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Precipitation and decomposition behaviors of carbides in AISI M2 high-speed steel with nitrogen and mischmetal

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Journal of Central South University 2017年第4期24卷 782-788页

作者： LIU Bao-long Lü Zhi-qing FENG Wei-wei REN Ting-zhi fu wan-tang College of Mechanical Engineering Yanshan University China First Heavy Industries State Key Laboratory of Metastable Material Science and Technology Yanshan University

The behaviors of the precipitation and decomposition of carbides in AISI M2 high-speed steel modified by nitrogen and mischmetal were investigated using DSC, XRD, SEM and TEM. The as-cast microstructure of the experimental steel consists of dendrites of iron matrix, networks of eutectic carbides and secondary carbides. The average distance between networks is about 34 μm. The carbides mainly include M_2C, M(C,N) and M_6C, and their relative contents are 58.5%, 30.3% and 11.2%, respectively. The average spacing between the M_2C fibers is 1.5 μm. The decomposition of M_2C occurs from 897.2 to 1221.5 ℃(heating rate of 200 ℃/h). Some precipitated carbide particles occur in the M_2C matrix after holding for 15 min at 1100 ℃. With increasing holding time, the carbide fibers neck down more and more obviously until they are broken down. The spectral peaks of M_2C almost disappear after holding for 60 min. The spectral peaks of M_6C gradually strengthen with the holding time, and the relative content of M_6C increases to 79.8% after holding for 60 min. After holding for 180 min, the carbide fibers disappear, and the decomposition products consist of fine carbide particles(about 300 nm) and short rod-like carbides(about 3.5 μm).

关键词： high-speed steel metastable carbides decomposition phase transformation refinement

Effect of Cu Content on Aging Precipitation Behaviors of Cu-Rich Phase in Fe-Cr-Ni Alloy

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Journal of Iron and Steel Research International 2010年第5期17卷 63-68页

作者： TAN Shu-ping wanG Zhen-hua CHENG Shi-chang LIU Zheng-dong HAN Jie-cai fu wan-tang School of Astronautics Harbin Institute of Technology Harbin 150001 Heilongjiang China State Key Laboratory of Metastable Materials Science and Technology Yanshan University Qinhuangdao 066004 Hebei China Central Iron and Steel Research Institute Beijing 100081 China

The precipitation characteristics and effect on strengthening mechanism of Cu-rich phases during short-time and long-time aging for Super 304H steels with different Cu content were investigated using X-ray diffraction （XRD）, scanning electron microscope （SEM） and transmission electron microscope （TEM）. The results show that the size of Cu-rich phase particles increases, the interspace of Cu-rich phase particles decreases and the density of Curich phases increases with the increase of Cu content during short-time aging （approximately 800 h） at 650℃ for Super 304H steels. During long-time aging （more than 2 000 h） at 650 ℃, Cu-rich phase precipitates sufficiently and the strengthening effect of Cu-rich phase is preferable in Super 304H steel containing Cu of 4%. The strengthening effect of Cu-rich phase in Super 304H steels containing Cu of 2.2% or 5% is weaker than that with Cu of 4% during long-time aging （more than 2 000 h）.

关键词： heat resistant alloy Cu content Cu-rich phase aging precipitation strengthening

Quantum public-key crypto via EPR pairs

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Science China(Physics,Mechanics & Astronomy) 2025年第1期68卷 54-59页

作者： Xiang-Qun fu Hong-Wei Li Jian-Hong Shi Tan Li wan-Su Bao Henan Key Laboratory of Quantum Information and Cryptography Information Engineering UniversityZhengzhou 450004China Synergetic Innovation Center of Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei 230026China

With the development of quantum computing technology,quantum public-key cryptography is gradually becoming an alternative to the existing classical public-key *** paper designs a quantum trapdoor one-way function via EPR pairs and quantum *** on this,a new quantum public-key cryptosystem is presented,which offers forward security,and can resist the chosen-plaintext attack and chosen-ciphertext *** with the existing quantum public-key cryptos,eavesdropping can be automatically detected in this new quantum public-key cryptosystem under a necessary condition,which is also detailed in the paper.

关键词： quantum public-key crypto trapdoor one-way function EPR pairs

Synergistic effect of bonding heterogeneity and phonon localization in introducing excellent thermoelectric properties in layered heteroanionic NdZnSbO material

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Journal of Energy Chemistry 2025年第1期100卷 259-272页

作者： Da wan Shuwei tang Shulin Bai Xiaodong Li Peng Ai wanrong Guo Tuo Zheng College of Materials Science and Engineering Liaoning Technical UniversityFuxin 123000LiaoningChina Faculty of Chemistry Northeast Normal UniversityChangchun 130024JilinChina

Layered rare-earth metal oxides,harnessing the dual properties of oxides and two-dimensional layered materials,exhibit remarkable thermal stability and quantum confinement ***,this work adopts the first-principles calculation combined with the Boltzmann transport theory to predict the thermoelectric properties of NdZnSbO *** coexistence of weak interlayer van der Waals interactions,robust intralayer ionic bonding,and partial covalent bonding leads to remarkable bonding heterogeneity,which engenders pronounced phonon scattering and imposes constraints on thermal transport along the out-of-plane *** weakened chemical bonds induced by the antibonding states,together with the rattling-like behavior of the Zn atom,culminate in the profound anharmonicity in the layered NdZnSbO *** weakening bond and heavy element contribute to the softness of phonon modes,which significantly diminishes the phonon group *** redistribution-dominated four-phonon scattering process spans a large optical gap,which effectively reduces the lattice thermal *** NdZnSbO compound exhibits direct semiconductor characteristic with a bandgap of 0.73 e V by adopting the Heyd-Scuseria-Ernzerhof(HSE06)functional in combination with spin–orbit coupling(SOC)*** multi-valley feature of NdZnSbO compound augur favorably for band degeneracy,thus amplifying the power ***,an optimal figure-of-merit(ZT)of 3.40 at 900 K is achieved for the n-type NdZnSbO *** present study delves deeply insights into the origins for the low thermal conductivity of NdZnSbO compound and proposes an optimization scheme to enhance overall thermoelectric performance.

关键词： Heteroanionic materials Multi-valley characteristics Four-phonon scattering Bonding heterogeneity Rattling-like behavior

Landslide model tests with a miniature 2D principal stress sensor

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Journal of Rock Mechanics and Geotechnical Engineering 2025年第1期17卷 94-105页

作者： Kun Fang Yulei fu Huiming tang tangzhe Gao Pengju An Qiong Wu Faculty of Engineering China University of GeosciencesWuhan430074China Badong National Observation and Research Station of Geohazards China University of GeosciencesWuhan430074China Institute of Rock Mechanics Ningbo UniversityNingbo315211China

Understanding the stress distribution derived from monitoring the principal stress(PS)in slopes is of great *** this study,a miniature sensor for quantifying the two-dimensional(2D)PS in landslide model tests is *** fundamental principle and design of the sensor are *** sensor comprises three earth pressure gages and one gyroscope,with the utilization of three-dimensional(3D)printing *** difficulties of installation location during model preparation and sensor rotation during testing can be effectively overcome using this *** different arrangements of the sensors are tested in verification ***,the application of the sensor in an excavated-induced slope model is *** results demonstrate that the sensor exhibits commendable performance and achieves a desirable level of accuracy,with a principal stress angle error of±5°in the verification *** stress transformation of the slope model,generated by excavation,is demonstrated in the application test by monitoring the two miniature principal stress(MPS)*** sensor has a significant potential for measuring primary stress in landslide model tests and other geotechnical model experiments.

关键词： Landslide Model test Principal stress(PS) Stress measurement

Preparation of silver nanoparticles through the reduction of straw-extracted lignin and its antibacterial hydrogel

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 504-514页

作者： Lou Zhang Shuo Li fu tang Jingkai Zhang Yuetong Kang Hean Zhang Lidong Li State Key Laboratory for Advanced Metals and Materials School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China

Silver nanoparticles(Ag NPs)have attracted attention in the field of biomaterials due to their excellent antibacterial ***,the reducing and stabilizing agents used for the chemical reduction of Ag NPs are usually toxic and may cause water *** this work,Ag NPs(31.2 nm in diameter)were prepared using the extract of straw,an agricultural waste,as the reducing and stabilizing *** analysis revealed that the straw extract contained lignin,the structure of which possesses phenolic hydroxyl and methoxy groups that facilitate the reduction of silver salts into Ag *** surfaces of Ag NPs were negatively charged due to the encapsulation of a thin layer of lignin molecules that prevented their *** the prepared Ag NPs were added to the precursor solution of acrylamide,free radical polymerization was triggered without the need for extra heating or light irradiation,resulting in the rapid formation of an Ag NP-polyacrylamide composite *** inhibition zone test proved that the composite hydrogel possessed excellent antibacterial ability due to the presence of Ag *** prepared hydrogel may have potential applications in the fabrication of biomedical materials,such as antibacterial dressings.

关键词： silver nanoparticles hydrogel straw extraction antibacterial

Tremendously enhanced catalytic performance of Fe(Ⅲ)/peroxymonosulfate process by trace Cu(Ⅱ):A high-valent metals domination in organics removal

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Journal of Environmental Sciences 2025年第1期147卷 487-497页

作者： Jieli Ou Yiqing Liu Linyue Zhang Zhenran wang Yuqi tang Yongsheng fu Dandan Zhao Faculty of Geosciences and Environmental Engineering Southwest Jiaotong UniversityChengdu 611756China

Dissolved copper and iron ions are regarded as friendly and economic catalysts for peroxymonosulfate(PMS)activation,however,neither Cu(Ⅱ)nor Fe(Ⅲ)shows efficient catalytic performance because of the slow rates of Cu(Ⅱ)/Cu(Ⅰ)and Fe(Ⅲ)/Fe(Ⅱ)***,we observed a significant enhancement on the degradation of organic contaminants when Cu(Ⅱ)and Fe(Ⅲ)were coupled to activate PMS in borate(BA)*** degradation efficiency of Rhodamine B(RhB,20μmol/L)reached up to 96.3%within 10 min,which was higher than the sum of individual Cu(Ⅱ)-and Fe(Ⅲ)-activated PMS *** radical,hydroxyl radical and high-valent metal ions(i.e.,Cu(Ⅲ)and Fe(IV))were identified as the working reactive species for RhB removal in Cu(Ⅱ)/Fe(Ⅲ)/PMS/BA system,while the last played a predominated *** presence of BA dramatically facilitated the reduction of Cu(Ⅱ)to Cu(Ⅰ)via chelating with Cu(Ⅱ)followed by Fe(Ⅲ)reduction by Cu(Ⅰ),resulting in enhanced PMS activation by Cu(Ⅰ)and Fe(Ⅱ)as well as accelerated generation of reactive ***,the strong buffering capacity of BA to stabilize the solution pH was satisfying for the pollutants degradation since a slightly alkaline environment favored the PMS activation by coupling Cu(Ⅱ)and Fe(Ⅲ).In a word,this work provides a brand-new insight into the outstanding PMS activation by homogeneous bimetals and an expanded application of iron-based advanced oxidation processes in alkaline conditions.

关键词： Peroxymonosulfate Bimetallic catalyst Borate High-valent metals Complexation

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铸态AZ61镁合金热压缩变形组织变化

材料热处理学报 2009年第5期30卷 39-43页

作者：王少楠唐国翌傅万堂吕知清官磊清华大学深圳研究生院新材料研究所广东深圳518055 燕山大学材料科学与工程学院河北秦皇岛066004

利用Gleeble-1500对铸态AZ61镁合金在变形温度200-500℃,应变速率0.001-1s^-1的条件下进行压缩变形;利用显微结构分析和硬度测试等研究不同变形条件下AZ61镁合金的组织和性能,引用Z值（Zener-Hollomon系数）研究温度和应变速率对AZ61镁... 详细信息

利用Gleeble-1500对铸态AZ61镁合金在变形温度200-500℃,应变速率0.001-1s^-1的条件下进行压缩变形;利用显微结构分析和硬度测试等研究不同变形条件下AZ61镁合金的组织和性能,引用Z值（Zener-Hollomon系数）研究温度和应变速率对AZ61镁合金组织的影响,建立再结晶晶粒尺寸与Z值之间的关系。结果表明：铸态AZ61镁合金在热变形时表现出动态再结晶特征,随温度上升,再结晶容易发生且峰值应力降低,再结晶晶粒尺寸随温度升高而增大;随应变速率上升,峰值应力增大且峰值应力对应的应变量增大,再结晶晶粒尺寸减小;硬度大小的变化也与动态再结晶密切相关。

关键词： AZ61镁合金压缩变形组织再结晶

Fe-1.5C-1.5Cr-2.0Al超高碳钢的等温组织及力学性能

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天津大学学报 2007年第5期40卷 629-633页

作者：石淑琴陈光傅万堂牧正志南京理工大学金属纳米材料与技术联合实验室燕山大学材料科学与工程学院秦皇岛066004 京都大学工学科

利用XRD、SEM、TEM、维氏硬度计和拉伸试验机对Fe-1．5C-1．5Cr-2．0Al超高碳钢经300℃等温淬火后的组织及力学性能进行了研究．组织观察与分析表明，等温淬火组织为超细下贝氏体铁素体、残余奥氏体和未溶渗碳体，并随等温时间延长，残... 详细信息

利用XRD、SEM、TEM、维氏硬度计和拉伸试验机对Fe-1．5C-1．5Cr-2．0Al超高碳钢经300℃等温淬火后的组织及力学性能进行了研究．组织观察与分析表明，等温淬火组织为超细下贝氏体铁素体、残余奥氏体和未溶渗碳体，并随等温时间延长，残余奥氏体体积分数减少，组织细化程度增加．研究发现：等温淬火2—10h，屈服强度为1411—1568MPa，抗拉强度为1632—1744MPa，总延伸率为6．9％～8．5％，硬度为515—532HV。随等温时间的延长，强度和硬度升高，塑性下降．

关键词：超高碳钢等温淬火组织力学性能