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Modified spherical cavity-expansion model for projectile penetration into concrete targets

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Acta Mechanica Sinica 2019年第3期35卷 518-534页

作者： Y.Peng h.Wu q.Fang X.Z.Kong College of Liberal Arts and Sciences National University of Defense TechnologyChangsha 410073China Key Laboratory of Performance Evolution and Control for Engineering Structures Tongji UniversityShanghai 200092China research Institute of Structural Engineering and Disaster reduction College of Civil EngineeringTongji UniversityShanghai 200092China State Key Laboratory for Disaster Prevention and Mitigation of Explosion and Impact PLA Amy Engineering UniversityNanjing 210007China

A modified spherical cavity-expansion model is developed in this paper.(1) We introduce a piecewise hyperbolic yield criterion suitable for pressure less than fc/3 to describe the mechanical behavior in the elastic region for the elastic-plastic response and modify the crack occurrence condition for the elastic-cracked-plastic response.(2) The hyperbolic yield criterion and a piecewise equation of state (EOS) are adopted for a better description of the plastic behavior of concrete material. Then, the modified model is validated by several projectile penetration tests in both the normal strength concrete (NSC) and ultra-high performance cement-based composite (UhPCC) targets. Finally, the hydrostatic pressure of the targets under rigid ogive-nosed projectile penetrations is found to be nearly within (0, 1.6 GPa), which usually exceeds the range that the shear strength-pressure test data covered. The influence of yield criterion on depth of penetration is discussed and it is recommended that the pressure should arrive at least 400 MPa in the related triaxial compression tests.

关键词： Dynamic cavity-expansion model Projectile Penetration Concrete Depth of penetration

An in-vitro Investigation of Iron-Containing hydroxyapatite/Titanium Composites

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Journal of Materials Science & Technology 2011年第6期27卷 546-552页

作者： q. Chang h.q. ru D.L. Chen X.Y. Yue L. Yu C.P. Zhang Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education) Northeastern University Shenyang 110004 China Department of Mechanical and Industrial Engineering Ryerson University 350 Victoria Street Toronto Ontario M5B 2K3 Canada

The in-vitro biological behavior of a newly-developed iron-containing hydroxyapatite/titanium（hA/Ti） composite was investigated by immersing the composites in the simulated body fluid（SBF） for up to 5 *** addition of iron was observed to have a significant influence on the in-vitro biological behavior of the *** obtained results revealed that the stability of the composites in the physiological solution was markedly *** solubility decreased in the order of pure hA,hA/5（Ti-33Fe）,and hA/15（Ti33Fe）.Precipitation occurred on the surface of hA/5（Ti-33Fe） composite,showing a good combination of physiostability with bioactivity,while hA/15（Ti-33Fe） composite exhibited superior physiostability since there was no obvious change on the surface of hA/15（Ti-33Fe）.

关键词： hydroxyapatite composite Iron Titanium Simulated body fluid Biological behavior

Nitrogen Contents on Tribological Properties of Magnetron Sputtered SICN Coatings

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材料热处理学报 2004年第05B期25卷 854-857页

作者： TIETUNSUN Y.q.FU J.WEI h.J.DU Departmentofphysics ShanghaiJiaotongUniversityShanghaiChina／／SchoolofMechanicalandProductionEngineeringNanyangTechnologicalUniversitySingapore639798 SchoolofMechanicalandProductionEngineering NanyangTechnologicalUniversitySingapore639798／／SingaporeInstituteofManufacturingTechnologySingapore71NanyangDriveSingapore638075 SingaporeInstituteofManufacturingTechnology -Singapore71NanyangDrivesingapore638075

Silicon carbonitride (SiCN) coatings were deposited on silicon and tungsten carbide substrates by co-sputtering silicon and carbon in argon and nitrogen mixture atmosphere using magnetron-sputtering system. The effect of the N2 concentration, rF substrate bias voltage and target current on film deposition rate, roughness, adhesion, mechanical and tribological properties of coatings were investigated. The deposition rate was found to increase with the increasing nitrogen concentration. X-ray photoelectron spectroscopy analysis showed that high nitrogen concentration in the nitrogen-argon gas mixture enhanced the incorporation of C and N but reduced the incorporation of Si. SiCN coatings have good tribological properties at a N2 concentration of approximately 60%.

关键词： SiCN涂层磁控管溅射含氮量硬度磨损

Magnetic/Magnetostrictive Properties Together with resistivity and Corrosion Behaviors of CoFe_2 and Its Composite with CoFe_2N

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Journal of Materials Science & Technology 2017年第7期33卷 744-750页

作者： B.q.Geng Y.q.Ma M.Wang Z.L.Ding W.h.Song B.C.Zhao Key Laboratory of Materials Physics Institute of Solid State Physics Chinese Academy of Sciences Hefei 230031 China

The CoFe_2alloy（CF） was prepared by reducing CoFe_2O_4 in the h_2 ambient. Subsequently the CF sample was nitrided in the Nh_3 atmosphere to produce the composite of CoFe_2N and CoFe_2. The magnetostriction, thermal expansion, resistivity and corrosion resistance of CF sample and the nitrided sample（CFN）at 1000？C were investigated. The saturation magnetostriction coefficiency λ_s and thermal expansion coefficient ？ at 300 K for the nitrided CFN were 50 ppm and 10 ppm/K, respectively, approximately equal to those for the CF sample. however, compared with CF, CFN presents a decrease in temperature coefficient r_λ（300 K） of magnetostriction by 11%. The smaller resistivity and improved corrosion resistance in the h_2SO_4 solution may expand the applications of the CoFe_2 in the fields needing lower resistivity or in the acidic environment.

关键词： CoFe alloy CoFe_2N alloy Magnetostriction resistivity Corrosion resistance

Effects of chemical pressure on diluted magneticsemiconductor(Ba,K)(Zn,Mn)_2As_2

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Chinese Physics B 2019年第5期28卷 288-292页

作者： Y Peng S Yu G q Zhao W M Li J F Zhao L P Cao X C Wang q q Liu S J Zhang r Z Yu Z Deng X h Zhu C q Jin College of Materials Science & Engineering Sichuan University Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of Sciences School of Physics University of Chinese Academy of Sciences Collaborative Innovation Center of quantum Matter

Chemical pressure induced by iso-valent doping has been widely employed to tune physical properties of materials. In this work, we report effects of chemical pressure by substitution of Sb or P into As on a recently discovered diluted magnetic semiconductor(Ba,K)(Zn,Mn)_2 As_2, which has the record of reliable Curie temperature of 230 K due to independent charge and spin doping. Sb and P are substituted into As-site to produce negative and positive chemical pressures, respectively.X-ray diffraction results demonstrate the successful chemical solution of dopants. Magnetic properties of both K-underdoped and K-optimal-doped samples are effectively tuned by Sb-and P-doping. The hall effect measurements do not show decrease in carrier concentrations upon Sb-and P-doping. Impressively, magnetoresistance is significantly improved from7% to 27% by only 10% P-doping, successfully extending potential application of(Ba,K)(Zn,Mn)_2 As_2.

关键词： chemical pressure (Ba,K)(Zn,Mn)2As2 diluted magnetic semiconductor iso-valent doping

Microstructure evolution and shape memory behaviors of Ni_(47)Ti_(44)Nb_(9)alloy subjected to multistep thermomechanical loading with different prestrain levels

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Journal of Materials Science & Technology 2024年第4期171卷 80-93页

作者： Y.h.Zhang h.Li Z.W.Yang X.Liu q.F.Gu State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Shaanxi Key Laboratory of high-Performance Precision Forming Technology and Equipment Northwestern Polytechnical UniversityXi’an 710072China

Ni_(47)Ti_(44)Nb_(9)shape memory alloy(SMA)is a promising material in the aerospace field due to its wide transformation *** application of shape memory effect depends on multistep thermomechan-ical loading,viz.,low-temperature deformation and subsequent heating to ***-temperature deformation prestrain plays a pivotal role in shape memory properties tailoring of SMA ***,microstructure evolution and deformation mechanisms of Ni_(47)Ti_(44)Nb_(9)SMA subjected to vari-ous prestrain levels are still *** this end,microstructure evolution and shape memory behaviors of Ni_(47)Ti_(44)Nb_(9)alloy subjected to multistep thermomechanical loading with prestrain levels of 8%-16%at-28℃(M_(s)+30℃)were *** results demonstrate that the stress-strain curve of the specimen exhibits four distinct stages at a maximal prestrain of 16%.Whereas stageⅡand stageⅢend at prestrains of∼8%and∼12%,*** stageⅡ,the stress-induced martensitic transformation is accompanied by the dislocation slip of the NiTi matrix andβ-Nb *** stageⅢ,in addition to the higher density of dislocations and further growth of stress-induced martensite variants(SIMVs),(001)compound twins are introduced as a result of the(001)deformation twinning in stress-induced ***{20-1}martensite twins are gradually introduced in stageⅣ.Correspondingly,after subsequent unloading and heating,a higher density ofraustenite twins form in the specimen with a larger prestrain of 16%.With increasing prestrain from 8%to 16%,the recoverable strainε_(re)^(T)upon heating increases first and then ***ε_(re)^(T)obtains a maximum of 7.03%at 10%prestrain and de-creases to 6.17%at 16%*** increase ofε_(re)^(T)can be attributed to the formation of new SIMVs,the further growth of existing SIMVs,and the recoverable(001)compound *** the decrease ofε_(re)^(T)is mainly associated with the irrecoverable strain by{20−1}martensite *** effe

关键词： Ni_(47)Ti_(44)Nb_(9)shape memory alloy Wide transformation hysteresis Thermomechanical loading Microstructure evolution Shape memory behaviors Stress-induced martensitic transformation Deformation twinning

Stochastic Accelerated Alternating Direction Method of Multipliers for hedging Communication Noise in Combined heat and Power Dispatch

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CSEE Journal of Power and Energy Systems 2023年第2期9卷 696-706页

作者： Zhigang Li Xinyu Liang Fan hu Wen Xiong renbo Wu J.h.Zheng q.h.Wu School of Electric Power Engineering South China University of TechnologyGuangzhou 510641China Guangzhou Power Supply Bureau Guangdong Power Grid Co.LtdGuangzhouChina

Combined heat and power dispatch(ChPD)opens a new window for increasing operational flexibility and reducing wind power *** power and district heating systems are independently controlled by different system operators;therefore,a decentralized solution paradigm is necessary for ChPD,in which only minor boundary information is required to be exchanged via a communication ***,a nonideal communication environment with noise could lead to divergence or incorrect solutions of decentralized *** bridge this gap,this paper proposes a stochastic accelerated alternating direction method of multipliers(SA-ADMM)for hedging communication noise in *** algorithm provides a general framework to address more types of constraint sets and separable objective functions than the existing stochastic *** from the single noise sources considered in the existing stochastic approximation methods,communication noise from multiple sources is addressed in both the local calculation and the variable update *** studies of two test systems validate the effectiveness and robustness of the proposed SAADMM.

关键词： Alternating direction method of multipliers combined heat and power dispatch communication noise decentralized optimization

Ab-initio calculations of bandgap tuning of In1-xGaxY(Y=N,P)alloys for optoelectronic applications

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Chinese Physics B 2021年第11期30卷 467-474页

作者： Muhammad rashid Jamil M Mahmood q Shahid M ramay Asif Mahmood A Ghaithan h M Department of Physics Ghazi University City CampusDera Ghazi Khan32200Pakistan Department of Physics COMSATS University IslamabadIslamabad 44000Pakistan Basic and Applied Scientific research Center(BASrC) College of Science of DammamImam Abdulrahman Bin Faisal UniversityP.O.Box 383Dammam 31113Saudi Arabia Department Physics College of ScienceImam Abdulrahman Bin Faisal UniversityP.O.Box 1982Dammam 31441Saudi Arabia Physics and Astronomy Department College of ScienceKing Saud UniversityRiyadhSaudi Arabia Chemical Engineering Department College of EngineeringKing Saud UniversityRiyadhSaudi Arabia

The III–V alloys and doping to tune the bandgap for solar cells and other optoelectronic devices has remained a hot topic of research for the last few *** the present article,the bandgap tuning and its influence on optical properties of In1-xGaxN/P,where(x=0.0,0.25,0.50,0.75,and 1.0)alloys are comprehensively analyzed by density functional theory based on full-potential linearized augmented plane wave method(FP-LAPW)and modified Becke and Johnson potentials(TB-mBJ).The direct bandgaps turn from 0.7 eV to 3.44 eV,and 1.41 eV to 2.32 eV for In1-xGaxN/P alloys,which increases their potentials for optoelectronic *** optical properties are discussed such as dielectric constants,refraction,absorption,optical conductivity,and *** light is polarized in the low energy region with minimum *** absorption and optical conduction are maxima in the visible region,and they are shifted into the ultraviolet region by Ga ***,static dielectric constant e1(0)is in line with the bandgap from Penn’s model.

关键词： density functional theory direct bandgap III-V semiconductors tuning of optical band gap solar cell applications

ELECTrOChEMICAL NOISE ANALYSIS OF ThE INFLUENCE OF ThE Zn^(2+)IONS CONCENTrATION ON ZINC ELECTrOPLATING

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Acta Metallurgica Sinica(English Letters) 2005年第2期18卷 137-144页

作者： Z.Zhang C.S.Wu q.Y.Cai F.h.Cao J.q.Zhang DepartmentofChemistry ZhejiangUniversityHangzhou310027China DepartmentofChemistry ZhejiangUniversityHangzhou310027China／／StateKeyLaboratoryforCorrosionandProtectionInstituteofMetalResearchTheChineseAcademyofSciencesShenyang110016China

The influence of the concentration of Zn2+ ions on zinc electroplating process was investigated by means of electrochemical noise (EN) and cyclic voltammetry methods in conjunction with the scanning electron microscopy (SEM) technique. It was found that the EN generated during the electroplating of dentritic or large polymeric zinc deposit has large potential oscillation amplitude and positive potential drift while the compact zinc deposit possesses small noise amplitude and little potential drift. With the change of rate determining step from diffusion-control through mixed-control to activation-control, the maximum relative energy obtained from wavelet analysis defined from the region with larger scales to those with smaller scales, and the EDP (relative energy distribution plot) can be us, as 'fingerprints' of EN to characterize the electroplating process and the deposit structure. The results also showed that electrochemical noise technique can give more information about the electrodeposit structure than other normal electrochemical measurements, such as linear potential sweep method and cyclic voltammetry technique.

关键词： zinc electroplating zinc ions concentration electrochemical noise electrodeposit structure