The regulating ways of different water masses affecting the locations and intensities of hypoxia zones were studied based on the time-space continuum data from August 2011 to 2013–2017.The 6-year distribution of the ...The regulating ways of different water masses affecting the locations and intensities of hypoxia zones were studied based on the time-space continuum data from August 2011 to 2013–2017.The 6-year distribution of the hypoxic area in the Changjiang Estuary(CE)and its adjacent waters show that the hypoxic area can be divided into two segments.The southern segment is out of the south branch of the CE,whereas the northern segment is in the junction zone between the South Yellow Sea and the CE.The two segments were divided along the 31.5°–32°N latitude line.The northern and southern segments were dominated by the East China Sea shelf water(ECSSW)and Kuroshio subsurface water(KSW),respectively.When the KSW(salinity>34)intrusion reached the east of 123°E and south of 31°N,hypoxia zones mainly occurred in the southern segment covered by the Changjiang Diluted Water(CDW),meanwhile the Yellow Sea cold water mass may emerge in the northeastern area.When the KSW intensely invaded westward to the region between 122°and 122.5°E and northward to 31.5°N or further north,hypoxia zones appeared in the northern segment.The strength of the KSW with low dissolved oxygen concentration is the basic driving factor for the hypoxia occurrence in the CE.Moreover,the stratification is crucial for the southern segment,whereas the organic matter decomposition is dominated for the northern segment,even with severe hypoxia across the sea surface in the study area.展开更多
The possibility of preparing cementitious materials by the alkali-activated method using Yellow River sediment(The second largest river in China)as raw material and the modification effect on different slag addition w...The possibility of preparing cementitious materials by the alkali-activated method using Yellow River sediment(The second largest river in China)as raw material and the modification effect on different slag addition were investigated.Sodium silicate and calcium hydroxide were used as the activator,and the specimens were prepared by the press molding method.The hydration process,hydration products,pore characteristics,and mechanical properties were investigated using SEM/EDS,FTIR,TG/DTG,XRD,MIP,and uniaxial compressive strength experiments,respectively.The results showed that the compressive strength of the modified yellow river silt-based cementitious material was significantly increased when the water glass dosage was 12 wt%(Ms=1.8)and the slag dosage was 40%,and its 90-day maximum compressive strength could reach 53 MPa.展开更多
基金supported by the National Key Research and Development Program of China(No.2021YFC3101702)the Pilot Project of Early Warning Monitoring of Hypoxia and Ocean Acidification in the Changjiang Estuary of the Ministry of Natural Resources of China(MNR)(2020-2022)+2 种基金the Key Laboratory of Marine Ecological Monitoring and Restoration Technologies,MNR(No.ME MRT202009)the Key Laboratory of Marine Ecosystem Dynamics,Second Institute of Oceanography,Ministry of Natural Resources(No.MED202005)the Yangtze Delta Estuarine Wetland Ecosystem Observation and Research Station,Ministry of Education&Shanghai Science and Technology Committee(No.ECNU-YDEWS-2020).
文摘The regulating ways of different water masses affecting the locations and intensities of hypoxia zones were studied based on the time-space continuum data from August 2011 to 2013–2017.The 6-year distribution of the hypoxic area in the Changjiang Estuary(CE)and its adjacent waters show that the hypoxic area can be divided into two segments.The southern segment is out of the south branch of the CE,whereas the northern segment is in the junction zone between the South Yellow Sea and the CE.The two segments were divided along the 31.5°–32°N latitude line.The northern and southern segments were dominated by the East China Sea shelf water(ECSSW)and Kuroshio subsurface water(KSW),respectively.When the KSW(salinity>34)intrusion reached the east of 123°E and south of 31°N,hypoxia zones mainly occurred in the southern segment covered by the Changjiang Diluted Water(CDW),meanwhile the Yellow Sea cold water mass may emerge in the northeastern area.When the KSW intensely invaded westward to the region between 122°and 122.5°E and northward to 31.5°N or further north,hypoxia zones appeared in the northern segment.The strength of the KSW with low dissolved oxygen concentration is the basic driving factor for the hypoxia occurrence in the CE.Moreover,the stratification is crucial for the southern segment,whereas the organic matter decomposition is dominated for the northern segment,even with severe hypoxia across the sea surface in the study area.
基金Funded in part by the Joint Funds of National Natural Science Foundation of China(No.U20A20324)National Natural Science Foundation of China(No.51878116)+3 种基金Liaoning Province Key Project of Research and Development Plan(No.2020JH2/10100016)Dalian Science and Technology Innovation Fund Project(No.2020JJ26SN060)the National Natural Science Foundation of China(No.51809109)the National Key Research and Development Projects(No.2017YFC0504506)。
文摘The possibility of preparing cementitious materials by the alkali-activated method using Yellow River sediment(The second largest river in China)as raw material and the modification effect on different slag addition were investigated.Sodium silicate and calcium hydroxide were used as the activator,and the specimens were prepared by the press molding method.The hydration process,hydration products,pore characteristics,and mechanical properties were investigated using SEM/EDS,FTIR,TG/DTG,XRD,MIP,and uniaxial compressive strength experiments,respectively.The results showed that the compressive strength of the modified yellow river silt-based cementitious material was significantly increased when the water glass dosage was 12 wt%(Ms=1.8)and the slag dosage was 40%,and its 90-day maximum compressive strength could reach 53 MPa.
