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随着环保要求日益严格,对城镇污水处理厂出水水质提出了更高的要求.昌图污水处理厂原设计出水为GB 18918-2002《城镇污水处理厂污染物排放标准》一级B排放标准,且处理工艺单一、工艺流程不完善,再加上项目地处严寒地区,导致出水水质不稳定,亟需进行升级改造.基于该项目现状及存在的主要问题,对原有生化工艺进行升级,将A/O工艺改造为Az/O工艺,并增设"混凝沉淀+纤维转盘过滤"深度处理单元和消毒工艺.研究结果表明:改造后污水处理系统运行稳定、处理效果较好、出水水质可达到GB18918-2002《城镇污水处理厂污染物排放标准》一级A排放标准,该工程实践对寒冷地区污水处理厂升级改造有一定的借鉴意义. 相似文献
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Time-delay of magnetorheological elastomer bearing(MRB) can bring structural response menace to bridges. This paper investigates a bridge pier-bearing semi-active-coupling control method based on model predictive control(MPC). The presented strategy takes the structure prediction model to predict the state responses of the controlled plant in a period of future time. Then, the control law can be determined by solving a finite horizon optimization problem. The peak shearing force of pier top, the displacement and the acceleration of beam are chosen as control goals, and the vibration isolation rate is applied to characterize the vibration isolation effect.It is noted that MPC method naturally takes the time-delay and uncertain interference into consideration, and significantly improves the control performance of the system. Finally, the numerical example is described and the seismic response of isolated bridge based on MRB is analyzed. The simulation results show that predictive control can be used to control the time-delay of bridge system in different degrees. The best control performance is at0.4 s. Even if the time-delay reaches 2 s, it is still good. Therefore, the control method significantly reduces the adverse effects of time-delay on the system, and has a good vibration isolation performance. 相似文献
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地基对铁路A型超高墩刚构连续梁桥的受力影响研究 总被引:1,自引:1,他引:0
为满足铁路桥梁的动力特性要求,同时节省桥墩圬工量,首次将A型桥墩应用于渝利线蔡家沟双线特大桥中。本桥为(80+3×144+80)m刚构-连续组合梁桥,刚构墩采用A型桥墩、三墩固结的结构形式,墩高最高达139m。针对A型超高桥墩的结构受力特点,根据地质条件,计算分析采用合理的桥墩基础形式,并分析其对A型超高墩刚构-连续组合桥的刚度及静、动力特性的影响。结果表明,3种承台结构形式的桥梁结构动力特性均满足要求,但墩底内力差异较大,同时当岩石地基极限抗压强度R4 MPa时,岩石竖向地基系数取值的变化对结构自振周期的影响较小。 相似文献
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整治建筑物对栖息地适合度指数影响的研究 总被引:1,自引:0,他引:1
选择长江中下游地区几种具有代表性的生物,以流速及水深作为参考因子,建立代表生物在丁坝工程建设前的栖息地适合度指数(HSI)模型,并根据生物特点选择合适的模型计算方法。以丁坝为代表性整治建筑物,利用River2D建立人工河道水动力模型,以丁坝的形状,丁坝问的间距为变量,模拟不同工况的水动力条件,分析出不同情况下丁坝对水流条件的影响。最后,将丁坝对流场的改变与HSI相结合,评价整治建筑物对栖息地适合度指数的影响,选择出能使HSI值有所提升的最优丁坝间距,从而对今后的航道建设提出一定建议。 相似文献