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A novel four-way combining catalysts for simultaneous removal of exhaust pollutants from diesel engine

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Journal of Environmental Sciences 2010年第7期22卷 1104-1109页

作者： Jian Liu,Jie Xu,Zhen Zhao,Aijun Duan,Guiyuan Jiang,Yanni Jing State key laboratory of Heavy Oil {2.,china university of Petroleum,beijing 102.49,china. [a] State key laboratory of Heavy Oil {2. China University of Petroleum Beijing 102249 China

A novel four-way combining catalysts containing double layers was applied to simultaneously remove four kinds of exhaust pollutants （NOx, CO, HC and PM） emitted from diesel engine. The four-way catalysts were characterized using scanning electron microscope （SEM） and Ultraviolet visible diffuse reflectance spectroscopy （UV-Vis DRS）. Their catalytic performances were evaluated by temperature-programmed reaction technology. The double layer catalysts could effectively remove the four main pollutants. The highest catalytic activity was given by the two-layered catalysts of La0.6 K0.4CoO3/Al2.3 and W/HZSM-5. Under the simulated exhaust gases conditions, the peak temperature of the soot combustion was 42.℃, the maximal conversion of NO to N2.was 74%, the temperature of the HC total conversion was 357℃, and the maximum conversion ratio of CO was 99%.

关键词： four-way combining catalyst diesel engine exhaust double layers perovskite oxides zeolite catalysts

Characterization and Corrosion Resistance of Laser Clad-ding Al_2._3-13%TiO_2.Coating on AZ91D Magnesium Alloy

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稀有金属材料与工程 2011年第S4期40卷 221-225页

作者： Qian Jiangang1,Zhang Jiaxiang1,2.Xu Min1,2.Li Shuqing2.1School of Chemistry and Environment,beijing university of Aeronautics and Astronautics,beijing 100191,china2.ational key laboratory for High Energy Density Beam processing technology,beijing 10002.,china beijing Univ Aeronaut & Astronaut Sch Chem & Environm Beijing 100191 Peoples R China Natl key Lab High Energy Dens Beam Proc Technol Beijing 100024 Peoples R China

An Al2.3-13%TiO2.(AT-13) ceramic coating was prepared on an AZ91D Mg alloy substrate by the laser plasma hybrid spraying technique.X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to identify the phases and to study the morphology,*** adhesion strength and the metallographic structure of the coating were measured by using a tensile testing machine and an optical microscope (OM),*** microhardness was measured using a micro Vickers hardness *** results show that after laser remelting,metallurgic bonding occurred at the interface between the Al transition layer and the *** adhesion strength of the coating increased from 17.01 to 2..47 *** coating became *** metastable γ-Al2.3 phase in the coating without laser remelting transformed completely into the stable α-Al2.3 *** microhardness was improved from HV0.052.0 to HV0.0542. and the time of salt spraying increased from 2.8 to 336h.

关键词： laser plasma hybrid spraying Mg alloy corrosion resistance

Research of Laser Cladding Ni-based Alloys on Stainless Steel

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稀有金属材料与工程 2011年第S4期40卷 288-291页

作者： Fei Q X1,2.Cao W B1,Bai F M2.Zhang Y2.Tan Y S2.Department of Inorganic Nonmetallic materials,School of materials Science and Engineering,{2. of Science and technology beijing,beijing 100083,china2.4} Aeronautical manufacturing technology Research Institute,beijing 10002.,china Univ Sci & Technol beijing Sch Mat Sci & Engn Dept Inorgan Nonmetall Mat Beijing 100083 Peoples R China beijing Aeronaut Mfg Technol Res Inst Beijing 100024 Peoples R China

Laser cladding of NiCrBSi coatings on 1Cr18Ni9Ti stainless steel substrate were obtained by high power ***,composition distribution and wear properties of the as-cladded coatings by different laser power were investigated using SEM,EDS and M-2.00 wear resistance *** results show that the coating can be characterized as two regions,cladding and bonding *** cladding zone consists of multiple phases such as γ-(Ni,Fe) and CrB,which presenting several morphologies:dendritic,eutectic,irregular granulated and needle-like *** bonding zone was mixed by NiCrBSi and the melted substrate surface,mainly made up of columnar *** rate increased with the increase of laser *** wear test results show that the wear mechanism of the multi-track clad coatings is abrasive and adhesive *** wear rate is in the range of (2.2.2.6)×10-5mm3/m·N and the average friction coefficient is *** wear resistance decreased when increasing laser *** analysis indicates that the main constitutional compositions of Ni,Fe,Cr and Si homogeneously distribute in the *** fraction was apparently improved in the higher laser power cladded coatings.

关键词： laser cladding Ni-based alloys microstructure wear resistance properties

Synthesis and X-ray Powder Diffraction Characterization of A New Niobate Crystal NaBa_2.i_(0.6)Nb_(4.8)Zn_(0.2.O_(15)

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Journal of Wuhan university of technology({2. Science) 2006年第1期21卷 1-3页

作者：欧阳世翕 State key laboratory of {2. technology for materials Synthesis and processing Wuhan University of Technology Wuhan 430070ChinaChina Building Materials Academy Beijing 100024China

A new niobate compound was synthesized for the first time in Na2.O-BaO-Li2.O-ZnO-Nb2.O5 system by solid state reaction. The acw compound was studied by X-ray diffraction, electron probe, X-ray microanalysis, chemical analysis and SEM. The result of X-ray powder diffraction shows that NaBa2.Li0.6 Nb4.8 Zn0.2.O15 belongs to orthorhombic tungsten bronze structure, with space group Pba2. 32.） and lattice parameters a = 12.6115（2.A, b = 12.4981（2.A, C = 3.9479（3）A. The X-ray powder diffraction lines of the compoutid were well indexed.

关键词： nlobate ziac niobate structure XRD

Diagnosis of Gearbox Typical Fault in Rolling Mills Based on the Wavelet Packets technology

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武汉理工大学学报 2006年第S3期28卷 1042-1045页

作者： CUI Lingli GAO Lixin ZHANG Jianyu DING Fang College of Mechanical Engineering and Applied Electronics technology,beijing {2. of technology,advanced manufacturing technology,The key laboratory of beijing Municipality,beijing 10002.,china, College of Mechanical Engineering and Applied Electronics technology Beijing University of TechnologyAdvanced Manufacturing TechnologyThe Key Laboratory of Beijing MunicipalityBeijing 100022China

The early impulse fault diagnosis of the gearbox in rolling mills is often difficult and labour intensive because the gearbox of that high speed machine is multi-shafting transmission system,in which many gearsets and rolling bears work together at the same time and there are much complex frequency structure and various disturb.A new time-frequency method based on the wavelet packets technique was developed and used to extract the impact feature from signals collected from faulty data of one rolling mills *** method improves the signal to noise ration so that results obtained using this method represents features with fine resolution in both low-frequency and the high frequency *** results of analysis indicate the validity and the practicability of the method proposed here.

关键词： fault diagnosis feature extraction rolling mills gearbox wavelet packets

Spatio-temporal pattern analysis of single-trial EEG signals recorded during visual object recognition

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Science china(Information Sciences) 2011年第12期54卷 2519-2527页

作者： WANG ChangMing 1 , HU XiaoPing 3 , YAO Li 1,2., XIONG Shi 2.& ZHANG JiaCai 2.1 National key laboratory of Cognitive Neuroscience and Learning, {2. Normal university, {2. 100875, china 2.College of Information Science and technology, {2. Normal university, {2. 100875, china 3 Biomedical Imaging technology Center, Emory university/Georgia Institute of technology, Atlanta 3032., USA 1. National key laboratory of Cognitive Neuroscience and Learning Beijing Normal University Beijing 100875 China3. Biomedical Imaging Technology Center Emory University/Georgia Institute of Technology Atlanta 30322 USA2. College of Information Science and Technology Beijing Normal University Beijing 100875 China

Object discrimination is a fundamental cognitive function for human brains. In this study, we utilized an analysis approach for single-trial electroencephalography (EEG) to analyze the spatio-temporal activation patterns of visual objects processing in human brains, and attempted to apply it to discriminate different visual objects. The spatial patterns were respectively extracted from scalp EEG and the reconstructed cortical sources, while the experiment participants were perceiving 4 different categories of visual objects (faces, buildings, cats and cars). By classifying the patterns extracted from single-trial EEG, the presented visual objects could be discriminated by a computer, and the classification accuracies may provide a quantitative index to evaluate the spatial differences of the brain activations related to different visual objects. Our results demonstrated that the spatial patterns on both the scalp and the sources levels resulted in higher classification accuracies than chance rate. We also examined the classification results using temporally non-overlapping time intervals of different event-related potential (ERP) components. The temporal changes of classification accuracies may reflect the temporal distribution of the discriminative information in the EEG responses. The present pattern extraction and classification methods may compose a computational model for single-trial EEG data analysis in investigations of the spatio-temporal activation patterns for object recognition. These spatio-temporal patterns in EEG may be useful to identifying the discriminative spatial areas and time stages to improve the accuracies and efficiencies of object discrimination. In addition, investigating and utilizing humans'cognitive mechanisms of object recognition may improve computers' processing efficiency of visual information.

关键词： EEG spatio-temporal pattern object recognition single-trial analysis visual information processing

Synthesis and Characterization of Radiate MgO Whiskers

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稀有金属材料与工程 2006年第S3期 648-649页

作者： Yanli Gong~1 Jianbao Li~1 Hong Lin~1 Xiaozhan Yang~1 Xuguang Tong~1 Xiangdong Huang~2.(1.State key laboratory of New Ceramics and Fine {2.,Department of materials Science and Engineering,tsinghua university,beijing 100084,china) (2.Department of materials Science and Engineering,Fuzhou university,Fuzhou 350002.china)

In this paper,radiate MgO whiskers were fabricated in the system of Mg-B-NaCl-Ar at relatively low temperature. The Mg vapor reacted with trace O2.ontained in the reaction system and formed MgO *** appropriate conditions,the MgO vapor could reach supersaturation and grow into highly radiate *** were characterized by means of field emission scanning electronic microscopy （FE-SEM）,transmission electronic microscopy （TEM） and energy dispersive spectrometer （EDS）.The mechanism of the morphologies of MgO was discussed.

关键词： MgO whiskers Synthesis

Modelling of Fluid Flow and Centerline Segregation in Continuous Thin Slab Casting With LES Method

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Modelling of Fluid Flow and Centerline Segregation in Contin...

Research on the Comprehensive Demodulation of Gear Tooth Crack Early Fault

2.06年薄板坯连铸连轧国际研讨会

作者： ZHANG Huan-xin SHEN Hou-fa LIU Bai-cheng (key laboratory for {2. manufacturing by materials processing technology Department of Mechanical Engineering tsinghua university beijing 100084 china)

A continuous casting process analysis program Visual Cast is developed to study the meniscus wave, fluid flow and centerline segregation with large eddies turbulence model and SIMPLER algorithm. It is

关键词： meniscus profile fluid flow centerline segregation thin slab casting continuous casting

来源： cnki会议评论

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武汉理工大学学报 2006年第S2期28卷 596-599页

作者： CUI Lingli DING Fang GAO Lixin ZHANG Jianyu (College of Mechanical Engineering and Applied Electronics technology,beijing {2. of technology,advanced manufacturing technology,The key laboratory of beijing Municipality,beijing 10002.,china College of Mechanical Engineering and Applied Electronics technology Beijing University of TechnologyAdvanced Manufacturing TechnologyThe Key Laboratory of Beijing MunicipalityBeijing 100022China

The component of gear vibration signal is very complex,when a localized tooth defect such as a tooth crack is pre- sent,the engagement of the cracked tooth will induce an impulsive change with comparatively low energy to the gear mesh signal and the background *** paper presents a new comprehensive demodulation method which combined with amplitude envelop demodulation and phase demodulation to extract gear crack early fault.A mathematical model of gear vibration signal contain crack fault is put *** results based on this model show that the new comprehensive demodulation method is more effective in finding fault and judging fault level then conventional single amplitude demodulation at present.

关键词： demodulation gear tooth crack early fault amplitude modulation phase modulation