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31.
对退火炉燃烧过程设计了模糊自寻优控制器,采用自寻优控制,自动搜索最佳油/风比,取得了较好的控制效果,且对不可控因素的干扰具有较好的自适应能力。在保温阶段,比手动控制可节能12%左右。 相似文献
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33.
针对地下工程施工的特点 ,运用监测资料以及反分析技术 ,建立符合地下工程实际特点的、实用的、可操作性强的分析流程及计算机实现过程 ,阐述围岩变形监测与反分析技术相结合的方法及应用 相似文献
34.
对WEB应用系统进行合理的性能测试是保证系统质量的一个重要过程。以某远程教学系统为案例,借助于测试工具Load Runner,从负载反应层面对系统性能进行验证,并对测试结果进行分析,以保证系统的合理优化。 相似文献
35.
To investigate the shut-cut nitrification characteristics of aerobic granule,an aerobic granular sequencing batch airlift reactor(AG-SBAR) was carried out with mixed carbon sources of sodium acetate and glucose at 10±1 ℃.Results indicated that ammonia oxidizing bacteria was accumulated inside the aerobic granules and the reactor performed stably with shut-cut nitrification for a long term at low temperature.During the stable operation period,the effluent ammonia nitrogen concentration was maintained at 13.6 mg/L without nitrate and nitrite when the COD/N ratio was 20:1.However,the effluent concentration of ammonia nitrogen was below 0.5 mg/L with effluent nitrosation ratio of 96.7% on average when the COD/N ratio was reduced to 15:1 and 10:1.And the effluent phosphorus concentration was less than 0.4 mg/L during the stable period with the sludge retention time of 30 d.The phosphorus removal efficiency was not strongly influenced by the adjustment of COD/N ratio in this experiment.The removal efficiencies for COD,NH4+-N and PO43--P were 91.3%-94.6%,97.9%-99.7% and 97.1%-99.5%,respectively. 相似文献
36.
对配电网电容器优化配置进行研究,计及多因素建立了以系统的有功网损费用、电容器投资费用、电容器维护费用和预期中断费用之和为最小的目标函数,采用改进粒子群算法对该问题进行求解.在改进算法中采用自适应惯性权重,并对粒子群速度进行了变异操作,提高了粒子群算法的全局寻优能力.仿真结果表明,该方法使补偿后支出总费用较补偿前降低22.50%;并使得电压质量得到明显改善,各节点的故障率明显减小,其平均故障率可降低13.44%,系统的整体可靠性能得到改善. 相似文献
37.
变压器评估系统根据基础技术数据、运行数据、检修数据等各类数据,分析变压器的工作状态,利用模糊理论的思想,提出一种采用模糊综合评判的方法,对变压器状态进行评估,最终得到状态评估报告,为设备的状态检修决策提供依据。 相似文献
38.
TIAN Li GAO Xiao-li CHEN Xiao-yan ZHONG Da-fang ZHANG Yi-fan DAI Xiao-jian 《Canadian Metallurgical Quarterly》2011,27(2)
A simple, rapid and sensitive liquid chromatography-tandem mass spectrometry(LC-MS/MS) for the determination of glycyrrhetic acid in human plasma with ginsenoside Rh2 as internal standard was developed and validated. The plasma samples were prepared via liquid-liquid extraction with ethyl acetate. Chromatographic separation was accomplished on a Venusil MP-C18(50 mm×2.1 mm, 5μm i.d.) column at 25℃. The mobile phase consisted of acetonitrile/5 mmol·L-1 ammonium acetate(10:90, volume ratio) at a flow rate of 0.4 mL/min. Negative electrospray ionization was utilized as the ionization source. Glycyrrhetic acid and internal standard were determined via the mutiple reaction monitoring of precursor→production ion transitions at m/z 469→425, 409 and m/z 621→161,respectively. Each sample was chromatographed within 2.5 min. The lower limit of uantification was 0.50 ng/mL for 200 μL of plasma sample and the linear range was from 0.50 ng/mL to 800 ng/mL. The intra-and inter-day precisions were less than 8.76% in terms of relative standard deviation(RSD), and the accuracy was within a range of -3.25%-1.32% in terms of relative error(RE). The method was successfully applied to the pharmacokinetic studies of glycyrrhetic acid in healthy male Chinese volunteers after a single oral administration of 75 mg of glycyrrhizin. 相似文献
39.
Low frequency electromagnetic casting(LFEC)process has been developed for years with the application of an induction coil outside the conventional direct chill(DC)casting mould.It has been demonstrated that the LFEC process has a significant grain refining effect on aluminium alloys.However,how it refines the microstructure is still not clearly understood.In the present work,the temperature measurement were carried out to study the temperature field during casting and to understand the mechanism of the grain refining effect of the LFEC process.The results showed that in contrast to the conventional DC casting process,during the LFEC process,the liquid melt flowing from the launder into the mould is cooled with very high cooling rate directly to 3-6℃below the liquidus and the temperature field of the entire melt in the mould and the hot top is quite uniform,which results in enhanced heterogeneous nucleation and improved survival rate of the nuclei.This is believed to be the main reason why the LFEC process can significantly refine the grain size of aluminium alloys. 相似文献
40.
对大型结构件焊接变形的种类和变形原因进行了详细的分析,然后介绍了在生产中单独或综合运用工艺参数法、工装模具法及反变形法,来有效控制大型结构件的焊接变形.通过对大量工程机械部件的生产实践,证明这3种方法均可以有效地控制大型结构件的焊接变形、提高产品质量和合格率. 相似文献