Alexandrium blooms in the northwest area of the Bohai Sea(Qinhuangdao coastal area),China,produce large amounts of toxins that could be enriched in shellfish and consequently harm human bodies.To understand the succes...Alexandrium blooms in the northwest area of the Bohai Sea(Qinhuangdao coastal area),China,produce large amounts of toxins that could be enriched in shellfish and consequently harm human bodies.To understand the succession of the phytoplankton community structure during Alexandrium bloom events in the northwest area of the Bohai Sea off Qinhuangdao from April 2 to May 7,2019,microscopy observations and high-performance chromatography(HPLC)-pigment analysis were performed.Sixty species of phytoplankton were identified,mainly diatoms and dinofl agellates.The abundance of Alexandrium reached the maximum on April 16(3.3×10^(3) cells/L).HPLC-pigment CHEMTAX analysis showed that the phytoplankton community was composed mainly of diatoms,dinofl agellates,prasinophytes,and cryptophytes.Diatoms were the main contributor to the total Chl-a pool.There was a downward trend for the proportion of diatom biomass to the total Chl-a pool,followed by an upward trend.The proportion of dinoflagellate biomass showed the opposite trend,whereas that of the prasinophyte biomass presented an obvious increasing trend.Temperature,nutrients,and nutrient structures were the main factors on the distribution of different phytoplankton groups in the study area as shown in the redundancy analysis.This work illustrates the succession of phytoplankton community structures during Alexandrium blooms and provided a theoretical basis for studies on the mechanism underlying the outbreak of harmful algal blooms in sea areas.展开更多
Chinese town worker endowment insurance system of the combination of The social pooling and individual account worked nearly 20 years, in the process of implementing the system have some problems such as the pressure ...Chinese town worker endowment insurance system of the combination of The social pooling and individual account worked nearly 20 years, in the process of implementing the system have some problems such as the pressure pension payments, large number of outstanding transition costs, unclear property fights and individual account “empty” and so on. Because China＇ s capital market is not mature at the same time, lead to the real personal accounts funds also difficult to achieve their value. To solve this problem, on the basis of analyzing the necessity and feasibility of the nominal account system, summed up the after proper deformation and transformation, the “nominal account” is a transitional system arrangement for an alternative.展开更多
Placing metals within microwave ovens has been generally viewed as a dangerous practice because of occurrence of violent discharge,but in recent years such discharge phenomenon has attracted increasing attention and h...Placing metals within microwave ovens has been generally viewed as a dangerous practice because of occurrence of violent discharge,but in recent years such discharge phenomenon has attracted increasing attention and has enabled a variety of exciting applications.In this work,we provide a comprehensive review of fundamental understanding of microwave-metal discharge interaction and its state-of-the-art application for nanomaterials synthesis.We introduce the microscopic interaction between different categories of materials and the electric and magnetic field of microwaves.For microwave-metal interaction,we highlight its size-dependence and point out the influence of the oxide layer on the surface of metals.We discuss the required conditions for occurrence of discharge,microscopic formation mechanism,and characteristic features of microwave-metal discharge processes.Through analyzing the influence from the microwave input,discharging metals,and surrounding discharging media,we discuss the strategy for systematical regulation of the discharge process.We describe the applications of the microwave-metal discharge for facile synthesis of various functional nanomaterials including core-shell carbon/metal,metal oxides,metal chalcogenides,intermetallic compounds,metallic nanoparticles and metallic compounds,and organic compounds.Finally,the challenges in precise characterization and dynamic regulation of the discharge process as well as exciting application opportunities are discussed.展开更多
基金Supported by the Special Research for the Science and Technology Basic Resources Investigation Program of China(No.2018FY100200)the National Natural Science Foundation of China(Nos.31772075,32072329)the Project of Jiangsu Natural Science Foundation of China(No.BK20171262)。
文摘Alexandrium blooms in the northwest area of the Bohai Sea(Qinhuangdao coastal area),China,produce large amounts of toxins that could be enriched in shellfish and consequently harm human bodies.To understand the succession of the phytoplankton community structure during Alexandrium bloom events in the northwest area of the Bohai Sea off Qinhuangdao from April 2 to May 7,2019,microscopy observations and high-performance chromatography(HPLC)-pigment analysis were performed.Sixty species of phytoplankton were identified,mainly diatoms and dinofl agellates.The abundance of Alexandrium reached the maximum on April 16(3.3×10^(3) cells/L).HPLC-pigment CHEMTAX analysis showed that the phytoplankton community was composed mainly of diatoms,dinofl agellates,prasinophytes,and cryptophytes.Diatoms were the main contributor to the total Chl-a pool.There was a downward trend for the proportion of diatom biomass to the total Chl-a pool,followed by an upward trend.The proportion of dinoflagellate biomass showed the opposite trend,whereas that of the prasinophyte biomass presented an obvious increasing trend.Temperature,nutrients,and nutrient structures were the main factors on the distribution of different phytoplankton groups in the study area as shown in the redundancy analysis.This work illustrates the succession of phytoplankton community structures during Alexandrium blooms and provided a theoretical basis for studies on the mechanism underlying the outbreak of harmful algal blooms in sea areas.
文摘Chinese town worker endowment insurance system of the combination of The social pooling and individual account worked nearly 20 years, in the process of implementing the system have some problems such as the pressure pension payments, large number of outstanding transition costs, unclear property fights and individual account “empty” and so on. Because China＇ s capital market is not mature at the same time, lead to the real personal accounts funds also difficult to achieve their value. To solve this problem, on the basis of analyzing the necessity and feasibility of the nominal account system, summed up the after proper deformation and transformation, the “nominal account” is a transitional system arrangement for an alternative.
基金supported by the National Key Research and Development Project from Ministry of Science and Technology of China(No.2022YFA1203100)Innovation Program of Shanghai Municipal Education Commission(No.2019-01-07-00-02-E00069)+1 种基金the National Natural Science Foundation of China(No.51873105)the Top Young Talents of Ten Thousand Talents Plan.
文摘Placing metals within microwave ovens has been generally viewed as a dangerous practice because of occurrence of violent discharge,but in recent years such discharge phenomenon has attracted increasing attention and has enabled a variety of exciting applications.In this work,we provide a comprehensive review of fundamental understanding of microwave-metal discharge interaction and its state-of-the-art application for nanomaterials synthesis.We introduce the microscopic interaction between different categories of materials and the electric and magnetic field of microwaves.For microwave-metal interaction,we highlight its size-dependence and point out the influence of the oxide layer on the surface of metals.We discuss the required conditions for occurrence of discharge,microscopic formation mechanism,and characteristic features of microwave-metal discharge processes.Through analyzing the influence from the microwave input,discharging metals,and surrounding discharging media,we discuss the strategy for systematical regulation of the discharge process.We describe the applications of the microwave-metal discharge for facile synthesis of various functional nanomaterials including core-shell carbon/metal,metal oxides,metal chalcogenides,intermetallic compounds,metallic nanoparticles and metallic compounds,and organic compounds.Finally,the challenges in precise characterization and dynamic regulation of the discharge process as well as exciting application opportunities are discussed.
