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261.
在Version 2的基础上,对短波辐射方案进行进一步的改进:引入了新增非灰体气体吸收效应、冰晶粒子形状效应和尺度效应以及云的不均匀性效应(称为Version 3)。数值模拟试验结果表明:Version 3能更好地模拟出全球冬、夏季的降水场、海平面气压场及地表气温场的主要分布特征,并且能相当准确地反映出这几个场的季节性变化特征。Version 3对这3个场的模拟能力明显优于原版本(Version 1)。此外,它对东亚地区的季风降雨具有很好的模拟能力,能较好地反映东亚区域降水的季节性变化。可见,Version 3为进一步研究云-辐射相互作用提供了很好的模式基础。本工作还清楚地表明,模式的进一步发展必须进行对相关物理过程中各个因子的更精确刻画,只有这样,模式才能得到更好的模拟能力。 相似文献
262.
263.
A method for parametric system identification of classically damped linear system in frequency domain is adopted and extended for non‐classically damped linear systems subjected up to six components of earthquake ground motions. This method is able to work in multi‐input/multi‐output (MIMO) case. The response of a two‐degree‐of‐freedom model with non‐classical damping, excited by one‐component earthquake ground motion, is simulated and used to verify the proposed system identification method in the single‐input/multi‐output case. Also, the records of a 10 storey real building during the Northridge earthquake is used to verify the proposed system identification method in the MIMO case. In this case, at first, a single‐input/multi‐output assumption is considered for the system and modal parameters are identified, then other components of earthquake ground motions are added, respectively, and the modal parameters are identified again. This procedure is repeated until all four components of earthquake ground motions which are measured at the base level of the building are included in the identification process. The results of identification of real building show that consideration of non‐classical damping and inclusion of the multi‐components effect of earthquake ground motions can improve the least‐squares match between the finite Fourier transforms of recorded and calculated acceleration responses. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
264.
D. R. Pattanaik 《Pure and Applied Geophysics》2007,164(8-9):1527-1545
The present study is an attempt to examine the variability of convective activity over the north Indian Ocean (Bay of Bengal
and Arabian Sea) on interannual and longer time scale and its association with the rainfall activity over the four different
homogeneous regions of India (viz., northeast India, northwest India, central India and south peninsular India) during the
monsoon season from June to September (JJAS) for the 26 year period (1979 to 2004). The monthly mean Outgoing Long-wave Radiation
(OLR) data obtained from National Oceanic and Atmospheric Administration (NOAA) polar orbiting spacecraft are used in this
study and the 26-year period has been divided into two periods of 13 years each with period-i from 1979 to 1991 and period
-ii from 1992 to 2004. It is ascertained that the convective activity increases over the Arabian Sea and the Bay of Bengal
in the recent period (period -ii; 1992 to 2004) compared to that of the former period (period -i; 1979 to 1991) during JJAS
and is associated with a significantly increasing trend (at 95% level) of convective activity over the north Bay of Bengal
(NBAY). On a monthly scale, July and August also show increase in convective activity over the Arabian Sea and the Bay of
Bengal during the recent period and this is associated with slight changes in the monsoon activity cycle over India. The increase
in convective activity particularly over the Arabian Sea during the recent period of June is basically associated with about
three days early onset of the monsoon over Delhi and relatively faster progress of the monsoon northward from the southern
tip of India. Over the homogeneous regions of India the correlation coefficient (CC) of OLR anomalies over the south Arabian
Sea (SARA) is highly significant with the rainfall over central India, south peninsular India and northwest India, and for
the north Arabian Sea (NARA), it is significant with northwest India rainfall and south peninsular rainfall. Similarly, the
OLR anomalies over the south Bay of Bengal (SBAY) have significant CC with northwest India and south peninsular rainfall,
whereas the most active convective region of the NBAY is not significantly correlated with rainfall over India. It is also
found that the region over northeastern parts of India and its surroundings has a negative correlation with the OLR anomalies
over the NARA and is associated with an anomalous sinking (rising) motion over the northeastern parts of India during the
years of increase (decrease) of convective activity over the NARA. 相似文献
265.
GIS中地籍宗地面积的方差分量估计 总被引:2,自引:0,他引:2
探讨在地籍宗地数字化的面积处理问题中,把已知面积数据和数字化坐标同时作为观测值的面积处理方法.采用方差分量估计,解决已知面积数据参与平差时的权的确定.通过实例分析,认为采用条件平差方差分量估计方法来对宗地面积处理,能够更加合理地调整已有面积与由数字化坐标得到的面积值之间的差异. 相似文献
266.
Helmert方差分量估计的粗差检验与抗差解 总被引:9,自引:0,他引:9
当观测值中含有粗差时,检验表明Helmert方差分量估计结果同样含有粗差,且粗差还可能会发生转移,为有效地抵制粗差和随机模型差的互相影响,指出了发生这一转移的原因,介绍了基于双因子等价权的抗差估计,并针对相关Helmert方差分量估计抗差解求解过程中容易出现的法矩阵0值溢出问题,提出了改进方法。 相似文献
267.
ASP应用中COM组件开发方法研究 总被引:2,自引:0,他引:2
从ASP技术与COM技术出发,针对MCU远程控制应用的多层分布体系结构特点及应用要求,详细论述了如何进行组件线程类型选择、接口设计、物理定位开发与实现具有特定功能的COM组件并如何在ASP应用中创建和扫行,以实现远程控制MCU功能。论述了在设计与实现COM组件过程中,其安全性与作用域的选择。 相似文献
268.
提出了回归分析前作变量变换的依据,并认为变量的概率分布相同时可不作变量变换;应用江苏省土壤中镭和钍的数据建立的数学模型,对该省污染预测、重复调查本底具有现实意义。 相似文献
269.
若干交代成岩成矿作用组份质量转移的计算与分析 总被引:1,自引:0,他引:1
本以几种常见的交代成岩成矿作用为例,介绍了一种新的综合性的组份质量转移计算法-真恒量定值非固定同体积质量计算法(TCFM法),并根据计算结果对这些成岩,成岩作用的形成条件进行了分析。 相似文献
270.