The ubiquitous lipid-derived molecules N-acylethanolamines(NAEs)have multiple immune functions in mammals,but their roles and mechanisms in plant defense response during changing environment remain largely unclear.Her...The ubiquitous lipid-derived molecules N-acylethanolamines(NAEs)have multiple immune functions in mammals,but their roles and mechanisms in plant defense response during changing environment remain largely unclear.Here,we found that exogenous NAE18:0 and NAE18:2 promoted defense against the necrotrophic pathogen Botrytis cinerea but suppressed defense to the hemi-biotrophic pathogen Pseudomonas syringae pv.tomato(Pst)DC3000 in tomato.The knocking-down and overexpression function analysis of the pathogen-responsive NAE synthetic gene PHOSPHOLIPASE Dγ(PLDγ)and hydrolytic gene FATTY ACID AMID HYDROLASE 1(FAAH1)revealed that the NAE pathway is crucial for plant defense response.Using exogenous applications and SA-abolished NahG plants,we unveiled the antagonistic relationship between NAE and SA in plant defense response.Elevated CO_(2) and temperature significantly changed the NAE pathway in response to pathogens,while inhibition of the NAE pathway led to the alternation of environment-mediated defense variations against Pst DC3000 in tomato,indicating that NAE pathway is associated with plant defense variations in response to elevated CO_(2) and temperature.The results herein reveal a new function of NAE in plant defense,and its involvement in environment-mediated defense variation in tomato.These findings shed light on the NAE-based plant defense,which may have relevance to crop disease management in future changing climate.展开更多
To examine the effect of processing parameters on microstructural evolution and to obtain the excellent combination of strength and toughness, simulation of thermo-mechanical processing was conducted using the Gleeble...To examine the effect of processing parameters on microstructural evolution and to obtain the excellent combination of strength and toughness, simulation of thermo-mechanical processing was conducted using the Gleeble machine. Trial production was then conducted under the conditions obtained by Gleeble tests. Based on the results of microstructure analysis and mechanical property evaluation, the relationship between microstructural features and mechanical properties was elucidated. The result shows that the volume fraction of constituted phases can be controlled through adjusting the cooling rate and finish cooling temperature in order to get different strength levels. As cooling rate increases, the volume fraction of upper bainite increases, which leads to the increase of strength. The upper shelf energy （USE） increases with increasing volume fraction of acicular ferrite in bainite base because of the small effective acicular ferrite grain size. Ductile-brittle transition temperature （DBTT） decreases with increasing acicular ferrite volume fraction. High reduction in the rough stage has great influence on grain refinement.展开更多
The immune microenvironment induced by biomaterials played vital roles in bone regeneration.Hydroxyapatite(HA)and its ion-substituted derivates represent a large class of core inorganic materials for bone tissue engin...The immune microenvironment induced by biomaterials played vital roles in bone regeneration.Hydroxyapatite(HA)and its ion-substituted derivates represent a large class of core inorganic materials for bone tissue engineering.Although ion substitution was proved to be a potent way to grant HA more biological functions,few studies focused on the immunomodulatory properties of ion-doped HA.Herein,to explore the potential osteoimmunomodulatory effects of ion-doped HA,zinc and strontium co-assembled into HA through a collagen template biomimetic way(ZnSr-Col-HA)was successfully achieved.It was found that ZnSr-Col-HA could induce a favorable osteo-immune microenvironment by stimulating macrophages.Furthermore,ZnSr-Col-HA demonstrated a procedural promoting effect on osteogenic differentiation of bone marrow mesenchymal stem cells(BMSCs)in vitro.Specifically,the osteo-immune microenvironment acted as a dominant factor in promoting osteogenic gene expressions at the early stage through OSM signal pathway.Whereas the direct stimulating effects on BMSCs by Zn^(2+)/Sr^(2+) were more effectively at the later stage with Nfatc1/Maf and Wnt signals activated.In vivo study confirmed strong promoting effects of ZnSr-Col-HA on critical-sized cranial defect repair.The current study indicated that such a combined biomaterial design philosophy of dual ion-doping and biomimetic molecular co-assembly to endow HA applicable osteoimmunomodulatory characteristics might bring up a new cutting-edge concept for bone regeneration study.展开更多
The occurrence and fate of hydroxylated polybrominated diphenyl ethers（OH-PBDEs） and methoxylated polybrominated diphenyl ethers（Me O-PBDEs） have received significant attention. However, there is limited informati...The occurrence and fate of hydroxylated polybrominated diphenyl ethers（OH-PBDEs） and methoxylated polybrominated diphenyl ethers（Me O-PBDEs） have received significant attention. However, there is limited information on the metabolism relationship between OH-pentaB DEs and MeO-pentaB DEs that were frequently detected with relatively high concentrations in the environment. In this study, the biotransformation between OH-BDE-99 and MeO-BDE-99 was investigated in rice, wheat, and soybean plants. All the three plants can metabolize OH-BDE-99 to corresponding homologous methoxylated metabolites, while the transformation from MeO-BDE-99 to OH-BDE-99 could only be found in soybean. The conversion of parent compounds was the highest in soybean, followed by wheat and rice. Transformation products were found mainly in the roots, with few metabolites being translocated to the shoots and solution after exposure. The results of this study provide valuable information for a better understanding of the accumulation and transformation of OH-PBDEs and MeO-PBDEs in different plants.展开更多
Dynamic reactive power compensation equipment typically requires a fast response to output the necessary reactive power.The term"dynamic response time of reactive power"is often used but has never been clear...Dynamic reactive power compensation equipment typically requires a fast response to output the necessary reactive power.The term"dynamic response time of reactive power"is often used but has never been clearly defined.This paper summarizes the reactive power calculations under different definitions and algorithms and considers these calculations in terms of signal processing to simulate and analyze the step response.This paper subsequently focuses on the widely used instantaneous reactive power algorithm and finally concludes that the dynamic reactive power response time closely depends on the reactive power calculation method itself.The single-phase instantaneous reactive power algorithm has the fastest response time.The reactive power response time of dynamic reactive devices in power systems is a minimum of a quarter of one cycle time for the well-known and widely used single-phase reactive power algorithms.展开更多
Quantitative remote sensing product(QRSP)validation is a complex process to assess the accuracy and uncertainty independently using reference data with multiple land cover types and long-time series.A web-based system...Quantitative remote sensing product(QRSP)validation is a complex process to assess the accuracy and uncertainty independently using reference data with multiple land cover types and long-time series.A web-based system named as LAnd surface remote sensing Product VAlidation system(LAPVAS)is described in this paper,which is used to implement the QRSPs validation process automatically.The LAPAVS has two subsystems,the Validation Databases Subsystem and the Accuracy Evaluation Subsystem.Three functions have been implemented by the two subsystems for a comprehensive QRSP validation:(1)a standardized processing of reference data and storage of these data in validation databases;(2)a consistent and comprehensive validation procedure to assess the QRSPs’accuracy and uncertainty;and(3)a visual process customization tool with which the users can register new validation data,host new reference data,and readjust the validation workflows for the QRSP accuracy assessment.In LAPVAS,more than 100 GB of reference data warehoused in validation databases for 13 types of QRSPs’validation.One of the key QRSPs,land surface albedo,is selected as an example to illustrate the application of LAPVAS.It is demonstrated that the LAPVAS has a good performance in the land surface remote sensing product validation.展开更多
One of the essential steps for satellite albedo validation is upscaling in situ measurements to corresponding pixel scale over relatively heterogeneous land surfaces.Although the multi-scale validation strategy is app...One of the essential steps for satellite albedo validation is upscaling in situ measurements to corresponding pixel scale over relatively heterogeneous land surfaces.Although the multi-scale validation strategy is applicable for heterogeneous surfaces,the calibration of the high-resolution imagery during upscaling process is never perfect,and thus the upscaling results suffer from errors.The regression-kriging(RK)technique can compensate the calibration part by applying kriging to upscale residuals and produce more accurate upscaling results.In this paper,in situ measurements and high spatial resolution albedo imagery combined with RK technique was proposed.This method is illustrated by upscaling surface albedo from in situ measurements scale to the coarse pixel scale in the core experimental area of HiWATER,where 17 WSN nodes were deployed at heterogeneous area.The upscaling results of this method were compared with the upscaling results from multi-scale strategy.The results show that the upscaling method based on in situ measurements and high-resolution imagery combined with RK technique can capture the spatial characteristics of surface albedo better.Further,an attempt was made to expand this method in time series.Finally,a preliminary validation of the Moderate Resolution Imaging Spectroradiometer albedo product was performed as the tentative application.展开更多
Due to the spatial heterogeneity and the spatial scale mismatch between in situ and satellite-based measurements,optimal ground sampling should be made to increase the representativeness of in situ observations. There...Due to the spatial heterogeneity and the spatial scale mismatch between in situ and satellite-based measurements,optimal ground sampling should be made to increase the representativeness of in situ observations. Therefore,many ground sampling strategies have been proposed,but their performance within the coarse pixel has not been evaluated. Hence,this study evaluated four typical methods regarding their ability to obtain pixel scale ground ‘truth’. Random combination (RC) performs best,with the always fewest samples to satisfy representativeness errors (REs) of 3% in the case of a small number of samples. When the goal of sampling is to obtain in situ measurements with REs close to 0 at the expense of increasing the number of samples,cumulative representativeness sampling (CRS) is more effective than RC in less heterogeneous areas. Geo-statistical model-based sampling (GSS) does not work well because the number of samples within the coarse pixel scale cannot support a robust semi-variogram model. Stratified sampling (SS) is highly dependent on spatial heterogeneity and does not work well in the case of small sample sizes. This study gives important guidance for ground sample deployment within the coarse pixel for validation of coarse-resolution satellite albedo products over a heterogeneous surface.展开更多
Upscaling ground albedo is challenged by the serious discrepancy between the heterogeneity of land surfaces and the small number of ground-based measurements.Conventional ground-based measurements cannot provide suffi...Upscaling ground albedo is challenged by the serious discrepancy between the heterogeneity of land surfaces and the small number of ground-based measurements.Conventional ground-based measurements cannot provide sufficient information on the characteristics of surface albedo at the scale of coarse pixels over heterogeneous land surfaces.One method of overcoming this problem is to introduce high-resolution albedo imagery as ancillary information for upscaling.However,due to the low frequency of updating of high-resolution albedo maps,upscaling time series of ground-based albedo measurements is difficult.This paper proposes a method that is based on the idea of conceptual universal scaling methodology for establishing a spatiotemporal trend surface using very few high-resolution images and time series of ground-based measurements for spatial-temporal upscaling of albedo.The construction of the spatiotemporal trend surface incorporates the spatial information provided by auxiliary remote sensing images and the temporal information provided by long time series of ground observations.This approach was illustrated by upscaling ground-based fine-scale albedo measurements to a coarse scale over the core study area in HiWATER.The results indicate that this method can characterize the spatiotemporal variations in surface albedo well,and the overall correlation coefficient was 0.702 during the study period.展开更多
基金This work was supported by the Key Research and Development Program of Zhejiang Province(2021C02040)the National Natural Science Foundation of China(32172650,31902097)+1 种基金the Natural Science Foundation of Zhejiang Province(LR19C150001)the Starry Night Science Fund of Zhejiang University Shanghai Insti-tute for Advanced Study(SN-ZJU-SIAS-0011).
文摘The ubiquitous lipid-derived molecules N-acylethanolamines(NAEs)have multiple immune functions in mammals,but their roles and mechanisms in plant defense response during changing environment remain largely unclear.Here,we found that exogenous NAE18:0 and NAE18:2 promoted defense against the necrotrophic pathogen Botrytis cinerea but suppressed defense to the hemi-biotrophic pathogen Pseudomonas syringae pv.tomato(Pst)DC3000 in tomato.The knocking-down and overexpression function analysis of the pathogen-responsive NAE synthetic gene PHOSPHOLIPASE Dγ(PLDγ)and hydrolytic gene FATTY ACID AMID HYDROLASE 1(FAAH1)revealed that the NAE pathway is crucial for plant defense response.Using exogenous applications and SA-abolished NahG plants,we unveiled the antagonistic relationship between NAE and SA in plant defense response.Elevated CO_(2) and temperature significantly changed the NAE pathway in response to pathogens,while inhibition of the NAE pathway led to the alternation of environment-mediated defense variations against Pst DC3000 in tomato,indicating that NAE pathway is associated with plant defense variations in response to elevated CO_(2) and temperature.The results herein reveal a new function of NAE in plant defense,and its involvement in environment-mediated defense variation in tomato.These findings shed light on the NAE-based plant defense,which may have relevance to crop disease management in future changing climate.
文摘To examine the effect of processing parameters on microstructural evolution and to obtain the excellent combination of strength and toughness, simulation of thermo-mechanical processing was conducted using the Gleeble machine. Trial production was then conducted under the conditions obtained by Gleeble tests. Based on the results of microstructure analysis and mechanical property evaluation, the relationship between microstructural features and mechanical properties was elucidated. The result shows that the volume fraction of constituted phases can be controlled through adjusting the cooling rate and finish cooling temperature in order to get different strength levels. As cooling rate increases, the volume fraction of upper bainite increases, which leads to the increase of strength. The upper shelf energy （USE） increases with increasing volume fraction of acicular ferrite in bainite base because of the small effective acicular ferrite grain size. Ductile-brittle transition temperature （DBTT） decreases with increasing acicular ferrite volume fraction. High reduction in the rough stage has great influence on grain refinement.
基金supported by National Key R&D Project(2018YFC1105701)of ChinaNational Natural Science Foundation of China(31870960,81801850)the Fundamental Research Funds for the Central Universities,HUST(2019kfyXMBZ021,2020kfyXJJS115).
文摘The immune microenvironment induced by biomaterials played vital roles in bone regeneration.Hydroxyapatite(HA)and its ion-substituted derivates represent a large class of core inorganic materials for bone tissue engineering.Although ion substitution was proved to be a potent way to grant HA more biological functions,few studies focused on the immunomodulatory properties of ion-doped HA.Herein,to explore the potential osteoimmunomodulatory effects of ion-doped HA,zinc and strontium co-assembled into HA through a collagen template biomimetic way(ZnSr-Col-HA)was successfully achieved.It was found that ZnSr-Col-HA could induce a favorable osteo-immune microenvironment by stimulating macrophages.Furthermore,ZnSr-Col-HA demonstrated a procedural promoting effect on osteogenic differentiation of bone marrow mesenchymal stem cells(BMSCs)in vitro.Specifically,the osteo-immune microenvironment acted as a dominant factor in promoting osteogenic gene expressions at the early stage through OSM signal pathway.Whereas the direct stimulating effects on BMSCs by Zn^(2+)/Sr^(2+) were more effectively at the later stage with Nfatc1/Maf and Wnt signals activated.In vivo study confirmed strong promoting effects of ZnSr-Col-HA on critical-sized cranial defect repair.The current study indicated that such a combined biomaterial design philosophy of dual ion-doping and biomimetic molecular co-assembly to endow HA applicable osteoimmunomodulatory characteristics might bring up a new cutting-edge concept for bone regeneration study.
基金supported by the National Basic Research Program (973) of China (No. 2014CB441104)National Natural Science Foundation of China (Nos. 21520102009 and 21137003)the Zhejiang Provincial Natural Science Foundation of China (LY14B070009)
文摘The occurrence and fate of hydroxylated polybrominated diphenyl ethers（OH-PBDEs） and methoxylated polybrominated diphenyl ethers（Me O-PBDEs） have received significant attention. However, there is limited information on the metabolism relationship between OH-pentaB DEs and MeO-pentaB DEs that were frequently detected with relatively high concentrations in the environment. In this study, the biotransformation between OH-BDE-99 and MeO-BDE-99 was investigated in rice, wheat, and soybean plants. All the three plants can metabolize OH-BDE-99 to corresponding homologous methoxylated metabolites, while the transformation from MeO-BDE-99 to OH-BDE-99 could only be found in soybean. The conversion of parent compounds was the highest in soybean, followed by wheat and rice. Transformation products were found mainly in the roots, with few metabolites being translocated to the shoots and solution after exposure. The results of this study provide valuable information for a better understanding of the accumulation and transformation of OH-PBDEs and MeO-PBDEs in different plants.
文摘Dynamic reactive power compensation equipment typically requires a fast response to output the necessary reactive power.The term"dynamic response time of reactive power"is often used but has never been clearly defined.This paper summarizes the reactive power calculations under different definitions and algorithms and considers these calculations in terms of signal processing to simulate and analyze the step response.This paper subsequently focuses on the widely used instantaneous reactive power algorithm and finally concludes that the dynamic reactive power response time closely depends on the reactive power calculation method itself.The single-phase instantaneous reactive power algorithm has the fastest response time.The reactive power response time of dynamic reactive devices in power systems is a minimum of a quarter of one cycle time for the well-known and widely used single-phase reactive power algorithms.
基金This work was jointly supported by National Natural Science Foundation of China[41671363]National Basic Research Program of China[2013CB733401]National High Technology Research and Development Program of China:[2013AA12A301].
文摘Quantitative remote sensing product(QRSP)validation is a complex process to assess the accuracy and uncertainty independently using reference data with multiple land cover types and long-time series.A web-based system named as LAnd surface remote sensing Product VAlidation system(LAPVAS)is described in this paper,which is used to implement the QRSPs validation process automatically.The LAPAVS has two subsystems,the Validation Databases Subsystem and the Accuracy Evaluation Subsystem.Three functions have been implemented by the two subsystems for a comprehensive QRSP validation:(1)a standardized processing of reference data and storage of these data in validation databases;(2)a consistent and comprehensive validation procedure to assess the QRSPs’accuracy and uncertainty;and(3)a visual process customization tool with which the users can register new validation data,host new reference data,and readjust the validation workflows for the QRSP accuracy assessment.In LAPVAS,more than 100 GB of reference data warehoused in validation databases for 13 types of QRSPs’validation.One of the key QRSPs,land surface albedo,is selected as an example to illustrate the application of LAPVAS.It is demonstrated that the LAPVAS has a good performance in the land surface remote sensing product validation.
基金This research is jointly supported by the National Basic Research Program of China under Grant 2013CB733401the Natural Science Foundation of China under Grant nos.41671363 and 91125003.
文摘One of the essential steps for satellite albedo validation is upscaling in situ measurements to corresponding pixel scale over relatively heterogeneous land surfaces.Although the multi-scale validation strategy is applicable for heterogeneous surfaces,the calibration of the high-resolution imagery during upscaling process is never perfect,and thus the upscaling results suffer from errors.The regression-kriging(RK)technique can compensate the calibration part by applying kriging to upscale residuals and produce more accurate upscaling results.In this paper,in situ measurements and high spatial resolution albedo imagery combined with RK technique was proposed.This method is illustrated by upscaling surface albedo from in situ measurements scale to the coarse pixel scale in the core experimental area of HiWATER,where 17 WSN nodes were deployed at heterogeneous area.The upscaling results of this method were compared with the upscaling results from multi-scale strategy.The results show that the upscaling method based on in situ measurements and high-resolution imagery combined with RK technique can capture the spatial characteristics of surface albedo better.Further,an attempt was made to expand this method in time series.Finally,a preliminary validation of the Moderate Resolution Imaging Spectroradiometer albedo product was performed as the tentative application.
基金supported by the National Natural Science Foundation of China [grant number 42071296]the China High-Resolution Earth Observation System [grant number 21-Y20B01-9001-19/22]the Fundamental Research Funds for the Central Universities [grant number lzujbky-2022-09].
文摘Due to the spatial heterogeneity and the spatial scale mismatch between in situ and satellite-based measurements,optimal ground sampling should be made to increase the representativeness of in situ observations. Therefore,many ground sampling strategies have been proposed,but their performance within the coarse pixel has not been evaluated. Hence,this study evaluated four typical methods regarding their ability to obtain pixel scale ground ‘truth’. Random combination (RC) performs best,with the always fewest samples to satisfy representativeness errors (REs) of 3% in the case of a small number of samples. When the goal of sampling is to obtain in situ measurements with REs close to 0 at the expense of increasing the number of samples,cumulative representativeness sampling (CRS) is more effective than RC in less heterogeneous areas. Geo-statistical model-based sampling (GSS) does not work well because the number of samples within the coarse pixel scale cannot support a robust semi-variogram model. Stratified sampling (SS) is highly dependent on spatial heterogeneity and does not work well in the case of small sample sizes. This study gives important guidance for ground sample deployment within the coarse pixel for validation of coarse-resolution satellite albedo products over a heterogeneous surface.
基金This research is jointly supported by the National Basic Research Program of China[grant number 2013CB733401]the National Natural Science Foundation of China[grant numbers 41671363 and 91125003].
文摘Upscaling ground albedo is challenged by the serious discrepancy between the heterogeneity of land surfaces and the small number of ground-based measurements.Conventional ground-based measurements cannot provide sufficient information on the characteristics of surface albedo at the scale of coarse pixels over heterogeneous land surfaces.One method of overcoming this problem is to introduce high-resolution albedo imagery as ancillary information for upscaling.However,due to the low frequency of updating of high-resolution albedo maps,upscaling time series of ground-based albedo measurements is difficult.This paper proposes a method that is based on the idea of conceptual universal scaling methodology for establishing a spatiotemporal trend surface using very few high-resolution images and time series of ground-based measurements for spatial-temporal upscaling of albedo.The construction of the spatiotemporal trend surface incorporates the spatial information provided by auxiliary remote sensing images and the temporal information provided by long time series of ground observations.This approach was illustrated by upscaling ground-based fine-scale albedo measurements to a coarse scale over the core study area in HiWATER.The results indicate that this method can characterize the spatiotemporal variations in surface albedo well,and the overall correlation coefficient was 0.702 during the study period.
