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Effect of CR and isothermal holding temperature on miCRostructure and properties of complex phase steel with high formability(CH steel)

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Journal of Iron and Steel Research(International) 2023年第2期30卷 328-337页

作者： Xiao-hong Chu Peng-fei Gao Wei-jian Chen Feng Li Tao Kang Yan Zhao Xian-dong Yin Zheng-zhi Zhao Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing100083China Beijing Laboratory for Modern Transportation Advanced Metal Materials and Processing Technology University of Science and Technology BeijingBeijing100083China Technical Center Shougang Jingtang United Iron and Steel Co.Ltd.Tangshan063200HebeiChina

The effects of CR contents(0.3 and 1.0 wt.%)and isothermal holding temperatures(400,440,and 480℃)on the miCRostructure evolution and properties of complex phase steel with high formability(CH steel)were investigated using dilatometry,scanning electron miCRoscopy,transmission electron miCRoscopy(TEM),and X-ray diffraction.The results show that the miCRostructures of CH steel with 0.3 wt.%CR are ferrite,granular bainite,martensite,and retained austenite,while no ferrite is observed in the miCRostructure of CH steel with 1.0 wt.%CR in the same process.CR promotes the precipitation of(Nb,Ti)C in the high-temperature austenite region through theoretical calculations and TEM observations.CR retards the bainite transformation and refines the grain size of CH steel.Furthermore,as isothermal holding temperature inCReases from 400 to 480℃,the bainite and retained austenite fractions of two CH steels deCRease,while the martensite fraction inCReases in the steels after final quenching.Consequently,the strength has an inCReasing tendency and the total elongation has a deCReasing tendency with inCReasing isothermal temperature.

关键词： Complex phase steel High formability steel CH steel CR Isothermal holding temperature MiCRostructure Mechanical property

酸改性坡缕石对Ni和CR污染土壤的钝化效果

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环境化学 2022年第4期41卷 1348-1355页

作者：陶玲黄磊张晓郡张凌云周怡蕾任珺甘肃省黄河水环境重点实验室兰州730070 兰州交通大学环境与市政工程学院环境生态研究所兰州730070 甘肃瀚兴环保科技有限公司兰州730070

通过钝化实验与盆栽实验研究酸改性坡缕石对土壤中重金属Ni和CR的钝化效果及植物富集的影响,结合可迁移性因子、钝化容量和修复效率对钝化效果进行评价.结果表明,10%和12.5%浓度硫酸处理72 h后的坡缕石对土壤中Ni和CR的钝化效果显著高... 详细信息

通过钝化实验与盆栽实验研究酸改性坡缕石对土壤中重金属Ni和CR的钝化效果及植物富集的影响,结合可迁移性因子、钝化容量和修复效率对钝化效果进行评价.结果表明,10%和12.5%浓度硫酸处理72 h后的坡缕石对土壤中Ni和CR的钝化效果显著高于原矿和其它酸改性处理,与对照相比,钝化容量分别提高了4.96倍与6.57倍.种植在这两种酸改性坡缕石钝化土壤中的植物内Ni和CR的富集量显著低于其它钝化处理,富集量降低了79.77%与61.13%.随着酸改性坡缕石添加量的增加,重金属Ni与CR由酸溶态转化为稳定性较强的可氧化态与残渣态,可迁移性因子整体降低,钝化容量和修复效率提高.酸改性坡缕石添加量为16 g·kg^(-1)时,修复效率和钝化效果显著高于其它处理.酸改性可显著提高坡缕石对土壤重金属的钝化修复效能,并且,酸改性坡缕石具有规模化应用在土壤重金属污染原位修复工程中的潜力.

关键词：坡缕石 Ni CR 钝化富集

Layer-structured CR/CR_(x)N coating via electroplating-based nitridation achieving high deuterium resistance as the hydrogen permeation barrier

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Journal of Advanced Ceramics 2022年第12期11卷 1944-1955页

作者： Liyu ZHENG Heping LI Jun ZHOU Xinluo TIAN Zhongyang ZHENG Long WANG Xinyun WANG Youwei YAN State Key Laboratory of Materials Processing and Die&Mould Technology International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma PhysicsSchool of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China Southwestern Institute of Physics Chengdu 610225China

Hydrogen isotope permeation through structural materials is a key issue for developing nuclear fusion energy,which will cause fuel loss and radioactive pollution.Developing ceramic coatings with high thermal shock and hydrogen resistance is an effective strategy to solve this issue.In this work,a layer-structured CR/CR_(x)N coating was successfully fabricated by a facile electroplatingbased nitridation technique,which is easy,facile,and applicable to coating complex-shaped substrates.The CR/CR_(x)N coating,composed of a bottom Fe/CR interdiffusion zone,a middle CR layer,and a top CR_(x)N layer,exhibits high bonding strength,high anti-thermal-shock ability,and high deuterium permeation resistance.Its bonding strength achieves 43.6 MPa.The CR/CR_(x)N coating remains intact even after suffering 300 thermal shock cycles under a 600℃–water condition.Through optimizing the nitridation temperature,the CR/CR_(x)N coating achieves a deuterium permeation reduction factor(PRF)as high as 3599 at 500℃.Considering its scalable fabrication technique and considerable properties,the developed CR/CR_(x)N coating may serve as a novel high-performance hydrogen permeation barrier in various fields.

关键词： hydrogen permeation CR_(x)N CR electrodeposition thermal shock resistance

寡氧单胞菌、水稻秸秆和蚯蚓协同修复CR(Ⅵ)污染土壤

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农业环境科学学报 2023年第11期42卷 2440-2452页

作者：沈松蓉陈云康茜琳向媛羚耿育红张伟韩颖西南科技大学生命科学与工程学院四川绵阳621010 西南科技大学分析测试中心四川绵阳621010

为探究水稻秸秆和蚯蚓联合抗CR细菌对CR污染土壤的修复效果和机制,本研究通过室内模拟试验探讨细菌(寡氧单胞菌,Stenotrophomonas sp.,F)、水稻秸秆(S)、细菌+水稻秸秆(SF)、水稻秸秆+蚯蚓(赤子爱胜蚓,Eisenia foetida,SE)和细菌+水稻秸... 详细信息

为探究水稻秸秆和蚯蚓联合抗CR细菌对CR污染土壤的修复效果和机制,本研究通过室内模拟试验探讨细菌(寡氧单胞菌,Stenotrophomonas sp.,F)、水稻秸秆(S)、细菌+水稻秸秆(SF)、水稻秸秆+蚯蚓(赤子爱胜蚓,Eisenia foetida,SE)和细菌+水稻秸秆+蚯蚓(SFE)对50、300 mg·kg^(-1) CR(Ⅵ)污染土壤的修复效果,生物有效态CR的变化及总CR和CR(Ⅵ)在各粒径团聚体中的分布。结果表明:在试验早、中、后期各处理的总CR和CR(Ⅵ)去除率逐渐增加,在50、300 mg·kg^(-1) CR(Ⅵ)暴露后期SFE处理的总CR和CR(Ⅵ)去除率最高,其总CR去除率分别为35.68%、35.29%,CR(Ⅵ)去除率分别为99.28%、75.33%。SFE处理显著降低了土壤氧化还原电位,增加了土壤p H和有机质含量,并促进了微团聚体凝聚胶结为大团聚体。在0、50、300 mg·kg^(-1) CR(Ⅵ)暴露下SE处理大团聚体的占比最高,与CK相比分别增加了14.57、9.51、9.85个百分点,与SFE相比分别增加了3.73、4.09、3.28个百分点。各处理对CR化学形态的影响为SFE>SF>SE>S>F,在整个试验过程中除F处理外,其余处理中各化学形态的占比都随试验时间的延长而稳定变化。与CK相比,在50、300 mg·kg^(-1) CR(Ⅵ)暴露后期SFE处理中可交换态的占比分别降低了35.55、21.02个百分点,残渣态的占比分别增加了22.45、12.51个百分点。总CR主要分布在大团聚体中,CR(Ⅵ)主要分布在微团聚体中,所有处理各粒径团聚体中的总CR和CR(Ⅵ)含量都随试验时间的延长而降低,SFE处理显著降低了大团聚体中总CR和微团聚体中CR(Ⅵ)的含量。研究表明,在50、300 mg·kg^(-1) CR(Ⅵ)暴露下水稻秸秆、蚯蚓和寡氧单胞菌协同处理显著增加了土壤总CR和CR(Ⅵ)的去除率,降低了生物有效态CR的占比并改善了CR在团聚体中的分布。

关键词： CR 寡氧单胞菌水稻秸秆蚯蚓土壤团聚体

基于LDHs-DGT的环境中活性态CR原位提取检测方法研究

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农业环境科学学报 2023年第10期42卷 2371-2382页

作者：田佩宁王震张润祺张闯闯周其文赵玉杰农业农村部环境保护科研监测所农业农村部农产品质量安全环境因子控制重点实验室天津300191

为原位监测土壤CR的形态变化,本研究开发了一种以纳米Mg/Al双层氢氧化物(Mg/Al-LDHs)作为结合膜的梯度扩散薄膜(LDHs-DGT)装置,并通过ICP-MS和超痕量六价铬分析仪联用,实现对环境中活性态CR含量及CR(Ⅲ)、CR(Ⅵ)的原位提取、测定。实验... 详细信息

为原位监测土壤CR的形态变化,本研究开发了一种以纳米Mg/Al双层氢氧化物(Mg/Al-LDHs)作为结合膜的梯度扩散薄膜(LDHs-DGT)装置,并通过ICP-MS和超痕量六价铬分析仪联用,实现对环境中活性态CR含量及CR(Ⅲ)、CR(Ⅵ)的原位提取、测定。实验结果表明,该装置中LDHs结合膜对CR(Ⅲ)和CR(Ⅵ)均有较快的吸附速率,其最大吸附量分别是181.27μg·cm^(-2)和176.29μg·cm^(-2),该装置可在pH为5~8、离子强度小于50 mmol·L^(-1)的环境中对CR(Ⅲ)和CR(Ⅵ)实现准确提取,能够有效避免干扰离子对装置的影响,空白背景值为4.9 ng,方法检出限为0.22 ng·mL^(-1),CR(Ⅲ)和CR(Ⅵ)在扩散膜中的扩散系数分别为(3.58±0.02)×10^(-6)cm^(2)·s^(-1)和(7.03±0.09)×10^(-6)cm^(2)·s^(-1)。LDHs-DGT可以高效侦测土壤活性态CR的时空变化态势,并能对CR(Ⅲ)和CR(Ⅵ)的价态变化进行动态监测。

关键词： CR 活性态检测技术梯度扩散薄膜(DGT) 动态监测

Multi-performance evaluation of high-throughput accelerated corrosion test for high-strength low-alloy 921A steel

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JOURNAL OF IRON AND STEEL RESEARCH INTERNATIONAL 2023年第5期31卷 1260-1278页

作者： Du, Cong-cong Qin, Ming-hua Wu, Zhan-fang Li, Dong-ling Zhao, Lei Li, Xiang-yang Wang, Hai-zhou Univ Sci & Technol Beijing Beijing Adv Innovat Ctr Mat Genome Engn Natl Ctr Mat Serv Safety Beijing 100083 Peoples R China Cent Iron & Steel Res Inst Beijing Adv Innovat Ctr Mat Genome Engn Beijing 100081 Peoples R China China Iron & Steel Res Inst Grp Co Ltd Beijing 100081 Peoples R China

The corrosion behavior of high-strength low-alloy 921A steel in a simulated marine atmospheric environment was studied using a high-throughput experimental method. The corrosion behavior, corrosion morphology, and corrosion products of 921A steels were analyzed using various techniques, including corrosion mass loss method, polarization curve, white-light interferometry, scanning electron miCRoscopy, energy-dispersive spectrometry, miCRobeam X-ray fluorescence spectrometry, X-ray diffraction technique, and X-ray photoelectron spectroscopy. The test results indicated that 921A steel exhibits better corrosion resistance than Q450NQR1 steel in simulated harsh atmospheric environments, as evidenced by a lower corrosion mass loss rate throughout the corrosion tests. The corrosion products of both steels consisted of alpha-FeOOH, Fe3O4, and gamma-FeOOH, with alpha-FeOOH being more prevalent in the rust layer of 921A steel than in Q450NQR1 steel. The inner rust layer of 921A steel also exhibited an appositional enrichment region of CR, Ni, Mo, and V, leading to its superior corrosion resistance compared to that of Q450NQR1 steel. The efficacy of high-throughput accelerated corrosion experimental methods was highlighted for evaluating the corrosion resistance of steel materials in harsh environmental conditions. The findings suggest that 921A steel exhibits better corrosion resistance compared to Q450NQR1 steel and has the potential to be more suitable in harsh marine atmospheric environments. The characterization of the rust layer structures and composition reveals the parallel enrichment of certain elements in the inner rust layer of 921A steel, which enhances its corrosion resistance.

关键词： Atmospheric corrosion High-throughput experimental method High-strength low-alloy steel Corrosion characteristics Rust layer Element enrichment CARBON-STEEL ATMOSPHERIC-CORROSION WEATHERING STEEL RUST LAYERS BEHAVIOR MARINE CR NI CU

制革污泥堆场中含CR污泥胶体在不同pH和离子强度条件下稳定性及迁移行为研究

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环境科学学报 2023年第3期43卷 244-254页

作者：徐铁兵师碧玲吕媛康子沨阎秀兰商建英杨潇河北省环境科学研究院石家庄050037 中国科学院地理科学与资源研究所地表格局与模拟重点实验室北京100101 中国科学院大学中丹学院北京100049 中国农业大学土地科学与技术学院北京100193 河北师范大学地理科学学院石家庄050000

制革污泥中含有大量的重金属CR,毒性大,易迁移,会威胁人类健康.本研究以某停用制革污泥露天堆场作为研究对象,在揭示制革污泥污染特征的基础上,提取污泥中的胶体颗粒,研究不同pH、离子强度下含CR污泥胶体稳定性及迁移情况.结果表明,堆... 详细信息

制革污泥中含有大量的重金属CR,毒性大,易迁移,会威胁人类健康.本研究以某停用制革污泥露天堆场作为研究对象,在揭示制革污泥污染特征的基础上,提取污泥中的胶体颗粒,研究不同pH、离子强度下含CR污泥胶体稳定性及迁移情况.结果表明,堆场污泥中CR含量为5170~25000 mg·kg^(-1),CR赋存形态以铁锰氧化物结合态为主,总CR含量表深层污泥之间无明显分异.表层污泥pH=4.35,处于有氧环境,好氧菌与嗜酸菌为优势菌群;深层污泥pH=7.30,处于无氧环境,厌氧菌为优势菌群.深层污泥中含有大量含CR污泥胶体(含CR量为7.851 mg·g^(-1)),在中性和碱性条件下较为稳定,迁移性强;在酸性条件下快速聚沉,迁移性弱.离子强度越高,污泥胶体越容易聚沉、移动性显著降低,且Ca^(2+)比Na^(+)更容易引起污泥胶体的聚沉和弱移动性,因此,向污泥胶体中引入Ca^(2+)可作为降低CR迁移风险的有效途径.本研究成果可为全面认识同类型制革污泥堆场的污染风险评估和修复方案设计提供重要的理论支撑.

关键词： CR 环境条件污泥胶体稳定性迁移行为

Addressing the Issues and Developments Correlated with Envisaged 5G Mobile Technologies: Comprehensive Solutions

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Computers, Materials & Continua 2023年第11期77卷 2205-2223页

作者： Idrees Sarhan Kocher Energy Engineering Department Duhok Polytechnic UniversityDuhok42001Iraq

Fifth Generation(5G)communications are regarded as the cornerstone to household consumer experience improvements and smart manufacturing revolution from the standpoint of industries’objectives.It is anticipated that Envisaged 5G(E5G)mobile technology would be operational in certain developed countries by 2023.The Internet of Things(IoTs)will transform how humans live when combined with smart and integrated sensing devices,such as in-home sensing devices.Recent research is being carried out all over the world to produce a new technique that can be CRucial in the success of the anticipated 5G mobile technology.High output,reduced latency,highly reliable,greater scalability,high performance,capacity,bandwidth efficiency,virtual open-air transmission,and efficient energy mobile wireless communications are all being investigated currently.In this work,a comprehensive path for addressing the difficulties and developments associated with 5G mobile technology is provided.The debate and desCRiption of a complete analysis of current situations,certain characteristics and prospective scenarios,important technologies,problems and advances,and spectrum allocation of envisioned 5G mobile technologies are provided.Furthermore,this paper analyzes the most notable elements of 5G mobile technology,such as Cognitive Radio(CR),flexibility,accessibility,and cloud-based service offers,which will assure 5G mobile technology’s dominance as the main protocol for international communication.Eventually,this paper provides a method for integrating CR with current wireless communication systems,the necessity for further evolution of the E5G network,and the need for comprehensive consideration of architecture evolution and function enhancement to enhance the E5G mobile technologies.

关键词： E5G mobile technologies spectrum allocation pseudo outdoor communication key performance indicators cloudbased services efficient energy CR

Analysis of Cognitive Radio for LTE and 5G Waveforms

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Computer Systems Science & Engineering 2022年第12期43卷 1207-1217页

作者： Ramesh Ramamoorthy Himanshu Sharma A.Akilandeswari Nidhi Gour Arun Kumar Mehedi Masud Centre for Artificial Intelligence Chennai Institute of TechnologyChennaiIndia Department of Computer Science and Engineering JECRC UniversityJaipur303905India Institute of ECE Saveetha School of EngineeringChennaiIndia Department of Electronics and Communication Engineering JECRC UniversityJaipur303905India Department of Computer Science College of Computers and Information TechnologyTaif University11099Saudi Arabia

Spectrum sensing is one of the major concerns in reaching an efficientQuality of service (QOS) in the advanced mobile communication system. Theadvanced engineering sciences such as 5G, device 2 device communications(D2D), Internet of things (IoT), MIMO require a large spectrum for better service.Orthogonal frequency division multiplexing (OFDM) is not a choice in advancedradio due to the Cyclic Prefix (CP), wastage of the spectrum, and so on. Hence, itis important to explore the spectral efficient advanced waveform techniques andcombine a cognitive radio (CR) with the 5G waveform to sense the idle spectrum,which overcomes the spectrum issue. The demand for spectrum is ever inCReasing;however, spectrum is limited and is an acutely scarce resource. To alleviate theissue, techniques like Cognitive Radios (CR) have been devised. However, suchtechniques are non-standardized, and many variations of CR algorithms have beentried and tested. This paper details the several spectrum sensing methods tailoredfor CR. We explain the benefits, uniqueness, and drawbacks of the various techniques to provide a comprehensive review of the scene, including all recent andnovel techniques of CR. Finally, we provided experimental results for the performance of the CR for key 5G and beyond modulation techniques to elaborate thedependency of the CR techniques for CR applications and provide a competitivereview of their performance. Experiments show that the CR integrated withNOMA shows better performance as compared with existing techniques.

关键词： CR Energy detection FBMC NOMA OFDM