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Graphic Sequences with a Realization Containing Intersecting Cliques

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Acta Mathematica Sinica,English Series 2012年第2期28卷 405-416页

作者： Jian Hua YIN Yan Fang DENG department of Mathematics College of Information Science and Technology Hainan University

Let r ≥1, k ≥ 2 and Fm1,… k;r denote the most general definition of a friendship graph,

关键词： Degree sequence potentially P-graphic sequence

Early Paleogene Arctic terrestrial ecosystems affected by the change of polar hydrology under global warming:Implications for modern climate change at high latitudes

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science China Earth sciences 2010年第7期53卷 933-944页

作者： Gaytha A. LANGLOIS department of science and Technology College of Arts and Sciences Bryant University

Our understanding of both the role and impact of Arctic environmental changes under the current global warming climate is rather limited despite efforts of improved monitoring and wider assessment through remote sensing technology. Changes of Arctic ecosystems under early Paleogene warming climate provide an analogue to evaluate long-term responses of Arctic environmental alteration to global warming. This study reviews Arctic terrestrial ecosystems and their transformation under marked change of hydrological conditions during the warmest period in early Cenozoic, the Paleocene and Eocene. We describe a new approach to quantitatively reconstruct high latitudinal paleohydrology using compound-specific hydrogen isotope analysis which applies empirically derived genus-specific hydrogen isotope fractionations to in situ biomolecules from fossil plants. We propose a moisture recycling model at the Arctic to explain the reconstructed hydrogen isotope signals of ancient high latitude precipitation during early Paleogene, which bears implications to the likely change of modern Arctic ecosystems under the projected accelerated global warming.

关键词： Paleogene climate Arctic ecosystems global warming global hydrology vegetation change

QUASI-NEUTRAL LIMIT OF THE BIPOLAR NAVIER-STOKES-POISSON SYSTEM

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Acta Mathematica Scientia 2011年第4期31卷 1272-1280页

作者：杨秀绘 department of Mathematics College of Science Nanjing University of Aeronautics and Astronautics

This paper is concerned with the quasi-neutral limit of the bipolar NavierStokes-Poisson system. It is rigorously proved, by introducing the new modulated energy functional and using the refined energy analysis, that the strong solutions of the bipolar Navier-Stokes-Poisson system converge to the strong solution of the compressible NavierStokes equations as the Debye length goes to zero. Moreover, if we let the viscous coefficients and the Debye length go to zero simultaneously, then we obtain the convergence of the strong solutions of bipolar Navier-Stokes-Poisson system to the strong solution of the compressible Euler equations.

关键词： bipolar Navier-Stokes-Poisson system compressible Navier-Stokes equations compressible Euler equations modulated energy functional

Generation of valley pump currents in silicene

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Chinese Physics B 2019年第1期28卷 570-574页

作者： John Tombe Jada Marcellino Mei-Juan Wang Sa-Ke Wang department of Physics Southeast University college of science Jinling Institute of Technology

We propose a workable scheme for generating a bulk valley pump current in a silicene-based device which consists of two pumping regions characterized by time-dependent strain and staggered potentials, respectively. In a one-dimension model, we show that a pure valley current can be generated, in which the two valley currents have the same magnitude but flow in opposite directions. Besides, the pumped valley current is quantized and maximized when the Fermi energy of the system locates in the bandgap opened by the two pumping potentials. Furthermore, the valley current can be finely controlled by tuning the device parameters. Our results are useful for the development of valleytronic devices based on two-dimensional materials.

关键词： valley currents charge pump quantization silicene

Quantum Discord-Breaking Channels

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Chinese Physics Letters 2013年第9期30卷 14-17页

作者： YAO Chun-Mei HE Zhi CHEN Zhi-Hua NIE Jian-Jun college of Physics and Electronics Hunan University of Arts and ScienceChangde 415000 department of science Zhijiang CollegeZhejiang University of TechnologyHangzhou 310024

Through comparisons with an entanglement breaking(EB)channel,we characterize the local quantum channels that destroy quantum correlations,especially for quantum discord,and give a detailed description of a discord-breaking(DB)*** prove that the quantum discord can be broken if and only if the local quantum channel is a commutativity-creating(CoC)*** we show which kind of channels is a CoC channel,and address the relation between EB and DB *** we apply our results to three typical noise channels.

关键词： quantum breaking apply

A Characterization for a Sequence to be Potentially K_(r+1) — e-graphic

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Acta Mathematicae Applicatae Sinica 2013年第4期29卷 787-792页

作者： Jian-hua YIN Ye WANG department of Mathematics College of Information Science and TechnologyHainan University

Let n 〉 r, let lr --- （dl,d2,-,dn） be a non-increasing sequence of nonnegative integers and let Kr＋l - e be the graph obtained from Kr＋l by deleting one edge. If zr has a realization G containing Kr＋l - e as a subgraph, then r is said to be potentially Kr＋l - e-graphic. In this paper, we give a characterization for a sequence π to be potentially Kr＋l - e-graphic.

关键词： graph degree sequence potentially Kr+1 - e-graphic sequence

Adaptive diagonal loaded minimum variance beamforming applied to medical ultrasound imaging

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Journal of Central South University 2015年第5期22卷 1826-1832页

作者：刘昊霖张志宏刘东权 college of Computer science Sichuan University department of Computer science and Technology Changsha University Saset Healthcare Inc

In order to enhance the robustness and contrast in the minimum variance(MV) beamformer, adaptive diagonal loading method was proposed. The conventional diagonal loading technique has already been used in the MV beamformer, but has the drawback that its level is specified by predefined parameter and without consideration of input-data. To alleviate this problem, the level of diagonal loading was computed appropriately and automatically from the given data by shrinkage method in the proposed adaptive diagonal loaded beamformer. The performance of the proposed beamformer was tested on the simulated point target and cyst phantom was obtained using Field II. In the point target simulation, it is shown that the proposed method has higher lateral resolution than the conventional delay-and-sum beamformer and could be more robust in estimating the amplitude peak than the MV beamformer when acoustic velocity error exists. In the cyst phantom simulation, the proposed beamformer has shown that it achieves an improvement in contrast ratio and without distorting the edges of cyst.

关键词： medical ultrasound imaging minimum variance beamforming diagonal loading delay-and-sum beamforming contrast robustness

Low Timing Jitter and Tunable Dual-Wavelength Picosecond Pulse Generation from a Fabry-Pérot Laser Diode with External Injection

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Chinese Physics Letters 2007年第6期24卷 1573-1576页

作者：杨毅彪王云才张明江梁伟 department of Physics College of Science Taiyuan University of Technology Taiyuan 030024 college of Materials science and Engineering Taiyuan University of Technology Taiyuan 030024

A novel scheme to generate tunable dual-wavelength optical pulses with low timing jitter at arbitrary repetition rates is proposed and demonstrated experimentally. The pulses are generated from a gain-switched Fabry-Pérot laser diode with two external cw beams for injection seeding simultaneously. The cw light is generated by two independent distributed feedback laser diodes, and their wavelengths can be tuned independently by two temperature controllers. The dual-wavelength pulses with the pulse width of 57 ps, the timing jitter of 340 fs, are obtained. The sidemode-suppression ratio of the output pulses is better than 23dB over a 10-nm wavelength tuning range.

关键词： Dual-Wavelength Generation Fabry--Pérot

LA-ICP-MS U-Pb Geochronology of Detrital Zircons in Eastern Liaoning Province： An Early Paleozoic Formation Associated with the Gondwana Supercontinent Event

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Acta Geologica Sinica(English Edition) 2018年第3期92卷 1262-1264页

作者： DONG Xiaojie LIU Zhenghong XU Zhongyuan LIU Yongjun LIU Jiexun college of Earth science Jilin University Changchun 130061 Jilin China Liaoning Research Institute of geology and Mineral Resources Shenyang 110032 Liaoning China

Objective The Liao-Ji orogenic belt is a famous Paleoproterozoic orogenic belt in the East Block of the North China Craton(NCC),which extend in NE-SW *** geological mass in the Paleoproterozoic Liao-Ji belt is mainly ... 详细信息

关键词： LA-ICP-MS U-Pb Geochronology of Detrital Zircons Eastern Liaoning Province the Gondwana Supercontinent Event