The C-band wind speed retrieval models, CMOD4, CMOD - IFR2, and CMOD5 were applied to retrieval of sea surface wind speeds from ENVISAT （European environmental satellite） ASAR （advanced synthetic aperture radar） d...The C-band wind speed retrieval models, CMOD4, CMOD - IFR2, and CMOD5 were applied to retrieval of sea surface wind speeds from ENVISAT （European environmental satellite） ASAR （advanced synthetic aperture radar） data in the coastal waters near Hong Kong during a period from October 2005 to July 2007. The retrieved wind speeds are evaluated by comparing with buoy measurements and the QuikSCAT （quick scatterometer） wind products. The results show that the CMOD4 model gives the best performance at wind speeds lower than 15 m/s. The correlation coefficients with buoy and QuikSCAT winds are 0.781 and 0.896, respectively. The root mean square errors are the same 1.74 m/s. Namely, the CMOD4 model is the best one for sea surface wind speed retrieval from ASAR data in the coastal waters near Hong Kong.展开更多
The third Chinese National Arctic Research Expedition （CHINARE） was conducted in the summer of 2008. During the survey, the surface seawater partial pressure of CO2 （pCO2） was measured, and sea water samples were ...The third Chinese National Arctic Research Expedition （CHINARE） was conducted in the summer of 2008. During the survey, the surface seawater partial pressure of CO2 （pCO2） was measured, and sea water samples were collected for CO2 measurement in the Canada Basin. The distribution of pCO2 in the Canada Basin was determined, the influencing factors were addressed, and the air-sea CO2 flux in the Canada Basin was evaluated. The Canada Basin was divided into three regions： the ice-free zone （south of 77°N）, the partially ice-covered zone （77°-80°N）, and the heavily ice-covered zone （north of 80°N）. In the ice-free zone, pCO2 was high （320 to 368 patm, 1 patm=0.101 325 Pa）, primarily due to rapid equilibration with atmospheric CO2 over a short time. In the partially ice-covered zone, the surface pCOs was relatively low （250 to 270 patm） due to ice-edge blooms and icemelt water dilution. In the heavily ice-covered zone, the seawater pCO2 varied between 270 and 300 laatm due to biological COs removal, the transportation of low pCOs water northward, and heavy ice cover. The surface seawater pCO2 during the survey was undersaturated with respect to the atmosphere in the Canada Basin, and it was a net sink for atmospheric CO2. The summertime net CO2 uptake of the ice-free zone, the partially ice-covered zone and the heavily ice-covered zone was （4.14±1.08）, （1.79±0.19）, and （0.57±0.03） Tg/a （calculated by carbon, 1 Tg=10^12 g）, respectively. Overall, the net COs sink of the Canada Basin in the summer of 2008 was （6.5＋1.3） Tg/a, which accounted for 4%-10% of the Arctic Ocean COs sink.展开更多
Time series of sea surface temperature (SST),wind speed and significant wave height (SWH) from meteorological buoys of the National Data Buoy Center (NDBC) are useful for studying the interannual variability and trend...Time series of sea surface temperature (SST),wind speed and significant wave height (SWH) from meteorological buoys of the National Data Buoy Center (NDBC) are useful for studying the interannual variability and trend of these quantities at the buoy areas. The measurements from 4 buoys (B51001,B51002,B51003 and B51004) in the Hawaii area are used to study the responses of the quantities to EI Ni?o and Southern Oscillation (ENSO). Long-term averages of these data reflect precise seasonal and climatological characteristics of SST,wind speed and SWH around the Hawaii area. Buoy observations from B51001 suggest a significant warming trend which is,however,not very clear from the other three buoys. Compared with the variability of SST and SWH,the wind speeds from the buoy observations show an increasing trend. The impacts of EI Nio on SST and wind waves are also shown. Sea level data observed by altimeter during October 1992 to September 2006 are analyzed to investigate the variability of sea level in the Hawaii area. The results also show an increasing trend in sea level anomaly (SLA). The low-passed SLA in the Hawaii area is consistent with the inverse phase of the low-passed SOI (Southern Oscillation Index). Compared with the low-passed SOI and PDO (Pacific Decadal Oscillation),the low-passed PNA (Pacific-North America Index) has a better correlation with the low-passed SLA in the Hawaii area.展开更多
The northern South China Sea(NSCS) is a dynamically complex region whose shelf and slope currents are driven by different mechanisms. In this study, we used field measurements to identify clear interannual variations ...The northern South China Sea(NSCS) is a dynamically complex region whose shelf and slope currents are driven by different mechanisms. In this study, we used field measurements to identify clear interannual variations in the circulation related to the El Ni?o-Southern Oscillation cycle. To investigate the modulation mechanisms, we used a high-resolution numerical model that covers the shelf and slope regions of the NSCS. The results indicate that the stronger southwestward slope current during La Ni?a and stronger northeastward shelf current during El Ni?o in summer and winter are largely related to changes in wind forcing. The Kuroshio intrusion into the NSCS does not appear to significantly affect the circulation in the southwestern shelf region.展开更多
Peptide frictions in water nanofilms of various thicknesses on a mica surface are studied via molecular dynamics simulations. We find that the forced lateral motion of the peptide exhibits stick-slip behaviour at low ...Peptide frictions in water nanofilms of various thicknesses on a mica surface are studied via molecular dynamics simulations. We find that the forced lateral motion of the peptide exhibits stick-slip behaviour at low water coverage; in contrast, the smooth gliding motion is observed at higher water coverage. The adsorbed peptide can form direct peptide-surface hydrogen bonds as well as indirect peptide-water-surface hydrogen bonds with the substrate. We propose that the stick-slip phenomenon is attributed to the overall effects of direct and indirect hydrogen bonds formed between the surface and the peptide.展开更多
Dental caries is one of the most common oral diseases in the world.This study was tantamount to investigate the combinatory effects of an amelogenin-derived peptide(called QP5)and fluoride on the remineralization of a...Dental caries is one of the most common oral diseases in the world.This study was tantamount to investigate the combinatory effects of an amelogenin-derived peptide(called QP5)and fluoride on the remineralization of artificial enamel caries.The peptide QP5 was synthesized and characterized,and the binding capability of the peptide on hydroxyapatite(HA)and demineralized tooth enamel surface was analysed.Then,the mineralization function of the peptide and fluoride was studied through the spontaneous mineralization testing and remineralization on enamel caries in vitro.First,the novel peptide QP5 could bind on the hydroxyapatite and demineralized tooth enamel surfaces.Second,QP5 can transitorily stabilize the formation of amorphous calcium phosphate and direct the transformation into hydroxyapatite crystals alone and in combination with fluoride.In addition,compared to blocks treated by peptide QP5 alone or fluoride,the sample blocks showed significantly higher surface microhardness,lower mineral loss and shallower lesion depth after treatment with a combination of QP5 and fluoride at high or low concentrations.The peptide QP5 could control the crystallization of hydroxyapatite,and combinatory application of peptide QP5 and fluoride had a potential synergistic effect on the remineralization of enamel caries.展开更多
Several novel biomaterials have been developed for dental pulp capping by inducing tertiary dentin formation.The aim of this study was to evaluate the effect of QP5,an amelogenin-based peptide,on the mineralization of...Several novel biomaterials have been developed for dental pulp capping by inducing tertiary dentin formation.The aim of this study was to evaluate the effect of QP5,an amelogenin-based peptide,on the mineralization of dental pulp cells(DPCs)in vitro and in vivo.The cell viability of human DPCs(hDPCs)after treatment with QP5 was determined using the Cell Counting Kit-8(CCK-8).Migration of hDPCs was assessed using scratch assays,and the pro-mineralization effect was determined using alkaline phosphatase(ALP)staining,alizarin red staining and the expression of mineralization-related genes and proteins.The results showed that QP5 had little effect on the cell viability,and significantly enhanced the migration capability of hDPCs.QP5 promoted the formation of mineralized nodules,and upregulated the activity of ALP,the expression of mRNA and proteins of mineralization-related genes.A pulp capping model in rats was generated to investigate the biological effect of QP5.The results of micro-computed tomography and haematoxylin and eosin staining indicated that the formation of tertiary dentin in QP5-capping groups was more prominent than that in the negative control group.These results indicated the potential of QP5 as a pulp therapy agent.展开更多
基金Research Grant Council under contract No.461907Innovation and Technology Commission under contract No.GHP/026/06+1 种基金partly by China Postdoctoral Science Foundation under contract No.2008041345 for ChengONR under contract NosN00014-05-1-0328 and N00014-05-1-0606 for Zheng
文摘The C-band wind speed retrieval models, CMOD4, CMOD - IFR2, and CMOD5 were applied to retrieval of sea surface wind speeds from ENVISAT （European environmental satellite） ASAR （advanced synthetic aperture radar） data in the coastal waters near Hong Kong during a period from October 2005 to July 2007. The retrieved wind speeds are evaluated by comparing with buoy measurements and the QuikSCAT （quick scatterometer） wind products. The results show that the CMOD4 model gives the best performance at wind speeds lower than 15 m/s. The correlation coefficients with buoy and QuikSCAT winds are 0.781 and 0.896, respectively. The root mean square errors are the same 1.74 m/s. Namely, the CMOD4 model is the best one for sea surface wind speed retrieval from ASAR data in the coastal waters near Hong Kong.
基金The National Natural Science Foundation of China(NSFC) under contract Nos 41476173 and 41406221the Chinese Projects for Investigations and Assessments of the Arctic and Ant Arctic under contract Nos CHINARE2012-04-04 and 2012-04-03+1 种基金the Fujian Science and Technology Innovation Leader Project 2016the Scientific Research Foundation of Third Institute of Oceanography,SOA under contract No.2014006
文摘The third Chinese National Arctic Research Expedition （CHINARE） was conducted in the summer of 2008. During the survey, the surface seawater partial pressure of CO2 （pCO2） was measured, and sea water samples were collected for CO2 measurement in the Canada Basin. The distribution of pCO2 in the Canada Basin was determined, the influencing factors were addressed, and the air-sea CO2 flux in the Canada Basin was evaluated. The Canada Basin was divided into three regions： the ice-free zone （south of 77°N）, the partially ice-covered zone （77°-80°N）, and the heavily ice-covered zone （north of 80°N）. In the ice-free zone, pCO2 was high （320 to 368 patm, 1 patm=0.101 325 Pa）, primarily due to rapid equilibration with atmospheric CO2 over a short time. In the partially ice-covered zone, the surface pCOs was relatively low （250 to 270 patm） due to ice-edge blooms and icemelt water dilution. In the heavily ice-covered zone, the seawater pCO2 varied between 270 and 300 laatm due to biological COs removal, the transportation of low pCOs water northward, and heavy ice cover. The surface seawater pCO2 during the survey was undersaturated with respect to the atmosphere in the Canada Basin, and it was a net sink for atmospheric CO2. The summertime net CO2 uptake of the ice-free zone, the partially ice-covered zone and the heavily ice-covered zone was （4.14±1.08）, （1.79±0.19）, and （0.57±0.03） Tg/a （calculated by carbon, 1 Tg=10^12 g）, respectively. Overall, the net COs sink of the Canada Basin in the summer of 2008 was （6.5＋1.3） Tg/a, which accounted for 4%-10% of the Arctic Ocean COs sink.
基金the National Basic Research Program of China under Grant No 973-2007CB411807National High Technology Development Project under Grant No 863-2006AA09Z140+1 种基金China Postdoctoral Science Foundation funded project under Grant No 2008041345the Scientific Research Starting Foundation for Doctoral of Institute of Meteorology,PLA University of Science and Technology
文摘Time series of sea surface temperature (SST),wind speed and significant wave height (SWH) from meteorological buoys of the National Data Buoy Center (NDBC) are useful for studying the interannual variability and trend of these quantities at the buoy areas. The measurements from 4 buoys (B51001,B51002,B51003 and B51004) in the Hawaii area are used to study the responses of the quantities to EI Ni?o and Southern Oscillation (ENSO). Long-term averages of these data reflect precise seasonal and climatological characteristics of SST,wind speed and SWH around the Hawaii area. Buoy observations from B51001 suggest a significant warming trend which is,however,not very clear from the other three buoys. Compared with the variability of SST and SWH,the wind speeds from the buoy observations show an increasing trend. The impacts of EI Nio on SST and wind waves are also shown. Sea level data observed by altimeter during October 1992 to September 2006 are analyzed to investigate the variability of sea level in the Hawaii area. The results also show an increasing trend in sea level anomaly (SLA). The low-passed SLA in the Hawaii area is consistent with the inverse phase of the low-passed SOI (Southern Oscillation Index). Compared with the low-passed SOI and PDO (Pacific Decadal Oscillation),the low-passed PNA (Pacific-North America Index) has a better correlation with the low-passed SLA in the Hawaii area.
基金supported by the National Key Research and Development Program of China (No. 2016YFC1401604)the National Natural Science Foundation of China (No. 41806035)+5 种基金the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou)(No. GML2019ZD0305)the National Natural Science Foundation of China (Nos. 4173053641890805)the Innovation Academy of South China Sea Ecology and Environmental Engineering,Chinese Academy of Sciences (No. ISEE2019ZR02)the Guangdong Basic and Applied Basic Research Foundation (No. 2019A1515012108)the Research Funds from the State Key Laboratory of Tropical Oceanography (No. LTOZZ1803)。
文摘The northern South China Sea(NSCS) is a dynamically complex region whose shelf and slope currents are driven by different mechanisms. In this study, we used field measurements to identify clear interannual variations in the circulation related to the El Ni?o-Southern Oscillation cycle. To investigate the modulation mechanisms, we used a high-resolution numerical model that covers the shelf and slope regions of the NSCS. The results indicate that the stronger southwestward slope current during La Ni?a and stronger northeastward shelf current during El Ni?o in summer and winter are largely related to changes in wind forcing. The Kuroshio intrusion into the NSCS does not appear to significantly affect the circulation in the southwestern shelf region.
基金supported by the National Natural Science Foundation of China (Grant No.10825520)the National Basic Research Program of China (Grant No.2007CB936000)the National Science Foundation for Post-Doctoral Scientists of China (Grant No.20100480645)
文摘Peptide frictions in water nanofilms of various thicknesses on a mica surface are studied via molecular dynamics simulations. We find that the forced lateral motion of the peptide exhibits stick-slip behaviour at low water coverage; in contrast, the smooth gliding motion is observed at higher water coverage. The adsorbed peptide can form direct peptide-surface hydrogen bonds as well as indirect peptide-water-surface hydrogen bonds with the substrate. We propose that the stick-slip phenomenon is attributed to the overall effects of direct and indirect hydrogen bonds formed between the surface and the peptide.
基金supported by the National Natural Science Foundation of China(81470734 and 81771062).
文摘Dental caries is one of the most common oral diseases in the world.This study was tantamount to investigate the combinatory effects of an amelogenin-derived peptide(called QP5)and fluoride on the remineralization of artificial enamel caries.The peptide QP5 was synthesized and characterized,and the binding capability of the peptide on hydroxyapatite(HA)and demineralized tooth enamel surface was analysed.Then,the mineralization function of the peptide and fluoride was studied through the spontaneous mineralization testing and remineralization on enamel caries in vitro.First,the novel peptide QP5 could bind on the hydroxyapatite and demineralized tooth enamel surfaces.Second,QP5 can transitorily stabilize the formation of amorphous calcium phosphate and direct the transformation into hydroxyapatite crystals alone and in combination with fluoride.In addition,compared to blocks treated by peptide QP5 alone or fluoride,the sample blocks showed significantly higher surface microhardness,lower mineral loss and shallower lesion depth after treatment with a combination of QP5 and fluoride at high or low concentrations.The peptide QP5 could control the crystallization of hydroxyapatite,and combinatory application of peptide QP5 and fluoride had a potential synergistic effect on the remineralization of enamel caries.
基金This work was supported by the National Natural Science Foundation of China(grants number 81771062 and 81970931).
文摘Several novel biomaterials have been developed for dental pulp capping by inducing tertiary dentin formation.The aim of this study was to evaluate the effect of QP5,an amelogenin-based peptide,on the mineralization of dental pulp cells(DPCs)in vitro and in vivo.The cell viability of human DPCs(hDPCs)after treatment with QP5 was determined using the Cell Counting Kit-8(CCK-8).Migration of hDPCs was assessed using scratch assays,and the pro-mineralization effect was determined using alkaline phosphatase(ALP)staining,alizarin red staining and the expression of mineralization-related genes and proteins.The results showed that QP5 had little effect on the cell viability,and significantly enhanced the migration capability of hDPCs.QP5 promoted the formation of mineralized nodules,and upregulated the activity of ALP,the expression of mRNA and proteins of mineralization-related genes.A pulp capping model in rats was generated to investigate the biological effect of QP5.The results of micro-computed tomography and haematoxylin and eosin staining indicated that the formation of tertiary dentin in QP5-capping groups was more prominent than that in the negative control group.These results indicated the potential of QP5 as a pulp therapy agent.
