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

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, Beijing Normal university, Beijing 100875, china 2.College of Information Science and Technology, Beijing Normal university, Beijing 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

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Alkali-silica Reactivity of Different Aggregates from Mineral and Textural Characteristics

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Journal of Wuhan university of Technology(Materials Science) 2008年第6期23卷 901-906页

作者：莫祥银 analysis and testing {2. & Jiangsu Key Laboratory of Biofunctional Materials Nanjing Normal University

To identify the aggregates causing the alkali-silica reaction, and the reactivity of rocks in different parts of china, the mineral and texture characteristics of some typical coarse ag gregates and the alkali reactivity of these aggregates were systematically investigated. On one hand, petrographic examination of aggregates, combined with X-ray diffraction analysis, chemical analysis, scanning electron microscopy, was conducted for analyzing their mineralogy and texture. It was found that not only mineral characteristics, but also their interior structure would affect their potential alkali-silica reactivity. Furthermore, the alkali-silica reactivity of aggregates is due to their mineral compositions, such as containing different alkali-reactive minerals, while, different stuctures of those aggregates with similar minerals affect their reactivity to some extent. There are some amount of micro-aperture and cracks across the quartz in the aggregate, which may become the natural accesses for Na^＋, K^＋, and OH^- ions to intrude in the mortar or concrete during the process of alkali-silica reaction. Alkali-silica reactivity of the aggregates was detected by the accelerated mortar bars test. It was revealed that all the aggregates tested were alkali-silica reactive and the results were also in accordance with their mineral and structure analysis.

关键词： petrographic examination of aggregates study of thin sections x-ray diffraction analysis chemical analysis scanning electron microscopy

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Application analysis of empirical mode decomposition and phase space reconstruction in dam time-varying characteristic

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Science china(Technological Sciences) 2010年第6期53卷 1711-1716页

作者： ZHANG ZhiJun1,2.3,GU ChongShi1,2.BAO TengFei1,2.ZHANG Lan1,2.& YU Hong1,2.1 State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Hohai university,Nanjing 2.0098,china 2.National Engineering Research {2. of Water Resources Efficient Utilization and Engineering Safety,Hohai university,Nanjing 2.0098,china 3 Department of Civil,Environmental and Geomatic Engineering,Swiss Federal Institute of Technology,Zurich 8093,Switzerland 1. State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University Nanjing 210098 China2. National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety Hohai University Nanjing 210098 China3. Department of Civil Environmental and Geomatic Engineering Swiss Federal Institute of Technology Zurich 8093 Switzerland

In view of some courses of the time-varying characteristics processing in the analysis of dam deformation,the paper proposes a new method to analyze the dam time-varying characteristic based on the empirical mode decomposition and phase space reconstruction *** of all,to reduce the influences on the traditional statistical model from human factors and assure the analysis accuracy,response variables of the time-varying characteristic are obtained by the way of the empirical mode decomposition;and then,a phase plane of those variables is reconstructed to investigate their processing *** methods have already been applied to an actual project and the results showed that data interpretation with the assists of empirical mode decomposition and phase space reconstruction is effective in analyzing the perturbations of response variables,explicit in reflecting the entire development process,and valid for obtaining the evolution rules of the time-varying *** methodology is a powerful technical support for people to further master the rules of dam operation.

关键词： dam safety monitoring dam time-varying characteristic empirical mode decomposition phase space reconstruction

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Dynamics analysis and experiment on the fishtailing type of valveless piezoelectric pump with rectangular vibrator

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Science china(Technological Sciences) 2010年第12期53卷 3241-3247页

作者： HUANG Yi1, ZHANG JianHui1, HU XiaoQi1, XIA QiXiao2. HUANG WeiQing1 & ZHAO ChunSheng1 1 Department of Aerospace Engineering, Nanjing university of Aeronautics and Astronautics, Nanjing 2.0016, china 2.Department of Mechanical and Electrical Engineering, Beijing {2. university, Beijing 10002., china 1. Department of Aerospace Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China2. Department of Mechanical and Electrical Engineering Beijing Union University Beijing 100020 China

In recent years, the research and development of piezoelectric pumps have become an increasingly popular topic. Minimization, structure simplification and stronger output become the focus of piezoelectric pumps’ research due to its possible application in MEMS technology. The valveless fishtailing piezoelectric pump, neither a volumetric nor a rotating pump, was invented according to the bionics of fish swimming. With assumption that the head of the fish is fixed while its tail is swinging, fluid would flow toward the end of the tail, achieving the function of a valveless pump. This type of pumps creates a new branch for the piezoelectric pump research, which is proposed for the first time in this paper. The relationship between the flow rates and vibrating frequencies was derived from the interaction between the vibrator and fluid. Numerical simulations with FEM software were conducted to study the first and second vibration modes of the piezoelectric vibrator. The results showed that the maximum amplitude of the vibrator was 0.9 mm at the frequency of 76 Hz for the first vibration mode, while the maximum amplitude of the vibrator was 0.2. mm at the frequency of 781 Hz for the second vibration mode. Experiments were conducted with the Doppler laser vibration measurement system, and the results were compared to those of the FEM simulation. It was shown that in the first vibration mode the piezoelectric vibrator reached its maximum amplitude of about 0.9 mm at the driving frequency of 49 Hz, which gives the flow rate of 2.0 mL/min, in the second vibration mode, the maximum amplitude was about 0.2. mm at the frequency of 460 Hz with the flow rate being 6.4 mL/min.

关键词： piezoelectric pump valveless fishtailing rectangular vibrator dynamics analysis experiment

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Orientation-Singularity Representation and Orientation-Capability Computation of a Special Class of the Gough-Stewart Parallel Mechanisms Using Unit Quaternion

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Chinese Journal of Mechanical Engineering 2012年第6期25卷 1096-1104页

作者： LI Baokun1, 2. CAO Yi1, 3, *, ZHANG Qiuju1, and HUANG Zhen4 1 School of Mechanical Engineering, Jiangnan university, Wuxi 2.412., china 2.School of Mechanical Engineering, Anhui university of Science and Technology, Huainan 2.2.01, china 3 State Key Laboratory of Fluid Power Transmission and Control, Hangzhou 31002., china 4 Robotics Research center, Yanshan university, Qinhuangdao 066004, china 1. School of Mechanical Engineering Jiangnan University Wuxi 214122 China 2. School of Mechanical Engineering Anhui University of Science and Technology Huainan 232001 China 3. State Key Laboratory of Fluid Power Transmission and Control Hangzhou 310027 China 4. Robotics Research center Yanshan University Qinhuangdao 066004 China

Singular configuration seriously affects the performance of the Gough-Stewart parallel mechanism and has attracted many researchers’ attentions. However, most of existing topics often focus on the position-singularity of the mechanism for a constant-orientation, but few reports research the orientation-singularity for a given position. In order to investigate the orientation-singularity of the Gough-Stewart parallel mechanisms with two dissimilar semi-regular hexagonal platforms for a given position, after constructing the discrimination matrix of the singular configuration of the mechanism and computing the determinant of this matrix by using unit quaternion as the orientation parameters which can avoid the singularities in parameterization, a general symbolic expression representing the three-dimensional orientation-singularity locus for a given position is obtained and the three-dimensional view of the orientation-singularity locus is further described. The orientation-singularity-free void exists inside the orientation-singularity locus, but the shape of the orientation-singularity-free void is irregular and inconvenient for the design of the mechanism. The minimal inscribed sphere of the three-dimensional orientation-singularity locus namely the orientation-singularity-free ball is described. The radius of the ball orientation-capability is used as the measurement for the orientation-singularity-free void size. A new efficient algorithm is proposed for the computation of the orientation-capability. Finally, the influences of the geometry parameters and the different positions of the mechanism on the orientation-capability are discussed. A new method of the singularity analysis of the Gough-Stewart parallel mechanism is advanced based on the unit quaternion, and the research finds have important referential value for the configuration parameters optimization of this class of the parallel mechanisms with the goal of having the maximal singularity-free zone.

关键词： parallel mechanism unit quaternion orientation-singularity orientation-singularity-free void orientation-capability

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Systematic distortion in cosmic microwave background maps

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Science china(Physics,Mechanics & Astronomy) 2009年第5期52卷 804-808页

作者： LIU Hao 1,3 &LI TiPei 1,2.1Key Laboratory of Particle Astrophysics,Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,china 2.1} for Astrophysics,Tsinghua {2.,Beijing 100084,china 3 Graduate {2. of Chinese Academy of Sciences,Beijing 100049,china Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China center for Astrophysics Tsinghua University Beijing 100084 China Graduate university of Chinese Academy of Sciences Beijing 100049 China

To minimize instrumentally the induced systematic errors,cosmic microwave background(CMB)anisotropy experiments measure temperature differences across the sky using pairs of horn antennas, temperature map is recovered from temperature difference obtained in sky survey through a map-making *** inspect and calibrate residual systematic errors in the recovered temperature maps is important as most previous studies of cosmology are based on these *** analyzing pixel-ring coupling and latitude dependence of CMB temperatures,we find notable systematic devia- tion from CMB Gaussianity in released Wilkinson Microwave Anisotropy Probe(WMAP)*** detected deviation cannot be explained by the best-fit LCDM cosmological model at a confidence level above 99%and cannot be ignored for a precision cosmology study.

关键词： cosmology cosmic microwave background methods data analysis

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Three classes of smooth Banach submanifolds in B(E,F)

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Science china Mathematics 2007年第9期50卷 1233-1239页

作者： Ji-pu Ma Tseng Yaun Rong Functional analysis Research center,Harbin Normal {2.,Harbin 15002.,china 1. Tseng Yaun Rong Functional analysis Research center Harbin Normal University Harbin 150025 China

Let E,F be two Banach spaces, and B(E,F), Ф(E,F), SФ(E,F) and R(E,F) be the bounded linear, Fredholm, semi-Frdholm and finite rank operators from E into F, respectively. In this paper, using the continuity characteristics of generalized inverses of operators under small perturbations, we prove the following result: Let Σ be any one of the following sets: {T ∈ Ф(E,F) : IndexT = const. and dim N(T) = const.}, {T ∈ SФ(E,F) : either dim N(T) = const. < ∞ or codim R(T) = const. < ∞} and {T ∈ R(E,F) : RankT =const.< ∞}. Then Σ is a smooth submanifold of B(E,F) with the tangent space T AΣ = {B ∈ B(E,F) : BN(A) ? R(A)} for any A ∈ Σ. The result is available for the further application to Thom’s famous results on the transversility and the study of the infinite dimensional geometry.

关键词： semi-Fredholm operators smooth submanifold transversility generalized inverse 47B38 15A2. 58A05

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Limitation of fault-sealing and its control on hydrocarbon accumulation——An example from the Laoyemiao Oilfi eld of the Nanpu Sag

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Petroleum Science 2008年第4期5卷 295-301页

作者： Jiang Zhenxue Dong Yuexia Li Hongyi Liu Luofu Liu Guangdi Li Xiaoying Basin and Reservoir Research center China University of Petroleum Beijing 102249 China State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum Beijing 102249 China Research Institute of Exploration and Development Jidong Oilfield PetroChina Tangshan Hebei 063004 China School of Resources and Information Technology China University of Petroleum Beijing 102249 China

Based on previous studies on the internal structures of fault belts, the fault belts in the Laoyemiao Oilfield of the Nanpu Sag can be divided into three units, a crushed zone, an upper induced fracture zone and a lower induced fracture zone according to the log response characteristics. The upper induced fracture zone is characterized by the development of pervasive fractures and has a poor sealing or non-sealing capability. It therefore can act as pathways for hydrocarbon migration. The lower induced fracture zone consists of fewer fractures and has limited sealing capability. The crushed zone has a good sealing capability comparable to mudstone and can thus prevent lateral migration of fluid. Through physical modeling and comparing laboratory data with calculated data of oil column heights of traps sealed by faults, it is concluded that the fault-sealing capability for oil and gas is limited. When the oil column height reaches a threshold, oil will spill over from the top of reservoir along the lower induced fracture zone under the action of buoyancy, and the size of reservoir will remain unchanged. analysis of the formation mechanisms of the fault-sealed reservoirs in the Nanpu Sag indicated that the charging sequence of oil and gas in the reservoir was from lower formation to upper formation, with the fault playing an important role in oil and gas accumulation. The hydrocarbon potential in reverse fault-sealed traps is much better than that in the consequent fault-sealed traps. The reverse fault-sealed traps are favorable and preferred exploration targets.

关键词： Limitation of fault-sealing fault belt oil column height hydrocarbon accumulation Nanpu Sag

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Curcumin protects mitochondria from oxidative damage and attenuates apoptosis in cortical neurons

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Acta Pharmacologica Sinica 2004年第12期25卷 40-46页

作者： Yuan-gui ZHU2. Xiao-chun CHEN3, Zhi-zhe CHEN4, Yu-qi ZENG, Guang-bin SHI, Yan-hua SU, Xu PENG Fujian Instituteof Geriatrics, Fujian Institute of Hematology, union Hospital, Fujian Medical university, Fuzhou 350001,{2. 2.ow in Rush university Medical center, Chicago, IL 60612.USA. Fujian Institute of Geriatrics Fujian Institute of Hematology Union Hospital Fujian Medical University Fuzhou 350001 Chin

AIM: To investigate the effect of curcumin on tert-butyl hydroperoxide (t-BHP)-induced oxidative damage in rat cortical neurons and to explore the possible mechanism. METHODS: Primary cultured rat cortical neurons were performed in vitro and cell viability was measured by MTT assay. DNA fragmentation was used to evaluate cell apoptosis. Intracellular reactive oxygen species (ROS) and mitochondrial membrane potential (?Ψm) was deter- mined by flow cytometric assay. Cellular glutathione (GSH) content was measured by spectrophotometer. Bcl-2.family proteins, cytochrome c, cleaved caspase-3, and poly (ADP-ribose) polymerase (PARP) were detected by Western blot. RESULTS: Exposure of tBHP 100 μmol/L to neurons for 60 min resulted in ?Ψm loss and cyto- chrome c release from mitochondria and subsequent activationof caspase-3 and PARP cleavation, and cell apoptosis. After removal of tBHP and then further treatment with curcumin (2.5-2. μmol/L) for 18 h, curcumin abrogated ?Ψm loss and cytochrome c release, blocked activation of caspase3, and altered the expression of Bcl-2.family. Further curcumin treatment also prevented cellular GSH and decreased intracellular ROS generation markedly. Curcumin eventually attenuated tBHP-induced apoptosis in cortical neurons. CONCLUSION: Curcumin may attenuate oxidative damages in cortical neurons by reducing intracellular production of ROS and protecting mito- chondria from oxidative damage.

关键词： Curcumin tert-butyl hydroperoxide apoptosis oxidative stress Bcl-2.family proteins mitochondria Alzheimerdisease

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2.0km/h提速客车径向转向架动力学性能研究

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铁道学报 2004年第1期26卷 22-27页

作者：李芾傅茂海卜继玲西南交通大学牵引动力研究中心四川成都610031 西南交通大学机车车辆研究所四川成都610031

径向转向架是改善机车车辆曲线通过性能的有效途径。简要介绍了国内外径向转向架发展现状 ,阐述了径向转向架的导向机理及基本结构模式。根据自导向径向转向架的基本原理 ,在现有的几种自导向转向架结构的基础上 ,提出了 2.0 0km/h提速... 详细信息

径向转向架是改善机车车辆曲线通过性能的有效途径。简要介绍了国内外径向转向架发展现状 ,阐述了径向转向架的导向机理及基本结构模式。根据自导向径向转向架的基本原理 ,在现有的几种自导向转向架结构的基础上 ,提出了 2.0 0km/h提速客车自导向径向转向架的基本方案 ,建立了动力学仿真模型 ,利用Simpack仿真软件对其进行了动力学性能分析和计算 ,并与常规转向架进行了比较。理论分析和计算结果表明。

关键词：提速动力学径向转向架

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