Is the dinoflagellate Takayama xiamenensis a synonym of Takayama acrotrocha (Kareniaceae, Dinophyceae)?

The naked dinoflagellate Takayama acrotrocha was identified as responsible for a bloom in Shenzhen Bay,Guangdong,China,in early spring 2021.The identification was confirmed by light,scanning,and transmission electron microscopy and molecular data based on the LSU ribosomal DNA(rDNA)and ITS rDNA sequences.This is the first record of T.acrotrocha bloom in the South China Sea.The sulcus of T.acrotrocha was wide and extended onto the epicone as a short intrusion in general,sometime the intrusion was not apparent and some were finger-like.The apical groove was deeply sigmoid.The nucleus was large,ovoid to cup-shaped and occupied most of the epicone.A large,rounded pyrenoid surrounded by a starch sheath was located at the left side to the centre of the hypocone.Under epifluorescence illumination,a row of large vesicular knobs was observed on the upper border of the cingulum.The intraspecific morphological variabilities in the clonal cultures of T.acrotrocha were investigated carefully.Cells that share the same diagnostic characters used for the description of Takayama xiamenensis such as the finger-like sulcus,a large nucleus located in the epicone and the similar pyrenoid type were observed.The LSU rDNA sequences of T.acrotrocha and T.xiamenensis only differed in 3 base pairs(bp)for a sequence length of 673 bp(with a similarity of 99.55%).For these reasons,we propose T.xiamenensis as a junior synonym of T.acrotrocha.

Yangtze River Delta Aerosol liquid water in PM_(2.5)and its roles in secondary aerosol formation at a regional site of Yangtze River Delta

Aerosol liquid water content(ALWC)plays an important role in secondary aerosol formation.In this study,a whole year field campaign was conducted at Shanxi in north Zhejiang Province during 2021.ALWC estimated by ISORROPIA-Ⅱ was then investigated to explore its characteristics and relationship with secondary aerosols.ALWC exhibited a highest value in spring(66.38μg/m^(3)),followed by winter(45.08μg/m^(3)),summer(41.64μg/m^(3)),and autumn(35.01μg/m^(3)),respectively.It was supposed that the secondary inorganic aerosols(SIA)were facilitated under higher ALWC conditions(RH>80%),while the secondary organic species tended to form under lower ALWC levels.Higher RH(>80%)promoted the NO_(3)^(-)formation via gas-particle partitioning,while SO_(4)^(2-)was generated at a relative lower RH(>50%).The ALWC was more sensitive to NO_(3)^(-)(R=0.94)than SO_(4)^(2-)(R=0.90).Thus,the self-amplifying processes between the ALWC and SIA enhanced the particle mass growth.The sensitivity of ALWC and OX(NO_(2)+O_(3))to secondary organic carbon(SOC)varied in different seasons at Shanxi,more sensitive to aqueous-phase reactions(daytime R=0.84;nighttime R=0.54)than photochemical oxidation(daytime R=0.23;nighttime R=0.41)in wintertime with a high level of OX(daytime:130-140μg/m^(3);nighttime:100-140μg/m^(3)).The self-amplifying process of ALWC and SIA and the aqueous-phase formation of SOC will enhance aerosol formation,contributing to air pollution and reduction of visibility.

Study on the fast elimination of smoke particle based on electro-acoustic coupling agglomeration technology

Fire smoke,which consists large amounts of fine particles,is considered as the fatal factor in fires.In this study,a fast smoke particle elimination method based on electro-acoustic coupling agglomeration technology is proposed.First,the experimental results show that the electro-acoustic coupling agglomeration has higher smoke elimination efficiency compared to single-field.The smoke transmission is much less than 80%after 30s of single acoustic or electric field action,while the coupled field reaches 90%.Then,the effects of acoustic frequency,sound pressure level and voltage on the smoke elimination characteristics are discussed.It is found that the optimal acoustic frequency is 1.5kHz.While as the sound pressure level and voltage increase,the elimination efficiency first increases and then tends to stabilize,the critical values of the sound pressure level and voltage are 135 dB and 7kV.This indicates that there is an optimal combination of the three variables.Finally,through the theoretical analysis of particle movement and the micro-morphology of agglomerates,the particle agglomeration mechanism under the electro-acoustic coupling is analyzed.This study provides a new idea for the fast elimination of fire smoke particle.

Detection and Quantification of Water-Soluble Inorganic Chlorine,Bromine and Iodine by MALDI-MS

Halogens are elements in soil and water that occur as organic and inorganic species.Studies have shown that inorganic halogens are closely related to animal and plant life.Matrix-assisted laser desorption/ionization mass spectrometry(MALDI-MS)can achieve high-throughput and rapid analysis,which is also an essential characteristic in some environmental studies.However,there is currently no report on MALDI-MS analysis for water-soluble inorganic halogen compounds.In this study,we aimed to develop a reliable and reproductive method to detect inorganic halogens in soil and water by MALDI-MS.Based on sinapic acid(SA)and silver trifluoromethanesulfonate(SA/AgOTf)as the matrix in negative-ion mode,MALDI-MS showed excellent MS signals related to halogens.Under the optimum conditions,the method achieved satisfactory linearity(R^(2)>0.99)and repeatability(RSD<18%).The LODs for Cl^(−),Br^(−)and I^(−)were 0.76,0.11 and 0.10μg/mL,respectively.The concentration of inorganic halogens from 24 samples was successfully determined by MALDI-MS.In summary,an innovative method was developed for the analysis of inorganic halogens by MALDI-MS using a novel SA/AgOTf matrix,extending the application of MALDI-MS in inorganic compounds.

Non‐chromate conversion process for zinc coating with durable hydrophobicity and enhanced corrosion resistance

A Zn‐based coating with durable hydrophobicity and good corrosion resistance was formed on a mild steel substrate,which involves electroplating Zn from a non‐aqueous electrolyte,followed by passivation in an oleic acid(OA)solution.The electrodeposited Zn coatings were porous,which facilitated the formation of a chemical conversion layer of Zn oleate(ZO)during OA passivation.The Zn coating after passivation had a twolayer structure,which included an outer layer of ZO with a thickness of~26μm and an inner layer of Zn with a thickness of~6μm.The outer layer ZO is a type of metal soap with a smooth surface and durable hydrophobicity,such that water droplets can easily slip off its surface.Corrosion testing and electrochemical measurements in 3.5 wt.%NaCl aqueous solution indicate that the Zn coating after OA passivation exhibits outstanding anti‐corrosion properties compared with those exhibited by pure Zn coating.The corrosion products and mechanism of the two‐layer coating were explored.This study shows that smooth metal oleate coatings can provide hydrophobicity and corrosion resistance simultaneously to mild steel substrates.