遥感技术的线状地物宽度估算方法

以华北某省的小麦产区为例,通过像元数来确定主要线状地物的解译标准,将地物按照像元数解译成面状和线状,同时建立线状解译的置信区间,实现不同情况下线状地物的面积统计。     

新型圆筒型FPSO垂荡抑制结构优化设计

针对传统圆筒型FPSO垂荡运动剧烈的特点,提出一种带有垂荡抑制结构的圆筒型FPSO。采用1∶77.8的缩尺比制作模型,进行垂荡纵摇衰减试验,得到带有不同垂荡抑制结构模型的固有周期和无因次阻尼系数,进而选取最优的垂荡抑制结构型式。之后计算并对比传统圆筒型FPSO和新型圆筒型FPSO垂荡纵摇运动的固有周期和幅频响应函数。在此基础上,结合我国南海海洋环境条件,设计新型圆筒型FPSO的系泊系统,计算分析自存工况下的耦合动力响应,并与传统圆筒型FPSO进行对比。结果表明,文中提出的垂荡抑制结构可以有效增大系统垂荡纵摇运动的固有周期,改善运动性能,提高系泊的安全性。     

Life cycle of intraseasonal oscillation of summer SST in the western South China Sea

Intraseasonal oscillation (ISO, times-cales of 30~90 d) of summer sea surface temperature (SST) in the western South China Sea is studied using harmonic and empirical orthogonal function analyses of microwave observations by the tropical rainfall measuring mission satellite. Each summer from May to September, two or three ISO events occur off South Vietnam, with a typical period of approximately 50 d. The life cycle of these events from the initiation to decay of SST anomalies is described.     

带有周期分量的多层递阶预报模型

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。     

��GPS����InSAR�����ӳ������о�

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

Crystallisation of sodium sulfate: supersaturation and metastable phases

Crystallisation of sodium sulfate solutions by evaporation under controlled climatic conditions has revealed the existence of crystalline hydrated sodium sulfate salts not previously reported. The sodium sulfate phase crystallising and the concentration of the solution at the point of crystallisation depends on the climatic conditions (temperature and evaporation rate). During the rehydration of the anhydrous sodium sulfate phase, thenardite, another previously unreported phase was formed prior to the nucleation of the stable phase, mirabilite Na₂SO₄ · 10H₂O. The addition of organic inhibitors changes both the crystallisation and the rehydration behavior in this system.     

Structural evidence for large-scale top-to-the-north normal displacement along the Median Tectonic Line in southwest Japan

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.     

Hazard rate estimation of a mixture model with censored lifetimes

This paper is intended to compare the hazard rate from the Bayesian approach with the hazard rate from the maximum likelihood estimate (MLE) method. The MLE of a parameter is appropriate as long as there are sufficient data. For various reasons, however, sufficient data may not be available, which may make the result of the MLE method unreliable. In order to resolve the problem, it is necessary to rely on judgment about unknown parameters. This is done by adopting the Bayesian approach. The hazard rate of a mixture model can be inferred from a method called Bayesian estimation. For eliciting a prior distribution which can be used in deriving a Bayesian estimate, a computerized-simulation method is introduced. Finally, a numerical example is given to illustrate the potential benefits of the Bayesian approach.     

危险率函数在地表破裂型地震危险性评估中的应用—以宁夏灵武断裂为例

在对中国北部板内地区的古地震资料拟合、给出时间相依的统计模型基础上,利用近期获取的灵武断裂有关资料和危险率函数,对灵武断裂未来一定时段的发震潜势和当前地震危险性特征进行了分析,认为该断裂已进入发震时段,在未来10－100年内有发生7．0－7．5级左右地震的潜势。