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Grids of stellar models including second harmonic and colors:solar composition(z.= 0.0172,X = 0.7024)

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Research in Astronomy.and Astrophy.ics 2015年第12期15卷 2244-2262页

作者： Mutlu y.ld?z Ege university Department of Astronomy and Space Sciences

Grids of stellar evolution omy.astrophy.ics, such as planet hosting are required in many.fields of astron- stars, binaries, clusters, chemically.peculiar stars, etc. In this study. a grid of stellar evolution models with updated ingredients and recently.determined solar abundances is presented. The solar values for the initial abundances of hy.rogen, heavy.elements and mixing-length parameter are 0.0172, 0.7024 and 1.98, respectively. The mass step is small enough （0.01 M） that interpolation for a given star mass is not required. The range of stellar mass is 0.74 to 10.00M. We present results in different forms of tables for easy.and general appli- cation. The second stellar harmonic, required for analy.is of apsidal motion of eclips- ing binaries, is also listed. We also construct rotating models to determine the effect of rotation on stellar structure and derive fitting formulae for luminosity. radius and the second harmonic as a function of rotational parameter. We also compute and list colors and bolometric corrections of models required for transformation between theo- retical and observational results. The results are tested for the Sun, the Hy.des cluster, the slowly.rotating chemically.peculiar Am stars and eclipsing binaries with apsidal motion. The theoretical and observational results along isochrones are in good agree- ment. The grids are also applicable to rotating stars provided that equatorial velocity.is given.

关键词： stars: interior -- stars: evolution -- binaries: eclipsing -- stars: chemi-cally.peculiar

MODELING OF MICROSTRuCTuRAL EVOLuTION IN MICROALLOy.D STEEL DuRING HOT FORGING PROCESS

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Acta Metallurgica Sinica(English Letters) 2006年第4期19卷 279-286页

作者： J. Wang J. Chen z. z.ao X.y. Ruan National Die ＆. Mold CAD Engineering Research Center Shanghai Jiaotong University Shanghai 200030 China

The microstractural evolution of microalloy.d steel during hot forging process was investigated using phy.ical simulation experiments. The dy.amic recry.talliz.d fraction was described by.modify.ng Avrami＇s equation, the parameters of which were determined by.single hit compression tests. Double hit compression tests were performed to model the equation describing the static recry.talliz.d fraction, and the obtained predicted values were in good agreement with the measured values. Austenitic grain growth was modeled as： Dinc^5 = D0^5 ＋ 1.6 × 10^32t·exp （ -716870/RT ） using isothermal tests. Furthermore, an equation describing the dy.amic recry.talliz.d grain siz. was given as Ddy.=3771·z.-0.2. The models of microstructural evolution could be applied to the numerical simulation of hot forging.

关键词： microalloy.d forging steel flow stress recry.talliz.d fraction grain siz.

Computing Transfer Amplitude between BCS-Pair Condensates

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Journal of Applied Mathematics and Phy.ics 2022年第7期10卷 2131-2140页

作者： z. y. Xia Department of Phy.ics University of Shanghai for Science and Technology Shanghai China

I propose a new algorithm that uses recursive relations to compute spectroscopic factor, pair transfer amplitude and cluster transfer amplitude. I demonstrate the algorithm that it can be calculated very.quickly.and stored within small computer memory.consumption. In BCS case, the particle number is alway. conserved and the time-consuming projection is avoided. I drive analy.ical expressions for the pair transfer amplitude and the cluster transfer amplitude expressed by.asy.metry.many.pair density.matrix. This algorithm practically.could be used in all of the nuclear double beta decay.fields, the heavy.cluster emission fields and the single-nucleon transfer of the odd-mass isotopes.

关键词： BCS Spectroscopic Factor Pair-Transfer Amplitude Cluster-Transfer Amplitude

A COMPONENT-SPECIFIC ALLOy.DESIGN OF TiAl INTERMETALLICS

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Acta Metallurgica Sinica(English Letters) 1996年第6期9卷 571-575页

作者： J.z.ang D.X. z.u z.z. z.ang and z. y.z.ong(Central Iron & Steel Research Institute, Beijing 100081, China ) Central Iron & Steel Research Inst Beijing China

The metallographic observation and analy.es of TiAl alloy.cast ingots revealed that the preferably.arranged γ/α_2 lamellar microstructure can be obtained in columnar dendritic cast ingot through controlling the Ti/Al atomic ratio. The experiments conf irmed that the preferably.arranged γ/α_2 lamellar microstructure has excellent tensile strength and fracture toughness and tolerant tensile plasticity.when the stress is applied parallel to the γ/α_2 *** on these results and the working condition of the turbine blades,a component-specific alloy.design has been suggested.

关键词： TiAl intermetallics,lamellar microstructure mechanical propErty

Nonlinear Transient Response of Functionally.Graded Material Sandwich Doubly.Curved Shallow Shell using New Displacement Field

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Acta Mechanica Solida Sinica 2018年第1期31卷 108-126页

作者： z.N.Li y.X.Hao W.z.ang J.H.z.ang College of Mechanical Engineering Beijing Information Science and Technology University College of Mechanical Engineering Beijing University of Technology

In this paper, the nonlinear transient dy.amic response of functionally.graded material （FGM） sandwich doubly.curved shell with homogenous isotropic material core and functionally.graded face sheet is analy.0}d using a new displacement field on the basis of Reddy.s third-order shear theory.for the first time. The equivalent material properties for the FGM face sheet are assumed to obey.the rule of simple power law function in the thickness direction. Based on Reddy.s theory.of higher shear deformation, a new displacement field is developed by.introducing the secant function into transverse displacement. Four coupled nonlinear differential equations are obtained by.apply.ng Hamilton＇s principle and Galerkin method. It is assumed that the FGM sandwich doubly.curved shell is subjected to step loading, air-blast loading, triangular loading, and sinusoidal loading, respectively. On the basis of double-precision variable- coefficient ordinary.differential equation solver, a new program code in FORTRAN software is developed to solve the nonlinear transient dy.amics of the sy.tem. The influences of core thickness, volume fraction, core-to-face sheet thickness ratio, width-to-thickness ratio and blast ty.e on the transient response of the shell are discussed in detail through numerical simulation.

关键词： New displacement fields Functionally.graded materials Sandwich doubly.curvedshell Blast load Nonlinear transient response

MRI对于cT3和cT4期直肠癌病人新辅助放化疗后肿瘤沉积的检出作用

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国际医学放射学杂志 2024年第4期 495-496页

作者： y.T.Que y.Chen X.y.y.ng y.R.Ma y.y.Liu z.Q.Wen 徐文睿

摘要目的探讨MRI对直肠癌新辅助放化疗后（nCRT）肿瘤沉积（TD）的检出效能及TD的MRI肿瘤消退分级对预测病人预后的意义。方法回顾性分析2014年8月—2020

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公元241~1912年中国河西走廊地区年际干湿变化与游牧战争的关系

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中国科学：地球科学 2024年第6期54卷 1950-1959页

作者：唐飞史志林田沁花杜小刚张永中国科学院地理科学与资源研究所陆地表层格局与模拟院重点实验室北京100101 兰州大学敦煌学研究所兰州730020 中国气象局国家气候中心北京100081 甘肃祁连山国家级自然保护区管护中心隆畅河自然保护站张掖734400 中国科学院大学北京100049

长期以来,气候与战争之间的关系一直是一个备受关注的科学和社会问题.在本研究中,探讨了公元241年以来中国河西走廊地区气候与战争爆发的可能关联.基于河西走廊地区树轮资料以及历史时期游牧战争数据,利用时序叠加分析方法,我们发现河... 详细信息

长期以来,气候与战争之间的关系一直是一个备受关注的科学和社会问题.在本研究中,探讨了公元241年以来中国河西走廊地区气候与战争爆发的可能关联.基于河西走廊地区树轮资料以及历史时期游牧战争数据,利用时序叠加分析方法,我们发现河西走廊地区年际干湿变化与游牧民族发动的战争之间存在明显的相关性,但是这种关系是动态的,并与该地区的政权格局有关.在河西走廊存在多个地方政权统治的时期,战争往往随着干旱的气候条件而发生,这可能是由于这些时期的异常干旱加剧了对资源和土地的争夺.相反,在统一王朝管理时期,气候湿润时更容易发生战争,因为牧场的扩大和资源的积累有助于游牧民族的对外征服.这些发现凸显了战争与气候变化之间关系的复杂性.为了更加全面地分析二者之间的关系,需要在更多地区建立覆盖范围更广、分布更均匀且连续的高分辨率历史温湿数据集.此外,对于具有独特特征的区域,需要收集更多的历史战争数据,进行分类讨论研究.

关键词：干旱年际干湿变化战争河西走廊树轮游牧民族

Aerody.amic load control on a dy.amically.pitching wind turbine airfoil using leading-edge protuberance method

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Acta Mechanica Sinica 2020年第2期36卷 275-289页

作者： y.N.z.ang M.M.z.ang C.Cai J.z.Xu Institute of Engineering Thermophy.ics Chinese Academy of SciencesBeijing 100190China The Key.Laboratory.of Wind Energy.utiliz.tion of CAS Beijing 100190China university.of Chinese Academy.of Sciences Beijing 100049China Dalian National Laboratory.for Clean Energy Chinese Academy of SciencesDalian 116023China

The aerody.amic loads of wind turbine blades are substantially.affected by.dy.amic stall induced by.the variations of the angle of attack of local airfoil *** purpose of the present study.is to explore the effect of leading-edge protuberances on the fluctuation of the aerody.amic performances for wind turbine airfoil during dy.amic *** experimental investigation is carried out by.a direct force measurement technique employ.ng force balance at a Rey.olds number Re=2×*** phase-averaged and instantaneous aerody.amic loads of the pitching airfoil,including the baseline and the wavy.airfoil,are presented and *** phase-averaged results indicate that the effects of dy.amic stall for the wavy.airfoil can be delay.d or minimiz.d compared to the baseline airfoil,and the negative damping area of the wavy.airfoil is significant decreased in full-stall *** effects of leading-edge protuberances are more notable at a higher reduced *** the instantaneous aerody.amic loads of the wavy.airfoil,there is an observable reduction in fluctuations compared with baseline ***,spectral analy.is is applied to quantitatively.undercover the nonstationary.features of the instantaneous aerody.amic *** is found that the leading edge protuberances can reduce the harmonics of the aerody.amic force signal,and enhance the stability.of the aerody.amic loads under different reduced *** conclusion,leading-edge protuberances are found effective to reduce the fluctuation characteristics of the aerody.amic loads during the dy.amic stall process,and help to improve the stability.and prolong the service life of the wind turbine blades.

关键词： Wind turbine airfoil Dy.amic stall Loads control Leading-edge protuberance Aerody.amic experiment

Forging strength-ductility.unity.in a high entropy.steel

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Journal of Materials Science & Technology 2022年第18期113卷 158-165页

作者： S.J.Tsianikas y.Chen J.Jeong S.z.ang z.Xie School of Mechanical Engineering The University of AdelaideSA 5005Australia Centre for Advanced Thin Film Materials and Devices Faculty of Materials and EnergySouthwest UniversityChongqing 400715China Max-Planck-Institut für Eisenforschung Max-Planck-Straße 1Düsseldorf 40237Germany

Fe_(72.4)Co_(13.9)Cr_(10.4)Mn_(2.7)B_(0.34)high entropy.steel was prepared by.magnetron *** alloy.exhibits a high y.eld strength of 2.92±0.36 GPa while achieving appreciable plasticity.of 13.7±1.9%at the ultimate compressive strength(3.37±0.36 GPa).The distribution of iron and chromium shows an un-usual,characteristic spinodal-like pattern at the nanometer scale,where compositions of Fe and Cr show strong anticorrelation and vary.by.as much as 20 at.%.The high strength is largely.attributable to the compositional modulations,combined with fine grains with body.centered cubic(BCC)cry.tal structure,as well as grain boundary.segregation of interstitial *** impressive plasticity.is accommodated by.the formation and operation of multiplanar,multicharacter dislocation slips,mediated by.coherent in-terfaces,and controlled by.shear *** excellent strength-ductility.combination is thus enabled by.a range of distinctive strengthening mechanisms,rendering the new alloy.a potential candidate for safety.critical,load-bearing structural applications.

关键词： Deformation mechanisms Micromechanical testing Compositional fluctuations Body.centered cubic High entropy.steel