Research on multiple elimination methods in inverse data space based on randomized singular value decomposition

Based on surfaced-related multiple elimination (SRME),this research has derived the methods on multiples elimination in the inverse data space.Inverse data processing means moving seismic data from forward data space (FDS) to inverse data space (IDS).The surface-related multiples and primaries can then be separated in the IDS,since surface-related multiples will form a focus region in the IDS.Muting the multiples energy can achieve the purpose of multiples elimination and avoid the damage to primaries energy during the process of adaptive subtraction.Randomized singular value decomposition (RSVD) is used to enhance calculation speed and improve the accuracy in the conversion of FDS to IDS.The synthetic shot record of the salt dome model shows that the relationship between primaries and multiples is simple and clear,and RSVD can easily eliminate multiples and save primaries energy.Compared with conventional multiples elimination methods and ordinary methods of multiples elimination in the inverse data space,this technique has an advantage of high calculation speed and reliable outcomes.     

Evidence for Systemic Changes in the Benthic Fauna of Tropical Estuaries as a Result of Urbanization

The effects of urban development cause substantial physical changes in coastal waterways through hardening and reclamation of river banks, alteration of water flow, and diffuse and point-source discharges of pollutants. The cumulative effects of urbanization on the fauna of estuaries are not well understood. This study examined the benthic infauna of two urban and three rural estuaries near Townsville, North Queensland. A range of univariate and multivariate statistics was used to relate variation in the benthic assemblages to concentrations of contaminants (heavy metals and hydrocarbons) within the sediments of each estuary. Sediments in the most developed estuary contained concentrations of heavy metals and petroleum hydrocarbons that were several orders of magnitude greater than those from non-urban waterways. The fauna at these sites was dominated by cirratulid and sternaspid polychaetes and lacked filter-feeding bivalves and other molluscs that were common in less developed estuaries. These differences were generally consistent throughout each estuary, indicating estuary-wide patterns of change, that were most strongly associated with spatial patterns in the distribution of Pb, Cu and hydrocarbons.     

麦地复播玉米及其青贮研究

麦地复播玉米 ,以新玉— 7号较好 ,施尿素 30 0kg/hm2 时其产量最高 ,在秋季重霜来临之前收割玉米茎杆进行青贮 ,40天后可饲用     

Derivatives of Spatial Variances of Growing Windows and the Variogram

Geostatistical analysis of spatial random functions frequently uses sample variograms computed from increments of samples of a regionalized random variable. This paper addresses the theory of computing variograms not from increments but from spatial variances. The objective is to extract information about the point support space from the average or larger support data. The variance is understood as a parametric and second moment average feature of a population. However, it is well known that when the population is for a stationary random function, spatial variance within a region is a function of the size and geometry of the region and not a function of location. Spatial variance is conceptualized as an estimation variance between two physical regions or a region and itself. If such a spatial variance could be measured within several sizes of windows, such variances allow the computation of the sample variogram. The approach is extended to covariances between attributes that lead to the cross-variogram. The case of nonpoint sample support of the blocks or elements composing each window is also included. A numerical example illustrates the application of this conceptualization.     

广义相对论框架中的IAU时间尺度和参考系

简要地回顾和介绍了IAU时间尺度和参考系的历史和进展，其主要内容：（1）牛顿时空观和相对论时空观，（2）IAU各种时间尺度的历史演变和相互关系；（3）IAU的天文参考系，有关的最新决议,相对论框架下度规及其规范问题，四维时空中的空间1PN坐标变换，也介绍了一些有关工作，阐明了与IAU最新决议稍有不同的观点，指出目前IAU有关决议可能仍存在的某种程度上的不完善。     

On multiple solutions to a low-spectrum model of oceanic current driven by the boundary force—The bimodality of the Kuroshio south of Japan

This low-spectrum model study on the multiple solutions to a nonlinear quasi-geostrophic oceanic current equation shows that they depend on the combination ofRo, Re, λ and ε, that the bimodality of the Kuroshio depends strongly on the nonlinear effect represented byRo and λ, and that its occurrence probability is reduced by the dissipation represented byRe and ε. The stability of solutions is discussed in detail with Hurwitz's theory. This work was supported by NSFC (No. 49070252)     

西太平洋西北海域海温与西副高和极涡的联系

本文通过西太平洋西北部海表温度与北半球500hpa西副高和极涡环流指数的典型相关分析,得到了一些有意义的环流超前与滞后的相关事实,证实了环流有3—6个月的滞后相关的存在。     

Implications for improving paleolimnological inference models utilizing scale-bearing siliceous algae: transforming scale counts to cell counts

Microfossil remains of siliceous scale-bearing members of the Synurophyceae and Chrysophyceae have become of increasing importance in paleolimnological studies, especially ones involving the reconstruction of historical lakewater pH. Since the numbers of scales per cell for individual taxa are not known, inference models have been based on the relative abundances of scales, not cells. Theoretically, inference models based on the relative numbers of cells would be more appropriate. Morphometric characteristics of scales and cells were used to estimate the mean numbers of scales per cell for 38 taxa. The mean numbers of scales per cell ranged from a low of 27 to a high of 214; over 80% of the taxa had fewer than 100 scales per cell. A highly significant model for estimating the numbers of scales per cell was developed based on scale and cell surface area measurements. The application of the model in order to estimate the number of scales per cell for additional taxa, or ones found to have different morphometric measurements, is discussed.     

三步组合法衰减深水多次波

深水地震资料多次波具有能量强、周期长的特点,降低了资料的信噪比,是处理人员面临的首要问题。多次波衰减效果的好坏,直接影响着最终成像效果及后期储层反演结果的真实性。分析深水多次波的类型、成因和特征,并研究各种多次波衰减技术的优缺点和适用性,最终合理组合多方法、分步衰减多次波是关键。以南海A区深水地震资料为例,通过组合优选基于模型的SRME技术和高分辨率Radon技术进行了实际应用,并就出现的剩余多次波给予分析和改进,提出了“三步法”衰减深水多次波,应用后取得了显著的多次波衰减效果。     

斑节对虾形态性状对体质量影响的分析

经济性状是对虾遗传育种的重要指标, 形态参数对于经济性状的贡献率是选育参数的重要依据。为了研究斑节对虾(Penaeus monodon)表型性状间的相关性及影响体质量的因素组成, 随机选取1 339 尾6 月龄对虾, 对其形态性状(体长、头胸甲长、头胸甲高、头胸甲宽)和体质量性状5 个数量性状进行测量, 并应用相关分析、多元回归、通径分析、决定系数等方法讨论了形态性状对体质量性状的影响。结果表明, 所测各形态性状间的相关性均达到极显著水平(P<0.01); 其中体长(P=0.563)对体质量的直接影响较大, 是影响体质量的主要因素。决定系数分析结果与通径分析结果一致, 各表型性状对体质量的总决定系数Σd=0.925, 表明所选性状是影响体质量的主要性状。通过逐步回归分析方法,经偏回归系数显著性检验, 建立了体质量为因变量, 体长、头胸甲长、头胸甲高和头胸甲宽为自变量的多元回归回归方程:Y= –22.489 + 0.22X₁+ 0.191X₂+ 0.339X₃+ 0.296X₄, 为斑节对虾选育提供了理论依据。