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An embedded electron current layer observed at the edge of the plasma sheet in the Earth’s magnetotail

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Earth and Planetary Physics 2025年第1期9卷 148-158页

作者： ChenChen Zhan RongSheng Wang QuanMing Lu san Lu XinMin Li Deep Space Exploration Laboratory/School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China Chinese Academy of Sciences(CAS)Center for Excellence in Comparative Planetology/CAS Key Laboratory of Geospace Environment/Anhui Mengcheng National Geophysical Observatory University of Science and Technology of ChinaHefei 230026China Collaborative Innovation Center of Astronautical Science and Technology Harbin 150001China

The formation of an embedded electron current sheet within the magnetotail plasma sheet has been poorly *** this article,we present an electron current layer detected at the edge of the magnetotail plasma *** ions were demagnetized inside the electron current layer,but the electrons were still frozen in with the magnetic field ***,this decoupling of ions and electrons gave rise to a strong Hall electric field,which could be the reason for the formation of the embedded thin current *** magnetized electrons,the absence of the nongyrotropic electron distribution,and negligible energy dissipation in the layer indicate that magnetic reconnection had not been triggered within the embedded thin current *** highly asymmetric plasma on the two sides of the current layer and low magnetic shear across it could suppress magnetic *** observations indicate that the embedded electric current layer,probably generated by the Hall electric field,even down to electron scale,is not a sufficient condition for magnetic reconnection.

关键词： magnetotail plasma sheet magnetic reconnection

Studies of the Intramolecular Aromatic-ring Stacking Interactions in the Ternary Platinum(Ⅱ) Complexes

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Chemical Research in Chinese Universities 2005年第1期21卷 8-11页

作者： sunhong-liang ResearchCenterofChemistry＆Analysis ZhejiangGongshangUniversityHangzhou310035P.R.China

The stability constants of some ternary mixed-ligand complexes, Pt(Phen)(CA)+, where Phen=1,10-phenanthroline and CA- =carboxylate, were determined by means of potentiometric pH titration in aqueous solutions(I=0.1 mol/L, KNO 3; 25 ℃), and the stability of them was compared with that of the corresponding binary complexes. It was revealed that the ternary complexes containing phenylalkane carboxylates ligands(PCA-) are much more stable than those formed with formate and acetate. The results indicate that there exist the intramolecular aromatic-ring interactions between the phenanthroline ring of Phen and the phenyl moiety of ligand PCA- in the ternary mixed-ligand Pt(Phen)(PCA)- complexes. The extent of the stacking interactions, which depends on the number of methylene groups between the phenyl moieties and the coordinated phenylalkane carboxylate groups, was calculated. The best-fitted stack was obtained for the complexes with 2-phenylacetate and 3-phenylpropionate as the ligands.

关键词： Platinum(Ⅱ) Mixed-ligand complex Aromatic-ring stacking Stability constant

Application of transmit diversity for improved robust watermarking

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Journal of Systems Engineering and Electronics 2004年第2期15卷 163-170页

作者： SunRui sunhong YaoTianren DepartmentofElectronicandInformationEngineering HuazhongUniversityofScienceandTechnologyWuhan430074P.R.China DepartmentofCommunicationEngineering WuhanUniversityWuhan430072P.R.China

Many common multimedia signal processing, including cropping, filtering, and perceptual coding, make watermark signal fading-like modification. A scheme that applies transmit diversity technique to improve robustness of digital watermarking is presented. First, the scheme decomposes the original image using wavelet pyramid algorithm and chooses the middle-frequency band for transmission channel that the watermark will be embedded into. Then the watermark is pseudo-randomly permuted. The scheme makes use of space-time coding and differential detection technique to embed and extract watermark. The extracting process has access to neither the original image nor channel state information. Experimental results demonstrate that the scheme improves the performance of robust watermarking.

关键词： digital watermark transmit diversity space-time coding differential detection wavelet transform.

Nonlinear Dynamical Symmetries of Some Two-Dimensional Quantum Systems

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Communications in Theoretical Physics 2004年第3X期42卷 379-384页

作者： RUANDong sunhong-Zhou DepartmentofPhysics TsinghuaUniversityBeijing100084China CenterofTheoreticalNuclearPhysics NationalLaboratoryofHeavyIonAcceleratorLanzhou730000China

In this paper nonlinear dynamical symmetries of three quantum systems are studied in detail, such as theKepler-Coulomb system and the isotropic harmonic oscillator in a two-dimensional curved space, and the generalizedpseudo-oscillators in the two-dimensional flat space. Their nonlinear spectrum generating algebras are shown to berelevant to polynomial angular momentum algebras.

关键词：非线性动力学对称多项式角动量代数开普勒-库仑系统谐波振荡器伪振荡器群论

Statistical multiresolution analysis in amplitude- frequency domain

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Science in China(Series F) 2004年第4期47卷 518-526页

作者： sunhong GUANBao HenriMaitre SchoolofElectronicInformation WuhanUniversityLIESMARSWuhan430072China DepartementdeTSI EcoleNationnaleSuperieuredesTelecommunication75013ParisFranceCorrespondenceshouldbeaddressedtoSunHong

A concept of statistical multiresolution analysis in amplitude-frequency domain is proposed, which is to employ the wavelet transform on the statistical character of a signal in amplitude domain. In terms of the theorem of generalized ergodicity, an algorithm to estimate the transform coefficients based on the amplitude statistical multiresolution analysis (AMA) is presented. The principle of applying the AMA to Synthetic Aperture Radar (SAR) image processing is described, and the good experimental results imply that the AMA is an efficient tool for processing of speckled signals modeled by the multiplicative noise.

关键词： statistical signal analysis multiresolution analysis SAR image processing discrete-amplitude signal processing.

Optimized algorithm for balancing clusters in wireless sensor networks

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第10期10卷 1404-1412页

作者： Mucheol KIM sunhong KIM Hyungjin BYUN School of Computer Science and Engineering Chung-Ang University 221Heuk seok-dongDongjak-guSeoul 156-756Korea

Wireless sensor networks consist of hundreds or thousands of sensor nodes that involve numerous restrictions in-cluding computation capability and battery *** control is an important issue for achieving a balanced placement of sensor *** clustering scheme is a widely known and efficient means of topology control for transmitting information to the base station in two *** automatic routing scheme of the self-organizing technique is another critical element of wireless sensor *** this paper we propose an optimal algorithm with cluster balance taken into consideration,and compare it with three well known and widely used approaches,i.e.,LEACH,MEER,and VAP-E,in performance *** results show that the proposed approach increases the overall network lifetime,indicating that the amount of energy required for com-munication to the base station will be reduced for locating an optimal cluster.

关键词： Wireless sensor networks Self-organizing sensor algorithm Clustering algorithm Optimization

Single Boson Realizations of the Higgs Algebra

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Communications in Theoretical Physics 2003年第1X期40卷 73-76页

作者： RUANDong WUChu sunhong-Zhou TheKeyLaboratoryofQuantumInformationandMeasurementsofMinistryofEducation TsinghuaUniversityBeijing100084China DepaxtmentofPhysics TsinghuaUniversityBeijing100084China InstituteofTheoreticalPhysics AcademiaSinicaBeijing100080China

We obtained for the Higgs algebra three kinds of single boson realizations such as the unitary Holstein-Primakoff-like realization, the non-unitary Dyson-like realization, and the unitary Villain-like realization. The corre-sponding similarity transformations between the Holstein-Primakoff-like realizations and the Dyson-like realizations are given.

关键词：希格斯介子代数非线性角动量代数玻色子 Higgs代数多项式角动量代数量子场论

Interleaver Design Method for Turbo Codes Based on Genetic Algorithm

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Wuhan University Journal of Natural Sciences 2004年第3期9卷 323-326页

作者： TanYing sunhong ZhouHuai-bei SchoolofElectronicInformation WuhanUniversityWuhan430072HubeiChina AdvancedResearchCenterforScienceandTechnology WuhanUniversityWuhan430072HubeiChina

This paper describes a new interleaver construction technique for turbo code. The technique searches as much as possible pseudo-random interleaving patterns under a certain condition using genetic algorithms(GAs). The new interleavers have the superiority of the S-random interleavers and this interleaver construction technique can reduce the time taken to generate pseudo-random interleaving patterns under a certain condition. The results obtained indicate that the new interleavers yield an equal to or better performance than the S-random interleavers. Compared to the S-random interleaver, this design requires a lower level of computational complexity. Key words interleaver - Turbo codes - genetic algorithm CLC number TN 911. 22 Foundation item: Supported by the National Natural Science Foundation of China (60372057) and the Key Open Laboratory on Information Science and Engineering of Railway Transportation Ministry of Beijing Jiaotong University of China (KLISAE-0103)Biography: Tan Ying (1963-), female, Associate professor, Ph. D, research direction: error control coding, analysis and design of wireless communication system.

关键词： interleaver Turbo codes genetic algorithm

Synthetic Aperture Radar Raw Signals Simulation of Extended Scenes

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Wuhan University Journal of Natural Sciences 2004年第3期9卷 327-331页

作者： SunJin-yao sunhong SchoolofElectronicInformation WuhanUniversityWuhan430072HubeiChina

A synthetic aperture radar (SAR) raw signal simulation algorithm for extended scenes is presented. This algorithm is based on the SAR two-dimensional system transform function (STF). To cope with range-variant nature of SAR STF and increase the speed of this algorithms, new formulas for range-variant phase corrections in range-Doppler (RD) domain are developed. In this way, many azimuth lines can be simulated with the same SAR STF. It only needs two-dimensional fast Fourier transform code and complex multiplications. Comparing with time-domain simulation algorithm, it is very simple and thus efficient. Simulation results have shown that this algorithm is accurate and efficient. Key words synthetic aperture radar - raw signal simulation - system transform function CLC number TP 751. 1 Foundation item: Supported by the National Natural Science Foundation of China (40376051)Biography: Sun Jin-yao (1967-), female, Ph. D. candidate, research direction: SAR image simulation and 3D recover for SAR image.

关键词： synthetic aperture radar raw signal simulation system transform function