This research was designed to assess the changes in anthocyanin content in grape skins of Vitis amurensis and to explore m RNA transcriptions of 11 structural genes(PAL,CHS3, CHI1, F3H2, F30 H, F3050 H, DFR, LDOX, UFG...This research was designed to assess the changes in anthocyanin content in grape skins of Vitis amurensis and to explore m RNA transcriptions of 11 structural genes(PAL,CHS3, CHI1, F3H2, F30 H, F3050 H, DFR, LDOX, UFGT,OMT and GST) related to anthocyanin biosynthesis during grape berry development, by the use of HPLC-MS/MS and real-time Q-PCR analysis. Accumulation of anthocyanins began at veraison, continued throughout the later berry development and reached a peak at maturity. Veraison is the time when the berries turn from green to purple. Expression of PAL, CHI1, and LDOX were up-regulated from 2 to4 weeks after flowering(WAF), down-regulated from6 WAF to veraison, whereas DFR was up-regulated at8 WAF, and then up-regulated from veraison to maturity.CHS3, F3050 H, UFGT, GST, and OMT were down-regulated from 2 WAF to veraison, and then up-regulated from veraison to maturity. The transcriptional expressions of the11 structural genes also showed positive correlations with the anthocyanin content from veraison to maturity. Positive correlations were also observed between OMT transcriptional level and the content of methoxyl-anthocyanins, and between F3050 H transcriptional level and the content of delphinidin anthocyanins. F3H2 and F30 H expression was up-regulated at 2 WAF. F3H2 expression was down-regulated from 4 WAF to veraison and then up-regulated again from veraison to maturity. F30 H expression was down-regulated at 4 WAF and then up-regulated again from 6 WAF to maturity. F30 H transcriptional level was correlated positively with the cyanidin anthocyanin concentration from veraison to maturity. These results indicate that the onset of anthocyanin synthesis during berry development coincides with a coordinated increase in the expression of a number of genes in the anthocyanin biosynthetic pathway.展开更多
Cluster removal during the growing season is a widely utilized vineyard management practice aiming to balance crop load to the capacity of the vine to ripen the fruit. Research was undertaken over two growing seasons ...Cluster removal during the growing season is a widely utilized vineyard management practice aiming to balance crop load to the capacity of the vine to ripen the fruit. Research was undertaken over two growing seasons (2008-2009) in Hawke’s Bay, a cool climate region of New Zealand, to establish the influence of different times of crop removal on Merlot vine growth and fruit and wine composition. The test vineyard was high-yielding, to 23 t/ha, and vigorous. A commercial standard of apical cluster thinning to remove 20 clusters per vine from vines with ca 44 clusters in 2008 and ca 47 in 2009, was carried out on uniform vigour, 7yo grafted Merlot vines at nine times between prebloom and six weeks post veraison. The 2009 season was naturally higher yielding. Timing of crop removal had no significant effect on vine vegetative growth in terms of enhanced shoot growth as measured by cane weights at pruning, or canopy leaf density. Time of thinning also had no effect on overall grape yield, cluster weight, and berry weight. There were limited effects on fruit ripeness in one season (2009) at the veraison time of thinning only, with increased Brix and lower TA levels. Berry anthocyanin concentrations were enhanced by cluster thinning in 2008, and more so when undertaken at or soon after veraison. There was however no influence of removal timing on anthocyanin levels and total phenolics in the wines. Grape ripeness, must and wine composition tended to respond more from crop removal at veraison than the other times evaluated. Data suggest that vine response was modified by excessive leafiness and shading.展开更多
Despite being a leading candidate to meet stringent energy targets,lithium(Li) metal batteries(LMBs)face severe challenges at low temperatures such as dramatic increase in impedance,capacity loss and dendrite growth.U...Despite being a leading candidate to meet stringent energy targets,lithium(Li) metal batteries(LMBs)face severe challenges at low temperatures such as dramatic increase in impedance,capacity loss and dendrite growth.Unambiguously fingerprinting rate-limited factors of low-temperature LMBs would encourage targeted approaches to promote performances.Herein,the charge transfer impedance across solid electrolyte interphase(SEI) is identified to restrict battery operation under low temperature,and we propose a facile approach on the basis of ambiently fostering SEI(af-SEI) to facilitate charge transfer.The concept of af-SEI stems from kinetic benefits and structural merits to construct SEI at ambient temperature over low temperature developed SEI that is temporally consuming to achieve steady state and that is structurally defective to incur dendrite growth.The af-SEI allows ionically conductive and morphologically uniform layer on the anode surface,which exhibits a lower resistance and induces an even deposition of Li in the subsequent low temperature battery operation.Armed with af-SEI,the LMBs deliver the improved rate performance and prolonged cycle life when subjected to low temperature cycling.This work unveils the underlying causes that limit low temperature LMB performances,and enlightens the facile test protocols to build up favorable SEI,beyond scope of material and morphology design.展开更多
Surface acoustic wave(SAW)resonators based on lithium tantalate(LT,LiTaO_(3))wafers are crucial elements of mobile communication filters.The use of intrinsic LT wafers typically brings about low fabrication accuracy o...Surface acoustic wave(SAW)resonators based on lithium tantalate(LT,LiTaO_(3))wafers are crucial elements of mobile communication filters.The use of intrinsic LT wafers typically brings about low fabrication accuracy of SAW resonators due to strong UV reflection in the lithography process.This hinders their resonance frequency control seriously in industrial manufacture.LT doping and chemical reduction could be applied to decrease the UV reflection of LT wafers for high lithographic precision.However,conventional methods fail to provide a fast and nondestructive approach to identify the UV performance of standard single-side polished LT wafers for highprecision frequency control.Here,we propose a convenient on-line sensing scheme based on the colorimetry of reduced Fe-doped LT wafers and build up an automatic testing system for industrial applications.The levels of Fe doping and chemical reduction are evaluated by the lightness and color difference of LT-based wafers.The correlation between the wafer visible colorimetry and UV reflection is established to refine the lithography process and specifically manipulate the frequency performance of SAW resonators.Our study provides a powerful tool for the fabrication control of SAW resonators and will inspire more applications on sophisticated devices of mobile communication.展开更多
High-entropy alloy(HEA)-based materials are expected to be promising oxygen electrocatalysts due to their exceptional properties.The electronic structure regulation of HEAs plays a pivotal role in enhancing their elct...High-entropy alloy(HEA)-based materials are expected to be promising oxygen electrocatalysts due to their exceptional properties.The electronic structure regulation of HEAs plays a pivotal role in enhancing their elctrocatalytic ability.Herein,PtFeCoNiMn nanoparticles(NPs)with subtle lattice distortions are constructed on metal-organic framework-derived nitrogen-doped carbon by an ultra-rapid Joule heating process.Thanks to the modulated electronic structure and the inherent cocktail effect of HEAs,the as-synthesized PtFeCoNiMn/NC exhibits superior bifunctional electrocatalytic performance with a positive half-wave potential of 0.863 V vs.reversible hydrogen electrode(RHE)for oxygen reduction reaction and a low overpotential of 357 mV at 10 mA·cm^(-2)for oxygen evolution reaction.The assembled quasi-solid-state zinc-air battery using PtFeCoNiMn/NC as air electrode shows a high peak power density of 192.16 mW·cm^(-2),low charge−discharge voltage gap,and excellent durability over 500 cycles at 5 mA·cm^(-2).This work demonstrates an effective route for rational design of bifunctional nanostructured HEA electrocatalysts with favorable electronic structures,and opens up a fascinating directions for energy storage and conversion,and beyond.展开更多
Data-driven discovery of partial differential equations(PDEs)has recently made tremendous progress,and many canonical PDEs have been discovered successfully for proof of concept.However,determining the most proper PDE...Data-driven discovery of partial differential equations(PDEs)has recently made tremendous progress,and many canonical PDEs have been discovered successfully for proof of concept.However,determining the most proper PDE without prior references remains challenging in terms of practical applications.In this work,a physics-informed information criterion(PIC)is proposed to measure the parsimony and precision of the discovered PDE synthetically.The proposed PIC achieves satisfactory robustness to highly noisy and sparse data on 7 canonical PDEs from different physical scenes,which confirms its ability to handle difficult situations.The PIC is also employed to discover unrevealed macroscale governing equations from microscopic simulation data in an actual physical scene.The results show that the discovered macroscale PDE is precise and parsimonious and satisfies underlying symmetries,which facilitates understanding and simulation of the physical process.The proposition of the PIC enables practical applications of PDE discovery in discovering unrevealed governing equations in broader physical scenes.展开更多
We present an accurate spectral integral method(SIM)for the analyses of scattering from multiple circular perfect electric conductor(PEC)cylinders.It solves the coupled surface integral equations by using the Fourier ...We present an accurate spectral integral method(SIM)for the analyses of scattering from multiple circular perfect electric conductor(PEC)cylinders.It solves the coupled surface integral equations by using the Fourier series and addition theorem to decouple the system.The SIM has exponential convergence so that the error decreases exponentially with the sample density on the surfaces,and requires only about 2–3 points per wavelength(PPW)to reach engineering accuracy defined as higher than 99%accuracy(or with an error smaller than 1%).Numerical results demonstrate that the SIM is much more accurate and efficient than the method of moments(MoM),and thus can be potentially used as the exact radiation boundary condition in the finite element and spectral element methods.展开更多
Low-earth orbit(LEO)satellite networks ignite global wireless connectivity.However,signal outages and co-channel interference limit the coverage in traditional LEO satellite networks where a user is served by a single...Low-earth orbit(LEO)satellite networks ignite global wireless connectivity.However,signal outages and co-channel interference limit the coverage in traditional LEO satellite networks where a user is served by a single satellite.This paper explores the possibility of satellite cooperation in the downlink transmissions.Using tools from stochastic geometry,we model and analyze the downlink coverage of a typical user with satellite cooperation under Nakagami fading channels.Moreover,we derive the joint distance distribution of cooperative LEO satellites to the typical user.Our model incorporates fading channels,cooperation among several satellites,satellites'density and altitude,and co-channel interference.Extensive Monte Carlo simulations are performed to validate analytical results.Simulation and numerical results suggest that coverage with LEO satellites cooperation considerably exceeds coverage without cooperation.Moreover,there are optimal satellite density and satellite altitude that maximize the coverage probability,which gives valuable network design insights.展开更多
Organic chemistry is undergoing a major paradigm shift,moving from a labor-intensive approach to a new era dominated by automation and artificial intelligence(AI).This transformative shift is being driven by technolog...Organic chemistry is undergoing a major paradigm shift,moving from a labor-intensive approach to a new era dominated by automation and artificial intelligence(AI).This transformative shift is being driven by technological advances,the ever-increasing demand for greater research efficiency and accuracy,and the burgeoning growth of interdisciplinary research.AI models,supported by computational power and algorithms,are drastically reshaping synthetic planning and introducing groundbreaking ways to tackle complex molecular synthesis.In addition,autonomous robotic systems are rapidly accelerating the pace of discovery by performing tedious tasks with unprecedented speed and precision.This article examines the multiple opportunities and challenges presented by this paradigm shift and explores its far-reaching implications.It provides valuable insights into the future trajectory of organic chemistry research,which is increasingly defined by the synergistic interaction of automation and AI.展开更多
基金supported by China Agriculture Research System(CARS-30)Jilin Agricultural Science and Technology College seed fund project(2013-903)
文摘This research was designed to assess the changes in anthocyanin content in grape skins of Vitis amurensis and to explore m RNA transcriptions of 11 structural genes(PAL,CHS3, CHI1, F3H2, F30 H, F3050 H, DFR, LDOX, UFGT,OMT and GST) related to anthocyanin biosynthesis during grape berry development, by the use of HPLC-MS/MS and real-time Q-PCR analysis. Accumulation of anthocyanins began at veraison, continued throughout the later berry development and reached a peak at maturity. Veraison is the time when the berries turn from green to purple. Expression of PAL, CHI1, and LDOX were up-regulated from 2 to4 weeks after flowering(WAF), down-regulated from6 WAF to veraison, whereas DFR was up-regulated at8 WAF, and then up-regulated from veraison to maturity.CHS3, F3050 H, UFGT, GST, and OMT were down-regulated from 2 WAF to veraison, and then up-regulated from veraison to maturity. The transcriptional expressions of the11 structural genes also showed positive correlations with the anthocyanin content from veraison to maturity. Positive correlations were also observed between OMT transcriptional level and the content of methoxyl-anthocyanins, and between F3050 H transcriptional level and the content of delphinidin anthocyanins. F3H2 and F30 H expression was up-regulated at 2 WAF. F3H2 expression was down-regulated from 4 WAF to veraison and then up-regulated again from veraison to maturity. F30 H expression was down-regulated at 4 WAF and then up-regulated again from 6 WAF to maturity. F30 H transcriptional level was correlated positively with the cyanidin anthocyanin concentration from veraison to maturity. These results indicate that the onset of anthocyanin synthesis during berry development coincides with a coordinated increase in the expression of a number of genes in the anthocyanin biosynthetic pathway.
文摘Cluster removal during the growing season is a widely utilized vineyard management practice aiming to balance crop load to the capacity of the vine to ripen the fruit. Research was undertaken over two growing seasons (2008-2009) in Hawke’s Bay, a cool climate region of New Zealand, to establish the influence of different times of crop removal on Merlot vine growth and fruit and wine composition. The test vineyard was high-yielding, to 23 t/ha, and vigorous. A commercial standard of apical cluster thinning to remove 20 clusters per vine from vines with ca 44 clusters in 2008 and ca 47 in 2009, was carried out on uniform vigour, 7yo grafted Merlot vines at nine times between prebloom and six weeks post veraison. The 2009 season was naturally higher yielding. Timing of crop removal had no significant effect on vine vegetative growth in terms of enhanced shoot growth as measured by cane weights at pruning, or canopy leaf density. Time of thinning also had no effect on overall grape yield, cluster weight, and berry weight. There were limited effects on fruit ripeness in one season (2009) at the veraison time of thinning only, with increased Brix and lower TA levels. Berry anthocyanin concentrations were enhanced by cluster thinning in 2008, and more so when undertaken at or soon after veraison. There was however no influence of removal timing on anthocyanin levels and total phenolics in the wines. Grape ripeness, must and wine composition tended to respond more from crop removal at veraison than the other times evaluated. Data suggest that vine response was modified by excessive leafiness and shading.
基金supported by the National Natural Science Foundation of China (22379121)Shenzhen Foundation Research Fund granted by the Shenzhen Science and Technology Innovation Committee (JCYJ20220530112812028)+1 种基金Fundamental Research Funds for the Central Universities (G2022KY0606)Zhejiang Province Key Laboratory of Flexible Electronics Open Fund (No. 2023FE005)。
文摘Despite being a leading candidate to meet stringent energy targets,lithium(Li) metal batteries(LMBs)face severe challenges at low temperatures such as dramatic increase in impedance,capacity loss and dendrite growth.Unambiguously fingerprinting rate-limited factors of low-temperature LMBs would encourage targeted approaches to promote performances.Herein,the charge transfer impedance across solid electrolyte interphase(SEI) is identified to restrict battery operation under low temperature,and we propose a facile approach on the basis of ambiently fostering SEI(af-SEI) to facilitate charge transfer.The concept of af-SEI stems from kinetic benefits and structural merits to construct SEI at ambient temperature over low temperature developed SEI that is temporally consuming to achieve steady state and that is structurally defective to incur dendrite growth.The af-SEI allows ionically conductive and morphologically uniform layer on the anode surface,which exhibits a lower resistance and induces an even deposition of Li in the subsequent low temperature battery operation.Armed with af-SEI,the LMBs deliver the improved rate performance and prolonged cycle life when subjected to low temperature cycling.This work unveils the underlying causes that limit low temperature LMB performances,and enlightens the facile test protocols to build up favorable SEI,beyond scope of material and morphology design.
基金Youth Talent Support Program of Fujian Province(Eyas Plan of Fujian Province)National Natural Science Foundation of China(62175205)Natural Science Foundation of Fujian Province(2020J06009)。
文摘Surface acoustic wave(SAW)resonators based on lithium tantalate(LT,LiTaO_(3))wafers are crucial elements of mobile communication filters.The use of intrinsic LT wafers typically brings about low fabrication accuracy of SAW resonators due to strong UV reflection in the lithography process.This hinders their resonance frequency control seriously in industrial manufacture.LT doping and chemical reduction could be applied to decrease the UV reflection of LT wafers for high lithographic precision.However,conventional methods fail to provide a fast and nondestructive approach to identify the UV performance of standard single-side polished LT wafers for highprecision frequency control.Here,we propose a convenient on-line sensing scheme based on the colorimetry of reduced Fe-doped LT wafers and build up an automatic testing system for industrial applications.The levels of Fe doping and chemical reduction are evaluated by the lightness and color difference of LT-based wafers.The correlation between the wafer visible colorimetry and UV reflection is established to refine the lithography process and specifically manipulate the frequency performance of SAW resonators.Our study provides a powerful tool for the fabrication control of SAW resonators and will inspire more applications on sophisticated devices of mobile communication.
基金the financial support of the Shenzhen Key Laboratory of Micro/Nano-Porous Functional Materials(No.ZDSYS20210709112802010)the Shenzhen Science and Technology Innovation Commission(No.GJHZ20220913142610020)+1 种基金Guangdong Grants(No.2021ZT09C064)the National Key Research and Development Program of China(Nos.2022YFA1503900 and 2023YFA1506600)。
文摘High-entropy alloy(HEA)-based materials are expected to be promising oxygen electrocatalysts due to their exceptional properties.The electronic structure regulation of HEAs plays a pivotal role in enhancing their elctrocatalytic ability.Herein,PtFeCoNiMn nanoparticles(NPs)with subtle lattice distortions are constructed on metal-organic framework-derived nitrogen-doped carbon by an ultra-rapid Joule heating process.Thanks to the modulated electronic structure and the inherent cocktail effect of HEAs,the as-synthesized PtFeCoNiMn/NC exhibits superior bifunctional electrocatalytic performance with a positive half-wave potential of 0.863 V vs.reversible hydrogen electrode(RHE)for oxygen reduction reaction and a low overpotential of 357 mV at 10 mA·cm^(-2)for oxygen evolution reaction.The assembled quasi-solid-state zinc-air battery using PtFeCoNiMn/NC as air electrode shows a high peak power density of 192.16 mW·cm^(-2),low charge−discharge voltage gap,and excellent durability over 500 cycles at 5 mA·cm^(-2).This work demonstrates an effective route for rational design of bifunctional nanostructured HEA electrocatalysts with favorable electronic structures,and opens up a fascinating directions for energy storage and conversion,and beyond.
基金the National Center for Applied Mathematics Shenzhen(NCAMS),the Shenzhen Key Laboratory of Natural Gas Hydrates(Grant No.ZDSYS20200421111201738)the SUSTech-Qingdao New Energy Technology Research Institute.
文摘Data-driven discovery of partial differential equations(PDEs)has recently made tremendous progress,and many canonical PDEs have been discovered successfully for proof of concept.However,determining the most proper PDE without prior references remains challenging in terms of practical applications.In this work,a physics-informed information criterion(PIC)is proposed to measure the parsimony and precision of the discovered PDE synthetically.The proposed PIC achieves satisfactory robustness to highly noisy and sparse data on 7 canonical PDEs from different physical scenes,which confirms its ability to handle difficult situations.The PIC is also employed to discover unrevealed macroscale governing equations from microscopic simulation data in an actual physical scene.The results show that the discovered macroscale PDE is precise and parsimonious and satisfies underlying symmetries,which facilitates understanding and simulation of the physical process.The proposition of the PIC enables practical applications of PDE discovery in discovering unrevealed governing equations in broader physical scenes.
文摘We present an accurate spectral integral method(SIM)for the analyses of scattering from multiple circular perfect electric conductor(PEC)cylinders.It solves the coupled surface integral equations by using the Fourier series and addition theorem to decouple the system.The SIM has exponential convergence so that the error decreases exponentially with the sample density on the surfaces,and requires only about 2–3 points per wavelength(PPW)to reach engineering accuracy defined as higher than 99%accuracy(or with an error smaller than 1%).Numerical results demonstrate that the SIM is much more accurate and efficient than the method of moments(MoM),and thus can be potentially used as the exact radiation boundary condition in the finite element and spectral element methods.
文摘Low-earth orbit(LEO)satellite networks ignite global wireless connectivity.However,signal outages and co-channel interference limit the coverage in traditional LEO satellite networks where a user is served by a single satellite.This paper explores the possibility of satellite cooperation in the downlink transmissions.Using tools from stochastic geometry,we model and analyze the downlink coverage of a typical user with satellite cooperation under Nakagami fading channels.Moreover,we derive the joint distance distribution of cooperative LEO satellites to the typical user.Our model incorporates fading channels,cooperation among several satellites,satellites'density and altitude,and co-channel interference.Extensive Monte Carlo simulations are performed to validate analytical results.Simulation and numerical results suggest that coverage with LEO satellites cooperation considerably exceeds coverage without cooperation.Moreover,there are optimal satellite density and satellite altitude that maximize the coverage probability,which gives valuable network design insights.
基金supported by the National Natural Science Foundation of China(22071004,21933001 and 22150013)
文摘Organic chemistry is undergoing a major paradigm shift,moving from a labor-intensive approach to a new era dominated by automation and artificial intelligence(AI).This transformative shift is being driven by technological advances,the ever-increasing demand for greater research efficiency and accuracy,and the burgeoning growth of interdisciplinary research.AI models,supported by computational power and algorithms,are drastically reshaping synthetic planning and introducing groundbreaking ways to tackle complex molecular synthesis.In addition,autonomous robotic systems are rapidly accelerating the pace of discovery by performing tedious tasks with unprecedented speed and precision.This article examines the multiple opportunities and challenges presented by this paradigm shift and explores its far-reaching implications.It provides valuable insights into the future trajectory of organic chemistry research,which is increasingly defined by the synergistic interaction of automation and AI.