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Rubbing-Induced Vibration Response Analysis of Dual-Rotor-Casing System

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Transactions of Nanjing University of Aeronautics and Astronautics 2018年第1期35卷 101-108页

作者： Ma Xinxing Ma Hui zeng jin Piao Yuhua School of Mechanical Engineering and Automation Northeastern University State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong University

Considering gyroscopic effects caused by rotational speed,torsional vibration as well as coupling effects among inner rotor,out rotor and casing,a dynamic model of the dual-rotor-casing system is established using finite element(FE)*** comparing the natural characteristics obtained from MATLAB and ANSYS,the developed model is *** rubbing-induced vibration responses in dual-rotor-casing system are *** effects of rotational speed and speed ratio on rubbing vibration responses of the system are *** show that different combined frequency components will appear in the spectrum except two unbalanced excitation frequencies and their multiple frequency components,and these frequencies can be used as the dual-rotor aero-engine rubbing failure diagnosis frequencies when rubbing ***,the amplitude of torsional vibration is larger than that of lateral vibration under the same working condition,and speed ratio has a great impact on the periodicity of the system rubbing-induced motion *** amplitude of rubbing-induced responses under counter-rotation is less than that under co-rotation with the same parameters.

关键词： dual-rotor-casing system rubbing fault finite element method coupling dynamic

Coupled flapwise-chordwise-axial-torsional dynamic responses of rotating pre-twisted and inclined cantilever beams subject to the base excitation

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Applied Mathematics and Mechanics(English Edition) 2019年第8期40卷 1053-1082页

作者： jin zeng Hui MA Kun YU Zhitao XU Bangchun WEN School of Mechanical Engineering and Automation Northeastern University Shenyang 110819China Key Laboratory of Vibration and Control of Aero-Propulsion System Ministry of Education Northeastern UniversityShenyang 110819China

A rotating pre-twisted and inclined cantilever beam model (RPICBM) with the flapwise-chordwise-axial-torsional coupling is established with the Hamilton principle and the finite element (FE) method. The effectiveness of the model is verified via comparisons with the literatures and the FE models in ANSYS. The effects of the setting and pre-twisted angles on the dynamic responses of the RPICBM are analyzed. The results show that:(i) the increase in the setting or pre-twisted angle results in the increases in the first-order flapwise and torsional frequencies while the decrease in the first-order chordwise frequency under rotating conditions;(ii) a positive/negative setting angle leads to a positive/negative constant component, while a positive/negative pre-twisted angle leads to a negative/positive constant component;(iii) when the rotation speed is non-zero, the pre-twisted angle or non-zero setting angle will result in the coupled flapwise-chordwiseaxial- torsional vibration of the RPICBM under axial base excitation.

关键词： modal characteristic vibration response flapwise-chordwise-axial-torsional base excitation rotating Timoshenko beam

Lower Cretaceous turbidites in the Shiquanhe–Namco Ophiolite Mélange Zone, Asa area, Tibet: Constraints on the evolution of the Meso-Tethys Ocean

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Geoscience Frontiers 2021年第4期12卷 1-20页

作者： Xiao-Wen zeng Ming Wang Cai Li Hang Li Xian-jin zeng Di Shen College of Earth Sciences Jilin UniversityChangchun 130062China Key Laboratory of Mineral Resources Evaluation in Northeast Asia Ministry of Natural Resources of ChinaChangchun 130062China

Turbidites fromthe Shiquanhe–Namco OphioliteMélange Zone(SNMZ)record critical information about the tectonic affinity of the SNMZand the evolutionary history of theMeso-Tethys Ocean in *** paper reports sedimentologic,sandstone petrographic,zircon U-Pb geochronologic,and clastic rocks geochemical data of newly identified turbidites(Asa Formation)in the Asa Ophiolite Mé*** youngest ages of detrital zircon from the turbiditic sandstone samples,together with~115 Ma U-Pb concordant age from the tuff intercalation within the Asa Formation indicate an Early Cretaceous *** sandstone mineral modal composition data show that the main component is quartz grains and the minor components are sedimentary and volcanic fragments,suggesting that the turbidites were mainly derived froma recycled orogen provenancewith a minor addition of volcanic arc *** detrital U-Pb zircon ages of turbiditic sandstones yield main age populations of 170–120 Ma,300–220 Ma,600–500 Ma,1000–700 Ma,1900–1500 Ma,and~2500 Ma,similar to the ages of the Qiangtang Terrane(age peak of 600–500 Ma,1000–900 Ma,~1850 Ma and~2500 Ma)and the accretionary complex in the Bangong–Nujiang Ophiolite Zone(BNMZ)rather than the age of the Central Lhasa Terrane(age peak of~300 Ma,~550 Ma and~1150 Ma).The mineral modal compositions,detrital U-Pb zircon ages,and geochemical data of clastic rocks suggest that the Asa Formation is composed of sediments primarily recycled from the Jurassic accretionary complex within the BNMZ with the secondary addition of intermediate-felsic island arc materials from the South Qiangtang *** on our new results and previous studies,we infer that the SNMZ represents a part of the Meso-Tethys Suture Zone,rather than a southward tectonic klippe of the BNMZ or an isolated ophiolitic mélange zone within the Lhasa *** Meso-Tethys Suture Zone records the continuous evolutionary history of the northward subduction,accretion,arc-Lhasa collision,and Lhasa-Qiangta

关键词： Tibet Shiquanhe–Namco Ophiolite Mélange Zone Early Cretaceous Sedimentary provenance Tectonic Affinity Meso-Tethys Ocean

Improved Z^(1/3) Law of Nuclear Charge Radius

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Communications in Theoretical Physics 2009年第1期51卷 123-125页

作者： LEI Yi-An ZHANG Zhen-Hua zeng jin-Yan School of Physics Peking University Beijing 100871 China

An improved Z^1/3 law of nuclear charge radius is presented. The comparison between the calculated and experimental nuclear charge radii now available shows that this new formula is better than the other conventional ... 详细信息

关键词： nuclear charge radius improved Z^1/3 law isospin dependence

Investigation on dynamic characteristics of a rod fastening rotor-bearing coupling system with fixed-point rubbing

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Applied Mathematics and Mechanics(English Edition) 2022年第7期43卷 1063-1080页

作者： Yang YANG HJOUYANG jin zeng Hui MA Yiren YANG Dengqing CAO School of Mechanics and Engineering Southwest Jiaotong UniversityChengdu 610031China Centre for Engineering Dynamics School of EngineeringUniversity of LiverpoolLiverpool L693GHU.K. School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819China School of Astronautics Harbin Institute of TechnologyHarbin 150001China

The aim of this paper is to gain insight into the nonlinear vibration feature of a dynamic model of a gas ***,a rod fastening rotor-bearing coupling model with fixed-point rubbing is proposed,where the fractal theory and the finite element method are *** contact analysis,a novel contact force model is introduced in this ***,the Coulomb model is adopted to expound the friction ***,the governing equations of motion of the rotor system are numerically solved,and the nonlinear dynamic characteristics are analyzed in terms of the bifurcation diagram,Poincarémap,and time ***,the potential effects provided by contact degree of joint interface,distribution position,and amount of contact layer are discussed in ***,the contrast analysis between the integral rotor and the rod fastening rotor is conducted under the condition of fixed-point rubbing.

关键词： rod fastening rotor joint interface fixed-point rubbing nonlinear dynamic characteristic

Microscopic Mechanism of the Odd-Even Difference in Moments of Inertia of Superdeformed Bands

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Chinese Physics Letters 2000年第12期17卷 871-873页

作者： LIU Shu-Xin YU Lei zeng jin-Yan Department of Physics Peking UniversityBeijing 100871

The large odd-even difference in moments of inertia between the SD bands l95Tl(l,2)and l96Pb(l)is investigated by the particle-number conserving method,in which the blocking effect on pairing is taken into account ***ωvariation of J(2)for the three SD bands are reproduced quite well and the underlying microscopic mechanism is demonstrated *** show that the blocking of the proton[642]5/2 intruder orbital and the excitation of[651]1/2 intruder orbital play crucial roles for the odd-even difference in J(2)’s.

关键词： bands orbital excitation

Comparison of heavy metal accumulation by a bloom-forming cyanobacterium,Microcystis aeruginosa

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Chinese Science Bulletin 2012年第28期57卷 3790-3797页

作者： zeng jin ZHAO DaYong JI YongBan WU QingLong State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing 210008China State Key Laboratory of Hydrology-Water Resources and Hydraulie Engineering College of Hydrology and Water Resources Hohai UniversityNanjing 210098China

Microcystis aeruginosa is the dominant species during cyanobacterial blooms in freshwater *** the present study,we compared the bioaccumulation characteristics of cadmium(Cd) and zinc(Zn) in Microcystis *** short-term uptake tests,a rapid sorption of Cd and Zn occurred in the first few minutes,with a subsequent slower internalization *** obvious difference was observed between Zn and Cd in terms of their short-term uptake *** efflux experiments,elimination of Zn from the cells was faster than that of *** the 72-h exposure tests,the intracellular Cd concentrations increased with exposure time whereas the intracellular Zn concentrations always reached a *** cellular Cd showed greater variation than the cellular Zn at various free Cd 2+ or Zn 2+ *** differences in Cd and Zn accumulation and elimination indicated that Microcystis cells had a higher bioaccumulation capacity for Cd than for *** field studies,the bioconcentration factor(BCF) of Cd in lake-harvested Microcystis was more than 10 times higher than those of other *** results of the present study strongly suggested that the bloom-forming Microcystis may affect the Cd transportation and biogeochemical cycling in eutrophic freshwater ecosystems.

关键词：铜绿微囊藻重金属积累蓝藻水华镉(Cd) 生物地球化学循环吸收动力学生物富集淡水生态系统

Blade-Loss-Caused Rubbing Dynamic Characteristics of Rotor-Bladed Disk-Casing System

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Transactions of Nanjing University of Aeronautics and Astronautics 2018年第1期35卷 116-125页

作者： zeng jin Ma Hui Ma Xinxing Wu Zhiyuan Qin Zhaoye School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819P.R.China State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240P.R.China Shanghai Institute of Space Power-Sources Shanghai 200245P.R.China Department of Mechanical Engineering Tsinghua UniversityBeijing 100084P.R.China

Considering the elastic supports,the finite element model of rotor-bladed disk-casing system is established using commercial software ANSYS/*** that broken blade is released from the disk,the complicate rubbing responses of unbalanced rotor-bladed disk-casing system are studied under different operational *** addition,influences of both plastic deformation of blade and casing failure are *** results show that there exist some multiple even fractional frequencies in the transient and steady vibration responses of unbalanced ***,one nodal diameter vibration of bladed disk coupling with the lateral vibration of the shaft as well as the first order bending vibration of blade can be excited under low operational speed,while the first order bending vibration of blade coupling with the lateral vibration of disk-shaft is easily excited under high operational *** rubbing process,three distinct contact states can be observed:broken blade-casing contact,broken blade-blade component-casing contact and broken blade-casing contact/blade component-casing contact/blade *** is worth noting that the third contact state is related to the operational *** the increase of operational speed,self-contact in the blade may occur.

关键词： rotor-bladed disk-casing system blade loss rubbing casing failure elastic supports

Herschel Investigation of Cores and Filamentary Structures in the Perseus Molecular Cloud

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Research in Astronomy and Astrophysics 2022年第5期22卷 109-120页

作者： Chang Zhang Guo-Yin Zhang jin-zeng Li Xue-Mei Li National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China College of Physics Guizhou UniversityGuiyang 550025China

Cores and filamentary structures are the prime birthplaces of stars,and play key roles in the process of star *** advances in the methods of multi-scale source and filament extraction,and in making highresolution column density map from Herschel multi-wavelength observations enable us to detect the filamentary network structures in highly complex molecular cloud *** statistics for physical parameters shows that core mass strongly correlates with core dust temperature,and M/L strongly correlates with M/T,which is in line with the prediction of the blackbody radiation,and can be used to trace evolutionary sequence from unbound starless cores to robust prestellar *** column densities of the filamentary structures are clearly related with mass per unit length(M_(line)),but are uncorrelated by three orders ranging from~10^(20) to~10^(22) cm^(-2) with *** width at half maximum has a median value of 0.15 pc,which is consistent with the 0.1 pc typical inner width of the filamentary structures reported by previous *** find 70%of robust prestellar cores(135/199)embedded in supercritical filaments with M_(line),>16 M⊙pc^(-1),which implies that the gravitationally bound cores come from fragmentation of supercritical *** the basis of observational evidence that the probability distribution function with power-law distribution in the Perseus south is flatter than in the north,the number of young stellar objects in the south is significantly less than that in the north,and dust temperature is *** infer that the south region is more gravitationally bound than the north region.

关键词： star forming regions-molecular clouds-interstellar filaments