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Wavelet analysis of spring climate characteristics in arid aeolian area of agro-pastoral ecotone in China 被引量:2
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作者 Chun-xia ZOU Xiang-dong SHEN +2 位作者 Hong-yun LI Xia-zi LI Zhang-jun LI 《Water Science and Engineering》 EI CAS 2012年第3期269-277,共9页
The unique regional climate characteristics are among the main reasons for the frequent wind-sand activity in arid and cold areas in the agro-pastoral ecotone in Inner Mongolia, China. This paper focuses on the time s... The unique regional climate characteristics are among the main reasons for the frequent wind-sand activity in arid and cold areas in the agro-pastoral ecotone in Inner Mongolia, China. This paper focuses on the time series of temperature and precipitation in spring when sandstorms often occur in the area. Based on meteorological data for a 46-year period from 1959 to 2004, multi-scale variations and abrupt changes in temperature and precipitation were analyzed with the Mexican hat function (MHF) wavelet method, showing the multi-scale variation characteristics of temperature and precipitation, as well as the periods and change points at different time scales. The relationship between temperature and precipitation was obtained using the wavelet analysis method. Obvious staggered features of the variations of spring temperature and precipitation were observed in this agro-pastoral ecotone. The strongest oscillation periods of spring temperature variations were 1 and 22 years, while for precipitation, the strongest oscillation periods of variations were 2, 8, and 22 years. In addition, lower spring temperature corresponded to lower precipitation, whereas higher temperature yielded higher precipitation rate. 展开更多
关键词 spring temperature spring precipitation climate characteristics MHF waveletmethod arid aeolian area agro-pastoral ecotone
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用拟小波方法研究纵向共振对梁动力失稳的影响
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作者 宋志伟 李威 渠鸿飞 《噪声与振动控制》 CSCD 2012年第3期67-71,共5页
提出求解梁动力响应的拟小波方法,用该方法研究纵向共振对梁动力稳定性的影响,同时考虑阻尼的作用。研究表明纵向共振导致严重的动力失稳,而阻尼有效提高其稳定性。这些结论与现有结论吻合得很好。从而验证采用拟小波方法研究此问题的... 提出求解梁动力响应的拟小波方法,用该方法研究纵向共振对梁动力稳定性的影响,同时考虑阻尼的作用。研究表明纵向共振导致严重的动力失稳,而阻尼有效提高其稳定性。这些结论与现有结论吻合得很好。从而验证采用拟小波方法研究此问题的可行性和有效性。 展开更多
关键词 振动与波 动力稳定性 参数共振 纵向共振 拟小波方法
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