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Theoretical design of new bridge-ring insensitive high energy compounds by selected normal Diels-Alder reactions between NH_(2)-substituted oxazoles and NO_(2)/NF_(2)/NHNO_(2)-substituted ethylenes/acetylenes

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Defence technology（防务技术） 2021年第5期17卷 1731-1739页

作者： Qiong Wu Qin-nan Hu Ming-quan Li Ze-wu Zhang Wei-hua Zhu Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology School of Materials Science and EngineeringNanjing Institute of Technology1 Hongjing RoadNanjing211167China Institute for Computation in Molecular and Materials Science and Department of Chemistry Nanjing University of Science and TechnologyNanjing210094China

In this work,NH_(2)-substituted oxazoles and NO_(2)/NF_(2)/NHNO_(2)-substituted ethylenes/acetylenes were designed and used as dienes and dienophiles,respectively,in order to develop new bridge-ring insensitive high energy compounds through the Diels-Alder reaction between *** reaction type,reaction feasibility and performance of reaction products were investigated in detail *** results showed that dienes most possibly react with dienophiles through the HOMO-diene controlled normal Diels-Alder reaction at relatively low energy *** could react with the designed dienes much more easily than other dienophiles,and was employed to further design 29 new bridge-ring energetic *** to high heat of formation,density and oxygen balance,all designed bridge-ring energetic compounds have outstanding detonation performance,16 of them have higher energy than HMX(1,3,5,7-tetranitro-1,3,5,7-tetrazocine)and 2 others even possess comparative energy with the representative of high energy compounds CL-20(2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane).The predicted average h50 value of these bridge-ring energetic compounds is 83 cm,showing their low impact *** NH2 groups could obviously impel the proceeding of Diels-Alder reactions,but would slightly decrease the energy and sensitivity *** all,the new designed bridge-ring compounds have both high energy and low sensitivity,and may be produced through Diels-Alder reactions at relatively low energy *** paper may be helpful for the theoretical design and experiment synthesis of new advanced insensitive high energy compounds.

关键词： Diels-Alder Energetic compounds Oxazole High energy Insensitive

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Enhanced Microwave Absorption Properties of Double-Layer Absorbers Based on Spherical NiO and Co_(0.2)Ni_(0.4)Zn_(0.4)Fe_2O_4 Ferrite Composites

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Acta Metallurgica Sinica(English Letters) 2018年第2期31卷 171-179页

作者： Pei-Jiang Liu Zheng-Jun Yao Vincent Ming Hong Ng Jin-Tang Zhou Zhi-Hong Yang Ling-Bing Kong College of Materials and Technology Nanjing University of Aeronautics and Astronautics Nanjing 211100 China Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology Nanjing 211100 China School of Materials Science and Engineering Nanyang Technological University 50 Nanyang Avenue Singapore 639798 Singapore

Microwave absorption properties of spherical NiO particles and Co0.2Ni0.4Zn0.4Fe2O4（CNZF） ferrites with single-layer and double-layer absorbers were studied in the frequency range of 2–18 GHz. The spherical NiO particles were synthesized by using a hydrothermal process, while the CNZF powders were prepared by using a sol–gel autoignition method. The double-layer absorbers, composed of 30 wt% NiO as matching layer and 30 wt% CNZF as absorption layer,with a total thickness of 3.2 mm, exhibited a maximum reflection loss（RL） of –67.0 d B at 9.2 GHz and an effective absorbing bandwidth below –10 d B to be 3.9 GHz from 7.0 to 10.9 GHz. The excellent microwave absorption performance of the double-layer absorbers should be ascribed to the high impedance matching ratio, the great microwave attenuation capability, and well-coupled layer.

关键词： Hierarchical NiO particle Ferrite Impedance matching Microwave absorption property

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Effect of Solution Treatment on Microstructure and Corrosion Properties of Mg–4Gd–1Y–1Zn–0.5Ca–1Zr Alloy

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Acta Metallurgica Sinica(English Letters) 2018年第8期31卷 865-872页

作者： Jian-Wei Dai Xiao-Bo Zhang Yang Fei Zhang-Zhong Wang Huai-Ming Sui School of Materials Science and Engineering Nanjing Institute of TechnologyNanjing 211167China Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology Nanjing 211167China Yangzhou Fengming Optronic New Material Co. LtdYangzhou 225117China

The as-cast multi-element Mg–4Gd–1Y–1Zn–0.5Ca–1Zr alloy with low rare earth additions was prepared, and the solution treatment was applied at different temperatures. The microstructural evolution of the alloy was characterized by optical microscopy and scanning electron microscopy, and corrosion properties of the alloy in 3.5% NaCl solution were evaluated by immersion and electrochemical tests. The results indicate that the as-cast alloy is composed of the a-Mg matrix,lamellar long-period stacking-ordered（LPSO） structure and eutectic phase. The LPSO structure exists with more volume fraction in the alloy solution-treated at 440 °C, but disappears with the increase in the solution temperature. For all the solution-treated alloys, the precipitated phases are detected. The corrosion rates of the alloys decrease first and then increase slightly with the increase in the solution temperature, and the corrosion resistance of the solution-treated alloys is more than four times as good as that of the as-cast alloy. In addition, the alloy solution-treated at 480 °C for 6 h shows the best corrosion property.

关键词： Magnesium alloy Solution treatment Microstructure Corrosion properties

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Genetic Function Approximation Based QSPR Models for Predicting the Wetting Ability of Lubricants onto Rolled Copper Foil Surface

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China Petroleum Processing & Petrochemical technology 2018年第2期20卷 79-89页

作者： Xiong Sang Sun Jianlin College of Materials Engineering Nanjing Institute of TechnologyNanjing 211167 Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology Nanjing 211167 School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083

The contact angle phenomena and wetting behavior of fatty acids,alcohols and ester used as additives in lubricants onto the rolled copper foil(RCF)surface were studied by the static sessile drop ***-empirical quantum-chemical method studies on the contact angle of these compounds onto surface using several structural parameters were carried *** refractivity as well as several structural parameters were adopted in the development of quantitative structure-property relationships(QSPR)using genetic function approximation(GFA)statistical analysis *** results show that quantum parameters are a better choice when predicting the contact angle and wettability of lubricants onto the RCF *** angle of the compounds serves as a function of their viscosity,interfacial tension,and physicochemical *** P,molecular refractivity,molecular flexibility,total molecular mass,solvent surface area,element count,total energy and dipole are the most sensitive ones among the major contributing ***,studies of lubricants on the RCF surfaces allow wetting theories to be tested down to the microcosmic scale,which can bring about new insight to predict wettability of lubricants onto RCF surface.

关键词： lubricants wetting contact angle modelling QSPR

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Effect of Attapulgite Added in Plating Bath on the Properties of Ni/TiC Nano-composite Coatings

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Journal of Wuhan University of technology(materials Science) 2017年第2期32卷 250-255页

作者：王红星 MAO Xiangyang Key Laboratory of Advanced Structural Materials and Application Technolgoy of diangsu Province Nanjing 211167China School of Materials Engineering Nanjing Institute of TechnologyNanjing 211167China

Pure copper plates were coated by Ni-TiC dipulse current plating method. The effects of adding different concentration（ranging from 0.5 g/L to 3.0 g/L） of attapulgite nano particles to the plating bath on the surface morphology, wear resistance, and oxidation resistance of Ni/TiC/Attapulgite nano-composite coatings were investigated. The experimental results show that the composite coating is flat and compact with adding 3.0 g/L in the bath, and the coating preferred orientation is changed from the planes（111） to（200）. The coefficient of the composite coatings decreases from 0.68 to 0.18 with increasing content of attapulgite in the bath, a mixed mode of adhesive-abrasive wear occurs for all coatings, and the wear mechanism shows a transition from adhesive-abrasive to predominantly abrasive wear mechanism when the concentration of attapulgite is beyond 1.5 g/L in electrolyte. The oxidation resistance of composite coatings is the best prepared when adding attapulgite particles at 0.5 g/L in the bath, the oxide mainly consists of a NiO phase by X-ray analysis.

关键词： Ni-TiC composite coating dipulse electrodeposition attapulgite wear resistance oxidation resistance

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Effect of rolling temperature on microstructure and texture of twin roll cast ZK60 magnesium alloy

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Transactions of Nonferrous Metals Society of China 2010年第11期20卷 2086-2091页

作者：陈洪美于化顺 Suk-bong KANG 闵光辉金云学 Provincial Key Lab of Advanced Welding Technology Jiangsu University of Science and Technology Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials Ministry of Education Shandong University Korea Institute of Materials Science

Twin roll cast ZK60 alloy strip/sheet with final thickness of 0.5 mm was prepared, and effect of rolling temperature on microstructure and texture development was investigated using OM and XRD technique, microstructure and texture were measured on specimens subjected to rolling experiment at different rolling temperature, and macrotexture was also evaluated by X-ray diffraction method. In addition, the （1010）and （0002） pole figures were measured, and the tensile test was performed to reveal the influence of rolling temperature on mechanical properties. The results show that the microstrucmre of ZK60 alloy sheet consisted of fibrous structure with elongated grains, and shear bands along the rolling direction after warm rolling. Dynamic recrystallization could be found during the warm rolling process at rolling temperature 350℃ and above. And many fine recrystallized grain could be observed in the shear bands area. It is a little difficult to see the recrystallized grain in the sheet warm rolled at 300℃ because of higher density of shear bands. The warm rolled ZK60 alloy sheet exhibited strong （0002） pole texture, the intensity of （0002） pole figure decreases with the increasing of rolling temperature and the basal pole tilted slightly to the transverse direction after warm rolling.

关键词： warm rolling microstructure macrotexture pole figure ZK60 alloy

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Detwinning and Anneal-Hardening Behaviors of Pre-Twinned AZ31 Alloys under Cryogenic Loading

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Acta Metallurgica Sinica(English Letters) 2024年第9期37卷 1551-1563页

作者： Lingyu Zhao Wei Zhu Chao Zhang Yunchang Xin Changjian Yan Yao Cheng Zhaoyang Jin School of Mechanical Engineering Yangzhou UniversityYangzhou225127China Key Laboratory for Light-Weight Materials Nanjing Tech UniversityNanjing210009China Institute of Corrosion Science and Technology Guangzhou510070GuangdongChina Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology Nanjing Institute of TechnologyNanjing211167China

Detwinning behavior of a pre-twinned magnesium alloy AZ31 at cryogenic temperature was investigated,also with a focus on the annealing hardening behavior of samples with different fractions of ***-compression along the transverse direction with strains of 1.7%,3.0%,and 6.0% was applied to generated[1012]*** behavior,microstructure,and texture evolution during subsequent tension were *** results show that low temperature did not change the fact that detwinning still pre-dominated in the pre-twinned samples under reverse ***,a relatively harder migration of twin boundaries was found at cryogenic *** annealing hardening of 27-40 MPa was observed in the pre-twinned samples,and such a hardening effect shows a close relation with the fraction of pre-twins or the level of *** annealing hardening effect disappeared if the matrix was consumed by twins along with the increased pre-compression *** corresponding reasons for the annealing hardening behavior were discussed.

关键词： Mg alloys Detwinning Annealing hardening Cryogenic temperature Mechanical property

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Accurate prediction method for the microstructure of amorphous alloys without non-metallic elements

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Chinese Physics B 2021年第11期30卷 440-444页

作者： Wei Zhao Jia-Lin Cheng Gong Li Xin Wang School of Materials Science and Engineering Nanjing Institute of TechnologyNanjing 211167China State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology Nanjing 211167China School of Materials Science and Engineering Harbin University of Science and TechnologyHarbin 150080China

A new structural parameter of amorphous alloys called atomic bond proportion was proposed, and a topological algorithm for the structural parameter was proven feasible in the previous work. In the present study, a correction factor, λ,is introduced to optimize the algorithm and dramatically improve the calculation accuracy of the atomic bond *** correction factor represents the ability of heterogeneous atoms to combine with one another to form the metallic bonds and it is associated with the uniformity of the master alloy, mixing enthalpy, cooling rate during preparation, and annealing time. The correction factor provides a novel pathway for researching the structures of the amorphous alloys.

关键词： atomic bond proportion correction factor amorphous materials microstructure

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Microstructure evolution of extruded Mg-RE-Ag alloy during short-time heat treatment

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Journal of Rare Earths 2024年第12期42卷 2350-2361,I0006页

作者： Zehua Li Jinghuai Zhang Shujuan Liu Jiaming Hao Liyuan Liu Yuying He Haodong Zhang Xingkai Jiao Xiaobo Zhang Ruizhi Wu Key Laboratory of Superlight Material and Surface Technology Ministry of EducationCollege of Material Science and Chemical EngineeringHarbin Engineering UniversityHarbin150001China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin150001China Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology Nanjing Institute of TechnologyNanjing211167China

Microstructure regulation via short-time heat treatment is conducive to the optimization in the microstructure and properties of precipitable magnesium(Mg)alloys,but there is currently a lack of relevant *** this work,the microstructure evolution of a Mg-RE-Ag alloy during different short-time heat treatments was characterized and *** results show that extreme short-time heat treatment(ESHT,e.g.,2 min)at 450-480℃can greatly increase solute concentration in Mg matrix through the rapid re-dissolution of the second-phase and simultaneously maintain fine grains,while the ESHT at a too high temperature(e.g.,510℃)is not suitable due to excessive grain growth and coarse second phase regenerated at grain *** is found that 480℃is the approximate critical temperature for appropriate ESHT,and further prolongation of the time will lead to excessive grain *** is suggested that in addition to grain boundary migration,grain rotation is activated,resulting in the annihilation of high-angle grain boundaries with relatively low misorientation,as well as the reduction in the ability of the residual second phase to pin grain *** addition,the reasons for the abnormal grain boundary segregation and grain boundary continuous phase were analyzed from the perspective of interfacial *** study provides a basis for effective microstructure regulation of Mg-RE alloys.

关键词： Magnesium alloy Rare earths Microstructure Heat treatment Precipitates

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Corrosion mechanism of Mg alloys involving elongated long-period stacking ordered phase and intragranular lamellar structure

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Journal of materials Science & technology 2023年第20期151卷 190-203页

作者： Jinshu Xie Jinghuai Zhang Zhi Zhang Zijian Yu Zhihao Xu Ru Wang Daqing Fang Xiaobo Zhang Xiaoru Zhang Ruizhi Wu Key Laboratory of Superlight Material and Surface Technology Ministry of EducationCollege of Materials Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150001China Faculty of Materials and Manufacturing Beijing University of TechnologyBeijing 100124China State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an 710049China Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology Nanjing Institute of TechnologyNanjing 211167China

It is a long-term challenge to further improve the corrosion resistance while ensuring the strength of magnesium(Mg)*** the effect of potential fluctuation on the micro-galvanic corrosion and the subsequent film formation is important for understanding the corrosion mechanism of Mg alloys with multiple strengthening phases/***,we prepared the high-strength Mg-14.4Er-1.44Zn-0.3Zr(wt.%)alloys containing hybrid structures,i.e.,elongated long-period stacking ordered(LPSO)blocks+intragranular stacking faults(SFs)/LPSO *** Mg alloy with elongated LPSO blocks and intragranular LPSO lamellae(EZ-500 alloy)obtains good corrosion resistance(2.2 mm y^(–1)),while the Mg alloy containing elongated LPSO blocks and intragranular SFs(EZ-400 alloy)shows a significantly higher corrosion rate(6.9 mm y^(–1)).The results of scanning Kelvin probe force microscopy(SKPFM)show the elongated LPSO blocks act as cathode phase(87 mV in EZ-400 alloy),and the SFs serve as the weak anode(30 mV in EZ-400 alloy),resulting in high potential fluctuation in EZ-400 *** the contrary,both elongated blocks and intragranular lamellae are cathodic LPSO phase(67–69 mV)in EZ-500 alloy,leading to a lower potential *** in-situ atomic force microscope(AFM)observation indicates that high potential fluctuation would cause strong micro-galvanic corrosion,and subsequently leads to the failure in rapid formation of corrosion film,finally forming a loose and porous film,while relatively low potential fluctuation could result in more uniform corrosion mode and facilitate the rapid formation of protective ***,we propose that it is an effective way to develop high-strength corrosionresistant Mg alloys by controlling the potential fluctuation to form a“uniform potential”strengthening microstructure。

关键词： Mg alloys Stacking faults LPSO phase SKPFM Quasi in-situ AFM Corrosion behavior Potential fluctuation

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