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
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
Background: Reconstruction of Nasal Tip Columella (NTC) subunits is one of the most challenging aspects in functional aesthetic rhinoplasty. Moreover, racial variation for Asian nose rhinoplasty could even demand soph...Background: Reconstruction of Nasal Tip Columella (NTC) subunits is one of the most challenging aspects in functional aesthetic rhinoplasty. Moreover, racial variation for Asian nose rhinoplasty could even demand sophistication of tip and columella strut graft infrastructure enhancement. Various autogenous graft options such as 6th costal cartilage, septal cartilage and conchal cartilage are very commonly considered whilst the 10th costal cartilage is scarcely reported. Objective and Method: The purpose of this manuscript is to illustrate the detailed operative steps to harvest the 10th costal cartilage for infrastructural grafting at NTC subunits by a case illustration. The pros and cons of different cartilage options will be discussed, particularly its application in cleft nose rhinoplasty in Chinese patient. We have adopted the 10th rib as the key option for NTC reconstruction in 11 cases of Chinese cleft secondary rhinoplasty since 2019 and have achieved good and stable results without complications. Conclusion: The 10th costal cartilage is one of the best options in Nasal Tip Columella subunits reconstruction, particularly in complex cleft nose or failure revision aesthetic rhinoplasty cases, due to its safety of harvesting, and the sufficient quality and quantity of grafting materials it provides for simultaneous adjunctive augmentation purpose.展开更多
Root tips are the main components of absorptive fine roots,but their seasonal dynamics and relationship to environmental factors remain unclear due to the difficulties in methodology.In this study,we explored the temp...Root tips are the main components of absorptive fine roots,but their seasonal dynamics and relationship to environmental factors remain unclear due to the difficulties in methodology.In this study,we explored the temporal patterns of root-tip production and mortality in monoculture plantations of five temperate tree species at a common site in northeastern China,and identified the general environmental controls on such processes.We made monthly in-situ assessments of root tip length(RTL)production and mortality in two hardwood and three coniferous species with a minirhizotron(MR)method during the growing seasons of 2008 and 2009.Air temperature,rainfall,soil temperature and water content at 10 cm depth were determined concurrently.RTL production in all species exhibited consistent peaks in summer(June–August)in two growing seasons.RTL mortality showed substantial interannual and interspecific variability,with peaks in autumn and winter in 2008,but various patterns in 2009.RTL production positively correlated with monthly soil and air temperature across all species,and with monthly rainfall in three coniferous species.However,there was no significant correlation between RTL production and soil water content.By contrast,RTL mortality was weakly related to environmental factors,showing positive correlations with soil temperature in Korean spruce,and with rainfall in Korean pine and Korean spruce.Our findings suggest that the seasonal patterns of RTL production are convergent across the five temperate tree species due to the overlapped distribution of heat and rainfall,which can conduce roots to maximizing the acquisition of nutrient resources in the soil.展开更多
Anti-aliasing spectrum analysis is essential for rotor blade condition monitoring based on Blade Tip Timing(BTT).The Multiple Signal Classification(MUSIC)algorithm,which exploits the orthogonality between signal and n...Anti-aliasing spectrum analysis is essential for rotor blade condition monitoring based on Blade Tip Timing(BTT).The Multiple Signal Classification(MUSIC)algorithm,which exploits the orthogonality between signal and noise subspaces,has been successfully applied for this purpose.However,conventional subspace selection methods relying on fixed thresholds are sensitive to variations in large eigenvalues.Furthermore,the complex disturbances during rotor operation and measurement complicate the identification of blade vibration characteristics.To overcome these challenges,this paper proposes Adaptive Subspace Separation(ASS)and Local Spectral Centroid(LSC)methods to improve the adaptability of subspace selection and the stability of frequency identification,respectively.The impacts of overestimating and underestimating the subspace dimensions on MUSIC's performance are derived mathematically.Simulation and experiments demonstrate the effectiveness of proposed approaches:ASS offers more accurate and stable subspace dimension selection and tracking,while LSC reduces the standard deviation of estimated frequencies by 30 percent.展开更多
The fabrication of nanostructures beyond the diffraction limit has been the focus of nanotechnology research.Scanning probe microscopy(SPM)has attracted the attention of researchers for the detection and manufacture o...The fabrication of nanostructures beyond the diffraction limit has been the focus of nanotechnology research.Scanning probe microscopy(SPM)has attracted the attention of researchers for the detection and manufacture of nanostructures.Here,a nanosecond laser irradiated a cantilevered scanning nearfield optical microscopy(SNOM)tip and directly wrote subwavelength nanostructures on Au nano-film,without the assistance of a mask or vacuum atmosphere.This method was stable and reproducible for long-term use.The in situ morphology detection was conducted after the writing process by atomic force microscope(AFM).A feature linewidth of approximately 83.6 nm(<k/6)was confirmed using scanning electron microscopy(SEM).Linewidth of(167.8±6.6)nm was reproduced stably.Theoretical calculations revealed that the elliptical heat distribution under the SNOM tip generated different linewidths when the tip scanned vertically and horizontally.It also interpreted the influential mechanism of single-pulse energy.The simulated linewidths were consistent with the fabricated linewidths.According to the elemental analysis by energy dispersive spectrometer(EDS),the mechanism of this method can be interpreted asmelting of the Au nano-film instead of oxidation.Owing to its high positioning,machining accuracy,and instantaneous energy,this technology is considered convenient and economical for nanostructure fabrication and is proposed to be applied in nanolithography on multiple materials in the future.展开更多
Bulb-type hydro turbines are commonly used in small-to medium-scale hydropower stations due to their compact design and adaptability to low-head conditions.However,long-termoperation often results in wear at the runne...Bulb-type hydro turbines are commonly used in small-to medium-scale hydropower stations due to their compact design and adaptability to low-head conditions.However,long-termoperation often results in wear at the runner rim,increasing tip clearance and triggering leakage flow and cavitation.These effects reduce hydraulic efficiency and accelerate blade surface erosion,posing serious risks to unit safety and operational stability.This study investigates the influence of tip clearance on cavitation performance in a 24 MW prototype bulb turbine.A three-dimensional numericalmodel is developed to simulate various operating conditions with different tip clearance values(3.0,4.5,and 6.0 mm)and cavitation numbers(σ=1.20–1.33).Internal flow characteristics—including pressure distribution,velocity fields,hydraulic efficiency,and pressure pulsation—are analyzed to elucidate the impact of tip clearance on cavitation development.Results show that underσ=1.2 and a 4.5 mm tip clearance,the pressure pulsation amplitude at the blade tip reaches 4870 Pa—approximately 1.5 times higher than that near the hub.At partial flowconditions,turbine efficiency decreases by up to 6.8%compared to the rated condition.Increasing the tip clearance from 1.5 to 6.0 mm expands the low-pressure area near the blade tip by around 32%,significantly intensifying cavitation.Frequency domain analysis reveals dominant pulsation frequencies between 10–20Hz,characterized by blade-passing features and a wave-clipping effect.These findings provide theoretical insight and quantitative evidence to support the optimization of tip clearance design and cavitation mitigation strategies in bulb turbines,aiming to improve both efficiency and operational stability.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Background: Reconstruction of Nasal Tip Columella (NTC) subunits is one of the most challenging aspects in functional aesthetic rhinoplasty. Moreover, racial variation for Asian nose rhinoplasty could even demand sophistication of tip and columella strut graft infrastructure enhancement. Various autogenous graft options such as 6th costal cartilage, septal cartilage and conchal cartilage are very commonly considered whilst the 10th costal cartilage is scarcely reported. Objective and Method: The purpose of this manuscript is to illustrate the detailed operative steps to harvest the 10th costal cartilage for infrastructural grafting at NTC subunits by a case illustration. The pros and cons of different cartilage options will be discussed, particularly its application in cleft nose rhinoplasty in Chinese patient. We have adopted the 10th rib as the key option for NTC reconstruction in 11 cases of Chinese cleft secondary rhinoplasty since 2019 and have achieved good and stable results without complications. Conclusion: The 10th costal cartilage is one of the best options in Nasal Tip Columella subunits reconstruction, particularly in complex cleft nose or failure revision aesthetic rhinoplasty cases, due to its safety of harvesting, and the sufficient quality and quantity of grafting materials it provides for simultaneous adjunctive augmentation purpose.
基金supported by the National Natural Science Foundation of China(32071749)。
文摘Root tips are the main components of absorptive fine roots,but their seasonal dynamics and relationship to environmental factors remain unclear due to the difficulties in methodology.In this study,we explored the temporal patterns of root-tip production and mortality in monoculture plantations of five temperate tree species at a common site in northeastern China,and identified the general environmental controls on such processes.We made monthly in-situ assessments of root tip length(RTL)production and mortality in two hardwood and three coniferous species with a minirhizotron(MR)method during the growing seasons of 2008 and 2009.Air temperature,rainfall,soil temperature and water content at 10 cm depth were determined concurrently.RTL production in all species exhibited consistent peaks in summer(June–August)in two growing seasons.RTL mortality showed substantial interannual and interspecific variability,with peaks in autumn and winter in 2008,but various patterns in 2009.RTL production positively correlated with monthly soil and air temperature across all species,and with monthly rainfall in three coniferous species.However,there was no significant correlation between RTL production and soil water content.By contrast,RTL mortality was weakly related to environmental factors,showing positive correlations with soil temperature in Korean spruce,and with rainfall in Korean pine and Korean spruce.Our findings suggest that the seasonal patterns of RTL production are convergent across the five temperate tree species due to the overlapped distribution of heat and rainfall,which can conduce roots to maximizing the acquisition of nutrient resources in the soil.
基金supported by the National Natural Science Foundation of China(Nos.52405088 and 92360306)the Postdoctoral Fellowship Program of CPSF,China(No.GZC20241446)+2 种基金the Natural Science Basic Research Program of Shaanxi,China(No.2024JC-YBMS-402)the Fundamental Research Funds for the Central Universities,CHD(No.300102254102)the Foundation of Beilin District,China(No.GX2455)。
文摘Anti-aliasing spectrum analysis is essential for rotor blade condition monitoring based on Blade Tip Timing(BTT).The Multiple Signal Classification(MUSIC)algorithm,which exploits the orthogonality between signal and noise subspaces,has been successfully applied for this purpose.However,conventional subspace selection methods relying on fixed thresholds are sensitive to variations in large eigenvalues.Furthermore,the complex disturbances during rotor operation and measurement complicate the identification of blade vibration characteristics.To overcome these challenges,this paper proposes Adaptive Subspace Separation(ASS)and Local Spectral Centroid(LSC)methods to improve the adaptability of subspace selection and the stability of frequency identification,respectively.The impacts of overestimating and underestimating the subspace dimensions on MUSIC's performance are derived mathematically.Simulation and experiments demonstrate the effectiveness of proposed approaches:ASS offers more accurate and stable subspace dimension selection and tracking,while LSC reduces the standard deviation of estimated frequencies by 30 percent.
基金supported by the National Key Research and Development Program of China(2023YFB4605100)the Shaanxi Provincial Key Research and Development Program(2019ZDLGY01-09 and 2021ZDLGY10-02)the State Key Laboratory of Solidification Processing(SKLSP202203).
文摘The fabrication of nanostructures beyond the diffraction limit has been the focus of nanotechnology research.Scanning probe microscopy(SPM)has attracted the attention of researchers for the detection and manufacture of nanostructures.Here,a nanosecond laser irradiated a cantilevered scanning nearfield optical microscopy(SNOM)tip and directly wrote subwavelength nanostructures on Au nano-film,without the assistance of a mask or vacuum atmosphere.This method was stable and reproducible for long-term use.The in situ morphology detection was conducted after the writing process by atomic force microscope(AFM).A feature linewidth of approximately 83.6 nm(<k/6)was confirmed using scanning electron microscopy(SEM).Linewidth of(167.8±6.6)nm was reproduced stably.Theoretical calculations revealed that the elliptical heat distribution under the SNOM tip generated different linewidths when the tip scanned vertically and horizontally.It also interpreted the influential mechanism of single-pulse energy.The simulated linewidths were consistent with the fabricated linewidths.According to the elemental analysis by energy dispersive spectrometer(EDS),the mechanism of this method can be interpreted asmelting of the Au nano-film instead of oxidation.Owing to its high positioning,machining accuracy,and instantaneous energy,this technology is considered convenient and economical for nanostructure fabrication and is proposed to be applied in nanolithography on multiple materials in the future.
基金Funded by the National Natural Science Foundation of China(52066011)Jiuquan Science and Technology Plan Project University-Level Key Project(2024XJKXM03)Foundation of Key Laboratory of Solar Power System(Grant No.2024SPKL03).
文摘Bulb-type hydro turbines are commonly used in small-to medium-scale hydropower stations due to their compact design and adaptability to low-head conditions.However,long-termoperation often results in wear at the runner rim,increasing tip clearance and triggering leakage flow and cavitation.These effects reduce hydraulic efficiency and accelerate blade surface erosion,posing serious risks to unit safety and operational stability.This study investigates the influence of tip clearance on cavitation performance in a 24 MW prototype bulb turbine.A three-dimensional numericalmodel is developed to simulate various operating conditions with different tip clearance values(3.0,4.5,and 6.0 mm)and cavitation numbers(σ=1.20–1.33).Internal flow characteristics—including pressure distribution,velocity fields,hydraulic efficiency,and pressure pulsation—are analyzed to elucidate the impact of tip clearance on cavitation development.Results show that underσ=1.2 and a 4.5 mm tip clearance,the pressure pulsation amplitude at the blade tip reaches 4870 Pa—approximately 1.5 times higher than that near the hub.At partial flowconditions,turbine efficiency decreases by up to 6.8%compared to the rated condition.Increasing the tip clearance from 1.5 to 6.0 mm expands the low-pressure area near the blade tip by around 32%,significantly intensifying cavitation.Frequency domain analysis reveals dominant pulsation frequencies between 10–20Hz,characterized by blade-passing features and a wave-clipping effect.These findings provide theoretical insight and quantitative evidence to support the optimization of tip clearance design and cavitation mitigation strategies in bulb turbines,aiming to improve both efficiency and operational stability.
