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1.
南沙群岛海区有机碳沉积作用与古生产力估算 总被引：6，自引：0，他引：6
根据南沙群岛海区５个沉积柱样和大量表层样的分析资料讨论了有机磷的沉积作用。深海有机碳含量一般为０．２％－１．３％。水柱深度对其分布的控制作用不明显。分析结果发现冰期、间冰期，尤其是末次冰期有机碳含量变化明显，４个柱样晚第四纪的质量堆积速率在末次冰期时最大。 相似文献
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元素分析仪快速测定海洋沉积物TOC和TN的条件优化 总被引：4，自引：0，他引：4
报道了在优化样品前处理、燃烧温度、最小加氧量和最佳称样量的基础上,综合构建优化了直接固体进样varioMACRO cube元素分析仪同时测定海洋沉积物样品中总有机碳(TOC)和总氮(TN)的条件,即准确称取20~30 mg沉积物样品用1 mol/L盐酸除去无机碳后,直接进样在燃烧管温度960℃,次级燃烧管温度830℃,还原管温度900℃,氦气压力0.12 MPa,流量600 mL/min,氧气压力0.20 MPa,加氧量22.5 mL仪器条件下,用标准曲线法峰面积获取TOC和TN浓度。结果表明,海洋沉积物中TOC和TN测定的检出限分别为0.0508%和0.0146%,回收率分别为97.7%~100.9%和97.2%~101.1%,对4个实际外海沉积物样测定总有机碳和总氮结果的相对标准偏差(RSD)为0.83%~3.06%和1.33%~3.49%(n=12)。该方法操作简便快速、灵敏度高,具有较好的精密度和准确度,可准确可靠地用于海洋沉积物中总有机碳和总氮含量的测定。 相似文献
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海口港纳潮量及其变化遥感研究 总被引：3，自引：0，他引：3
通过对遥感影像中提取的水域面积，结合潮汐资料建立的纳潮量算式的方法，得到海口港１９９０年纳潮量为２．５７×１０＾７ｍ＾３，１９８４年为２．９４×１０＾７ｍ＾３，１９６５的为２．６２×１０＾ｕ７ 相似文献
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南沙群岛海区有机碳沉积作用与古生产力估算 总被引：1，自引：0，他引：1
根据南沙群岛海区５个沉积柱样和大量表层样的分析资料讨论了有机碳的沉积作用。深海有机碳含量一般为０．２％－１．３％。水柱深度对其分布的控制作用不明显。分析结果发现冰期、间冰期，尤其是本次冰期有机碳含量变化明显，４个柱样晚第四纪的质量堆积速率在末次冰期时最大。有机碳保存的主要控制因素是溶解氧浓度、粘土矿物含量、水柱深度和底栖混合强度，其中溶解氧浓度是最重要因素。底栖有孔虫的相对丰度，如Ｕｖｉｇｅｒｉｎａ和Ｂｕｌｉｍｉ－ｎａ，可用来指示溶解氧和有机碳含量。有机碳含量与海洋生产力关系极为密切，它可用来重建海洋古生产力的长期变化。采用Ｍｌｌｅｒ和Ｓｕｅｓｓ方程以及Ｓａｒｎｔｈｅｉｎ方程的计算结果与目前生产力值结果比较表明，后一种方法因充分考虑了溶解氧浓度和水柱深度而更接近现代值。 相似文献
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本文在σ坐标下建立了一个半诊断计算及预报计算的数值模式，应用于台湾海峡夏季时三维海流计算。计算结果表明，当ｔ＝２．５ｄ时，密度场和速度场得到调整，即得到半诊断解，当ｔ＝４０ｄ以后，解已达到准稳定态；半诊断及预报计算的结果在定性上是与诊断计算结果一致。但它们在定量上有些变化，如表层台湾岛西岸附近的最大水平流速，在ｔ＝０时（诊断）为５９．１ｃｍ／ｓ，ｔ＝２．５ｄ时（半诊断）为６２．１ｃｍ／ｓ，ｔ＝３００ｄ时（预报）为６２．０ｃｍ／ｓ．此外，在半诊断及预报计算中，上升流也主嵰⑸诟＝ń兜龋魉偌忧浚段б灿兴┐蟆 相似文献
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本文对《向阳红九号》调查船做了空气微生物的监测，结果表明：平均全船舱内空气微生物总量、空气真菌含量、空气真菌量占空气微生物总量的百分数分别是３７３０．９ＣＦＵｍ－３，１６８．１ＣＦＵｍ－３和１５．３×１０－２。尚未超过国家对客船规定的卫生标准，但有２１×１０－２的测定结果已超标。两次测定间的差异主要由空气扰动状况所致；层间及舱室间的差异是因人员工作生活习惯等造成的。结果还表明，较好条件的上层乃至全船舱室大有改善环境卫生条件的必要。 相似文献
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主要研究了南沙群岛海域 湖及其礁外沉积物间隙水中的Ｆｅ２＋，Ｍｎ２＋，Ｍｎ／Ｆｅ值及礁外／ 湖值、沉积物—海水界面扩散通量、沉积类型及其氧化还原环境。结果表明，间隙水中Ｆｅ２＋，Ｍｎ２＋浓度 写湖高于礁外，锰高于铁，礁外／渴湖值Ｆｅ２＋为０．２８，Ｍｎ２＋为０．６６，Ｍｎ／Ｆｅ值 湖内为１．４７，礁外为３．５２，界面扩散Ｆｅ２＋，Ｍｎ２＋均是从沉积物向上覆海水扩散，扩散量的Ｍｎ／Ｆｅ值 湖为１．３８，礁外为３．８４，Ｆｅ２＋，Ｍｎ２＋浓度及其扩散特征的不同是由其氧化还原速率、扩散速度、控制体系及其氧化还原环境共同作用的结果。 湖沉积物以粗粉砂为主，为还原特征；礁外沉积物以粉砂质粘土软泥为主，为弱还原特征，从间隙水中Ｆｅ２＋，Ｍｎ２＋浓度，Ｍｎ／Ｆｅ值及其礁外／ 湖值，Ｆｅ２＋，Ｍｎ２＋界面扩散及其Ｍｎ／Ｆｅ值，沉积物氧化还原度（ＲＯＤ）的研究得到一致的结论，南沙群岛海区湖沉积物的还原性比礁外沉积物强。 相似文献
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山东省常见海产品蛋白质氨基酸含量分析 总被引：5，自引：2，他引：3
海产品蛋白质的营养价值及风味均与氨基酸含量有很大关系,为了更好地了解山东沿海地区蛋白质营养状况,根据山东沿海地区食物资源特点,作者采集了沿海地区常食用的２０余种海产品进行了蛋白质氨基酸分析,结果如下。１ 材料和方法１．１ 材料采自山东沿海地区新鲜海产品。１．２方法［１］１．２．１蛋白质的测定 以粗蛋白表示。以凯氏微量定氮法（Ｋｊｅｌｄａｈｌ法）测定总氮量,再乘一定的数值（转换系数为６．２５）,即为蛋白质质量。１．２．２氨基酸的测定 用氨基酸自动分析仪法完成。食物蛋白质经盐酸水解成为游离氨基酸后根… 相似文献
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首次用新研制的高精密磁力浮沉子密度计测定ＮａＨＣＯ３，ＫＢｒ，ＫＮＯ３和Ｃａ（ＮＯ３）２在盐度为３０．０和３４．７温度为２９８、１０Ｋ时的偏摩尔体积（即ｐｍｖ）。重新测定了ＮａＣｌ，ＫＣｌ．Ｎａ２ＳＯ４和ＭｇＳＯ４在海水中的ｐｍｖ，并用实验精密验证了海水中主要电解质的ｐｍｖ的加和性关系。 相似文献
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磷作为海洋浮游生物生长必需营养元素之一,其准确测定对海洋生态系统元素循环过程的研究具有重要意义。目前,文献中对于海洋浮游生物中总磷的测定方法报道不多。由于海洋浮游生物生存的高盐海洋环境,高盐基体的存在导致常规检测方法不能准确测定磷的含量。为剔除高盐基体效应及干扰,本文运用微波密闭消解预处理样品,采用电感耦合等离子体发射光谱法(ICP-OES)联合标准加入法建立工作曲线,同时结合样品的特异性,对ICP-OES分析谱线、射频功率、雾化气流速、观测高度、蠕动泵泵速和观测方式等仪器参数进行优化,构建确定了准确测定海洋浮游生物中总磷的优化条件和技术流程。实验结果显示, ICP-OES最佳工作条件为分析谱线P213.617 nm,射频功率1 300 W,雾化气流量0.8 L/min,观测高度14mm,进样泵速1.5 m L/min,观测方式轴向。标准加入法标准曲线相关系数大于0.999,相对标准偏差为1.36%~1.67%,加标回收率为92.6%~94.3%,方法检出限为0.010 mg/L,检测结果具有较高的准确度和精密度,可为海洋浮游生物及其它高基体生物样品中磷含量的准确测定提供技术支持。 相似文献
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Tiit Kutser Ele Vahtme Chris M. Roelfsema Liisa Metsamaa 《Estuarine, Coastal and Shelf Science》2007,75(4):559-563
The creation of seagrass biomass maps by diving/snorkelling is time-consuming and expensive. This paper presents a method for estimating seagrass dry weight using a photo-library of classes of differing seagrass biomass. Field data were collected at seagrass beds in Ngederrak Reef, Palau, in 2006. Photos of 25 × 25 cm quadrats were taken prior to the collection the above-ground biomass for determination of biomass dry weight. Fifteen classes of seagrass biomass and substrate type were identified. The dry weight for each class of seagrass was measured in laboratory. A photo-library was created for biomass classification where each in situ quadrat photo is accompanied with seagrass dry weight of the sample and a photo of the sorted sample taken in laboratory. The photo-library of quadrats was then used to estimate seagrass biomass on photos gathered along 100 m long transects at 2 m intervals. This procedure was conducted by three different observers. The seagrass dry weight estimates were consistent between interpreters even if one of the interpreters had no experience in seagrass research. This approach allows quick collection of seagrass dry weight data over large areas. The method can be used for creating seagrass biomass maps by snorkelling/diving and/or for calibrating and validating biomass maps created by remote sensing. 相似文献
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The molecular size distribution of humic substances has been investigated in two recent sediment samples of different ages taken from a single core sample collected off Walvis Bay, south-west Africa. Extractable humic acids were found to be by far the major form of organic carbon in both sediments, the near-surface younger sample containing predominantly high molecular weight (>100 000 molecular weight) humic acids and little fulvic acids whilst the deeper, older sample contained relatively less humic acid and relatively more fulvic acid of a range of molecular weights. A significant age difference was found between the >300 000 molecular weight and the <30 000 molecular weight fractions of the near-surface sample, the lower molecular weight fraction being older than the higher molecular weight fraction.The data suggest that in this rapidly accumulating, organic-rich sediment the first step en route from the planktonic matter to the humic complexes is direct and rapid incorporation of the biogenic material into high molecular weight humic acids. 相似文献
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Taitiro Fujinaga Tooru Kuwamoto Eiichiro Nakayama Shinji Tanaka 《Journal of Oceanography》1980,36(4):196-200
A precise and accurate technique for the determination of Li and Rb in sea water has been developed by using a double channel flame emission spectrophotometer. The advantage of this technique is that it is possible to correct the background emission by making use of the double channel system of the apparatus and to obtain constant intensity of emission even if there are large scale changes in the salinity of the sample. Sea water samples collected in the open sea and coastal areas of Japan were analyzed by this method. In one of the coastal areas, an extraordinarily high concentration of Li was found. 相似文献
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Anoop A. Krishnan K.S. Yousuf P.L. Kumaran N. Harish B. Anoop V.V. Afsal M. Rajagopalan E. Vivekanandan P.K. Krishnakumar P. Jayasankar 《Estuarine, Coastal and Shelf Science》2008,76(4):909-913
The stomachs of 32 individuals of seven cetacean species incidentally caught in gill net and purseseine fisheries along Mangalore and Chennai coasts (India) between 2004 and 2006 were examined. The whole stomach (fore-gut, mid-gut and hind-gut) was examined in all cases. Prey remains (666 prey items comprising six species of teleosts, one crustacean and one squid species) were found in the stomachs of eight individuals (the remaining 24 stomachs were found to be empty). All cetaceans were found to feed mostly on teleosts with wide range of trophic levels. Based on an index that included frequency of occurrence, percentage by number and by weight, the oil sardine Sardinella longiceps was the main prey in the sample. Cetaceans appear to favour both pelagic as well as demersal prey, possibly indicating surface and benthic feeding habits. 相似文献
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Uplift capacity of circular piles in sands is one important design parameter for many pile foundations supporting important structures subjected to tensile forces. Even though a number of formulas based on the limit equilibrium or semi-empirical methods are proposed to predict the uplift capacity of piles in sands, there is a major limitation of the methods in obtaining the accurate predictions. In this paper, the computational limit analysis is employed to investigate the uplift capacity of circular piles in sands. The effects of the important variables including pile length and diameter, soil friction angle and unit weight, and roughness factor at soil-pile interface are examined extensively using the dimensionless parameters while the predicted failure mechanisms associated with the parameters are discussed and compared. Approximate statistical design equations of the uplift capacity of circular piles in sands are developed based on the numerically derived solutions and the existing experimental data. It is found that the proposed design equations provide the most accurate prediction of the uplift capacity of circular piles in sands as compared to the existing formulas. 相似文献
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新鲜海带中碘的含量与分布 总被引：1，自引：0，他引：1
海带中含有高浓度的碘是其独特的化学组成特点,历来被海藻学家所重视(Tang and Chang, 1935, 1936; Black, 1948, 1949; Klemperer, 1957; Fernandez et al., 1964:Dave et al., 1973; Law, 1975; Solimabi and Das, 1977; Yamamoto et al., 1984:Doshi and Joshi,1989; Mairh et al.,1989),但是几乎所有的有关研究方法都基于化学滴定,在材料上局限于海藻干品,另外海带样品含有大量的褐藻多糖以及多酚类化合物,能够包溶部分碘离子及碘单质,因此用常规的化学滴定法误差较大,从而导致试验结果的非重复性和非可靠性。本文利用碘离子选择电极法,直接在样品溶液中测定,不必经过离心、氧化还原等一系列复杂的步骤,测定了新鲜海带中不同部位碘的含量和分布,为进一步研究海带中碘的化学存在形态提供了理论数据。 相似文献