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Mean-field potential calculations of high-pressure equation of state for BeO

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Chinese Physics B 2008年第4期17卷 1341-1348页

作者：张其黎张平宋海峰刘海风 institute of applied Physics and Computational Mathematics

A systematic study of the Hugoniot equation of state, phase transition, and the other thermodynamic properties including the Hugoniot temperature, the electronic and ionic heat capacities, and the Gruneisen parameter for shockcompressed BeO, has been carried out by calculating the total free energy. The method of calculations combines first-principles treatment for 0 K and finite-T electronic contribution and the mean-field-potential approach for the vibrational contribution of the lattice ion to the total energy. Our calculated Hugoniot is in good agreement with the experimental data.

关键词： Hugoniot mean-field-potential,first-principles

A Survey and Experimental Review on data Distribution Strategies for Parallel Spatial Clustering Algorithms

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Journal of Computer Science & Technology 2024年第3期39卷 610-636页

作者： Jagat Sesh Challa Navneet Goyal Amogh Sharma Nikhil Sreekumar Sundar Balasubramaniam Poonam Goyal Advanced data analytics and Parallel Technologies Laboratory Birla Institute of Technology and Science Pilani 333031India Uber New York 11101U.S.A. Computer Science and Engineering Department University of MinnesotaMinneapolis 55455U.S.A.

The advent of Big data has led to the rapid growth in the usage of parallel clustering algorithms that work over distributed computing frameworks such as MPI,MapReduce,and *** important step for any parallel clustering algorithm is the distribution of data amongst the cluster *** step governs the methodology and performance of the entire *** typically use random,or a spatial/geometric distribution strategy like kd-tree based partitioning and grid-based partitioning,as per the requirements of the ***,these strategies are generic and are not tailor-made for any specific parallel clustering *** this paper,we give a very comprehensive literature survey of MPI-based parallel clustering algorithms with special reference to the specific data distribution strategies they *** also propose three new data distribution strategies namely Parameterized Dimensional Split for parallel density-based clustering algorithms like DBSCAN and OPTICS,Cell-Based Dimensional Split for dGridSLINK,which is a grid-based hierarchical clustering algorithm that exhibits efficiency for disjoint spatial distribution,and Projection-Based Split,which is a generic distribution *** of these preserve spatial locality,achieve disjoint partitioning,and ensure good data load *** experimental analysis shows the benefits of using the proposed data distribution strategies for algorithms they are designed for,based on which we give appropriate recommendations for their usage.

关键词： parallel data mining data distribution parallel clustering spatial locality preservation

Mechanical, electronic, and thermodynamic properties of zirconium carbide from first-principles calculations

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Chinese Physics B 2015年第11期24卷 352-357页

作者：杨晓勇鲁勇郑法伟张平 institute of applied Physics and Computational Mathematics

Mechanical, electronic, and thermodynamic properties of zirconium carbide have been systematically studied using the ab initio calculations. The calculated equilibrium lattice parameter, bulk modulus, and elastic constants are all well consistent with the experimental data. The electronic band structure indicates that the mixture of C 2p and Zr 4d and 4p orbitals around the Fermi level makes a large covalent contribution to the chemical bonds between the C and Zr atoms. The Bader charge analysis suggests that there are about 1.71 electrons transferred from each Zr atom to its nearest C atom. Therefore, the Zr-C bond displays a mixed ionic/covalent character. The calculated phonon dispersions of ZrC are stable, coinciding with the experimental measurement. A drastic expansion in the volume of ZrC is seen with increasing temperature, while the bulk modulus decreases linearly. Based on the calculated phonon dispersion curves and within the quasi-harmonic approximation, the temperature dependence of the heat capacities is obtained, which gives a good description compared with the available experimental data.

关键词： first-principles calculations mechanical properties electronic properties thermodynamic properties

Measurements of Laminar Burning Velocities of Alternative Fuels:Application in Transport and Aerospace

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Journal of Thermal Science 2023年第2期32卷 503-512页

作者： RICHTER Sandra BRAUN-UNKHOFF Marina NAUMANN Clemens German Aerospace Center(DLR) Institute of Combustion TechnologyDepartment of Chemical Kinetics and AnalyticsStuttgart 70569Germany

The laminar burning velocity belongs to the fundamental combustion properties of fuels being a measure for their heat release,flame length,as well as reactivity and combustion stability,and thus,may impact the design of burners and combustion ***,these experimental data are needed for the validation and optimization within the construction and development of detailed chemical kinetic reaction *** this study,an overview of the different applications of fuel characterization regarding the specific area of interest(road transport,aviation,and aerospace)will be *** on the application,effects of different molecular characteristics on the laminar burning velocity are evaluated:the presence of oxygen atoms and the grade of branching in a specific fuel molecule as well as the difference in the type of a chemical bond,here,single and double *** of alternative fuels being discussed in the present study are:(Ⅰ)oxymethylene ether(OMEn)in the field of road transport;(Ⅱ)a paraffinic Alcohol-to-Jet fuel as sustainable aviation fuel;and(Ⅲ)mixtures of ethane or ethene with nitrous oxide as green propellants for rocket propulsion applications.

关键词： laminar burning velocity alternative sustainable fuels road transport aviation fuels green propellants

Systems biology of resilience and optimal health:integrating Chinese and Western medicine perspectives

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World Journal of Traditional Chinese Medicine 2017年第1期3卷 38-49页

作者： Herman van Wietmarschen Yan Schroёn Victor Kallen Marvin Steijaert Albert A.de Graaf Ben van Ommen Jan van der Greef TNO The Netherlands Organization for applied Scientific Research Sino Dutch centre for Preventive and personalized Medicine Louis Bolk institute Open analytics

Western science has been strong in measuring details of biological systems such as gene expression levels and metabolite concentrations, and has generally followed a bottom up approach with regard to explaining biological phenomena. Chinese medicine in contrast has evolved as a top down approach in which body and mind is seen as a whole, a phenomenological approach based on the organization and dynamics of symptom patterns. Western and Chinese perspectives are developing towards a ‘middle out' approach. Chinese medicine diagnosis, we will argue, allows bridging the gap between biologists and psychologists and offers new opportunities for the development of health monitoring tools and health promotion *** this paper, health, resilience and stress concepts are explored from an integrated systems biology perspective. This is followed by a discussion about measuring aspects of health and resilience. Then the issue of how to integrate different types of data is discussed. Semi-quantitative modeling appears to be very suitable and looks promising for building integrated health models. The challenge for the future lies in applying those models in developing personalized health monitoring and advice systems that will tempt people to lead more healthy lives.

关键词： Health Wellness Resilience Systems biology Chinese diagnosis

Effect of Electron Correlation and Breit Interaction on Energies, Oscillator Strengths, and Transition Rates for Low-Lying States of Helium

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Chinese Physics Letters 2021年第11期38卷 23-29页

作者： Qing Liu Jiguang Li Jianguo Wang Yizhi Qu School of Optoelectronics University of Chinese Academy of SciencesBeijing 100049China data Center for High Energy Density Physics Institute of Applied Physics and Computational MathematicsBeijing 100088China

The transition energies, E1 transitional oscillator strengths of the spin-allowed as well as the spin-forbidden and the corresponding transition rates, and complete M1, E2, M2 forbidden transition rates for 1s^(2), 1s2s, and 1s2p states of He I, are investigated using the multi-configuration Dirac–Hartree–Fock method. In the subsequent relativistic configuration interaction computations, the Breit interaction and the QED effect are considered as perturbation, separately. Our transition energies, oscillator strengths, and transition rates are in good agreement with the experimental and other theoretical results. As a result, the QED effect is not important for helium atoms, however, the effect of the Breit interaction plays a significant role in the transition energies, the oscillator strengths and transition rates.

关键词： QED Dirac Oscillator Strengths and Transition Rates for Low-Lying States of Helium Effect of Electron Correlation and Breit Interaction on Energies

A Nonlocal Stokes Systemwith Volume Constraints

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Numerical Mathematics(Theory,Methods and Applications) 2022年第4期15卷 903-937页

作者： Qiang Du Zuoqiang Shi Department of applied Physics and applied Mathematics and Data Science InstituteColumbia UniversityNew YorkNY 10027USA Yau Mathematical Sciences Center Tsinghua UniversityBeijing 100084China Yanqi Lake Beijing institute of Mathematical Sciences and Applications Beijing 101408China

In this paper,we introduce a nonlocal model for linear steady Stokes system with physical no-slip boundary *** use the idea of volume constraint to enforce the no-slip boundary condition and prove that the nonlocal model is *** also show that and the solution of the nonlocal system converges to the solution of the original Stokes system as the nonlocality vanishes.

关键词： Nonlocal Stokes system nonlocal operators smoothed particle hydrodynamics incompressible flows well-posedness local limit

A simulation package—SASAL for X-ray and EUV spectroscopy of astrophysical and laboratory plasmas

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Research in Astronomy and Astrophysics 2014年第10期14卷 1351-1366页

作者： Gui-Yun Liang Fang Li Fei-Lu Wang Yong Wu Jia-Yong Zhong Gang Zhao Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of Sciences data Center for High Energy Density Physics Institute of Applied Physics and Computational Mathematics

For the laboratory astrophysics community, those spectroscopic modeling codes extensively used in astronomy, e.g. Chianti, AtomDB, Cloudy and Xstar, cannot be directly applied to analyzing laboratory measurements due to their discrepancies from astrophysical cases. For example, plasma from an electron beam ion trap has an electron energy distribution that follows a Gaussian profile, instead of a Maxwellian one. The laboratory miniature for a compact object produced by a laser-driven implo- sion shows a departure from equilibrium, that often occurs in celestial objects, so we setup a spectral analysis system for astrophysical and laboratory （SASAL） plasmas to act as a bridge between them, which benefits the laboratory astrophysical community.

关键词： atomic data -- line formation -- plasmas -- X-rays general

Probing dynamic interference in high-order harmonic generation from long-range molecular ion:Bohmian trajectory investigation

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Chinese Physics B 2014年第5期23卷 233-237页

作者：王俊王兵兵郭福明李苏宇丁大军陈基根曾思良杨玉军 institute of Atomic and Molecular Physics Jilin University Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of Sciences Department of Physics and Materials Engineering Taizhou University Science and Technology Computation Physics Laboratory Institute of Applied Physics and Computational Mathematics data Center for High Energy Density Physics Institute of Applied Physics and Computational Mathematics

Using Bohmlan trajectory （151） method, we investigate the dynamic interference in nlgn-orcter narmonlc generauon from diatomic molecular ions. It is demonstrated that the main characteristics of the molecular harmonic spectrum can be well reproduced by only two BTs which are located at the two ions. This haiapens because these two localized trajectories can receive and store the whole collision information coming from all of the other re-collision trajectories. Therefore, the amplitudes and frequencies of these two trajectories represent the intensity and frequency distribution of the harmonic generation. Moreover, the interference between these two trajectories shows a dip in the harmonic spectrum, which reveals the molecular structure information.

关键词： Bohmian trajectory molecular high-order harmonic generation dynamic interference