关于t-模的生成

讨论了概率度量空间中ｔ－模生成的概率意义。对构造ｔ－模提供了具体方法，并以实例介绍了这种构造方法。     

Alluvial architecture of the Holocene Rhine–Meuse delta (the Netherlands)

Ancient fluvial successions often act as hydrocarbon reservoirs. Sub‐surface data on the alluvial architecture of fluvial successions are often incomplete and modelling is performed to reconstruct the stratigraphy. However, all alluvial architecture models suffer from the scarcity of field data to test and calibrate them. The purposes of this study were to quantify the alluvial architecture of the Holocene Rhine–Meuse delta (the Netherlands) and to determine spatio‐temporal trends in the architecture. Five north–south orientated cross‐sections, perpendicular to the general flow direction, were compiled for the fluvial‐dominated part of the delta. These sections were used to calculate the width/thickness ratios of fluvial sandbodies (SBW/SBT) and the proportions of channel‐belt deposits (CDP), clastic overbank deposits (ODP) and organic material (OP) in the succession. Furthermore, the connectedness ratio (CR) between channel belts was calculated for each cross‐section. Distinct spatial and temporal trends in the alluvial architecture were found. SBW/SBT ratios decrease by a factor of ca 4 in a downstream direction. CDP decreases from ca 0·7 (upstream) to ca 0·3 (downstream). OP increases from less than 0·05 in the upstream part of the delta to more than 0·25 in the downstream delta. ODP is approximately constant (0·4). CR is ca 0·25 upstream, which is approximately two times larger than in the downstream part of the delta. Furthermore, CDP in the downstream Rhine–Meuse delta increases after 3000 cal yr BP. These trends are attributed to variations in available accommodation space, floodplain geometry and channel‐belt size. For instance, channel belts tend to narrow in a downstream direction, which reduces SBW/SBT, CDP and CR. Tectonics cause local deviations in the general architectural trends. In addition, the positive correlation between avulsion frequency and the ratio of local to regional aggradation rate probably influenced alluvial architecture in the Rhine–Meuse delta. The Rhine–Meuse data set can be a great resource when developing more sophisticated models for alluvial architecture simulation, which eventually could lead to better characterizations of hydrocarbon reservoirs. To aid such usage of the Rhine–Meuse data set, constraints for relevant parameters are provided at the end of the paper.     

Flood hazard delineation combining geomorphological and hydrological methods: an example in the Northern Iberian Peninsula

Flood mapping requires the combination and integration of geomorphological and hydrological-hydraulic methods; however, despite this, there is very little scientific literature that compares and validates both methods. Two types of analysis are addressed in the present article. On the one hand, maps of flood plains have been elaborated using geomorphological evidence and historical flood data in the mountainous area of northwestern Spain, covering an area of more then 232 km² of floodplains. On the other hand, a hydrometeorological model has been developed (Clark semidistributed unit hydrograph) in the Sarria River basin (155 km², NW Spain). This basin is not gauged, hence the model was subjected to a goodness-of-fit test of its parameter (curve number) by means of Monte Carlo simulation. The peak flows obtained by means of the hydrological model were used for hydraulic modeling (one-phase, one-dimensional and steady flow) in a 4 km² urban stretch of the river bed. The delineation of surface areas affected by floods since 1918, as well as those analyzed subsequent to the geomorphological study, reveals a high degree of reliability in the delineation of the flooded areas with frequent recurrence intervals (<50 years). If we compare these flooded surface areas with the estimate obtained by the hydrological-hydraulic method we can see that the latter method overestimates the extent of the surface water by 144% for very frequent recurrence intervals (>10 years) and underestimates it as the recurrence interval increases, by up to 80% less floodplain for exceptional events (>500 years). Finally, a management map is put forth combining the most reliable results available by integrating both methods. Originally presented at the Sixth International Conference on Geomorphology.     

复合酶法制备鯷鱼活性寡肽的研究

探讨了用复合酶法制备鱼是鱼活性寡肽及其氨基酸组成和相对分子质量分布情况。应用正交试验法研究了酶量、酶解温度、酶解时间对鱼是鱼蛋白质水解度和酶解液苦味的影响。结果表明,最佳酶解作用条件是:酶量为100u/mL;酶解温度为50℃;酶解时间为4h。此时的酶解液苦味较低,水解度可达62.81%。应用氨基酸分析仪和凝胶排阻高效液相色谱分析了该寡肽的氨基酸组成和相对分子质量的分布范围,其十肽以下的小肽占67.77%,氨基酸组成平衡,必需氨基酸含量丰富。鱼是鱼活性寡肽有望成为保健食品、医药等领域的新型高品质原料。     

非量测数码相机（哈苏H1D型）在南极项目生产中的应用

简要分析了非量测数码相机哈苏H1D在南极中山站及拉斯曼丘陵地区所获取的影像数据的几何精度,阐明了利用该影像数据进行空中三角测量,DLG,DOM制作的技术流程及作业过程中出现问题的处理方法。     

Understanding Perturbation on the Simplex: A Simple Method to Better Visualize and Interpret Compositional Data in Ternary Diagrams

Perturbation is an operation defined on the simplex and can be used for centering compositional data in a ternary diagram, applying objective criteria. Because a straight line in the original diagram is still astraight line in the perturbed diagram, gridlines or compositional fields defined by straight lines can easily be included in the operation. Simultaneous perturbation of data, gridlines, and/or compositional fields is shown to improve both visualization and graphical interpretation of compositions in ternary diagrams. This is illustrated by some examples using simulated as well as real data.     

Relation of the Wave-Propagation Metric Tensor to the Curvatures of the Slowness and Ray-Velocity Surfaces

The contravariant components of the wave-propagation metric tensor equal half the second-order partial derivatives of the selected eigenvalue of the Christoffel matrix with respect to the slowness-vector components. The relations of the wave-propagation metric tensor to the curvature matrix and Gaussian curvature of the slowness surface and to the curvature matrix and Gaussian curvature of the ray-velocity surface are demonstrated with the help of ray-centred coordinates.     

Compositional Geometry and Mass Conservation

A geometrical structure is imposed on compositional data by physical and chemical laws, principally mass conservation. Therefore, statistical or mathematical investigation of possible relations between data values and such laws must be consistent with this structure. This demands that geometrical concepts, such as points that specify both mass and composition in linear space, and lines in projective space that specify composition only, be clearly defined and consistent with mass conservation. Mass thus becomes the norm in composition space in place of the Euclidean norm of ordinary space. Coordinate transformations inconsistent with this geometry are accordingly unnatural and misleading. They are also unnecessary because correlation arising from the constant mass presents no unusual difficulty in the analysis of the underlying quadratic form.     

北京连续降雪过程分析

该文对2002年12月份北京出现的1841年以来历史上最长的连续6天的降雪天气进行了合成分析和诊断分析。北半球合成环流形势显示，连续降雪发生在东亚稳定的纬向环流形势下，其上游地区强大经向环流和阻塞高压使中纬度东亚和西太平洋纬向环流得以维持。东亚合成环流的垂直结构表明，连续降雪期间华北地区始终处于锋区中，并存在低空辐合、高空辐散的散度场垂直分布结构。卫星水汽云图显示出有水汽通道向河套倒槽云系输送水汽。华北地区的诊断分析表明，地面和边界层中山东地区分裂高压南侧向北回流的偏南气流是造成降雪的主要水汽通道。变形场的流场结构使水汽在北京附近辐合。垂直剖面展现了华北回流降雪天气近地面层的浅薄的冷空气垫，和暖湿空气回流在冷空气垫上的爬升，并在其上形成一个浅薄的饱和层。