Phytoplankton Productivity and Photophysiology in the Surf Zone of Sandy Beaches in North Carolina, USA

Measurements of primary production in surf-zone habitats are relatively rare and often utilize simulation approaches, owing to the physical challenges of working in surf. The study reported here examined primary production in situ at two open ocean sandy beaches in southeastern North Carolina during relatively calm summer conditions. In situ bottle incubations using ¹⁴C uptake methods were complemented by simultaneous measures of phytoplankton photo-physiology assessed by Fast Repetition Rate Fluorometry (FRRF) in flow-through mode at the two sites across a spring-neap tidal cycle in July, 2010. The surf-zone phytoplankton was dominated by small centric and pennate diatoms as well as cyanobacteria and chlorophytes with biomass concentrations of 3.63?C9.23?mg chl a m^?3. Primary productivity was relatively high, ranging from 31.5?C88.0?mg?C?m^?3?h^?1 by ¹⁴C. Biomass-specific productivity averaged ??9.4?mg C (mg chl a)^?1?h^?1 by ¹⁴C, indicating healthy phytoplankton populations. Measurements of the functional absorption cross section of photosystem II, ??_PSII, via FRRF were 327?C380, comparable to values reported by other investigators of open ocean phytoplankton. Averaged values of the maximum effective quantum yield, F _v/F _m, corresponded to proportions of photochemically competent PSII reaction centers of 62.6?% to 72?%, indicating that the phytoplankton were nutrient-replete. These data suggest that the surf zone, although a spatially confined habitat, is a productive one that plays a significant role in coastal ocean ecology. Further investigation is needed to better understand primary productivity of phytoplankton in the surf zone and the effect of the dynamic environment on their physiological responses.     

Spring and Summer Larval Fish Assemblages in the Surf Zone and Nearshore off Northern New Jersey,USA

Larval fish use of surf zone and nearshore habitats at northern latitudes has received little attention. Consequently, potential impacts of beach nourishment and other forms of disturbance are not well understood. This study, on a northwestern Atlantic coastline spanning May through July over 4 years, demonstrates that recently hatched larvae are common in both surf zone and nearshore habitats. Taxonomic compositions of surf zone and nearshore assemblages were similar to each other and those from an adjacent estuary. An influence of upwelling events was apparent in coincident changes in abundance and/or size of several species in the surf zone. Other changes over the late spring–summer transition, including buoyancy-driven flows from the Hudson River plume, demonstrate the dynamic nature of larval fish assemblages in the New York Bight area.     

Phytoplankton Growth Balanced by Clam and Zooplankton Grazing and Net Transport into the Low-Salinity Zone of the San Francisco Estuary

We estimated the influence of planktonic and benthic grazing on phytoplankton in the strongly tidal, river-dominated northern San Francisco Estuary using data from an intensive study of the low salinity foodweb in 2006–2008 supplemented with long-term monitoring data. A drop in chlorophyll concentration in 1987 had previously been linked to grazing by the introduced clam Potamocorbula amurensis, but numerous changes in the estuary may be linked to the continued low chlorophyll. We asked whether phytoplankton continued to be suppressed by grazing and what proportion of the grazing was by benthic bivalves. A mass balance of phytoplankton biomass included estimates of primary production and grazing by microzooplankton, mesozooplankton, and clams. Grazing persistently exceeded net phytoplankton growth especially for larger cells, and grazing by microzooplankton often exceeded that by clams. A subsidy of phytoplankton from other regions roughly balanced the excess of grazing over growth. Thus, the influence of bivalve grazing on phytoplankton biomass can be understood only in the context of limits on phytoplankton growth, total grazing, and transport.     

浮游植物叶绿素a含量不同方法测定比较——以白洋淀区域水体为例

实验使用国际上较通用的热乙醇萃取分光光度法、国内常用的丙酮萃取分光光度法、BBE藻类分类测定仪及YSI多参数测定仪测定浮游植物的叶绿素a,并将这4种方法的测定结果进行了比较。结果表明丙酮法的测定结果相对较高;BBE藻类分类仪检测叶绿素a较接近于乙醇法的叶绿素a的测定结果,线性关系和回归系数也最好,丙酮法测定的结果次之,YSI现场多参数检测结果与乙醇法叶绿素a的测定结果差别较大。实验得出,BBE藻类分类仪检测结果可进行部分采用,而YSI现场多参数检测结果可作为实验的参考值,而且离心的步骤省略对实验结果影响较大。     

海洋浮游植物对磷的响应研究进展

磷是海洋浮游植物赖以生存的一种必需营养元素.海洋浮游植物对磷的响应,与初级生产力、碳循环以及固氮作用密切相关.总结了浮游植物可利用的磷源:优先吸收溶解无机磷;在寡磷海域,可通过相关酶类协助利用溶解有机磷来抵御无机磷的缺乏.对比了不同种类浮游植物对不同形态磷源利用方式的差异并从浮游植物生理学角度阐述了存在差异的根本原因.探讨了浮游植物对低磷环境的响应机制.近期的研究发现浮游植物细胞表面可以吸附磷,该发现有利于更加准确地衡量浮游植物承受的营养盐限制问题,进一步完善对海洋磷储库及其生物地球化学循环的认识.最后提出了今后需进一步研究的关键科学问题:浮游植物细胞表面吸附磷的机制;对不同结构有机磷化物的利用机理;浮游植物对磷的海洋生物地球化学循环的响应及反馈作用.     

敦密断裂带盆地群油页岩特征及成矿差异分析

古近纪敦密断裂带上分布一系列的含油页岩盆地群。根据盆地间构造-沉积充填、岩石组合和油页岩赋存特征,初步确认盆地群中油页岩沉积于湖盆鼎盛阶段,均形成于古近系始新统路特阶。盆地群间油页岩矿床特征存在明显的差别,由西南向东北,油页岩厚度逐渐变小,其沉积环境由深湖到半深湖,再到湖沼,而有机质来源则由湖泊生物为主,到湖泊生物和陆源有机质双向来源,过渡为以陆源高等植物为主。结合含油页岩层系形成于同一时期和相似的古气候背景下,盆地沉降和沉积充填作用是影响油页岩矿床差异的关键因素。长期处于欠补偿环境,可容纳空间大的湖盆利于巨厚油页岩的形成,随着可容纳空间的减少、陆源碎屑供给的增多,油页岩厚度减薄,分布也变得相对局限。深湖和湖沼成因油页岩品质较好,半深湖油页岩品质较差。     

断裂带土中氡浓度影响因素分析及特征曲线应用

土壤中的氡气（Rn）是研究断裂的一个有效手段,通过氡浓度变化曲线可以大致确定断裂带的位置、范围和产状等。一般而言,断裂带上方呈现Rn峰值异常,远离断裂带逐渐衰减至正常水平。土壤中氡浓度变化取决于断裂的规模、倾角、岩性、破碎带宽度、充填物透气性、覆盖层、地下水、稀释效应和放射性平衡等因素。     

Spatial-temporal Variations of H2 Concentration in Soil Gas in the Seismic Fault Zone Produced by the Wenchuan MS 8.0 Earthquake

Degassing of Hydrogen (H₂) from fault may be a good indicator of fault activity. The concentration of H₂ in soil gas in the seismic surface rupture zone produced by the Wenchuan M_S 8.0 earthquake was investigated in twenty three measuring regions in order to explore the relationship between the spatio-temporal variations of H₂ concentration in soil gas along the seismic rupture zone and the vertical displacements and aftershocks activities. The results indicated: ① the sources of H₂ were directly related to from the release of natural gas reservoirs; ②the average concentration of H₂ in soil gas spatially decreased from Yingxiu to Nanba; ③the magnitudes of the H₂ concentration anomalies declined significantly with time. It is very significant to study the variation tendency of atmospheric environment with further research of degassing of H₂ from faults.     

季节冻土区地下水观测成果在流域产汇流理论研究中的应用述评

将山坡水文学产流机制——超渗地面径流、饱和地面径流、壤中径流和地下径流等成分的产流机制,概括为界面(不透水层)产流机制。介绍季节冻土区近地表地下水若干创新的观测成果,综述其在季节冻土区流域产汇流理论研究领域中的应用,建议水利、农业、气象、林业、地质等部门在季节冻土区近地表地下水观测方面通力合作。可以预期,季节冻土区近地表地下水观测成果在产汇流理论研究以及流域水文模型研制中得到进一步的应用。     

山东胶西北地区金矿密集区资源潜力预测

以陈毓川院士提出的矿床成矿系列理论为指导,利用矿床模型综合地质信息预测方法分析提取了山东胶西北地区5个典型矿床预测要素,结合典型矿床及其他矿床成矿特征,提取区域预测要素,建立区域预测模型。中生代玲珑二长花岗岩和郭家岭花岗闪长岩,大的俯冲背景下的伸展拉张作用形成的构造控矿成矿环境,胶东构造岩浆岩亚带、胶北侵入岩段、陆缘岩浆弧构造背景,北北东、北东向韧、脆性断裂带、构造裂隙控矿是金成矿的4个必要要素。胶东岩群表壳岩系和古元古代俯冲增生杂岩地层,中生代燕山晚期成矿,自然金、黄铁矿矿物组合,钾化、黄铁绢英岩围岩蚀变是金成矿的重要要素;区域布格重力异常、航磁异常、水系沉积物异常、自然重砂异常特征是金矿床存在的重要指示特征。依据综合预测要素特征,预测模型定位预测区;按控矿构造系统展布、金等化探和重砂异常分布特征、布格重力异常梯度带、有利磁场场区范围等圈定预测区平面边界;以具体控矿构造范围、规模、现有矿体控制深度和矿体深部可能的延伸特征圈定预测区深部边界。全区圈定预测区63个,其中,A级17个,B级11个,C级35个。分区域、地段、深度、级别（类别）定量估算2 km以浅资源量,全区预测金金属资源量 3 250 t。     

Phytoplankton Size and Taxonomic Composition in a Temperate Estuary Influenced by Monsoon

Temporal and spatial variations in phytoplankton in Asan Bay, a temperate estuary under the influence of monsoon, were investigated over an annual cycle (2004). Phytoplankton blooms started in February (>20 μg chl l⁻¹) and continued until April (>13 μg chl l⁻¹) during the dry season, especially in upstream regions. The percentage contribution of large phytoplankton (micro-sized) was high (78–95%) during the blooms, and diatoms such as Skeletonema costatum and Thalassiosira spp. were dominant. The precipitation and freshwater discharge from embankments peaked and supplied nutrients into the bay during the monsoon event, especially in July. Species that favor freshwater, such as Oscillatoria spp. (cyanobacteria), dominated during the monsoon period. The phytoplankton biomass was minimal in this season despite nutrient concentrations that were relatively sufficient (enriched), and this pattern differed from that in tropical estuaries affected by monsoon and in temperate estuaries where phytoplankton respond to nutrient inputs during wet seasons. The flushing time estimated from the salinity was shorter than the doubling time in Asan Bay, which suggests that exports of phytoplankton maximized by high discharge directly from embankments differentiate this bay from other estuaries in temperate and tropical regions. This implies that the change in physical properties, especially in the freshwater discharge rates, has mainly been a regulator of phytoplankton dynamics since the construction of embankments in Asan Bay.     

黄铁矿净化水中低浓度磷

以产自安徽铜陵新桥矿的黄铁矿为典型样品,研究黄铁矿对磷的吸附作用。静态实验考察黄铁矿粒度、固液比、pH值、离子强度、温度、吸附时间等因素对黄铁矿去除磷效果的影响,XPS和FE-SEM研究吸附磷后黄铁矿颗粒表面形貌和成分特征。结果表明：黄铁矿粒径越小（50～180目）,去除磷效率越高（9.3%～90.7%）;提高固液比（0.2～2 g/L）,磷的去除率增加（6.5%～97.1%）;在pH值3～9.65范围内黄铁矿对磷都有很好的去除效率（95%以上）;NO3-对磷的去除效果表现为微弱的促进作用,Cl-有微弱的抑制作用,溶液中SO42-、HCO3-对黄铁矿吸附磷表现出较强的抑制作用。温度对黄铁矿吸附效率基本没有影响。黄铁矿对磷吸附动态实验表明除磷效率在16 h后接近最大值。除磷作用机理是黄铁矿表面缓慢氧化产生的三价铁对磷的化学吸附。成果表明黄铁矿用于净化污水中低浓度磷具有很大的潜力。     

Inorganic and Organic Nitrogen Uptake by Phytoplankton and Bacteria in Hong Kong Waters

Measurements of uptake rates of inorganic (NO₃⁻ and NH₄⁺) and organic (urea, glycine, and glutamic acid) N, and indirect estimates of total N uptake by bacteria, were made in four contrasting environments in sub-tropical Hong Kong waters in summer of 2008. In addition, the effects of several days of rain on N uptake rates were studied in eastern waters. Although ambient NO₃⁻ was the dominant form of N in Hong Kong waters, the dominant N form taken up by phytoplankton was usually NH₄⁺ and organic N, including urea and amino acids, rather than NO₃⁻. Hence, because of the low NO₃⁻ uptake, there was a long turnover time for NO₃⁻ (100 days), and most of the NO₃⁻ was apparently transported offshore into deeper shelf waters. In eastern waters where NH₄⁺ was undetectable, NO₃⁻ uptake rates were positively correlated with phytoplankton cell size. In contrast, potential rates of glutamic acid uptake were negatively correlated with phytoplankton size. N uptake rates in the smaller size fraction (0.7–2.8 μm) were less affected by the rain event, and smaller phytoplankton appeared to outcompete larger cells after several days of rain. The surface (PN)-specific N uptake rates in the >8-μm fraction decreased from 0.02 to 0.0001 h⁻¹, while the smaller fraction only exhibited a one- to threefold decrease after the rainfall. In contrast, bacterial production and N uptake were not affected by the rain event, and bacteria N uptake accounted for 10–60% of the total N uptake by phytoplankton.     

塔河油田TK665CH井卡拉沙依组锻铣侧钻水平井技术

近年来,在塔河油田老区直井基础上进行177.8 mm套管开窗（149.2 mm井眼）侧钻是主要开发方向之一。石炭系卡拉沙依组锻铣开窗存在循环压耗大,铁屑上返排量窗口窄,铁屑容易在锻铣套管上窗口堆积,易发生铁屑憋泵、缠刀、退刀困难,侧钻时地层压实性好,机械钻速低,井壁掉块卡钻,穿越两套压力体系井漏,摩阻扭矩大等复杂情况。在TK665CH井石炭系卡拉沙依组177.8 mm套管锻铣开窗侧钻施工中,通过钻头、钻进参数、导向马达、钻具组合的优选,轨迹的监控以及针对性的泥浆技术,侧钻获得成功,为塔河油田老井改造及定向侧钻积累了成功的经验。     

Ophiolite emplacement by strike-slip tectonics between the Pontide Zone and the Sakarya Zone in northwestern Anatolia, Turkey

Northwestern Anatolia contains three main tectonic units: (a) the Pontide Zone in the north which consists mainly of the Gstanbul-Zonguldak Unit in the west and the BallLda<-Küre Unit in the east; (b) the Sakarya Zone (or Continent) in the south, which is juxtaposed against the Pontide Zone due to the closure of Paleo-Tethys prior to Late Jurassic time; and (c) the Armutlu-OvacLk Zone which appears to represent a tectonic mixture of both zones. These three major tectonic zones are presently bounded by the two branches of the North Anatolian Transform Fault. The two tectonic contacts follow older tectonic lineaments (the Western Pontide Fault) which formed during the development of the Armutlu-OvacLk Zone. Since the earliest Cretaceous, an overall extensional regime dominated the region. A transpressional tectonic regime of Coniacian/Santonian to Campanian age caused the welding of the Gstanbul-Zonguldak Unit to the Sakarya Zone by an oblique collision. In the Late Campanian, a transtensional tectonic regime developed, forming a new basin within the amalgamated tectonic mosaic. The different tectonic regimes in the region were caused by activity of the Western Pontide Fault. Most of the ophiolites within the Armutlu-OvacLk Zone belong to the Paleo-Tethyan and/or pre-Ordovician ophiolitic core of the Gstanbul-Zonguldak Unit. The Late Cretaceous ophiolites in the eastern parts of the Armutlu-OvacLk Zone were transported from Neo-Tethyan ophiolites farther east by left-lateral strike-slip faults along the Western Pontide Fault. There is insufficient evidence to indicate the presence of an ocean (Intra-Pontide Ocean) between the Gstanbul-Zonguldak Unit and the Sakarya Zone during Late Cretaceous time.     

Phytoplankton assemblage in the Plio-Pleistocene record of Lake Baikal as indicated by sedimentary steryl chlorin esters

Past changes in phytoplankton assemblages in Lake Baikal over the last 4.5 Ma, both in population and composition, are inferred from the downcore profiles of the relatively stable chlorophyll derivatives steryl esters of pyropheophorbides a and b (steryl chlorine esters; SCEs) in the 0–200 m section of the BDP-98 drill core, supplemented by the data on biogenic silica (BSi) and total organic carbon (TOC) contents. SCEs-a and -b dominate among sedimentary chlorophyll derivatives in the BDP-98 sediments except for the upper few meters, indicating their high stability during diagenetic alteration of sediments. The depth (age) profiles of SCEs-a are consistent with BSi and TOC profiles and are interpreted as reflecting primary productivity of the lake in the past. Baikal proxies reveal close correlation with marine oxygen isotope records (MIS stratigraphy). These observations confirm that climate change in the northern hemisphere has been a primary factor controlling the total phytoplankton productivity in Lake Baikal during the last several million years.Among SCEs-a, C₃₀ (dinostanol)-SCE-a, a marker of dinoflagellates was identified by GC–MS analysis. SCE-b, a marker of green algae, was identified by its UV–vis spectrum. The ratio of C₃₀-SCE-a to total SCEs-a (TSCEs-a) was higher during 4.5–4.2 and 1.7–1.3 Ma, suggesting that dinoflagellates proliferated preferentially in those periods. The early Pleistocene maximum of this ratio corresponds to the broad minimum of diatom abundance previously suggested to have recorded a prolonged regional cooling. An abrupt increase in the SCE-b/TSCEs-a ratio was observed at 2.5–2.6 Ma, indicating that green algae containing chlorophyll b have proliferated in Lake Baikal during this period. This interval has also been suggested to contain evidence for a significant regional cooling based on minima of diatom abundance and BSi in sediments. The depth profile of C₂₇Δ⁵ (cholesterol)-SCE-a relative to TSCEs-a showed a trend similar to that of BSi, suggesting that C₂₇Δ⁵-SCE-a/TSCEs-a ratio is a potential marker of diatoms in Lake Baikal.Certain mismatches between the Lake Baikal profiles of biological indicators and the marine oxygen isotope records, as well as the slight temporal offsets between different Lake Baikal biological marker signals suggest that the regional component of climatic and/or lacustrine environmental changes also have played a role in determining the composition of the Lake Baikal Plio-Pleistocene phytoplankton assemblage.     

Heterogeneous deformation recorded by magnetic fabrics in the Pyrenean Axial Zone

Magnetic fabrics studies (AMS) are a useful tool in order to describe the distribution of deformation in orogenic areas where conventional techniques are difficult to apply, especially due to the lack of proper strain markers. In the present study, AMS and structural analysis are used to define the distribution of deformation in the Central Axial and Nogueres Zones, an area of strong structural changes (i) in the geometry of the antiformal stack defining the Pyrenean Axial Zone and (ii) the distribution of Alpine cleavage. The studied rocks are Lower-Middle Triassic red beds that crop out in three different stacked thrust units (Bielsa, Nogueres and Orri). Primary sedimentary fabrics are preserved in the uppermost thrust units (Nogueres Zone), but a high percentage of the sampling sites shows an overprint of Alpine compression on magnetic fabrics, with the magnetic lineation mostly parallel to the tectonic grain defined by compressional structures and the magnetic foliation showing different orientations between the poles to cleavage and bedding. The development of compressional fabrics strongly depends on the structural position of the sites, and two deformation gradients can be inferred: the southern margin of the Axial Zone (Orri and Bielsa units) shows strong internal deformation, increasing towards the North; farther north (in the restored cross-section), deformation is in general terms lower, but increases towards the basal thrust of the Nogueres Zone. The heterogeneous distribution of Alpine internal deformation indicates a preferred development of cleavage in the Variscan basement and overlying units of the southern margin of the Axial Zone (mainly in the Orri unit), that could be partly controlled by the tectonic load resulting from the stacking of thrust sheets.     

Total Sulfur Concentration in Geological Reference Materials by Elemental Infrared Analyser

Total sulfur is an analyte for which there are few determinations published, despite the fact that it is a very important element (e.g., a major element in most ores, an important gas constituent in global warming, an active participant in acid drainage). Most geological reference materials have very poor quality sulfur results, that is with relative standard deviations (RSD) in the range of 30–50%, even for concentrations over 100 μg g⁻¹ S, which compromises their use as calibrators. In order to provide modern results with low RSD, sulfur was determined in twenty-nine geological reference materials with a state-of-the-art elemental S/C analyser using metal chips (certified reference materials with a traceability link) and analytical grade sulfur for high concentration samples. Analytical parameters (sample mass, crucible degassing, calibration strategy, etc.) were optimised by testing. Our results agreed with reference material values provided by issuing bodies. Results for CCRMP SY-2 (129 ± 13 μg g⁻¹ S), which has been proposed as a sulfur reference material, were in agreement with the proposed modern value of 122 ± 3.7 μg g⁻¹ S.     

水平定向钻进管道敷设地层响应实验分析

在应用水平定向钻进非开挖技术进行近地表管道敷设时,由于上覆地层厚度(C)、钻孔直径(D)和钻井液压力(p)三者无法准确设计,往往会导致地表的变形,进而形成裂缝通道致使地表发生钻井液的溢流.分析了非黏聚力地层的溢流通道形式,同时推导了极限钻井液压力的计算公式.结合室内外实验及应用情况,得出了实测钻井液压力和计算钻井液压力同C/D值的变化规律,即C/D越大,极限钻井液的压力值也就越高.在同一地层中,一般钻井液压力的峰值出现在水平孔段的中间位置.根据C/D值,在保证钻井液不发生溢流的情况下,得出了不同水平孔径范围所对应的上覆地层最小厚度.