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MICROSTRUCTURE ANALySIS AND MECHANICAL PROPERTIES OF Zn-Al ALLOy ROD PRODUCED By HEATED MOLD CONTINUOUS CASTING

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Acta Metallurgica Sinica(English Letters) 2003年第3期16卷 241-248页

作者： y.Ma y.Hao F.y.yan H.J.Liu State Key Laboratory of Advanced Nonferrous Materials Lanzhou University of Science & Technology Lanzhou 730050 ChinaState Key Laboratory of Advanced Nonferrous Materials Lanzhou University of Science & Technology Lanzhou 730050 ChinaState Key Laboratory of Advanced Nonferrous Materials Lanzhou University of Science & Technology Lanzhou 730050 ChinaSchool of Mechano-Electronic EngineeringHua Qian University Quanzhou 362011China

The new technology of continuous casting by heated mold was used to produce directional solidification ZA alloy lines to eliminate the inter defects of these lines and increase their mechanical properties. The results are as follows: (1) The microstruc-ture of the ZA alloy lines is the parallel directional dendritic columnar crystal. Every dendritic crystal of eutectic alloy ZA5 was composed of many layer eutectic β and η phases. The micro structure of hypereutectic ZA alloys is primary dendritic crystal and interdendritic eutectic structure. The primary phase of ZA8 and ZA12 is β, among them, but the primary phase of ZA22 and ZA27 is a. (2) Through the test to the as-cast ZA alloy lines made in continuous casting by heated mold, it is found that the tensile strength and hardness increase greatly, but the elongation decreases. With the increase of aluminum amount from ZA 5 to ZA 12, ZA22 and ZA27, the tensile strength increases gradually. ZA27 has the best comprehensive mechanical properties in these four kinds of ZA alloys. (3) Heat treatment can decrease the dendritic segregation and improve the elongation of ZA alloy, but make their strength decrease slightly.

关键词： zinc-aluminum alloy heated mold continuous casting mechanical properties heat treatment

Giant magnetocaloric effect in Tb_5Ge_(2-x)Si_(2-x)Mn_(2x) compounds

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Chinese Physics B 2010年第5期19卷 542-548页

作者： E.yzak B.Emre y.Elerman A.ycel Department of Engineering Physics Faculty of EngineeringAnkara University06100 BesevlerAnkaraTurkey Faculty of Science and Letters Physics DepartmentMugla UniversityKtekli 48000 MuglaTurkey

The crystal structure, magnetic and magnetocaloric characteristics of the pseduo ternary compounds of TbsGe2-xSi2-xMn2x （0 ≤ 2x ≤ 0.1） were investigated by x-ray powder diffraction and magnetization measurements. The x-ray powder diffraction results show that all compounds preserve the monoclinic phase as the majority phase and all the synthesized compounds were observed to be ferromagnetic from magnetization measurements. Magnetic phase transitions were interpreted in terms of Landau theory. Maximum isothermal magnetic entropy change value （20.84 J-kg-1 -K-1） was found for Tb5Ge1.95Si1.95Mn0.1 at around 123 K in the magnetic field change of 5T.

关键词： magnetic properties magnetocaloric effect isothermal magnetic entropy change

Bouncing scenario of general relativistic hydrodynamics in extended gravity

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Communications in Theoretical Physics 2021年第2期73卷 96-101页

作者： A y Shaikh B Mishra Department of Mathematics Indira Gandhi MahavidyalayaRalgaon-445402India Department of Mathematics Birla Institute of Technology and Science PilaniHyderabad CampusHyderabud-500078India

In this paper,we have framed bouncing cosmological model of the Universe in the presence of general relativistic hydrodynamics in an extended theory of *** metric assumed here is the flat Friedmann–Robertson–Walker space–time and the stress energy tensor is of perfect *** general relativity(GR)has certain issues with late time cosmic speed up phenomena,here we have introduced an additional matter geometry coupling that described the extended gravity to *** dynamical parameters are derived and *** dynamical behavior of the equation of state parameter has been *** have observed that the bouncing behavior is mostly controlled by the coupling parameter.

关键词： FRW metric extended gravity bouncing scenario energy conditions

AN HREM STUDy OF A LATERAL MICROCRACK BENEATHINDENTATION OF [001] SILICON

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Acta Metallurgica Sinica(English Letters) 1998年第5期11卷 342-346页

作者： y.Q.Wu X.y.yang y.B.Xu Inst of Metal Research The Chinese Acad of Sciences Shenyang China

A cross-sectional sample of indentation in [001] silicon was made and a lateral microcrack beneath the indentation was observed by high resolution electron microscope (HREM). The HREM images around the microcrack tip show an alternate distribution of the amorphous and lattice structure. The crack does not propagate by the successive debonding between certain atomic planes, meaning that before a crack completely opens, there may be a stage of amorphization, resulting from severe distortion of lattice.

关键词： amorphization lateal crack indentation HREM silicon

Equivariant PT-symmetric real Chern insulators

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Frontiers of physics 2020年第1期15卷 63-69,F0004页

作者： y.X.zhao National laboratory of solid state microstructures and department of physics nanjing universitynanjing 210093china Collaborative innovation center of advanced microstructures nanjing universitynanjing 210093china

It was understood that Chern insulators cannot be realized in the presence of PT *** this paper,we reveal a new class of PT-symmetric Chern insulators,which has internal degrees of freedom forming real representations of a symmetry group with a complex endomorphism *** a generalization to the conventional 2n-dimensional Chern insulators with integer n≥1,these PT-symmetric Chern insulators have the n-th complex Chern number as their topological invariant,and have a Z classification given by the equivariant orthogonal K ***,in a fairly different sense,there exist ubiquitously Chern insulators with *** generalizing the Thouless charge pump argument,we find that,for a PT-symmetric Chern insulator with Chern number *** are equally many v flavors of coexisting left-and right-handed chiral *** modes with opposite chirality are complex conjugates to each other as complex representations of the internal symmetry group,but are not *** the physical dimensionality d=2,the PT-symmetric Chern insulators may be realized in artificial systems including photonic crystals and periodic mechanical systems.

关键词： topological insulator Chern insulator

Ecological toxicity of reactive X-3B red dye and cadmium acting on wheat (Triticum aestivum)

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Journal of Environmental Sciences 2002年第1期14卷 136-140页

作者： Chen.y ZhouQX OpenLaboratoryofTerrestrialEcologicalProcess InstituteofAppliedEcologyChineseAcademyofSciencesShenyang110016China.E－mail：zhouq@*** OpenLaboratoryofTerrestrialEcologicalProcess Instituteof

Ecological toxicity of reactive X\|3B red dye and cadmium in both their single form and their combined form on wheat was studied using the experimental method of seed and root exposure. The single factor exposure indicated that the inhibitory rate of wheat root elongation was significantly increased with the increase in the concentration of the dye in the cultural solution, although seed germination of wheat was not sensitive to the dye. The toxicity of cadmium was greatly higher than that of the dye, but low concentration cadmium (ye and cadmium on wheat were complicated. There was no significant correlation between the inhibitory rate of seed germination and the concentrations of the dye and cadmium. Low concentration cadmium could strengthen the toxicity of the dye acting on root elongation. On the contrary, high concentration cadmium could weaken the toxicity of the dye acting on root elongation.

关键词： ecological toxicity reactive X 3B red dye cadmium combined pollution wheat

Effect of Strain Rate on Hydrogen Embrittlement Behaviour of Amorphous NiCrFeSiB Alloy

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Journal of Materials Science & Technology 1996年第2期12卷 105-108页

作者： Zuo, y Latanision, RM MIT CAMBRIDGEMA 02139

The effect of strain rate on hydrogen embrittlement behaviour of amorphous Ni-6.6Cr-2.6Fe-7.8Si-14.5B (at pct) alloy in 0.1 mol/L H2SO4 solution was studied by the methods of slow strain rate test and electrochemical charging. The results show that fracture stress of the alloy decreases with the decrease of strain rate within a certain range. As a tentative explanation, the effect of strain rate on hydrogen embrittlement fracture stress was attributed to the interaction between hydrogen and the excess volume in amorphous alloys.

关键词： Amorphous alloys

Effect of Aging Treatment on Microstructural and Mechanical Characteristics of PEO Coatings on Mg-Al Alloy

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Journal of Materials Science & Technology 2008年第1期24卷 37-40页

作者： y.L.Kim Department of Materials Engineering Korea Aerospace University Gyeonggi-do412-791Korea

Cast Mg-6 wt pct Al alloy solution-treated at 683 K for 16 h and aged at 498 K was coated by plasma electrolytic oxidation （PEO） *** Mg-6 wt pct Al alloy aged for 16 h exhibited the highest microhardness and wear *** PEO coating,however,the microhardness and wear resistance of coatings on Mg- 6 wt pct Al alloy showed a tendency to decrease with increasing aging time,which was in aggrement with the change of thickness with aging *** addition,the coatings on solution-treated Mg-6 wt pct Al alloy had better microhardness and wear resistance than those on aged Mg-6 wt pct Al ***,it can be understood that the aging treatment has a deleterious influence on the mechanical properties of coatings on Mg-6 wt pct Al alloy.

关键词： Cast Mg-6 wt pct Al Aging treatment Plasma electrolytic oxidation Thickness Microhardness Wear resistance

New Naturally Occurring Product Extract as Corrosion Inhibitor for 316 Stainless Steel in 5% HCl

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Journal of Materials Science & Technology 2004年第4期20卷 463-466页

作者： T.y.Soror Chemistry Department Faculty of Science Cairo University Cairo Egypt

Medipolymorphol, a new sterol isolated from the whole plant of Medicago polymorpha Roxb was used as corrosion inhibitor for 316 stainless steel in 5% HCI at room temperature. Electrochemical techniques have been found to be reliable in evaluating corrosion characteristics of the system. Several techniques have been used including Tafel, linear polarization, potentiodynamic polarization, and open circuit potential (OCP) studies. The additives simultaneously deaccelerated the anodic process, intensified the cathodic process and provided a stable passive state, giving good inhibition efficiencies to stainless steel electrodes. In addition, adsorption isotherm have been fitted for the inhibitor under investigation.

关键词： Medipolymorpho] Plant extract Stainless steel HCl Corrosion inhibitor