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science china(Technological sciences) 2009年第7期52卷 1919-1922页

作者： LI Qiang1,2.1 school of physics {2. and technology, Xinjiang University, Urumqi 830046, china 2.Department of physics, The Chinese University of HongKong, Shatin N.T., HongKong, china school of physics {2. and technology Xinjiang University Department of physics The Chinese University of HongKong Shatin N.T.

Nanostructured Fe40Ni40P14B6 alloy ingots of 3―5 mm in diameter could be synthesized by a metastable liquid state spinodal decomposition method. For undercooling T> 2.0 K, the microstructure of the undercooled specimen had exhibited liquid state spinodal decomposition in the undercooled liquid state. The microstructure could be described as two intertwining networks with small grains dispersed in them. For undercooling T>2.0 K, the overall microstructure of the specimen changed into a granular morphology. The average grain sizes of the small and large grains are 30 nm and 80 nm, respectively. These prepared samples are soft magnets with saturation magnetization Bs 0.744 T.

关键词： nanomaterials magnetic materials solidification bulk nanostructured alloy Fe40Ni40P14B6 metastable liquid spinodal decomposition

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

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science china({2.,Mechanics & Astronomy) 2004年第1期47卷 24-35页

作者： Lü Baida1, 3 & PAN Liuzhan1, 2.1. Institute of Laser physics and Chemistry, Sichuan University, Chengdu 610064, china 2. Department of physics, Luoyang Normal College, Luoyang 47102., china 3. State Key Laboratory of Laser technology, Huazhong University of science and technology, Wuhan 430074, china Correspondence should be addressed to L Baida (email: badalu@***) Received July 10, 2.03 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 physics 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

CHARACTERISTICS OF THE INTERANNUAL AND INTERDECADAL TIMESCALES OF EVAPORATION IN NORTHERN china IN THE RECENT 115 YEARS

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Journal of Hydrodynamics 2006年第5期18卷 593-596页

作者： RONG Yan-shu TU Qi-pu DUAN Li-yao College of Water Resources and Environment Hohai University Nanjing 210098 China Tianjin Institute of Meteorological Science Tianjin 300074 China Tianjin Institute of Meteorological science Tianjin 300074 China nanjing University of information {2. and technology Nanjing 210044 China Tianjin Climate Centre Tianjin 300074 China

Evaporation plays an important role in water balance on the land surface. In Northern china, the evaporation series of the recent 115 years was reconstructed on the basis of Yhornthwaite evaporation formula. The characteristics of the reconstructed series were analyzed using 10-year running mean filter, power spectrum method, and running t-text of abrupt changes on the paper. The results showed that there were remarkable interannual fluctuations with timescales of about quasi-8-year, 3-4-year, and quasi-2.year, and interdecadal oscillations with timescales of 57.5-year, quasi-2.-year, and l l.5-year. Meanwhile, the abrupt changes of the evaporation series were also of interdecadal timescale. Either interannual fluctuations or interdecadal oscillations of evaporation were closely related to variations in air temperatures and precipitation.

关键词： reconstructed evaporation series interannual timescale interdecadal timescale Northern china

Electron dynamics in collisionless magnetic reconnection with a PIC simulation

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Chinese science Bulletin 2009年第3期54卷 456-460页

作者： GUO Jun1,2.1 school of mathematics and {2., Qingdao University of science and technology, Qingdao 2.6042. china 2.State Key Laboratory of Space Weather, Chinese Academy of sciences, Beijing 100080, china school of mathematics and {2. Qingdao University of Science and Technology Qingdao China State Key Laboratory of Space Weather Chinese Academy of Sciences Beijing China

Two-dimensional particle-in-cell (PIC) simulation is used to investigate electron dynamics in colli- sionless magnetic reconnection, and the proton/electron mass ratio is taken to be mi /me = 2.6. The results show that the presence of a strong initial guide field will change the direction of the electron flow. The electron density cavities and the parallel electric field can be found in the electron inflow re- gion along the separatrix, and the electron inflow and density cavities only appear in the second and fourth quadrants. What is different from the results with a smaller mass ratio is that new structures appear in the diffusion region near the X line: (1) Narrow regions of density enhancement and density cavities can be found synchronously in this region; and (2. corresponding to the electron density changes near the X line, the strong parallel electric fields are found to occur in the first and third quadrants. These electric fields perhaps play a more important role in acceleration and heating electrons than those fields located in the density cavities.

关键词： PIC模仿磁链接导向场电子动力学

Rose solutions with three petals for planar 4-body problems

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science china {2. 2010年第12期53卷 3085-3094页

作者： DENG ChunHua 1,2., ZHANG ShiQing 1, & ZHOU Qing 3 1 Yangtze Center of mathematics and College of mathematics, Sichuan University, Chengdu 610064, {2. 2.Faculty of mathematics and physics, Huaiyin Institute of technology, Huai’an 2.3001, {2. 3 Department of mathematics, East {2. Normal University, Shanghai 2.0062. {2. Yangtze Center of mathematics and College of mathematics Sichuan University Faculty of mathematics and physics Huaiyin Institute of Technology Department of mathematics East China Normal University

For planar Newtonian 4-body problems with equal masses, we use variational methods to prove the existence of a non-collision periodic choreography solution such that all bodies move on a rose-type curve with three pet... 详细信息

关键词： 4-body problems with Newtonian potentials rose solutions with three petals winding numbers variational minimization methods

Image denoising and deblurring: non-convex regularization, inverse diffusion and shock filter

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science china({2. sciences) 2011年第6期54卷 1184-1198页

作者： FU ShuJun 1,2.3 , ZHANG CaiMing 2.& TAI XueCheng 3,4 1 school of mathematics, Shandong University, Jinan 2.0100, {2. 2.school of Computer science and technology, Shandong University, Jinan 2.0101, {2. 3.school of Physical and Mathematical sciences, Nanyang Technological University, Singapore 639798, Singapore 4 Department of mathematics, University of Bergen, Bergen 5008, Norway school of mathematics Shandong University school of Computer science and {2. Shandong University school of Physical and Mathematical sciences Nanyang Technological University Department of mathematics University of Bergen

A large number of applications in image processing and computer vision depend on image quality. In this paper, main concerns are image denoising and deblurring simultaneously in a restoration task by three types of methodologies: non-convex regularization, inverse diffusion and shock filter. We discuss their relations in the context of image deblurring: the inverse diffusion implied by the non-convex regularization, and the superior ability of deblurring edge of the shock filter to that of the inverse diffusion, both in 1D and 2. cases. Finally, we propose a region-based adaptive anisotropic diffusion with shock filter method, which shows advantages of deblurring edges, denoising and smoothing contours in experiments, compared with some related methods. Therein an idea of "divide and rule" is introduced.

关键词： image denoising image deblurring non-convex regularization inverse diffusion shock filter adaptive anisotropic diffusion

Research on resolution between multi-component LFM signals in the fractional Fourier domain

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science china({2. sciences) 2012年第6期55卷 1301-1312页

作者： LIU Feng 1,XU HuiFa 1,2.TAO Ran 3 & WANG Yue 3 1 Department of Electronic and information Engineering,Naval Aeronautical Engineering Institute,Yantai 2.4001,china 2.The 94362.th Unit of People's Liberation Army,Qingdao 2.6111,china 3.school of information science and technology,Beijing Institute of technology,Beijing 100081,china Department of Electronic and information Engineering Naval Aeronautical Engineering Institute The 94362.h Unit of People"s Liberation Army school of information {2. and technology Beijing Institute of Technology

When the initial frequencies and chirp rates of multi-component linear frequency modulation (LFM or chirp) signals are close,the signals may not be distinguished in the fractional Fourier domain (FRFD).Consequently,some signals cannot be *** this paper,first,the spectral distribution characteristics of a continuous LFM signal in the FRFD are analyzed,and then the spectral distribution characteristics of a LFM signal in the discrete FRFD are ***,the critical resolution distance between the peaks of two LFM signals in the FRFD is deduced,and the relationship between the dimensional normalization parameter and the distance between two LFM signals in the FRFD is also *** is discovered that selecting a proper dimensional normalization parameter can increase the ***,a method to select the parameter is proposed,which can improve the resolution ability of the fractional Fourier transform (FRFT).Its effectiveness is verified by simulation results.

关键词： fractional Fourier transform LFM signal signal resolution

Synchronization of Digital Chaos in Secure Communication Systems

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Journal of University of science and technology Beijing 2001年第4期8卷 299-305页

作者： Geng Zhao, Deling Zheng, ShaojunHuang 1)College of Electric science and technology Beijing. Beijing 100070, {2. 2.information Engineering school, University of science and technology Beijing. Beijing 100083, {2. College of Electric science and technology Beijing Beijing 100070 China information Engineering school University of Science and Technology Beijing Beijing 100083 China

The theories of synchronization based on secure communications using digital chaos are presented. A new synchronous method-cycles-interval Pulse drive is developed and realized. Experimental results show it is available, and in order to reduce synchronous noise, a method using model references solves the ratio of signal power to noise power, so the secure communication system can be realized.

关键词： digital chaotic synchronization cycles-interval pulses drive synchronous noise model reference

Synthetical Control of AGC/LPC System Based on Neural Networks Internal Model Control

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Journal of University of science and technology Beijing 2001年第1期8卷 75-77页

作者： Hu He, Xiaodong Luan, Yikang Sun information Engineering school, University of {2. and technology Beijing, Beijing 100083, china sl.ap-hop-paris.fr

One synthetical control method of AGC/LPC system based on intelligence control theory-neural networks internal model control method is presented. Genetic algorithm (GA) is applied to optimize the parameters of the neu... 详细信息

关键词： hot strip rolling AGC looper neural networks internal model control GA

H~∞ Theory and its Application to the Position of Rolling Mill Control System

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International Journal of Minerals,Metallurgy and Materials 1999年第3期13卷 230-233页

作者： Jie Dong Chaonan Tong Kaixiang Peng(information Engineering school, University of {2. and technology Beijing, Beijing 100083, china) information Engineering school University of Science and Technology Beijing Beijing 100083 China

The controller designed according to classical or modern control theory will not satisfy the performance requirements when the controlled object in industrial field can not be described by exact mathematical model or the disturbance of the controlled system. In order to make the controlled system stable and having good performance, H∞ control theory was put forward to solve this practical problem. Taking the position of a rolling mill as the controlled object, it was rectified by optimal engineering way. Then, three different plans were put forward according to Bang-Bang control, LQ control and H∞ control, respectively. The result of the simulation shows that the controller designed according to H∞ method whose robust performance and ability to restrain colors disturbance is satisfactory.

关键词： position control H~∞ control LQ control Bang-Bang controll