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Rolling Element Bearing Diagnostics by Combination of Envelope Analysis and Wavelet Transform

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Journal of university of science and Technology beijing 2001年第1期8卷 69-74页

作者： Ying Tang, Qiao Sun Mechanical engineering School, university of science and Technology {3., {3. 100083. China Department of Mechanical engineering, university of Calgary Calgary Alberta T2N 1N4. Canada Univ Sci & Technol beijing Sch Mech Engn Beijing 100083 Peoples R China Univ Calgary Dept Mech Engn Calgary AB T2N 1N4 Canada

Rolling element-bearing diagnostics has been studied over the last thirty years, and envelope analysis is widely recognized as being the best approach for detection and diagnosis of rolling element bearing incipient failure. But one of the on-going difficulties with envelope technique is to determine the best frequency band to envelop. Here, wavelet transform technique is introduced into envelope analysis to solve the problem by capturing bearing defects-sensory scales (i.e. frequency bands). A modulated Gaussian function is chosen to be the analytical wavelet because it coincides well with bearing defect-induced vibration signal patterns. Vibration signals measured from railway bearing tests were studied by the proposed method. Cases of bearings with single and multiple defects on inner and outer race under different testing conditions are presented. Experimental results showed that the proposed method allowed a more accurate local description and separation of transient signal part, which were caused by impacts between defects and the mating surfaces in the bearing. The combination method provides an effective signal detection technique for rolling element-bearing diagnostics.

关键词： continuous wavelet transform envelope analysis rolling element bearing diagnostics

Preparation and characterization of nano-crystalline diamond films on glass substrate

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Journal of university of science and Technology beijing 2004年第3期11卷 216-220页

作者： Fanxiu Lu Wubao Yang Zhilin Liu Weizhong Tang Yumei Tong Materials science and engineering School, university of science and Technology {4., {4. 100083. China Materials science and engineering School University of Science and Technology Beijing Beijing 100083 China

Adherent nano diamond films were successfully deposited on glass substrate bymicrowave plasma assisted CVD method in H_2-CH_4.and Ar-CH_4.environment. Raman, AFM (Atomic ForceMicroscope), TEM (Transmission Electron Microscope), FTIR, and Nano Indentation techniques were usedfor characterization of the obtained nano diamond films. It was found that the average grain sizewas less than 100 nm with a surface roughness value as low as 2 nm. The nano diamond films werefound to have excellent transparency in visible and IR spectrum range, and were as hard as naturaldiamond. Experimental results were presented. Mechanisms for nano diamond film deposition werediscussed.

关键词： nano diamond films microwave plasma assisted CVD characterization glasssubstrate

Thermodynamic Properties of Mn-P and Fe-Mn-P Melts

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International Journal of Minerals,Metallurgy and Materials 2000年第1期14卷 10-13页

作者： Jian Zhang Rong Zhu Metallurgy School, university of science and Technology beijing, beijing {4. China Univ Sci & Technol beijing Met Sch Beijing 100083 Peoples R China

Based on the phase diagrams and the coexistence theory of metallic melts structure involving compound formation, the cal- culating models of mass action concentrations for Mn-P and Fe-Mn-P melts have been formulated. The calculated mass action concen- trations agree well with the corresponding measured activities, this in turn shows that the deduced models can reflect the structural char- acteristics of the melts concerned and there isn't any saturation of phosphorus in both melts.

关键词： activity dephosphorization the coexistence theory mass action concentration

Role of inositol 1,4.5-trisphosphate receptors in α1-adrenergic receptorinduced cardiomyocyte hypertrophy

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Acta Pharmacologica Sinica 2006年第7期27卷 895-900页

作者： Da-li LUO~(2,3.5) Jian GAO~2 Xiao-mei LAN~3.Gang WANG~4.Sheng WEI~4.Rui-ping XIAO~4.Qi-de HAN~3. Department of Pharmacology,School of Chemical Biology & Pharmaceutical {3.s,Capital university of Medical {3.s,beijing 100069,China 3.Institute of Cardiovascular {3. at Health {3. Center,Peking university beijing 100083.China 4.Institute of Molecular Medicine and College of Life {3.,Peking university,beijing 100871,China Department of Pharmacology School of Chemical Biology & Pharmaceutical Sciences Capital University of Medical Sciences Beijing 100069 China Institute of Cardiovascular science at Health science Center Peking University Beijing 100083 China Institute of Molecular Medicine and College of Life science Peking University Beijing 100871 China

Aim:Intracellular Ca2+plays pivotal roles in diverse cellular functions,includinggene transcription that underlies cardiac remodeling during stress ***,the role of inositol 1,4.5-trisphosphate receptors（IP3.s）in the media-tion of cardiac intracellular Ca2+and hypertrophic growth remains *** with neonatal rat ventricular myocytes suggests that activation of IP3.smay be linked to α1adrenergic receptor（α1AR）increased stereotyped Ca2+sparkoccurrence and global Ca2+***,we hypothesized that Ca2+releasethrough IP3.s was necessary for α1AR-stimulated cardiac ***:We used myoinositol 1,4.5-trisphosphate hexakis（butyryloxymethyl）ester（IP3.M）,a membrane-permeant ester of IP3.to activate IP3.s directly,and Fluo 4.AM tomeasure intracellular Ca2+***:IP3.M(10μmol·L-1)mimicked theeffects of phenylephrine,a selective agonist of α1AR,in increments in local Ca2+spark release（especially in the perinuclear area）and global Ca2+*** importantly,IP3. inhibitors,2-aminoethoxydiphenyl borateand Xestospongin C,abolished the IP3.M-induced Ca2+responses,and signifi-cantly suppressed α1AR-induced cardiomyocyte hypertrophy assayed by cellsize,[3.]leucine incorporation and atrial natriuretic factor gene expression,dur-ing sustained（4. h）phenylephrine ***:These results,therefore,provide cellular mechanisms that link IP3. signaling to α1AR-stimulatedgene expression and cardiomyocyte hypertrophy.

关键词： inositol 1,4.5-trisphosphate receptors Ca2+sparks α1 adrenergic stimulation cardiac hypertrophy

Numerical simulation of strain localization and damage evolution in large plastic deformation using mixed finite element method

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Journal of university of science and Technology beijing 2004年第3期11卷 273-277页

作者： Zhanghua Chen Jiajian Jin Jiumei Xiao Applied science School, university of science and Technology {3., {3. 100083. China Applied science School University of Science and Technology Beijing Beijing 100083 China

An investigation of computer simulation is presented to analyze the effectsof strain localization and damage evolution in large plastic deformation. The simulation is carriedout by using an elastic-plastic-damage coupling finite element program that is developed based onthe concept of mixed interpolation of displacement/pressure. This program has been incorporated intoa damage mechanics model as well as the corresponding damage criterion. To illustrate theperformance of the proposed approach, a typical strain localization problem has been simulated. Theresults show that the proposed approach is of good capability to capture strain localization andpredict the damage evolution.

关键词： strain localization mixed element truesdell stress rate material damage

Improved Algebraic Model for Serial Production Lines with Limited Buffer Sizes

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International Journal of Minerals,Metallurgy and Materials 1999年第2期13卷 139-143页

作者： Ke Liu Zhichun Mu Datai Yu Dal Koshal David Pearce(Information engineering School,university, of science and Technology {3., {3. 100083. China) (School of engineering, university of Brighton, Brighton Brighton BN2 4.J UK Univ of science and Technology Beijing Beijing China

The ordered event model is improved to describe serial production lines with limited buffer sizes. The improved model hasthe same computational burden as the original one and can be constrUcted directly according to given principles. Several simulationexamples are cited to verify this improved model. Extensions and open problems are also indicated. By means of this new model, serialProduotion lines with limitations of resources can be stUdied analytically.

关键词： ordered event model serial production line buffer size period

High Temperature Ductility Loss of 16MnCr5 Pinion Steels

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International Journal of Minerals,Metallurgy and Materials 1998年第3期12卷 123-128页

作者： Haiwen Luo Pei Zhao Zijiu Dang(Metallurgy School, university of science and Technology beijing, beijing {4. China) Metallurgy School University of Science and Technology Beijing Beijing 100083 China

A wide ductility trough covering from 700 to 1100 is observed in the curve of Reduction of Area (RA) *** for 16MnCr5 pinion steel. At 750℃, corresponding to the minimum of RA, it is grain boundary slidingthat controls its hot ductility rather than usual Deforming Induced Ferrite (DIF), which can only appear just below750℃ and slightly improve hot ductility. The volume fraction of ferrite is dependent on the strain and strain *** a critical strain must be necessary for formation of DIF then with strain rate increasing, the volume fractionof DIF decreases but RA is elevated. In the γ phase region, hot ductility is seriously deteriorated because of grainboundary sliding promoted by oxidcs and sulfides at the grain boundary and recovered because of dynamic recrystal-lization at higher temperature; when strain rate increases, ductility is improved as there is insufficient time for cracksto propagate along the γ grain boundary as well as dynamically precipitating, and ductility trough becomes narrowerbecause the temperature for onset of dynamic recrystallization decreases. In addition, γ→α phase transformationintroduced by temperature drop before the tensile test encourages precipitation of AlN and impairs ductility.

关键词： hot ductility deforming induced ferrite grain boundary sliding precipitates

Response synchronization: New progress in brain-visual information processing

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Chinese science Bulletin 1999年第16期44卷 1447-1458页

作者： ZHAO Songnian, XIONG Xiaoyun, YAO Guozheng and GUO Aike1. State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry , Institute of Atmospheric Physics , Chinese Academy of sciences , beijing 100029, China 2. Commission of the National Natural science Foundation of China , beijing {4. China 3. The Center of Information science , Peking university, beijing 100871, China 4. Open Laboratory of Visual Information Processing , Institute of Biophysics , Chinese Academy of sciences , beijing 100101, China State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China Commission of the National Natural science Foundation of China Beijing China The Center of Information science Peking University Beijing China Open Laboratory of Visual Information Processing Institute of Biophysics Chinese Academy of Sciences Beijing China

Studies on brain-vision have entered a new stage, after the stimulus-induced y synchronized oscillation of neuron group activities have been discovered in cat primary visual cortex. Naturally, how to understand the visual system became a very important methodological problem. From aspects such as information processing, nonlinear dynamics and neuronal network, some primary problems in vision studies have been deeply discussed, which are

关键词： neuron group (neural population) synchro-oscillation computational theory of vision response synchroniza-tion.

Exotic structure of the third excited state in^(21)Na

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Chinese science Bulletin 2005年第23期50卷 2677-2680页

作者： LI Xihan1,2,3. LIANG Yujie1,2,3. DENG Fuguo1,2,3. LIU Zuhua1,4.& ZHOU Hongyu1,2,3.1. Key Laboratory of Beam Technology and Material Modification of Minister of Education, beijing Normal university, beijing 100875, China 2. Institute of Low Energy Nuclear Physics, and Department of Material science and {4., beijing Normal university, beijing 100875, China 3. beijing Radiation Center, beijing 100875, China 4. China Institute of Atomic Energy, beijing 1024.3. China Key Laboratory of Beam Technology and Material Modification of Minister of Education Beijing Normal University Beijing 100875 China Institute of Low Energy Nuclear Physics and Department of Material Science and Engineering Beijing Normal University Beijing 100875 China beijing Radiation Center Beijing 100875 China China Institute of Atomic Energy Beijing 102413 China

The probability of the last proton being out of the binding potential, P and the root-mean-square (rms) ra- dius (1/2= of the third excited state in 21Na are calcu- lated by means of asymptotic normalization coefficient (ANC) method with the experimental date existing. The results are P=54.73. and 1/2=5.28 fm respectively. The P value and the contribution of the asymptotic part to the 1/2 are compared with those of several other low energy states in 21Na. It is found that the valence particle in the third excited state has an obvious larger P than those of other states. The density distribution of the valence proton in this state is also compared with the nucleons in the nuclear core 20Ne, and a far extended tail can be seen clearly. These results show that the third ex- cited state in 21Na is a proton halo state.

关键词：钠第三激发态外部结构有效半径密度分布渐近标准化系数