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101.
State of health estimation of lithium‐ion batteries: A multiscale Gaussian process regression modeling approach 下载免费PDF全文
Yi‐Jun He Jia‐Ni Shen Ji‐Fu Shen Zi‐Feng Ma 《American Institute of Chemical Engineers》2015,61(5):1589-1600
Accurate state of health (SOH) estimation in lithium‐ion batteries, which plays a significant role not only in state of charge (SOC) estimation but also in remaining useful life (RUL) prognostics is studied. SOC estimation and RUL prognostics often require one‐step‐ahead and long‐term SOH prediction, respectively. A systematic multiscale Gaussian process regression (GPR) modeling method is proposed to tackle accurate SOH estimation problems. Wavelet analysis method is utilized to decouple global degradation, local regeneration and fluctuations in SOH time series. GPR with the inclusion of time index is utilized to fit the extracted global degradation trend, and GPR with the input of lag vector is designed to recursively predict local regeneration and fluctuations. The proposed method is validated through experimental data from lithium‐ion batteries degradation test. Both one‐step‐ahead and multi‐step‐ahead SOH prediction performances are thoroughly evaluated. The satisfactory results illustrate that the proposed method outperform GPR models without trend extraction. It is thus indicated that the proposed multiscale GPR modeling method can not only be greatly helpful to both RUL prognostics and SOC estimation for lithium‐ion batteries, but also provide a general promising approach to tackle complex time series prediction in health management systems. © 2015 American Institute of Chemical Engineers AIChE J, 61: 1589–1600, 2015 相似文献
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Hongzhi Bai Hui Zi Yuqian Huang Mei Han Muhammad Irfan Ning Liu Jinfeng Yang Hui Wang Xiaori Han 《Catalysis Letters》2017,147(8):2013-2022
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研究了以膨胀石墨(EG)和多壁碳纳米管(MWNT)共同填充聚丙烯(PP)体系的电性能、微观结构及其流变行为。结果表明,EG和MWNT的协同导电作用显著降低了复合材料的体积电阻率和逾渗阀值,当MWNT用量为5 phr、EG为10 phr时,与PP/EG(15 phr)材料相比,复合材料的体积电阻率降低了1 600倍,通过其低频区流变行为的研究,表明EG同MWNT协同形成了更完善的三维网络结构,扫描电镜(SEM)分析表明,MWNT在复合体系中起到桥连作用,连接基体与EG,以及EG片层与片层,因此获得了更好的导电特性。 相似文献
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The radial profiles of axial liquid velocity and gas hold‐ups are investigated in the riser of a pilot plant scale external loop airlift reactor (ELAR) using a modified Pavlov tube and differential pressure technique. The experimental investigation reveals that there exist two different kinds of liquid circulation structures in an ELAR, which has rarely been reported in the literature, namely internal liquid circulation, which exists only in the riser and external liquid circulation, which circulates through the downcomer. A power–law relationship is used to correlate the gas hold‐up and superficial gas velocity, which gives good agreement with experimental data. Experiments for axial liquid velocity profiles are analysed in analogy to a model described for a conventional bubble column. The results predicted by the model are in excellent agreement with the experimental data obtained under various operating conditions. © 2011 Canadian Society for Chemical Engineering 相似文献
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近年来,厌氧氨氧化工艺(anaerobic ammonium oxidation, Anammox)作为一种新型的脱氮技术,由于其耗能少、效率高而被应用于高氨氮废水的处理中。然而,实际运行的厌氧氨氧化工程中有时会出现亚硝酸盐氧化菌(nitrite oxidizing bacteria, NOB)大量繁殖的情况,导致硝酸盐积累,脱氮效率下降。在一段式Anammox反应器中,通过控制某些影响因素,如调节体系中的溶解氧,控制游离氨和游离亚硝酸的浓度,调控碳源浓度以及外加中间产物(N2H4、NO和NH2OH)等方式,能够在维持Anammox工艺脱氮效率的同时有效抑制NOB。除了系统地综述一段式Anammox工艺中NOB抑制手段以外,将进一步讨论实际Anammox工程应用中抑制NOB大量繁殖行之有效的手段。 相似文献
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Chunrong Xiong Qingling Chen Weiran Lu Huanxin Gao Wenkui Lu Zi Gao 《Catalysis Letters》2000,69(3-4):231-236
Novel catalysts for the hydroxylation of phenol, Fe–Si–O, Fe–Mg–O and Fe–Mg–Si–O complex oxides, have been synthesized by
a coprecipitation method. X‐ray diffraction studies show that MgFe2O4 crystallites with spinel structure are formed in Fe–Mg–Si–O and Fe–Mg–O complex oxides and the crystallite size of the metal
oxide or complex oxide is reduced after addition of Si. In the hydroxylation of phenol with hydrogen peroxide, Fe‐based complex
oxides exhibit high activities after a short induction period. The phenol conversion is improved when silicon is introduced
into the Fe‐based complex oxides, and formation of MgFe2O4 crystals with spinel structure in the catalysts increases the diphenol selectivity. The addition of a little acetic acid
to the reaction liquid can shorten the induction period effectively. Under the same reaction conditions, phenol conversion
and diphenol selectivity over the Fe–Mg–Si–O catalyst are close to those over TS‐1, and furthermore, the reaction time is
more than ten times shorter as compared to TS‐1. The reaction mechanism of the hydroxylation of phenol on the catalysts has
been studied, and a free‐radical mechanism initiated by the formation of phenoxy free radicals is suggested.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献