Mathematical models for burden descending process have been applied to obtain whole burden structures in blast furnace,whereas the accuracy of those burden descent models has not been sufficiently investigated.Special...Mathematical models for burden descending process have been applied to obtain whole burden structures in blast furnace,whereas the accuracy of those burden descent models has not been sufficiently investigated.Special evaluation method based on timeline burden profiles was established to quantitatively evaluate the error between experimental and modeled burden structures.Four existing burden descent models were utilized to describe the burden structure of a 1/20 scaled warm blast furnace.Input modeling conditions including initial burden profile,descending volumes in each time interval,and normalized descending velocity distribution were determined via special image processing technology.Modeled burden structures were evaluated combined with the published experimental data.It is found that all the models caught the main profile of the burden structure.Furthermore,the improved nonuniform descent model（Model IV）shows the highest level of precision especially when burden descends with unstable velocity distribution tendency.Meanwhile,the traditional nonuniform descent model（Model III）may also be desirable to model the burden descending process when the burden descending velocity presents a linear tendency.Finally,the uniform descent model（Model I）might be the first option for roughly predicting burden structure.展开更多
ZnO nano-structural films are prepared by RF magnetron sputtering and the hydrothermal synthesis.The morphologies,crystal structures and chemical compositions of the ZnO nano-scaled films are analyzed by XRD,SEM and X...ZnO nano-structural films are prepared by RF magnetron sputtering and the hydrothermal synthesis.The morphologies,crystal structures and chemical compositions of the ZnO nano-scaled films are analyzed by XRD,SEM and XPS,which show that the ZnO nanorods are well oriented along c-axis as the preparation conditions are suitably selected;and there are a lot of oxygen vacancies and adsorbed oxygen atoms in the ZnO nano-structural films,which are beneficial to be utilized as gas-sensing materials.Furthermore,SAW（Rayleigh wave and Love wave） sensors based on ZnO nano-structural films deposited on 128°YX-LiNbO_3 and 36°YX-LiTaO_3 piezoelectric substrates are fabricated and used for sensing hydrogen at room temperature.The results show that the Love wave sensors have better sensing properties,such as high sensitivities and superior performances.展开更多
基金Item Sponsored by National Natural Science Foundation of China(61290325)
文摘Mathematical models for burden descending process have been applied to obtain whole burden structures in blast furnace,whereas the accuracy of those burden descent models has not been sufficiently investigated.Special evaluation method based on timeline burden profiles was established to quantitatively evaluate the error between experimental and modeled burden structures.Four existing burden descent models were utilized to describe the burden structure of a 1/20 scaled warm blast furnace.Input modeling conditions including initial burden profile,descending volumes in each time interval,and normalized descending velocity distribution were determined via special image processing technology.Modeled burden structures were evaluated combined with the published experimental data.It is found that all the models caught the main profile of the burden structure.Furthermore,the improved nonuniform descent model（Model IV）shows the highest level of precision especially when burden descends with unstable velocity distribution tendency.Meanwhile,the traditional nonuniform descent model（Model III）may also be desirable to model the burden descending process when the burden descending velocity presents a linear tendency.Finally,the uniform descent model（Model I）might be the first option for roughly predicting burden structure.
基金supported by the National Natural Science Foundation of China(11304160)Natural Science Foundation of Jiangsu Higher Education Institutions of China(13KJB140008)Foundation of Nanjing University of Posts and Telecommunications(NY213018)
文摘ZnO nano-structural films are prepared by RF magnetron sputtering and the hydrothermal synthesis.The morphologies,crystal structures and chemical compositions of the ZnO nano-scaled films are analyzed by XRD,SEM and XPS,which show that the ZnO nanorods are well oriented along c-axis as the preparation conditions are suitably selected;and there are a lot of oxygen vacancies and adsorbed oxygen atoms in the ZnO nano-structural films,which are beneficial to be utilized as gas-sensing materials.Furthermore,SAW（Rayleigh wave and Love wave） sensors based on ZnO nano-structural films deposited on 128°YX-LiNbO_3 and 36°YX-LiTaO_3 piezoelectric substrates are fabricated and used for sensing hydrogen at room temperature.The results show that the Love wave sensors have better sensing properties,such as high sensitivities and superior performances.
