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Modeling of growth stress gradient effect on the oxidation rate at high temperature

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第10期11卷 789-793页

作者： Fan YANG Bin LIU Dai-ning fang Applied Mechanics Laboratory Department of Engineering Mechanics Tsinghua University Beijing 100084 China State Key Laboratory for Turbulence and Complex Systems College of Engineering Peking University Beijing 100871 China

A new oxidation kinetics model is established for high-temperature oxidation. We assume that the interface reaction is fast enough and the oxidation rate is controlled by diffusion process at high temperature. By introducing the growth stress gradient we modify the classical oxidation parabolic law. The modified factor of the oxidation rate constant is a function of growth strain, environment oxygen concentration, and temperature. The modeling results show that the stress gradient effect on the oxidation rate cannot be ignored. Growth strain will dominate whether the stress gradient effect promotes or slows down the oxidation process. The stress gradient effect becomes weaker at higher temperature. This effect is amplified at higher concentrations of environmental oxygen. Applied mechanical loads do not affect the oxidation rate. This model is available for high temperature oxidation of metals and alloys.

关键词： High temperature Modeling Growth stress gradient Oxidation rate

On the behaviour characterization of metallic cellular materials under impact loading

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Acta Mechanica Sinica 2010年第6期26卷 837-846页

作者： Dai-ning fang Yu-Long Li Han Zhao College of Engineering Peking University 100871 BeijingChina School of Aeronautics Northwestern Polytechnical University 710072 Xi'anChina Laboratoire de Mecanique et Technologie ENS-Cachan/CNRS-UMR8535/Universite Pierre and Marie Curie61avenue du president Wilson 94235 Cachan CedexFrance

This paper reviews the common mechanical features of the metallic cellular material under impact loading as well as the characterization methods of such behaviours. The main focus is on the innovations of various testing methods at impact loading *** aspects were discussed in details.（1） The use of soft nylon Hopkinson/Kolsky bar for an enhanced measuring accuracy in order to assess if there is a strength enhancement or not for this class of cellular materials under moderate impact loading;（2） The use of digital image correlations to determine the strain fields during the tests to confirm the existence of a pseudo-shock wave propagation inside the cellular material under high speed impact：（3） The use of new combined shear compression device to determine the loading envelop of cellular materials under impact multiaxial loadings.

关键词： Foam Honeycomb Lattice Hopkinson bar Rate sensitivity

Wind Generator Tower Vibration Fault Diagnosis and Monitoring Based on PCA

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Wind Generator Tower Vibration Fault Diagnosis and Monitorin...

Identification of seven long noncoding RNAs signature for prediction of biochemical recurrence in prostate cancer

第25届中国控制与决策会议

作者： ning fang Peng Guo School Of Control and Computer Engineering North China Electric Power University

ISBN: (纸本)9781467355322

Vibration signal is one kind of important variables for wind turbine in Supervisory Control and Data Acquisition （SCADA） System. With modeling and analysis of vibration signals, incipient failure of key components such as tower, drive train and rotor could be detected. In this paper, Principal Component Analysis （PCA） was applied to model the tower vibration providing a good understanding of the tower vibration dynamic characteristics and the main factors influencing these. The merits and physical interpretation of PCA are also discussed and analyzed. With SCADA of one wind turbine during April to June in 2006, PCA model for tower vibration in normal working condition was established and validated. This method monitoring the operation of the wind generator by calculating the monitoring statistic Hotelling T2 （T2 for short） and SPE. If T2 and SPE statistics over confidence limit, the decision system is abnormal. We can calculate contribution rate of each variable on the main component then get the cause of the fault . Wind generator fault data set simulation verify the effectiveness of the proposed method.

关键词： Condition monitoring Tower vibration Principal Component Analysis Modeling

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Asian Journal of Andrology 2019年第6期21卷 618-622页

作者： ning Shao Wo Zhu fang-ning Wan Ding-Wei Ye Department of Urology Fudan University Shanghai Cancer CenterShanghai 200032China Department of Oncology Shanghai Medical CollegeFudan UniversityShanghai 200032China.

Accumulating evidenee suggested that long noncoding RNAs(IncRNAs)possess a potential role in prostate cancer(PCa)diagnosis and *** biochemical recurrence(BCR)is considered as a sign for clinical recurrence metastasis and PCa-specific ***,the aim of the present study was to identify a IncRNA signature that can predict BCR of PCa *** analysis,Kaplan-Meier analyses,Cox regression analyses,and Gene Set Enrichment Analysis(GSEA)were performed in a publicly available database with 499 PCa tissues and 52 matched normal tissues.A signature was *** these IncRNAs were differentially expressed between tumor and normal tissues and differentially expressed between high Gleason score and low Gleason score ***,we developed a seven IncRNAs signature that can predict PCa *** classified into low-risk group showed better BCR survival significantly than the patients in the high-risk group(hazard ratio=0.32,95%Cl:0.20-0.52,concordance index=0.63).The area under the curve was 0.68 for *** signature also had good discrimination for BCR in men with Gleason 7 *** conclusion,our results suggest that the seven IncRNAs signature is a new biomarker of BCR and high risk in *** addition,the in dividual In cRNA warrants further study to un cover the associated mechanisms of PCa progression and the signature could be used to design direct clinical trials for adjuvant therapy.

关键词： biochemical recurrence biomarker high risk Iong noncoding RNA prostate cancer

Perturbation and Adiabatic Invariants of Mei Symmetry for Nonholonomic Mechanical Systems

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Communications in Theoretical Physics 2007年第4期47卷 594-596页

作者： DING ning fang Jian-Hui WANG Peng College of Physical Science and Technology China University of Petroleum Dongying 257061 China

Based on the concept of adiabatic invariant, the perturbation and adiabatic invariants of the Mei symmetry for nonholonomic mechanical systems are studied. The exact invariants of the Mei symmetry for the system without perturbation are given. The perturbation to the Mei symmetry is discussed and the adiabatic invariants of the Mei symmetry for the perturbed system are obtained.

关键词： Mei symmetry perturbation adiabatic invariant nonholonomic mechanical system

Mechanics of advanced fiber reinforced lattice composites

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Acta Mechanica Sinica 2010年第6期26卷 825-835页

作者： Hua-Lin Fan Tao Zeng Dai-ning fang Wei Yang College of Mechanics and Materials Hohai University Nanjing 210098China Key Laboratory for Advanced Building Materials of Sichuan Province Southwest University of Science and Technology Mianyang 621010China College of Civil Engineering and Architecture Harbin University of Science and TechnologyHarbin 150080China College of Engineering Peking University Beijing 100871China University Office Zhejiang University Hangzhou 310058China

Fiber reinforced lattice composites are lightweight attractive due to their high specific strength and specific *** the past 10 years,researchers developed three-dimensional（3D） lattice trusses and two-dimensional （2D） lattice grids by various methods including interlacing, weaving,interlocking,filament winding and molding hot- *** lattice composites have been applied in the fields of radar cross-section reduction,explosive absorption and heat-resistance. In this paper,topologies of the lattice composites, their manufacturing routes,as well as their mechanical and multifunctional applications,were surveyed.

关键词： Lattice composites Mechanical behaviors Fabrication Multifunction

Microstructural evolution and precipitation behavior of Al-7Si-3Cu alloy prepared under 5 GPa

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Journal of Materials Science & Technology 2023年第28期159卷 138-150页

作者： ning fang Chunming Zou Zunjie Wei Hongwei Wang Jiahan Chen Zongyue Jin Key Laboratory for Precision Hot Processing of Metals Harbin Institute of Technology150001 HarbinChina

This paper presents a systematic investigation of the microstructural evolution and mechanical proper-ties of Al-7Si-3Cu alloys prepared under high pressure of 5 *** is found that the dendritic structure disappears due to the enhanced stability of the growth interface under high ***,a con-siderable solute-induced modification effect is achieved in the eutectic ***,unconventional larger eutectic colonies and ultrafine nanocrystalline eutectics are observed within the intragranular ***-bined with detailed microstructural characterization,the crucial role of high pressure on the evolution of these isolated phases is *** study also explores the precipitation behavior and strengthening mechanisms of alloys prepared under direct aging and solution-aging *** the direct aging treatment,θ’phases,coarse Al 2 Cu particles,and Si particles form simultaneously in the matrix owing to the increased solid solubility of alloying elements,which results in the highest mechanical properties with a microhardness of 132.8 HV and compressive stress of 715 ***-aging treatment leads to the segregation of Si onθ’phases,which proved to be energetically favorable according to first-principles *** work provides new insights into the microstructural optimization of aluminum-silicon-based alloys through high-pressure manipulation and paves the way for further industrial applications.

关键词： Al-Si-Cu alloy High pressure Nanocrystalline eutectics Precipitates Mechanical properties

Stability analysis of the sliding process of the west slope in Buzhaoba Open-Pit Mine

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International Journal of Mining Science and Technology 2016年第5期26卷 869-875页

作者： ning fang Ji Changsheng Garmondyu E.Crusoe Jr. School of Art and Design School of Mines China University of Mining & Technology

To study the stability of the west slope in Buzhaoba Open-Pit Mine and determine the aging stability coefficient during slide mass development, the deformation band of the west slope and the slide mass structure of the 34,600 profile are obtained on the basis of hydrology, geology, and monitoring *** residual thrust method is utilized to calculate the stability coefficients, which are 1.225 and 1.00 under sound and transfixion conditions, respectively. According to the rock damage and fragmentation and the principle of mechanical parameter degradation, the mechanical models of the slide mass development of the hard and soft rock slopes are established. An integrated model for calculating the slope stability coefficient is built considering water, vibration, and other external factors that pertain to the structural plane damage mechanism and the generating mechanism of the sliding mass. The change curve of the stability coefficient in the slide mass development is obtained from the relevant analyses,and afterwards, the stability control measures are proposed. The analysis results indicate that in the cracking stage of the hard rock, the slope stability coefficient decreases linearly with the increase in the length Lbof the hard rock crack zone. The linear slope is positively correlated to rock cohesion c. In the transfixion stage of the soft rock, the decrease speed of the stability coefficient is positively correlated to the residual strength of the soft rock. When the slope is stable, the stability coefficient is in a quadratic-linear relationship with the decreased height Dh of the side slope and in a linear relationship with anchoring force P.

关键词： Open-pit mine Side slope Sliding process Aging stability Crack zone

A New Type of Conserved Quantity of Mei Symmetry for Lagrange Systems

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Communications in Theoretical Physics 2007年第5X期48卷 799-800页

作者： DING ning fang Jian-Hui WANG Peng ZHANG Xiao-Ni College of Physics Science and Technology China University of Petroleum Dongying 257061 China

A new type of conserved quantity, which is induced from the Mei symmetry of Lagrange systems, is studied. The conditions for that the new type of conserved quantity exists and the form of the new type of conserved quantity are obtained. An illustrated example is given. The Noether conserved quantity induced from the Mei symmetry of Lagrange systems is a special case of the new type of conserved quantity given in this paper.

关键词： Mei symmetry new type of conserved quantity Lagrange system