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Mechanisms leading to the frequent occurrences of hypoxia and a preliminary analysis of the associated acidification off the Changiiang estuary in summer

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science china Earth sciences 2017年第2期60卷 360-381页

作者： WEI Qinsheng WANG BaoDong YU ZhiGang CHEN JianFang XUE Liang Key Laboratory of marine Chemistry Theory and Technology Ministry of EducationOcean University of ChinaQingdao 266100China First Institute of Oceanography State Oceanic AdministrationQingdao 266061China Laboratory of marine Ecology and Environmental science Qingdao National Laboratory for Marine Science and TechnologyQingdao 266071China second Institute of Oceanography State Oceanic AdministrationHangzhou 310012China

Based on literature data and shipboard observations,this study investigated the main environmental characteristics of the seafloor topography,current field,front,and upwelling that are closely related to hypoxia occurrence off the Changjiang *** physical processes of the plume front and upwelling off the Changjiang estuary in summer were *** vertical distribution pattern of the plume front was closely related to the *** reviewing and analyzing the historical summer hypoxia events off the Changjiang estuary,we statistically demonstrated the spatial structure of the horizontal distribution of the hypoxic zone and investigated the location of occurrence zone of the *** found that the dissolved oxygen(DO)concentration on the inner continental shelf off the estuary showed a"V"shape in relation to station ***,we noted that the hypoxic water on the inner continental shelf mostly occurred on the slopes with steep seafloor *** on the current understanding of the hypoxic mechanisms off the Changjiang estuary,we analyzed the biogeochemical mechanisms that could cause the steep terrain off the Changjiang estuary to become the main areas prone to summer hypoxia and explained the internal relations between the location of the hypoxic zone on the slopes and the plume front and *** plume front and upwelling off the Changjiang estuary and their coupling were important driving forces of summer *** continuous supply of nutrients affected by the interaction of the plume front extension of the Changjiang Diluted Water(CDW)and upwelling and the favorable light conditions were important mechanisms causing the phytoplankton blooms and benthic hypoxia off the Changjiang estuary in *** analyzing oxygen utilization,organic carbon mineralization,and nutrient regeneration in the hypoxic zone,we observed that the significant oxygen utilization process off the Changjiang estuary in summer also mainly occurred near the

关键词： Changjiang estuary Hypoxic zone Upwelling Front Nutrient regeneration Biogeochemistry Acidification

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Concentration level and distribution of polycyclic aromatic hydrocarbons in soil and grass around Mt. Qomolangma, china

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Chinese science Bulletin 2007年第10期52卷 1405-1413页

作者： WANG XiaoPing YAO TanDong CONG ZhiYuan YAN XinLiang KANG shiChang ZHANG Yong Institute of Tibetan Plateau research Chinese Academy of Sciences Beijing 100085 China school of Chemistry and Engineering Shanxi University Taiyuan 030006 China

High mountains may serve as a condenser for persistent organic pollutants. In the present study, soil and grass samples from Mt. Qomolangma region, china were collected from 4600 to 5620 m a.s.l and were analyzed for polycyclic aromatic hydrocarbons (PAHs) to determine if they are concentrated at colder, more elevated sites and to evaluate their possible resources and fractionation. The total PAHs concentration in soil samples was s levels in remote and urban regions. This implied the PAHs levels at Mt. Qomolangma are relatively low and what one might expect in such a remote region of the world. These low values may represent a soil background for mid-latitude Northern Hemisphere soils away from the direct influence of an anthropogenic source. As for the distribution pattern, the low molecular weight PAHs were prone to accumulate at higher altitude, while the high molecular weight PAHs inversely related or unrelated with elevation. Based on high concentration of phenanthrene at elevated sample site and the ratios of individual PAHs, we deduced that home-heating combustion and vehicle emission may result in the constitution trait of PAHs in this mountain region. Monsoon traveling over India, Pakistan and other countries with dense population may carry contaminant to Mt. Qomolangma region.

关键词：中国珠穆朗玛峰周围土壤草地多环芳烃富集浓度分布远距离迁移 PAHs

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Characteristics of nutrients in the Jiulong River and its impact on Xiamen Water, china

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Chinese Journal of Oceanology and Limnology 2013年第5期31卷 1055-1063页

作者：陈宝红暨卫东陈金民林彩黄海宁霍云龙纪贤标 Third Institute of Oceanography State Oceanic Administration College of Information science and Technology Xiamen University

Water samples were collected at 20 sites on 4 occasions in 2009 （twice in May, and once in both August and November） along the Jiulong River, south china to examine how nutrient inputs from the Jiulong River could affect the nutrient status of the Xiamen Water. samples were analyzed for nitrite （NO2-N）, nitrate （NO3-N）, ammonium （NH4-N）, phosphate （PO4-P）, silicate （siO3-si）, salinity, and temperature, to determine the nutrient and trophic status of the river. The results indicate that nutrients are derived mainly from river runoff. NO3-N was the main form of DIN in most parts of the river. In addition, NO3-N, DIN, and siO3-si behave conservatively. There is a surplus of DIN and siO3-si in the river, and PO4-P is a limitation on phytoplankton growth. The concentration of DIN is typically above 0.60 mg/dm3, and higher than 1.00 mg/dm3 in most parts of the river. The concentration of PO4-P is typically above 0.02 mg/dm3, while the concentration of siO3-si is higher than 1.00 rag/din3. Between 2003 and 2008, samples were collected 3 times per year （May, August and November） at 27 sites in the Xiamen Water and analyzed for NO2-N, NO3-N, NH4-N, PO4-P, salinity, and temperature. We discovered that the Jiulong River was the key source of DIN into the Xiamen Water, but not PO4-P, indicating the reason of the N/P molar ratio imbalance in the Xiamen Water. In the future, the effects of high DIN concentrations on the phytoplankton communities and marine ecosystems of the Xiamen Water shall be studied.

关键词： nutrient molar ratio eutrophication N enrichment the Jiulong River

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Isolation and Neuroprotective Activity of Phenolic Derivatives from the marine-Derived Fungus Penicillium janthinellum

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Journal of Ocean University of china 2020年第3期19卷 700-706页

作者： ZHENG Yaoyao CHEN Xu CHEN Lumin sHEN Li FU Xiumei CHEN Qiuxia CHEN Min WANG Changyun marine science&Technology Institute College of Environmental Science&EngineeringYangzhou UniversityYangzhou 225127China Key Laboratory of marine Drugs of Ministry of Education of china School of Medicine and PharmacyOcean University of ChinaQingdao 266003China Laboratory for marine Drugs and Bioproducts Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China Institute of Translational Medicine Medical CollegeYangzhou UniversityYangzhou 225001China Institute of Evolution&marine Biodiversity Ocean University of ChinaQingdao 266003China

A new phenolic compound, 6-(2-acetyl-3,5-dihydroxybenzyl)-4-hydroxy-3-methyl-2H-pyran-2-one(1), along with other six known phenolic derivatives(2-7), were isolated from the mangrove rhizosphere fungus Penicillium janthinellum HK1-6 cultured in potato dextrose broth medium containing 30 g L^(-1) of natural sea salt. The structure of the new compound(1) was elucidated by comprehensive analysis of spectroscopic data including 1D and 2D NMR spectra. The proposed biosynthetic pathway of compound 1 was also studied in this research. Interestingly, a brominated phenolic derivative, aryl bromide(compound 8), was obtained from this fungal strain cultured in medium containing 30 g L^-1 of NaBr instead of natural sea salt. Compound 8 is proposed as a new natural product and formed through bromination of compound 7 when the fungus was cultured with NaBr. The neuroprotective effect of compound 1 on oxygen-glucose deprivation(OGD)-induced injury was investigated in rat spinal cord astrocytes. MTT assay demonstrated that compound 1 can attenuate OGD-induced cell viability loss in rat spinal cord astrocytes.

关键词： marine fungus Penicillium janthinellum phenolic derivative neuroprotective activity

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Mixing processes and patterns of fluids in alkane-CO_(2)-water systems under high temperature and high pressure——Microscopic visual physical thermal simulations and molecular dynamics simulations

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science china Earth sciences 2023年第7期66卷 1622-1646页

作者： Guanghui YUAN shuqi WU Yingchang CAO Zihao JIN Keyu LIU Yanzhong WANG National Key Laboratory of Deep Oil and Gas China University of PetroleumQingdao 266580China Laboratory for marine Mineral Resources Qingdao National Laboratory for Marine Science and TechnologyQingdao 266071China

Various types of geofluids exist in deep and ultra-deep layers in petroliferous *** geofluids are much more active under high-temperature and high-pressure(HTHP)conditions,but their properties are *** simulated the mixing of different fluids in CH_(4)/C_(3)H_(8)/C_(6)H_(14)/C_(8)H_(18)-water systems and C_(6)H_(14)/C_(8)H_(18)-CO_(2)-H_(2)O systems at temperatures of 25℃ to 425℃ and pressures of 5 MPa to 105 MPa,using an in-situ micron quartz capillary tube thermal simulation system and molecular dynamics numerical simulation *** mixing processes,patterns,and mechanisms of various fluids were analyzed at microscale under increasing temperature and pressure *** results show that the miscibility of fluids in the different alkane-H_(2)O and alkane-CO_(2)-H_(2)O systems is not instantaneous,but the miscibility degree between different fluid phases increases as the temperature and pressure rise during the *** physical thermal experiments(PTEs)show that the mixing process can be divided into three stages:initial miscibility,segmented dynamic miscibility,and complete *** molecular dynamics numerical simulations(MDNss)indicate that the mixing process of fluids in the alkane-H_(2)O and alkane CO_(2)-H_(2)O systems can be divided into seven and eight stages,*** carbon number affects the miscibility of alkanes and water,and the temperature and pressure required to reach the same miscibility stage with water increase with the carbon number(C_(3)H_(8),C_(6)H_(14),CH_(4),C_(8)H_(18)).CO_(2) has a critical bridge role in the miscibility of alkanes and water,and its presence significantly reduces the temperatures required to reach the initial,dynamic,and complete miscibility of alkanes and *** results are of great significance for analyzing and understanding the miscibility of geofluids in deep and ultra-deep HTHP systems.

关键词： High temperature high pressure(HTHP) Alkane-H_(2)O-CO_(2)system Mixing of geofluids In-situ visualization thermal experiments Molecular dynamics numerical simulation

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Accurate simulations of pure-viscoacoustic wave propagation in tilted transversely isotropic media

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Petroleum science 2024年第2期21卷 866-884页

作者： Qiang Mao Jian-Ping Huang Xin-Ru Mu Ji-Dong Yang Yu-Jian Zhang Geosciences Department China University of Petroleum(East China)Qingdao266580ShandongChina Pilot National Laboratory for marine science and Technology(Qingdao) Qingdao266207ShandongChina

Forward modeling of seismic wave propagation is crucial for the realization of reverse time migration(RTM) and full waveform inversion(FWI) in attenuating transversely isotropic media. To describe the attenuation and anisotropy properties of subsurface media, the pure-viscoacoustic anisotropic wave equations are established for wavefield simulations, because they can provide clear and stable wavefields. However, due to the use of several approximations in deriving the wave equation and the introduction of a fractional Laplacian approximation in solving the derived equation, the wavefields simulated by the previous pure-viscoacoustic tilted transversely isotropic(TTI) wave equations has low accuracy. To accurately simulate wavefields in media with velocity anisotropy and attenuation anisotropy, we first derive a new pure-viscoacoustic TTI wave equation from the exact complex-valued dispersion formula in viscoelastic vertical transversely isotropic(VTI) media. Then, we present the hybrid finite-difference and low-rank decomposition(HFDLRD) method to accurately solve our proposed pure-viscoacoustic TTI wave equation. Theoretical analysis and numerical examples suggest that our pure-viscoacoustic TTI wave equation has higher accuracy than previous pure-viscoacoustic TTI wave equations in describing q P-wave kinematic and attenuation characteristics. Additionally, the numerical experiment in a simple two-layer model shows that the HFDLRD technique outperforms the hybrid finite-difference and pseudo-spectral(HFDPs) method in terms of accuracy of wavefield modeling.

关键词： Pure-viscoacoustic TTI wave equation Attenuation anisotropy seismic modeling Low-rank decomposition method

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Optimization of shanghai marine Environmental Monitoring sites in the Identification of Boundaries of Different Water Quality Grades

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Journal of Ocean University of china 2018年第4期17卷 846-854页

作者： FAN Haimei GAO Bingbo WANG Jinfeng QIN Xiaoguang LIU Pengxia HU Maogui XU Peng East china sea Environmental Monitoring Center State Oceanic AdministrationShanghai 201206China Beijing research Center for Information Technology in Agricultur Beijing Academy of Agriculture and Forestry SciencesBeijing 100097China state Key Laboratory of Resources&Environmental Information system Institute of Geographic Sciences&Nature Resources ResearchChinese Academy of SciencesBeijing 1O0101China

Water quality is critical to ensure that marine resources and the environment are utilized in a sustainable manner. The objective of this study is therefore to investigate the optimum placement of marine environmental monitoring sites to monitor water quality in shanghai, china. To improve the mapping or estimation accuracy of the areas with different water quality grades, the monitoring sites were fixed in transition bands between areas of different grades rather than in other positions. Following bidirectional optimization method, first, 18 candidate sites were selected by filtering out specific site categories. second, three of these were, in turn, eliminated because of the rule defined by the changes in the areas of water quality grades and by the standard deviation of the interpolation errors of dissolved inorganic nitrogen(DIN) and phosphate(PO_4-P). Furthermore, indicator kriging was employed to depict the transition bands between different water quality grades whenever new sampling sites were added. The four optimization projects of the newly added sites reveal that, all optimized sites were distributed in the transition bands of different water grades, and at the same time in the areas where the historical sites were sparsely distributed. New sites were also found in the overlap region of different transition bands. Additional sites were especially required in these regions to discriminate the boundaries of different water quality grades. Using the bidirectional optimization method of the monitoring sites, the boundaries of different water quality grades could be determined with a higher precision. As a result, the interpolation errors of DIN and PO_4-P could theoretically decrease.

关键词： bidirectional optimization method boundaries of water quality grades Changjiang River Estuary and its adjacent areas transition bands indicator kriging

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Contributions of the Bering strait throughflow to oceanic meridional heat transport under modern and Last Glacial Maximum climate conditions

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Journal of Oceanology and Limnology 2019年第2期37卷 398-409页

作者： ZHANG Cunjie LIN Xiaopei Physical Oceanography Laboratory/CIMsT Ocean University of China and Qingdao National Laboratory for Marine Science and Technology

Paleo reconstructions and model simulations have suggested the Bering strait plays a pivotal role in climate change. However, the contribution of the Bering strait throughflow to oceanic meridional heat transport (OMHT) is about 100 times smaller than the OMHT at low latitudes in the modern climate and it is generally ignored. Based on model simulations under modern and Last Glacial Maximum (LGM,~21 ka;ka=thousand years ago) climate conditions, this study highlights the importance of the Bering strait throughflow to OMHT. The interbasin OMHT induced by the Bering strait throughflow is estimated by interbasin-intrabasin decomposition. similar to barotropic-baroclinic-horizontal decomposition, we assume the nonzero net mass transport induced by interbasin throughflows is uniform across the entire section, and the interbasin term is separated to force zero net mass transport for the intrabasin term. Based on interbasinintrabasin decomposition, the contribution of the Bering strait throughflow is determined as ~0.02 PW (1 PW=10 15 W) under the modern climate, and zero under the LGM climate because the closed Bering strait blocked interbasin throughflows. The contribution of the Bering strait throughflow to OMHT is rather small, consistent with previous studies. However, comparisons of OMHT under modern and LGM climate conditions indicate the mean absolute changes are typically 0.05 and 0.20 PWin the North Atlantic and North Pacific, respectively. Thus, the contribution of the Bering strait throughflow should not be ignored when comparing OMHT under diff erent climate conditions.

关键词： oceanic meridional heat transport (OMHT) Bering strait throughflow Last Glacial Maximum (LGM)

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Microbiota characteristics in sebastes schlegelii intestine in early life stages

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Journal of Oceanology and Limnology 2020年第1期38卷 275-287,I0019-I0025页

作者： JIANG Yan LIU Xuezhou XU Yongjiang sHI Bao WANG Bin Key Laboratory of sustainable Development of marine Fisheries Ministry of Agriculture and Rural Aff airsYellow Sea Fisheries Research InstituteChinese Academy of Fishery SciencesQingdao 266071China Laboratory for marine Fisheries and Food Production Processes Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China

The structure of intestinal microbiota of black rockfish sebastes schlegelii in five early development stages were determined in high throughput sequencing with Illumina Miseq PE300 *** relationship between intestinal microbial community and the environmental(including culture water and feed)microbiota and the abundance variation trends of core microbiota were investigated,based on which the source of some core microbiota was analyzed in this *** results show that Proteobacteria and Firmicutes are the most dominant phyla in *** the genus level,there are obvious differences between the artificial breeding fish and wild adults in the intestinal microflora *** compositions of dominant genera are similar,although the structure of intestinal microbiota gradually changes with the growth of larvae and *** core microbiota including Bacillus,Acinetobacter,Pseudomonas,Lactobacillus,Lactococcus,Glaciecola,Vibrio,Pseudoalteromonas,Acidovorax,and Aliivibrio were determined in the analysis of dominant and shared *** with the water,the effect of feed microbiota on the structure of the gut microbial community is more ***,the trends of Bacillus,Acinetobacter,Pseudomonas,Lactobacillus,Lactococcus,and Glaciecola were opposite to Vibrio and Pseudoalteromonas in the *** correlation analysis suggested that Acidovorax,Glaciecola,Pseudomonas,Lactobacillus,and Acinetobacter might transited from mainly the parents and/or came from the fertilization *** relative results may provide a theoretical reference for selecting the native probiotics,and supply the basic data for artificially regulating the intestinal microbiota with probiotic during early developmental stage of black rockfish.

关键词： core microbiota correlation analysis intestinal microbiota larva and juvenile microbiota structure sebastes schlegelii

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Two drifting paths of sargassum bloom in the Yellow sea and East china sea during 2019-2020

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Acta Oceanologica sinica 2022年第6期41卷 78-87页

作者： Chao Yuan Jie Xiao Xuelei Zhang Mingzhu Fu Zongling Wang The MNR Key Laboratory of marine Eco-Environmental science and Technology First Institute of OceanographyMinistry of Natural ResourcesQingdao 266061China Laboratory of marine Ecology and Environmental science Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China National Engineering Laboratory for Integrated Aero-space-Ground-Ocean Big Data Application Technology Xi'an 710129China

The macroalgal blooms of floating brown algae sargassum horneri are increasing in the Yellow sea and East china sea during the past few ***,the annual pattern of sargassum bloom is not well *** study the developing pattern and explore the impacts from hydro-meteorologic environment,high resolution satellite imageries were used to monitor the distribution,coverage and drifting of the pelagic sargassum rafts in the Yellow sea and East china sea from september 2019 to August *** blooms were detected from October 2019 to June 2020 and presented two successive drifting paths that both initiated from around 37°*** first path spanned smaller spatial scale and shorter period,starting with a bloom of 3 km^(2) distribution area near the eastern tip of shandong Peninsula in late October 2019 and drifted southwards,hit the Pyropia aquaculture area in early January 2020,then vanished in the northwest of East china sea(ca.32°N)around end of *** second path began with a large distribution area of 23000 km^(2) east of 123°E in late January 2020,firstly moved southwards in the central Yellow sea and northern East china sea(north of 29°N)till late April,then turned northwards with monsoon wind and vanished from late June to *** mean sea surface temperature of 8℃ to 20℃ in the sargassum bloom areas corresponded to in situ observed temperature range for vegetative growth and floating of *** was no observed floating sargassum blooms during July through september in the Yellow sea and East china *** results indicate that floating *** is unable to complete life cycle in the Yellow sea and East china sea,and provide insights to the future management of sargassum *** studies are needed to validate the pattern and source of annual sargassum bloom in the Yellow sea and East china sea.

关键词： sargassum horneri macroalgal bloom high resolution remote sensing wind directions sea surface temperature Yellow sea and East china sea

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