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Chinese Physics B 2019年第12期28卷 237-247页

作者： L wei z X wang J Q Li z Q hu Y Kishimoto Key Laboratory of Materials Modification by Laser Ionand Electron Beams(Ministry of Education)School of PhysicsDalian University of TechnologyDalian 116024China Southwestern Institute of Physics Chengdu 610041China Graduate School of Energy Science Kyoto UniversityGokashoUjiKyoto 1-0011Japan

Nonlinear interaction between tearing modes(TM) and slab ion-temperature-gradient(ITG) modes is numerically investigated by using a Landau fluid model. It is observed that the energy spectra with respect to wavenumbers become broader during the transition phase from the ITG-dominated stage to TM-dominated stage. Accompanied with the fast growth of the magnetic island, the frequency of TM/ITG with long/short wavelength fluctuations in the electron/ion diamagnetic direction decreases/increases respectively. The decrease of TM frequency is identified to result from the effect of the profile flattening in the vicinity of the magnetic island, while the increase of the frequencies of ITG fluctuations is due to the eigenmode transition of ITG induced by the large scale zonal flow and zonal current related to TM. Roles of zonal current induced by the ITG fluctuations in the instability of TM are also analyzed. Finally, the electromagnetic transport features in the vicinity of the magnetic island are discussed.

关键词： magnetic reconnection tearing modes magnetohydrodynamics drift waves nonlinear phenomena

Spectral measurements of hypervelocity flow in an expansion tunnel

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Acta Mechanica Sinica 2019年第1期35卷 24-31,I0002页

作者： C.K.Yuan K.zhou Y.F.Liu z.M.hu z.L.Jiang State Key Laboratory of High-Temperature Gas Dynamic Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Engineering Sciences. University of Chinese Academy of Sciences Beijing 100049China China Academy of Aerospace Aerodynamics Beijing 100074China

Atmospheric reentry vehicles and planetary probes fly through the atmosphere at hypervelocity speed. At such speed, there is a significant proportion of heat load to the vehicle surface due to radiative heating. Accurate prediction needs a good knowledge of the radiation spectrum properties. In this paper, a high-speed camera and spectrograph coupled to an intensified charge-coupled device have bee n impleme nted to inv estigate the rad i at io n flow over a semi-cylinder model. The experiments were carried out in the JF16 expansi on timnel with secondary shock velocity of 7.9 km·s^-1. Results show that the emissio n spectrum comprises several atomic lines and molecular band systems. we give detailed data of the radiation spectrum, shock shape, shock detached distance and radiation intensity varying with space and wavelength. This valuable experimental dataset will be helpful to validate computational fluid dynamics codes and radiation models, which equates to increased prediction accuracy of radiation heating. Also, some suggestions for spectral measurement in hypervelocity flow field were list in the end.

关键词： Spectral measurement Hypervelocity flow Radiation Expansion tunnel

A NOVEL SYNTHESIS OF 3-PHENYL-1H-INDAzOLE DERIVATIVES

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Chinese Chemical Letters 1995年第1期6卷 13-16页

作者： zhong, zQ Qui, Yz zhang, z hu, Hw Nanjing Univ Dept Chem Nanjing 210008 Peoples R China

A facile, novel and one-pol method for the preparation of 3-phenyl-1H-Indazole derivatives in moderate yields by cyclization of the ortho-substituted benzophenone hydrazones in the presence of polyphosphoric acid (PPA...

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Preface: machine-learning approaches for computational mechanics

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Applied Mathematics and Mechanics(English Edition) 2023年第7期44卷 1035-1038页

作者： z.LI Guohui hu zhiliang wANG G.E.KARNIADAKIS Department of Mechanical Engineering Clemson UniversityClemsonSouth Carolina 29634U.S.A. Shanghai Institute of Applied Mathematics and Mechanics School of Mechanics and Engineering ScienceShanghai UniversityShanghai 200072China Division of Applied Mathematics Brown UniversityProvidenceRhode Island 02912U.S.A.

Machine-learning(ML) approaches have gained significant attention in recent years for their potential to revolutionize various scientific research fields,including computational mechanics,materials science,and biomedical *** the field of computational mechanics,various neural network models such as feedforward neural networks,convolutional neural networks.

关键词： neural networks engineering

Detonation initiation developing from the Richtmyer-Meshkov instability

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Acta Mechanica Sinica 2007年第4期23卷 343-349页

作者： H.H.Teng z.L.Jiang z.M.hu LHD.Institute of Mechanics,CAS.Beijing 100080,China LHD Institute of Mechanics CAS Beijing China

Detonation initiation resulting from the Richtmyer-Meshkov instability is investigated numerically in the configuration of the shock/spark-induced-deflagration interaction in a combustive gas mixture. Two-dimensional multi-species Navier-Stokes equations implemented with the detailed chemical reaction model are solved with the dispersion-controlled dissipative scheme. Numerical results show that the spark can create a blast wave and ignite deflagrations. Then, the deflagration waves are enhanced due to the Richtmyer-Meshkov instability, which provides detonation initiations with local environment conditions. By examining the deflagration fronts, two kinds of the initiation mechanisms are identified. One is referred to as the deflagration front acceleration with the help of the weak shock wave, occurring on the convex surfaces, and the other is the hot spot explosion deriving from the deflagration front focusing, occurring on the concave surfaces.

关键词： Hot spot Deflagration front acceleration Detonation initiation Richtmyer-Meshkov instability

Improving Intergranular Stress Corrosion Cracking Resistance in a Fe–18Cr–17Mn–2Mo–0.85N Austenitic Stainless Steel Through Grain Boundary Character Distribution Optimization

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Acta Metallurgica Sinica(English Letters) 2022年第11期35卷 1849-1861页

作者： F.Shi L.Yan J.hu L.F.wang T.z.Li w.Li X.J.Guan C.M.Liu X.w.Li Department of Materials Physics and Chemistry School of Materials Science and EngineeringNortheastern UniversityShenyang 110819China State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819China Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) Northeastern UniversityShenyang 110819China

The grain boundary character distribution(GBCD) optimization and its effect on the intergranular stress corrosion cracking(IGSCC) resistance in a cold-rolled and subsequently annealed Fe-18 Cr-17 Mn-2 Mo-0.85 N high-nitrogen nickel-free austenitic stainless steel were systematically *** results show that stacking faults and planar slip bands appearing at the right amount of deformation(lower than 10%) are beneficial cold-rolled microstructures to the GBCD *** proportion of special boundaries gradually increases in the subsequent stages of recrystallization and grain growth,accompanying with the growth of twin-related domain in the experimental *** this way,the fraction of low ∑ coincidence site lattice(CSL) boundaries can reach as high as 82.85% for the specimen cold-rolled by 5% and then annealed at 1423 K for 72 *** GBCD optimization,low ∑ CSL boundaries and the special triple junctions(J2,J3) of high proportion can greatly hinder the nitride precipitation along grain boundaries and enhance the capability for intergranular crack arrest,thus improving the IGSCC resistance of the experimental steel.

关键词： High-nitrogen austenitic stainless steel Grain boundary character distribution Coincidence site lattice(CSL)grain boundary Electron backscatter diff raction(EBSD) Intergranular stress corrosion cracking

First-order phase transition and unexpected rigid rotation mode in hybrid improper ferroelectric(La,Al)co-substituted Ca_(3)Ti_(2)O_(7) ceramics

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Journal of Materiomics 2019年第4期5卷 618-625页

作者： z.z.hu J.J.Lu B.H.Chen T.T.Gao X.Q.Liu w.wen X.M.Chen Laboratory of Dielectric Materials School of Materials Science and EngineeringZhejiang UniversityNo.38 Zheda RoadHangzhou310027China Shanghai Synchrotron Radiation Facility Shanghai Institute of Applied PhysicsChinese Academy of SciencePudong New AreaShanghai201204China

Ca_(3)Ti_(2)O_(7) with Ruddlesden-Popper structure exhibits the largest polarization among the known hybrid improper ***,the high Curie temperature impedes the thorough study of phase transition through dielectric *** to the previous theoretical design rule,the Curie temperature can be suppressed by increasing the tolerance ***,in the present work,high-quality Ca_(3-x)LaxTi_(2-x)Al_(x)O_(7)(x=0.0,0.1,0.2,0.3)ceramics with increased tolerance factors were successfully *** amplitude of oxygen octahedral tilt mode indeed decreases with increasing tolerance factors,leading to a degeneration of ferroelectric ***,the unexpected rigid rotation mode causes the composition-invariable coercive *** Curie temperatures decrease linearly with increasing x and tolerance *** variable-temperature dielectric constant confirms first-order improper ferroelectric transitions in Ca_(3)Ti_(2)O_(7)-based *** results of variable temperature Xray diffraction reveal the coexistence of two-phases below Curie *** present work confidently confirms the first-order improper ferroelectric transition in Ca_(3)Ti_(2)O_(7)-based ceramics by combining results of variable-temperature dielectric response and in-situ X-ray powder diffraction.

关键词： Hybrid improper ferroelectricity Ca_(3)Ti_(2)O_(7) Rigid rotation mode First-order phase transition Dielectric response

3D Printing of Tough Hydrogel Scaffolds with Functional Surface Structures for Tissue Regeneration

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Nano-Micro Letters 2025年第2期17卷 18-45页

作者： Ke Yao Gaoying Hong Ximin Yuan weicheng Kong Pengcheng Xia Yuanrong Li Yuewei Chen Nian Liu Jing He Jue Shi zihe hu Yanyan zhou zhijian Xie Yong He State Key Laboratory of Fluid Power and Mechatronic Systems School of Mechanical EngineeringZhejiang UniversityHangzhou 310027People’s Republic of China Liangzhu Laboratory Zhejiang UniversityHangzhou 310027People’s Republic of China Key Laboratory of 3D Printing Process and Equipment of zhejiang Province College of Mechanical EngineeringZhejiang UniversityHangzhou 310027People’s Republic of China Stomatology Hospital School of StomatologyZhejiang University School of MedicineHangzhou 310027People’s Republic of China State Key Laboratory of Advanced welding and Joining Harbin Institute of TechnologyHarbin 150001People’s Republic of China Institute of Digital Medicine Nanjing First HospitalNanjing Medical UniversityNanjing 210006People’s Republic of China

Hydrogel scaffolds have numerous potential applications in the tissue engineering ***,tough hydrogel scaffolds implanted in vivo are seldom reported because it is difficult to balance biocompatibility and high mechanical *** by Chinese ramen,we propose a universal fabricating method(printing-P,training-T,cross-linking-C,PTC&PCT)for tough hydrogel scaffolds to fill this ***,3D printing fabricates a hydrogel scaffold with desired structures(P).Then,the scaffold could have extraordinarily high mechanical properties and functional surface structure by cycle mechanical training with salting-out assistance(T).Finally,the training results are fixed by photo-cross-linking processing(C).The tough gelatin hydrogel scaffolds exhibit excellent tensile strength of 6.66 MPa(622-fold untreated)and have excellent ***,this scaffold possesses functional surface structures from nanometer to micron to millimeter,which can efficiently induce directional cell ***,this strategy can produce bionic human tissue with mechanical properties of 10 kPa-10 MPa by changing the type of salt,and many hydrogels,such as gelatin and silk,could be improved with PTC or PCT *** experiments show that this scaffold can effectively promote the new generation of muscle fibers,blood vessels,and nerves within 4 weeks,prompting the rapid regeneration of large-volume muscle loss injuries.

关键词： 3D printing Tough hydrogel scaffold Functional surface structure Tissue regeneration Biomaterials

ATOMIzATION CAUSED BY BOTTOM FLOw ENERGY DISSIPATION

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Journal of Hydrodynamics 2001年第1期13卷 23-27页

作者： hu, M.L. Liang, z.C. zeng, Y.H. wuhan Univ. of Hydraulic and Electr. Wuhan 430072 China

Bottom flow energy dissipation is one of the common energy dissipation methods for flood-releasing structures with high water head. Measures of this energy dissipation depend mainly on the turbulent action of hydraulic jump. In this paper, the physical process and the calculating methods of the atomization caused by bottom flow energy dissipation were studied, the computation models of atomization quantity for the self-aerated flow in overflow and hydraulic jump regions are presented, and the main results are of theoretical and practical significance for the hydraulic and electric engineering.

关键词： Energy dissipation Hydraulic jump Hydrodynamics