A 3 kW radio frequency (RF) magnetron-sputtering unit was used to producezirconia ceramic coatings on hollow turbine blades and vanes, which had been deposited a NiCrAlYbond coat layer by cathodic arc deposition. The ...A 3 kW radio frequency (RF) magnetron-sputtering unit was used to producezirconia ceramic coatings on hollow turbine blades and vanes, which had been deposited a NiCrAlYbond coat layer by cathodic arc deposition. The NiCrAlY coating surface was shot-peened, and theresidual stress in the bond coat layer and the effects of heat treatment on the residual stress arepresented. After shot peening porosities and microgaps disappear in the NiCrAlY bond coat, the wholedepth profile is residual compressive stress. Coarseness tests show that the roughness value (Rz)decreases from 16.4 to 3.3 mu m. The microstructure and phase composition of the coatings wereinvestigated using electron probe microanalysis (EPMA) and X-ray diffraction (XRD). The results showthat the/ NiCrAlY bond coat is composed of gamma and Cr phases, and the A1_2O_3 scales are formednear the interface between the ZrO_2 ceramic layer and the NiCrAlY bond coat. No degradationoccurred to RF sputtered ceramic coatings after oxidating at 1150 deg C for 100 h, heating at 1150deg C for 5 min and then air-cooling for 500 thermal cycles.展开更多
In this study,sea ice thickness(SIT)and sea ice extent(SIE)in the Bohai Sea from 2000 to 2016 were investigated.A surface heat balance equation was applied to calculate SIT using ice surface temperatures estimated fro...In this study,sea ice thickness(SIT)and sea ice extent(SIE)in the Bohai Sea from 2000 to 2016 were investigated.A surface heat balance equation was applied to calculate SIT using ice surface temperatures estimated from the Moderate Resolution Imaging Spectroradiometer(MODIS)data with input from air temperature and wind speed from reanalyzing weather data.No trend was found in SIT during 2000–2016.The mean SIT and SIE during this period were 5.58±0.86 cm and 23×10^(3)±8×10^(3)km^(2),respectively.The largest SIT and SIE periods were observed during the second half of January and the first half of February,respectively.The Spearman correlation coefficient between mean ice thickness and average air temperature from 21 automatic weather stations around the Bohai Sea was–0.94(P<.005),and the coefficient between median ice extent and negative accumulated temperature was–0.503(P<.001).The rate of increase in air temperature around the Bohai Sea is 0.271℃per decade in winter for 1979–2016(P<.05),which is much lower than that in northern polar area(0.648℃per decade).This rate has not resulted in a decreasing trend in SIT and SIE for the past 16 years in the Bohai Sea.展开更多
Gastric acidity-associated disorders such as peptic ulcer and reflux diseases are widespread,and the reported resistance and side effects of currently used medicines suggest an urgent requirement for alternative thera...Gastric acidity-associated disorders such as peptic ulcer and reflux diseases are widespread,and the reported resistance and side effects of currently used medicines suggest an urgent requirement for alternative therapeutic approaches.Here we demonstrate a critical role of ASAP3 in regulating the microvilli structure of parietal cells in vivo,and reveal the feasibility of controlling gastric acidity by targeting ASAP3.Conditional knockout of ASAP3 in mice caused elongation and stacking of microvilli in parietal cells,and substantially decreased gastric acid secretion.These were associated with active assembly of F-actin caused by a higher level of GTP-bound Arf6 GTPase.Consistently,a small molecular compound QS11 inhibited ASAP3 function and significantly reduced gastric acidity in vivo.Of note,the expression of ASAP3 was positively correlated with gastric acid secretion in 90 human cases,and high expression of ASAP3 was associated with reflux disease and peptic ulcer.These results reveal for the first time that ASAP3 regulates the microvilli structures in parietal cells.Our data also suggest ASAP3 as a feasible and drugable therapeutic target for gastric acidity-associated diseases.展开更多
Antarctic tabular icebergs are important active components in the ice sheet-ice shelf-ocean system.Seafloor topography is the key factor that affects the drifting and grounding of icebergs,but it has not been fully in...Antarctic tabular icebergs are important active components in the ice sheet-ice shelf-ocean system.Seafloor topography is the key factor that affects the drifting and grounding of icebergs,but it has not been fully investigated.This study analyzes the impact of seafloor topography on the drifting and grounding of Antarctic tabular icebergs using Bedmap-2 datasets and iceberg route tracking data from Brigham Young University.The results highlight the following points.(1) The quantitative distributions of iceberg grounding events and the tracking points of grounded icebergs are mainly affected by iceberg draft and reach their peak values in sea water with depths between 200 m and 300 m.The peak tracking point number and linear velocity of free-drifting icebergs are found in the Antarctic Slope Front(water depth of approximately 500 m).(2) The area of possible grounding regions of small-scale icebergs calved from ice shelf fronts accounts for 28%of the sea area at water depths less than 2000 m outside the Antarctic coastline periphery(3.62 million km2).Their spatial distribution is mainly around East Antarctica and the Antarctic Peninsula.The area of possible grounding regions of large tabular icebergs with long axes larger than 18.5 km(in water depths of less than 800 m) accounts for 74%of the sea area.(3) The iceberg drifting velocity is positively correlated with ocean depth in areas where the depth is less than 2000 m(R=0.85,P<0.01).This result confirms the effect of water depth variations induced by seafloor topography fluctuations on iceberg drifting velocity.展开更多
文摘A 3 kW radio frequency (RF) magnetron-sputtering unit was used to producezirconia ceramic coatings on hollow turbine blades and vanes, which had been deposited a NiCrAlYbond coat layer by cathodic arc deposition. The NiCrAlY coating surface was shot-peened, and theresidual stress in the bond coat layer and the effects of heat treatment on the residual stress arepresented. After shot peening porosities and microgaps disappear in the NiCrAlY bond coat, the wholedepth profile is residual compressive stress. Coarseness tests show that the roughness value (Rz)decreases from 16.4 to 3.3 mu m. The microstructure and phase composition of the coatings wereinvestigated using electron probe microanalysis (EPMA) and X-ray diffraction (XRD). The results showthat the/ NiCrAlY bond coat is composed of gamma and Cr phases, and the A1_2O_3 scales are formednear the interface between the ZrO_2 ceramic layer and the NiCrAlY bond coat. No degradationoccurred to RF sputtered ceramic coatings after oxidating at 1150 deg C for 100 h, heating at 1150deg C for 5 min and then air-cooling for 500 thermal cycles.
基金the Chinese Arctic and Antarctic Administration,National Natural Science Foundation of China(Grant Nos.41676176,41676182 and 41428603)Chinese Polar Environment Comprehensive Investigation and Assessment Program.
文摘In this study,sea ice thickness(SIT)and sea ice extent(SIE)in the Bohai Sea from 2000 to 2016 were investigated.A surface heat balance equation was applied to calculate SIT using ice surface temperatures estimated from the Moderate Resolution Imaging Spectroradiometer(MODIS)data with input from air temperature and wind speed from reanalyzing weather data.No trend was found in SIT during 2000–2016.The mean SIT and SIE during this period were 5.58±0.86 cm and 23×10^(3)±8×10^(3)km^(2),respectively.The largest SIT and SIE periods were observed during the second half of January and the first half of February,respectively.The Spearman correlation coefficient between mean ice thickness and average air temperature from 21 automatic weather stations around the Bohai Sea was–0.94(P<.005),and the coefficient between median ice extent and negative accumulated temperature was–0.503(P<.001).The rate of increase in air temperature around the Bohai Sea is 0.271℃per decade in winter for 1979–2016(P<.05),which is much lower than that in northern polar area(0.648℃per decade).This rate has not resulted in a decreasing trend in SIT and SIE for the past 16 years in the Bohai Sea.
基金This project was supported by grants from the Major Program of National Natural Science Foundation of China(81530072),the Projects of International Cooperation and Exchanges NSFC(81320108024),and the Innovative group projects(81421001)to Jing-Yuan FangNational Natural Science Foundation of China(81572326,81322036,81272383,81602518,81502015 and 81572303)+4 种基金Top-Notch Young Talents Program of China(ZTZ2015-48)Shanghai Municipal Education Commission-Gaofeng Clinical Medicine Grant Support(20152514)National Key Research and Development(R&D)Plan(2016YFC0906000 and 2016YFC0906002)National Key Technology Support Program(2015BAI13B07)the Doctoral Innovation Fund Projects from Shanghai Jiao Tong University School of Medicine to JQ(BXJ201419).
文摘Gastric acidity-associated disorders such as peptic ulcer and reflux diseases are widespread,and the reported resistance and side effects of currently used medicines suggest an urgent requirement for alternative therapeutic approaches.Here we demonstrate a critical role of ASAP3 in regulating the microvilli structure of parietal cells in vivo,and reveal the feasibility of controlling gastric acidity by targeting ASAP3.Conditional knockout of ASAP3 in mice caused elongation and stacking of microvilli in parietal cells,and substantially decreased gastric acid secretion.These were associated with active assembly of F-actin caused by a higher level of GTP-bound Arf6 GTPase.Consistently,a small molecular compound QS11 inhibited ASAP3 function and significantly reduced gastric acidity in vivo.Of note,the expression of ASAP3 was positively correlated with gastric acid secretion in 90 human cases,and high expression of ASAP3 was associated with reflux disease and peptic ulcer.These results reveal for the first time that ASAP3 regulates the microvilli structures in parietal cells.Our data also suggest ASAP3 as a feasible and drugable therapeutic target for gastric acidity-associated diseases.
基金supported by the National Key Research and Development Program of China(Grant No. 2016YFA0600103)the National Natural Science Foundation of China (Grant Nos.41406211,41476161,41676182 & 41676176)+3 种基金the National Basic Research Program of China(Grant No.2012CB957704)the KeyLaboratory Research Fund of the National Administration of Surveying, Mapping and Geoinformation of China(Grant No.201416)the Specialized Research Fund for the Doctoral Program of Higher Education(Grant No.20120003110030)the Project of International Cooperation and Exchanges CHINARE(Grant No.201611)
文摘Antarctic tabular icebergs are important active components in the ice sheet-ice shelf-ocean system.Seafloor topography is the key factor that affects the drifting and grounding of icebergs,but it has not been fully investigated.This study analyzes the impact of seafloor topography on the drifting and grounding of Antarctic tabular icebergs using Bedmap-2 datasets and iceberg route tracking data from Brigham Young University.The results highlight the following points.(1) The quantitative distributions of iceberg grounding events and the tracking points of grounded icebergs are mainly affected by iceberg draft and reach their peak values in sea water with depths between 200 m and 300 m.The peak tracking point number and linear velocity of free-drifting icebergs are found in the Antarctic Slope Front(water depth of approximately 500 m).(2) The area of possible grounding regions of small-scale icebergs calved from ice shelf fronts accounts for 28%of the sea area at water depths less than 2000 m outside the Antarctic coastline periphery(3.62 million km2).Their spatial distribution is mainly around East Antarctica and the Antarctic Peninsula.The area of possible grounding regions of large tabular icebergs with long axes larger than 18.5 km(in water depths of less than 800 m) accounts for 74%of the sea area.(3) The iceberg drifting velocity is positively correlated with ocean depth in areas where the depth is less than 2000 m(R=0.85,P<0.01).This result confirms the effect of water depth variations induced by seafloor topography fluctuations on iceberg drifting velocity.
