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排序方式: 共有217条查询结果,搜索用时 15 毫秒
181.
Oluwagbemiga O. Jegede 《Boundary-Layer Meteorology》1997,85(1):161-173
A simple and straightforward expression isproposed, which is based on the Fourier seriesdecomposition technique, for estimating hourly averagednet radiation from the corresponding values of airtemperature at a tropical location in West Africa. Thecomparisons made of the estimated net radiation withactual measurements (case studies) clearlydemonstrate that the scheme is efficient, both inclear and under cloudy weather conditions. Theestimates are also shown to be better than thosedetermined from an alternative relationship usingparametrizations for the shortwave and longwave components at the surface. The presentprocedure can easily be implemented in existingmeteorological preprocessors to calculate the sensibleheat flux for the Gaussian-based air pollutionmodels. 相似文献
182.
183.
Igor Tsukrov Oleg Eroshkin David Fredriksson M. Robinson Swift Barbaros Celikkol 《Ocean Engineering》2003,30(2):251-270
A consistent finite element is proposed to model the hydrodynamic response of net panels to environmental loading. This equivalent net element is constructed to reproduce the drag, buoyancy, inertial and elastic forces exerted on the netting by current and waves. To evaluate the accuracy of the proposed finite element modeling, numerical predictions have been compared with the experimental observations and (simplified) analytical results of other authors. This new modeling technique has been applied to evaluate the performance of a tension leg fish cage in the open ocean environment. 相似文献
184.
185.
文献检索是开展一切研究和设计工作的前提和基础,对工作进程起着重要帮助作用。随着IT技术的迅猛发展和日益普及,丰富,快捷的网上全文资源的开发和利用越来越成为人们获取信息资源的重要途径。本文基于中文期刊全文数据库中渤海海相关全文资源,通过系统整理,筛选,分析,归纳出了1994-2001年渤海海冰相关研究领域的发展趋势,为了使科技人员准确有效地获取资料,对网上资源的相关期刊源,科研机构及其科研领域的状况做了归纳介绍,以便各研究机构,领域的交流和资源共享。本文能够对渤海海冰研究相关领域的发展现状有个总体认识,对科技人员的网上可持续资源利用有所帮助和启迪。 相似文献
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187.
W. Kohsiek C. Liebethal T. Foken R. Vogt S. P. Oncley Ch. Bernhofer H. A. R. Debruin 《Boundary-Layer Meteorology》2007,123(1):55-75
An important part of the Energy Balance Experiment (EBEX-2000) was the measurement of the net radiation and its components.
Since the terrain, an irrigated cotton field, could not be considered homogeneous, radiation measurements were made at nine
sites using a variety of radiation instruments, including pyranometers, pyrgeometers and net radiometers. At several of these
sites multiple instruments were employed, which enabled us to compare instruments and assess accuracies. At all sites the
outgoing longwave and shortwave radiation and the net radiation were measured, while the incoming radiation was supposed to
be uniformly distributed over the field and was therefore measured at three sites only. Net radiation was calculated for all
sites from the sum of its four components, and compared with the direct measurement of net radiometers. The main conclusions
were: (a) the outgoing shortwave radiation showed differences of up to 30 W m−2 over the field; the differences were not clearly related to the irrigation events; (b) the outgoing longwave radiation showed
differences of up to 50 W m−2; the differences increased during the periods of irrigation; (c) the net radiation showed differences of several tens of
W m−2 across the field, rising to 50 W m−2 or more during the periods of irrigation; (d) the net radiation is preferably to be inferred from its four components, rather
than measured directly, and (e) attention should be paid to the characteristics of pyranometers that measure the outgoing
radiation, and thus are mounted upside down, while they are commonly calibrated in the upward position. The error in the net
radiation at EBEX-2000 is estimated at max (25 W m−2, 5%) per site during the day and 10 W m−2 at night.
The National Center for Atmospheric Research is supported by the National Science Foundation. 相似文献
188.
利用ERBE资料分的了1985~1988年期间青藏高原地气系统辐射收支的分布特征与几次重大天气气候事件的关系,结果表明,ElNino期间,高原东南部地区(Ⅲ区即90°E以东,35°N以南)加热场强度比高原西部地区(I区即90°E以西)及高原东北部地区(Ⅱ区即90°E以东,35°N以北)要大,LaNina期间,高原I区的热源强度比Ⅱ,Ⅲ区大,高原热源强度大,西南季风弱,反之,西南季风强。 相似文献
189.
内蒙古阿拉善地区的第三系及其动物群 总被引:1,自引:0,他引:1
笔者依据丰富翔实的资料,论述了该区第三地层的分布,区划,地层划分沿革,岩性,岩相古地理特征及地质演化史;在地层方面,首次在内蒙古西部建立了比较完整的第三纪地层序列;命名和划分了中始新统乌兰乌珠尔组,上始新统查干布拉格组。下渐新统乌兰塔塔尔组,上渐新统,下中新统乌尔较组,上中新统呼和好来组和上新统昂冈浩特组等6个地层单元,补充界定了查干布拉格组并将其时代厘定为晚始新世;在动物群方面,发现和命名了中始 相似文献
190.
基于前兆台网中心的MS SQL Server地震前兆数据库,利用交互式动态Web开发技术建立起辽宁省地震前兆数据的网上服务系统,为台站和用户之间建立起便捷的数据服务通道。 相似文献