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Performance of an elliptical crystal spectrometer for SGⅡX-ray opacity experiments

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High Power Laser Science and Engineering 2018年第1期6卷 13-19页

作者： Ruirong Wang Honghai An Zhiyong Xie Wei Wang Shanghai institute of Laser Plasma Shanghai 201800 China

A new crystal spectrometer for application in X-ray opacity experiments is proposed. The conditions necessary to yield broad spectral coverage with a resolution >500, strong rejection of hard X-ray backgrounds and negligible source broadening for extended sources are formulated. In addition, the design, response modeling and reporting of an elliptical crystal spectrometer in conjunction with a linear detector are presented. The measured results demonstrate the performance of the new crystal spectrometer with a broad energy coverage range, high spectral resolution, and high luminosity(good collection efficiency). This spectrometer can be used in combination with point-projection backlighting techniques as utilized in X-ray opacity experiments. Specifically, the X-ray source, transmission and self-emission spectra of the sample can be measured simultaneously in a single shot, which can reduce the experimental uncertainties from shot-to-shot fluctuations. The new crystal spectrometer has been used in the X-ray opacity experiment to precisely measure the aluminum K-absorption edge shift in the energy range around 1.560 keV in strongly compressed matter. It is demonstrated that the spectrometer can be used to realize measurements of new and unpredictable physical interactions of interest, as well as basic and applied high-energy-density science.

关键词： high energy density physics inertial confinement fusion ultra-intense ultra-short pulse laser interaction with matters

An　alternating　direction　implicit　（ADI）　numerical　model　for　two－dimensional　hydrodynamic　equations

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Acta Oceanologica Sinica 1995年第1期14卷 1-13页

作者： Pan Haiand Fang Guohong(institute of Dceanology, Academia Sinica, Qingdao 266071, China)(Present address: institute of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ 08903-0231, USA) institute of Oceanology Academia Sinica Qingdao 266071 China

A two-dimensional computational model is develope for the calulation of tides, storm surges and otherlong-period waves in coastal and shelf waters. The Partial differental equations are approximated by two sets of difference equations on a space-staggered grid system. Both sets are explicit with one set for water level and x-component velocity, and another for water level and y-component velocity. These two sets are used successively for stepby-step solution in time. An analytical investigation on the linearized sets of the difference equations indicates that thecomputational scheme is unconditionally stable. The model is of second order accuracy both in space and in time andconserves mass and momentum. Simulations of surface elevation caused by periodic forcing in one-opening rectangularbasin with flat topography and by steady wind stress in the basin with flat or slope topography show that the computed results are in excellent agreement with the corresponding analytic solutions. The steady-tate wind-induced setupin a ofed basin with discontinuous topography computed with the present model are also in excellent agreement withthe results from Leendertse's model. Finally, the model is applied to hindcast a storm surge in the South China Seaand reproduces the surge elevation satisfactorily.

关键词： ADI numerical model two-dimensional hydrodynamic equations

Optimizing the Computation of Many-Pair Density Matrix in VDPC

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Journal of applied mathematics and Physics 2022年第7期10卷 2303-2312页

作者： Jin Li Wanli Ma Department of Physics University of Shanghai for Science and Technology Shanghai China Department of mathematics University of Shanghai for Science and Technology Shanghai China

Recently an algorithm that acts the variational principle directly to a coherent-pair condensate (VDPC) has been proposed. This algorithm can avoid time-consuming projection while maintaining particle number conservation. Quickly computation of many-pair density matrix (MPDM) is one of the keys to improve the computational efficiency of VDPC algorithm. In this work, we propose a scheme that limits the energy range of block particles to the vicinity of the Fermi surface, which reduces the time complexity of computing the MPDM without losing physical details. The results show that by appropriately limiting the energy range, we can greatly reduce the number of matrix elements that need to be computed, and reducing the time required for the computation.

关键词： Nuclear Structure Mean-Field Theory BCS Density Matrix VDPC

A novel structural modeling and analysis of VLSI interconnect with an RLC tree network system using a BG/SEBD approach

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Science China(Information Sciences) 2011年第9期54卷 1968-1985页

作者： CHANG RueyFong KAO WenShiow TSENG KuoHsiung HUANG ShihYing Department of Electrical Engineering National Taipei University of Technology Department of Environmental Resources Management Transworld Institute of Technology

A practical and effective novel graphical structural modeling and analysis approach is *** approach is used for solving the state interactions modeling problem caused by the model approximations in VLSI interconnect for RLC tree network *** bond graph (BG) energy model with a simulink energy-based block diagram (SEBD) algorithm is *** dynamic behaviors of an example of VLSI interconnect with a 20th-order RLC tree are *** of sequent structuring and the delineation of dynamic interactions can be provided for users applying the BG/SEBD algorithms in the development of structural *** is shown that the new BG/SEBD structural modeling approach requires neither mathematical higher-order reduction nor physically based model ***,useful information can be extracted from the BG/SEBD representation of physical RLC tree network *** time-domain and frequency-domain simulation results are applied to analyze the dynamic response of energy-storing elements using BG/SEBD algorithm combined with Matlab/Simulink ***,a causal analysis of the system zeros plot from the shortest causal path method is proposed,to predict the dynamic response of energy-storing elements and the system performance for design and verification *** dynamic response outputs from different node points were revealed,and the obtained physical information is significant which suggests feasible directions for design (re-design) improvement toward better overall system performance.

关键词： higher-order RLC tree interconnect network (RLC-TIN) bond graph (BG) structural modeling time-domain and frequency-domain analysis causality analysis

SIMULATION OF THE SEISMIC TECTONIC STRESS FIELD IN NORTH CHINA

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Science China Chemistry 1982年第9期25卷 1000-1010页

作者：王仁黄杰藩孙荀英安欧郭世凤宋惠珍潘善德黄庆华沈淑敏杨建华 institute of Geology State Seismological Buream institute of Geomechanics Ministry of Geology Hebei Province Peking University Beijing Seismo-geological Team Geological Team No. 562 Chinese Academy of Geological Sciences State Seismological Bureau

The paper reviews several methods of simulation used in this country to recover currenttectonic stress field related to earthquake occurrence in North China. The aim is to evaluatethe degree of seismic risk around Beijing area. The methods used are computational ormathematical simulation by the finite element method and experimental or physical simulationby the photoelastic method and the grid method. The results obtained by these methods arebriefly described. Most simulations indicate that Beijing is not a region of seismic risk.

关键词： SIMULATION OF THE SEISMIC TECTONIC STRESS FIELD IN NORTH CHINA

龙马溪—五峰组富有机质页岩三维岩石物理模板分析及“甜点”预测

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地球物理学报 2021年第8期64卷 2900-2915页

作者：檀文慧巴晶符力耘 Jose M.Carcione 周欣河海大学地球科学与工程学院地球探测研究所南京211100 中国石化石油物探技术研究院南京211103 中国石油大学(华东) 地球科学与技术学院山东青岛266580 National institute of Oceanography and applied Geophysics(OGS) TriesteItaly

为识别四川盆地丁山区龙马溪—五峰组目的层富含页岩气的“甜点区”,本文对页岩的有机碳含量、脆性、孔隙度及微裂隙等核心指标进行分析研究.对页岩展开岩石物性特征和岩石物理分析,结果显示“甜点区”具有TOC含量高、高孔隙度、低密度... 详细信息

为识别四川盆地丁山区龙马溪—五峰组目的层富含页岩气的“甜点区”,本文对页岩的有机碳含量、脆性、孔隙度及微裂隙等核心指标进行分析研究.对页岩展开岩石物性特征和岩石物理分析,结果显示“甜点区”具有TOC含量高、高孔隙度、低密度、脆性高(石英含量高)的特点,此外储层的拉梅常数和密度的乘积λρ分布范围是18~30 GPa·g·cm^(-3),泊松比υ范围是0.18~0.22,剪切模量μ范围是13~18 GPa.根据储层的岩石物理特征,同时考虑孔隙度、裂隙纵横比和矿物组分对优质页岩敏感弹性参数的影响,采用等效嵌入体应力平均(EIAS)理论模型构建适合页岩气储层的三维岩石物理模板,进而预测储层的孔隙度、裂隙纵横比和石英矿物含量.基于测井数据,对构建的三维岩石物理模板进行校正,将校正后的模板应用到研究工区,选取过三口井的二维测线和三维区块,进行孔隙度、裂隙纵横比和石英矿物含量的定量预测.对比实际资料分析得出的优质页岩储层孔隙度预测范围与测井结果吻合较好,过三口井的目的层产气情况与预测结果一致性良好,目的层页岩具有高孔隙度、低裂隙纵横比和高石英含量的特征,可有效地指示优质页岩储层分布.

关键词：页岩气有机碳含量脆性孔隙度 “甜点”预测岩石物理模板

computational design of catalysts for ammonia synthesis

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Nano Research Energy 2023年第3期2卷 56-65页

作者： Yining Zhang Sha Li Wei Zheng Xi Wang Chemistry and Chemical Engineering Guangdong Laboratory Shantou 515021China institute of Molecular Plus Tianjin UniversityTianjin 300072China Department of Physics School of Physical Science and EngineeringBeijing Jiaotong UniversityBeijing 100044China

Ammonia plays a crucial role in agriculture and chemical engineering,and acts as a promising carbon-free transportation *** design is deemed as a key to solve the restriction of energy-intensive Haber-Bosch process of ammonia *** the development of computational modeling,computation-aided catalyst design serves as one important driving force for material innovation,saving a lot of experimental efforts based on trial and *** modeling not only provides fundamental mechanistic insights into the reaction with great details regarding adsorbate geometries,electronic structures,and elementary-step energies,but also expedites the material discovery with descriptor-based catalyst design,core of which is the establishment of thermo/kinetic scaling *** this review,we present firstly the mechanistic understanding of ammonia synthesis and transition state scaling relations developed on pure transition-metal *** then summarize catalysts design strategies guided by alloy,size,and magnetic effects with the goal of breaking the limitations set by scaling relations to achieve better catalytic ***,future opportunities and challenges associated with computation design of optimal catalysts for ammonia synthesis are outlined.

关键词： catalyst design ammonia synthesis computational modeling scaling relations

Construction of ground-state preserving sparse lattice models for predictive materials simulations

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npj computational Materials 2017年第1期3卷 203-211页

作者： Wenxuan Huang Alexander Urban Ziqin Rong Zhiwei Ding Chuan Luo Gerbrand Ceder Department of Material Science and Engineering Massachusetts Institute of TechnologyCambridgeMAUSA Department of Materials Science and Engineering UC BerkeleyBerkeleyCAUSA institute of Computing Technology Chinese Academy of SciencesBeijing 100190China Materials Science Division Lawrence Berkeley National LaboratoryBerkeleyCAUSA

First-principles based cluster expansion models are the dominant approach in ab initio thermodynamics of crystalline mixtures enabling the prediction of phase diagrams and novel ground ***,despite recent advances,the construction of accurate models still requires a careful and time-consuming manual parameter tuning process for ground-state preservation,since this property is not guaranteed by *** this paper,we present a systematic and mathematically sound method to obtain cluster expansion models that are guaranteed to preserve the ground states of their reference *** method builds on the recently introduced compressive sensing paradigm for cluster expansion and employs quadratic programming to impose constraints on the model *** robustness of our methodology is illustrated for two lithium transition metal oxides with relevance for Li-ion battery cathodes,i.e.,Li_(2x)Fe_(2(1−x))O_(2) and Li_(2x)Ti_(2(1−x))O_(2),for which the construction of cluster expansion models with compressive sensing alone has proven to be *** demonstrate that our method not only guarantees ground-state preservation on the set of reference structures used for the model construction,but also show that out-of-sample ground-state preservation up to relatively large supercell size is achievable through a rapidly converging iterative *** method provides a general tool for building robust,compressed and constrained physical models with predictive power.

关键词： cluster preserving thermodynamics

Integrated data analysis on the electron temperature profile of HL-2A with the Bayesian probability inference method

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Plasma Science and Technology 2022年第5期 261-276页

作者：潘文安王天博王志斌杨勇濠吴豪 Geert VERDOOLAEGE 杨曾辰刘春华郭文平李兵利刘自结吴文斌许敏 Sino-French institute of Nuclear Engineering and Technology Sun Yat-sen University Ghent University University of Science and Technology of China Southwestern institute of Physics

Data analysis on tokamak plasmas is mainly based on various diagnostic systems, which are usually modularized and independent of each other. This leads to a large amount of data not being fully and effectively exploited so that it is not conducive to revealing the deep physical *** this work, Bayesian probability inference with machine learning methods have been applied to the electron cyclotron emission and Thomson scattering diagnostic systems on HL-2A/2M, and the effects of integrated data analysis(IDA) on the electron temperature of HL-2A with Bayesian probability inference are demonstrated. A program is developed to infer the whole electron temperature profile with a confidence interval, and the program can be applied in online *** IDA results show that the full profile of the electron temperature can be obtained and the diagnostic information is more comprehensive and abundant with IDA. The inference models for electron temperature analysis are established and the developed programs will serve as an experimental data analysis tool for HL-2A/2M in the near future.

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