The probability distributions of wind speeds and the availability of wind turbines were investigated by considering the vertical wind shear. Based on the wind speed data at the standard height observed at a wind farm,...The probability distributions of wind speeds and the availability of wind turbines were investigated by considering the vertical wind shear. Based on the wind speed data at the standard height observed at a wind farm, the power-law process was used to simulate the wind speeds at a hub height of 60 m. The Weibull and Rayleigh distributions were chosen to express the wind speeds at two different heights. The parameters in the model were estimated via the least square(LS) method and the maximum likelihood estimation(MLE) method, respectively. An adjusted MLE approach was also presented for parameter estimation. The main indices of wind energy characteristics were calculated based on observational wind speed data. A case study based on the data of Hexi area, Gansu Province of China was given. The results show that MLE method generally outperforms LS method for parameter estimation, and Weibull distribution is more appropriate to describe the wind speed at the hub height.展开更多
Based on the fact that the house dust usually falls on the ground, the floor level slit exhaust ventilation system including inlet located at the ceiling and outlet of slit exhaust installed at comer between wall and ...Based on the fact that the house dust usually falls on the ground, the floor level slit exhaust ventilation system including inlet located at the ceiling and outlet of slit exhaust installed at comer between wall and floor was considered. Experiments and simulations were performed to investigate the flow and diffusion fields that are affected by this floor level slit exhaust ventilation system. The characteristics of airflow with experiments and computation fluid dynamics （CFD） are generally similar except airflow at the location of impinging flow and the location right below the inlet. Riboflavin particles were used as the house dust. For the spatial distribution of riboflavin particles in the ventilation system before operation, due to the influence of gravity, different sizes of particles show smooth decay curve. After floor level slit exhaust ventilation system is operated, the decay rate of the particles becomes faster than that after the ventilation system is powered on, and the particles with diameter of 0.5-3.0 μm in the experimental data and calculated values show good agreement.展开更多
The analysis of principal data on Chinese banks highlights how they are exposed to credit risk, primarily generated from loans to public companies. Chinese banks have a good capital provision; The analysis of economic...The analysis of principal data on Chinese banks highlights how they are exposed to credit risk, primarily generated from loans to public companies. Chinese banks have a good capital provision; The analysis of economic data describes a system oriented towards relationship lending; The average profitability per employee shows wide margins of improvement in terms of efficiency and technological equipment. The comparison with the case of Italy, which like China can be considered an economy heavily oriented to banking intermediation, it is useful to highlight some peculiarities of the Chinese banking system.展开更多
This study is designed to explore the impact of LLS （Language Learning Styles） on learning strategy preferences through questionnaire and data analysis. The aim of the study is to make an through investigation of Ch...This study is designed to explore the impact of LLS （Language Learning Styles） on learning strategy preferences through questionnaire and data analysis. The aim of the study is to make an through investigation of Chinese non-English majors＇ learning styles and their learning strategies in English study, and to analyze the impact of learning styles on learning strategy preferences statistically so as to provide empirical evidence in this field, and then present some implications for college English teaching and learning in Chinese context. This study has significance for pedagogy. Teachers should make language learners aware of their own learning styles and strategy preferences and help them select strategies matching their own style preferences in second language learning. It is hoped that this study can benefit language teachers, learners, and researchers to some extent and can spark more teaching research in the future.展开更多
基金Project(51165019)supported by the National Natural Science Foundation of ChinaProject(1308RJYA018)supported by Gansu Provincial Natural Science Fund,ChinaProject(2013-4-110)supported by Lanzhou Technology Development Program,China
文摘The probability distributions of wind speeds and the availability of wind turbines were investigated by considering the vertical wind shear. Based on the wind speed data at the standard height observed at a wind farm, the power-law process was used to simulate the wind speeds at a hub height of 60 m. The Weibull and Rayleigh distributions were chosen to express the wind speeds at two different heights. The parameters in the model were estimated via the least square(LS) method and the maximum likelihood estimation(MLE) method, respectively. An adjusted MLE approach was also presented for parameter estimation. The main indices of wind energy characteristics were calculated based on observational wind speed data. A case study based on the data of Hexi area, Gansu Province of China was given. The results show that MLE method generally outperforms LS method for parameter estimation, and Weibull distribution is more appropriate to describe the wind speed at the hub height.
基金Project supported by Ministry of Land, Infrastructure, Transport and Tourism of Japan Project(DUT10RC(3)103) supported by the Fundamental Research Funds for the Central Universities in China+2 种基金 Project(20111027) supported by the Liaoning Provincial Scientific Research Foundation, China Key Project (2012BAJ02B05) supported by the Twelfth Five-Year National Technology Program of China Project supported by Dalian Municipal Construction Technology Program, China
文摘Based on the fact that the house dust usually falls on the ground, the floor level slit exhaust ventilation system including inlet located at the ceiling and outlet of slit exhaust installed at comer between wall and floor was considered. Experiments and simulations were performed to investigate the flow and diffusion fields that are affected by this floor level slit exhaust ventilation system. The characteristics of airflow with experiments and computation fluid dynamics （CFD） are generally similar except airflow at the location of impinging flow and the location right below the inlet. Riboflavin particles were used as the house dust. For the spatial distribution of riboflavin particles in the ventilation system before operation, due to the influence of gravity, different sizes of particles show smooth decay curve. After floor level slit exhaust ventilation system is operated, the decay rate of the particles becomes faster than that after the ventilation system is powered on, and the particles with diameter of 0.5-3.0 μm in the experimental data and calculated values show good agreement.
文摘The analysis of principal data on Chinese banks highlights how they are exposed to credit risk, primarily generated from loans to public companies. Chinese banks have a good capital provision; The analysis of economic data describes a system oriented towards relationship lending; The average profitability per employee shows wide margins of improvement in terms of efficiency and technological equipment. The comparison with the case of Italy, which like China can be considered an economy heavily oriented to banking intermediation, it is useful to highlight some peculiarities of the Chinese banking system.
文摘This study is designed to explore the impact of LLS （Language Learning Styles） on learning strategy preferences through questionnaire and data analysis. The aim of the study is to make an through investigation of Chinese non-English majors＇ learning styles and their learning strategies in English study, and to analyze the impact of learning styles on learning strategy preferences statistically so as to provide empirical evidence in this field, and then present some implications for college English teaching and learning in Chinese context. This study has significance for pedagogy. Teachers should make language learners aware of their own learning styles and strategy preferences and help them select strategies matching their own style preferences in second language learning. It is hoped that this study can benefit language teachers, learners, and researchers to some extent and can spark more teaching research in the future.
