As one of the most important auxiliary systems of a circulating fluidized bed boiler,the limestone pneumatic conveying system is of great significance to its operation.Maldistribution of powder in the different inject...As one of the most important auxiliary systems of a circulating fluidized bed boiler,the limestone pneumatic conveying system is of great significance to its operation.Maldistribution of powder in the different injecting ports seriously limits inner-furnace desulfurization performance owing to inefficient mixing of limestone powder and SO2.The gas-solid flow characteristics of an industrial-scale multiple-branching limestone-conveying pipeline system of a 200 MW circulating fluidized bed boiler were studied using a computational particle fluid dynamics method.The maldistribution intensity was studied under different operating conditions of air velocity and particle mass flow rate.Simulation results indicated that when the air velocity increased,the maldistribution was mitigated,but when the particle mass flow rate increased,the maldistribution strengthened.To solve this problem,two improved schemes were proposed:adding a deflector at different angles and changing the height of pipeline distributor.According to the simulation,the maldistribution could be efficiently mitigated using a distributor height in the range of 100-120 mm and a deflector angle of 10°-30°.展开更多
This paper proposed a T- Y tube model to simulate foe input impedance of arterial system. It improves and extends the asymmetric T-tube model which was firstproposed by O' Rourke[1] and developed laier by Liu et a...This paper proposed a T- Y tube model to simulate foe input impedance of arterial system. It improves and extends the asymmetric T-tube model which was firstproposed by O' Rourke[1] and developed laier by Liu et al.[2]. Based on foe asymmetricT-tube model. a T-Y tube model was proposed by adding branching tubes whichrepresem the iliac arteries.All the tubes are considered to be uniform,viscoelasticlongitudinally tethered cylindrical tubes.The upper tube terminates with a windkesselmodel, while the terminal arterioles of the lowr tube are expressed as a resistance.After proper eraluation of the parameters.the impedance of the arterial system iscalculated under normal physiological and hypertensive condition.The model canpredict impedance in good agreement with the experimentally obtained data no matterin normal physiological condition or in pathological condition In comparison with theasymmeric T-tube model,T- Y tube model is closer to anatomy structure of the human arlerial system and at the sametime much simpler than the extremely complex multiplebranching tube model Therefore it will be a valuable model in studying the influencesof various parameters on aorta impedance and ventricular-vascular coupling.展开更多
Low-resolution face images can be found in many practical applications. For example, faces captured from surveillance videos are typically in small sizes. Existing face recognition deep networks, trained on high-resol...Low-resolution face images can be found in many practical applications. For example, faces captured from surveillance videos are typically in small sizes. Existing face recognition deep networks, trained on high-resolution images, perform poorly in recognizing low-resolution faces. In this work, an improved multi-branch network is proposed by combining ResNet and feature super-resolution modules. ResNet is for recognizing high-resolution facial images and extracting features from both high-and low-resolution images.Feature super-resolution modules are inserted before the classifier of ResNet for low-resolution facial images. They are used to increase feature resolution. The proposed method is effective and simple. Experimental results show that the recognition accuracy for high-resolution face images is high, and the recognition accuracy for low-resolution face images is improved.展开更多
基金the National Natural Science Foundation of China (U1810126).
文摘As one of the most important auxiliary systems of a circulating fluidized bed boiler,the limestone pneumatic conveying system is of great significance to its operation.Maldistribution of powder in the different injecting ports seriously limits inner-furnace desulfurization performance owing to inefficient mixing of limestone powder and SO2.The gas-solid flow characteristics of an industrial-scale multiple-branching limestone-conveying pipeline system of a 200 MW circulating fluidized bed boiler were studied using a computational particle fluid dynamics method.The maldistribution intensity was studied under different operating conditions of air velocity and particle mass flow rate.Simulation results indicated that when the air velocity increased,the maldistribution was mitigated,but when the particle mass flow rate increased,the maldistribution strengthened.To solve this problem,two improved schemes were proposed:adding a deflector at different angles and changing the height of pipeline distributor.According to the simulation,the maldistribution could be efficiently mitigated using a distributor height in the range of 100-120 mm and a deflector angle of 10°-30°.
文摘This paper proposed a T- Y tube model to simulate foe input impedance of arterial system. It improves and extends the asymmetric T-tube model which was firstproposed by O' Rourke[1] and developed laier by Liu et al.[2]. Based on foe asymmetricT-tube model. a T-Y tube model was proposed by adding branching tubes whichrepresem the iliac arteries.All the tubes are considered to be uniform,viscoelasticlongitudinally tethered cylindrical tubes.The upper tube terminates with a windkesselmodel, while the terminal arterioles of the lowr tube are expressed as a resistance.After proper eraluation of the parameters.the impedance of the arterial system iscalculated under normal physiological and hypertensive condition.The model canpredict impedance in good agreement with the experimentally obtained data no matterin normal physiological condition or in pathological condition In comparison with theasymmeric T-tube model,T- Y tube model is closer to anatomy structure of the human arlerial system and at the sametime much simpler than the extremely complex multiplebranching tube model Therefore it will be a valuable model in studying the influencesof various parameters on aorta impedance and ventricular-vascular coupling.
文摘Low-resolution face images can be found in many practical applications. For example, faces captured from surveillance videos are typically in small sizes. Existing face recognition deep networks, trained on high-resolution images, perform poorly in recognizing low-resolution faces. In this work, an improved multi-branch network is proposed by combining ResNet and feature super-resolution modules. ResNet is for recognizing high-resolution facial images and extracting features from both high-and low-resolution images.Feature super-resolution modules are inserted before the classifier of ResNet for low-resolution facial images. They are used to increase feature resolution. The proposed method is effective and simple. Experimental results show that the recognition accuracy for high-resolution face images is high, and the recognition accuracy for low-resolution face images is improved.
