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Quantitative characterizations of anisotropic dynamic properties in organic-rich shale with different kerogen content

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Petroleum Science 2024年第2期21卷 855-865页

作者： Jian-Yong Xie Yan-Ping Fang Xing-Hua Wu Jian'er Zhao Jun-Cheng Dai Jun-Xing Cao Ji-Xin Deng State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Chengdu University of TechnologyChengdu610059SichuanChina Key Lab of Earth Exploration&Information Techniques of Ministry of Education Geophysical InstituteChengdu University of TechnologyChengdu610059SichuanChina PetroChina Southwest Oil&Gasfield Company Chengdu610017SichuanChina

Understanding the quantitative responses of anisotropic dynamic properties in organic-rich shale with different kerogen content(KC)is of great significance in hydrocarbon exploration and development.Conducting controlled experiments with a single variable is challenging for natural shales due to their high variations in components,diagenesis conditions,or pore fluid.We employed the hot-pressing technique to construct 11 well-controlled artificial shale with varying KC.These artificial shale samples were successive machined into prismatic shape for ultrasonic measurements along different directions.Observations revealed bedding perpendicular P-wave velocities are more sensitive to the increasing KC than bedding paralleling velocities due to the preferential alignments of kerogen.All elastic stiffnesses except C_(13)are generally decreasing with the increasing KC,the variation of C_(1) and C_(33)on kerogen content are more sensitive than those of C_(44)and C_(66).Apparent dynamic mechanical parameters(v and E)were found to have linear correlation with the true ones from complete anisotropic equations independent of KC,which hold value towards the interpretation of well logs consistently across formations,Anisotropic mechanical parameters(ΔE and brittlenessΔB)tend to decrease with the reducing KC,withΔB showing great sensitivity to KC variations.In the range of low KC(10%)shale,compilation of data from natural organic rich-shales globally verified the similar systematic relationships that can be empirically used to predict the fraction of KC in shales.

关键词： elastic properties Organic shale Anisotropy Kerogen content Physical modeling

Tunnel-structured willemite Zn_(2)SiO_(4):Electronic structure,elastic,and thermal properties

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Journal of Advanced Ceramics 2022年第8期11卷 1249-1262页

作者： Ruqiao DAI Renfei CHENG Jiemin WANG Chao ZHANG Cuiyu LI Hailong WANG Xiaohui WANG Yanchun ZHOU Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Advanced Computing East China Sub-center Suma Technology Company LimitedKunshan 215300China School of Material Science and Engineering Zhengzhou UniversityZhengzhou 450001China Science and Technology on Advanced Functional Composite Laboratory Aerospace Research Institute of Materials&Processing TechnologyBeijing 100076China

Willemite Zn_(2)SiO_(4)crystallizes in such a way that Zn and Si are tetrahedrally coordinated with O in an ionic–covalent manner to form ZnO_(4)and SiO_(4)tetrahedra as the building units.The tetrahedra are corner-sharing,of which one SiO_(4)tetrahedron connects eight ZnO_(4)tetrahedra,and one ZnO_(4)tetrahedron links four ZnO_(4)tetrahedra and four SiO_(4)tetrahedra.The unique crystallographic configuration gives rise to parallel tunnels with a diameter of 5.7Åalong the c-axis direction.The tunnel structure of Zn_(2)SiO_(4)definitely correlates with its interesting elastic and thermal properties.On the one hand,the elastic modulus,coefficient of thermal expansion(CTE),and thermal conductivity are low.Zn_(2)SiO_(4)has low Vickers hardness of 6.6 GPa at 10 N and low thermal conductivity of 2.34 W/(m·K)at 1073 K.On the other hand,the elastic modulus and CTE along the c-axis are significantly larger than those along the a-and b-axes,showing obvious elastic and thermal expansion anisotropy.Specifically,the Young’s modulus along the z direction(Ez=179 GPa)is almost twice those in the x and y directions(Ex=Ey=93 GPa).The high thermal expansion anisotropy is ascribed to the empty tunnels along the c-axis,which are capable of more accommodating the thermal expansion along the a-and b-axes.The striking properties of Zn_(2)SiO_(4)in elastic modulus,hardness,CTE,and thermal conductivity make it much useful in various fields of ceramics,such as low thermal expansion,thermal insulation,and machining tools.

关键词： Zn_(2)SiO_(4) electronic structure elastic properties thermal expansion thermal conductivity

First-Principles Investigation on Phase Stability,elastic and Magnetic properties of Boron Doping in Ni-Mn-Ti Alloy

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Acta Metallurgica Sinica(English Letters) 2022年第7期35卷 1175-1183页

作者： Chenchen Xiong Jing Bai Yansong Li Jianglong Gu Xinzeng Liang Ziqi Guan Yudong Zhang Claude Esling Xiang Zhao Liang Zuo Key Laboratory for Anisotropy and Texture of Materials Northeastern UniversityShenyang 110819China School of Resources and Materials Northeastern University at QinhuangdaoQinhuangdao 066004China State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province Qinhuangdao 066004China Laboratoire d’Étude des Microstructures et de Mécanique des Matériaux UMR 7239LEM3CNRSUniversity of Lorraine57045 MetzFrance

The all-d-metal Ni-Mn-Ti Heusler alloy has giant elastocaloric eff ect and excellent mechanical properties,which is diff erent from the conventional Ni-Mn-based Heusler alloys.In this work,the preferred site occupation,phase stability,martensitic transformation,magnetic properties,and electronic structure of the B-doped Ni_(2)Mn_(1.5)Ti_(0.5)alloys are systematically investigated by the fi rst-principles calculations.The results show that B atoms preferentially occupy the octahedral interstitial.The doped B atoms tend to exist in the(Ni_(2)Mn_(1.5)Ti_(0.5))_(1-x)B_(x)(x=0.03,0.06,0.09)alloy in the form of aggregation distribution,and the martensitic transformation temperature decreases with the increase in the B content.For octahedral interstitial doping,the toughness and plasticity of the(Ni_(2)Mn_(1.5)Ti_(0.5))_(1-x)B_(x) alloys decrease,but the strength and rigidity are greatly enhanced.This is because a small part of the d-d hybridization in ternary Ni-Mn-Ti alloy is replaced by the p-d hybridization in Ni-Mn-Ti-B alloy.

关键词： Ni-Mn-Ti First-principles calculations Phase stability elastic properties Magnetic properties

Hybrid DFT study of structural,electronic,magnetic and elastic properties of laves phase binary intermetallics RFe_(2)(R=La,Ce,Pr and Nd)

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稀土学报:英文版 2023年第9期41卷 1367-1375,I0004页

作者： Murad Murad Zahid Ali Muhammad Idrees Centre for Computational Materials Science Department of PhysicsUniversity of MalakandChakdaraDir(Lower)18800KPPakistan

Hybrid density functional theory was used to investigate the structural,electronic,magnetic and elastic properties of the Laves phase binary intermetallics RFe_(2)(R=La,Ce,Pr and Nd) in C_(15) crystal structure.The calculated lattice constants of these materials are found in good agreement with the experiments.The band structures and density of states distribution confirm the metallic nature of all these intermetallics.The optimized energies in different magnetic phases and magnetic susceptibilities by postDFT treatments confirm that all the understudy compounds are ferromagnetic in nature.elastic parameters were calculated from the cubic elastic coefficients C_(11),C_(12) and C_(44).The elastic properties reveal that these intermetallics are incompressible,ductile,elastically anisotropic and mechanically stable.Based on the metallic nature and ferromagnetic properties,it is expected that these intermetallics are suitable materials for spintronic technology.

关键词： Intermetallics Laves phase Density functional theory Electronic band structures Magnetic properties elastic properties

Elaborating strengthen mechanism of Pt-Ir solid solution superalloy at finite temperature

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Rare Metals 2024年第3期43卷 1243-1256页

作者： Wei Yu Xiao-Yu Chong Yun-Xuan Zhou Meng-Di Gan Ying-Xue Liang Yan Wei Ai-Min Zhang Chang-Yi Hu Xing-Yu Gao Li Chen Hai-Feng Song Jing Feng Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming650093China Yunnan Precious Metals Laboratory Co.LTD Kunming650106China Laboratory of Computational Physics Institute of Applied Physics and Computational MathematicsBeijing100088China

Pt-Ir alloy is potential superalloys used above 1300℃because of their high strength and creep resistance.However,the ductility of Pt-Ir alloy has rapidly deteriorated with the increase of Ir,resulting in poor machinability.This work quantitatively evaluated the solid solution strengthening(SSS)and grain refinement strengthening(GRS)of Pt-Ir alloy using first-principles calculations combined with experimental characterization.Here,the stretching force constants in the second nearest neighbor region(SFC^(2nd))of pure Ir(193.7 eV·nm^(-2))are 3.40 times that of pure Pt(57.0 eV·nm^(-2)),i.e.,the interatomic interaction is greatly enhanced with the increase of Ir content,which leads to the decrease of ductility,and modulus misfit plays a dominant role in SSS.Then,the physical mechanisms responsible for the hardness(H_(V))of Pt-Ir alloy,using the power-law-scaled function of electron work function coupled SSS and GRS,are attributed to the electron redistribution caused by different Ir content.Furthermore,a thorough assessment of the thermodynamic characteristics of Pt-Ir binary alloy was conducted,culminating in development of a mapping model that effectively relates enmposition,temperature and strength.The results revealed that the compressive strength incrcases with the Ir content,and the highest strength was observed in Pt_(0.25)Ir_(0.75).This study provides valuable insights into the Pt-Ir alloy system.

关键词： elastic properties Phonon Solid solution strengthen Force constants CALPHAD

elastic properties of CaCO3 high pressure phases from first principles

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Chinese Physics B 2017年第8期26卷 587-594页

作者：黄丹刘红侯明强谢梦雨鹿亚飞刘雷易丽崔月菊李营邓力维杜建国 CEA Key Laboratory of Earthquake Prediction(Institute of Earthquake Science) China Earthquake Administration(CEA)Beijing 100036China National Key Laboratory of Shock Wave and Detonation Physics Institute of Fluid PhysicsChina Academy of Engineering PhysicsMianyang 621900China Center for High Pressure Science and Technology Advanced Research Shanghai 201203China Institute of Geology and Geophysics Chinese Academy of SciencesBeijing 100029China

elastic properties of three high pressure polymorphs of CaCO_3 are investigated based on first principles calculations.The calculations are conducted at 0 GPa–40 GPa for aragonite, 40 GPa–65 GPa for post-aragonite, and 65 GPa–150 GPa for the P2_1/c-h-CaCO_3 structure, respectively. By fitting the third-order Birch–Murnaghan equation of state（EOS）, the values of bulk modulus K_0 and pressure derivative K~＇_0 are 66.09 GPa and 4.64 for aragonite, 81.93 GPa and 4.49 for post-aragonite, and 56.55 GPa and 5.40 for P2_1/c-h-CaCO_3, respectively, which are in good agreement with previous experimental and theoretical data. elastic constants, wave velocities, and wave velocity anisotropies of the three highpressure CaCO_3 phases are obtained. Post-aragonite exhibits 25.90%–32.10% V_P anisotropy and 74.34%–104.30% V_S splitting anisotropy, and P2_1/c-h-CaCO_3 shows 22.30%–25.40% V_Panisotropy and 42.81%–48.00% V_S splitting anisotropy in the calculated pressure range. Compared with major minerals of the lower mantle, CaCO_3 high pressure polymorphs have low isotropic wave velocity and high wave velocity anisotropies. These results are important for understanding the deep carbon cycle and seismic wave velocity structure in the lower mantle.

关键词： CaCO3 elastic properties wave velocity anisotropy first principles

elastic properties of Nb-based alloys by using the density functional theory

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Chinese Physics B 2012年第1期21卷 357-362页

作者：刘增辉尚家香 School of Materials Science and Engineering Beihang University

A first-principles density functional approach is used to study the electronic and the elastic properties of Nb15X （X = Ti, Zr, Hf, V, Ta, Cr, Mo, and W） alloys. The elastic constants cn and c12, the shear modulus CI, and the elastic modulus E（lOO） are found to exhibit similar tendencies, each as a function of valence electron number per atom （EPA）, while c44 seems unclear. Both cu and c12 of Nb15X alloys increase monotonically with the increase of EPA. The C/ and E000） also show similar tendencies. The elastic constants （except c44） increase slightly when alloying with neighbours of a higher d-transition series. Our results are supported by the bonding density distribution. When solute atoms change from Ti（Zr, Hf） to V（Ta） then to Cr（Mo, W）, the bonding electron density between the central solute atom and its first neighbouring Nb atoms is increased and becomes more anisotropic, which indicates the strong interaction and thus enhances the elastic properties of Nb-Cr（Mo, W） alloys. Under uniaxial {100） tensile loading, alloyed elements with less （more） valence electrons decrease （increase） the ideal tensile strength.

关键词： Nb-based alloys elastic properties density functional calculations

A method of determining effective elastic properties of honeycomb cores based on equal strain energy

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Chinese Journal of Aeronautics 2017年第2期30卷 766-779页

作者： Qiu Cheng Guan Zhidong Jiang Siyuan Li Zengshan School of Aeronautic Science and Engineering Beihang University Bejing 100083 China

A computational homogenization technique（CHT） based on the finite element method（FEM） is discussed to predict the effective elastic properties of honeycomb structures.The need of periodic boundary conditions（BCs） is revealed through the analysis for in-plane and out-of-plane shear moduli of models with different cell numbers.After applying periodic BCs on the representative volume element（RVE）,comparison between the volume-average stress method and the boundary stress method is performed,and a new method based on the equality of strain energy to obtain all non-zero components of the stiffness tensor is proposed.Results of finite element（FE） analysis show that the volume-average stress and the boundary stress keep a consistency over different cell geometries and forms.The strain energy method obtains values that differ from those of the volume-average method for non-diagonal terms in the stiffness matrix.Analysis has been done on numerical results for thin-wall honeycombs and different geometries of angles between oblique and vertical walls.The inaccuracy of the volume-average method in terms of the strain energy is shown by numerical benchmarks.

关键词： elastic properties Homogenization Honeycomb Strain energy Unit cells

Stability, elastic anisotropy, and electronic properties of Ca2C3

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Chinese Physics B 2017年第6期26卷 295-300页

作者：张权魏群闫海燕朱轩民张军琴贾晓菲姚荣辉 School of Microelectronics Xidian University Xi'an 710071 China School of Physics and Optoelectronic Engineering Xidian University Xi'an 710071 China College of Chemistry and Chemical Engineering Baoji University of Arts and Sciences Baoji 721013 China Department of Electronic and Information Engineering Ankang University Ankang 725000 China

The systematic investigations of the mechanical, elastic, and electronic properties, and stability of the newly synthesized monoclinic C2/m-Ca2C3 are performed, based on the first-principles calculations. Ca2C3 is found to be mechanically and dynamically stable only from 0 GPa to 24 GPa. The elastic anisotropy studies show that Ca2C3 exhibits the elastic anisotropy increasing with the augment of pressure. Furthermore, using the HSE06 hybrid functional, the electronic properties of Ca2C3 under pressure are calculated. The structure can be regarded as a quasi-direct band gap semiconductor, and the pressure-induced direct-indirect band gap transition is studied in detail.

关键词： carbides first-principles calculations elastic properties electronic structure