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Fast Position and Velocity Determination for Pulsar Navigation Using NML and LSM

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Chinese Journal of Electronics 2017年第6期26卷 1325-1329页

作者： LIU jin WU jin XIONG ling FANG Jiancheng LIU Gang College of Information Science and Engineering Wuhan University of Science and Technology School of Instrumentation Science and Opto-electronics Engineering Beihang University

To reduce the computational cost, a Fast position and velocity joint determination(FPVD) method based on the Near-maximum likelihood(NML) and the Least square method(LSM) is proposed for X-ray pulsar navigation. Considering the fact that the Doppler effects caused by the velocity of the spacecraft alters the X-ray pulse Time-of-arrival(TOA), we adopt the NML to obtain multi-TOAs, and then utilize the LSM to estimate the variation of TOAs instead of the pulsar profile distortion adopted by the Maximum-likelihood(ML) estimation method. Finally, according to the variation value and TOAs, the position and velocity information of the spacecraft are calculated. The simulation results have demonstrated that the FPVD method is far faster than the ML estimation method, and its accuracy approaches the CramerRao lower bound(CRLB).

关键词： Velocity determination Pulsar Maximum likelihood Least square method

Intensity Correlation Function of a Single-Mode Laser Driven by Colored Cross-Correlation Noises in Modulation of a Bias Signal

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Communications in Theoretical Physics 2005年第4期43卷 666-670页

作者： HANLi-Bo CAOLi YANGHong-quan WUDa-jin StateKeyLaboratoryofLaserTechnology HuazhongUniversityofScienceandTechnologyWuhan430074China／／DepartmentofPhysicsYangtzeUniversityJingzhou434020China StateKeyLaboratoryofLaserTechnology HuazhongUniversityofScienceandTechnologyWuhan430074China／／CCAST（WorldLaboratory）Beijing100080China DepartmentofPhysics YangtzeUniversityJingzhou434020China CCAST（WorldLaboratory） Beijing100080China／／DepartmentofPhysicsHuazhongUniversityofScienceandTechnologyWuhan430074China

By using the linear approximation method, the intensity correlation function is calculated for a single-mode laser modulated by a bias signal and driven by colored pump and quantum noises with colored cross-correlation. We found that, when the correlation time between the two noises is very short, the behavior of the intensity correlation function versus the time, in addition to decreasing monotonously, also exhibits several cases, such as one maximum, one minimum, and two extrema. When the correlation time between the two noises is very long, the behavior of the intensity correlation function exhibits oscillation and the envelope is similar to the case of short cross-correlation time.

关键词： linear approximation method intensity correlation function bias signal modulation oscillation

Additive Maps Preserving Similarity of Operators on Banach Spaces

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Acta Mathematica Sinica,English Series 2006年第1期22卷 179-186页

作者： jin Chuan HOU Xiu ling ZHANG Department of Mathematics Shanxi Teachers University Linfen 041004 P R. China

Let X be an infinite-dimensional complex Banach space and denote by B（X） the algebra of all bounded linear operators acting on X. It is shown that a surjective additive map Φ from B（X） onto itself preserves similarity in both directions if and only if there exist a scalar c, a bounded invertible linear or conjugate linear operator A and a similarity invariant additive functional ψ on B（X） such that either Φ（T） = cATA^-1 ＋ ψ（T）I for all T, or Φ（T） = cAT＊A^-1 ＋ ψ（T）I for all T. In the case where X has infinite multiplicity, in particular, when X is an infinite-dimensional Hilbert space, the above similarity invariant additive functional ψ is always zero.

关键词： Additive maps on operator algebras Similarity of operators Banach spaces

Hawking Radiation of Charged Particles via Tunneling from a Cylindrically Symmetric Black Hole in Anti-de Sitter Space-Time

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Communications in Theoretical Physics 2006年第4X期46卷 643-646页

作者： YANG Shu-Zheng JIANG Qing-quan LI Hui-ling Institute of Theoretical Physics China West Normal University Nanchong 637002 China

Applying Parikh-Wilzcek＇s semi-classical quantum tunneling model, we study the Hawking radiation of charged particles as tunneling from the event horizon of a cylindrically symmetric black hole in anti-de Sitter space-time. The derived result shows that the tunneling rate of charged particles is related to the change of Bekenstein-Hawking entropy and that the radiation spectrum is not strictly pure thermal after taking the black hole background dynamical and self-gravitation interaction into account, but is consistent with the underlying unitary theory.

关键词： cylindrically symmetric black hole Bekenstein-Hawking entropy energy conservation charge conservation tunneling rate

Synthesis of Coumarin-functionalized Calix[4]arene and Selective Recognition for L-Tryptophan

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Chinese Chemical Letters 2006年第5期17卷 575-577页

作者： Jian quan LU Li ZHANG Ting quan SUN Gui Xiang WANG ling Yan WU Hubei Key Laboratory of Bioanalytical Technique Hubei Normal University Huangshi 435002

5,11,17,23-Tetra-tert-butyl-25, 27-bis（7＇-methoxycoumarin-3＇-methyloxy）-26, 28-dihydroxycalix[4]arene was synthesized and characterized. The derivative could recognize L-tryptophan with a 1：1 complexing ratio and an apparent equilibrium constant of 111 L mol^-1 in DMF acetonitrile as solvent by UV-visible and fluorescent spectrophotometry.

关键词： Calixarene synthesis recognition L-tryptophan.

quantum Tunneling Radiation of Reissner-Nordstrom de Sitter Black Hole with a Global Monopole

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Communications in Theoretical Physics 2006年第3期45卷 457-460页

作者： JIANG Qing-quan YANG Shu-Zheng LI Hui-ling Institute of Theoretical Physics West China Normal University Nanchong 637002 China

Applying Parikh＇s quantum tunneling model, we study the quantum tunneling radiation of Reissne- Nordstrom de Sitter black hole with a global monopole. The result shows that the tunneling rates at the event horizon and the cosmic horizon are related to Bekenstein-Hawking entropy if we take the energy conservation into consideration, and the true radiate spectrum is not precisely thermal.

关键词： Reissner-Nordstrom de Sitter black hole global monopole energy conservation tunneling rate

Mineralogy of the otoliths of naked carp Gymnocypris przewalskii (Kessler) from Lake Qinghai and its Sr/Ca potential implications for migratory pattern

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Science China Earth Sciences 2012年第6期55卷 983-990页

作者： ZHOU ling jin ZhangDong LI FuChun State Key Laboratory of＇Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi＇an 710075 China Graduate University of Chinese Academy of Sciences Beijing 100049 China College of Resources and Environmental Sciences Nanjing Agricultural University Nanjing 210095 China

Otoliths are biogenic carbonate minerals whose microstructure and microchemistry have been used for age determination, stock identification, life history and environmental tracing. Using X-ray diffraction （XRD） and Fourier transform infrared （FTIR） spectroscopy, we have determined the mineral types and crystalline characteristics of three pairs of otoliths from naked carp Gymnocypris przewalskii, the predominant fish in Lake Qinghai. The results indicate that the mineral of both lapillus and sagitta of the naked carp is aragonite, and that of asteriscus is vaterite. The aragonite of lapillus has prefect crystallization. Given the shape of lapillus and the sensitivity of its aragonite to water chemistry, lapillus was used to analyze temporal Sr/Ca ratios along the maximal growth axis by an electron probe microanalyzer （EPMA）. Consistent variations of Sr/Ca ratios with a range of 1.0x10-3-5.0~10-3 on the long and short radii indicate that Sr/Ca ratios of lapillus potentially respond to the chemical compositions of the host waters during the period of the naked carp＇s growth and migration. Discontinuous （dark） zones of lapillus were formed during fall and winter when the naked carp grows slowly in Lake Qinghai, resulting in similar low Sr/Ca ratios to lake water, whereas incremental zones with higher St/Ca ratios respond to its migratory river waters during spring and summer. Various Sr/Ca ratios of incremental zones suggest that the migratory pattern of the naked carp may be much more flexible, rather than in a single river. Therefore, high-resolution otolith microchemistry of the naked carp can be used to trace its migratory behavior, which is of significance for determining its migratory pattern and life history of this precious species inhabiting the Tibetan Plateau.

关键词： Lake Qinghai naked carp otolith migration aragonite Sr/Ca ratio environmental tracer

Prediction of Velocity and Deformation Fields During Multipass Plate Hot Rolling by Novel Mixed Analytical-Numerical Method

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Journal of Iron and Steel Research International 2011年第7期18卷 20-27页

作者： ZHANG jin-ling CUI Zhen-shan National Die and Mold CAD Engineering Research Center Shanghai Jiao Tong University Shanghai 200030 China

An integrated mathematical model is proposed to predict the velocity field and strain distribution during multi-pass plate hot rolling. This model is a part of the mixed analytical-numerical method （ANM） aiming at predic- tion of deformation variables, temperature and microstructure evolution for plate hot rolling. First a velocity field with undetermined coefficients is developed according to the principle of volume constancy and characteristics of metal flow during rolling, and then it is solved by minimizing the total energy consumption rate. Meanwhile a thermal model coupling with the plastic deformation is exploited through series function solution to determine temperature distribution and calculate the flow stress. After that, strain rate field is calculated through geometric equations and strain field is derived by means of difference method. This model is employed in simulation of an industrial seven pass plate hot rolling process. The velocity field result and strain field result are in good agreement with that from FEM simulation. Furthermore, the rolling force and temperature agree well with the measured ones. The compari- sons verify the validity of the presented method. The calculation of temperature, strain and strain rate are helpful in predicting microstructure. Above all, the greatest advantage of the presented method is the high efficiency, it only takes 12 s to simulate a seven-pass schedule, so it is more efficient than other numerical methods such as FEM.

关键词： multi-pass plate rolling analytical-numerical method (ANM) velocity field strain field strain rate

The finite-time ruin probability in the presence of Sarmanov dependent financial and insurance risks

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Applied Mathematics(A Journal of Chinese Universities) 2014年第2期29卷 194-204页

作者： YANG Yang LIN jin-guan TAN Zhong-quan School of Mathematics and Statistics Nanjing Audit University School of Economics and Management Southeast University Department of Mathematics Southeast University College of Mathematics Physics and Information Engineering Jiaxing University

Consider a discrete-time insurance risk model. Within period i, i≥ 1, Xi and Yi denote the net insurance loss and the stochastic discount factor of an insurer, respectively. Assume that {（Xi, Yi）, i≥1） form a sequence of independent and identically distributed random vectors following a common bivariate Sarmanov distribution. In the presence of heavy-tailed net insurance losses, an asymptotic formula is derived for the finite-time ruin probability.

关键词： Asymptotics long-tailed and dominatedly-varying-tailed distribution financial and insurancerisks finite-time ruin probability bivariate Sarmanov distribution.