粮食作物产量估算方法研究   总被引：3，自引：0，他引：3  

王建林  太华杰 《气象》1996,22(12):6-9

文章分析了我国自然植被净第一生产力的分布状况和粮食作物生物量的时空变化，以及自然植被净第一生产力与粮食作物生物量的关系，并在此基础上，提出一种我为粮食作物产量的估算的方法。  相似文献   

病态线性模型及其优良算法综述   总被引：3，自引：0，他引：3  

叶松林 《四川测绘》1996,19(2):61-64

本文扼要讨论了线性模型病态问题，综合论述了目前几种解算方法的思想及优缺点．  相似文献   

330硅质断裂带变形特征及其与铀成矿作用的关系   总被引：1，自引：0，他引：1  

梁良  钟芝筠 《铀矿地质》1985,(5)

本文从应力矿物、岩石组构、古应力估算及构造地球化学等方面对330产铀硅质断裂带的形成环境、发展演化及变形机制作了初步分析,并讨论了它们与铀成矿作用的关系。通过构造岩及石英、云母的微观研究,认为本断裂带经历了韧性—脆性—脆韧性—脆性的交替变换变形过程。韧性变形具有波状消光、变形纹、流动构造、B+S构造岩等显微构造和组构特征。据重结晶晶粒粒径测定,其差异应力平均值为0.5干巴。脆性变形与韧性变形明显不同,表现出破裂构造和角砾岩类发育,可见吕对尔线和石英沙钟构造以及S构造岩或均质组构等特点。早期韧性变形阶段形成的糜棱岩是一种富硅岩石,硅除主要来自后来的热液外,也来自原岩的动力分异和动热变质作用。韧性变形阶段之后接着是脆性变形阶段,岩石产生破裂构造,充填了早期脉体。成矿作用主要发生在形成碎裂糜棱岩的脆韧性变形阶段,此时的含矿断裂带是一个半开放系统,成矿的地质环境是:温度200—300℃,差异应力0.5干巴,区域差应力0.5干巴,深度1—2公里,基本上属低温浅成环境。  相似文献   

A bound for the Euclidean norm of the difference between the best linear unbiased estimator and a linear unbiased estimator     

J. Mäkinen 《Journal of Geodesy》2002,76(6-7):317-322

 A bound is established for the Euclidean norm of the difference between the best linear unbiased estimator and any linear unbiased estimator in the general linear model. The bound involves the spectral norm of the difference between the dispersion matrices of the two estimators, and the residual sum of squares, all evaluated at the assumed model, but is independent of the provenance of the observation vector at hand. The bound, a straightforward consequence of first principles in Gauss–Markov theory, generalizes previous results on the difference between the best linear unbiased estimator and the ordinary least-squares estimator. In a numerical example from repeated precise levelling, the bound is used to analyse the sensitivity of estimates of vertical motion to the choice of estimator. Received: 9 September 1999 / Accepted: 15 March 2002  相似文献   

水准标志沉降的分析计算     

葛彦增  朱晓红  尚贵佳  李玉敏  刘锡纯 《东北地震研究》2002,18(1):31-39

地面荷载的变化，引起了垂直附加应力的变化，通过弹性理论中应变应力的关系，确定了水准标志沉降量的积分表达式，并用梯形法近似地求出。同时，进行了误差估计。  相似文献   

Linear combinations of order statistics to estimate the position and scale parameters of the Generalized Pareto distribution     

G. Sazlvadori 《Stochastic Environmental Research and Risk Assessment (SERRA)》2002,16(1):1-17

 Ad hoc techniques for estimating the position and the scale parameters of the Generalized Pareto distribution are introduced. The estimators proposed are simple linear combinations of the order statistics: they provide valuable estimates of the parameters of interest, both when the shape parameter is known and when it is unknown (this latter case being of great relevance in practical applications), and show a good performance as well when the sample size is small. The procedures are tested on simulated data, and comparisons with other techniques are shown.  相似文献   

基于Helmert方差分量估计的Vondrak滤波方法     

钟汉青  曾凡河  周晓卫  丁建勋 《测绘工程》2008,17(3):31-33

从基于Helmert方差分量估计的Vondrak滤波方法（简称HVF法）的基本假设入手,介绍HVF方法,该方法能够在未知拟合函数的情况下,通过自动选择合理的平滑因子控制数据平滑的程度,对时序数据序列进行合理平滑,最大限度地削弱数据序列中的随机误差,将信号与噪声合理分离。  相似文献   

带有周期分量的多层递阶预报模型     

李邦宪 《成都信息工程学院学报》1989,(2)

本文针对经典多层递阶方法所存在的缺陷,提出了一种改进方案—带有周期分量的多层递阶预报模型,它利用时间序列的显著周期分量取代原模型中的自回归部分,使之既考虑到各种物理因子的主导作用,又较好地反映了气象要素自身的周期性变化规律,因而预报效果较为稳定。  相似文献   

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罗海滨  何秀凤 《大地测量与地球动力学》2007,27(3):35-38

?????????InSAR???????????????????????????GPS????InSAR????????????????????????InSAR???????????Ч???????????SAR???????????????????????????????GPS?????????????м???????????????????巨??IDW????GPS????????????????д???????????????????????????????????????費?????????????????????IIDW????巨????????????????????????????巨?????????????????????????巨????????????????????????????????????????????????巨Ч?????á?  相似文献   

Structural evidence for large-scale top-to-the-north normal displacement along the Median Tectonic Line in southwest Japan   总被引：1，自引：1，他引：1  

Tetsuzo  Fukunari  Simon R.  Wallis 《Island Arc》2007,16(2):243-261

Abstract   The Median Tectonic Line (MTL) is a first-order tectonic boundary that separates the Sanbagawa and Ryoke Metamorphic Belts. Strike-slip movements on the MTL have been well documented by many workers. New field based structural studies in the Sanbagawa Belt close to the MTL reveal a large number of secondary faults and semibrittle shear bands indicating a top-to-the-north normal sense of displacement. The strikes of these shear zones and their spatial distributions suggest that development of these structures is related to movements on the MTL. These results imply that the MTL has a large-scale normal shear component on a regional scale that can help account for the exhumation of the Sanbagawa Belt. Our proposed history of the MTL can also account for changes in the geometry of folds in the Sanbagawa Belt.  相似文献