2006年秋季长江口及邻近海域微微型浮游生物的分布特征及环境影响因素   总被引：3，自引：0，他引：3  

乐凤凤  刘诚刚  郝锵  史君贤  翟红昌 《海洋学研究》2011,(3):108-117

2006年10月在长江口及邻近海域采用流式细胞技术测定了微微型浮游生物:聚球藻Synechococcus、微微型光合真核生物(picoeukaryotes)和异养浮游细菌(heterotrophic bacteria)的丰度和碳生物量,研究了其生态分布特点,并分析了其与环境因子之间的关系.结果表明,聚球藻、微微型光合真...  相似文献   

南美洲鳗鲡(Anguilla rostrata)的耗氧率(ROC)、窒息点(AP)和适温范围(RT)及对非离子氨(NIA)、NO2-的LC50和SC的研究     

杨小东  江兴龙  乐普敏  龚铭杰 《海洋与湖沼》2019,50(2):455-464

为研究南美洲鳗鲡(Anguillarostrata)的耗氧率及其对水温、低溶氧、非离子氨和亚硝酸盐耐受性,本研究采用自制的鱼类呼吸装置测定其耗氧率和窒息点,以黑仔鳗为试验材料,探索其对水温、非离子氨、亚硝酸盐耐受性。结果表明,南美洲鳗鲡耗氧率存在昼夜变化,其昼间耗氧率为(86.46±37.77)mg/(kgh),夜间耗氧率为(123.58±22.56)mg/(kgh),二者存在显著性差异(P0.05);在15—30°C范围内,耗氧率随温度升高逐渐增大,耗氧率和水温的回归方程y=–0.1316x2+9.4507x–13.712(R2=0.9993);南美洲鳗鲡的耗氧率随体质量增大而降低,耗氧量随体质量增加而增大,耗氧量和体重的回归方程为y=0.2321x0.8334(R2=0.9979);在水温25°C时其窒息点随鱼体质量的增大而降低,均重10g、40g和160g的鳗鲡窒息点溶解氧浓度分别为(0.98±0.25)、(0.46±0.06)和(0.32±0.02)mg/L;13—29°C为南美洲鳗鲡的适温范围,25—29°C为其生长适宜水温,在一定范围内的短时低水温或高水温环境对其损伤是可逆的;水中非离子氨对南美洲鳗鲡的LC50和SC分别为12.22mg/L和1.22mg/L,亚硝酸盐氮对南美洲鳗鲡的LC50和SC分别为61.68mg/L和6.17mg/L。  相似文献   

三门湾沉积记录中长链烯酮不饱和指数-海表温度和浮游动物群落对厄尔尼诺/拉尼娜的响应   总被引：2，自引：1，他引：1  

张海生  宁修仁  乐凤凤  胡锡钢  刘镇盛  卢冰 《海洋学报》2010,32(3):40-50

应用沉积地层记录中长链烯酮不饱和指数(U3K7)估算1916—2003年三门湾表层海水温度(SST)与变化。SST波动范围为15.97~18.00℃,年平均为17.03℃。该值比当年实测海水全年平均温度低3.52℃,同时应用长链烯醇不饱和指数与SST的关系重建历史上的厄尔尼诺现象。研究显示三门湾的厄尔尼诺气候事件在大尺度上与东太平洋一样均受制于气候影响,在变化尺度上又受到地理位置和地方性气候(季风)的影响,厄尔尼诺事件在形式和年代上相互对应,但是其涛动幅度不如东太平洋的强烈。通过比较厄尔尼诺期间(2003/2002年)和非厄尔尼诺期间(2006/2005年)的浮游动物群落结构变动信号、生物量、密度以及物种多样性等,在厄尔尼诺时期浮游动物种类数、生物量和丰度呈现偏高的趋势,三门湾的暖水性浮游动物类群、数量变化与台湾暖流活动过程中携带的浮游性动物有密切的联系。  相似文献   

Three types of 2-degree field compensating atmospheric dispersion correctors for prime focus     

Xu Wen-li  Wang Ya-nan 《Chinese Astronomy and Astrophysics》1993,17(4):464-472

Three types of prime focus correctors for Chinese 2.16m telescope are introduced in this paper. Each corrector has a 2 degree field and can be used to compensate the atmospheric dispersion of 6″. All the three correctors have excellent image quality and the angles between the principal rays and the optical axes are quite small. There is no special technological difficulty in their fabrication. These designs can not only be used in the 2.16m telescope but also be applied to other large telescopes.  相似文献   

孤岛油田南区馆1+2砂层组细分对比标志特征   总被引：1，自引：0，他引：1  

乐大发  陈清华  张福利 《地球科学与环境学报》2011,33(1):84-88

基于沉积学和储层地质学理论,以孤岛油田南区馆1+2砂层组高弯曲流河沉积为例,充分利用密井网条件下的测井资料,研究储层细分对比中的标志类型、特征、分布及其应用。首先,介绍了馆1+2砂层组的测井响应、地震反射等宏观特征;接着,利用感应电导率曲线、自然电位曲线的响应特征寻找细分对比标志;然后,将选取的标志联合使用得到孤岛油田南区馆1+2砂层组的顶面构造图。结果表明:研究区缺少全区性标志,但存在局部性标志;局部性标志有泥岩类、砂岩类、"钙质尖"类、砂泥组合类等4类;泥岩类标志表现出高感应电导率特点,砂岩类标志表现为低电阻率,自然电位曲线呈"箱形"或小型的"钟形","钙质尖"类标志表现为高电阻、高微电阻、低声波时差,低自然电位值的尖锋,砂泥组合类标志表现为感应曲线特征的可对比性强;泥岩类和砂岩类标志分布面积较大,呈局部连片状;"钙质尖"类和砂泥组合类标志分布面积较小,呈条带状;上述4类标志在平面上的叠合分布完全覆盖研究区。总之,充分利用好局部性标志,同样能够很好地进行类似地区的储层细分对比。  相似文献   

Integration of remote sensing data into hydrological models for reservoir management     

C. LOUMAGNE  M. NORMAND  M. RIFFARD  A. WEISSE  A. QUESNEY  S. LE HÉGARAT-MASCLE 《水文科学杂志》2013,58(1):89-102

Abstract

The purpose of this paper is to present the methodology set up to derive catchment soil moisture from Earth Observation (EO) data using microwave spaceborne Synthetic Aperture Radar (SAR) images from ERS satellites and to study the improvements brought about by an assimilation of this information into hydrological models. The methodology used to derive EO data is based on the appropriate selection of land cover types for which the radar signal is mainly sensitive to soil moisture variations. Then a hydrological model is chosen, which can take advantage of the new information brought by remote sensing. The assimilation of soil moisture deduced from EO data into hydrological models is based principally on model parameter updating. The main assumption of this method is that the better the model simulates the current hydrological system, the better the following forecast will be. Another methodology used is a sequential one based on Kalman filtering. These methods have been put forward for use in the European AIMWATER project on the Seine catchment upstream of Paris (France) where dams are operated to alleviate floods in the Paris area.  相似文献   

Petrology and Geochemistry of MORB from 25?E to 46?E along the Southwest Indian Ridge: Evidence for Contrasting Styles of Mantle Enrichment     

LE ROEX  ANTON P.; DICK  HENRY J. B.; FISHER  ROBERT L. 《Journal of Petrology》1989,30(4):947-986

The 1984 PROTEA expedition, leg 5, to the central SouthwestIndian Ridge recovered basaltic lavas from fracture zones andridge segments between 25?E and 48?E. In terms of petrographyand major element variations the samples are unremarkable forocean ridge basalts and range from aphyric to highly plagioclasephyric and from primitive (mg-number = 70) to moderately evolved(mg-number = 40) in composition. Multiply saturated (i.e., olivine,plagioclase, and clinopyroxene) basalts are common within thisregion. There is no systematic difference in compositional characteristicsbetween basalts dredged from fracture zone walls and those dredgedfrom ridge segments, and fractional crystallization has playedan important role in controlling the overall range in lava compositionin both tectonic environments. Incompatible element abundance ratios in the basalts are morenotable and distinguish between geochemically depleted (N-type)MORB with high Zr/Nb (1668) and Y/Nb (4?723) ratios and low(La/Sm)^m, ratios (0-?76–1?00), and geochemically enriched(E-type) MORB with low Zr/Nb (3?4–15?8) and Y/Nb (0?5–8?8)and high (La/Sm). ratios (1?07–3?8). N-type MORB appearsto be absent in the immediate vicinity of Marion Island, butoccurs further along the ridge to the northeast and southwest.Geochemically enriched MORB occurs at scattered localities alongthe ridge but is particularly abundant along the section ofthe ridge closest to the Marion hotspot. In detail, two distinct varieties of E-type MORB can be recognized.The one type has incompatible element and isotopic ratios similarto, although slightly less enriched than, those characteristicof the Marion hotspot (Zr/Nb=5?8–8?6; Y/Nb=0?5–0?8;Ba/Nb=5?1–9?0). The second type can be distinguished byhaving high Ba/Nb ratios (9–22), unlike any lavas directlyassociated with the Marion hotspot, but similar to those characteristicof DUPAL ocean island basalts (OIB). A single sample from thisgroup for which there are isotopic data indicates derivationfrom an isotopically anomalous source region. A model is proposed whereby the sub-oceanic mantle below thisportion of the southwest Indian Ocean has experienced at leasttwo distinct enrichment events. The one is associated with theupwelling of the Marion mantle plume (geochemically characterizedby having low Ba/Nb ratios and normal OIB isotopic ratios).The other is associated with upwelling from a DUPAL source (characterizedby having high Ba/Nb ratio and unusual isotopic ratios) whichhas been proposed to exist beneath this portion of the southwestIndian Ocean (Hart, 1984). On the basis of Ba/Nb and Nb/U ratios,recycled oceanic lithosphere is favoured as a source for theMarion hotspot, while recycled oceanic lithosphere plus ancientpelagic sediment appears to be the most likely source for theDUPAL anomaly and the DUPAL E-type MORB in this region.  相似文献   

链烷烃的热力学性质与分子拓扑指数的关系   总被引：1，自引：0，他引：1  

饶火瑜  朱霞萍  乐长高 《华东地质学院学报》2002,25(3):244-249

定义了一种新的连接性指数^1Y=Σk1/m^2 n^2,研究了链烷烃的标准生成焓、标准熵、标准生成吉布斯自由能等三个热力学性质与碳原子个数N，^1Y之间的定量关系，相关系数为优，其计算值与实验值较为接近，对未参与回归的正癸烷的60个异构体的三个热力学性质进行了计算，计算值与实验值较一致。  相似文献   

海洋真菌的化学研究     

乐长高  林永成 《华东地质学院学报》2001,24(1):48-51

综述了从海洋真菌中分离出结构新奇、有特殊生物活性和有潜在实用意义的新化合物。  相似文献   

A Round of Growth: The Verdict on New Zealand's Programme of Regional Development?     

R. B. LE  HERON 《New Zealand geographer》1979,35(2):71-79

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