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Machining Characteristics in Cryogenic Grinding of SiCp/Al Composites

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Acta Metallurgica Sinica(English Letters) 2014年第5期27卷 869-874页

作者： Li Zhou Shutao Huang xiaolin yu School of Mechanical Engineering Shenyang Ligong University

In this study, liquid nitrogen was applied to grind SiCp/Al composites with high volume fraction and large SiC particle at different levels of cutting conditions, and the effects of grinding depth and speed on grinding force, surface morphology, and surface roughness were investigated. At the same time, the effect of cryogenic cooling was also compared with that of conventional wet grinding. The experimental results indicated that cryogenic cooling is effective in enhancing supporting function of Al matrix to the SiC particles and improving surface quality. Additionally, the brittle fracture of SiC particles was suppressed and some ductile streaks on SiC particle could be observed.

关键词： SiCp/Al composites Grinding Cryogenic machining Surface quality

Origins and pathways of the subsurface and intermediate water masses of the Indonesian Throughflow derived from historical and Argo data

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Acta Oceanologica Sinica 2008年第4期27卷 17-25页

作者： ZHANG Yanhui yu xiaolin WANG Fan Key Laboratory of Ocean Circulation and Waves Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China Graduate School of Chinese Academy of Sciences Beijing 100049 China

On the basis of Argo data and historic temperature/salinity data from the World Ocean Database 2001 （ WOD01 ）, origins and spreading pathways of the subsurface and intermediate water masses in the Indonesian Throughflow （ITF） region were discussed by analyzing distributions of salinity on representative isopyenal layers. Results were shown that, subsurface water mostly comes from the North Pacific Ocean while the intermediate water originates from both the North and South Pacific Ocean, even possibly from the Indian Ocean. Spreading through the Sulawesi Sea, the Makassar Strait, and file Flores Sea, the North Pacific subsurface water and the North Pacific Intermediate water dominate the western part of the Indonesian Archipelago. Furthermore as the depth increases, the features of the North Pacific sourced water masses become more obvious. In the eastern part of the waters, high sa- linity South Pacific subsurface water is blocked by a strong salinity front between Halmahera and New Guinea. Intermediate water in the eastern interior region owns salinity higher than the North Pacific intermediate water and the antarctic intermediate water （ AAIW）, possibly coming from the vertical mixing between subsurface water and the AAIW from the Pacific Ocean, and possibly coming from the northward extending of the AAIW from the Indian Ocean as well.

关键词： Indonesian Throughflow subsurface water intermediate water origin pathway

Index of Kuroshio penetrating the Luzon Strait and its preliminary application

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Acta Oceanologica Sinica 2013年第1期32卷 1-11页

作者： yu xiaolin WANG Fan WAN Xiuquan Key Laboratory of Ocean Circulation and Waves Institute of Oceanology Chinese Academy of Sciences Graduate University of Chinese Academy of Sciences Ocean University of China

A method of quantifying the penetration of the Kuroshio into the Luzon Strait is improved with simulat- ed salinity. The new method is applied in an area bounded by 0.6 correlation coefficient contour to the point of 20°N, 118°E which is determined by EOF analysis. The results suggest that the method is suitable for indicating Kuroshio＇s intrusion into the South China Sea quantitatively. As an indicator, the Kuroshio penetrating the Luzon index （KLI） reveals obvious annual cycle and weak bi-modality. For annual period- s, indexes on the surface and subsurface which point the same events have totally opposite signs due to the winter burst of surface westward current. On long-term period, the surface and subsurface indexes have consistent signs. A subsurface index on 150 m avoiding high frequency signals from the surface can be used for indicating long-term Kuroshio intrusion variation. An anti-phase pattern in wavelet coherence map between KLI and Japan large meander index shows that the Luzon Strait is a ＂smoother＂ reducing the variability of the Kuroshio transport changes on long-term periods.

关键词： Kuroshio Luzon Strait penetration Index

Evaluation of mental fatigue based on multipsychophysiological parameters and kernel learning algorithms

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Chinese Science Bulletin 2008年第12期53卷 1835-1847页

作者： ZHANG Chong ZHENG ChongXun yu xiaolin Key Laboratory of Biomedical Information Engineering of Education Ministry Xi'an Jiaotong University Xi'an 710049 China

Mental fatigue is an extremely sophisticated phenomenon, which is influenced by the environment, the state of health, vitality and the capability of recovery. A single parameter cannot fully describe it. In this paper, the effects of long time sustained low-workload visual display terminal (VDT) task on psychology are investigated by subjective self-reporting measures. Then power spectral indices of HRV, the P300 components based on visual oddball and wavelet packet parameters of EEG are combined to analyze the impacts of prolonged visual display terminal (VDT) activity on autonomic nervous system and cen-tral nervous system. Finally, wavelet packet parameters of EEG are extracted as the features of brain activity in different mental fatigue states. Kernel principal component analysis (KPCA) and support vector machine (SVM) are jointly applied to differentiate two states. The statistic results show that the level of both subjective sleepiness and fatigue increase significantly from pre-task to post-task, which indicate that the long time VDT task induces the mental fatigue to the subjects. The predominant activ-ity of autonomic nervous system of subjects turns to the sympathetic activity from parasympathetic activity after the task. The P300 components and wavelet packet parameters of EEG are strongly related with mental fatigue. Moreover, the joint KPCA-SVM method is able to effectively reduce the dimension-ality of the feature vectors, speed up the convergence in the training of SVM and achieve a high rec-ognition accuracy (87%) of mental fatigue state. Multipsychophysiological measures and KPCA-SVM method could be a promising tool for the evaluation of mental fatigue.

关键词：心理疲劳脑电图心率诊断方法

Causal interactions between the cerebral cortex and the autonomic nervous system

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Science China(Life Sciences) 2014年第5期57卷 532-538页

作者： yu xiaolin ZHANG Chong ZHANG JianBao Department of Information Engineering Officers College of Chinese People's Armed Police Force Key Laboratory of Biomedical Information Engineering of Ministry of Education Xi'an Jiaotong University

Mental states such as stress and anxiety can cause heart *** the other hand,meditation can improve cardiac *** this study,the heart rate variability,directed transfer function and corrected conditional entropy were used to investigate the effects of mental tasks on cardiac performance,and the functional coupling between the cerebral cortex and the *** subjects tried to decrease their heart rate by volition,the sympathetic nervous system was inhibited and the heart rate *** subjects tried to increase their heart rate by volition,the parasympathetic nervous system was inhibited and the sympathetic nervous system was stimulated,and the heart rate *** autonomic nervous system activity was regulated by mental tasks,the information flow from the post-central areas to the pre-central areas of the cerebral cortex increased,and there was greater coupling between the brain and the *** of directed transfer function and corrected conditional entropy techniques enabled analysis of electroencephalographic recordings,and of the information flow causing functional coupling between the brain and the heart.

关键词： mental task autonomic nervous system cerebral cortex heart rate variability information flow

Stability Reliability of the Lateral Vibration of Footbridges Based on the IEVIE-SA Method

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Computer Modeling in Engineering & Sciences 2021年第8期128卷 565-582页

作者： Buyu Jia Siyi Mao Quansheng Yan xiaolin yu School of Civil Engineering and Transportation South China University of TechnologyGuangzhou510640China

Research on the lateral vibrational stability of footbridges has attracted increasing attention in recent years. However, this stability contains a series of complex mechanisms, such as nonlinear vibration, random excitation, andrandom stability. The Lyapunov method is regarded as an effective tool for analyzing random vibrational stability;however, it is a qualitative method and can only provide a binary judgment for stability. This study proposes anew method, IEVIE–SA, which combines the energy method based on the comparison between the input energyand the variation of intrinsic energy (IEVIE) and the stochastic averaging (SA) method. The improved Nakamuramodel was used to describe the lateral nonlinear stochastic vibration of a footbridge, whereby the IEVIE methodwas used to establish the criteria for judging the lateral vibrational stability. Additionally, the SA method was usedto deduce the corresponding backward Kolmogorov equation. Subsequently, the backward Kolmogorov equationwas combined with the stability criterion established by the IEVIE method to analyze the first passage stability. Theproposed method is a semi-analytical, quantitative method that only requires a small calculation. By applying theproposed method to the Millennium Bridge, method effectiveness was verified by comparing it with the MonteCarlo and traditional Lyapunov methods.

关键词： Footbridge vibration stability energy stochastic reliability

Novel Al-doped carbon nanotubes with adsorption and coagulation promotion for organic pollutant removal

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Journal of Environmental Sciences 2017年第4期29卷 1-12页

作者： Dongjuan Kang xiaolin yu Maofa Ge Feng Xiao Hui Xu State Key Laboratory for Structural Chemistry of Unstable and Stable Species Beijing National Laboratory for Molecular Sciences(BNLMS)Institute of ChemistryChinese Academy of Sciences State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of Sciences

Al-doped carbon nanotubes（Al-doped CNTs） were prepared as a multifunctional integrated material of adsorbent and coagulant aid for organic pollutant removal from aqueous solution. It was observed that aluminum species were dispersed homogeneously on the surface of CNTs, and mainly anchored onto defect structures of the CNTs. The introduction of aluminium efficiently improved adsorption ability for methyl orange（MO） onto the CNTs,and maximum adsorption capacity calculated from the Langmuir isotherm model can reach 69.7 mg/g. The MO adsorption kinetics can be better described by the pseudo-second-order and pore diffusion kinetic models, and the diffusion of MO anions into pores of the Al-doped CNT adsorbent should be the rate-determining *** analyses indicated that the adsorption of MO onto Al-CNTs-2.0 was endothermic and spontaneous. Moreover, adsorption capacity for MO on the Al-doped CNTs was evidently dependent on the CNT dose, solution p H and adsorbent dose. From the perspective of low-cost and multifunctional, suspension obtained during the Al-doped CNT adsorbent preparation, was tested as coagulant to remove humic acid（HA）. A significant observation is that the suspension exhibited an excellent coagulation performance for HA,because abundant aluminous polymer and Al-doped CNTs existed in the suspension.

关键词： Al-doped carbon nanotubes Adsorption Organic pollutants Methyl orange Aqueous solution

Neuronal conversion from glia to replenish the lost neurons

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Neural Regeneration Research 2024年第7期19卷 1446-1453页

作者： Shiyu Liang Jing Zhou xiaolin yu Shuai Lu Ruitian Liu National Key Laboratory of Biochemical Engineering Institute of Process EngineeringChinese Academy of SciencesBeijingChina School of Chemical Engineering University of Chinese Academy of SciencesBeijingChina Department of Geriatric Rehabilitation Beijing Rehabilitation HospitalCapital Medical UniversityBeijingChina

Neuronal injury,aging,and cerebrovascular and neurodegenerative diseases such as cerebral infarction,Alzheimer’s disease,Parkinson’s disease,frontotemporal dementia,amyotrophic lateral sclerosis,and Huntington’s disease are characte rized by significant neuronal *** rtunately,the neurons of most mammals including humans do not possess the ability to *** of lost neurons becomes an appealing therapeutic strategy to reve rse the disease *** of pluripotent neural stem cells can supplement the missing neurons in the brain,but it carries the risk of causing gene mutation,tumorigenesis,severe inflammation,and obstructive hydrocephalus induced by brain *** of neural or non-neural lineage cells into functional neurons is a promising strategy for the diseases involving neuron loss,which may overcome the above-mentioned disadvantages of neural stem cell *** far,many strategies to transfo rm astrocytes,fibroblasts,microglia,Muller glia,NG2 cells,and other glial cells to mature and functional neurons,or for the conversion between neuronal subtypes have been developed thro ugh the regulation of transcription factors,polypyrimidine tra ct binding protein 1(PTBP1),and small chemical molecules or are based on a combination of several factors and the location in the central nervous ***,some recent papers did not obtain expected results,and discrepancies ***,in this review,we discuss the history of neuronal transdifferentiation,summarize the strategies for neuronal replenishment and conversion from glia,especially astrocytes,and point out that biosafety,new strategies,and the accurate origin of the truly co nverted neurons in vivo should be focused upon in future *** also arises the attention of replenishing the lost neurons from glia by gene therapies such as up-regulation of some transc ription factors or downregulation of PTBP1 or drug interfe rence therapies.

关键词： astrocytes neural stem cells neurodegenerative diseases neuron polypyrimidine tract binding protein 1 repair reprogramming small molecule transcription factor transdifferentiation

Confining shell-sandwiched Ag clusters in MnO_(2)-CeO_(2)hollow spheres to boost activity and stability of toluene combustion

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Nano Research 2022年第8期15卷 7042-7051页

作者： Menglan Xiao Xueqin Yang yue Peng yucong Guo yuechang Wei Maofa Ge xiaolin yu State Key Laboratory for Structural Chemistry of Unstable and Stable Species Beijing National Laboratory for Molecular Sciences(BNLMS)CAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China College of Forestry Henan Agricultural UniversityZhengzhou 450002China Center for Excellence in Regional Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China School of Environment Tsinghua UniversityBeijing 100084China State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China University of Chinese Academy of Sciences Beijing 100049China

Supported noble metal catalysts have the promising application in volatile organic compounds(VOCs)catalytic combustion but suffer from the deactivation due to noble metal sintering at high ***,we report the construction of shellsandwiched MnO_(2)-Ag-CeO_(2)hollow spheres with remarkable sintering resistance and high activity in toluene *** clusters were sandwiched between outer MnO_(2)and inner CeO_(2)shell to enlarge and stabilize metal–support active *** unique hollow structure could alter the electronic states of catalysts sites and increase the adsorbed site of reactant ***,Mn–Ag–Ce multi-interfaces in MnO_(2)-Ag-CeO_(2)could facilitate the sustainable activation and the stable release of oxygen species via a tandem *** oxygen species at Ag–Mn interface perimeter were instantly replenished by Ag–Ce interface to accelerate a deep oxidation of intermediates,guaranteeing the opening of benzene ring to generate maleic *** investigation provides a promising method for constructing efficient and sintering-resistant cluster catalysts for VOCs oxidation.

关键词： hollow spheres multi-interfaces toluene combustion active lattice oxygen