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DIATOM COMMUNITY SUCCESSION AND NUTRIENT EVOLUTION RECORDED FROM A sediment CORE OF THE LONGGAN lake, A LARGE SHALLOW lake IN EAST china

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水生生物学报 2006年第6期30卷 702-710页

作者： DONG Xu-Hui and YANG xiang-Dong (nanjing {2. of Geography & limnology, the chinese academy of sciences, nanjing 210008, china) nanjing institute of Geography & {2. the Chinese Academy of Sciences Nanjing 210008

The Longgan lake is a shallow mesotrophic macrophyte-dominated lake. According to the high-resolution diatom research from its {2. core, the diatom community succession was built, and the total phosphorus (TP) and chlorophyll-a (Chl-a) concentration were quantitatively reconstructed for the past 2.00 years, based on the diatom-TP and diatom-Chla transfer functions. The shifts of diatom assemblages also mirrored the developments of aquatic plant, reflecting the characters of aquatic ecosystem evolution. The inferred epilimnetic TP concentration fluctuated within a small range of 36 to 62.g/L, indicating the lake remained a relative stable mesotrophic status in the long historical period. The periodical variations of the diatom assemblage and trophic status suggest a mitigating function of shallow macrophyte-dominated lakes to nutrient input. The changes of lakes’ trophic status don’t linearly respond to the human disturbance in the catchment. The dynamics mechanism of phosphorus in macrophyte-dominated lakes, as inferred from diatoms, will provide a scientific foundation for the prediction of trophic status change in a shallow lake, as well as the lake ecological restoration and management decisions.

关键词： Diatom assemblage Nutrient Quantitative reconstruction Aquatic macrophyte Longgan lake

Organic Phosphorus in Shallow lake sediments in Middle and Lower Reaches of the Yangtze River Area in {2.

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Pedosphere 2008年第3期18卷 394-400页

作者： JIN xiang-Can WANG Sheng-Rui CHU Jian-Zhou WU Feng-Chang State environmental Protection Key laboratory for {2. Pollution Control Research Center of Lake Eco-EnvironmentChinese Research Academy of Environmental Sciences Beijing 100012 （China） Colleges of Resource and environment Hebei Agriculture University Baoding 071001 （China） State Key laboratory of environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang550002 （China）

Thirteen sediment core samples(0-10 cm) were taken from the seven lakes in the middle and lower reaches of the Yangtze River to determine the contents and distributions of organic phosphorus(P) fractions in the sediments of the shallow lakes in the *** organic P fractions in the sediments were in the order of moderately labile organic P(MLOP) > moderately resistant organic P(MROP) > highly resistant organic P(HROP) > labile organic P(LOP),with average proportional ratios of 13.2.2.8:1.3:***,MLOP,and MROP were significantly related to the contents of total organic carbon(TOC),water-soluble P(WSP),algal-available P(AAP),NaHCO3-extractable P(Olsen-P),total P(TP),organic P(OP),and inorganic P(IP).However,HROP was significantly related to OP and weakly correlated with TOC,WSP,AAP,Olsen-P,TP or *** suggested that organic P,especially LOP and MLOP in sediments,deserved even greater attention than IP in regards to lake *** terms of organic P,sediments were more hazardous than soils in lake *** OP concentrations were higher in moderately polluted sediment than those in heavily polluted sediment,LOP and MLOP were higher in the heavily polluted sediment,which indicated that heavily polluted sediment was more hazardous than moderately polluted sediment in lake eutrophication.

关键词： bioavailability chemical extracted phosphorus lake sediment middle and lower reaches of the Yangtze River area organic phosphorus fractions

Optimization for epitaxial fabrication of infinite-layer nickelate superconductors

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Frontiers of physics 2024年第3期19卷 61-69页

作者： Minghui Xu Yan Zhao xiang Ding Huaqian Leng Shu Zhang Jie Gong Haiyan Xiao Xiaotao Zu Huiqian Luo Ke-Jin Zhou Bing Huang liang Qiao School of Physics University of Electronic Science and Technology of ChinaChengdu 610054China Beijing Computational Science Research Center Beijing 100193China Diamond Light Source Harwell CampusDidcot OX110DEUnited Kingdom Beijing National laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China Songshan lake Materials laboratory Dongguan 523808China

The discovery of nickelates superconductor creates exciting opportunities to unconventional superconductivity. However, its synthesis is challenging and only a few groups worldwide can obtain samples with zero-resistance. This problem becomes the major barrier for this field. From plume dynamics perspective, we found the synthesis of superconducting nickelates is a complex process and the challenge is twofold, i.e., how to stabilize an ideal infinite-layer structure Nd_(0.8)Sr_(0.2.NiO_(2., and then how to make Nd_(0.8)Sr_(0.2.NiO_(2. superconducting? The competition between perovskite Nd_(0.8)Sr_(0.2.NiO_(3) and Ruddlesden−Popper defect phase is crucial for obtaining infinite-layer structure. Due to inequivalent angular distributions of condensate during laser ablation, the laser energy density is critical to obtain phase-pure Nd_(0.8)Sr_(0.2.NiO_(3). However, for obtaining superconductivity, both laser energy density and substrate temperature are very important. We also demonstrate the superconducting Nd_(0.8)Sr_(0.2.NiO_(2. epitaxial film is very stable in ambient conditions up to 512.days. Our results provide important insights for fabrication of superconducting infinite-layer nickelates towards future device applications.

关键词： nickelate superconductivity infinite-layer plasma condensate plume dynamics

Degradation of organic matterin the sediments of Hongfeng Reservoir

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Science Bulletin 2005年第20期 123-126页

作者： WEI Zhongqing1,2. LIU Congqiang1, liang Xiaobing1, WANG Fushun1 & WANG Shaofeng1, 2.1. State Key laboratory of {2.al Geochemistry, institute of Geochemistry, chinese academy of sciences, Guiyang 550002. china 2. Graduate School of the chinese academy of sciences, Beijing 100039, china

In this work, the distribution of organic carbon, DNA and lipids in the sediments of Hongfeng Reservoir were described in addition to SO42. profile in pore water. The con- tents of organic carbon in the sediments range from 2..3 to 76.8 mg·g?1, with the peak value appearing at the depth of 8 cm bellow the sediments water interface (SWI), and tend to decrease gradually with sedimentation depth. The concentra- tions of SO42. decreased from 40.50 mg·L?1 to 12.00 mg·L?1 at SWI in top 4 cm sediment, and was kept at 12.0 mg·L?1 bel- low that depth. Newly produced organic carbon can be con- served as long as 14 years in the sediments. The contents of DNA were relatively high in top 9 cm surface sediments, as revealed by agarose gel images, close to those of organic car- bon and sulphate reduction index (SRI). This study shows that bacteria played an important role in organic matter degradation; SO42. is the primary electron acceptor under anaerobic condition in this reservoir; DNA in the lake sedi- ments can provide important information for the study of cycling of nutrient elements in the lake.

关键词： lake sediment DNA organic carbon electrophoresis sulfate.

Temporal and dimensional distribution of sulfate-reducing bacteria (SRB) groups and quantity in the sediments of lake Erhai

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Acta Geochimica 2006年第S1期 65-66页

作者： Mingyi WANG, Xiaobing liang, Yaping ZHENG, Youzhi ZHAO, Zhongqing WEI State Key laboratory of {2.al Geochemistry, institute of Geochemistry, chinese academy of sciences, Guiyang 550002. china

High-frequency lacustrine sequence stratigraphy of clastic lakes: lessons from ancient successions

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Journal of Palaeogeography 2024年第4期13卷 621-645页

作者： Carlos Zavala Hua-Qing Liu xiang-Bo Li Valentin Trobbiani Yang Li Mariano Arcuri Agustin Zorzano Departamento de Geología Universidad Nacional del Sur (UNS) GCS Consulting Services.Bahía Blanca Research institute of Petroleum Exploration&Development-Northwest Consejo Nacional de Investigaciones Científicas y T ecnicas (CONICET) Shandong University of Science and Technology

Sequence stratigraphic concepts and methods provide novel tools for performing stratigraphic analysis, allowing us to improve our understanding of depositional models and basin evolution. Main controls and depositional elements(e.g., surfaces, systems tracts, parasequences, etc.) recognized in conventional sequence stratigraphy are designed for marine-related systems. In contrast, the sequence stratigraphy of lacustrine successions is much more complex and poorly understood, because it is not driven by sea-level changes, but by a complex interaction between tectonics and high-frequency climatic cycles. The comprehensive analysis of the water balance of lacustrine systems allows the recognition of three types of lake conditions: Underfilled, balanced-fill and overfilled lakes. Understanding the lake conditions in ancient successions is fundamental for unraveling lacustrine sequence stratigraphy, since these conditions effectively control water salinity, internal stacking pattern and the characteristics of systems tracts. Underfilled lakes are hydrologically closed lakes, and consequently, the lake-level can highly fluctuate, driven by high-frequency wet-dry climatic cycles. During wet periods, rivers supply water and sediments, resulting in fining-and thinning-upward elementary depositional sequences(EDS's) accumulated during the transgressive systems tract(TST). In contrast, dry periods are characterized by a relative lake-level fall with the subaerial exposure of lake margin areas during the regressive systems tract(RST). lake water salinity can fluctuate from brackish to hypersaline. Balanced-fill lakes are partially closed lakes, and consequently, they have characteristics of both underfilled and overfilled lakes. During the TST, the lake is in underfilled condition, and consequently, the introduction of water and sediment will accumulate a fining-upward interval until reaching the spill point during the maximum flooding. The RST is accumulated under an overfille

关键词： Lacustrine sequence stratigraphy Underfilled lakes Balanced-fill lakes Overfilled lakes Forced transgression Forced regression

鄱阳湖流域赣江(南昌段)沉积物磷赋存形态特征及释放风险分析

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湖泊科学 2024年第4期36卷 1121-1130页

作者：向速林楚明航刘丽贞朱林吴永明梁培瑜华东交通大学土木建筑学院南昌330013 江西省科学院微生物研究所南昌330096

本研究采用化学连续提取法,分析赣江南昌段表层沉积物磷赋存形态特征及其生物有效性,并通过等温吸附实验探讨了沉积物磷释放风险。结果显示:赣江南昌段表层沉积物总磷(TP)含量范围为2.5.2.~702.2. mg/kg,均值为52..93 mg/kg,具有较高的... 详细信息

本研究采用化学连续提取法,分析赣江南昌段表层沉积物磷赋存形态特征及其生物有效性,并通过等温吸附实验探讨了沉积物磷释放风险。结果显示:赣江南昌段表层沉积物总磷(TP)含量范围为2.5.2.~702.2. mg/kg,均值为52..93 mg/kg,具有较高的空间异质性。所有采样点位中无机磷(IP)均以闭蓄态磷(Oc-P)为主要赋存形态,各形态无机磷含量特征表现为:Oc-P>铁结合态磷(Fe-P)>碎屑钙磷(De-P)>自生钙磷(ACa-P)>可交换态磷(Ex-P)>铝结合态磷(Al-P);有机磷(OP)以残渣态有机磷(Res-P_(o))为主要赋存形态,按活性划分表现为:非活性有机磷(NOP)>中活性有机磷(MLOP)>活性有机磷(LOP)。生物有效磷(BAP)含量范围为61.59~2.8.2. mg/kg,占TP含量的比例为2..07%。BAP总量及占TP的比例均处于较低水平,沉积物内源磷释放风险较低。BAP中Fe-P平均占比为56.72.,表明沉积物磷潜在释放风险主要来源于Fe-P。TP、Fe-P和De-P之间均存在显著相关关系,表明外源输入可能是赣江沉积物磷的主要来源。采样期间赣江南昌段沉积物磷平衡浓度(EPC 0)高于上覆水溶解性活性磷(SRP)浓度,磷吸附饱和度(DPS)均低于沉积物磷大量流失的临界值2.%,表明此阶段沉积物磷虽作为上覆水的“磷源”,但出现大量释磷的可能性不高。因此,沉积物内源磷释放引起赣江水体富营养化的风险不高,这意味着赣江水体应更多关注外源输入问题。本研究结果为赣江南昌段水环境的科学管理提供了数据支撑和科学依据。

关键词：鄱阳湖流域赣江沉积物磷形态生物有效磷释放风险

浅水湖泊沉积物碳储存与释放及其影响因素研究进展

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水生生物学报 2024年第5期48卷 878-888页

作者：许伟翔白国梁李贝宁吴振斌张义中国地质大学武汉430074 中国科学院水生生物研究所淡水生态和生物技术国家重点实验室武汉430072

碳循环在参与全球物质能量交换流动与影响气候变化中扮演着关键的作用。淡水生态系统碳循环过程是全球碳循环的重要组成部分,因此研究沉积物储存与释放过程能提高人类对淡水生态系统碳循环过程的认识,同时研究沉积物碳储存与释放的影响... 详细信息

碳循环在参与全球物质能量交换流动与影响气候变化中扮演着关键的作用。淡水生态系统碳循环过程是全球碳循环的重要组成部分,因此研究沉积物储存与释放过程能提高人类对淡水生态系统碳循环过程的认识,同时研究沉积物碳储存与释放的影响因素对延缓和治理全球气候变暖措施的制定提供基础理论依据。文章首先综述了淡水生态系统中沉积物碳储存与释放的途径,其次在全球气候变暖的背景下,从气候、水文条件(水位、水质、温度)、生物因素(浮游植物、微生物、水生动物和沉水植物)等方面讨论了影响碳储存和释放的因素,这些因素之间不仅会相互影响与联系,且都会直接或间接对沉积物碳的储存和释放产生影响,沉积物碳的储存和释放的变化是多种因素综合作用的结果。最后对如何应对富营养化淡水生态系统实施固碳增汇进行展望。

关键词：沉积物碳储存碳释放影响因素水文条件沉水植物富营养化

徐家围子断陷沙河子组烃源岩形成古环境及主控因素

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沉积学报 2024年第5期42卷 1753-1764页

作者：孙立东杨亮李笑梅周翔胡博蔡壮杜影中国石油大庆油田勘探开发研究院黑龙江大庆163712

【目的】明确沙河子组优质烃源岩形成的主控因素,为松辽盆地深层天然气勘探方向优选提供地质依据。【方法】综合利用岩心、有机地球化学和元素地球化学等多种资料,系统研究沙河子组沉积环境和水体环境,明确了断裂活动、沉积相和古沉积... 详细信息

【目的】明确沙河子组优质烃源岩形成的主控因素,为松辽盆地深层天然气勘探方向优选提供地质依据。【方法】综合利用岩心、有机地球化学和元素地球化学等多种资料,系统研究沙河子组沉积环境和水体环境,明确了断裂活动、沉积相和古沉积环境对烃源岩有机质丰度、类型的控制作用。【结果】沙河子组发育暗色泥岩和煤岩两种类型烃源岩,沙Ⅰ段沉积期断裂活动强,水体相对局限、深度大,形成的“深水窄盆”盐度高、还原性好,以半深湖相泥岩为主,沙Ⅱ段时断裂活动弱,湖盆面积达到最大,形成的“浅水宽盆”盐度低、还原性变差,烃源岩以滨浅湖相煤岩为主。【结论】断裂活动在下降盘为泥岩堆积提供可容纳空间,控制了泥岩厚度;沉积环境影响有机质输入,决定了泥岩有机质类型和煤岩分布;由古盐度、古水深和氧化还原组成的古沉积环境影响有机质的富集和保存,是导致现今烃源岩质量差异的主要原因。

关键词：微量元素古环境烃源岩控制因素沙河子组