工程控制网精度设计的多元分析法     

吴栋材 《武汉大学学报(信息科学版)》1992,(3)

本文结合当前工程控制网设计的主元分析法和数学模型扭曲法,提出了根据谱分解的方法进行控制网精度设计的多元分析法。文中介绍了该法的基本原理,并结合实例说明了该法对全面判定控制网的设计质量的有效性。  相似文献   

Linear coregionalization model: Tools for estimation and choice of cross-variogram matrix   总被引：13，自引：0，他引：13  

M. Goulard  M. Voltz 《Mathematical Geology》1992,24(3):269-286

The geostatistical analysis of multivariate data involves choosing and fitting theoretical models to the empirical matrix. This paper considers the specific case of the model of linear coregionalization, and describes an automated procedure for fitting models, that are adequate in the mathematical sense, using a least-squares like technique. It also describes how to decide whether the number of parameters of the cross-variogram matrix model should be reduced to improve stability of fit. The procedure is illustrated with an analysis of the spatial relations among the physical properties of an alluvial soil. The results show the main influence of the scale and the shape of the basic models on the goodness of fit. The choice of the number of basic models appears of secondary importance, though it greatly influences the resulting interpretation of the coregionalization analysis.  相似文献   

Structural investigations of sulphur-rich macromolecular oil fractions and a kerogen by sequential chemical degradation     

H.H. Richnow  A. Jenisch  W. Michaelis 《Organic Geochemistry》1992,19(4-6)

Structural studies of a sulphur-rich kerogen and macromolecular oil fractions from the Monterey Formation were performed by selective sequential chemical degradation. The method provides low-molecular weight compounds as former building blocks of the network which allow detailed analyses on a molecular level. The degradation sequence is based on three subsequently performed reactions—a selective cleavage of sulphur bonds in the first step carried out with Ni(0)cene/LiAlD₄, an ether and ester bond cleavage (BCl₃), and an oxidation of aromatic entities by ruthenium tetroxide as a final step. Each step of this sequence afforded a considerable amount of low-molecular weight material which was separated chromatographically and studied by GC and GC/MS, while the high-molecular weight or insoluble fractions were subjected to the next reaction step.The chemical degradation products—hydrocarbons and carboxylic acids—are discussed in terms of incorporation into the macromolecular structure, distribution of heteroatomic bridges and the genetic relationships between the different macromolecular crude oil fractions and kerogen.Labelling experiments with deuterium provided evidence for a simultaneous linkage by oxygen and sulphur functionalities or by aromatic units and sulphur bonds of cross-linking macromolecular network constituents.The determination of sulphur positions in the macromolecule suggests early diagenetic sulphur incorporation into the biological precursor compounds and subsequent formation of a cross-linked network.  相似文献   

Near-source characterization of the seismic wavefield radiated from quarry blasts     

Sharon K. Reamer  Klaus-G. Hinzen  Brian W. Stump 《Geophysical Journal International》1992,110(3):435-450

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秦岭南坡植被的区系地理成分分析——以湑水流域为例   总被引：11，自引：0，他引：11  

张秦伟 《地理研究》1992,11(2):83-92

本文对秦岭南坡清水流域主要植被类型的区系地理成分进行了分析,结果表明:植物种、属的地理成分具有明显的垂直分异现象。  相似文献   

Chemical composition of saline and subsaline lakes of the northern Great Plains,western Canada   总被引：2，自引：0，他引：2  

William M. Last 《International Journal of Salt Lake Research》1992,1(2):47-76

The northern Great Plains of Canada stretch from the Precambrian Shield near Winnipeg, Manitoba, westward for ∼1,700 km to the Rocky Mountains foothills. This vast region of flat to gently rolling terrain contains a very large number of salt lakes. Major ion chemical data on ∼500 of them are available. Although the average brine (salinity, 37 ppt) is a Na⁺−SO₄ ²⁻ type of water, the lakes exhibit a wide range of salinities and ionic compositions. This diversity is confirmed by Q-mode cluster analysis; it identified thirteen major water chemistry types. Most ions display distinct trends, both spatially and with increasing salinity. All dissolved components increase with increasing salinity, but at different rates. The relative proportions of Ca²⁺ and HCO₃ ⁻+CO₃ ²⁻ ions show a strong decrease with increasing brine salinity, whereas SO₄ ²⁻ ions increase with increasing salinity. The ionic proportions of Na⁺, Mg²⁺, K⁺ and Cl⁻ exhibit no significant relationship with salinity. R-mode factor analysis of the lake water chemistry, combined with selected environmental parameters, identifies groundwater composition, climate, and the elevation of the lake within the drainage system as most important in controlling brine chemistry and salinity on a regional basis. Variability in source of ions, reaction processes and products are undoubtedly key factors in helping to explain brine chemistry of an individual basin or variation from a local perspective, but these factors are generally poorly understood and not quantified on a regional basis. Palliser Triangle Global Change Project Contribution Number 3.  相似文献   

RESPONSES OF SUMMER RAINFALL OVER CHINA TO ANOMALIES OF SEA SURFACE TEMPERATURE IN THE NORTH PACIFIC          下载免费PDF全文

Huang Jiayou 《Acta Meteorologica Sinica》1991,5(1):79-89

The temporal and spatial responses of summer(June—August)rainfall (SR) over China to anomalies of sum-mer sea surface temperature (SST) in the North Pacific is investigated by using regression analysis and prin-cipal component analysis in this paper.The results show that the responses of SR over China to SST anomalyin the eastern North Pacific in middle latitudes are more sensitive than the others.The strong response areasof SR to SST are generally located in the Changjiang River valley,west:rn North of China,and South China.The spatial pattern of responses of SR to SST manifests in the spatial pattern of the first principal componentnamely,the domain shape with negative-positive-negative anomalies along south-north direction,thus the signof anomalies in the Changjiang River valley is contrary to that of its North or South.  相似文献   

重庆地区降水对气溶胶浓度及雨水中离子浓度的影响   总被引：1，自引：0，他引：1  

吴玉霞  沈志来 《高原气象》1991,10(1):52-60

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成都平原东部地震动小区划研究     

曾勇 《四川地震》1991,(4):1-8

场地的区域工程地质条件决定了场地土结构及土动力学参数的区域性差异,对强震地面运动起着重要的控制作用。为了考虑这种控制作用,以便合理地进行成都平原地震动小区划,本文根据一定数量的地震反应分析结果和所处的区域工程地质条件,建立了地貌单元、土层厚度和土层结构等因素与各类地震反应谱和各档峰值加速度的统计直方图。并引入分量分析方法,对原始因素进行正交变换,用产生互不相关的新因素来代替它们。正交变换之后,根据因子得分矩阵建立模糊关系矩阵 R,根据反映新因素重要程度的因子载荷矩阵生成新因素权重矩阵 A,然后采用模糊综合评判方法,判别成都平原东部各点的地面地震动类型,并由判别结果勾划了本区地震动小区划图。  相似文献   

在裂变径迹测定年代中准确测定中子通量   总被引：1，自引：0，他引：1  

赵云龙  翟鹏济 《铀矿地质》1991,7(2):113-118

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