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Trends of Extreme Flood Events in the Pearl River Basin during 1951-2010

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Advances in Climate Change research 2013年第2期4卷 110-116页

作者： WU Zhi-Yong LU Gui-Hua LIU Zhi-Yu WANG Jin-Xing XIAO Heng Institute of Water Problems Hohai University National Engineering research Center of Water Resources Effcient Utilization and Engineering Safety HohaiUniversity Water Resources Information Center of the Ministry of Water Resources

The study investigated the trend of extreme flood events in the Pearl River basin during 1951-2010. Stream flow data at 23 gauging stations were used for the study. The Pearson type III distribution was selected for the flood frequency analysis. Results indicate that extreme flood events increase significantly in the Pearl River Basin since 1980. At the 23 gauging stations, there are 16 (70%) stations show positive (increasing) trends in 1981-2010. Most of the 16 stations are located along the West River and North River. While 7 (30%) stations show negative (decreasing) trends, and are found in the East River and the southeast region of the West River Basin.

关键词： flood trend climate change Pearl River Basin

CHARACTERISTICS OF MIDDLE EAST JET STREAM DURING SEASONAL TRANSITION AND ITS RELATION WITH INDIAN SUMMER MONSOON ONSET

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Journal of Tropical Meteorology 2014年第3期20卷 208-217页

作者：倪东鸿孙照渤李忠贤曾刚邓伟涛 Key Laboratory of Meteorological Disaster of Ministry of Education and Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science & Technology

By using the NCEP/NCAR pentad reanalysis data from 1968 to 2009, the variation characteristics of Middle East jet stream(MEJS) and its thermal mechanism during seasonal transition are studied. Results show that the intensity and south-north location of MEJS center exhibit obvious seasonal variation characteristics. When MEJS is strong, it is at 27.5°N from the 67 th pentad to the 24 th pentad the following year; when MEJS is weak, it is at 45°N from the 38 th pentad to the 44 th pentad. The first Empirical Orthogonal Function(EOF) mode of 200-hPa zonal wind field shows that MEJS is mainly over Egypt and Saudi Arabia in winter and over the eastern Black Sea and the eastern Aral Sea in summer. MEJS intensity markedly weakens in summer in comparison with that in winter. The 26th-31 st pentad is the spring-summer transition of MEJS, and the 54th-61 st pentad the autumn-winter transition. During the two seasonal transitions, the temporal variations of the 500-200 hPa south-north temperature difference(SNTD) well match with 200-hPa zonal wind velocity, indicating that the former leads to the latter following the principle of thermal wind. A case analysis shows that there is a close relation between the onset date of Indian summer monsoon and the transition date of MEJS seasonal transition. When the outbreak date of Indian summer monsoon is earlier than normal, MEJS moves northward earlier because the larger SNTD between 500-200 hPa moves northward earlier, with the westerly jet in the lower troposphere over 40°-90°E appearing earlier than normal, and vice versa.

关键词： Middle East jet stream seasonal transition characteristics thermal effect onset date of Indiansummer monsoon

Enhancement of Innovation Competence of College Students Majoring in Mathematics Education through Curriculum Optimization

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Journal of Contemporary Educational research 2024年第10期8卷 83-89页

作者： Chengqiang Wang Qiuxia Wu Xiangqing Zhao Zhiwei Lv School of Mathematics and Physics Suqian UniversitySuqian 223800Jiangsu ProvinceChina

The innovation competence of K-12 education teachers undoubtedly plays a crucial role in fostering the innovation abilities of their students.K-12 mathematics education equips students with the critical thinking and problem-solving skills essential for their future studies in colleges and universities,helping them grasp complex techniques to address challenges in everyday life and their ***,it is of great significance to study strategies for improving the innovation competence of college students majoring in Mathematics Education,as they will likely become K-12 education mathematics teachers directly after graduating from colleges or *** this paper,we study strategies for enhancing the innovation competence of college students majoring in Mathematics Education through curriculum *** analyze and explain in detail the importance of innovation competence for college students majoring in Mathematics Education and the difficulties encountered in enhancing college students’innovation *** the help of the analysis of the importance and challenges of enhancing college students’innovation competence,we propose several strategies to improve the innovation competence of college students majoring in Mathematics Education based on curriculum *** findings presented in this paper can be applied to develop strategies for college students majoring in Physics and Chemistry Education.

关键词： K-12 education Innovation competence College students Mathematics Education Curriculum optimization

Examination of Microphysical Relationships and Corresponding Microphysical Processes in Warm Fogs

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Acta meteorologica Sinica 2013年第6期27卷 832-848页

作者：陆青松刘延刚牛生杰赵丽娟于华英程穆宁 Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration Collaborative Innovation Center on Forecast and Evaluation of Meteorological DisastersNanjing University of Information Science and Technology State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences Atmospheric Sciences Division Brookhaven National Laboratory Xiamen Environmental Monitoring Central Station Second Institute of Environmental Assessment Jiangsu Provincial Academy of Environmental Science

In this paper, the microphysical relationships of 8 dense fog events collected from a comprehensive fog observation campaign carried out at Pancheng（32.2 N, 118.7 E） in the Nanjing area, China in the winter of 2007 are investigated. Positive correlations are found among key microphysical properties（cloud droplet number concentration, droplet size, spectral standard deviation, and liquid water content） in each case, suggesting that the dominant processes in these fog events are likely droplet nucleation with subsequent condensational growth and/or droplet deactivation via complete evaporation of some droplets. The abrupt broadening of the fog droplet spectra indicates the occurrence of the collision-coalescence processes as well, although not dominating. The combined efects of the dominant processes and collision-coalescence on microphysical relationships are further analyzed by dividing the dataset according to visibility or autoconversion threshold in each case. The result shows that the specific relationships of number concentration to volume-mean radius and spectral standard deviation depend on the competition between the compensation of small droplets due to nucleation-condensation and the loss of small droplets due to collision-coalescence. Generally, positive correlations are found for diferent visibility or autoconversion threshold ranges in most cases, although negative correlations sometimes appear with lower visibility or larger autoconversion threshold. Therefore, the compensation of small droplets is generally stronger than the loss, which is likely related to the sufcient fog condensation nuclei in this polluted area.

关键词： fog microphysics microphysical relationships physical processes observations