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压能场在暴雨分析中的应用 被引量:3
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作者 陈忠明 《应用气象学报》 CSCD 北大核心 1993年第4期498-503,共6页
利用简化散度方程将压能场分布的非均匀性与散度场演化联系起来,初步揭示了暴雨和雨带活动与压能密集带相联系的物理机制.并可通过计算压能场的分布来诊断暴雨落区.
关键词 散度演化 压能场 暴雨 降水
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压能场与台风移行
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作者 章永伟 刘小根 +1 位作者 周钦华 张学圣 《杭州大学学报(自然科学版)》 CSCD 1993年第3期357-362,共6页
本文探讨了压能场与台风移行的关系,提出了一个台风移行公式,分析了它的物理意义,并对四个台风个例进行了计算.计算结果表明与实况相当一致.此公式可供气象台站台风路径预报业务使用.
关键词 台风 压能场 预报
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一次特大暴雨过程的压能场、湿焓场分析 被引量:3
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作者 徐大红 《贵州气象》 1996年第1期32-34,共3页
本文采用1995年6月30日,7月1日08时850、700、500hPa高度场及风场资料,分析了逐日逐层的压能场、湿焓场特征,指出等压能线与等湿焓线密集带与暴雨过程和落区有较好的对应关系。
关键词 暴雨 湿焓平流 压能场
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压能场在暴雨预报中的应用 被引量:1
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作者 方庆文 《贵州气象》 1994年第4期37-38,共2页
利用1993年7月逐日08时850hPa高度场及风场资料,分析了该月压能场特征,得出等压能线密集带与我区暴雨有良好的对应关系。在分析的基础上初步总结出用压能场预报我区暴雨的指标,并进行历史回报,效果较好。
关键词 降水 暴雨预报 压能场
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压能场在低纬天气分析和预报中的应用(二)
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作者 阮均石 《贵州气象》 1990年第6期30-35,共6页
关键词 压能场 低纬 天气预报
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压能、湿焓场与暴雨落区的诊断分析 被引量:8
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作者 黄仪方 琚建华 《高原气象》 CSCD 北大核心 2002年第2期154-158,共5页
通过分析压能场与湿焓场的分布特征, 讨论了它们对暴雨发生可能产生的影响。这种影响实质上是由于动力学与热力学的相互作用所造成的。在本文分析的暴雨个例中, 暴雨过程都与等压能线密集带和等湿焓线密集带有一定联系, 在暴雨发... 通过分析压能场与湿焓场的分布特征, 讨论了它们对暴雨发生可能产生的影响。这种影响实质上是由于动力学与热力学的相互作用所造成的。在本文分析的暴雨个例中, 暴雨过程都与等压能线密集带和等湿焓线密集带有一定联系, 在暴雨发生前24 h一般有强的正湿焓平流, 暴雨主要落区一般出现在平流最强的地方。因此, 分析压能场与湿焓场可以获取一些新的信息, 这对提高暴雨的预报能力可以起到一定的作用。 展开更多
关键词 动力学 热力学 压能场 湿焓 暴雨落区 诊断分析
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山西省暴雨落点落区预报业务系统研究
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作者 苗爱梅 李馗峰 +2 位作者 贾利冬 袁怀亭 任璞 《山西气象》 2001年第4期2-5,共4页
在用“聚类分析”、“加权压能场和湿斜压”以及“灰色预测”等方法制作山西省汛期暴雨落点落区预报时,同时用“湿辐合”方法进行计算,并采用“湿辐合”与“聚类分析”暴雨落点落区叠合集成,“湿辐合”与“加权压能场湿斜压”暴雨落点... 在用“聚类分析”、“加权压能场和湿斜压”以及“灰色预测”等方法制作山西省汛期暴雨落点落区预报时,同时用“湿辐合”方法进行计算,并采用“湿辐合”与“聚类分析”暴雨落点落区叠合集成,“湿辐合”与“加权压能场湿斜压”暴雨落点落区叠合集成,以及“湿辐合”与“灰色预测”等方法叠合集成,客观地确定出预报量可能出现的落点或落区。经过历史资料回代运算和2001年实时运行表明,此方法预报效果良好。 展开更多
关键词 聚类分析 湿辐合 加权压能场 湿斜 灰色预测 暴雨落点落区预报业务系统 降水预报
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Effects of hydrostatic pressure and external electric field on the impurity binding energy in strained GaN/Al_xGa_(1-x)N spherical quantum dots 被引量:2
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作者 达来木仁 闫祖威 石磊 《Optoelectronics Letters》 EI 2012年第3期224-228,共5页
The binding energy and Stark effect energy shifts of a shallow donor impurity state in a strained GaN/AlxGa1-xN spherical finite-potential quantum dot (QD) are calculated using a variational method based on the effect... The binding energy and Stark effect energy shifts of a shallow donor impurity state in a strained GaN/AlxGa1-xN spherical finite-potential quantum dot (QD) are calculated using a variational method based on the effective mass approximation. The binding energy is computed as a function of dot size and hydrostatic pressure. The numerical results show that the binding energy of the impurity state increases, attains a maximum value, and then decreases as the QD radius increases for any electric field. Moreover, the binding energy increases with the pressure for any size of dot. The Stark shift of the impurity energy for large dot size is much larger than that for the small dot size, and it is enhanced by the increase of electric field. We compare the binding energy of impurity state with and without strain effects, and the results show that the strain effects enhance the impurity binding energy considerably, especially for the small QD size. We also take the dielectric mismatch into account in our work. 展开更多
关键词 Binding energy Electric fields GALLIUM Hydrostatic pressure Semiconductor quantum dots
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Unsteady Behavior of Surge and Rotating Stall in an Axial Flow Compressor 被引量:3
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作者 Yutaka OHTA Yutaka FUJITA Daisuke MORITA 《Journal of Thermal Science》 SCIE EI CAS CSCD 2012年第4期302-310,共9页
Unsteady behaviors as well as unsteady cascade flow fields of a single-stage axial flow compressor were experi- mentally investigated by detail measurements of unsteady performance characteristics and casing wall pres... Unsteady behaviors as well as unsteady cascade flow fields of a single-stage axial flow compressor were experi- mentally investigated by detail measurements of unsteady performance characteristics and casing wall pressure and internal flow velocity fluctuations. The main feature of the test compressor is a capacity tank connected di- rectly to the compressor outlet in series through slits and a concentric duplex pipe, and also jet nozzles in order to inject compressed air toward the rotor tip region. Research attention is focused on the post-stall characteristics of surge and rotating stall which occur simultaneously. When the compressor was connected to the capacity tank, surge was generated with rotating stall in accordance with the capacitance increment of whole compressor system The surge behavior changed irregularly with throttling valve installed behind the compressor, and several types of surge cycles were observed. In addition, the surge cycle changed by jet injection to the rotor tip region. The re- suits suggested that the blockages of the cascade flow which were generated by a stall cell play an important role in deciding the surge behaviors. 展开更多
关键词 Axial flow compressor SURGE Rotating stall Stall cell Jet injection
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Effects of Measuring Positions on the Measured Aerodynamic Performance of a Centrifugal Compressor 被引量:1
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作者 Hongwei MA Jun ZHANG 《Journal of Thermal Science》 SCIE EI CAS CSCD 2010年第2期110-114,共5页
This paper performs a numerical simulation of three-dimensional flow field in a centrifugal compressor with long inlet and outlet pipes using CFX software.By arranging virtual probes at different positions in both inl... This paper performs a numerical simulation of three-dimensional flow field in a centrifugal compressor with long inlet and outlet pipes using CFX software.By arranging virtual probes at different positions in both inlet and outlet planes,the aerodynamic performance of the centrifugal compressor is measured and compared with each other.Then effects of measuring positions on measurement results are discussed.The results show that it will generate notable measuring errors of the pressure ratio and efficiency if the inlet total pressure is measured using a single-point probe.The inlet total pressure data can be accurate when they are measured using a 3-point rake.The outlet total pressure and total temperature data can not be accurate if they are respectively measured at one circumferential position even using a multi-point rake.Increasing tangential measuring positions at the outlet is effective to improve the test accuracy.When the outlet total pressure and total temperature are respectively measured at 3 tangential positions,the data can be almost accurate. 展开更多
关键词 centrifugal compressor aerodynamics performance measuring error measurement position probe.
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