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Rule acquisition of three-way semi-concept lattices in formal decision context
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作者 Jie Zhao Renxia Wan +1 位作者 Duoqian Miao Boyang Zhang 《CAAI Transactions on Intelligence Technology》 SCIE EI 2024年第2期333-347,共15页
Three-way concept analysis is an important tool for information processing,and rule acquisition is one of the research hotspots of three-way concept analysis.However,compared with three-way concept lattices,three-way ... Three-way concept analysis is an important tool for information processing,and rule acquisition is one of the research hotspots of three-way concept analysis.However,compared with three-way concept lattices,three-way semi-concept lattices have three-way operators with weaker constraints,which can generate more concepts.In this article,the problem of rule acquisition for three-way semi-concept lattices is discussed in general.The authors construct the finer relation of three-way semi-concept lattices,and propose a method of rule acquisition for three-way semi-concept lattices.The authors also discuss the set of decision rules and the relationships of decision rules among object-induced three-way semi-concept lattices,object-induced three-way concept lattices,classical concept lattices and semi-concept lattices.Finally,examples are provided to illustrate the validity of our conclusions. 展开更多
关键词 finer relation rule acquisition three-way concept analysis three-way semi-concept lattices
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Three-Way Behavioral Decision Making With Hesitant Fuzzy Information Systems:Survey and Challenges 被引量:1
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作者 Jianming Zhan Jiajia Wang +1 位作者 Weiping Ding Yiyu Yao 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2023年第2期330-350,共21页
Three-way decision(T-WD)theory is about thinking,problem solving,and computing in threes.Behavioral decision making(BDM)focuses on effective,cognitive,and social processes employed by humans for choosing the optimal o... Three-way decision(T-WD)theory is about thinking,problem solving,and computing in threes.Behavioral decision making(BDM)focuses on effective,cognitive,and social processes employed by humans for choosing the optimal object,of which prospect theory and regret theory are two widely used tools.The hesitant fuzzy set(HFS)captures a series of uncertainties when it is difficult to specify precise fuzzy membership grades.Guided by the principles of three-way decisions as thinking in threes and integrating these three topics together,this paper reviews and examines advances in three-way behavioral decision making(TW-BDM)with hesitant fuzzy information systems(HFIS)from the perspective of the past,present,and future.First,we provide a brief historical account of the three topics and present basic formulations.Second,we summarize the latest development trends and examine a number of basic issues,such as one-sidedness of reference points and subjective randomness for result values,and then report the results of a comparative analysis of existing methods.Finally,we point out key challenges and future research directions. 展开更多
关键词 Hesitant fuzzy information system(HFIS) prospect theory regret theory three-way decision(T-WD)
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Stress and Fracture Strength Analysis for Three-Way Pipes 被引量:3
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作者 XU Jing-jing, WU Yi-min School of Electromechanical Engineering and Automation, Shanghai University, Shanghai 200072, China 《Advances in Manufacturing》 SCIE CAS 2000年第S1期11-15,共5页
Three-way pipes, T and Y pipes, are very important connecting components in pipeline systems, their strength are related to the safety of pipelines. In the case that crack is not detected in the three-way pipe, ANSYS ... Three-way pipes, T and Y pipes, are very important connecting components in pipeline systems, their strength are related to the safety of pipelines. In the case that crack is not detected in the three-way pipe, ANSYS finite element program version 5.6 is applied to study the stress distribution of the three-way pipe and to obtain the optimum fillet radius in the crotch region of the two pipes. The reasonable intersection angle of the two pipes is also obtained. In the case that a surface crack is detected in the three-way pipe, the maximum stress intensity factor (SIF) near the front of the surface crack is studied. 展开更多
关键词 three-way pipes intersection angle CRACK fracture strength stress intensity factor (SIF) Kscc
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Quaternary Oxide of Cerium, Terbium, Praseodymium and Zirconium for Three-Way Catalysts 被引量:3
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作者 康振晋 康振川 《Journal of Rare Earths》 SCIE EI CAS CSCD 2006年第3期314-319,共6页
Oxygen storage-capacity (OSC), oxygen buffer capacity (OBC), X-my diffraction and electron diffraction pattern, high resolution electron microscopy were used to study the quaternary oxides, i .e., of Ce, Tb, Pr an... Oxygen storage-capacity (OSC), oxygen buffer capacity (OBC), X-my diffraction and electron diffraction pattern, high resolution electron microscopy were used to study the quaternary oxides, i .e., of Ce, Tb, Pr and Zr. (Ce0.6 Tb0.2Zr0.2O2- δ and Ce0.6Pr0.2Zr0.2O2-δ ). OSC and OBC data indicate that these oxides have very good oxygen transfer capacity (OTC) and their pseudo-solid solutions exhibit fluorite-type structure. These oxides may act as a good candidate for three-way catalysts (TWC). 展开更多
关键词 oxygen storage capacity oxygen buffer capacity three-way catalysts rare earths
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An adaptive dwell time scheduling model for phased array radar based on three-way decision 被引量:3
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作者 LI Bo TIAN Linyu +1 位作者 CHEN Daqing LIANG Shiyang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2020年第3期500-509,共10页
Real-time resource allocation is crucial for phased array radar to undertake multi-task with limited resources,such as the situation of multi-target tracking,in which targets need to be prioritized so that resources c... Real-time resource allocation is crucial for phased array radar to undertake multi-task with limited resources,such as the situation of multi-target tracking,in which targets need to be prioritized so that resources can be allocated accordingly and effectively.A three-way decision-based model is proposed for adaptive scheduling of phased radar dwell time.Using the model,the threat posed by a target is measured by an evaluation function,and therefore,a target is assigned to one of the three possible decision regions,i.e.,positive region,negative region,and boundary region.A different region has a various priority in terms of resource demand,and as such,a different radar resource allocation decision is applied to each region to satisfy different tracking accuracies of multi-target.In addition,the dwell time scheduling model can be further optimized by implementing a strategy for determining a proper threshold of three-way decision making to optimize the thresholds adaptively in real-time.The advantages and the performance of the proposed model have been verified by experimental simulations with comparison to the traditional twoway decision model and the three-way decision model without threshold optimization.The experiential results demonstrate that the performance of the proposed model has a certain advantage in detecting high threat targets. 展开更多
关键词 phased array radar resource scheduling three-way decision threat assessment
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Durability of three-way and close-coupled catalysts for Euro IV regulation 被引量:2
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作者 贾莉伟 沈美庆 +3 位作者 王军 王家明 褚霞 顾炜炜 《Journal of Rare Earths》 SCIE EI CAS CSCD 2008年第6期827-830,共4页
The durability of three-way catalyst (TWC) and corresponding close-coupled catalyst (CCC) for Euro Ⅳ stage regulation was investigated through Vehicle Road Running Mode tests, whereas emissions of regulated pollu... The durability of three-way catalyst (TWC) and corresponding close-coupled catalyst (CCC) for Euro Ⅳ stage regulation was investigated through Vehicle Road Running Mode tests, whereas emissions of regulated pollutants of three car fleet were investigated at every 100,000 km miles. The results showed that HC, NOx, and CO emission values could meet Euro Ⅳ regulation limits at every point. The redox properties of TWC and CCC were measured by CO reduction during each isothermal. It was obvious that both aged TWC and aged CCC behaved a good redox property at 673 and 773 K. Based on XRD and BET measurement results, TWC and CCC washcoat were characterized with good thermal stability. 展开更多
关键词 three-way catalyst DURABILITY redox property emission control regulations rare earths
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Influences of (Ce-Zr-La-Pr)O Contents on Three-Way Catalyst Performances 被引量:1
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作者 张爱敏 宁平 马丽萍 《Journal of Rare Earths》 SCIE EI CAS CSCD 2005年第S1期65-69,共5页
A series of catalysts with (Ce-Zr-La-Pr)O contents range from 0 to 50% in coating and single-palladium loads on substrates were prepared to study effects of (Ce-Zr-La-Pr)O contents on catalytic activities and durabili... A series of catalysts with (Ce-Zr-La-Pr)O contents range from 0 to 50% in coating and single-palladium loads on substrates were prepared to study effects of (Ce-Zr-La-Pr)O contents on catalytic activities and durability by contrasting the characteristics of light-off, A/F and catalytic conversions of the fresh catalysts with that of the aged catalysts. The results show that (Ce-Zr-La-Pr)O can enhance the catalysts light-off characteristics, widen A/F windows and increase catalytic conversions at a certain extent through optimizing physical structural and chemical property of the mixed coating. However, (Ce-Zr-La-Pr)O contents influence greatly on the catalysts activities and durability, and the catalysts with contents ranging from 10% to 30% exhibited better integrative properties in all samples, and 10% was the optical content to make the catalyst performance highest in this thesis. It is indicated that an suitable content of (Ce-Zr-La-Pr)O plays an important role in assisting catalysis, enhancing durability and increasing oxygen storage capability. 展开更多
关键词 (Ce-Zr-La-Pr)O mixed oxide three-way catalyst catalytic activity durability rare earths
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Influence of Ce_(0.35)Zr_(0.55)Y_(0.10) Solid Solution on Performance of Pt-Rh Three-Way Catalysts 被引量:1
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作者 郭家秀 袁书华 +3 位作者 龚茂初 沈美 钟俊波 陈耀强 《Journal of Rare Earths》 SCIE EI CAS CSCD 2007年第2期179-183,共5页
Ce0.35Zr0.55Y0. 10 solid solution was prepared by co-precipitation technique and characterized by specific surface area measurements (BET) and X-ray diffraction (XRD). Ce0.35Zr0.55Y0.10 was used to prepare low Pt-... Ce0.35Zr0.55Y0. 10 solid solution was prepared by co-precipitation technique and characterized by specific surface area measurements (BET) and X-ray diffraction (XRD). Ce0.35Zr0.55Y0.10 was used to prepare low Pt-Rh threeway catalyst (TWC), and its influence on the performance of TWC was investigated. The results revealed that Ce0.35 Zr0.55Y0.10 had a cubic structure similar to Ce0.50Zr0.50O2 and its specific surface area can maintain higher than Ce0.50 Zr0.50O2 after 1000 ℃ calcination for 5 h. Being hydrothermal aged at 1000 ℃ for 5 h, the catalyst containing Ce0.35 Zr0.55Y0.10 still exhibited higher conversion of C3H8, CO and NO and lower light-off temperature in comparison with Ce0.50Zr0.50O2 TWC. 展开更多
关键词 low precious metal three-way catalysts rare earths
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Regulated and Speciated Hydrocarbon Emissions from a Dual Fuel Light Duty Vehicle with and Without a Three-Way Catalyst 被引量:1
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作者 丁焰 葛蕴珊 +2 位作者 王军方 谭建伟 尤可为 《Journal of Beijing Institute of Technology》 EI CAS 2010年第1期31-36,共6页
The regulated pollutants (CO,HC and NOx) and unregulated pollutants (volatile organic compounds and carbonyl compounds),emitted from a dual fuel vehicle fueled with gasoline and E10 fuel,are measured under a trans... The regulated pollutants (CO,HC and NOx) and unregulated pollutants (volatile organic compounds and carbonyl compounds),emitted from a dual fuel vehicle fueled with gasoline and E10 fuel,are measured under a transient cycle and steady modes.The impacts of a three-way catalyst (TWC) are investigated for the two types of fuels.The measured results show that NOx and acetaldehyde emitted from the E10-fueled car are much more than that from the gasoline-fueled car under the same modes.On the basis of maximum incremental reactivity (MIR) factors and emissions of organic gases,the ozone specific reactivity of the tailpipe gases are evaluated. 展开更多
关键词 regulated emissions volatile organic compounds (VOCs) CARBONYLS three-way catalyst (TWC)
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Energy Optimization Oriented Three-Way Clustering Algorithm for Cloud Tasks 被引量:1
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作者 Chunmao Jiang Yibing Li Zhicong Li 《Journal of Beijing Institute of Technology》 EI CAS 2018年第2期189-197,共9页
Cloud computing has developed as an important information technology paradigm which can provide on-demand services. Meanwhile,its energy consumption problem has attracted a grow-ing attention both from academic and in... Cloud computing has developed as an important information technology paradigm which can provide on-demand services. Meanwhile,its energy consumption problem has attracted a grow-ing attention both from academic and industrial communities. In this paper,from the perspective of cloud tasks,the relationship between cloud tasks and cloud platform energy consumption is established and analyzed on the basis of the multidimensional attributes of cloud tasks. Furthermore,a three-way clustering algorithm of cloud tasks is proposed for saving energy. In the algorithm,f irst,t he cloud tasks are classified into three categories according to the content properties of the cloud tasks and resources respectively. Next,cloud tasks and cloud resources are clustered according to their computation characteristics( e. g. computation-intensive,data-intensive). Subsequently,greedy scheduling is performed. The simulation results showthat the proposed algorithm can significantly reduce the energy cost and improve resources utilization,compared with the general greedy scheduling algorithm. 展开更多
关键词 cloud computing cloud energy three-way cluster task attributes
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INVESTIGATION ON THE DYNAMIC RESPONSE PERFORMANCE OF A NOVEL THREE-WAY SOLENOID VALVE
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作者 李维 苏岭 +2 位作者 汪映 周龙保 柳泉冰 《Journal of Pharmaceutical Analysis》 SCIE CAS 2006年第1期13-16,20,共5页
Objective A novel high-speed three-way solenoid valve is developed, which is used for the common-rail injection system equipped on DME powered engine. In order to improve the dynamic response performance of the three-... Objective A novel high-speed three-way solenoid valve is developed, which is used for the common-rail injection system equipped on DME powered engine. In order to improve the dynamic response performance of the three-way solenoid. Methods Experimental studies have been conducted to investigate the effects of spool stroke, drive voltage, negative demagnetizing pulse and two drive schemes on the dynamic response performance of the three-way solenoid valve. Results The results show that the dynamic response performance of the three-way solenoid valve can be remarkably improved by shortening the spool stroke and increasing the drive voltage. Simultaneously, the difference between the response time of closing valve and that of opening valve decreases. At each different drive voltage, there exists an optimal negative demagnetizing pulse corresponding to the same positive exciting pulse. At this optimal pulse, the dynamic response performance of the three-way solenoid valve is the best. In addition, the high drive voltage can lead to the smaller optimal negative demagnetizing pulse. It is also indicated from the experiments that the dynamic response performance of the three-way solenoid valve is better when the NO.1 drive scheme is adopted. The lower drive voltage results in the larger difference between the dynamic response performances for the two drive schemes. Conclusion The dynamic response performance of a novel three-way solenoid valve is good. 展开更多
关键词 three-way solenoid valve dynamic response performance common-rail
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Fattening Effects of Two Kinds of Three-way Crossbreeding Commercial Pigs
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作者 Guo Tong Gao Wei +4 位作者 Wu Yan Li Xiaochen Dong Qing Wang Yuan Li Yazhu 《Animal Husbandry and Feed Science》 CAS 2017年第3期138-139,共2页
To understand the fattening performance of Duroc x Landrace×Yorkshire and Duroc×Yorkshire x landrace, 48 individuals of two kinds of three-way crossbreeding lean type commercial pigs were selected to determi... To understand the fattening performance of Duroc x Landrace×Yorkshire and Duroc×Yorkshire x landrace, 48 individuals of two kinds of three-way crossbreeding lean type commercial pigs were selected to determine average daily feed intake, average daily gain and feed gain ratio. The backtat thickness and eye muscle area of pigs were measured at the end of trial. The results showed that Duroc × Landraee × Yorkshire and Dttroc × Yorkshire x Landrace had similar fattening performance, and could be applied under scientific management conditions. The study is of great significance for development of pig industry. 展开更多
关键词 three-way crossbreeding Fattening performance Duroc × Landrace×Yorkshire Duroc x Yorkshire × Landrace PIGS
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Anti-Robinson Structures for Analyzing Three-Way Two-Mode Proximity Data
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作者 Hans-Friedrich Kohn 《Applied Mathematics》 2014年第6期983-1003,共21页
Multiple discrete (non-spatial) and continuous (spatial) structures can be fitted to a proximity matrix to increase the information extracted about the relations among the row and column objects vis-à-vis a repre... Multiple discrete (non-spatial) and continuous (spatial) structures can be fitted to a proximity matrix to increase the information extracted about the relations among the row and column objects vis-à-vis a representation featuring only a single structure. However, using multiple discrete and continuous structures often leads to ambiguous results that make it difficult to determine the most faithful representation of the proximity matrix in question. We propose to resolve this dilemma by using a nonmetric analogue of spectral matrix decomposition, namely, the decomposition of the proximity matrix into a sum of equally-sized matrices, restricted only to display an order-constrained patterning, the anti-Robinson (AR) form. Each AR matrix captures a unique amount of the total variability of the original data. As our ultimate goal, we seek to extract a small number of matrices in AR form such that their sum allows for a parsimonious, but faithful reconstruction of the total variability among the original proximity entries. Subsequently, the AR matrices are treated as separate proximity matrices. Their specific patterning lends them immediately to the representation by a single (discrete non-spatial) ultrametric cluster dendrogram and a single (continuous spatial) unidimensional scale. Because both models refer to the same data base and involve the same number of parameters, estimated through least-squares, a direct comparison of their differential fit is legitimate. Thus, one can readily determine whether the amount of variability associated which each AR matrix is most faithfully represented by a discrete or a continuous structure, and which model provides in sum the most appropriate representation of the original proximity matrix. We propose an extension of the order-constrained anti-Robinson decomposition of square-symmetric proximity matrices to the analysis of individual differences of three-way data, with the third way representing individual data sources. An application to judgments of schematic face stimuli illustrates the method. 展开更多
关键词 Anti-Robinson Structure three-way Data Individual Differences ULTRAMETRIC Unidimensional Scale
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A three-way electrolyte with ternary solvents for high-energy-density and long-cycling lithium-sulfur pouch cells
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作者 Zheng Li Legeng Yu +11 位作者 Chen-Xi Bi Xi-Yao Li JinMa Xiang Chen Xue-Qiang Zhang Aibing Chen Haoting Chen Zuoru Zhang Li-Zhen Fan Bo-Quan Li Cheng Tang Qiang Zhang 《SusMat》 SCIE EI 2024年第2期1-12,共12页
Lithium–sulfur(Li–S)batteries promise high-energy-density potential to exceed the commercialized lithiumion batteries but suffer from limited cycling lifespan due to the side reactions between lithium polysulfides(L... Lithium–sulfur(Li–S)batteries promise high-energy-density potential to exceed the commercialized lithiumion batteries but suffer from limited cycling lifespan due to the side reactions between lithium polysulfides(LiPSs)and Li metal anodes.Herein,a three-way electrolyte with ternary solvents is proposed to enable high-energy-density and long-cycling Li–S pouch cells.Concretely,ternary solvents composed of 1,2-dimethoxyethane,di-isopropyl sulfide,and 1,3,5-trioxane are employed to guarantee smooth cathode kinetics,inhibit the parasitic reactions,and construct a robust solid electrolyte interphase,respectively.The cycling lifespan of Li–S coin cells with 50μm Li anodes and 4.0 mg cm^(−2) sulfur cathodes is prolonged from88 to 222 cycles using the three-way electrolyte.Nano-heterogeneous solvation structure of LiPSs and organic-rich solid electrolyte interphase are identified to improve the cycling stability of Li metal anodes.Consequently,a 3.0 Ah-level Li–S pouch cell with the three-way electrolyte realizes a high energy density of 405 Wh kg^(−1) and undergoes 27 cycles.Thiswork affords a three-way electrolyte recipe for suppressing the side reactions of LiPSs and inspires rational electrolyte design for practical high-energy-density and long-cycling Li–S batteries. 展开更多
关键词 lithium metal anodes lithium-sulfur batteries pouch cells solid electrolyte interphase three-way electrolyte
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Construction of bimetallic Pt-Pd/CeO_(2)-ZrO_(2)-La_(2)O_(3) catalysts with different Pt/Pd ratios and its structure-activity correlations for three-way catalytic performance
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作者 Kai Chen Jie Wan +2 位作者 Ting Wang Qi Sun Renxian Zhou 《Journal of Rare Earths》 SCIE EI CAS CSCD 2023年第6期896-904,I0004,共10页
A series of Pt-Pd bimetallic catalysts supported on CeO_(2)-ZrO_(2)-La_(2)O_(3) mixed oxides were synthesized through the conventional impregnation method.Three-way catalytic performance evaluations along with detaile... A series of Pt-Pd bimetallic catalysts supported on CeO_(2)-ZrO_(2)-La_(2)O_(3) mixed oxides were synthesized through the conventional impregnation method.Three-way catalytic performance evaluations along with detailed physio-chemical characterizations were carried out to establish possible structure-activity correlations.Results show that on the one hand,different Pt/Pd ratios can strongly affect the TWC behaviors of Pt-Pd/CZL catalysts by modulating the synergistic effect between Pt and Pd.On the other hand,higher Pt/Pd ratio also favors better dispersion of precious metals.Such improved precious metals(PM)dispersion can promote the metal-support interaction and increase the surface oxygen vacancies concentration,thereby raising the dynamic oxygen storage/release capacity,improving the redox ability as well as enha ncing the thermal stability of the Pt-Pd/CZL catalyst.Moreover,the stro ng metal-support interaction can augment surface oxygen vacancy concentration,thereby benefiting low temperature CO and NO reaction via augmented NOxadsorption and nitrate conversion. 展开更多
关键词 three-way catalyst BIMETALLIC Metal-support interaction Dispersion Dynamic oxygen storage/release capacity Rare earths
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Low-content and highly effective zoned Rh and Pd three-way catalysts for gasoline particulate filter potentially meeting Euro 7
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作者 Ying Xin Hanxue Zhang +8 位作者 Pan Li Ningning Qu Ahui Tang Fuzhen Yang Dongxu Han Junxiu Jia Jin Wang Lirong Zheng Zhaoliang Zhang 《Journal of Rare Earths》 SCIE EI CAS CSCD 2023年第6期905-916,I0004,共13页
The next-generation Euro 7 standard proposed much lower pollutant limits from gasoline vehicles,specifically for CO and NO_(x),which would be challenging for the three-way catalysts(TWCs)utilized commercially to elimi... The next-generation Euro 7 standard proposed much lower pollutant limits from gasoline vehicles,specifically for CO and NO_(x),which would be challenging for the three-way catalysts(TWCs)utilized commercially to eliminate these pollutants.TWCs with reductive(Rh)and oxidative(Pd)active components on gasoline particulate filters(TWC on GPF)play importantly auxiliary roles in the remediation of CO and NO_(x)downstream the close coupled TWCs to meet their emission targets.Here,a low-content Rh-based TWC(0.17 wt%)zoned with a less expensive Pd-based TWC(0.29 wt%)for GPF applications(cGPF)is reported using improved colloidal deposition method.The supporting of Rh on Y-stabilized ZrO_(2)rather than on CeO_(2)-ZrO_(2)inhibits the formation of inactive Ce rhodate species,while Pd on CeO_(2)-ZrO_(2)not only guarantees the high oxygen storage capacity(OSC)but also enhances catalytic activity.The layout of the front one-fifth in volume being 0.29 wt%Pd on Ce_(0.43)Zr_(0.5)7O_(2)and the rear four-fifths being 0.17 wt%Rh on Zr_(0.85)Y_(0.15)O_(2)prevents the possible alloying of Rh with Pd.The highly effective zoned Rh and Pd TWCs show synergistic three-way activity before and after severe hydrothermal aging at 1000℃with 10%water for24 h,which could be potential choices for close coupled GPF application to satisfy the upcoming stringent emission standards,such as Euro 7 and China 6b. 展开更多
关键词 three-way catalyst Zoned catalyst Ultra-low platinum group metal loading Gasoline particulate filter Oxygen storage capacity Rare earths
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Influence of surface Ce/Zr ratio on formation of κ-Ce_(2)Zr_(2)O_(8) superstructure and its application in three-way catalysis
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作者 Jie Deng Shanshan Li +4 位作者 Xinyi Yin Mengchen Li Jianli Wang Yongdong Chen Yaoqiang Chen 《Journal of Rare Earths》 SCIE EI CAS CSCD 2023年第1期67-76,共10页
Ceria-zirconia based(CZ) materials are still a crucial component of three-way catalysts(TWCs) now.Compared with traditional cubic or tetragonal phase,CZ material with pyrochlore-type κ-Ce_(2)Zr_(2)O_(8) phase shows a... Ceria-zirconia based(CZ) materials are still a crucial component of three-way catalysts(TWCs) now.Compared with traditional cubic or tetragonal phase,CZ material with pyrochlore-type κ-Ce_(2)Zr_(2)O_(8) phase shows an excellent oxygen storage capacity,and thus is examined as a promising material for developing TWCs.Considering the remarkable surface Ce/Zr ratio change during the κ-Ce_(2)Zr_(2)O_(8) formation,we investigated the effects of surface Ce/Zr ratio on the formation of κ-Ce_(2)Zr_(2)O_(8) and on the supported Pdonly three-way catalysts.Raman and transmission electron microscopy(TEM) results demonstrate that partial κ-Ce_(2)Zr_(2)O_(8) structure is formed in the three oxides,and the content of κ-Ce_(2)Zr_(2)O_(8) structure increases with increasing surface Ce/Zr ratio,but its stability declines.After thermal aging,the proportions of Ce^(3+) and oxidized palladium(Pd^(δ+)+Pd^(2+)) in the catalysts,which are shown to be positively correlated with catalytic activity,follow the same sequence as the stability of κ-Ce_(2)Zr_(2)O_(8),namely Pd/M0.33 ROa> Pd/M0.4 ROa> Pd/CeM0.33 ROa.In particular,Pd/M0.33 RO,which possesses 100%((Pd^(δ+)+Pd^(2+))/Pd) even after thermal aging at 900℃ for 4 h,owing to the strengthened metal-support interaction by the presence of stable κ-Ce_(2)Zr_(2)O_(8),shows the best catalytic performance.This work is instructive to the application of κ-Ce_(2)Zr_(2)O_(8) in three-way catalysis. 展开更多
关键词 CERIA-ZIRCONIA κ-Ce_(2)Zr_(2)O_(8) Ce/Zr ratio three-way catalyst Rare earths
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Effect of cobalt doping on ceria-zirconia mixed oxide: Structural characteristics, oxygen storage/release capacity and three-way catalytic performance 被引量:7
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作者 王建强 沈美庆 +3 位作者 王军 高继东 马杰 刘双喜 《Journal of Rare Earths》 SCIE EI CAS CSCD 2012年第9期878-883,共6页
The effect of Co doping on ceria-zirconia mixed oxides was investigated for Co0.1Ce0.6Zr0.3Ox sample prepared by sol-gel method. The Pd-only three-way catalyst (TWC) was obtained by incipient wetness impregnation wi... The effect of Co doping on ceria-zirconia mixed oxides was investigated for Co0.1Ce0.6Zr0.3Ox sample prepared by sol-gel method. The Pd-only three-way catalyst (TWC) was obtained by incipient wetness impregnation with 0.5 wt.% Pd loading. The structural and oxygen handling properties were analyzed by X-ray diffraction (XRD), H2-temperature programmed reduction (H2-TPR) and the dynamic oxygen storage capacity (DOSC). The introduction of Co into ceria-zirconia lattice strongly modified the mobility of oxygen and enhanced the DOSC performance. Pd-only TWC based on the Co0.1Ce0.6Zr0.3Ox support exhibited superior activity for water-gas shift and steam reforming and ampli- fied amplitude of stoichiometric window. 展开更多
关键词 three-way catalyst stoichiometric window dynamic oxygen storage capacity water-gas shift steam reforming Co doping rare earths
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Synthesis of neodymium modified CeO_2-ZrO_2-Al_2O_3 support materials and their application in Pd-only three-way catalysts 被引量:4
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作者 彭娜 周菊发 +3 位作者 陈山虎 罗秀超 陈耀强 龚茂初 《Journal of Rare Earths》 SCIE EI CAS CSCD 2012年第4期342-349,共8页
Ce-Zr-Al-Nd2O3 (CZAN) support materials were prepared by co-precipitation and impregnation methods, respectively. They were characterized by X-ray diffTaction (XRD), low temperature nitrogen adsorption-desorption,... Ce-Zr-Al-Nd2O3 (CZAN) support materials were prepared by co-precipitation and impregnation methods, respectively. They were characterized by X-ray diffTaction (XRD), low temperature nitrogen adsorption-desorption, oxygen pulsing technique, H2-temperamre programmed reduction (H2-TPR) and X-ray photoelectron spectroscopy (XPS). The Pd-only three-way catalysts (Pd-TWC) supported on these materials were prepared by incipient wetness method and studied by activity tests. The results demonstrated that the CZAN supports obtained by the two methods showed better structural, textural and redox properties than the CZA without Nd2O3, and the addition of Nd203 improved the catalytic activity of TWC. Especially, the CZAN-i support prepared by impregnation method had better thermal stability and redox property. Meanwhile, the Pd/CZAN-i catalyst exhibited the best catalytic performance. XPS measurements indicated that the Nd-modified samples possessed more Ce3+ and oxygen vacancies on the surface of samples, which led to a better redox property. The excellent redox property of support materials helped to improve the catalytic activity of TWC. 展开更多
关键词 CeO2-ZrO2-Al2O3 support materials ND2O3 Ce-O-Nd bonds Pd-only three-way catalysts redox property rare earths
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Steam effects over Pd/Ce_(0.67)Zr_(0.33)O_2 three-way catalyst 被引量:3
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作者 王建强 沈美庆 +1 位作者 王军 王务林 《Journal of Rare Earths》 SCIE EI CAS CSCD 2011年第3期217-224,共8页
In the purification process of automobile exhaust,existing water plays an important role as an oxidant,which converts CO and hydrocarbons(HCs) by the water-gas shift(WGS) and the steam reforming(SR) reactions,re... In the purification process of automobile exhaust,existing water plays an important role as an oxidant,which converts CO and hydrocarbons(HCs) by the water-gas shift(WGS) and the steam reforming(SR) reactions,respectively,especially at high temperatures.Meanwhile it is major component of the exhaust which can affect significantly the thermal stability of the three-way catalyst.Activity experiments were carried out close to the real operation conditions(GHSV,concentration,etc.) with a Pd/Ce0.67Zr0.33O2 catalyst supplying information on the CO and C3H8 oxidation reactions in feedstream formed by different reactant combinations.The obtained results showed that the activity of the CO and C3H8 oxidation was promoted by the addition of steam due to the WGS and SR reactions.The WGS and SR reaction were competitive under oxygen-lean conditions.The kinetic analysis was considered for WGS and SR reactions. 展开更多
关键词 three-way catalysts water-gas shift steam reforming turnover frequency compensation effect rare earths
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