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The fractal characteristic change in the Huanghe River Estuary due to the hydrodynamic conditions’variation

Acta Oceanologica Sinica 2003年第2期22卷 191-200页

作者： Jia Yonggang, Fu Yuanbin, Xu Guohui, Shan Hongxian, Cao Xueqing Environmental Engineering department, Ocean University of{1., qingdao 266003,{3. Environmental Engineering department Ocean University of China Qingdao 266003 China

The study area lies in the subaqueous delta, which came into being in 1.64 - 1.76. Oneoil-field road has been built for exploring petroleum to form a wave barrier. The hydrodynarnic conditions on the north side of the road are relatively violent, on the contrary the hydrodynarnic conditions on the south side of the road are nearly placid. This makes the study area a natural laboratory for studying the influence of the hydrodynarnic conditions on the fractal characteristics of the tidal flat. Selecting an area is named Case Ⅰ on the side of stronger hydrodynarnic activities and an area is named Case Ⅱ on the other side. Measuring the topography and sampling and analyzing the granulometrical composition, it is found that the hydrodynarnic conditions have fatal influence on the surface fractal dimensions and the granulometrical fractal dimensions of the area. In Case Ⅰ , which has strong hydrodynarnic conditions, the surface fractal dimensions are obviously larger than those of Case Ⅱ , and the granulometrical fractal dimensions are relatively smaller than those of Case Ⅱ , the surface fractal dimensions of Case Ⅰ decrease quickly with the increase of grid size; the granulometrical fractal dimensions are disperse, while the hydrodynarnic conditions of Case Ⅱ are just reverse. A sampling line and a core sampling on each side of the road are selected. It is found that on the south side of the road the granulometrical fractal dimensions vary regularly in the line and with the depth, the farther apart from the road, the smaller the fractal dimensions, and the deeper the sampling position the larger the fractal dimensions, while granulometrical fractal dimensions on the north side of the road have no such regularity pattern. The mechanism of the influence of the hydrodynarnic conditions on the fractal characteristics is discussed.

关键词： Tidal-flat hydrodynamic conditions surface fractal dimensions granulometrical fractal dimensions Huanghe River Estuary

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Spectral anomalies and spectral switches of partially coherent and polychromatic light diffracted at an aperture

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Science china({1.,Mechanics & Astronomy) 2004年第1期47卷 24-35页

作者： Lü Baida1. 3.& PAN Liuzhan1. 2 1. Institute of Laser {1. and Chemistry, Sichuan University, Chengdu 61.064, china 2. department of {1., Luoyang Normal College, Luoyang 471.22, china 3. State Key Laboratory of Laser Technology, Huazhong University of Science and Technology, Wuhan 43.074, china Correspondence should be addressed to L Baida (email: badalu@***) Received July 1., 2003 Institute of Laser physics and Chemistry Sichuan University Chengdu China State Key Laboratory of Laser Technology Huazhong University of Science and Technology Wuhan China department of {1. Luoyang Normal College Luoyang China

Based on the propagation theory of partially coherent light in the space-frequency domain, the anomalous spectral behavior and spectral switches in the far field of partially coherent and polychromatic light diffracted at an aperture are studied. It is shown that, as compared with spatially fully coherent and polychromatic light whose spectral anomalies are induced only by aperture diffraction, the spectral anomalies and spectral switches of partially coherent and polychromatic light depend on the aperture diffraction, spatial correlationβ and bandwidth of the original spectrum. Detailed numerical calculations are made to illustrate the behavior of spectral switches of partially coherent and polychromatic light, and the results for spatially fully coherent and polychromatic light are treated as a special case ofβ=1.and included in our theory.

关键词： spectral anomaly spectral switch partially coherent and polychromatic light far field aperture diffraction

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Synthesis of vertically aligned carbon nanotube arrays on silicon substrates

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Science china(Technological Sciences) 2004年第5期47卷 616-624页

作者： ZHENG Ruiting1. CHENG Guoan1. PENG Yibin1. 2, ZHAO Yong1. 3. LIU Huaping1.& LIANG Changlin1.1. Key Laboratory of Radiation Beam Technology and Materials Modification of Ministry of Education, {1. of Materials Science and Engineering, Beijing Normal University, Beijing 1.0875, china 2. School of Science, Civil Aviation University of china, Tianjin 3.03.0, china 3. department of physics, Nanchang University, Nanchang 3.0047, china Correspondence should be addressed to Zheng Ruiting Key Laboratory of Radiation Beam Technology and Materials Modification of Ministry of Education Department of Materials Science and Engineering Beijing Normal University Beijing China School of Science Civil Aviation University of China Tianjin China department of {1. Nanchang University Nanchang China

The growth of well-aligned carbon nanotube (CNT) arrays using a heat chemical vapor deposition system on silicon substrates is reported. The growth properties of CNT arrays are studied as a function of synthesis conditions. It is found that 750°C and 1. nm Fe film are suitable conditions for the growth of well-aligned CNT arrays. CNT arrays with a uniform diameter, thick tube wall and firm cohesion to the Si substrate can be grown for C2H2 concentration of 27%. Based on the experiment, the processes of improving the alignment of CNT arrays and cohesion between CNT arrays and Si substrates are discussed.

关键词： carbon nanotubes, vertically aligned, silicon substrate, chemical vapor deposition.

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Solving the input data in error correc-tion of optical fabrication by finite Fourier coefficient algorithm

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Science china(Technological Sciences) 2006年第1期49卷 50-60页

作者： CHENG Haobo1.2, SUN Guozheng3.& FENG Zhijing2 1. {1. of Optical Engineering, Beijing Institute of Technology, Beijing 1.0081. china 2. {1. of Precision Instruments and Mechanology, Tsinghua University, Beijing 1.0084, china 3. china North Industries Group Corporation, Beijing 1.0089, china department of Optical Engineering Beijing Institute of Technology Beijing China department of Precision Instruments and Mechanology Tsinghua University Beijing China china North Industries Group Corporation Beijing China

A free-form lens (FFL) is a special surface that is difficult to be fabricated. FFL are usually fabricated by computer-controlled optical surfacing (CCOS) technique. During CCOS, the material removal amount is determined by the unit removal function (URF) convoluting with the input data――the dwell time. When the removal amount and the URF are known, how to solve the input data involves the special algorithm――deconvolution. Usually, the input data are solved by virtue of low pass filter or iterative methods. However, an approximation solution would destroy the machining stability nec-essary to perform precisely CCOS. In this paper, to solve the input data, a new method that is based on the finite Fourier coefficient is put forward. It can give a continuous and accurate solution for fabricating choice. Several parameters are simulated, which influ-ence the process of CCOS, and evaluating on the effect of the method is also carried out. Experimental results verify that this method is suitable for guiding the manufacturing of high precision FFL.

关键词： optical fabrication, computer controlled optical surfacing, free-form lens, finite Fourier coefficient, error correction.

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Symmetries and exact solutions of discrete nonconservative systems

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Science china({1.,Mechanics & Astronomy) 2010年第9期53卷 1699-1706页

作者： FU JingLi1.LI XiaoWei2,LI ChaoRong1.ZHAO WeiJia3.& CHEN BenYong4 1.Institute of Mathematical {1.,Zhejiang Sci-Tech University,Hangzhou 3.001.,china 2 department of {1.,Shangqiu Normal University,Shangqiu 476000,china 3.department of Mathematics,qingdao University,qingdao 266071.china 4 Faculty of Mechanical Engineering & Automation,Zhejiang Sci-Tech University,Hangzhou 3.001.,china Institute of Mathematical physics Zhejiang Sci-Tech University Hangzhou China department of {1. Shangqiu Normal University Shangqiu China department of Mathematics Qingdao University Qingdao China Faculty of Mechanical Engineering & Automation Zhejiang Sci-Tech University Hangzhou China

Based on the property of the discrete model entirely inheriting the symmetry of the continuous system,we present a method to construct exact solutions with continuous groups of transformations in discrete nonconservative *** Noether's identity of the discrete nonconservative system is *** symmetric discrete Lagrangian and symmetric discrete nonconservative forces are defined for the *** quasi-extremal equations of discrete nonconservative systems are *** conserved quantities are derived with symmetries associated with the continuous *** have also found that the existence of the one-parameter symmetry group provides a reduction to a conserved quantity;but the existence of a two-parameter symmetry group makes it possible to obtain an exact solution for a discrete nonconservative *** examples are discussed to illustrate these results.

关键词： discrete nonconservative system symmetry conserved quantity quasi-extremal equation exact solution

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Ultrafast excitation relaxation in light-harvesting complex LH2 from *** 601

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Science china Chemistry 2004年第3期47卷 192-199页

作者： GUO Lijun1.2, LIU Yuan3. LIU Weimin2, GUO Junhua1. XU Chunhe3.& QIAN Shixiong2 1. School of physics and Information Optoelectronics, Henan University, Kaifeng 475001. china 2. physics {3., Fudan University, Shanghai 20043., china 3. Shanghai Institute of Plant Physiology, Chinese Academy of Sciences, Shanghai 20003., china School of physics and Information Optoelectronics Henan University Kaifeng China physics {1. Fudan University Shanghai China Shanghai Institute of Plant Physiology Chinese Academy of Sciences Shanghai China

The energy relaxation and kinetic evolution of transient spectra of bacteriochloro- phylls (BChls) in light-harvesting complex LH2 from Rb. sphaeroides 601.were investigated using femtosecond pump-probe technique. Upon 783.nm excitation, the energy at B800 BChls ex-periences an intramolecular redistribution with 0.3. ps time constant before transferring to B850 BChls. With tuning the excitation wavelength, the dynamical evolution of excited BChls was clearly observed, which indicates an obvious competition between the ground state bleaching and excited state absorption (ESA) of BChls involved and an isosbestic point near 81. nm, and also demonstrates that from the lower electronic excited state of B800 BChls to the higher exci-tonic state of B850 BChls is an efficient routine for energy transfer. The excitation energy in higher excitonic states of B850 BChls relaxes rapidly to the next lowest excitonic state by inter-conversion, delocalization to adjacent molecular, populating the lowest excitonic state and the change of molecular conformation.

关键词： photosynthesis, light-harvesting complex, energy transfer, ultrafast, dynamics, purple bacteria.

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Rare earth elements-rich phase and enriching mechanism in sediments from CC area, the Pacific Ocean

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Acta Oceanologica Sinica 2001年第2期20卷 209-214页

作者： Meng Xianwei, Chen Zhihua, Wang Xiangqin, Liu Na (1. First Institute of oceanography, State Oceanic Administration,{1., china 2. Key Lab. of Marine Science and Numerical Modelling, State Oceanic Administration,{1., china) First Institute of oceanography State Oceanic Administration Key Lab. of Marine Sci./Numerical Mo Qingdao 266003 China

Compared to North American shale composition (NASC), REE contents of sediments from the CC area in the Pacific Ocean are obviously high except that cerium has equal content to that of NASC. Three-valence rare earth elements were completely enriched in phosphate-phase and cerium in iron-phase. Rare earth elements in the sediments were originally derived from seawater. During lithi- genic and minerogenic processes of metalliferous nodules, three-valence rare earth elements in sediments mobilized and incorporated into sediments as authigenous biogenic-apatite, while cerium had change from Ce3. to Ce4+ and directly precipitated from seawater and entered metalliferous nodules and caused Ce anomalies in REE pattern in sediments.

关键词： CC area of the Pacific Ocean sediments rare earth elements REE- rich phase enriching mechanism

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Parabolic equation of the m-Laplacian with nonlinear boundary condition

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Chinese Science Bulletin 1998年第11期43卷 905-908页

作者： WANG Shu+ 1. 2, WANG Mingxin 3. XIE Chunhong 1.1. {1. of Mathematics, Nanjing University, Nanjing 21.093. china 2. {1. of Mathematics, Henan University, Kaifeng 475001. china 3. {1. of Applied Mathematics, Southeast University, department of Mathernntics Nanjing University Nanjing China department of Mathematics Henan University Kaifeng China department of Applied Mathematics Southeast University Nanjing China

The existence and nonexistence of global positive weak solutions of parabolic equation of the m-Laplician with nonlinear boundary condition are dealt with. The necessary and sufficient conditions on the existence of a... 详细信息

关键词： nonlinear boundary condition parabolic equation of m-Laplacian global solution blow-up.

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X-ray spectra induced by ^(1.9)Xe^(q+) impacting the metal surface

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Science china({1.,Mechanics & Astronomy) 2008年第1期51卷 82-89页

作者： ZHANG XiaoAn 1.2 ,XIAO GuoQing 1.,YANG ZhiHu 1.,CHEN XiMeng 3.,ZHAO YongTao 1., LI FuLi 4 ,WANG Li 1.2 ,CUI Ying 3.,ZHANG HongQiang 3.&ZHAN WenLong 1.1.nstitute of Modern physics,Chinese Academy of Sciences,Lanzhou 73.000,china 2department of physics,Xianyang Normal University,Xianyang 71.000,china 3.2} of Modern physics,Lanzhou University,Lanzhou 73.000,china 4department of Applied physics,Xi’an Jiaotong University,Xi’an 71.049,china Institute of Modern physics Chinese Academy of Sciences Lanzhou China department of {1. Xianyang Normal University Xianyang China department of Modern {1. Lanzhou University Lanzhou China department of Applied {1. Xi’an Jiaotong University China

Using the slow highly charged ions 1.9 Xe q+ (q=25,26,27;initial kinetic T0≤4.65 keV/a.u.)to impact Au surface,the Au atomic Mαcharacteristic X-ray spectrum is *** result shows that as long as the charge state of projectile is high enough,the heavy atomic characteristic X-ray can be effectively excited even though the incident beam is very weak(nA magnitude),and the X-ray yield per ion is in the order of 1.-8and increases with the kinetic energy and potential energy of *** measuring the Au Mα-X-ray spectra,Au atomic N-level lifetime is estimated at about 1.3.×1.-1.s based on Heisenberg uncertainty relation.

关键词： slow highly charged ions characteristic X-ray level lifetime

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Bionic Design and Finite Element Analysis of Elbow in Ice Transportation Cooling System

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Journal of Bionic Engineering 2010年第3期7卷 301-306页

作者： Dejun Miao~(1.2), Xiuhua Sui~3. Linjing Xiao~3.1. Key Laboratory of Mine Hazard Prevention and Control (Ministry of Education, china), Shandong University of Science and Technology, qingdao 26651., P. R. china 2. School of Architecture, Tsinghua University, Beijing 1.0084, P. R. china 3. College of Mechanical and Electronic Engineering, Shandong University of Science and Technology, qingdao 26651., P. R. china Key Laboratory of Mine Hazard Prevention and Control (Ministry of Education China) Shandong University of Science and Technology Qingdao P. R. China School of Architecture Tsinghua University Beijing P. R. China College of Mechanical and Electronic Engineering Shandong University of Science and Technology Qingdao P. R. China

With the increase in mining depth, mine heat harm has appeared to be more prominent. The mine heat harm could be resolvedor reduced by ice refrigeration. Thus, ice transportation through pipeline becomes a critical problem; typically flowresistance occurs in the elbow. In the present study, according to the analysis of the surface morphology of fish scale, abiomimetic functional surface structure for the interior wall of elbow is designed. Based on the theory of liquid-solid two phaseflow, a CFD numerical simulation of ice-water mixture flowing through the elbow is carried out using finite element *** experiments of pressure drop and flow resistance for both bionic and common elbows are conducted to test theeffect of the bionic elbow on flow resistance reduction. It is found that with the increase in the ice mass fraction in the ice-watermixture, the effect of bionic elbow on resistance reduction becomes more obvious.

关键词： bionic elbow two phase flow ice transportation flow resistance reduction pressure loss

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