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Nuclear level density from relativistic density functional theory and combinatorial method

PHYSICS LETTERS B 2024年 849卷

作者： Jiang, X. F. Wu, X. H. Zhao, P. W. Meng, J. Peking Univ Sch Phys State Key Lab Nucl Phys & Technol Beijing 100871 Peoples R China Fuzhou Univ Dept Phys Fuzhou 350108 Fujian Peoples R China Kyoto Univ Yukawa Inst Theoret Phys Kyoto 6068502 Japan

Nuclear level density is calculated with the combinatorial method based on the relativistic density functional theory including pairing correlations. The Strutinsky method is adopted to smooth the total state density in order to refine the prediction at low excitation energy. The impacts of pairing correlations and moments of inertia on the nuclear level density are discussed in detail. Taking Cd-112 as an example, it is demonstrated that the nuclear level density based on the relativistic density functional PC-PK1 can reproduce the experimental data at the same level as or even better than the previous approaches.

关键词： Nuclear level density Relativistic density functional theory combinatorial method Strutinsky method

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combinatorial method for Aggregation of Incomplete Group Judgments 1

Combinatorial Method for Aggregation of Incomplete Group Jud...

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1st IEEE International Conference on System Analysis & Intelligent Computing (SAIC)

作者： Tsyganok, Vitalii Kadenko, Sergii Andriichuk, Oleh Roik, Pavlo Natl Acad Sci Ukraine Inst Informat Recording Kiev Ukraine

ISBN: (纸本)9781538671962

A method for aggregation of expert estimates in small groups is proposed. The method is based on combinatorial approach to decomposition of pair-wise comparison matrices and to processing of expert data. It also uses the basic principles of AHP/ANP approaches, such as building of criteria hierarchy to decompose and describe the problem, and evaluation of objects by means of pair-wise comparisons. It allows to define priorities based on group incomplete pair-wise comparisons and to organize feedback with experts to achieve sufficient agreement of their estimates. Double entropy inter-rater index is suggested for usage as agreement measure. Every expert is given an opportunity to use the scale, in which the degree of detail most adequately reflects this expert's competence in the issue under consideration, for every single pair comparison. The method takes all aspects of individual expert competence into consideration. The method is meant for use in weakly-structured subject domains in the process of strategic planning.

关键词： group decision making incomplete pair-wise comparisons combinatorial method feedback with experts scales with different numbers of grades

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Advanced combinatorial method for solving complex fault trees

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ANNALS OF NUCLEAR ENERGY 2018年 120卷 666-681页

作者： Rivero Oliva, Jose de Jesus Salomon Llanes, Jesus Perdomo Ojeda, Manuel Torres Valle, Antonio Univ Fed Rio De Janeiro UFRJ Dept Engn Nucl Rio De Janeiro Brazil Univ La Habana UH Inst Super Tecnol & Ciencias Aplicadas Havana Cuba

combinatorial explosion is a common problem to both predominant methods for solving fault trees: Minimal Cut Set (MCS) approach and Binary Decision Diagram (BDD). High memory consumption impedes the complete solution of very complex fault trees. Only approximated non-conservative solutions are possible in these cases using truncation or other simplification techniques. The paper proposes a new method (CSolv+) for solving complex fault trees, without any possibility of combinatorial explosion. Each individual MCS is immediately discarded after its contribution to the basic events importance measures and the Top gate Upper Bound Probability (TUBP) has been accounted. An estimation of the Top gate Exact Probability (TEP) is also provided. Therefore, running in a computers cluster, CSolv+ will guarantee the complete solution of complex fault trees. It was successfully applied to 40 fault trees from the Aralia fault trees data base, performing the evaluation of the top gate probability, the 1.000 Significant MCSs (SMCS) and the Fussell-Vesely, RRW and RAW importance measures for all basic events. The high complexity fault tree nus9601 was solved with truncation probabilities from 10(-21) to 10(-27), just to limit the execution time. The solution corresponding to 10(-27), evaluated 3.530.592.796 MCSs in 3 h and 15 min. (C) 2018 Elsevier Ltd. All rights reserved.

关键词： Fault tree analysis combinatorial method Minimal cut set

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combinatorial method FOR CHARACTERIZING SINGULAR CONFIGURATIONS IN PARALLEL MECHANISMS

COMBINATORIAL METHOD FOR CHARACTERIZING SINGULAR CONFIGURATI...

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ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference

作者： Sheffer, Avshalom Shai, Offer Tel Aviv Univ Sch Mech Engn IL-69978 Ramat Aviv Israel

ISBN: (纸本)9780791857144

The paper presents a method for finding the different singular configurations of several types of parallel mechanisms/robots using the combinatorial method. The main topics of the combinatorial method being used are: equimomental line/screw, self -stresses, Dual Kennedy theorem and circle, and various types of 2D and 3D Assur Graphs such as: triad, tetrad and double triad. The paper introduces combinatorial characterization of 3/6 SP and compares it to singularity analysis of 3/6 SP using Grassmann Line Geometry and Grassmann-Cayley Algebra. Finally, the proposed method is applied for characterizing the singular configurations of more complex parallel mechanisms such as 3D tetrad and 3D double -triad.

关键词： combinatorial method Equimomental Line/Screw Dual Kennedy theorem and circle Grassmann Line Geometry and Grdssmann-Cayley Algebra Self-Stress Singularity 3/6 SP

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A combinatorial method based on simulated annealing to design a biplanar MRI gradient system

A combinatorial method based on simulated annealing to desig...

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IEEE Nuclear Science Symposium

作者： D. Grau-Ruiz H. Sanchez J. P. Rigla E. Diaz-Caballero J. M. Gonzalez G. Puchalt A. Aguilar A. Gonzalez-Montoro A. J. Gonzalez S. Sanchez J. M. Benlloch Instituto de Instrumentacion para Imagen Molecular (I3M) Centro Mixto CSIC - Universitat Politecnica de Valencia Tesoro Imaging S.L.

ISBN: (纸本)9781538622834

Gradient coils are a main part of a Magnetic Resonance Imaging (MRI) system. The aim of gradient coils in a MRI system is to encode spatially the Field of View (FoV). Different gradient coil design methods have been presented in the last years. Some factors such as linearity, inductance and resistance must be taken in account to obtain an optimized design for the gradient coils. A combinatorial method to design the MRI gradient coils is presented. The method developed uses very simple shapes to obtain the coil path patternand it allows finding the best coil design in a time less than 2 minutes. Path combination which generates the highest gradient field is chosen for the X/Y gradient coil, and also the most homogeneous magnetic field is considered to select the Z-gradient path combination. Efficiencies values of 9.3 and 19.4 mT/m/A are obtained for X/Y and Z gradient coil, respectively. The gradient system has been tested in a biplanar permanent magnet (PM) system. Experimental gradient coil evaluation shows the ability to generate a strong gradient field (0.56 and 0.75 T/m for X/Y and Z gradient coil, respectively). A preliminary 2D MRI image with 1mm accuracy is obtained.

关键词： gradient coil Magnetic resonance imaging unit simulated annealing Coils combinatorial method Magnetic Resonance Imaging Gradient C7orf49 gene Optimal design biplanar magnetic field

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Detailed Analysis of Temperature Dependences of Spherulite Morphology and Crystallite Orientation of Poly(vinylidene fluoride) via a combinatorial method

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JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS 2015年第4期53卷 253-261页

作者： Xu, Duigong Bin, Yuezhen Tashiro, Kohji Dalian Univ Technol Dept Polymer Sci & Engn Dalian 116024 Peoples R China Toyota Technol Inst Grad Sch Engn Nagoya Aichi 4688511 Japan China Acad Engn Phys Mianyang 621900 Peoples R China Dalian Univ Technol Sch Chem Engn State Key Lab Fine Chem Dalian 116024 Peoples R China

Temperature dependences of spherulite morphology and crystal orientation of poly(vinylidene fluoride) (PVDF) were systematically investigated via a combinatorial method. The method created a temperature gradient ranging from 130 to 200 degrees C. Results show that the preferential orientation of the crystallites changes with the crystallization temperature. The crystallization at 169 degrees C gives the most highly developed crystalline state of PVDF crystalline form II ( form), in which the spherulite size is maximal, and the crystallite sizes are also the longest, about 200 nm along the b axes. Besides, the a-axis is almost parallel to the film normal. It indicates that the crystallization rate is the highest in the b-axis direction. The perferential orientation at higher temperatures may be attributed to the confined 2D growth of the PVDF spherulites in the thin film, whereas the spherulites grow in the 3D mode at lower temperatures. The crystallization behavior revealed in the method is consistent with the results of melt isothermal crystallization experiments. (c) 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015, 53, 253-261

关键词： combinatorial method crystal structures crystallization orientation poly(vinylidene fluoride) spherulite structural characterization temperature dependence

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Modular combinatorial Development of Crystal-Glass Nano-Heterostructured Copper Alloys with Ultrahigh Strength and Large Deformability

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ADVANCED FUNCTIONAL MATERIALS 2025年第3期35卷

作者： Zhou, Hongbo Yuan, Fusen Huang, Yao Wang, Yutian Bo, Zhenxing Cao, Jingshan Xie, Weijie Zhang, Qinghua Liu, Yanhui Jiang, Minqiang Sun, Baoan Wang, Weihua Chinese Acad Sci Inst Phys Beijing 100190 Peoples R China Chinese Acad Sci Inst Mech Beijing 100190 Peoples R China Univ Chinese Acad Sci Ctr Mat Sci & Optoelect Engn Beijing 100049 Peoples R China Songshan Lake Mat Lab Dongguan 523808 Peoples R China

Overcoming the strength-ductility trade-off in metals and alloys entails the optimization of the compositions and dedicated microstructural design, which remains experimentally laborious and challenging. Here, a combinatorial method is devised to construct a Cu-Ti alloy library encompassing diverse compositions, microstructures, and mechanical properties, allowing to efficiently identify a copper alloy with an unprecedented yield strength of 3.8 GPa and high deformability. The exceptional properties are attributed to a crystal-glass nano-heterostructure (CGNH) consisting of nanograins, nano twins, and glassy phases. Ultrahigh strength stems from the extreme strengthening of structural-unit refinement and the avoidance of softening caused by grain-boundary sliding through the inclusion of glassy phases between nanograins. Remarkable deformability is associated with the activation of homogeneous flow in nanosized glassy phases, complemented by coordinated nanocrystal rotation. The CGNH architecture offers a potent route to overcome the trade-off between alloy strength and deformability. A modular combinatorial method is developed to create a Cu-Ti alloy library with diverse microstructures and properties. This allows for the efficient identification of a crystal-glass nano-heterostructure (CGNH) comprising nanograins, nanotwins, and glassy phases, achieving exceptional mechanical properties. The CGNH overcomes the alloy strength-deformability trade-off through extreme refinement strengthening, activation of homogeneous flow in glassy phases, and avoidance of grain-boundary sliding. image

关键词： amorphous/crystalline materials combinatorial method heterostructure high strength large deformability

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A catalogue of metallic glass-forming alloy systems

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MATERIALIA 2025年 39卷

作者： Xie, Weijie Li, Mingxing Sun, Yitao Wang, Chao Hu, Liwei Liu, Yanhui Chinese Acad Sci Inst Phys Beijing 100190 Peoples R China Univ Chinese Acad Sci Sch Phys Beijing 100049 Peoples R China Univ Chinese Acad Sci Ctr Mat Sci & Optoelect Engn Beijing 100049 Peoples R China

Rational materials design out of vast compositional space is attractive yet challenging. The data-driven approach has shown promise in accelerating the development of advanced multicomponent alloys, such as metallic glasses. However, data-driven development of glass-forming alloys is limited by the sparse and biased datasets. In this study, we establish the high-throughput experimental database (HED), featuring an unprecedented quantity and diversity of experimental data. This database, encompassing 15,080 materials from 33 alloy systems synthesized and characterized under consistent conditions, provides a robust dataset for the training of machine learning model. The developed model is validated by both literature data and high-throughput experiments, and enables the creation of a catalogue of metallic glass forming alloy systems. The catalogue would serve as a practical reference for efficient design of glass-forming alloys systems.

关键词： Metallic glasses Machine learning combinatorial method Glass forming ability

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Calculation of microscopic nuclear level densities based on covariant density functional theory

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Nuclear Science and Techniques 2023年第9期34卷 118-127页

作者： Kun-Peng Geng Peng-Xiang Du Jian Li Dong-Liang Fang College of Physics Jilin UniversityChangchun 130012China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China

In this study,a microscopic method for calculating the nuclear level density(NLD)based on the covariant density functional theory(CDFT)is *** particle-hole state density is calculated by a combinatorial method using single-particle level schemes obtained from the CDFT,and the level densities are then obtained by considering collective effects such as vibration and *** results are compared with those of other NLD models,including phenomenological,microstatisti-cal and nonrelativistic Hartree–Fock–Bogoliubov combinatorial *** comparison suggests that the general trends among these models are essentially the same,except for some deviations among the different NLD *** addition,the NLDs obtained using the CDFT combinatorial method with normalization are compared with experimental data,including the observed cumulative number of levels at low excitation energies and the measured *** CDFT combinatorial method yields results that are in reasonable agreement with the existing experimental data.

关键词： Nuclear level density Covariant density functional theory combinatorial method

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combinatorial method for direct measurements of the intrinsic hydrogen permeability of separation membrane materials

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JOURNAL OF MEMBRANE SCIENCE 2013年 444卷 70-76页

作者： de Man, S. Gonzalez-Silveira, M. Visser, D. Bakker, R. Schreuders, H. Baldi, A. Dam, B. Griessen, R. Vrije Univ Amsterdam Fac Sci Dept Phys NL-1081 HV Amsterdam Netherlands Leiden Univ Huygens Lab NL-2333 CA Leiden Netherlands Univ Autonoma Barcelona Dept Phys Nanomat & Microsyst Grp Bellaterra 08193 Spain Delft Univ Technol Fac Sci Appl MECS NL-2628 BL Delft Netherlands FOM Inst AMOLF NL-1098 XG Amsterdam Netherlands Stanford Univ Dept Mat Sci & Engn Stanford CA 94305 USA

By means of hydrogenography and an yttrium indicator layer we determine the intrinsic hydrogen permeability in hundreds of compositions of the PdyCu1-y alloy, under exactly the same experimental conditions of temperature and hydrogen pressure. The permeability values obtained with this technique are intrinsic in the sense that they are independent of surface reactions. The room temperature values of the permeability of PdyCu1-y with 0.3 < y < 0.7 exhibit a clear maximum near y = 0.47. The same technique is easily applicable to determine the intrinsic hydrogen permeability of the ternary or quaternary alloy systems. This is explicitly shown for the Pd-Cu-Mo ternary alloys. In this system addition of Mo always leads to a decrease of the intrinsic hydrogen permeability. A similar behavior is observed for Pd-Cu-Ta and Pd-Cu-Ti ternary alloys. (c) 2013 Elsevier B.V. All rights reserved.

关键词： Hydrogen purification Hydrogen permeability Hydrogen membrane combinatorial method Binary and ternary alloys

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