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A New Boundary of the Mapping Class Group

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Acta Mathematica Sinica,English Series 2023年第5期39卷 885-903页

作者： Li Xin LIU yao zhong SHI School of Mathematics Sun Yat-sen UniversityGuangzhou 510275P.R.China

Based on the action of the mapping class group on the space of measured foliations,we construct a new boundary of the mapping class group and study the structure of this *** an application,for any point in Teichmüller space,we consider the orbit of this point under the action of the mapping class group and describe the closure of this orbit in the Thurston compactification and the Gardiner-Masur compactification of Teichmüller *** also construct some new points in the Gardiner-Masur boundary of Teichmüller space.

关键词： Mapping class group measured foliation Teichmiller space

Road model prediction based unstructured road detection

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Journal of Zhejiang University-Science C(Computers and Electronics) 2013年第11期14卷 822-834页

作者： Wen-hui ZUO Tuo-zhong yao Department of Information Science and Electronic Engineering Zhejiang University Ningbo Institute of Materials Technology&Engineering Chinese Academy of Sciences

Vision-based road detection is an important research topic in different areas of computer vision such as the autonomous navigation of mobile *** outdoor unstructured environments such as villages and deserts,the roads are usually not well-paved and have variant colors or texture *** region- or edge-based approaches,however,are effective only in specific environments,and most of them have weak adaptability to varying road types and *** this paper we describe a novel top-down based hybrid algorithm which properly combines both region and edge cues from the *** main difference between our proposed algorithm and previous ones is that,before road detection,an off-line scene classifier is efficiently learned by both low- and high-level image cues to predict the unstructured road *** scene classification can be considered a decision process which guides the selection of the optimal solution from region- or edge-based approaches to detect the ***,a temporal smoothing mechanism is incorporated,which further makes both model prediction and region classification more *** results demonstrate that compared with traditional region- and edge-based algorithms,our algorithm is more robust in detecting the road areas with diverse road types and varying appearances in unstructured conditions.

关键词： Road detection Surface layout Road model prediction Temporal smoothing

Influences of Temperature and Coal Particle Size on the Flash Pyrolysis of Coal in a Fast-entrained Bed

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Chemical Research in Chinese Universities 2006年第1期22卷 103-110页

作者： CUI Li-jie LIN Wei-gang yao Jian-zhong Multi-phase Reaction Laboratory Institute of Process Engineering Chinese Academy of Sciences Bering 100080 P. R. China Graduate School Chinese Academy of Sciences Beijing 100080 P. R. China

The experiments on the flash pyrolysis of a lignite were carried out in a fast-entrained bed reactor as a basic study on a so-called ＇ coal topping process＇. The investigation focused on the effects of pyrolysis temperature and coal particle size on the product distribution and composition. The experimental results show that an increase in the pyrolysis temperature results in a higher yield of gaseous products while a larger particle size leads to a decrease of the liquid yield. An optimum temperature for the liquid yield was found to be 650℃. A certain amount of phenol groups was found in the liquid products, which may be used to produce high-valued fine chemicals. The FTIR analyses of the coal and chars show that aliphatic structures in the chars are gradually replaced by aromatic structures with the increasing of pyrolysis temperature and coal particle size. The results of this study provide fundamental data and optimal conditions to maximize light oils yields for the coal topping process.

关键词： Fluidized Bed Coal Flash pyrolysis Particle Size Temperature

Controllable Preparation of Plasmonic Gold Nanostars for Enhanced Photothermal and SERS Effects

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Chemical Research in Chinese Universities 2020年第6期36卷 1284-1291页

作者： YU Xinyue zhong yao SUN Yu CHEN Yanwei Key Laboratory of UV-Emitting Materials and Technology of Ministry of EducationNational Demonstration Center for Experimental Physics EducationSchool of PhysicsNortheast Normal UniversityChangchun 130024P.R.China

Gold nanostars(Au NSs)are asymmetric anisotropic nanomaterials with sharp edge *** a promising branched nanomaterial,Au NS has excellent plasmonic absorption and scattering *** order to tune the plasmonic photothermal and surface-enhanced Raman scattering(SERS)activity of Au NSs to obtain the desired characteristics,the ffects of reagents on the local surface plasmon resonance(LSPR)bands of Au NSs were studied and the morphology and size were *** with different sharp edges were synthesized to make their local plasmon resonance mode tunable in the visible and near-infrared *** effects of the number and sharpness of different tips under the control of AgNO3 on the photothermal response of Au NSs and the SERS ac-tivity and their mechanism were discussed in *** results show that as the length of the branch tip becomes longer and the sharpness increases,the plasmonic photothermal effect of Au NSs is strengthened,and the photother-mal conversion efficiency is the highest up to 40%when the length of Au NSs is the *** NSs with high SERS activity are used for the Raman detection *** on this property,the quantitative detection of the pesticide thiram is achieved.

关键词： Gold nanostar Controlled growth Photothermal effect Surface-enhanced Raman scattering(SERS)activity

Robust water hazard detection for autonomous off-road navigation

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第6期10卷 786-793页

作者： Tuo-zhong yao Zhi-yu XIANG Ji-lin LIU Department of Information Science and Electronic Engineering Zhejiang University Hangzhou 310027 China

Existing water hazard detection methods usually fail when the features of water surfaces are greatly changed by the surroundings, e.g., by a change in illumination. This paper proposes a novel algorithm to robustly detect different kinds of water hazards for autonomous navigation. Our algorithm combines traditional machine learning and image segmentation and uses only digital cameras, which are usually affordable, as the visual sensors. Active learning is used for automatically dealing with problems caused by the selection, labeling and classification of large numbers of training sets. Mean-shift based image segmentation is used to refine the final classification. Our experimental results show that our new algorithm can accurately detect not only ‘common’ water hazards, which usually have the features of both high brightness and low texture, but also ‘special’ water hazards that may have lots of ripples or low brightness.

关键词： Water hazard detection Active leaming Adaboost Mean-shift

Mathematical model of wave transformation over radial sand ridge field on continental shelf of South Yellow Sea

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Water Science and Engineering 2010年第1期3卷 36-46页

作者： yao-zhong YANG Wei-bing FENG College of Harbor Coastal and Offshore Engineering Hohai University Nanjing 210098 P. R. China

According to a deformed mild-slope equation derived by Guang-wen Hong and an enhanced numerical method, a wave refraction-diffraction nonlinear mathematical model that takes tidal level change and the high-order bathymetry factor into account has been developed. The deformed mild-slope equation is used to eliminate the restriction of wave length on calculation steps. Using the hard disk to record data during the calculation process, the enhanced numerical method can save computer memory space to a certain extent, so that a large-scale sea area can be calculated with high-resolution grids. This model was applied to wave field integral calculation over a radial sand ridge field in the South Yellow Sea. The results demonstrate some features of the wave field：（1） the wave-height contour lines are arc-shaped near the shore; （2） waves break many times when they propagate toward the shore; （3） wave field characteristics on the northern and southern sides of Huangshayang are different; and （4） the characteristics of wave distribution match the terrain features. The application of this model in the region of the radial sand ridge field suggests that it is a feasible way to analyze wave refraction-diffraction effects under natural sea conditions.

关键词： wave transformation mathematical model radial sand ridge field South Yellow Sea

Compound Ceramic Coatings Grown by Micro-plasma Oxidation on Ti-6Al-4V Alloy

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Chinese Journal of Aeronautics 2006年第B12期19卷 126-129页

作者： XUE Wei yao zhong-ping JIANG Zhao-hua Department of Applied Chemistry Harbin Institute of Technology Harbin 150001 China Heilongjiang Provincial Institute of Measurement and Verification Harbin 150036 China

Compound ceramics coatings on the Ti-6Al-4V alloy were prepared by the direct current micro-plasma oxidation （MPO） in NaAlO2 solution. The composition and morphology of the coatings were studied with the X-ray diffraction （XRD） and the scanning electron microscopy （SEM）, respectively. Inductively coupled plasma atomic emission spectrometer technique was used to analyze the solution features of Ti-6Al-4V alloy in the process of preparation. The results reveal that Al2TiO5 forms in the coatings at the initial stages of MPO reaction, and its content changes rapidly with the reaction continuing： after 20 min, the ceramics coatings are composed of α-Al2O3, 7-Al2O3 and Al2TiO5, but after 40 min, its main composition is of α-Al2O3. The content of Ti in the solution will increase when the MPO time extends, and as will Al in the anode area until, after 30 min, it reaches the maximum and keeps constant from then on. Both substrata of Ti and Al in the electrolyte join the MPO reaction at the initial stage, where the formation of Al2TiO5 happens; but as the MPO reaction prolongs, more and more Al in the electrolyte will take part in the reaction, leading to the appearance of a large amount ofAl2O3.

关键词： micro-plasma oxidation ceramic coatings composition inductively coupled plasma atomic emission spectrometer technique (ICP-AES)

Classification Method for Mechanical Defects in GIS Equipment Based on Mode Function Analysis and Improved Relevance Vector Machines

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CSEE Journal of Power and Energy Systems 2023年第2期9卷 790-801页

作者： yao zhong Jian Hao Xupeng Wang Ruijin Liao Ruilei Gong Yilin Ding State Key Laboratory of Power Transmission Equipment&System Security and New Technology University of ChongqingChongqing 400044China Shandong Taikai High Voltage Swichgear Co.Ltd. Taian 271000China

Mechanical defects,in gas-insulated switchgear(GIS)equipment,have weak response characteristics,leading to significant difficulties in the classification of ***,this paper proposes a novel mechanical defect feature extraction and classification method that combines independent intrinsic mode function(IIMF)analysis and an improved multikernel mapping fast multi-classification relevance vector machine(MKF-mRVM).Enlightened by the differences in the GIS operating vibration mode,the IIMF series were first obtained based on regenerated phase-shifted sinusoid-assisted empirical mode decomposition(RPSEMD)and modal *** singular value decomposition and time-frequency conversions were performed to construct combined feature ***,multikernel mapping and domain sampling were introduced to improve the calculation speed and recognition accuracy of the mRVM,which was more suitable for on-line *** show that the proposed RPSEMD-MKF-mRVM model achieves a faster training speed(14.23 s)and higher accuracy(98.21%)than other algorithms,and it can adapt to variable loads.

关键词： GIS IIMF analysis mechanical defect MKFmRVM RPSEMD

实时直接分析质谱及与样品前处理技术联用的研究进展

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分析测试学报 2025年第1期44卷 43-50页

作者：林雪维姚钟平香港理工大学化学生物学及药物研发国家重点实验室未来食品研究院中医药创新研究中心应用生物与化学科技学系香港理工大学深圳研究院深圳市中药药学及分子药理学研究重点实验室深圳市食品生物污染与控制重点实验室

实时直接分析质谱无需或者仅需简单的样品制备，即能对样品进行原位电离及直接快速的进样分析，已被广泛运用于食品、司法科学、药物分析、临床科学、环境等领域。尽管已有不少文献报道DARTMS的定量结果与液相/气相色谱-质谱相当，但其... 详细信息

实时直接分析质谱无需或者仅需简单的样品制备，即能对样品进行原位电离及直接快速的进样分析，已被广泛运用于食品、司法科学、药物分析、临床科学、环境等领域。尽管已有不少文献报道DARTMS的定量结果与液相/气相色谱-质谱相当，但其痕量分析物的检测性能仍是关键问题。为获得更准确的定量结果，研究人员开发出了一系列样品前处理技术与DART-MS联用。该文从DART-MS的原理出发，对其不同研究领域中无需样品前处理的应用进行了综述，并进一步介绍了样品预处理技术（如固相萃取、固相微萃取、顶空固相网增强吸附、分散固相萃取、分散磁性固相萃取、机械化学萃取、微波辅助萃取和热解吸）与DART-MS联用的研究成果。该综述旨在对DART-MS的样品直接分析的应用及样品前处理技术的开发提供帮助。

关键词：质谱实时直接分析直接样品分析样品预处理