运用nrDNA ITS 数据研究角叉菜属(Chondrus)在红藻门中的系统进化地位

测定了角叉菜属(Chondrus)5个代表种的核糖体DNA内转录间隔区(ITS)及5.8SrDNA基因序列。结果表明,角叉菜属ITS区(含ITS1、5.8SrDNA和ITS2)序列长度范围为704—714bp,G+C含量为44.6%—45.7%,变异位点69个,信息位点16个;其中,ITS1和ITS2的长度范围分别为147—149bp和398—404bp。5.8SrDNA长度为158bp,没有变异和信息位点。由MEGA3构建的系统进化树(ME和MP)显示:在进化尺度上,真红藻纲的松节藻科(Rhodomelaceae)与红毛菜纲(Bangiophyceae)亲缘关系较近。在真红藻纲内,杉藻目(Gigartinales)的进化地位相对较高,其次是海膜科(Halymeniaceae)、石花菜科(Gelidiaceae)、红叶藻科(Delesseriaceae)和粉枝藻科(Liagoraceae)等,而松节藻科进化地位相对较低。在杉藻目内,杉藻科(Gigartinaceae)和胶黏藻科(Dumontiaceae)进化关系密切,而形态学特征相似的角叉菜和马泽藻(Mazzaella)亲缘关系非常近。     

试论我国现代地图学发展及其学科体系

现代地图学空间活跃，发展迅速，并在我国科技领域和国民经济建设中发挥着积极的作用。它已经成为一门涉及多领域的综合性学科。本文在分析现代地图学发展特点基础上，运用系统科学方法论，对现代地图学及其学科体系进行系统分析，提出了现代地图学学科体系的基本框架和对我国现代地图学发展及建立学科体系的几点认识和建议。     

前兆信息的系统结构及其在地震综合预报中的应用

本文讨论了地震前兆信息的系统结构．指出了系统结构在系统整体上获得信息增益的作用，并用层次分析法来确定系统结构矩阵。通过在滇西地区的实际应用，表明前兆信息的系统结构对地震综合预报具有一定意义。     

我国国家重力网的系统转换

本文分析了我国１９５７年国家重力网的精度和问题，探讨了国家重力网的系统转换模式，利用现有的新旧重力网的重合点实际数据进行了回归分析、方差分析和系统误差检验，结果表明在“５７网”与“８５网”之间，除了—１３．５８ｍｇａｌ的平均基准差之外，并不存在其它明显的系统误差，特别是看不出有尺度系统差的影响，也不存在差值随纬度变化的任何规律。因此认为将“５７网”系统转换成“８５网”系统时，可以不必加“尺度系统差改正”，更不用考虑“非线性系统差改正”，建议一律只加一项“基准系统差改正”，其数值应该采用—１３．５８ｍｇａｌ。     

Uncertainty in GPS Networks due to Remaining Systematic Errors: The Interval Approach

A realistic assessment of the total uncertainty budget of Global Positioning System (GPS) observations and its adequate mathematical treatment is a basic requirement for all analysis and interpretation of GPS-derived point positions, in particular GPS heights, and their respective changes. This implies not only the random variability but also the remaining systematic errors. At present in geodesy, the main focus is on stochastic approaches in which errors are modeled by means of random variables. Here, an alternative approach based on interval mathematics is presented. It allows us to model and to quantify the impact of remaining systematic errors in GPS carrier-phase observations on the final results using deterministic error bands. In this paper, emphasis is given to the derivation of the observation intervals based on influence parameters and to the study of the complex linear transfer of this type of uncertainty to estimated point positions yielding zonotopes. From the presented simulation studies of GPS baselines, it turns out that the uncertainty due to remaining systematic effects dominates the total uncertainty budget for baselines longer than 200 km.     

Numerical simulation of ground anchors

A procedure of finite-element modeling and beam-column modeling of ground anchors was proposed in this study to investigate the load transfer mechanism in ground anchors. The procedure included the modeling of soil, grout, and strand tendon and the interface modeling of soil–grout and grout–strand in ground anchors. A series of finite element analyses and beam-column analyses were performed using the proposed models on ground anchors. The numerical predictions were compared with observed measurements in a field load test. The results indicated that the numerical simulation of load transfer mechanism on ground anchors can provide reasonable predictions.     

Affine distortion of small GPS networks with large height differences

GPS is a promising tool for real-time monitoring of deformations of slopes or large structures. However, remaining systematic effects in GPS phase observations after double differencing and application of a priori models affect the resulting coordinates. They complicate the proper separation of the actual deformations from pseudo-deformations induced by the systematic effects. This paper shows that for small monitoring networks (baseline lengths <5 km) only affine distortions of the network geometry are generated by the remaining distance dependent systematic effects, e.g. unmodelled tropospheric and ionospheric propagation effects, or satellite orbit errors. Hence, a generic correction model is given by a three-dimensional affine transformation involving a maximum of 12 transformation parameters. For the determination of these parameters, four high quality GPS stations are necessary which are not affected by the actual deformations to be monitored. Based on the analysis of network geometries of synthetic GPS networks with large height differences and considering the physics of the GPS observations it is shown, however, that less than 12 parameters are sufficient for the computation of the corrections. The proposed 8 parameter model was applied to the GPS monitoring network of the Gradenbach landslide. For this small network with large height differences, it was shown that the distortions can be reduced by about 75%.     

Some foundation stability problems of the railway bridge over the Mala Rijeka

SummarySome Foundation Stability Problems of the Railway Bridge over the Mala Rijeka The authors presented an outlay of problems occurring in estimating the stability of rocky slopes loaded by large vertical forces. General attitudes, kept by the authors during the stability analysis for an actual case — foundation of piers No. 3 and 4 of the railway bridge across the Mala Rijeka, are also presented. The results of calculation as well as the advantages of the approach applied are outlined in the paper. Finally, general conclusions are drawn regarding the method to be kept in solving the stability of slopes loaded by large artificial loading.With 7 Figures     

卡尔曼滤波器在卫星遥感影像大地校正中的应用

在卫星遥感图像的预处理中,通过系统校正可以基本上消除影像内部的变形误差。然而,整幅影像的大地定位误差仍然是很大的,甚至几百米至1公里的数量级。本文介绍利用少量的地面控制点,采用递归算法而不是批处理算法,大大地提高大地定位精度。在单幅影像处理中,可以重新对卫星的轨道参数与姿态参数进行估值,从而提高影像的大地定位精度。在一条轨道上连续的多幅影像中,可以预报下一幅影像的大地位置,从而对那些不具有地面控制点的影像的大地校正中,实现外推计算。文中介绍并推导了卡尔曼滤波器方程中的转移矩阵和测量矩阵的系数,并推荐用数值回归的办法求得其数值解。文中最后介绍模拟试验及算法计算结果,并讨论其优缺点。