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Multi-objective genetic algorithms based structural optimization and experimental investigation of the planetcarrier in wind turbine gearbox

Pengxing YI,Lijian DONG,Tielin SHI

《机械工程前沿（英文）》 2014年第9卷第4期页码 354-367 doi: 10.1007/s11465-014-0319-5

摘要：

To improve the dynamic performance and reduce the weight of the planet carrier in wind turbine gearbox, a multi-objective optimization method, which is driven by the maximum deformation, the maximum stress and the minimum mass of the studied part, is proposed by combining the response surface method and genetic algorithms in this paper. Firstly, the design points’ distribution for the design variables of the planet carrier is established with the central composite design (CCD) method. Then, based on the computing results of finite element analysis (FEA), the response surface analysis is conducted to find out the proper sets of design variable values. And a multi-objective genetic algorithm (MOGA) is applied to determine the direction of optimization. As well, this method is applied to design and optimize the planet carrier in a 1.5 MW wind turbine gearbox, the results of which are validated by an experimental modal test. Compared with the original design, the mass and the stress of the optimized planet carrier are respectively reduced by 9.3% and 40%. Consequently, the cost of planet carrier is greatly reduced and its stability is also improved.

关键词： planet carrier multi-objective optimization genetic algorithms wind turbine gearbox modal experiment

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Fault feature extraction of planet gear in wind turbine gearbox based on spectral kurtosis and time wavelet

Yun KONG, Tianyang WANG, Zheng LI, Fulei CHU

《机械工程前沿（英文）》 2017年第12卷第3期页码 406-419 doi: 10.1007/s11465-017-0419-0

摘要：

Planetary transmission plays a vital role in wind turbine drivetrains, and its fault diagnosis has been an important and challenging issue. Owing to the complicated and coupled vibration source, time-variant vibration transfer path, and heavy background noise masking effect, the vibration signal of planet gear in wind turbine gearboxes exhibits several unique characteristics: Complex frequency components, low signal-to-noise ratio, and weak fault feature. In this sense, the periodic impulsive components induced by a localized defect are hard to extract, and the fault detection of planet gear in wind turbines remains to be a challenging research work. Aiming to extract the fault feature of planet gear effectively, we propose a novel feature extraction method based on spectral kurtosis and time wavelet energy spectrum (SK-TWES) in the paper. Firstly, the spectral kurtosis (SK) and kurtogram of raw vibration signals are computed and exploited to select the optimal filtering parameter for the subsequent band-pass filtering. Then, the band-pass filtering is applied to extrude periodic transient impulses using the optimal frequency band in which the corresponding SK value is maximal. Finally, the time wavelet energy spectrum analysis is performed on the filtered signal, selecting Morlet wavelet as the mother wavelet which possesses a high similarity to the impulsive components. The experimental signals collected from the wind turbine gearbox test rig demonstrate that the proposed method is effective at the feature extraction and fault diagnosis for the planet gear with a localized defect.

关键词： wind turbine planet gear fault feature extraction spectral kurtosis time wavelet energy spectrum

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Visible-light-driven heterostructured g-CN/Bi-TiO floating photocatalyst with enhanced charge carrier

《环境科学与工程前沿（英文）》 2021年第15卷第6期 doi: 10.1007/s11783-021-1417-3

摘要：

• Bi doping in TiO₂ enhanced the separation of photo-generated electron-hole.

关键词： Bi doping Visible light Algal removal Charge carrier separation

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Charge-carrier photogeneration and extraction dynamics of polymer solar cells probed by a transient photocurrent

Boa Jin, Hyunmin Park, Yang Liu, Leijing Liu, Jongdeok An, Wenjing Tian, Chan Im

《化学科学与工程前沿（英文）》 2021年第15卷第1期页码 164-179 doi: 10.1007/s11705-020-1976-z

摘要： To understand the complex behaviors of photogenerated charge carriers within polymer-based bulk-heterojunction-type solar cells, the charge-carrier photogeneration and extraction dynamics are simultaneously estimated using a transient photocurrent technique under various external-bias voltages, and a wide range of excitation intensities are analyzed. For this purpose, conventional devices with 80 nm thick active layers consisting of a blend of representative P3HT and PTB7 electron-donating polymers and proper electron-accepting fullerene derivatives were used. After the correction for the saturation behavior at a high excitation-intensity range nearby the regime of the space charge-limited current, the incident-photon-density-dependent maximum photocurrent densities at the initial peaks are discussed as the proportional measures of the charge-carrier-photogeneration facility. By comparing the total number of the extracted charge carriers to the total number of the incident photons and the number of the initially photogenerated charge carriers, the external quantum efficiencies as well as the extraction quantum efficiencies of the charge-carrier collection during a laser-pulse-induced transient photocurrent process were obtained. Subsequently, the charge-carrier concentration-dependent mobility values were obtained, and they are discussed in consideration of the additional influences of the charge-carrier losses from the device during the charge-carrier extraction that also affects the photocurrent-trace shape.

关键词： charge-carrier photogeneration transient photocurrent polymer solar cells charge-carrier extraction space charge-limited current

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Effects of carrier-attached biofilm on oxygen transfer efficiency in a moving bed biofilm reactor

Yanling WEI,Xunfei YIN,Lu QI,Hongchen WANG,Yiwei GONG,Yaqian LUO

《环境科学与工程前沿（英文）》 2016年第10卷第3期页码 569-577 doi: 10.1007/s11783-015-0822-x

摘要： Three laboratory-scale moving bed biofilm reactors (MBBR) with different carrier filling ratios ranging from 40% to 60% were used to study the effects of carrier-attached biofilm on oxygen transfer efficiency. In this study, we evaluated the performance of three MBBRs in degrading chemical oxygen demand and ammonia. The three reactors removed more than 95% of -N at an air flow-rate of 60 L·h . The standard oxygen transfer efficiency (αSOTE) of the three reactors was also investigated at air flow-rates ranging from 60 to 100 L·h . These results were compared to αSOTE of wastewater with a clean carrier (no biofilm attached). Results showed that under these process conditions, αSOTE decreased by approximately 70% as compared to αSOTE of wastewater at a different carrier-filling ratio. This indicated that the biofilm attached to the carrier had a negative effect on αSOTE. Mechanism analysis showed that the main inhibiting effects were related to biofilm flocculants and soluble microbial product (SMP). Biofilm flocs could decrease αSOTE by about 20%, and SMP could decrease αSOTE by 30%–50%.

关键词： carrier biofilm oxygen transfer efficiency moving bed biofilm reactor

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Effects of BTA2 as the third component on the charge carrier generation and recombination behavior of

Leijing Liu, Hao Zhang, Bo Xiao, Yang Liu, Bin Xu, Chen Wang, Shanpeng Wen, Erjun Zhou, Gang Chen, Chan Im, Wenjing Tian

《化学科学与工程前沿（英文）》 2021年第15卷第1期页码 127-137 doi: 10.1007/s11705-020-1936-7

摘要： Effects of a benzotriazole (BTA)-based small molecule, BTA2, as the third component on the charge carrier generation and recombination behavior of poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]] (PTB7):[6,6]-phenyl-C -butyric acid methyl ester (PC BM) organic solar cells (OSCs) were investigated by optical simulation of a transfer matrix model (TMM), photo-induced charge extraction by linearly increasing voltage (photo-CELIV) technique, atomic force microscope (AFM), and the Onsager–Braun model analysis. BTA2 is an A A D A A -type non-fullerene small molecule with thiazolidine-2,4-dione, BTA, and indacenodithiophene as the terminal acceptor (A ), bridge acceptor (A ), and central donor (D), respectively. The short-circuit current density of the OSCs with BTA2 can be enhanced significantly owing to a complementary absorption spectrum. The optical simulation of TMM shows that the ternary OSCs exhibit higher internal absorption than the traditional binary OSCs without BTA2, resulting in more photogenerated excitons in the ternary OSCs. The photo-CELIV investigation indicates that the ternary OSCs suffer higher charge trap-limited bimolecular recombination than the binary OSCs. AFM images show that BTA2 aggravates the phase separation between the donor and the acceptor, which is disadvantageous to charge carrier transport. The Onsager-Braun model analysis confirms that despite the charge collection efficiency of the ternary OSCs being lower than that of the binary OSCs, the optimized photon absorption and exciton generation processes of the ternary OSCs achieve an increase in photogenerated current and thus improve power conversion efficiency.

关键词： third component organic solar cells charge carrier generation charge carrier recombination bimolecular recombination

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Nitrogen removal efficiencies and microbial communities in full-scale IFAS and MBBR municipal wastewater treatment plants at high COD:N ratio

Supaporn Phanwilai, Naluporn Kangwannarakul, Pongsak (Lek) Noophan, Tamao Kasahara, Akihiko Terada, Junko Munakata-Marr, Linda Ann Figueroa

《环境科学与工程前沿（英文）》 2020年第14卷第6期 doi: 10.1007/s11783-020-1374-2

摘要： Abstract • Two IFAS and two MBBR full-scale systems (high COD:N ratio 8:1) were characterized. • High specific surface area carriers grew and retained slow-growing nitrifiers. • High TN removal is related to high SRT and low DO concentration in anoxic tanks. The relative locations of AOB, NOB, and DNB were examined for three different kinds of carriers in two types of hybrid biofilm process configurations: integrated fixed-film activated sludge (IFAS) and moving bed biofilm reactor (MBBR) processes. IFAS water resource recovery facilities (WRRFs) used AnodkalnessTM K1 carriers (KC) at Broomfield, Colorado, USA and polypropylene resin carriers (RC) at Fukuoka, Japan, while MBBR WRRFs used KC carriers at South Adams County, Colorado, USA and sponge carriers (SC) at Saga, Japan. Influent COD to N ratios ranged from 8:1 to 15:1. The COD and BOD removal efficiencies were high (96%–98%); NH4+-N and TN removal efficiencies were more varied at 72%–98% and 64%–77%, respectively. The extent of TN removal was higher at high SRT, high COD:N ratio and low DO concentration in the anoxic tank. In IFAS, RC with high specific surface area (SSA) maintained higher AOB population than KC. Sponge carriers with high SSA maintained higher overall bacteria population than KC in MBBR systems. However, the DNB were not more abundant in high SSA carriers. The diversity of AOB, NOB, and DNB was fairly similar in different carriers. Nitrosomonas sp. dominated over Nitrosospira sp. while denitrifying bacteria included Rhodobacter sp., Sulfuritalea sp., Rubrivivax sp., Paracoccus sp., and Pseudomonas sp. The results from this work suggest that high SRT, high COD:N ratio, low DO concentration in anoxic tanks, and carriers with greater surface area may be recommended for high COD, BOD and TN removal in WRRFs with IFAS and MBBR systems.

关键词： IFAS MBBR Anodkalness^TM K1 carrier Polypropylene resin carrier Sponge carrier

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Managing soil quality for humanity and the planet

Rattan LAL

《农业科学与工程前沿（英文）》 2020年第7卷第3期页码 251-253 doi: 10.15302/J-FASE-2020329

摘要：

Rather than a human-centric, the basic strategy of achieving Sustainable Development Goals must be focused on restoring and sustaining planetary processes. The urgency of meeting the demands of the humanity must be reconciled with the necessity of enhancing the environment. Increasing and restoring soil organic matter content of the degraded and depleted soils is critical to strengthening planetary processes.

关键词： soil quality humanity planet climate change soil carbon sequestration food and nutritional security

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Reduction kinetics of SrFeO/CaO∙MnO nanocomposite as effective oxygen carrier for chemical looping partial

《化学科学与工程前沿（英文）》页码 1726-1734 doi: 10.1007/s11705-022-2188-5

摘要： Chemical looping reforming of methane is a novel and effective approach to convert methane to syngas, in which oxygen transfer is achieved by a redox material. Although lots of efforts have been made to develop high-performance redox materials, a few studies have focused on the redox kinetics. In this work, the kinetics of SrFeO_3−δ–CaO∙MnO nanocomposite reduction by methane was investigated both on a thermo-gravimetric analyzer and in a packed-bed microreactor. During the methane reduction, combustion occurs before the partial oxidation and there exists a transition between them. The weight loss due to combustion increases, but the transition region becomes less inconspicuous as the reduction temperature increased. The weight loss associated with the partial oxidation is much larger than that with combustion. The rate of weight loss related to the partial oxidation is well fitted by the Avrami–Erofeyev equation with n = 3 (A3 model) with an activation energy of 59.8 kJ∙mol^‒1. The rate law for the partial oxidation includes a solid conversion term whose expression is given by the A3 model and a methane pressure-dependent term represented by a power law. The partial oxidation is half order with respect to methane pressure. The proposed rate law could well predict the reduction kinetics; thus, it may be used to design and/or analyze a chemical looping reforming reactor.

关键词： chemical looping reforming SrFeO_3−δ/CaO·MnO nanocomposite reduction kinetics Avrami–Erofeyev model pressure-dependent term

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synthesis of diphenyl carbonate over heterogeneous catalyst: effects of structure of substituted perovskite carrier

WU Guangwen, JIN Fang, WU Yuxin, ZHANG Guangxu, LI Dinghuo, WANG Cunwen, MA Peisheng

《化学科学与工程前沿（英文）》 2007年第1卷第1期页码 59-64 doi: 10.1007/s11705-007-0012-x

摘要： The perovskite-type compound LaMnO was substituted for the part of La in position A and for the part of Mn in position B by citrate method. The phases were detected by X-ray diffraction. Powder morphologies were scanned by scanning electron microscopy. The valence of atoms was determined by X-ray photoelectron spectroscopy. It was found that the perovskite can form crystal defect and increase the proportion of high valence B element by doping. Active component Pd was loaded on various perovskite supports for synthesis of diphenyl carbonate. The results showed that the activities of catalysts in which supports have crystal defect by substitution were higher. It can be concluded that perovskite with defect structure by doping could lead to the formation of oxygen vacancy where the lattice oxygen became exchangeable with the oxygen gas. Also, this improved the redox process of the carrier by transferring electrons and activities of catalysts.

关键词： photoelectron spectroscopy diphenyl carbonate proportion diffraction perovskite

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Effects of pressure and temperature on fixed-site carrier membrane for CO 2 separation from natural gas

Meng WANG, Dongxiao YANG, Zhi WANG, Jixiao WANG, Shichang WANG,

《化学科学与工程前沿（英文）》 2010年第4卷第2期页码 127-132 doi: 10.1007/s11705-009-0231-4

摘要： In this paper, the effect of testing temperature on the performance of fixed carrier membrane for CO separation were studied. The blend composite membranes were developed respectively with a blend of PEI-PVA (polyetheleneimine-polyvinyl alcohol) as separation layer and PS (polysulfone) ultrafiltration membranes as the substrates. The permselectivity of the membranes was measured with CO/CH mixed gas. The effect of testing temperature on membrane separation performance was investigated. The results showed that both the permeances of CO and CH decreased with the increase of temperature, and the permeances decreased more quickly under low pressure than those under high pressure. At the feed pressure of 0.11MPa, the CO/ CH selectivity of PEI-PVA/PS blend composite membrane reduced along with temperature increment. Under the feed pressure of 0.21MPa, as well as 1.11MPa, the selectivity decreased with the increase of temperature.

关键词： temperature increment high pressure permselectivity separation performance temperature

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Cell carrier function of hollow-fiber membrane in rotating wall vessel bioreactor

SONG Kedong, LIU Tianqing, ZHAO Hu, LI Xiangqin, MA Xuehu, CUI Zhanfeng

《化学科学与工程前沿（英文）》 2008年第2卷第1期页码 34-39 doi: 10.1007/s11705-008-0022-3

摘要： Large-scale expansion of the osteoblasts of a Sprague-Dawley (SD) rat was studied in a rotating wall hollow-fiber membrane bioreactor (RWHMB) by using hollow-fiber membrane as the carrier. For the sake of contrast, cells were also expanded in a T-flask using a hollow-fiber membrane as carrier and in a rotating wall vessel bioreactor (RWVB) using a microcarrier. During the culture period, the cells were sampled every 12 h, and after 5 days, the cells were harvested and evaluated with scanning electron microscopy (SEM), hematoxylin-eosin (HE) staining and alkaline phosphatase (ALP) staining. Moreover, von-Kossa staining and Alizarin Red S staining were carried out for mineralized nodules formation. The results show that in RWHMB, the cells present better morphology and vitality and secrete much more extracellular matrix. It is concluded that the RWHMB combines the advantages of the rotating wall vessel and hollow-fiber membrane bioreactors. The hydrodynamic stimulation within it accelerates the metabolism of the osteoblast and mass transfer, which is propitious to cell differentiation and proliferation.

关键词： RWHMB microcarrier hematoxylin-eosin von-Kossa staining propitious

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三维编织锥体织物的减纱技术

朱建勋

《中国工程科学》 2006年第8卷第3期页码 66-69

摘要：

研究了由大端直径开始编织三维锥体织物的减纱技术，包括列向、环向减锭减纱、减细纤维束减纱等多种减纱技术及其组合；分析比较了各种减纱技术对织物结构完整性、操作简便性、机械化编织等方面的影响。减细纤维束减纱技术是特殊的环向减锭技术，具有保持织物结构整体完整、工艺操作简便、纱锭运动可实现机械化等优点，但不同纱束直径纤维编织使织物单元结构构造变得复杂多变。

关键词：三维编织锥体织物减锭减纱减细纤维束减纱单元构造

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对化学链系统中氧载体材料发展的新认识 Review

Zhuo Cheng, Lang Qin, Jonathan A. Fan, Liang-Shih Fan

《工程（英文）》 2018年第4卷第3期页码 343-351 doi: 10.1016/j.eng.2018.05.002

摘要：

化学循环燃烧（CLC）和化学循环重整（CLR）是通过循环氧化还原反应将清洁和有效的碳氢化合物转化为动力、燃料和化学品的创新技术。金属氧化物材料在化学循环氧化还原过程中起着重要作用。在还原过程中，氧载体提供所需量的氧离子用于烃转化和产物合成。在氧化步骤中，耗尽的金属氧化物氧载体从空气中补充分子氧，同时释放热量。近年来，用于各种化学循环应用的氧载体材料已经取得了显着进步。在这些金属氧化物材料中，铁基氧载体由于其高载氧能力、成本效益和化学循环反应应用的多功能性而具有吸引力。它们的反应性也可以通过结构设计和改进来增强。本文讨论了氧载体材料开发的最新进展以及这些材料上烃转化的机制。这些进步将促进氧载体材料的开发，以实现更有效的化学循环技术应用。

关键词：化学循环氧载体烃类转化离子扩散机制

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Modeling of Ce(IV) transport through a dispersion flat combined liquid membrane with carrier P507

Liang PEI,Liming WANG,Zhanying MA

《环境科学与工程前沿（英文）》 2014年第8卷第4期页码 503-509 doi: 10.1007/s11783-013-0540-1

摘要： A mathematical model for the transport of Ce(IV) from hydrochloric acid solutions through dispersion flat combined liquid membrane (DFCLM) with contain 2-ethyl hexyl phosphonic acid-mono-2-ethyl hexyl ester (P507) as the carrier, dissolved in kerosene as the membrane solution have been studied. This process of facilitated transport, based on membrane technology, is a variation on the conventional technique of solvent extraction and may be described mathematically using Fick’s second law. The equations for transport velocity are derived considering the diffusion of P507 and its metallic complexes through the liquid membrane. In this work, the system is considered to be in a transient state, and chemical reaction between Ce(IV) and the carrier to take place only at the solvent–aqueous interfaces. Model concentration profiles are obtained for the Ce(IV), from which extraction velocities are predicted. The experimental and simulated Ce(IV) extractions showed similar tendencies for a high Ce(IV) concentration and acidity case.The model results indicate that high initial Ce(IV) concentrations and acidity both have detrimental effects on Ce(IV) extraction and stripping. The diffusion coefficient of Ce(IV) in the membrane and the thickness of diffusion layer between feed phase and membrane phase are obtained and the values are 6.31 × 10 m ·s and 31.2 μm, respectively. The results are in good agreement with experimental results.

关键词： Dispersion flat combined liquid membrane (DFCLM) dispersion phase feed phase 2-ethyl hexyl phosphonic acid-mono-2-ethyl hexyl ester Ce (IV)

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标题作者时间类型操作

Multi-objective genetic algorithms based structural optimization and experimental investigation of the planetcarrier in wind turbine gearbox

Pengxing YI,Lijian DONG,Tielin SHI

期刊论文

Fault feature extraction of planet gear in wind turbine gearbox based on spectral kurtosis and time wavelet

Yun KONG, Tianyang WANG, Zheng LI, Fulei CHU

期刊论文

Visible-light-driven heterostructured g-CN/Bi-TiO floating photocatalyst with enhanced charge carrier

期刊论文

Charge-carrier photogeneration and extraction dynamics of polymer solar cells probed by a transient photocurrent

Boa Jin, Hyunmin Park, Yang Liu, Leijing Liu, Jongdeok An, Wenjing Tian, Chan Im

期刊论文

Effects of carrier-attached biofilm on oxygen transfer efficiency in a moving bed biofilm reactor

Yanling WEI,Xunfei YIN,Lu QI,Hongchen WANG,Yiwei GONG,Yaqian LUO

期刊论文

Effects of BTA2 as the third component on the charge carrier generation and recombination behavior of

Leijing Liu, Hao Zhang, Bo Xiao, Yang Liu, Bin Xu, Chen Wang, Shanpeng Wen, Erjun Zhou, Gang Chen, Chan Im, Wenjing Tian

期刊论文

Nitrogen removal efficiencies and microbial communities in full-scale IFAS and MBBR municipal wastewater treatment plants at high COD:N ratio

Supaporn Phanwilai, Naluporn Kangwannarakul, Pongsak (Lek) Noophan, Tamao Kasahara, Akihiko Terada, Junko Munakata-Marr, Linda Ann Figueroa

期刊论文

Managing soil quality for humanity and the planet

Rattan LAL

期刊论文

Reduction kinetics of SrFeO/CaO∙MnO nanocomposite as effective oxygen carrier for chemical looping partial

期刊论文

synthesis of diphenyl carbonate over heterogeneous catalyst: effects of structure of substituted perovskite carrier

WU Guangwen, JIN Fang, WU Yuxin, ZHANG Guangxu, LI Dinghuo, WANG Cunwen, MA Peisheng

期刊论文

Effects of pressure and temperature on fixed-site carrier membrane for CO 2 separation from natural gas

Meng WANG, Dongxiao YANG, Zhi WANG, Jixiao WANG, Shichang WANG,

期刊论文

Cell carrier function of hollow-fiber membrane in rotating wall vessel bioreactor

SONG Kedong, LIU Tianqing, ZHAO Hu, LI Xiangqin, MA Xuehu, CUI Zhanfeng

期刊论文

三维编织锥体织物的减纱技术

朱建勋

期刊论文

对化学链系统中氧载体材料发展的新认识

Zhuo Cheng, Lang Qin, Jonathan A. Fan, Liang-Shih Fan

期刊论文

Modeling of Ce(IV) transport through a dispersion flat combined liquid membrane with carrier P507

Liang PEI,Liming WANG,Zhanying MA

期刊论文

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