In order to study the propagation mechanism of continuous rotating detonation wave,the H2/air continuous rotating detonation engine ignited by tangentially installed H2/O2pre-detonation tube is studied experimentally ...In order to study the propagation mechanism of continuous rotating detonation wave,the H2/air continuous rotating detonation engine ignited by tangentially installed H2/O2pre-detonation tube is studied experimentally using a tilt slot injector structure.The experimental results show that the stable rotating detonation wave can be gained successfully with the equivalent ratio of 0.93.The propagation frequency and velocity of rotating detonation wave range from 5200 to 5500 Hz and from 1518.5 to 1606.1 m/s,respectively.Three propagation modes,such as rotation,reversal and bifurcation,of detonation wave are verified through the analysis of propagation mechanism of rotating detonation wave.展开更多
The paper introduces the performances of magnetostrictive actuators and its applications,discusses the design methods for the structure and internal magnetic circuit of a giant magnetostrictive actuator,and makes test...The paper introduces the performances of magnetostrictive actuators and its applications,discusses the design methods for the structure and internal magnetic circuit of a giant magnetostrictive actuator,and makes tests on the output displacement and force characteristics for an actuator using homemade magnetostrictive material.The experimental result shows that the actuator has satisfactory output precisions and ranges in transient and stable states,and can be used in low-frequency vibration control system of precise equipment.展开更多
本文针对重载铁路线路关键区段夜间视频监控图像光照不足、对比度低、细节模糊等问题,提出了一种基于强度-正交色度颜色空间的改进图像亮度增强方法(Low Light Enhancement for Railway surveillance video image based on improved Col...本文针对重载铁路线路关键区段夜间视频监控图像光照不足、对比度低、细节模糊等问题,提出了一种基于强度-正交色度颜色空间的改进图像亮度增强方法(Low Light Enhancement for Railway surveillance video image based on improved Color space transform method,LLERC)。该方法首先将输入图像从RGB(Red,Green,Blue)颜色空间转换至所提出的改进IOC(Intensity-Orthometric-Chroma)颜色空间,以提取其强度和正交色度信息。随后,利用改进的轻量化双路U-net提取IOC颜色空间图像的特征,并预测实现亮度增强所需的强度残差和色度调整量。最后,将上述强度残差与输入图像叠加,得到光照增强后的IOC颜色空间图像,再将其转换为RGB颜色空间图像输出。将LLERC应用于重载铁路试验段,结果表明:LLERC方法在对比度、图像自然度、图像亮度顺序差异等指标上均优于传统图像增强方法和主流深度学习方法,并能有效提升重载铁路夜间视频监控图像的清晰度和自然程度。展开更多
基金sponsored by National Defence Researching Fund(9140c300202120c30)the Fundamental Research Fund for the central Universities(30920130112007)
文摘In order to study the propagation mechanism of continuous rotating detonation wave,the H2/air continuous rotating detonation engine ignited by tangentially installed H2/O2pre-detonation tube is studied experimentally using a tilt slot injector structure.The experimental results show that the stable rotating detonation wave can be gained successfully with the equivalent ratio of 0.93.The propagation frequency and velocity of rotating detonation wave range from 5200 to 5500 Hz and from 1518.5 to 1606.1 m/s,respectively.Three propagation modes,such as rotation,reversal and bifurcation,of detonation wave are verified through the analysis of propagation mechanism of rotating detonation wave.
基金Sponsored by National Nature Science Foundation of China(50005020)Youth Foundation Support Project of Ningbo Province(02J20102-07)
文摘The paper introduces the performances of magnetostrictive actuators and its applications,discusses the design methods for the structure and internal magnetic circuit of a giant magnetostrictive actuator,and makes tests on the output displacement and force characteristics for an actuator using homemade magnetostrictive material.The experimental result shows that the actuator has satisfactory output precisions and ranges in transient and stable states,and can be used in low-frequency vibration control system of precise equipment.
文摘本文针对重载铁路线路关键区段夜间视频监控图像光照不足、对比度低、细节模糊等问题,提出了一种基于强度-正交色度颜色空间的改进图像亮度增强方法(Low Light Enhancement for Railway surveillance video image based on improved Color space transform method,LLERC)。该方法首先将输入图像从RGB(Red,Green,Blue)颜色空间转换至所提出的改进IOC(Intensity-Orthometric-Chroma)颜色空间,以提取其强度和正交色度信息。随后,利用改进的轻量化双路U-net提取IOC颜色空间图像的特征,并预测实现亮度增强所需的强度残差和色度调整量。最后,将上述强度残差与输入图像叠加,得到光照增强后的IOC颜色空间图像,再将其转换为RGB颜色空间图像输出。将LLERC应用于重载铁路试验段,结果表明:LLERC方法在对比度、图像自然度、图像亮度顺序差异等指标上均优于传统图像增强方法和主流深度学习方法,并能有效提升重载铁路夜间视频监控图像的清晰度和自然程度。
