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Correlation between crystal structure and mechanical performance of Cr-implanted 300M high-strength steel using X-ray diffraction method

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Journal of Iron and Steel Research International 2019年第10期26卷 1106-1116页

作者： Xiao-hu Chen Ping-ze Zhang Dong-bo Wei Xiao Huang feng Ding feng-kun li Xian-jun Dai Zhang-zhong Wang College of Materials Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211106JiangsuChina Ningbo Branch China Ordnance AcademyNingbo 315103ZhejiangChina Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology Nanjing 211167JiangsuChina Key Laboratory of Materials Preparation and Protection for Harsh Environment(Nanjing University of Aeronautics and Astronautics) Ministry of Industry and Information TechnologyNanjing 211106JiangsuChina Department of Mechanical and Aerospace Engineering Carleton UniversityOttawaON ONK1S5B6Canada

In order to study the influence of crystal structure change due to implantation dose on the hardness and wear performance of 300M high-strength steel,samples were surface modified by Cr implantation with dosages of 5.0 × 10^16,1.5 × 10^17 and 3.0 × 10^17 ions/cm^2.X-ray diffraction method,which was already applied in studies on the microstructure of deformed and heat-treated materials,was used to study the crystal structure of the implanted steel,and the results were corrected with the hardness and wear *** solid solution strengthening effect and microstructure vary with increase in implantation *** to strong solid solution hardening of Cr,small average crystallite size and high dislocation density,the hardness and wear resistance of implanted steel with dose of 5.0 × 10^16 ions/cm^2 were found to be the highest compared with other ***,although the crystal lite size of the implanted sample with dose of 3 × 10^17 ions/cm^2 was similar to that of substrate and the dislocation density was lower than that of the substrate,its higher hardness and lower specific wear rate were due to the solid solution hardening and perhaps Cr clusters reinforcement.

关键词： X-ray diffraction method Ion implantation Dislocation density Hardness Wear Crystal structure

High-temperature stability of retained austenite and plastic deformation mechanism of ultra-fine bainitic steel isothermally treated below Ms

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Journal of Iron and Steel Research International 2024年第8期31卷 2014-2030页

作者： Ting-ting He feng Hu kun Wang Wen Zhou li li Serhii Yershov Kai-ming Wu The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Collaborative Innovation Center for Advanced Steels Wuhan University of Science and TechnologyWuhan 430081HubeiChina Zhejiang Tsingshan Iron and Steel Co. Ltd.Qingtian 323903ZhejiangChina

The mechanical properties of the sample and the stability of retained austenite were studied by designing two kinds of ultra-fine bainitic steel with different heat treatment methods austempering above and below Ms(martensite start tem-perature),which were subjected to tensile tests at 20 and 450℃,*** results show that compared to room temperature(20℃)tensile properties,the uniform elongation of the sample at high temperature(450℃)significantly ***,the uniform elongation of the sample austempered above Ms decreased from 8.0%to 3.5%,and the sample austempered below Ms decreased from 10.9%to 3.1%.Additionally,the tensile strength of the sample austempered above Ms significantly decreased(from 1281 to 912 MPa),and the sample austempered below Ms slightly decreased(from 1010 to 974 MPa).This was due to the high carbon content(1.60 wt.%),high mechanical stability,low thermal stability for the retained austenite of the sample austempered below ***,the retained austenite decomposed at high temper-atures,the carbon content and transformation driving force were significantly reduced,the transformation rate increased,and the phase transformation content reduced.

关键词： Ultra-fine bainite Isothermal treatment High-temperature tensile property Retained austenite stability Plastic deformation

Effect of microalloying on wettability and interface characteristics of Zr-based bulk metallic glasses with W substrate

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China Foundry 2024年第4期21卷 352-359页

作者： Zhen Zhang lin-na feng Jin-he Wang Zheng-kun li Hua-meng Fu Hong li Zheng-wang Zhu Hai-feng Zhang School of Materials Science and Engineering Shenyang University of TechnologyShenyang 110870China Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China School of Metallurgy Northeastern UniversityShenyang 110004China

The infiltration casting method is widely employed for the preparation of ex-situ composite ***,the production of composite materials using this method must necessitates a comprehensive understanding of the wettability and interface characteristics between the reinforcing phase and the bulk metallic glasses(BMGs).This work optimized the composition of Zr-based BMGs through microalloying methods,resulting in a new set of Zr-based BMGs with excellent glass-forming *** experiments between the Zr-based BMGs melts and W substrates were conducted using the traditional sessile drop method,and the interfaces were characterized utilizing a scanning electron microscope(SEM)equipped with energy dispersive X-ray spectroscopy(EDS).The work demonstrates that the microalloying method substantially enhances the wettability of the Zr-based BMGs ***,the incorporation of Nb element impedes the formation of W-Zr phases,but the introduction of Nb element does not alter the extent of interdiffusion between the constituent elements of the amorphous matrix and W element,indicating that the influence of Nb element on the diffusion of individual elements is minute.

关键词： Zr-based BMGs infiltration casting method wettability interface characteristics W-Zr phases

Effects of 1 MeV electron radiation on the AlGaN/GaN high electron mobility transistors

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Journal of Semiconductors 2024年第9期45卷 70-75页

作者： Shijie Pan Shiwei feng Xuan li Zixuan feng Xiaozhuang Lu kun Bai Yamin Zhang College of Microelectronics Beijing University of TechnologyBeijing 100124China Institute of Microelectronics Chinese Academy of SciencesBeijing 100029China

In this study, the effects of 1 MeV electron radiation on the D-mode GaN-based high electron mobility transistors(HEMTs) were investigated after different radiation doses. The changes in electrical properties of the device were obtained, and the related physical mechanisms were analyzed. It indicated that under the radiation dose of 5 × 10^(14) cm^(-2), the channel current cannot be completely pinched off even if the negative gate voltage was lower than the threshold voltage, and the gate leakage current increased significantly. The emission microscopy and scanning electron microscopy were used to determine the damage location. Besides, the radiation dose was adjusted ranging from 5 × 10^(12) to 1 × 10^(14) cm^(-2), and we noticed that the drain-source current increased and the threshold voltage presented slightly negative shift. By calculations, it suggested that the carrier density and electron mobility gradually increased. It provided a reference for the development of device radiation reinforcement technology.

关键词： AlGaN/GaN HEMT electron radiation performance degradation device damage

Atropisomerism of diastereomer diribonucleoside phosphotriester

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Chinese Chemical Letters 2013年第1期24卷 13-16页

作者： Lu-Xin Na Xu-lin Sun Meng Wang kun-feng li Lei Xing Zhuo Chen Zhu Guan Zhen-Jun Yang State Key Laboratory of Natural and Biomimetic Drugs School of Pharmaceutical Sciences Peking University

linear diribonucleoside phosphotriester is an important intermediate for synthesizing biologically important compounds, such as cyclic bis（3＇-5＇） diguanylic acid （c-di-GMP） and its analogues. Atropisomerism of diastereomers generated by the chiral center of the P atom, which results in the doubling of signals in 31p NMR. The data of 31p NMR at different temperature are presented, and thereafter the reason is discussed.

关键词： Diribonucleoside phosphotriesterAtropisomer31p NMR

Review on regulation of MnS in non-qquenched and tempered steel

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Journal of Iron and Steel Research International 2024年第4期31卷 779-789页

作者： Guo-xing Qiu Qing Du feng Lu De-jun Miao Yong-kun Yang Xiao-ming li School of Metallurgical Engineering Xi'an University of Architecture and TechnologyXi'an 710055ShaanxiChina Laigang Technique Center Shandong Iron and Steel Group Co.Ltd.Jinan 271104ShandongChina

An overview of the current research status and control methods of MnS in non-quenched and tempered steel was *** a low-melting plastic inclusion,the morphology and distribution of MnS were influenced by various production ***,control of MnS is a systematic problem that must be integrated into the entire production *** on the production process,the factors affecting the morphology and distribution of MnS in steel were *** effects of oxygen activity,manganese,sulfur,and some alloys on MnS inclusion precipitation were summarized,mainly including MnS modification treatment and oxygen-sulfide composite precipitation *** is believed that MnS precipitates during the solidification process of steel,and controlling the solidification cooling rate could effectively regulate the size and morphology of MnS,avoiding the precipitation of ***,by changing the deformation rate,deformation amount,deformation temperature during the hot deformation process,and heating time and temperature during heat treatment,the distribution and morphology of MnS could be *** the fine control of the above process parameters,the number of II-MnS in steel could be effectively reduced,and their morphology could be improved,thereby enhancing the performance of non-quenched and tempered steel and promoting its wider ***,applying laboratory research results to industrial production is an important direction for future research efforts in this field.

关键词： MnS Non-quenched and tempered steel Control technology Process parameter Morphology Distribution

Molecular Chain Flexibility and Dielectric Loss at High-Frequency:Impact of Ester Bond Arrangement in Poly(ester imide)s

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Chinese Journal of Polymer Science 2024年第8期42卷 1122-1133页

作者： Ya-Dong li Hong li Lu-kun feng feng Bao Ming-liang Wang Cai-Zhen Zhu Zhao-Hui Zheng Xiao-Bin Ding Jian Xu Chengdu Institute of Organic Chemistry Chinese Academy of SciencesChengdu 610041China University of Chinese Academy of Sciences Beijing 100081China Institute of Low-Dimensional Materials Genome Initiative College of Chemistry and Environmental EngineeringShenzhen UniversityShenzhen 518060China

The evolution of high-frequency communication has accentuated the significance of controlling dielectric properties in polymer ***,it has been theorized that rigid molecular chains lead to lower dielectric ***,the validity of this proposition at high frequencies remains *** scrutinize the correlation between chain flexibility and dielectric properties,we synthesized six poly(ester imide)s(PEIs)with systematically varied molecular chain flexibilities by modifying the ester's substitution on the aromatic *** introduction of ester bonds bestowed all PEI films with a low dielectric dissipation factor(D_(f)),ranging from 0.0021 to 0.0038 at 10 GHz in dry *** dry D_(f)displayed a pattern consistent with volume polarizability(P/V).Unexpectedly,PI-mmm-T,featu ring the most flexible molecular chain,exhibited the lowest dielectric loss under both dry(0.0021@10 GHz)and hygroscopic(0.0029@10 GHz)***,the observed increase in D_(f)after humidity absorption suggests that the high dielectric loss of PEI in applications may be attributed to its hygroscopic *** simulations and characterization of the aggregation structure revealed that the smaller cavities within flexible molecular chains,after close stacking,impede the entry of water *** sacrificing high-temperature resistance,the precursor exhibited enhanced solubility properties and could be processed into high-quality *** research unveils new insights into the relationship between flexibility and highfrequency dielectric loss,offering innovative perspectives on synthesizing aromatic polymers with exceptional dielectric properties.

关键词： 5G communications Poly(ester imide)s Molecular chain flexibility Dielectric properties Humidity absorption

Microstructure and properties of coarse-grained WC-10Co cemented carbides with different carbon contents during heat treatments

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Rare Metals 2024年第4期43卷 1786-1792页

作者： Yuan-feng Xie Xing-Cheng Xie Zhong-Wu li Rui-Jun Cao Zhong-kun lin Qing li Chen-Guang lin Powder Metallurgy and Special Materials Research Department General Research Institute for Nonferrous MetalsBeijing100088China

The effects of cryogenic treatment(CT)and tempering-cryogenic treatment(TCT)on the microstructure and properties of coarse-grained WC-10Co cemented carbides with different carbon contents were *** binder phase,WC mean grain sizes,W solubility in the binder,relative magnetic s aturation,densities,hardness,wear resistance and second phase precipitation of cemented carbides with different heat treatments were *** results show that there are significant changes of microstructure and properties in the samples with CT and TCT,especially due to the precipitation of metastable nanoparticles W_(x)Co_(y)C_(z) in the binder during the heat treatments of CT and *** the simultaneous combination of microstructure and nanoparticle-reinforced binder,a dramatically improved combination of hardness and wear resistance of the samples after TCT has been achieved.

关键词： Cryogenic treatment Tempering Coarsegrained cemented carbide Carbon content Nanoparticlereinforced binder

Robust chemo-mechanical stability of additives-free SiO_(2)anode realized by honeycomb nanolattice for high performance li-ion batteries

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Chinese Chemical Letters 2024年第10期35卷 442-446页

作者： Xinpin Pan Yongjian Cui Zhe Wang Bowen li Hailong Wang Jian Hao feng li Jing li Advanced Energy Storage Materials Lab School of Materials and New EnergyNingxia UniversityYinchuan 750021China School of Chemistry and Chemical Engineering Ningxia UniversityYinchuan 750021China

Silicon-based anodes including Si,Si Oxand SiO_(2)could deliver ultra-large capacities,but degrade fast owing to huge volume change and low ***,large amounts of elastic binder and conductive additives were composited with nanosized silicon-based materials to yield reasonable cycling stability,which nevertheless not only decrease specific capacity but also induce inhomogeneous lithiation/delithiation as well as uneven stress *** nanolattice has exhibited superior mechanical properties which could be ideal structure for silicon-based anodes,but yet faces challenges in integration of chemical reactivity,conductivity and mechanical ***,we fabricate artificial SiO_(2)honeycomb nanolattice consisting of numerous nanoscale SiO_(2)cells interconnected by through-holes,and conformal coating of highly graphitic carbon on the nanolattice is achieved through in situ catalytic ***,the nanolattice is firmly bonded on Cu substrate through atomic interdiffusion irrespective of surface *** unique structure allows fast charge transportation and homogeneous lithiation/delithiation throughout the micron-meter nanolattice,which results in excellent stability and large reversible capacity over 500 cycles at 1 A/*** results highlight design and constructing artificial nanolattice can be an effective way to prevent chemo-mechanical degradation of silicon-based anode materials.

关键词： li-ion batteries Nanolattice SiO_(2)anode Stability Conductivity