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Sexual reproduction and short-term fitness advantage in the rotifer Brachionus calyciflorus:implications for the coexistence of sympatric clones

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Chinese Journal of Oceanology and Limnology 2013年第5期31卷 987-993页

作者：孙栋马蕊刘玮牛翠娟 Ministry of Education key {1. for Biodiversity Science and Ecological Engineering College of Life Sciences Beijing Normal University laboratory of {1. Ecosystem and Biogeochemistry Second Institute of Oceanography SOA Beijing No. 5 High School Research Center for marine Ecology First Institute of Oceanography SOA

Large numbers of rotifer eggs from sediment resting egg banks may hatch simultaneously under appropriate conditions; therefore, natural populations are likely to be multiclonal in a growing season. A recent field investigation showed that subordinate and ephemeral clones were able to establish populations in an environment with several strongly dominant clone populations. However, it was not clear how the subordinate populations maintained their growth under these conditions where the crowding signal would induce high levels of sexual reproduction in the dominant clone populations. In the present study, we conducted a continuous passage to 60 generations for new populations at three different temperatures （1.~C, 25~C, and 35~C）. These populations emerged from resting eggs produced by a clone population. At the first, 30th, and 60th generations, the populations were sampled and fitness was assayed using the life-table method. We found a significant short-term fitness advantage for populations newly emerged from resting eggs produced by a clone population of the rotifer Brachionus calycifiorus, followed by a significant decrease in relative fitness with long-term continuous passage. Our results suggested that the early short- term fitness advantage was important for later-hatched and subordinate clone populations in an environment with multiple sympatric clones. The early short-term fitness might also promote the coexistence of sympatric clones because it could help to offset the cost of early sexual reproduction.

关键词： sexual reproduction cyclical parthenogenesis Brachionus calyciflorus coexistence fitness advantage

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Vertical distribution characteristics of PM in the surface layer of Guangzhou

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Particuology 2015年第3期13卷 3-9页

作者： Xuejiao Deng Fei Li Yuanhong Li Jianyong Li Hongzhi Huang Xiantong Liu Institute of Tropical and marine Meteorology/Guangdong Provincial {1. laboratory of Regional Numerical Weather Prediction China Meteorological Administration(CMA) Guangdong Atmosphere Sounds Technology Centre

Measurements of particulate matter （PM）, i.e., PM1., PM2.5, and PM1. have been performed on the Can- ton Tower, a landmark building in Guangzhou, at heights of 1.1.and 454 m since November 201., using a GRIMM 1.0 aerosol particle spectrometer （Germany）. Analyses of data from November 201. to May 201. showed that the annual average values of PM1., PM2.5, and PM 1.at the observation height of 1.1.m above the ground were 44.1. 38,2, and 34.9 μg/m3, respectively, and those at 454m above the ground were 35.7, 30,4, and 27.5 μg/m3, respectively. By considering the values of the secondary concentration limits given in the Ambient Air Quality Standards issued in 201., it was observed that the annual average values of PM1. at the observation heights of 1.1.and 454 m, as well as those of PM2.5 at 454 m, reached those standards. Furthermore, the over-standard amplitude of the annual average value of PM2.5 at the observation height of 1.1.m was 9.1.. During the observation period, the maximum daily average val- ues of PM1., PM2.5, and PMI at the observation height of 1.1.m were 1.3.3, 1.4.8, and 1.3.8 μg/m3, respectively, and those at 454 m were 1.2.8, 92.7, and 86.4 μg/m3. The daily average values of PM1. at the observation height of 454 m were not above the standards. The over-standard frequencies of the daily average values of PM1. and PM2.5 at the observation height of 1.1.m were 0.6% and 1.,7% respectively, and the over-standard amplitudes were 9.0% and 24.4%, respectively. The over-standard frequency of the daily average value of PM2.5 at the observation height of 454 m was 2.0%, and the over-standard amplitude was 1..4%. Accordingly, it can be stated that the air at the observation height 454 m above the ground did not reach the secondary limit of the new standards. The pollution was most serious during winter, and the air was relatively cleaner during summer, Overall, the vertical distributions of PM1., PM2.5, and PMI decreased with height. The lapse rates showed the fo

关键词： PM1.PM2.5PM1.ver-standardVertical distributionSurface layer

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How does Mei-yu precipitation respond to climate change?

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National Science Review 2023年第12期10卷 137-149页

作者： Bo Sun Rufan Xue Wanling Li Siyu Zhou Huixin Li Botao Zhou Huijun Wang Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Key Laboratory of Meteorological Disasters Ministry of EducationJoint International Research Laboratory of Climate and Environment ChangeNanjing University of Information Science and Technology Southern marine Science and Engineering Guangdong {1.(Zhuhai) Nansen Zhu International Research Centre Institute of Atmospheric PhysicsChinese Academy of Sciences

Mei-yu is an important weather phenomenon in the middle-lower Yangtze River valley(YRV) *** study investigates the changes in the characteristics of Mei-yu under global warming and the potential reasons based on observation and reanalysis data during 1.61.2022. Notable increasing long-term trends are detected in the number of days without rainfall(NDWOR), the intensity of rainfall events, and the frequency and intensity of extreme precipitation events(EPEs) in the YRV region during the Mei-yu period(1. June–1. July) over past decades. The increasing trend in NDWOR is attributed to decreased relative humidity over land surface and a longer time for the air to be replenished with moisture after rainfall events in a warming climate. The increasing trends in the intensity of rainfall events and frequency/intensity of EPEs are attributed to the strengthened transient water vapor convergence and convection in the atmosphere under global warming. Furthermore, the response of Mei-yu to 2°C of global warming with respect to the pre-industrial climate is analysed using CMIP6 models. The results suggest that the NDWOR,intensity of rainfall events and frequency of EPEs will increase in the YRV region during the Mei-yu period under the 2°C warming scenario, which implies a more challenging climate risk management in the ***, the intensity of rainfall events during the Mei-yu period has the most significant response to climate change in observations and projections. The model results have a relatively large uncertainty.

关键词： Mei-yu extreme precipitation events days without rainfall water vapor 2°C warming scenario

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Design and multistability analysis of five-value memristor-based chaotic system with hidden attractors

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Chinese Physics B 2021年第10期30卷 207-218页

作者： Li-Lian Huang Shuai Liu Jian-Hong Xiang Lin-Yu Wang College of Information and Communication Engineering Harbin Engineering UniversityHarbin 150001China MIIT key {1. of Advanced marine Communication and Information Technology Harbin 150001China

A five-value memristor model is proposed,it is proved that the model has a typical hysteresis loop by analyzing the relationship between voltage and ***,based on the classical Liu-Chen system,a new memristor-based fourdimensional(4D)chaotic system is designed by using the five-value *** trajectory phase diagram,Poincare mapping,bifurcation diagram,and Lyapunov exponent spectrum are drawn by numerical *** is found that,in addition to the general chaos characteristics,the system has some special phenomena,such as hidden homogenous multistabilities,hidden heterogeneous multistabilities,and hidden ***,according to the dimensionless equation of the system,the circuit model of the system is built and *** results are consistent with the numerical simulation results,which proves the physical realizability of the five-value memristor-based chaotic system proposed in this paper.

关键词： five-valued memristor chaotic system hidden attractor multistability

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Internal Facies Architecture and Evolution History of Changxing Mouth-Bar Complex in the Changjiang(Yangtze)Delta,China

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Journal of Ocean University of China 2018年第6期17卷 1281-1289页

作者： SU Jianfeng FAN Daidu State key {1. of marine Geology Tongji UniversityShanghai 200092China State key {1. of Estuarine and Coastal Research Shanghai 200062China School of Geoscience Yangtze UniversityWuhan 430100China

River-mouth bar is a fundamental element to constitute a delta system, and its internal facies architectures are vital to reconstruct delta evolution history and study high-resolution sequence stratigraphy. Changxing Island is a representative mouth-bar complex in the modern Changjiang Delta. Its vertical stacked strata produced by delta progradation were first studied by detailed facies analysis of core CX03, and then a general facies architecture and evolution history of mouth-bar complexes in the modern Changjiang Delta were discussed through a comparative study of 5 different cores and historical charts. A progradational deltaic sequence has generally a similar internal facies architecture, composed of massive muddy deposits of prodelta and delta-front slope facies at the bottom, sand-dominated deposits of delta-front platform, inter-bar channel and mouth-bar facies at the middle, and heterolithic deposits of tidal flat and saltmarsh facies at the top. There is a significant time lag for the initial formation of channel-mouth bar systems between Chongming and Jiuduansha Islands. Compared with subtidal flats, sedimentation rates on intertidal flats were highly accelerated, potentially resulting from weakening wave and tidal strength over extensive intertidal flats and increasing human embankment activities in the last few centuries. These findings provide some new clues to understand modern and ancient mouth-bar evolution and resultant sequence strata in tide-dominated deltas.

关键词： Changxing Island Changjiang Delta river-mouth bar tide dominated sedimentary facies facies architecture delta evolution

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Variations of pore water sulfate gradients in sediments as indicator for underlying gas hydrate in Shenhu Area, the South China Sea

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Science China Earth Sciences 2013年第3期56卷 530-540页

作者： WU LuShan YANG ShengXiong LIANG JinQiang SU Xin FU ShaoYing SHA ZhiBin YANG Tao School of marine Geosciences China University of Geosciences Guangzhou marine Geological Survey State key {1. for Mineral Deposits Research Center for Marine Geochemistry Research Nanjing University

Shenhu Area is one of the most promising areas for gas hydrate exploration in the northern South China Sea （SCS）. Pore water sulfate gradient, sulfate-methane interface （SMI） depth, and sulfate flux were analyzed at 53 sites in this area. SO42- gradient ranges between 0.33 and 4.43 mmol L-L m-1. SMI depths are from 7.7 to 87.9 mbsf. Sulfate flux varies between 2.0 and 26.9 mmol m-2 yr L, with a mean of 1..7 mmol m-2 yr1. Correlation coefficient between SMI depth and methane flux for the 53 sites is -0.80, implying that methane flux regulates the rate of anaerobic methane oxidation （AMO）, SMI depth, and sulfate flux. Twelve anomalous fields with high methane flux and steep sulfate gradients were recognized. Bottom simulating reflector （BSR） is distributed mainly in areas where SMI depth is less than 50 mbsf or places with sulfate flux larger than 3.5 mmol m-2 yr-1. It is suggested that the Baiyun Sag and the Southern Uplift are potential areas for gas hydrate exploration.

关键词： sulfate gradient SMI sulfate flux BSR gas hydrates Shenhu Area

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Modeling calving process of glacier with dilated polyhedral discrete element method

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Acta Oceanologica Sinica 2021年第7期40卷 159-169页

作者： Lu Liu Ji Li Qizhen Sun Chunhua Li Sue Cook Shunying Ji State key {1. of Structural Analysis for Industrial Equipment Dalian University of TechnologyDalian 116024China National marine {1.al Forecasting Center Beijing 100081China Institute for marine and Antarctic Studies University of TasmaniaHobart 7001Australia

Mass loss caused by glacier calving is one of the direct contributors to global sea level *** calving laws are required for accurate modelling of ice sheet mass *** continuous and discontinuous methods have been used for glacial calving *** this study,the discrete element method(DEM)based on dilated polyhedral elements is introduced to simulate the calving process of a tidewater *** polyhedrons can be obtained from the Minkowski sum of a sphere and a core *** elements can be utilized to generate a continuum ice material,where the interaction force between adjacent elements is modeled by constructing bonds at the joints of the common faces.A hybrid fracture model considering fracture energy is *** viscous creep behavior of glaciers on long-term scales is not *** applying buoyancy and gravity to the modelled glacier,DEM results show that the calving process is caused by cracks which are initialized at the top of the glacier and spread to the *** results demonstrate the feasibility of using the dilated polyhedral DEM method in glacier simulations,additionally allowing the fragment size of the breaking fragments to be *** relationship between crack propagation and internal stress in the glacier is analyzed during calving *** the analysis of the Mises stress and the normal stress between the elements,it is found that geometric changes caused by the glacier calving lead to the redistribution of the *** tensile stress between the elements is the main influencing factor of glacier ice *** addition,the element shape,glacier base friction and buoyancy are studied,the results show that the glacier model based on the dilated polyhedral DEM is sensitive to the above conditions.

关键词： glacier calving discrete element method dilated polyhedral element bond and fracture model

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Effects of used lubricating oil on two mangroves Aegiceras corniculatum and Avicennia marina

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Journal of environmental Sciences 2007年第11期19卷 1355-1360页

作者： YE Yong TAM N FY State key {1. of marine environmental Science Xiamen University Xiamen 361005 China Department of Biology and Chemistry City University of Hong Kong Hong Kong China

An outdoor experiment was set up to investigate the effects of used lubricating oil （5 L/m^2） on Aegiceras corniculatum Blanco. and Avicennia marina （Forsk） Vierh., two salt-excreting mangroves. A. marina was more sensitive to used lubricating oil than A. corniculatum and canopy-oiling resulted in more direct physical damage and stronger lethal effects than base-oiling. When treated with canopy-oiling, half of A. corniculatum plants survived for the whole treatment time （90 d）; but, for A. marina, high mortality （83%） resulted from canopy-oiling within 3 weeks and no plants survived for 80 d. Base-oiling had no lethal effects on A. corniculatum plants even at the termination of this experiment, but 83% of A. marina plants died 80 d after treatment. Forty days after canopyoiling, 93% ofA. corniculatum leaves fell and no live leaves remained on A. marina plants. By the end of the experiment, base-oiling treatment resulted in about 45% ofA. corniculatum leaves falling, while all A. mar/na leaves and buds were burned to die. Lubricating oil resulted in physiological damage to A. corniculatum leaves, including decreases in chlorophyll and carotenoid contents, nitrate reductase, peroxidase and superoxide dismutase activities, and increases in malonaldehyde contents. For both species, oil pollution significantly reduced leaf, root, and total biomass, but did not significantly affect stem biomass. oil pollution resulted in damage to the xylem vessels of fine roots but not to those of mediate roots.

关键词： used lubricating oil mangrove Aegiceras corniculatum Avicennia marina

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Modified gelatin with quaternary ammonium salts containing epoxide groups

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Chinese Chemical Letters 2014年第8期25卷 1193-1197页

作者： Ya-Ming Liu Xiao Cui Chuan-Ming Hao Fu-Rong Tao Jun-Ying Li Shandong Provincial key {1. of Fine Chemicals Qilu University of Technology School of marine Science and Engineering Tianjin University of Science and Technology

An EPDDMAC-GE polymer （hydrophilic molecule） has been synthesized based on epoxypropyl dodecyl dimethyl ammonium chloride （EPDDMAC） and gelatin. A DEEPSAC-GE polymer （hydrophobic molecule） has been synthesized based on diethyl-2,3-epoxypropyl-[3-methyldimethoxyl] silpropyl ammonium chloride （DEEPSAC） and gelatin. Compared with initial gelatin, the gelatin modified with quaternary ammonium salts containing epoxide groups exhibits stronger antibacterial activity.

关键词： Quaternary ammonium salts Epoxide group Gelatin Modified

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Late Eocene–early Miocene provenance evolution of the Crocker Fan in the southern South China Sea

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Acta Oceanologica Sinica 2023年第3期42卷 215-226页

作者： Yuchi Cui Lei Shao Wu Tang Peijun Qiao Goh Thian Lai Yongjian Yao State key {1. of marine Geology Tongji UniversityShanghai 200092China Earth Dynamics Research Group The Institute for Geoscience Research(TIGeR)School of Earth and Planetary SciencesCurtin UniversityGPO Box U1987Australia China National Offshore oil Corporation(CNOOC)Research Institute Co. Ltd.Beijing 100028China Department of Earth Sciences and environment Faculty of Science and TechnologyUniversity Kebangsaan MalaysiaBangi 43600SelangorMalaysia Guangzhou marine Geological Survey Ministry of Natural ResourcesGuangzhou 510075China

There are many large-scale Cenozoic sedimentary basins with plentiful river deltas,deep-water fans and carbonate platforms in the southern South China *** Crocker Fan was deposited as a typical submarine fan during the late Eocene–early Miocene,and stretches extensively across the entire Sarawak–Sabah of the northern Borneo ***,systematic analyses are still lacking regarding its sediment composition and potential source *** consensus has been reached yet on the provenance evolution and sedimentary infilling processes,which seriously impeded the {1.-and-gas exploration *** combining with sedimentaryfacies identification,heavy mineral assemblages,elemental geochemistry and detrital zircon U-Pb dating,this paper aims to generalize an integrated analysis on the potential provenance terranes and restore source-to-sink pathways of the Crocker *** general,the Crocker Fan was initially formed over the Cretaceous–lower/middle Eocene Rajang Group by an angular Rajang *** continual southward subduction of the protoSouth China Sea resulted in magmatic activities and subsequent regional deformation and thrusting along the Lupar Line in the northern *** lowermost Crocker sequence is featured by a thick conglomerate layer sourced from in-situ or adjacent *** the late Eocene to the early Miocene,the Crocker Fan was constantly delivered with voluminous detritus from the Malay Peninsula of the western *** Zengmu Basin was widely deposited with delta plain and neritic facies sediments,while the Brunei-Sabah Basin,to the farther east,was ubiquitously characterized by turbiditic *** Crocker Fan successions are overall thick layers of modest-grained sandstones,which formed high-quality reservoirs in the southern South China Sea region.

关键词： source-to-sink analysis zircon U-Pb age submarine fan Malay Peninsula southern South China Sea

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