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Employing the mesoscale WRF (Weather Research and Forecast) model, Super Typhoon
Saomai (2006) is simulated. The variation of track and intensity and its offshore rapid
intensification process are well demonstrated by the model, and the temperature and humidity
patterns associated with the dry cold air activity and their impact on and mechanism of the
offshore rapid intensification of Saomai are mainly studied in this paper. The results
indicate that high-resolution water vapor imagery can visually reveal the development,
evolution, interaction as well as the mutual complementation of the dry cold air activity
accompanied with the development of Saomai. The offshore rapid intensification phenomenon of
Saomai is closely related to the dry cold air which originates from the upper- and mid-
troposphere. Besides, the dry cold air from the upper troposphere is stronger than that from
the mid-troposphere. Saomai intensifies as the dry cold air from the northwest moves toward
its circulation but weakens when the dry cold air from the southwest is drawn into the storm.
Dry cold airflows and their cold advection effect caused by the downward motion across the
isentropic surface are favorable to the development of Saomai. The dry cold air always moves
along an isentropic surface from the upper troposphere to the mid-troposphere around the
typhoon circulation and contributes to Saomai’s abrupt intensity change. 相似文献
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近年来冻结施工方法越来越多地使用在城市土木工程施工中,但由于受冻土冻结理论基础的缺失和研究方法的局限,长时间以来人们对冻结法的设计始终没有找到较为理想的方案,参数变量选取遇到很大困难,同时在施工阶段没有较为标准统一的技术规范参照,使得该工法的实际应用往往出现工程量浪费、施工混乱和工程质量无保障等情况,而其中冷冻管直径是主要影响参数。通过同轴管土体冻结试验的研究,采用不同直径的冷冻管进行冻结试验,利用Fluent模型分析冻结过程的温度场分布规律,确定了最优冷冻管管径的选择方法,为冻结法的设计及施工提供依据。 相似文献
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论文针对地质勘探取心工况复杂、钻进深度大、事故发生率高、岩性复杂、钻进参数难以获取、无法实时掌握钻进状态的难题,在充分调研现有工况识别技术的采集原理、功能种类、现场实测的基础上,结合钻探智能化、自动化的发展方向,运用硬件与软件结合的思想,设计了实时测量钻探参数的方案。论文首次提出使用DBSCAN(针对噪声空间基于分布密度进行聚类的算法)密度聚类法分析钻进参数,结合光电编码器增量的正负性进行工况判别,以获取钻头位置以及钻孔深度。该方案可以判别钻进状态,获取钻进工艺参数,将测量数据作为所钻地层的可钻参数来反演地层。钻机的自动化、智能化研究能获取大量地层资料,有利于推进钻进工艺学发展,实现从经验钻探到智能钻探进的突破。同时,为智能钻进系统奠定基础。 相似文献
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