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Feature Selection by Merging Sequential Bidirectional Search into Relevance Vector Machine in Condition Monitoring

Chinese Journal of Mechanical Engineering 2015年第6期28卷 1248-1253页

作者： ZHANG Kui dong yu BALL Andrew School of Economics & Management Wuhan Polytechnic University School of Information Engineering Communication University of China School of Computing & Engineering University of Huddersfield

For more accurate fault detection and diagnosis, there is an increasing trend to use a large number of sensors and to collect data at high frequency. This inevitably produces large-scale data and causes difficulties in fault classification. Actually, the classification methods are simply intractable when applied to high-dimensional condition monitoring data. In order to solve the problem, engineers have to resort to complicated feature extraction methods to reduce the dimensionality of data. However, the features transformed by the methods cannot be understood by the engineers due to a loss of the original engineering meaning. In this paper, other forms of dimensionality reduction technique（feature selection methods） are employed to identify machinery condition, based only on frequency spectrum data. Feature selection methods are usually divided into three main types： filter, wrapper and embedded methods. Most studies are mainly focused on the first two types, whilst the development and application of the embedded feature selection methods are very limited. This paper attempts to explore a novel embedded method. The method is formed by merging a sequential bidirectional search algorithm into scale parameters tuning within a kernel function in the relevance vector machine. To demonstrate the potential for applying the method to machinery fault diagnosis, the method is implemented to rolling bearing experimental data. The results obtained by using the method are consistent with the theoretical interpretation, proving that this algorithm has important engineering significance in revealing the correlation between the faults and relevant frequency features. The proposed method is a theoretical extension of relevance vector machine, and provides an effective solution to detect the fault-related frequency components with high efficiency.

关键词： feature selection relevance vector machine sequential bidirectional search fault diagnosis

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Non-Fourier heat conduction in a thin gold film heated by an ultra-fast-laser

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Science China(Technological Sciences) 2015年第4期58卷 638-649页

作者： MAO yu dong XU Ming Tian Department of Engineering Mechanics School of Civil Engineering Shandong University School of Energy and Power Engineering Shandong University

Based on the dual-phase-lagging(DPL)heat conduction model,the Cattaneo-Vernotte(CV)model and the improved CV model we investigate the one-dimensional heat conduction in gold films with nano-scale thickness exposed to an ultra-fast laser *** influence of system parameters on the temperature field is *** find that for all the non-Fourier heat conduction models considered in this work,a larger Knudsen number normally leads to a higher *** the DPL model,the large ratio of the phase lag of temperature gradient to the phase lag of heat flux reduces the maximum temperature and shortens the time for the system to reach its steady *** CV model and the improved CV model lead to the similar thermal wave behavior of the temperature field,but the thermal wave speeds for these two models are different,especially for large Knudsen *** the phase lag of temperature gradient is smaller,the difference between the DPL model and the improved CV model is not significant,but for the large phase lag of temperature gradient the difference becomes quite significant,especially for the large Knudsen *** addition,the effect of the surface accommodation coefficient,which is a parameter in the slip boundary condition,on the temperature field of the gold film heated by ultra-fast laser pulses is investigated based on the DPL model.

关键词： Nano-scale heat conduction ultrafast laser heating thin film Knudsen number

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Clonal Plasticity in Response to Reciprocal Patchiness of Light and Nutrients in the Stoloniferous Herb Glechoma Iongituba L.

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Journal of Integrative Plant Biology 2006年第4期48卷 400-408页

作者： yu Chu Fei-Hai yu Ming dong Laboratory of Quantitative Vegetation Ecology Institute of Botany the Chinese Academy of Sciences Beijing 100093 China

Interconnected ramets of clonal plants can functionally specialize in the uptake of resources from aboveground and/or underground sources. Ramet pairs of the clonal stoloniferous herb Glechoma Iongltuba L. were grown In spatially heterogeneous environments with complementary availability of light and nutrients. Plasticity with respect to root-shoot ratio, fitness-related traits （biomass, number of ramets and dry weight per ramet）, morphological traits （lamina area, root length） were experimentally examined. The aim was to understand the adaptation of G. Iongltuba to an environment with reciprocal patchiness of light and soil nutrients by plasticity In Its root-shoot ratio and clonal morphology. The results showed that the performance of ramets growing In patches with high light Intensity and low soil nutrients into the adjacent opposite patches was Increased in terms of fitness-related traits. However, the performance of those from patches with low light Intensity and high soil nutrients into the adjacent opposite patches was not changed. The root-shoot ratio and clonal morphology were plastic. Morphological traits such as lamina area and root length were altered In a way that enhanced the capture of light resources and soil nutrients. Apparent reciprocal resource transport between the ramets In an environment of reciprocal patchiness of resources can enhance the growth of ramets with complementary resource deficiencies.

关键词： clonal plant clonal plasticity complementary patchiness functional specialization light soil nutrients.

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Controllable Synthesis of CaCO_3 Micro/Nanocrystals with Different Morphologies in Microemulsion

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Chemical Research in Chinese Universities 2010年第5期26卷 678-682页

作者： yu dong CHU Ying dong Li-hong ZHUO yu-jiang Department of Chemistry Northeast Normal University Changchun 130024 P. R. China Elementary Normal College Dalian University Dalian 116300 P. R. China

Lens-like vaterite CaCO3 microrings composed of CaCO3 nanoparticles were synthesized via a microemulsion-mediated route at room temperature with ethanol and n-hexanol as co-surfactant. This process did not demand any additional energy such as heating or continuous agitation. It was the first time to use ethanol as co-surfactant in the synthesis of micro or nanomaterials. And the ethanol was believed to play an important role in the aggregation fashion of CaCO3 nanoparticles. Moreover, shuttle-shaped nanorods, hexagonal nanoplates, and rice-like nanoparticles were also fabricated by modulating the growth parameters. Additionally, the introduce of ethanol into microemulsions as co-surfactant may be generalized as a novel green route to control the structure of other functional materials.

关键词： CaCO3 Microring Cosurfactant

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Electromagnetic Properties of S11 States in a Light Cone Quark Model

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Communications in Theoretical Physics 2006年第2X期46卷 269-274页

作者： HE Jun dong yu-Bing Institute of High Energy Physics the Chinese Academy of Sciences P.O. Box 918-4 Beijing 100049 China Graduate School of the Chinese Academy of Sciences Beijing 100049 China

Using relativistic spin-flavor wave functions of a Lorentz-covariant light cone quark model, we calculate the electromagnetic form factors of two S11 resonances, N（1535） and N（1650）, and the helicity amplitudes A1/2 and S1/2 for electroexcitation of the S11 resonances from the nucleon. The electromagnetic form factors of these S11 resonances are found to be similar to those of the nucleon in shape, while the charge form factor of neutral N（1650） is nearly zero. The relative peak height of the S11 charge form factors is controlled by the mixing angle common to both resonance wave functions. As in most quark models, there is a systematic overestimate of A1/2 in both N（1535） and N（1650） cases at the photon point. A sizeable S1/2 for all cases is produced as suggested by experiments.

关键词： electromagntic properties S11 states light cone quark model

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ρ meson impact parameter distributions

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Chinese Physics C 2018年第6期42卷 37-43页

作者： Bao-dong Sun yu-Bing dong Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China School of Physics University of Chinese Academy of Sciences Beijing 100049 China Theoretical Physics Center for Science Facilities （TPCSF） CAS Beijing 100049 China

In this paper, the p meson impact parameter dependent parton distributions and the impact parameter dependent form factors are introduced and discussed. By employing a Gaussian form wave packet, we calculate the impac... 详细信息

关键词： ρ meson impact parameter distribution light-cone approach

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Effect of solution treatment on microstructure and mechanical properties of as-cast Al-12Si-4Cu-2Ni-0.8Mg-0.2Gd alloy

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China Foundry 2022年第3期19卷 238-244页

作者： yu-dong Sui Ye-hua Jiang Qu-dong Wang School of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China National Engineering Research Center of Light Alloys Net Forming and State Key Laboratory of Metal Matrix Composite Shanghai Jiao Tong UniversityShanghai 200240China

Effect of solution treatment on microstructure and mechanical properties of Al-12Si-4Cu-2Ni-0.8Mg-0.2Gd alloy was *** show the Si particles become stable and more intermetallic compounds dissolve in the matrix after solution treatment at 500℃for 2 h followed by 540℃for 3 h(T4).The skeleton-like Al_(3)CuNi develops into two parts in the T4 alloy:one is Al_(3)CuNi which has the framework shape;the other is intermetallics including the Al_(3)CuNi(size:5-10μm)and AlSiCuNiGd phases(size:≤5μm)with complex *** 0.2%Gd can improve the mechanical properties of the alloys after two-step solution treatment(500℃/2 h followed by 540℃/3 h),the hardness of the alloy increases from 130.9 HV to 135.8 HV compared with the alloy with one-step solution treatment(500℃/2 h),the engineering strength increases from 335.45 MPa to 352.03 MPa and the fracture engineering strain increases from 1.44%to 1.67%.

关键词： Al-Si-Cu-Ni-Mg alloy Gd element solution treatment microstructure mechanical properties

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Synthesis and characterization of super paramagnetic composite photocatalyst-Titania/silica/nickel ferrite

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Particuology 2011年第5期9卷 475-479页

作者： yu Li Xiufang dong Junping Li School of Chemical Engineering and Environment North University of China Taiyuan 030051 Shanxi China

Composite photocatalysts with TiO2 porous shell and magnetic core were synthesized by using NiFe2O4 as a magnetic core, SiO2 as an intermediate layer and polyethylene glycol with molecular weight of 1000 （PEG 1000） as a template direction agent. The samples were characterized with N2 adsorption-desorption, X-ray diffraction （XRD）, transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, vibrating sample magnetometry （VSM） and ultraviolet-visible （UV-vis） spectroscopy. The results showed that the obtained composites are spherical particles about 50 nm in diameter. The mesoporous TiO2 with magnetic core calcined at 350 ℃, 450 ℃, and 550 ℃ was found to have, respectively, different specific surface areas （94, 86, and 68 m^2/g） and average pore sizes （1.4, 2.2, and 2.8 nm）. The photocatalytic activity was investigated for degradation of nitrobenzene under UV irradiation. Nitrobenzene was decomposed in 300 min under irradiation of an 8 W UV lamp with a peak wavelength of 253.7 nm. The composite nanoparticles exhibited high photocatalytic efficiency and super paramagnetic nature for cleaning polluted water by magnetic separation.

关键词： Titania Mesoporous Photocatalyst Core-shell

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Characterization of intraocular pressure pattern and changes of retinal ganglion cells in DBA2J glaucoma mice

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International Journal of Ophthalmology(English edition) 2016年第2期9卷 211-217页

作者： Jing Wang yu dong Cullen Eye Institute Baylor College of Medicine

AIM： To characterize the pattern of intraocular pressure （lOP） change and the deficit of retinal ganglion cells （RGCs） in DBA2J, which is most well-characterized chronic glaucoma mouse model and wild type （WT） C57bl/6 mice, and to study the relationship between lOP change and RGCs deficit. METHODS： lOP was monitored with a rebound tonometer in C57bl/6 and DBA2J mice from 3 to 15-month-old. Retinal function was evaluated by dark -adapted electroretinogram （ERG） in DBA2J and WT mice of 15-month-old. A dye （Neurobiotin） was applied to optic nerve stump to retrograde label RGCs. TO-PRO-3 visualized all nuclei of cells in the RGC layer. RESULTS： The lOP in WT mice was 9.03-0.6 mm Hg on average and did not increase significantly as aging. The lOP in DBA2J mice, arranging from 7.2 to 28 mm Hg, was increasing significantly as aging, and it was normal at 3-month--old compared with WT mice, slightly increased from 7-month-old and increased in 50% animals at 11-month-old and in 38% animals at 15-month-old. The RGCs density in DBA2J mice started reducing by 7-month-old, continuously decreased until reached about 20% of RGC in WT retina by 15-month-old. RGC density was not linearly correlated with lOP in 15-month- old DBA2J mice. The amplitude of positive scotopic threshold response, and negative scotopic threshold response of ERG were significantly reduced in DBA2J mice of 15-month-old than that in age-paired WT mice. CONCLUSION： The present study found that DBA2J mice display pathological and functional deficits of the retina that was not linearly correlated with lOP.

关键词： retinal ganglion cell glaucoma intraocularpressure retina mouse

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Flexible impedance sensor based on Ti_(3)C_(2)T_(x)MXene and graphitic carbon nitride nanohybrid for humidity-sensing application with ultrahigh response

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Rare Metals 2023年第7期42卷 2204-2213页

作者： Yang Lu Meng-yu Wang dong-yue Wang yue-Hang Sun Zi-Hao Liu Rong-Ke Gao Lian-dong yu dong-Zhi Zhang College of Control Science and Engineering China University of Petroleum(East China)Qingdao266580China

This paper reported the impedance-type humidity sensor based on Ti_(3)C_(2)T_(x)/g-C_(3)N_(4)nanomaterials which was fabricated on a flexible polyethylene terephthalate(PET)*** scanning electron microscopy(SEM),X-ray diffraction(XRD),and X-ray photoelectron spectroscopy(XPS)measurements were used to demonstrate the successful synthesis and combination of Ti_(3)C_(2)T_(x)and g-C_(3)N_(4)*** performance of the humidity sensor was tested at room *** experimental results showed that the Ti_(3)C_(2)T_(x)nanosheets with g-C_(3)N_(4)nanosheets endowed the humidity sensor with an ultra-high response,rapid response/recovery time,and negligible *** complex impedance spectroscopy(CIS)and bode diagrams were used to further analyze the sensing mechanism of the Ti_(3)C_(2)T_(x)/g-C_(3)N_(4)humidity *** Ti_(3)C_(2)T_(x)/g-C_(3)N_(4)humidity sensor can monitor skin humidity and high-humidity alarm,which demonstrates great potential applications in various fields.

关键词： Ti_(3)C_(2)T_(x)MXene Graphitic carbon nitride Flexible humidity sensor Humidity detection Alarm application

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