Testing spatial heterogeneity in geographically weighted principal components analysis

We propose a method to evaluate the existence of spatial variability in the covariance structure in a geographically weighted principal components analysis (GWPCA). The method, that is extensive to locally weighted principal components analysis, is based on performing a statistical hypothesis test using the eigenvectors of the PCA scores covariance matrix. The application of the method to simulated data shows that it has a greater statistical power than the current statistical test that uses the eigenvalues of the raw data covariance matrix. Finally, the method was applied to a real problem whose objective is to find spatial distribution patterns in a set of soil pollutants. The results show the utility of GWPCA versus PCA.     

最佳地电台台址条件与环境条件的讨论

地电台观测地电阻率及其变化以研究地震活动规律，首要的问题是如何选择或评估其台址的优劣，选取最佳地电台台址。文中讨论了地电台台址的地质构造条件、测区地下介质结构条件、介质水文条件、地形地貌条件、电磁干扰等对地电台站观测效能的影响，为选建和评估地电台台址提供较全面、系统的依据。     

1945—1995年国际参考地磁场

本文回顾了国际参考地磁场(IGRF)的建立和修改过程;介绍了最新的IGRF模型,即第六代国际参考地磁场;综述了国际参考地磁场在地磁学中的应用,并指出了在使用过程中需要注意的一些问题.     

A petroleum discovery-rate forecast revisited—The problem of field growth

A forecast of the future rates of discovery of crude oil and natural gas for the 123,027-km² Miocene/Pliocene trend in the Gulf of Mexico was made in 1980. This forecast was evaluated in 1988 by comparing two sets of data: (1) the actual versus the forecasted number of fields discovered, and (2) the actual versus the forecasted volumes of crude oil and natural gas discovered with the drilling of 1,820 wildcat wells along the trend between January 1, 1977, and December 31, 1985. The forecast specified that this level of drilling would result in the discovery of 217 fields containing 1.78 billion barrels of oil equivalent; however, 238 fields containing 3.57 billion barrels of oil equivalent were actually discovered. This underestimation is attributed to biases introduced by field growth and, to a lesser degree, the artificially low, pre-1970's price of natural gas that prevented many smaller gas fields from being brought into production at the time of their discovery; most of these fields contained less than 50 billion cubic feet of producible natural gas.     

《军官地图集》的设计特色

本文根据作者参与组织指导《军官地图集》设计与生产的体会,从设计思想、结构模式、内容选题、表示方法、整体协调和制印工艺等方面阐述《军官地图集》的设计特色,通过对这一典型作品的剖析,探讨地图集设计与生产的基本规律。     

On the gravitational fields of Pandora and Prometheus

Utilizing topographic models of Saturn's F-ring shepherd satellites Prometheus (S16 1980S27) and Pandora (S15 1980S26), derived by Stooke (1994), and supposing that their mass density is constant, we derived basic geometrical and dynamical characteristics of the moons. They include the volume and mass, the mean radii, the tensor of inertia, and Stokes coefficients of the harmonic expansions of external gravitational potential. The best fitting ellipsoid approximations of the topography were calculated. A simple method of determining the gravitational potential on the surface of an irregular satellite is presented. Examples of equipotential surfaces of the satellites are shown     

近岸水质遥感评价参数的选择及评价模型的研究

利用遥感技术的水质评价是海洋环境监测的必然趋势,但目前可通过遥感技术反演的水质参数种类远少于《海水水质标准》中的35项,因此遥感监测时必须反演的水质参数有哪些?利用有限的参数该建立怎样的水质评价模型?成为我们关心的问题。本文以雷州半岛海域为研究对象,通过对实测数据的分析得出13种水质参数中的主导参数为总氮(N)、总磷(P)、化学需氧量(COD)、酸度(pH)、溶解氧(DO)这5种;再通过数理统计理论得出这5种参数对水质分类判别能力的大小关系为:COD> DO> P> N> pH,分别建立对应的五参数、四参数、三参数水质评价模型,并确定最优评价模型。即,雷州半岛海域水质遥感评价时必须反演的参数为COD、DO、P和N,水质综合评价模型为四参数模型,为后续其他海域水质的遥感监测提供可借鉴的方法。     

半滑舌鳎(Cynoglossus semilaevis)幼鱼生长性状和底色的表型和遗传参数估计

半滑舌鳎是重要的经济鱼类,已经被广泛推广养殖,致力于养殖方面的研究开展了很多工作,但是对半滑舌鳎生长性状进行准确遗传评估的研究还未见报道。为了对生长性状进行准确的遗传参数估计,本次研究以80个半滑舌鳎家系为研究对象,对半滑舌鳎早期生长性状（包括个体全长、体宽和体质量）进行分析。另外还将鱼体底面纯白与否（命名为底面颜色）作为一个性状进行研究。结果表明,四个性状都属于中等遗传力（全长为0.210、体宽为0.259、体质量为0.268、底面颜色为0.362）。三个生长性状之间具有很高的遗传相关性（0.913-0.959）,表明如果三个性状进行间接选择的话,将会取得较好效果。底面颜色性状与三个生长性状均为正遗传相关,相关系数在0.241-0.353之间,由此可知,对底面颜色进行选择时,可以加强生长性状的选择效果。通过家系育种值排序,初步筛选出了生长性状优良遗传背景丰富的16个全同胞家系,将作为亲鱼繁殖后代。本研究为半滑舌鳎优良品种的成功培育提供了重要基础资料。     

地质要素在工程构筑选址中的影响特性分析

新的作战样式催生地质环境下工程构筑选址这一全新的命题。本文探究了地质要素对工程构筑选址的影响,将工程分成三大类,总结三类工程的地质影响要素;通过分析土体、岩体的物理化学和力学性质对工事的作用,总结陆域水体对岩体和建筑材料的物理化学作用,梳理主要的构造、地质灾害和资源类型对工程的影响,明确了六大类地质要素在工程构筑选址中的影响特性,为下一步确定各要素在工程构筑选址中的权重以及构建工程构筑选址信息模型奠定了基础。     

A New Infrared Atmospheric Sounding Interferometer Channel Selection and Assessment of Its Impact on Met Office NWP Forecasts

A new set of Infrared Atmospheric Sounding Interferometer(IASI) channels was re-selected from 314 EUMETSAT channels.In selecting channels,we calculated the impact of the individually added channel on the improvement in the analysis outputs from a one-dimensional variational analysis(1D-Var) for the Unified Model(UM) data assimilation system at the Met Office,using the channel score index(CSI) as a figure of merit.Then,200 channels were selected in order by counting each individual channel's CSI contribution.Compared with the operationally used 183 channels for the UM at the Met Office,the new set shares 149 channels,while the other 51 channels are new.Also examined is the selection from the entropy reduction method with the same 1D-Var approach.Results suggest that channel selection can be made in a more objective fashion using the proposed CSI method.This is because the most important channels can be selected across the whole IASI observation spectrum.In the experimental trial runs using the UM global assimilation system,the new channels had an overall neutral impact in terms of improvement in forecasts,as compared with results from the operational channels.However,upper-tropospheric moist biases shown in the control run with operational channels were significantly reduced in the experimental trial with the newly selected channels.The reduction of moist biases was mainly due to the additional water vapor channels,which are sensitive to the upper-tropospheric water vapor.