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Application of tem Based on HTS SQUID Magnetometer in Deep Geological Structure Exploration in the Baiyun Gold Deposit,NE China

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Journal of Earth Science 2021年第1期32卷 1-7页

作者： Junjie Wu Xiaodong Chen Yi Yang Qingquan Zhi Xingchun Wang Jie Zhang Xiaohong Deng Yi Zhao Yue Huang Institute of Geophysical and Geochemical Exploration Chinese Academy of Geological SciencesLangfang 065000China Laboratory of Geophysical Electromagnetic Probing Technologies Ministry of Land and ResourcesLangfang 065000China School of Geology Engineering and Geomatics Chang'an UniversityXi'an 710000China

Exploration of deep mineralization,particularly where the mineralization of interest is covered by a conductive overburden,is still a challenge for the conventional transient electromagnetic(tem)method,which measures tem response using induction coils as the sensor.However,sensors such as fluxgate and superconductive quantum interfere device(SQUID)magnetometers can measure the B-field directly,which can provide more reliable deep information for mineralization exploration.In this paper,we report on the research and development of our newly developed high-temperature su-perconductor(HTS)SQUID magnetometer,which is cooled by liquid nitrogen at 77 K,and its applica-tion in tem measurement for deep exploration in a gold deposit in China.This improved SQUID magnetometer version has a good performance with noise(60 fT/√Hz),slew rate(0.8 mT/S),dynamic range(100 dB),sensitivity(6.25 mV/nT),and bandwidth(DC-20 kHz).To find deep and peripheral ore in the Baiyun gold deposit located in Liaoning Province,NE China,both the SQUID magnetometer and induction coil were used for tem data acquisition.Results show that tem can detect the distribution of local strata and the faults contained within them.Results also indicate that the SQUID magnetome-ter has superior response performance for response over geological targets with slower decay time when compared to the induction coil signals.The SQUID magnetometer is more sensitive at observing the induced-polarization effect which is closely related to the ore-controlling faults.

关键词： tem HTS SQUID magnetometer B-field deep exploration the Baiyun gold deposit

Tunability of the mechanical properties of(Fe_(50)Mn_(27)Ni_(10)Cr_(13))_(100-x)Mo_(x) high-entropy alloys via secondary phase control

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Journal of Materials Science & Technology 2021年第14期73卷 210-217页

作者： Raymond Kwesi Nutor Q.P.Cao X.D.Wang D.X.Zhang J.Z.Jiang International Center for New-Structured Materials(ICNSM) Laboratory of New-Structured MaterialsState Key Laboratory of Silicon Materialsand School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027China State Key Laboratory of Modern Optical Instrumentation Zhejiang UniversityHangzhou 310027China

The single-phase face-centered cubic(fcc)-structured Fe_(50)Mn_(27)Ni_(10)Cr_(13) high entropy alloy(HEA)exhibits good ductility but low strength,which presents a challenge.By Mo-alloying and thermomechanical treatments,we have designed the(Fe_(50)Mn_(27)Ni_(10)Cr_(13))_(100-x)Mo_(x)(x=0-6 at.%)alloy series with a wide range of mechanical properties.The careful control of secondary phases introduced in the cold-rolled and annealed(Fe_(50)Mn_(27)Ni_(10)Cr_(13))Mo_(2) sample resulted in an enhanced tensile strength from 250 MPa to 665 MPa,still having~25%ductility.tem investigations of this alloy revealed the presence of deformation twins,dislocation cells,and ordered bcc na no-pa rticles embedded in the ductile fcc matrix post-deformation.The observed deformation structures are an indication of succes s ful cooperation between deformation twinning and precipitation strengthening in enhancing the tensile strength at maintained ductility compared to its cast counterpart.This work provides insight into the tunability of the mechanical properties of non-equiatomic HEAs via alloying and thermomechanical processing.

关键词： High-entropy alloys Mechanical property tem

Potential aspect of rice husk biomass in Australia for nanocrystalline cellulose production

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Chinese Journal of Chemical Engineering 2018年第3期26卷 465-476页

作者： Md.Sakinul Islam Nhol Kao Sati N.Bhattacharya Rahul Gupta Hyoung Jin Choi Department of Chemical Engineering School of Engineering RMIT University Department of Polymer Science and Engineering Inha University

Nanocrystalline cellulose(NCC) was produced from rice husk biomass(Oryza sativa) by a chemical extraction process to explore the potential aspect of agro-waste biomass in Australia. In this work, the delignified rice husk pulp(D-RHP) was produced by alkaline delignification of raw rice husk biomass(R-RHB) using 4 mol·L^(-1) alkali solutions(Na OH) in a jacketed glass reactor under specific experimental conditions. D-RHP was bleached using 15% sodium hypochlorite, and the bleached rice husk pulp was coded as B-RHP. Finally,raw suspension of NCC was produced by the acid hydrolysis of B-RHP using 4 mol·L^(-1) sulphuric acid. The raw suspension of NCC was neutralized by a buffer solution and analyzed by TAPPI, FT-IR, XRD, SEM, AFM, and tem. FT-IR spectra of NCC are different to R-RHB but similar with B-RHP and D-RHP. From XRD results, the crystallinity of NCC was found to be approximately 65%. In AFM analysis particle thicknesses have been confirmed to be in the range of(25 ± 15.14) nm or(27 ± 15.14) nm which is almost the same. From tem analysis particle dimensions have been confirmed to be in the range of(50 ± 29.38) nm width and(550 ± 302.75) nm length with the aspect ratio ~ 11:1(length/diameter) at a 500 nm scale bar. On the other hand, at a 200 nm scale bar the particle dimensions have been confirmed to be in the range of(35 ± 17) nm width and(275 ± 151.38)nm length with the aspect ratio ~ 8:1. The aspect ratio of individual crystalline domain was determined in tem analysis which is 10:1(100/10). Therefore the aspect ratios and dimensions of nanoparticles in NCC suspension are almost the same and in nano-meter scale, as confirmed from both AFM and tem results. The yield of NCC from B-RHP was found to be approximately 95%, and the recovery of cellulose from R-RHB is about 90%.

关键词：生物资源澳大利亚白米饭纤维素外壳生产粒子尺寸 tem

Preparation of ferromagnetic binary alloy fine fibers by organic gel-thermal reduction process

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中国有色金属学会会刊：英文版 2006年第5期16卷 1003-1008页

作者：沈湘黔曹凯周建新 School of Materials Science and Engineering Jiangsu University

Ferromagnetic metal fibers with a high aspect ratio (length/diameter) are attractive for use as high performance electromagnetic interference shielding materials. Ferromagnetic binary alloy fine fibers of iron-nickel, iron-cobalt and cobalt-nickel were prepared by the organic gel-thermal reduction process from the raw materials of critic acid and metal salts. These alloy fibers synthesized were featured with a diameter of about 1 μm and a length as long as 1 m. The structure, thermal decomposition process and morphologies of the gel precursors and fibers derived from thermal reduction of the gel precursors were characterized by FTIR, XRD, TG/DSC and SEM. The gel spinnability largely depends on the molecular structure of metal- carboxylates formed during the gel formation. The gel consisting of linear-type structural molecules shows good spinnability.

关键词：有机凝胶热还原法铁磁体二元合金光纤可纺性线性结构分子 XRD tem SEM

Enhancing the Antibacterial Efficiency of ZnO Nanopowders Synthesized by Combustion Method Through Ag+Fe Co-doping

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Acta Metallurgica Sinica(English Letters) 2015年第11期28卷 1407-1413页

作者： P.Sathish K.Ravichandran B.Sakthivel A.Panneerselvam Post Graduate and Research Department of Physics AVVM Sri Pushpam College(Autonomous) Post Graduate and Research Department of Botany and Microbiology AVVM Sri Pushpam College(Autonomous)

（Ag ＋ Fe）-doped ZnO nanopowders have been synthesized using combustion method. Ag doping level was kept as 2 at.%, and Fe doping level was varied from 3 to 6 at,%, and the structural, optical, surface morphological, and antibacterial properties have been investigated. The structural studies show that ZnO/（Ag 4-Fe） nanopowders have hexagonal wurtzite structure with a preferential orientation along the （101） plane. The FE-SEM images indicate that there is a gradual decrease in the grain size with the increase in the doping level of Fe, and the tem images are correlated well with FE-SEM images. The XPS profile clearly confirms the presence of expected elemental composition. Photolumi- nescence studies reveal the presence of extrinsic defects in the material. Antibacterial activity of Ag- and Fe-doped ZnO nanopowders against Vibrio parahaemolyticus, Vibrio Cholerae, and Staphylococcus aureus bacteria was also investigated.

关键词： ZnO/Ag/Fe nanopowders Combustion route SEM tem Antibacterial activities

Radiation damage of 1Cr18Ni9Ti and Zr-Ti-Al alloys due to energetic particle irradiation

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Acta Metallurgica Sinica(English Letters) 2012年第1期25卷 29-39页

作者： Maosheng CHAI Wensheng LAI Zhengcao LI Wei FENG Department of Materials Science and Engineering Tsinghua UniversityBeijing 100084China

The radiation damage of 1Cr18Ni9Ti stainless steel and the Zr-Ti-Al alloy by 200 keV Xe＋ ions bombardment at the fluence ranging from 1×1014 to 8×1015 ions/cm2 has been investigated by conventional transmission electron microscope, X-ray diffraction line profile analysis （XRDLPA） and nanoindentation. XRDLPA shows that the order of magnitude of dislocation density in both materials remains almost unchanged up to the highest irradiation dose. Selected-area electron diffraction combined with bright and dark field image indicates that 1Cr18Ni9Ti is more easily damaged than the Zr-Ti-Al alloy. With increasing the ions fluence, the radiation damage became more severe in 1Cr18Ni9Ti, accompanied with phase transition and partial amorphization. The nano-hardness was found to increase rapidly with increasing ion fluence till the dose of 1×1015 ions/cm2, and then gradually saturate with dose. The enhancement of hardness in irradiated materials is due to irradiation-induced defects acting as barriers to dislocation motion.

关键词： Damage structure Zr-Ti-Al alloy 1Cr18Ni9Ti stainless steel XRD tem Irradiation Depth profile

Effects of γ/γ interfacial structures on continuous coarsening of lamellar microstructure in TiAl alloy during aging

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中国有色金属学会会刊：英文版 2004年第1期14卷 37-43页

作者：李臻熙曹春晓 Beijing Institute of Aeronautical Materials Beijing 100095 China

The effects of γ/γ interfacial structures on continuous coarsening of the fully lamellar microstructure in Ti 48Al alloy aged at 1 150 ℃ were investigated by using transmission electron microscopy(tem). Continuous lamellar coarsening can be achieved not only by migration of interface faults(such as ledges, edges and curved interfaces) but also by migration and decomposition of perfect γ/γ lamellar interfaces. Thermal grooves, initiative positions of interfacial dissociation, can frequently form at the triple point junctions between the 120° rotational ordered γ domain boundaries within γ lamellae and the lamellar interfaces. During the early stage of aging at 1 150 ℃, the interface migration and dissociation took place preferentially at the 120° rotational ordered lamellar interfaces. Comparing the relative thermal stability of the true twin, pseudo twin and 120° rotational ordered γ/γ lamellar interfaces shows that the 120° rotational ordered lamellar interface is the most unstable. The reason of this phenomenon was analyzed through the comparisons of the interfacial energies and atomic arrangements of the three types of γ/γ lamellar interfaces.

关键词：时效 TiAl合金界面结构显微结构 tem 晶体生长

Texture Evolution and Ultrafine Grain Formation in Cross-Cryo-Rolled Zircaloy-2

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Acta Metallurgica Sinica(English Letters) 2015年第7期28卷 837-846页

作者： Sunkulp Goel R.Jayaganthan I.V.Singh D.Srivastava G.K.Dey N.Saibaba Department of Metallurgical and Materials Engineering Centre of Nanotechnology Department of Mechanical and Industrial Engineering Materials Science Division Bhabha Atomic Research Center Nuclear Fuel Complex Limited

The texture and mechanical properties of cross-rolled zircaloy-2 at 77 and 300 K were investigated.Crossrolling at 77 K was performed to impart different thickness reductions of 25% and 50%,while at 300 K with 25%,50%,75% and 85% reductions to the sample.EBSD analysis of deformed sample showed that near-basal orientation is not deformed completely after 50% rolling reduction.The activation of prismatic silp,{1122} contraction twin and {1012} extension twin were evident from the deformed microstructure at 77 K.The propensity for activation of basal slip〈a〉 at77 K was also observed.The deformation of the sample at 300 K occurs by prismatic,basal 〈a〉 and pyramidal 〈c＋a〉slips,which were predicted by pole figures.After annealing,the tensile strengths（735 and 710 MPa） are almost the same for 50% cryo-cross-rolled and room-temperature cross-rolled zircaloy-2 with almost 2.7% difference in their ductility.KAM analysis of the deformed samples was made to estimate the stored strain energy and dislocation density.Annealing of deformed sample at 673 K for 30 min results in recrystallization,which leads to the formation of ultrafine grains.

关键词： Cross-rolling EBSD tem Ultrafine grains Texture

A MEMS Device for in-situ tem Test of SCS Nanobeam

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Science China(Technological Sciences) 2008年第9期51卷 1491-1496页

作者： JIN QinHua WANG YueLin LI Tie LI XinXin XU FangFang Shanghai Institute of Microsystem and Information Technology Chinese Academy of SciencesShanghai 200050China Microfabrication of Ministry of Education Institute of Micro and Nano Science and TechnologyShanghai Jiaotong UniversityShanghai 200030China Shanghai Institute of Ceramics Chinese Academy of SciencesShanghai 200050China

In-situ tensile testing in tem (transmission electron microscopy) is a useful tool for studying mechanical properties of nano-structures because it can provide quanti-tative information on sample deformation at atomic scale. To facilitate in-situ tem tensile tests of SCS (single crystal silicon) nanobeam, a MEMS tensile-testing chip was designed and fabricated. The chip was fabricated by means of bulk micro-machining and wafer bonding techniques. An SCS nanobeam, a comb drive ac-tuator, a force sensor beam and an electron beam window were integrated into the chip. With the on-chip comb-drive-actuator stretching the nanobeam and in-situ tem observation, tensile test on a 90 nm-thick nanobeam was performed and the strain-stress relationship was obtained. The Young's modulus was fitted to be 161 GPa and did not show the size effect.

关键词： MEMS tem SCS nanobeam in-situ tensile testing