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The Gamow shell model with realistic interactions:a theoretical framework for ab initio nuclear structure at drip-lines

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Communications in Theoretical Physics 2022年第9期74卷 284-298页

作者： Nicolas Michel jianguo li Furong Xu CAS Key Laboratory of High Precision Nuclear Spectroscopy Institute of Modern PhysicsChinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijingChina School of Physics and State Key Laboratory of Nuclear Physics and TechnologyPeking UniversityBeijing 100871China

Ab initio approaches are among the most advanced models to solve the nuclear many-body *** particular,the no-core-shell model and many-body perturbation theory have been recently extended to the Gamow shell model framework,where the harmonic oscillator basis is replaced by a basis bearing bound,resonance and scattering states,*** Berggren *** continuum coupling is included at basis level and as configuration mixing takes care of internucleon correlations,halo and resonance nuclei can be properly described with the Gamow shell *** development of the no-core Gamow shell model and the introduction of the■-box method in the Gamow shell model,as well as their first ab initio applications,will be reviewed in this *** compared to models using harmonic oscillator bases will be shortly *** current power and limitations of ab initio Gamow shell model will also be discussed,as well as its potential for future applications.

关键词： binding energy lifetimes nucleon-nucleon interactions shell model continuum coupling

Effects of Ca(Y)-Si modifier on interface morphology and solute segregation during directional solidification of an austenite medium Mn steel

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Journal of University of Science and Technology Beijing 2005年第4期12卷 335-339页

作者： Gaofei liang Zhenming Xu jianguo li School of Environmental Science and Engineering Shanghai Jiaotong University Shanghai 200240 China

The austenite medium Mn steel modified with controlled additions of Ca, Y, Si were directionally solidified using the vertical Bridgman method to study the effects of Ca（Y）-Si modifier on the solid-liquid （S-L） interface morphology and solute segregation. The interface morphology and the C and Mn segregation of the steel directionally solidified at 6.9 μtrn/s were investigated with an image analysis and a scanning electron microscope equipped with energy dispersive X-ray analysis. The 0.5wt% Ca-Si modified steel is solidified with a planar S-L interface. The interface of the 1.0wt% Ca-Si modified steel is similar to that of the 0.5wt% Ca-Si modified steel, but with larger nodes. The 1.5wt% Ca-Si modified steel displays a cellular growth parttern. The S-L interface morphology of the 0.5wt% Ca-Si＋1.0wt% Y-Si modified Mn steel appears as dendritic interface, and primary austenite dendrites reveal developed lateral branching at the quenched liquid. In the meantime, the independent austenite colonies are formed ahead of the S-L interface. A mechanism involving constitutional supercooling explains the S-L interface evolution. It depends mainly on the difference in the contents of Ca, Y, and Si ahead of the S-L interface. The segregation of C and Mn ahead of the S-L interface enhanced by the modifiers is observed.

关键词： austenite Mn steel modification solid-liquid (S-L) interface morphology solute segregation directional solidification

A Primary Observation on Palynofacies of the Chuangde Section(Late Jurassic-Cretaceous),Gyangze,Southern Tibet

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Acta Geologica Sinica(English Edition) 2007年第6期81卷 1019-1025页

作者： li jianguo GUO Zhenyu Nanjing Institute of Geology and Paleontology Chinese Academy of Sciences Nanjing Jiangsu 210008

A primary study on palynofacies, which concerns the paleoenvironments from the sight of association of sedimentary organic matter preserved in sedimentary rocks, is conducted for a Late Jurassic-Cretaceous succession at Gyangze, southern Tibet. Two palynofacies are recognized, which are formed in different sedimentary environments. The one in the pelagic is infertile in organic productivity and monotonous in component and is dominated by AOMA, while the other, being closely bound up with the slope, is characterized by abundant black phytoclasts that are possibly of algal origin and contains much AOM. The influence of terrestrial input is clear in the latter, for particles generated from terrestrial plants are common. A number of fossil spores and pollen together with some dinocysts are discovered, but they are normally in a bad condition of preservation. Nevertheless, this convinces us that the late Jurassic-Cretaceous succession in the Gyangze area has a potential for palynological stratigraphy. We have also proved that the volume of PM can achieve similar results in presenting the productivity of organic matter as the weight of TOC does. This technique is much easier in the laboratory than that we do with TOC.

关键词： palynofacies paleoenvironment palynomorphs TPM southern Tibet

Effect of Grain Size and Compression Direction on the Hot Deformation Characteristics of High-Cr Ultra-Super-Critical Rotor Steel with Columnar Grains

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Acta Metallurgica Sinica(English Letters) 2023年第5期36卷 803-813页

作者： Yanyang Wu Qiaodan Hu Zongye Ding jianguo li Shanghai Key Laboratory of Materials Laser Processing and Modification School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai200240China School of Mechatronic Engineering and Automation Foshan UniversityFoshan528225China WuYang Iron and Steel Wugang450000China

The columnar grains with a duplex grain size distribution in the ingot increase the difficulty of the hot forging of the as-cast high Cr ultra-super-critical rotor *** hot deformation behaviors of the high Cr steel with different initial grain sizes under various compression directions were *** results show that the hot deformation characteristic is strongly grain size and compression direction *** finer grain size and compression direction perpendicular to the columnar grains increase the flow stress and activation energies of hot deformation,comparing with the large grain and deformation direction parallel to the columnar *** relationships between flow stress and deformation parameters for the different initial structures conform to the established constitutive *** former enhances the critical stress of the dynamic recrystallization(DRX),inhibiting the occurrence of DRX and reducing the dimensions of DRX grains.

关键词： High Cr ultra-super-critical rotor steel Solidification Hot deformation Dynamic recrystallization Critical stress

Spectroscopic factors of resonance states with the Gamow shell model

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Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 38-45页

作者： Mengran Xie jianguo li Nicolas Michel Honghui li Wei Zuo CAS Key Laboratory of High Precision Nuclear Spectroscopy Institute of Modern PhysicsChinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China

We provide an investigation of the spectroscopic factor of resonance states in A=5-8 nuclei,utilizing the Gamow shell model(GSM).Within the GSM,the configuration mixing is taken into account exactly with the shell model framework,and the continuum coupling is addressed via the complex-energy Berggren ensemble,which treats bound,resonance,and non-resonant continuum single-particle states on an equal *** a result,both the configuration mixing and continuum coupling are meticulously considered in the *** first calculate the low-lying states of helium isotopes and isotones with the GSM,and the results are compared with that of ab initio no-core shell model(NCSM)*** results indicate that GSM can reproduce the low-lying resonance states more accurately than the *** this,we delve into the spectroscopic factors of the resonance states as computed through both GSM and NCSM,concurrently conducting systematic calculations of overlap functions pertinent to these resonance ***,the calculated overlap function and spectroscopic factor of6He(01+)■νp3/2→^(7)He(3/2_(1)-)with GSM are compared with the results from ab initio NCSM,variational Monte Carlo,and Green’s function Monte Carlo calculations,as well as available experimental *** results assert that wave function asymptotes can only be reproduced in GSM,where resonance and continuum coupling are precisely addressed.

关键词： spectroscopic factor overlap function resonance states continuum coupling isospin symmetry breaking

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Imaging of Structure Evolution in Solidifying Al–Bi Immiscible Alloys by Synchrotron Radiography

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Journal of Materials Science & Technology 2016年第12期32卷 1321-1325页

作者： Wenquan Lu Shuguang Zhang Wei Zhang jianguo li School of Materials Science and Engineering Shanghai Jiao Tong University School of Environmental Science and Engineering Shanghai Jiao Tong University

Using synchrotron X-ray imaging technique,the segregation evolution in solidifying Al-10 wt% Bi immiscible alloys was investigated at different cooling *** of the cooling rate,most of the Bi solute appeared at the upper part of the sample after *** reason for this Bi enrichment phenomenon is different for different cooling *** Marangoni motion,positive segregation,which has rarely been noticed before,can also make Bi solute transfer to the hot top *** is also found that,bubbles（or pores） appear in solidifying Al-10 wt% Bi alloys,and the number of bubbles（or pores） increases with the increase of the cooling rate,while the size of the bubbles（or pores） decreases.

关键词： Immiscible alloys Segregation Synchrotron radiography Marangoni motion Bubble

An efficient algorithm for generating a spherical multiple-cell grid

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Acta Oceanologica Sinica 2022年第5期41卷 41-50页

作者： Fang Hou Zhiyi Gao jianguo li Fujiang Yu National Marine Environmental Forecasting Center Beijing100081China Met Office ExeterEX13PBUK

This paper presents an efficient algorithm for generating a spherical multiple-cell(SMC)*** algorithm adopts a recursive loop structure and provides two refinement methods:(1)an arbitrary area refinement method and(2)a nearshore refinement *** experiments are carried out,and the results show that compared with the existing grid generation algorithm,this algorithm is more flexible and operable.

关键词： spherical multiple-cell grid wave model WAVEWATCH III grid generation algorithm

Influence of Crystal Orientation on the Morphology of a Single Crystal Superalloy during Directional Solidification

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Journal of Materials Science & Technology 1998年第3期14卷 200-204页

作者： He, Guo li, jianguo Mao, Xiemin Fu, Hengzhi Northwestern Polytech Univ State Key Lab Solidificat Proc Xian 710072 Peoples R China

The solid-liquid (S/L) interfacial morphology of a single crystal superalloy DD8 has been investigated. The evolutionary behavior of cellular morphology with tilted preferred crystallographic orientation near cell-dendrite transition was dynamically observed, and the effect of crystallographic orientation on primary dendritic arm spacing has been examined. The experimental results show that for planar and cellular morphology, no any S/L interfacial anisotropy exists, but near cell-dendrite transition, the S/L interfacial anisotropy appears and gives rise to the cellular crystal fingers tilted from thermal flow direction to preferred crystallographic orientation. The crystal fingers with their preferred orientation parallel to DS growth direction are more stable than that with tilted orientation. For the tilted fingers, the surface on the side facing DS growth direction is less stable than that on the reverse side,the different stability on the two sides will lead to forming unsymmetrical dendritic microstructure. With this increase of tilted angle of preferred crystallographic orientation, the primary dendrite arm spacing decreases. (Edited author abstract) 7 Refs.

关键词： Nickel alloys

Variation characteristics of evaporation in the Gulang River Basin during 1959−2013

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Research in Cold and Arid Regions 2020年第4期12卷 252-260页

作者： TingTing Wang jianguo li ZongXing li School of Economics and Management Lanzhou Jiaotong UniversityLanzhouGansu 730070China Northwest Institute of Eco-Environment and Resources Chinese Academy of SciencesLanzhouGansu 730000China Key Laboratory of Ecohydrology of Inland River Basin Chinese Academy of SciencesLanzhouGansu 730000China

Based on monthly evaporation of two meteorological stations in the Gulang River Basin of China,the inter-annual variation of evaporation during 1959−2013 were analyzed using Mann-Kendall and wavelet *** results demonstrated that the annual evaporation show a fluctuating increase over the past 50 years approximately,with an average increase rate of 4.26 mm per *** overall trend was decrease−increase−*** to the cumulative anomaly curve,the turning point of the annual evaporation occurred in 1979,in which the evaporation increased in the early stage and decreased in the later ***,the seasonal variation of the evaporation shows that it decreased in Spring and Autumn,and increased in Summer and Winter,especially obvious for the *** evaporation abruptly changed in Spring and Summer in 2008 and in Winter in *** addition,all evaporation increased after the ***,the evaporation in Autumn abruptly changed in 1986 and 1999,which show a trend of *** analysis shows that evaporation in Summer and wet season would decrease in the next few years,and in the other seasons would *** on the aforementioned analysis,it can be concluded that increased evaporation is mainly induced by increase of evaporation in dry season,especially in Winter,and this trend to be continued in the future for the Gulang River Basin.

关键词： Gulang River Basin evaporation abrupt changes wavelet analysis