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催化裂化主风机组于2004年大修期间将常规仪表控制改造成为ESD系统控制,将原有的控制系统存在的问题和逻辑控制方案进行了修改,主要应用了逻辑块编程方法,使得联锁逻辑的设计和运用简化可靠.完善了联锁逻辑、安全运行程序,防喘振程序.新系统独立的三重冗余功能保证了主风机组控制系统的高可靠性,上位监控画面便于操作人员进行操作记录和过程监控,同时增加的报警记录和实时、历史趋势便于故障的分析和判断. 相似文献
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面部的局部细节信息在面部表情识别中扮演重要角色,然而现有的方法大多只关注面部表情的高层语义信息而忽略了局部面部区域的细粒度信息。针对这一问题,提出一种融合局部特征与两阶段注意力权重学习的深度卷积神经网络FLF-TAWL(deep convolutional neural network fusing local feature and two-stage attention weight learning),它能自适应地捕捉重要的面部区域从而提升面部表情识别的有效性。该FLF-TAWL由双分支框架构成,一个分支从图像块中提取局部特征,另一个分支从整个表情图像中提取全局特征。首先提出了两阶段注意力权重学习策略,第一阶段粗略学习全局和局部特征的重要性权重,第二阶段进一步细化注意力权重,并将局部和全局特征进行融合;其次,采用一种区域偏向损失函数鼓励最重要的区域以获得较高的注意力权重。在FERPlus、Cohn-Kanada(CK+)以及JAFFE三个数据集上进行了广泛实验,分别获得90.92%、98.90%、97.39%的准确率,实验结果验证了FLF-TAWL模型的有效性和可行性。 相似文献
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YANG ZhengJian LIU DeFu JI DaoBin & XIAO ShangBin College of Civil & Hydroelectric Engineering China Three Gorges University Yichang China School of Water Resources & Hydropower Engineering Wuhan University Wuhan 《中国科学:信息科学(英文版)》2010,(4)
The water level of the Three Gorges Reservoir(TGR) rose to 172.5 m in two stages from September to November,2008.The hydrodynamic parameters and water quality parameters(e.g.flow velocity,temperature,turbidity and nutrient content) had been continuously monitored to reveal the influence of the impounding process of the TGR on the water eutrophication in the Xiangxi Bay(XXB).The maximal daily rise of the water level of the TGR was about 2.38 m.The water exchange between the mainstream(the Changjiang River) a... 相似文献
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In this study the transmission probability for Knudsen diffusion through a single chamber-throat pore is simulated by the test-particle Monte Carlo method. The effects of the ratios of the length to the throat radius and the chamber radius to the throat radius on transport properties are investigated. The mechanisms affecting the transmission probability are revealed and discussed in detail. It is found that the transmission probability strongly depends on the ratio of the length to the throat radius of a pore and the transmission probability remarkably decreases with increasing the ratio of the length to throat radius. However, the ratio of the chamber radius to the throat radius has little effect on the transmission probability. 相似文献
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An eco-environmental friendly operation: An effective method to mitigate the harmful blooms in the tributary bays of Three Gorges Reservoir 总被引:2,自引:0,他引:2
YANG ZhengJian LIU DeFu JI DaoBin XIAO ShangBin HUANG YuLing MA Jun 《中国科学:技术科学(英文版)》2013,(6):1458-1470
Harmful algal blooms, which frequently occur in different tributaries, have become a serious water quality problem of the Three Gorges Reservoir (TGR) since its initial filling. A three-year monitoring campaign from 2008 to 2010 was conducted to identify the controlling factors of algal blooms and effective preventive measures. The following results were obtained: 1) Layered and bidirectional currents, called intrusive density currents, dominate the tributary bays of the TGR year round; 2) continuously increasing water level can make the intruding density current shift from the middle to the surface, and surface intrusive water can reduce the surface water temperature and break the stable stratification of the tributary; 3) the appearing or fading away of algal blooms is closely associated with fluctuations in the TGR water level. Thus, the water level fluctuation patterns of different "tide-types" may prevent the occurrence of algal blooms in the spring and summer, and the "stair-type" tides may control autumn blooms during the impounding period. These methods were feasible and effective throughout the actual TGR’s operation in 2009 2011. These patterns formed an eco-environmentally friendly operation (EEFO) to mitigate algal blooms. As an in situ treatment with easier operation and less negative impact and loss, compared with chemical and filter-feeding fish methods, the EEFO is currently considered as the most feasible remedial measure to remit the eco-environmental problems at the Three Gorges Dam (TGD). 相似文献
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