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Science China(Physics,Mechanics & Astronomy) 2012年第7期55卷 1253-1257页

作者： MA ChunLan ZANG TaoCheng WANG XiaoDan School of Mathematics and Physics Suzhou University of Science and TechnologySuzhou 215009China

The effects of hydrostatic pressure of SrWeO3 are investigated by means of generalized gradient approximation （GGA） plus on-site Coulomb interaction corrections （GGA＋U） method within the framework of density functional theory （DFT）. Magnetic phase diagrams and structural parameters of SrTcO3 as a function of pressure are predicted. The magnetic ground state of SrTcO3 is found to keep in a G-type antiferromagnetic （G-AFM） structure under the pressure varying from 0 to 100 GPa. With the increase of the pressure, magnetic exchange energy increases, indicating a higher magnetic ordering temperature for SrTcO3 under a larger pressure. Besides the volume of the unit cell, lattice constants, and the bond length, the angles between typical Tc-O-Tc and Sr-O-Sr also decrease with the pressure, leading to strong structural distortions. Very obvious displace- ments of Sr and O atoms are observed under the pressure. Our work provides necessary understanding on electronic structures of SrTcO3 under high pressures.

关键词： crystal structures semiconductors magnetic materials hydrostatic pressure first-principles calculations

Corrosion form transition of mooring chain in simulated deep-sea environments:Remarkable roles of dissolved oxygen and hydrostatic pressure

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Journal of Materials Science & Technology 2023年第31期162卷 118-130页

作者： Xuewei Zhang Weijie Wu Yuan Li Jinxu Li Lijie Qiao Corrosion and Protection Center Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China

The corrosion form and mechanical properties deterioration of mooring chain steel in simulated deep-sea environments were *** the increase of ocean depth,not only the pressure increases,but also the dissolved oxygen content *** two factors affect corrosion evolution of mooring chain steel in simulated deep-sea environments,which was studied for the first *** with uniform corrosion of mooring chain steel in shallow sea with sufficient oxygen,low dissolved oxygen leads to the corrosion dominated by pitting with pit ***,hydrostatic pressure distinctly accelerates pitting initiation and *** higher the hydrostatic pressure is,the more serious the pitting *** failure mechanism of unstressed mooring chain steel serving in simulated deep-sea environments,both absorbed hydrogen and corrosion morphology can degrade the ductility of mooring chain steel,in which the leading factor depends on the service *** severe pitting is the main factor and causes remarkable ductility loss of the steel after long-term *** hydrogen plays an important role on elongation loss in early stage.

关键词： High-strength low-alloy steel Dissolved oxygen hydrostatic pressure Pitting corrosion Failure mechanism

The role of hydrostatic pressure on the metal corrosion in simulated deep-sea environments—a review

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Journal of Materials Science & Technology 2022年第17期112卷 230-238页

作者： Rui Liu Li Liu Fuhui Wang Shenyang National Laboratory for Materials Science Northeastern UniversityNO.3-11 Wenhua RoadShenyang 110819China

This paper reviewed the corrosion behavior of metals in simulated deep-water environments and briefly discussed the effect of hydrostatic pressure on the different corrosion types for the active and the passive alloys.A consensus on the corrosion mechanism is that hydrostatic pressure accelerates the dissolution kinetics,changes the chemical compositions of the product layer or passive films,and promotes the adsorption of Cl^(-)on the metal *** addition,a newly-developed mechanism that hydrostatic pressure facilitates the dissolution process by thinning the electric double layer was reviewed,the synergistic effect of hydrostatic pressure and tensile stress on the stress corrosion cracking was discussed,and the modified coating with chemical bonding interface to prolong the service life in this environment was introduced.

关键词： Corrosion hydrostatic pressure Deep-sea environments

Dynamic ModeⅡfracture behavior of rocks under hydrostatic pressure using the short core in compression(SCC)method

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International Journal of Mining Science and Technology 2021年第5期31卷 927-937页

作者： Wei Yao Ying XuChonglang Wang Kaiwen Xia Mikko Hokka State Key Laboratory of Hydraulic Engineering Simulation and Safety School of Civil EngineeringTianjin UniversityTianjin 300072China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China Engineering Materials Science Faculty of Engineering and Natural SciencesTampere University(TAU)POB 589FI-33014 TampereFinland Department of Civil&Mineral Engineering University of TorontoTorontoON M5S 1A4Canada

The shear failure of rocks under both a static triaxial stress and a dynamic disturbance is common in deep underground engineering and it is therefore essential for the design of underground engineering to quantitively estimate the dynamic ModeⅡfracture toughness KⅡCof rocks under a triaxial stress ***,the method for determining the dynamic KⅡCof rocks under a triaxial stress has not been developed *** an optimal sample preparation,the short core in compression(SCC)method was designed and verified in this study to measure the dynamic KⅡCof Fangshan marble(FM)subjected to different hydrostatic pressures through a triaxial dynamic testing *** formula for calculating the dynamic KⅡCof the rock SCC specimen under hydrostatic pressures was obtained by using the finite element method in combination with secondary *** experimental results indicate that the failure mode of the rock SCC specimen under a hydrostatic pressure is the shear fracture and the KⅡCof FM increases as the loading *** addition,at a given loading rate the dynamic rock KⅡCis barely affected by hydrostatic *** important observation is that the dynamic fracture energy of FM enhances with loading rates and hydrostatic pressures.

关键词： Loading rate Finite element method ModeⅡfracture toughness Fangshan marble hydrostatic pressure Short core in compression

Mechanical Properties and Deformation Mechanisms of Metallic Glasses Under hydrostatic pressure

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Acta Mechanica Solida Sinica 2023年第3期36卷 390-404页

作者： Haiming Lu Yao Tang Fanheng Jiang Panpan Wan Haofei Zhou Center for X-Mechanics Department of Engineering MechanicsZhejiang UniversityHangzhou 310027China

Metallic glasses(MGs)are promising structural materials with high strength,large elastic strain limit and enhanced wear *** the way to tune the mechanical performance of MGs,numerous efforts have been devoted to investigating the effect of hydrostatic pressure(σh)on the mechanical properties and deformation mechanisms of *** application of sufficiently large magnitudes ofσh to MGs has been considered a feasible way to improve strength and delocalize plastic deformation in *** this paper,we review recent studies on pressure-dependent thermodynamic properties,mechanical strength and hardness,as well as elevated ductility of MGs due to the pressure-induced change of deformation and failure *** of intriguing mechanical behaviors of MGs,and the corresponding theoretical modeling and atomistic understanding of plastic deformation in MGs under pure hydrostatic pressure and more general stress states are *** findings not only deepen the understanding of pressure-dependent mechanical behaviors of MGs,but also point out the potential of tuning mechanical behaviors of MGs through stress engineering.

关键词： Metallic glass hydrostatic pressure Mechanical property Deformation mechanism Microstructure

Large enhancement of magnetocaloric effect induced by dual regulation effects of hydrostatic pressure in Mn_(0.94)Fe_(0.06)NiGe compound

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Journal of Materials Science & Technology 2022年第19期114卷 73-80页

作者： He Zhou Dekun Wang Zhe Li Junzhuang Cong Ziyuan Yu Shuo Zhao Peng Jiang Daoyong Cong Xinqi Zheng Kaiming Qiao Hu Zhang School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China College of Physics and Electronic Engineering Key Laboratory for Advanced Functional and Low Dimensional Materials of Yunnan Higher Education InstituteQujing Normal UniversityQujing 655011China MultiFields Technologies(Beijing)Co.Ltd. Beijing 100190China State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China

MM'X(M,M'=transition metals,X=carbon or boron group elements)compounds could exhibit large magnetocaloric effect due to the magnetostructural transition,and the composition regulation has been widely studied to realize the magnetostructural ***,the magnetostructural transition is also sensitive to the ***,the effect of hydrostatic pressure on magnetostructural transformation and magnetocaloric effect has been investigated in Mn_(0.94)Fe_(0.06)NiGe *** regulation effect of lowering structural transition temperature and strengthening ferromagnetic(FM)state of martensite is realized by applying hydrostatic pressure,which would greatly improve the magnetocaloric effect of Mn_(0.94)Fe_(0.06)NiGe ***,the first-principles calculations have also been performed to discuss the origin of the regulation effect under hydrostatic pressure,and it indicates that the hydrostatic pressure can stabilize the hexagonal structure and decrease the structural transition *** maximum isothermal entropy change increases by 109%from 4.3 J/(kg K)under 0 GPa to 9.0 J/(kg K)under 0.402 GPa for a magnetic field change of 0-3 *** work proves that the hydrostatic pressure is an effective method to regulate the magnetostructural transition and enhance magnetocaloric effect in MM'X compounds.

关键词： Magnetocaloric effect Magnetostructural transition hydrostatic pressure Magnetic properties

Restoration of Ultimate Strength of Dented Hemispheres Under External hydrostatic pressure

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China Ocean Engineering 2022年第3期36卷 500-507页

作者： HUANG Chen ZHANG Jian WANG Fang DI Chen-yang School of Mechanical Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China Shanghai Engineering Research Center of Hadal Science and Technology Shanghai Ocean UniversityShanghai 201306China

This study aimed to restore the ultimate strength of dented stainless-steel hemispheres with a radius of 90 mm and a thickness of 0.86 *** of the hemispheres were subjected to external hydrostatic *** stainless-steel stiffened caps were used to eliminate the effect of indention on the ultimate *** caps had a radius of 36 mm,a thickness of 0.76 mm,and a height of 10.44 *** hemispherical samples,including two intact hemispheres,two dented hemispheres without stiffening,and two dented hemispheres with stiffening,were *** hemi-sphere was geometrically measured for shape and thickness,hydrostatically tested for destruction,and numerically evaluated for *** experimental and numerical data agreed well with each *** a result,a spherical cap can effectively restore the ultimate strength of dented hemispheres under external hydrostatic *** proposed restoration approach can be used to strengthen underwater pressure hulls with large local geometric imperfections.

关键词： hemisphere restoration ultimate strength hydrostatic pressure buckling

Buckling of composite cylindrical shells with ovality and thickness variation subjected to hydrostatic pressure

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Defence Technology（防务技术） 2022年第5期18卷 862-875页

作者： Zhun Li Ke-chun Shen Xin-hu Zhang Guang Pan School of Marine Science and Technology Northwestern Polytechnical UniversityXi'an710072China Key Laboratory for Unmanned Underwater Vehicle Northwestern Polytechnical UniversityXi'an710072China Structural Ceramics and Composites Engineering Research Center Shanghai Institute of CeramicsChinese Academy of SciencesShanghai200050China

The initial geometric imperfection is one of the primary factors affecting the buckling behaviors of composite cylindrical shells under hydrostatic *** this study,ovality and thickness variations as two representative types of the geometric imperfections are *** measuring the geometric imperfections,a typical carbon fiber reinforced polymers(CFRP)cylindrical shell is tested to obtain the buckling *** buckling behaviors of the shell sample are analyzed in combination with the strain *** using the nonlinear numerical analysis,the buckling shapes of the CFRP cylinder shells with different combinations of ovality and thickness variation are firstly *** rules of influence of such imperfections on the buckling pressure are then obtained by nonlinear regression ***,an empirical formula is proposed to predict the buckling pressure of the composite cylinder shells,and the calculated results from the formula are in good agreement with the numerical results.

关键词： Composite Cylindrical shell Buckling hydrostatic pressure Imperfections

Influence of optical phonons on the electronic mobility in a strained wurtzite AlN/GaN heterojunction under hydrostatic pressure

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Journal of Semiconductors 2009年第8期30卷 4-9页

作者：周晓娟班士良 Department of Physics School of Physical Science and TechnologyInner Mongolia University

A variational method combined with solving the force balance equation is adopted to investigate the influence of strain and hydrostatic pressure on electronic mobility in a strained wurtzite AlN/GaN heterojunction by considering the scattering of optical-phonons in a temperature ranges from 250 to 600 K. The effects of conduction band bending and an interface barrier are also considered in our calculation. The results show that electronic mobility decreases with increasing hydrostatic pressure when the electronic density varies from 1.0 × 1012 to 6.5 × 1012 cm-2. The strain at the heterojunction interface also reduces the electronic mobility, whereas the pressure influence becomes weaker when strain is taken into account. The effect of strain and pressure becomes more obvious as temperature increases. The mobility first increases and then decreases significantly, whereas the strain and hydrostatic pressure reduce this trend as the electronic density increases at a given temperature （300 K）. The results also indicate that scattering from half space phonon modes in the channel side plays a dominant role in mobility.

关键词： hydrostatic pressure strained AlN/GaN heterojunction electronic mobility optical-phonon scattering

Effect of hydrostatic pressure on LPSO Kinking and Microstructure Evolution of Mg–11Gd–4Y–2Zn–0.5Zr Alloy

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Acta Metallurgica Sinica(English Letters) 2021年第2期34卷 248-264页

作者： Ce Zheng Shuai-Feng Chen Rui-Xue Wang Shi-Hong Zhang Ming Cheng Institute of Metal Research Chinese Academy of SciencesShenyang 110016China University of Chinese Academy of Sciences Beijing 100049China Department of Materials Science and Engineering and Research Institute of Advanced Materials(RIAM) Seoul National UniversitySeoul 08826Republic of Korea

Two different kinds of hot compressions,namely normal-compression and can-compression,were performed on the Mg–11 Gd–4 Y–2 Zn–0.5 Zr alloy,featured with long period stacking ordered(LPSO)*** kinking behavior of LPSO phase and microstructure evolution was investigated to clarify the effect of levels of imposed hydrostatic *** results suggest that the LPSO phases including both the intragranular 14 H-LPSO phase and intergranular 18 R-LPSO phase suffer severe kinking behavior under higher hydrostatic pressure induced by can-compression,which is firstly characterized with more kinking times and smaller relative kinking *** main reason for such enhanced LPSO kinking during cancompression may be mainly ascribed to the higher dislocation density under a higher level of hydrostatic ***,a competitive relationship between the kink behaviors of intergranular 18 R-LPSO phase and intragranular 14 H-LPSO phase was *** is,the intergranular 18 R-LPSO phase only kinks obviously on the condition that the surrounded intragranular 14 H-LPSO phase scarcely *** contrast to the distinctive kinking of LPSO phase,the dynamic recrystallization(DRX)mechanism shows less dependence on the hydrostatic ***,similar DRX fractions and crystallographic texture were attained for two compression processes owing to the similar operation of deformation mode.

关键词： Magnesium alloy hydrostatic pressure Long period stacking ordered(LPSO)phase Kinking Dynamic recrystallization