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讨论了~936)Cl的成因、~(36)Cl断代法的原理及测试方法。自1987年以来,应用该方法测得柴达木盆地尕斯库勒湖和大浪滩湖石盐的沉积年龄,并与~(14)C,~(230)Th和古地磁测年法所测得的年龄数据进行对比,结果均在误差(1δ)范围内相吻合,表明石盐的~(36)Cl断代法是可行的,获得的年龄数据是可靠的。 相似文献
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本文根据华南沿海各地全新世海相、滨海相沉积物的~(14)C断代数据、海拔高程及其所构成地貎体的特征,探讨了该区全新世以来的海陆变迁。 相似文献
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蔡莲珍 《海洋地质与第四纪地质》1992,12(2):103-112
本文阐述了经常开展~(14)C测定的互校对比活动和推行质量保证制度的重要意义。从国内外多次对比结果中存在的问题指出:建议应积极参加国际对比活动,进一步开展国内对比活动和质量保证制度,以期广泛提高全国~(14)C测试水平。这些建议不仅有利于~(14)C实验室本身建设而且对有关学科研究水平的提高同样重要 相似文献
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沉积物中碳酸盐~(14)C年龄的可靠性 总被引：1，自引：0，他引：1
本文根据放射性碳杂志上发表的300余个~(14)C年龄数据及在中国和澳大利亚进行的野外调查,对土壤碳酸盐的形成途径,稳定同位素成份,钙结核的生长速率及古气候效应等问题进行了讨论.可区别出的三个δ~(13)C丰值,看来与环境和碳的来源无关.而土壤碳酸盐~(14)C年龄分布频率揭示它们形成于相对温暖-潮湿的古气候期.“老碳”的混入及土壤碳酸盐缓慢的生长速率是主要的误差来源.δ~(13)C值不能用于校正土壤碳酸盐的~(14)C年龄. 相似文献
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本文根据南海中部海区17个样品的~(14)C年龄测定结果,叙述了深海沉积物的~(14)C测年方法和步骤;同时对南海中部深海沉积物中生物碳酸盐中的无机碳和有机碳所测定的~(14)C年龄差别进行了讨论。认为南海中部深海沉积物中的无机碳~(14)C年龄偏老于有机碳的~(14)C年龄,但偏老程度不大。认为有机碳的~(14)C年龄是可靠的。 相似文献
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本文着重论述应用锂法对我国几个海区和陆地的地质钻孔样品进行~(14)C断代的实验流程,同时报道了1985年和1986年期间我实验室用液烁仪测出的部分样品的年代数据。最后论述了为提高合成苯的产率在实验中应采取的必要措施。 相似文献
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用14C法测定海洋初级生产力 总被引：1，自引：0，他引：1
测定海洋初级生产力有好几种方法,如测氧法、叶绿素法、磷酸盐法、颗粒计算法、测氚法和放射性碳-14法等。但就方法的灵敏度、准确性而言,用~(14)C法测定水域初级生产力被认为是最好的方法,尤其是用来进行大洋初级生产力的调查更显出其优越性。因此,用~(14)C 相似文献
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静态集合样本的构造及其在全球海浪滤波同化中的应用 总被引：4，自引：2，他引：2
本文提出一种最佳静态集合样本的构造方法,利用不同时段内海浪有效波高的模拟偏差构造静态集合样本,并将其与由模拟结果和观测资料统计的模式误差进行概率密度分布及时空相关性分析,结果表明24h间隔有效波高偏差与后者的相关性最好,称为最佳静态集合样本,可用于近似背景误差。将所构造的静态集合样本应用于滤波同化调整过程,采用MASNUM海浪模式,利用Jason-1卫星高度计数据,对2008年全球海域开展海浪同化实验,实验结果表明,基于最佳静态集合样本的海浪同化调整,可以有效地改善海浪模式的模拟效果。 相似文献
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A prototype deep pump filtration system, designed to sample suspended particulate matter in the deep sea, has been developed for use with an in-situ optical nephelometer used to locate zones of high particulate concentration. The filtration system, which has essentially an unlimited depth capability, can sample large volumes of water and is limited only by the concentration of the suspended load and the clogging characteristics of the filter, thereby being ideally suited for use in areas of extremely low particulate concentration. In its present configuration, the unit is capable of collecting as much as 200 mg of suspended sediment per lowering. The system is compact in design and may easily be integrated with any instrument platform, or used independently. In addition, the membrane filtration method utilized provides a convenient means of sample handling during analysis with a minimum of contamination. 相似文献
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Jonathan H. Sharp 《Marine Chemistry》1973,1(3):211-229
A method is described for the determination of organic carbon in liquid seawater samples by combustion at a high temperature. Although the method is not easy to perform, it has been successfully employed for a direct comparison to the standard method of persulfate oxidation. With seawater from the central western North Atlantic Ocean, the standard method measured an average of 78% as much carbon as the high temperature method. This indicates organic matter in seawater that is resistant to oxidation by persulfate; some of it appears to be of a colloidal nature. The persulfate resistant organic matter is most noticeable in a region below the surface 100 m and seems to decrease slowly with depth, indicating deep ocean biological utilization of organic matter. Due to a possible procedural error in the standard persulfate oxidation method, the differences indicated here may actually be conservative and the content of total organic carbon in the sea may be as much as twice as high as has been indicated by previous estimates. 相似文献
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从重力场匹配导航的改进 TERCOM 算法入手,针对采样长度、采样间隔以及重力测量误差对匹配结果的影响进行了系统的分析,并在此基础上设计了客观有效的准实时仿真试验,结果表明:(1)采样长度对匹配结果有重要的影响,匹配长度过短或过长都不利于匹配到最佳格网位置,当采样长度与重力基准图的分辨率比值在 10 ~ 20 之间时,能够获得较好的匹配效果;(2)在采样长度一定的情况下,适当增加采样间隔可以在一定程度上提高匹配的整体精度;但采样间隔增加到一定程度后,继续增加采样间隔将引起匹配效果急剧恶化;(3)重力测量白噪声误差对匹配结果影响相对较大,但 5mGal 以内的重力测量白噪声对都能够进行有效匹配;而在重力测量误差受高斯白噪声和系统性误差同时作用的情况下,过大的系统性误差将不能得到有效匹配。 相似文献
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卫星遥感业务系统海表温度误差控制方法 总被引：11，自引：1，他引：11
提高卫星遥感海表温度的反演精度是各种反演模型追求的目标,也是遥感系统业务化应用的关键.据相关文献报道,在晴空无云的条件下遥感海表温度的精度达到了0.5℃,但考虑到影响海表温度反演精度的多种因素,在遥感业务系统真正实现SST精度在1℃以内是非常困难的.在北太平洋渔场速报制作系统中,对遥感海表温度与船测温度误差统计显示均方根误差达到5.71℃,匹配点误差分布显示存在大量较大的负误差值,最大的为-17.2℃,遥感温度图也反映出存在片状温度低值区,这些区域很可能被错误地当作冷涡或冷锋区,严重干扰渔情分析,这些异常的温度误差很难通过海表温度反演模式和云检测技术来消除.采用一种标准海表温度参考图用于温度误差控制技术,可有效地检测温度反演异常值,将均方根值从5.71℃降低到1.75℃,如果采用2℃阈值控制计算均方根值,则海表温度精度达到0.785℃.该方法基本消除了遥感海表温度的低值现象,明显提高了遥感海表温度的精度,并已成功地应用于北太平洋渔区的海况速报产品制作中. 相似文献
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Brumley B.H. Cabrera R.G. Deines K.L. Terray E.A. 《Oceanic Engineering, IEEE Journal of》1991,16(4):402-407
A new broadband acoustic Doppler current profiler (ADCP) is described, with a useful range comparable to that of a commercially available narrowband (incoherent) system of the same acoustic frequency, but having enhanced performance. The extra performance may be traded off among (1) reduced velocity variance, (2) reduced averaging time, and (3) finer depth resolution. This improvement permits the observation of phenomena with smaller time and space scales than is now possible with available ADCPs. An expression predicting r.m.s. velocity error in terms of system parameters and the measured acoustic data is given and is shown to be consistent with the independently measured velocity error among redundant beams. Two major sources of bias error in incoherent ADCPs are shown to be much reduced for the broadband system. Field data demonstrating the improved performance over the existing incoherent ADCP are shown for cases of both strong and weak shear 相似文献
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风暴潮是一种复杂的对众多因素敏感又备受关注的海洋现象。本文基于协方差局地化的集合卡尔曼滤波方法（EnKF）,选择201810号台风“安比”登陆上海的风暴潮过程,首次将海洋站和FVCOM数值模拟的不同来源、不同误差信息、不同时空分辨率的风暴潮进行数据同化融合,获得了逐72 h的上海海域风暴潮的最优解,进行了同化结果评估验证,并给出了集合样本数和Schur半径设置范围。结果表明,实测计算和数值模拟的风暴增减水之间均方根误差为0.20 m,实测和同化计算的风暴增减水之间均方根误差为0.07 m,准确度提高了65%;独立观测和同化计算的风暴增减水均方根误差为0.09 m,集合离散度与均方根误差比值为0.90,同化效果较好且可信;同化后的风暴增减水能够较好地刻画双峰增水、台风眼增水、增水锋面等特征,对于风暴潮研究、数值模拟结果订正、海洋防灾减灾等有重要意义。 相似文献
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The Eulerian?Lagrangian method (ELM) has been used by many ocean models as the solution of the advection equation, but the numerical error caused by interpolation imposes restriction on its accuracy. In the present study, hybrid N-order Lagrangian interpolation ELM (LiELM) is put forward in which the N-order Lagrangian interpolation is used at first, then the lower order Lagrangian interpolation is applied in the points where the interpolation results are abnormally higher or lower. The calculation results of a step-shaped salinity advection model are analyzed, which show that higher order (N=3?8) LiELM can reduce the mean numerical error of salinity calculation, but the numerical oscillation error is still significant. Even number order LiELM makes larger numerical oscillation error than its adjacent odd number order LiELM. Hybrid N-order LiELM can remove numerical oscillation, and it significantly reduces the mean numerical error when N is even and the current is in fixed direction, while it makes less effect on mean numerical error when N is odd or the current direction changes periodically. Hybrid odd number order LiELM makes less mean numerical error than its adjacent even number order LiELM when the current is in the fixed direction, while the mean numerical error decreases as N increases when the current direction changes periodically, so odd number of N may be better for application. Among various types of Hybrid N-order LiELM, the scheme reducing N-order directly to 1st-order may be the optimal for synthetic selection of accuracy and computational efficiency. 相似文献