamics,providing new insights into nanoscale thermodynamics during optical trapping.Additionally,the silicon nanotip demonstrates reduced thermal transport due to its confined nanoscale geometry,aligning closely with our theoretical predictions.Our integrated strategy of efficient nanoparticle manipulation coupled with precise thermal probing not only enhances overall energy efficiency but also broadens the scope of potential applications in cutting-edge nanoscience and nanotechnology.
基金supported by the Shenzhen Science and Technology Program(JCYJ20230808105111022,JCYJ20220818095806013)Natural Science Foundation of Guangdong(2023A1515012267)+1 种基金the National Natural Science Foundation of China(22178223)the Royal Society/NSFC cost share program(IEC\NSFC\223372).
文摘Low-electrode capacitive deionization(FCDI)is an emerging desalination technology with great potential for removal and/or recycling ions from a range of waters.However,it still suffers from inefficient charge transfer and ion transport kinetics due to weak turbulence and low electric intensity in flow electrodes,both restricted by the current collectors.Herein,a new tip-array current collector(designated as T-CC)was developed to replace the conventional planar current collectors,which intensifies both the charge transfer and ion transport significantly.The effects of tip arrays on flow and electric fields were studied by both computational simulations and electrochemical impedance spectroscopy,which revealed the reduction of ion transport barrier,charge transport barrier and internal resistance.With the voltage increased from 1.0 to 1.5 and 2.0 V,the T-CC-based FCDI system(T-FCDI)exhibited average salt removal rates(ASRR)of 0.18,0.50,and 0.89μmol cm^(-2) min^(-1),respectively,which are 1.82,2.65,and 2.48 folds higher than that of the conventional serpentine current collectors,and 1.48,1.67,and 1.49 folds higher than that of the planar current collectors.Meanwhile,with the solid content in flow electrodes increased from 1 to 5 wt%,the ASRR for T-FCDI increased from 0.29 to 0.50μmol cm^(-2) min^(-1),which are 1.70 and 1.67 folds higher than that of the planar current collectors.Additionally,a salt removal efficiency of 99.89%was achieved with T-FCDI and the charge efficiency remained above 95%after 24 h of operation,thus showing its superior long-term stability.
文摘In an effort to reduce the blade tip clearance leakage in turbine designs, this article aims to numerically investigate the effects of active jet-flow injected from the blade tip platform upon the blade tip clearance flow. A CFD code integrated with dense-correction-based 3D Reynolds-averaged Navier-Stokes equations together with the well-proven Reynolds stress model (RSM) is adopted. The variation of specific heat is taken into consideration. The effects of jet-flow on the tip clearance flow are simulated ...
基金National Natural Science Foundation of China (10377011)
文摘This article describes the effects of some factors on the tip clearance flow in axial linear turbine cascades. The measurements of the total pressure loss coefficient are made at the cascade outlets by using a five-hole probe at exit Mach numbers of 0.10, 0.14 and 0.19. At each exit Mach number, experiments are performed at the tip clearance heights of 1.0%, 1.5%, 2.0%, 2.5% and 3.0% of the blade height. The effects of the non-uniform tip clearance height of each blade in the pitchwise direction are also studied. The results show that at a given tip clearance height, generally, total pressure loss rises with exit Mach numbers proportionally. At a fixed exit Mach number, the total pressure loss augments nearly proportionally as the tip clearance height increases. The increased tip clearance heights in the tip regions of two adjacent blades are to be blame for the larger clearance loss of the center blade. Compared to the effects of the tip clearance height, the effects of the exit Mach number and the pitchwise variation of the tip clearance height on the cascade total pressure loss are so less significant to be omitted.
