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Complex transient dynamics of hidden attractors in a simple 4D system

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Chinese Physics B 2015年第5期24卷 270-274页

作者：党小宇李春彪包伯成武花干 college of Electronic and Information engineering Nanjing University of Aeronautics and Astronautics School of Electronic & Information engineering Nanjing University of Information Science & Technology School of Information Science and engineering Changzhou University School of Electronic and Optical engineering Nanjing University of Science and Technology

A simple four-dimensional system with only one control parameter is proposed in this paper. The novel system has a line or no equilibrium for the global control parameter and exhibits complex transient transition behaviors of hyperchaotic attractors, periodic orbits, and unstable sinks. Especially, for the nonzero-valued control parameter, there exists no equilibrium in the proposed system, leading to the formation of various hidden attractors with complex transient dynamics. The research results indicate that the dynamics of the system shows weak chaotic robustness and depends greatly on the initial states.

关键词： transient dynamics hidden attractor equilibrium

A SEMI-ANALYTICAL AND SEMI-NUMERICAL METHOD FOR SOLVING 2-D SOUND-STRUCTURE INTERACTION PROBLEMS

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Acta Mechanica Solida Sinica 2003年第2期16卷 116-126页

作者： Xiang Yu Huang Yuying (college of civil engineering and Mechanics,Huazhong university of Science and technology,Wuhan 430074,china) collegeofcivilengineeringandMechanics HuazhongUniversityofScienceandTechnologyWuhan430074China

Based on the transfer matrix method and the virtual source simulation technique, this paper proposes a novel semi-analytical and semi-numerical method for solving 2-D sound- structure interaction problems under a harmonic *** any integration segment, as long as its length is small enough,along the circumferential curvilinear coordinate,the non- homogeneous matrix differential equation of an elastic ring of complex geometrical shape can be rewritten in terms of the homogeneous one by the method of extended homogeneous capacity proposed in this *** the exterior fluid domain,the multi-circular virtual source simulation technique is *** source density distributed on each virtual circular curve may be ex- panded as the Fourier's *** with the inverse fast Fourier transformation,a higher accuracy and efficiency method for solving 2-D exterior Helmholtz's problems is presented in this *** the aspect of solution to the coupling equations,the state vectors of elastic ring induced by the given harmonic excitation and generalized forces of coefficients of the Fourier series can be obtained respectively by using a high precision integration scheme combined with the method of extended homogeneous capacity put forward in this *** to the superposition princi- ple and compatibility conditions at the interface between the elastic ring and fluid,the algebraic equation of system can be directly constructed by using the least square *** of acoustic radiation from two typical fluid-loaded elastic rings under a harmonic concentrated force are *** results show that the method proposed is more efficient than the mixed FE-BE method in common use.

关键词： sound-structure interaction acoustic radiatlon multi-circular virtual source simulation technique transfer matrix method inverse fast Fourier transformation semi-analytical and semi-numerical method

Interhemispheric atmospheric mass oscillation and its relation to interannual variations of the Asian monsoon in boreal summer

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Science china Earth Sciences 2010年第9期53卷 1343-1350页

作者： LU ChuHan, GUAN ZhaoYong & CAI JiaXi Key Laboratory of Meteorological Disaster of Ministry of Education and college of Atmospheric Sciences, nanjing university of Information Science & technology, nanjing 210044, china 1. Key Laboratory of Meteorological Disaster of Ministry of Education and college of Atmospheric Sciences Nanjing University of Information Science & Technology Nanjing 210044 China

Using NCEP/NCAR reanalysis and precipitation records of Chinese stations, we have investigated the relationship of interhemispheric oscillation of air mass (IHO) with global lower-level circulation and monsoon anomalies in boreal summer. Our results show that the summer IHO explains a greater portion of variance in the abnormal distribution of atmospheric mass over 30°S-60°N as well as the Antarctic. The IHO strongly correlates to the variations of sea level pressure (SLP) in these regions. It is shown that IHO has some influences on both atmospheric mass transports and water vapor fluxes over 30°S-60°N in association with three anomalous cyclonic circulations over land areas of the eastern hemisphere, which is in close relation to the changes in summer monsoon intensity in eastern Asia and western Africa. Composites of summer rainfall anomalies in china for high and low IHO-index years indicate that the eastern Asian summer monsoon is more intense, with positive precipitation anomaly centers in northern and northeastern parts of china, as opposed to the negative center over the mid-lower reaches of the Yangtze River (MLRYR) in stronger IHO years. In weak IHO years, a feeble summer monsoon appears in eastern Asia, leading to positive center of precipitation anomalies displaced into the MLRYR. Furthermore, a teleconnection in wind fields between the western African and eastern Asian monsoon regions was observed in the middle and higher troposphere in the scenario of IHO. The anomalous cyclonic (anticyclonic) circulations along the path of this Africa-East Asia teleconnection were found to be just over the diabatic heating (cooling) centers, suggesting that diabatic forcings are responsible for the formation of this Africa-East Asia teleconnection.

关键词： interhemispheric oscillation Asian monsoon precipitation china boreal summer

A two-dimensional study on natural convection and heat transfer in the enclosure with heat transfer and radiation coupled in natural convection

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Science china(Technological Sciences) 2010年第4期53卷 991-999页

作者： ZHAN NaiYan1,2,YANG Mo1 & XU PeiWei2 1 college of Power engineering,university of Shanghai for Science and technology,Shanghiai 200093,china 2 Department of Environmental engineering,Jilin Architectural and civil engineering Institute,Changchun 130021,china 1. college of Power engineering University of Shanghai for Science and Technology Shanghiai 200093 China2. Department of Environmental Engineering Jilin Architectural and Civil Engineering Institute Changchun 130021 China

Numerical investigation using SIMPLE algorithm with QUICK scheme for natural convection and heat transfer in the enclosure bounded by a solid wall and with heat transfer and radiation coupled in natural convection has been *** various parameters are:Rayleigh number(from 103 to 105),dimensionless conductivity of bounding wall(from 0 to 100),dimensionless wall thickness(from 0 to 0.6) and radiation emissivity of all surfaces(from 0 to 1).The results suggest that flow and heat transfer are influenced by *** is a dominant action on flow and heat *** increase of the thermal conductivity of wall,flow and heat transfer turn *** temperature distribution changes *** the thermal conductivity of wall is over a certain critical number,the increasing trend of flow and heat transfer may *** increase of enclosure wall thickness,flow and heat transfer turn *** the enclosure wall thickness is over a certain critical number,the flow and heat transfer will turn slow.

关键词： conduction natural convection radiation couple numerical simulation

Microstructure and formation mechanism of twins of laths of austenite with high nitrogen

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Science china(Technological Sciences) 2007年第6期50卷 755-764页

作者： WU CuiLan1,2 & LUO ChengPing2 1 Center for High Resolution Electron Microscopy, college of Materials Science and engineering, Hunan university, Changsha 410082, china 2.college of Mechanical engineering, South china university of technology, Guangzhou 510641, china 1. Center for High Resolution Electron Microscopy College of Materials Science and Engineering Hunan University Changsha 410082 China 2. college of Mechanical engineering South China University of Technology Guangzhou 510641 China

The microstructure of composite diffusion layer of the nitrided and chromized 0.2% carbon steel is investigated using TEM and EDS. It is found that laths of austenite with high nitrogen (γ N) precipitate from α-ferrite matrix in the deeper zone of the diffusion layer. These γ N laths are all twins, with their {111} twinning planes parallel to the lath axis, thus forming a characteristic "back-to-back" morphology. There are two types of γN lath. The first is a genuinely {111} twin, and γ N and α keep the accurate K-S relationship, and each γ N and α form a sharp and smooth γ N/α inter- face of {335}γN//{341}α, namely habit plane {335}fcc. The second is a pseudo-twin, with micro-twins {111} or faults formed within the two twin components. Localized lattice deformation (relaxation) seems to have occurred at the interfaces of the second type of γ N due to the formation of micro-twins or faults within the twin components. These micro-twins or faults make the orientation relationship (OR) between each of the γN and the α-matrix deviate from the accurate K-S OR, and the OR between two γ N twin components deviate from the genuine {111} twin relation- ship. In addition, the γ N/α interface of the second type of γ N is not as sharp or smooth as that of the first one.

关键词： austenite containing nitrogen, twins, steel 20, nitriding, composite chromizing

PROPERTY AND METALLOGENIC CHARACTERISTICS OF ALKALI-RICH PORPHYRY IN WESTERN MARGIN OF YANGTZE PLATFORM

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Journal of Central South university 1998年第2期10卷 57-60页

作者： Hu Xiangzhao (college of Resources, Environment and civil engineering,Central South university of technology, Changsha 410083, china) college of Resources Environment and Civil Engineering Central South University of Technology Changsha 410083 China

The age of alkali rich porphyries in the western margin of Yangtze Platform is 30—50 Ma; the minerals mainly are orthoclase, quartz, plagioclase; the chemical composition is alkali rich [(K 2O+Na 2O)>8%],high potash[(K 2O+Na 2O)=5.09%-8.30%]; the content of  REE  is relatively low, LREE is concentrated, without anomaly of europium; the average initial ratio of 87 Sr/ 86 Sr is 0.7073; the value of δ 34 S similar to that of the meteoritic sulfur; the ratio of Pb isotope corresponds to that of upper mantle; metallogenic types belong to Cu, Mo, Au, Ag, Pb, Zn polymetal mineralization and rare, rare earth metal mineralization.

关键词： petrology geochemistry alkali rich porphyry metallogenic characteristics

Preparation of Material Surface Structure Similarto Hydrophobic Structure of Lotus Leaf

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Journal of Wuhan university of technology(Materials Science) 2008年第4期23卷 513-517页

作者： CAO Feng GUAN Zisheng LI Dongxu college of Material Science and engineering Nanjing University of Technology Nanjing 210009 China

Nano/micro replication, a technique widely applied in the microelectronics field, was introduced to prepare the hydrophobic bionics microstructure on material surface. Poly（vinyl alcohol）（PVA） and polystyrene （PS） moulds of the mastoid microstructure on lotus leaf surface were prepared respectively by the nano/micro replication technology. And poly（dimethylsiloxane）（PDMS） replicas with the mastoid-like microstructure were prepared from these two kinds of polymer moulds. Scanning electronic microscope （SEM） was employed to investigate the morphology and microstructures on moulds and replicas. Both the static and dynamic contact angles between water droplet and PDMS replicas＇ surface were also measured. As a result, similar microstructure can be observed clearly on the surface of PDMS replicas and the static contact angle on PDMS replicas was enhanced dramatically by the existence of these microstructures.

关键词： hydrophobic bionics surface structure nano/micro replication

Thermal Conductivity and Heat Transfer Coefficient of Concrete

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Journal of Wuhan university of technology(Materials Science) 2011年第4期26卷 791-796页

作者：郭利霞 North china university of Water Resources and Electric Power

A very simple model for predicting thermal conductivity based on its definiensis was presented. The thermal conductivity obtained using the model provided a good coincidence to the investigations performed by other authors. The heat transfer coefficient was determined by inverse analysis using the temperature measurements. From experimental results, it is noted that heat transfer coefficient increases with the increase of wind velocity and relative humidity, a prediction equation on heat transfer coefficient about wind velocity and relative humidity is given.

关键词： thermal conductivity heat transfer coefficient relative humidity wind velocity

Kinetics analysis of volume phase transition of intelligent neutral thermo-sensitive hydrogels

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Science china(Physics,Mechanics & Astronomy) 2008年第5期51卷 532-540页

作者： WANG XiaoGui1 & LI YiQuan2 1 college of Mechanical engineering,Zhejiang university of technology,Hangzhou 310032,china 2 School of Mechanical & Electronic engineering,Changchun university of Science and technology,Changchun 130022,china 1. college of Mechanical engineering Zhejiang University of Technology Hangzhou 310032 China 2. School of Mechanical & Electronic engineering Changchun University of Science and Technology Changchun 130022 China

In this work,utilizing the first law of thermodynamics and the Flory mean-field theory,the kinetic deformation studies concerning the volume phase transition of the neutral thermo-sensitive hydrogels were performed *** hydrogel was assumed as a biphasic mixture medium in the framework of the continuum mixture *** the energy conservation of the thermodynamics system of the hydrogel,the governing equations for the kinetics of the nonlinear large deforma-tion were *** explicit analytical expressions of the effective stress tensor and the chemical potential of the fluid of the thermo-sensitive hydrogel PNIPA were also obtained from the Helmholtz free energy,which can model the steady-static volume phase transition quantitatively.

关键词： thermo-sensitive hydrogel volume phase transition effective stress energy conservation