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Bulk nanocrystalline W-ti alloys with exceptional mechanical properties and thermal stability

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Journal of Materials Science & technology 2022年第19期114卷 16-28页

作者： H.X.Xue X.C.Cai B.R.Sun X.Shen C.C.Du X.J.Wang t.t.yang S.W.Xin t.D.Shen Clean Nano Energy Center State Key Laboratory of Metastable Materials Science and TechnologyYanshan UniversityQinhuangdao 066004China CSSC 723rd Research Institute China State Shipbuilding Corporation LimitedYangzhou 225000China

Nanocrystalline(NC)W metals and alloys often exhibit higher radiation tolerance and strength than their coarse-grained ***,their thermal stability is low,making it difficult to achieve bulk NC W metals and alloys by consolidation using conventional techniques such as pressure-less sintering,hot-explosive-compaction sintering,and spark plasma *** we report the synthesis and mechanical properties of bulk NC W_(100-x)ti_(x)(x=10 at.%-30 at.%)alloys prepared by consolidating mechanically alloyed NC powders under a high-temperature/high-pressure *** 20 at.%-30 at.%ti largely improves the sinterability of NC W-ti alloy *** room-temperature microhardness and compressive yield strength of consolidated bulk NC W_(80)ti_(20) alloy are∼16.9 and 6.0 GPa,respectively,which are mainly caused by grain boundary strengthening and significantly higher than those of previously reported W and W *** ultimate compressive strength of bulk NC W_(80)ti_(20) measured between 900 and 1100°C deceases with increasing *** behavior can be explained by the activation of Rachinger grain boundary *** grain growth is observed in bulk NC W_(80)ti_(20) after compression at 1000°*** calculation suggests that it is the segregation of ti at grain boundaries that decreases the specific grain boundary free energy and makes the NC W_(80)ti_(20) alloy thermodynamically stable.

关键词： Nanocrystalline W-ti alloys Segregation Grain boundary energy Strength Hardness

PRODUCt IMAGE REtRIEVAL BASED ON CO-FEAtURES OF tHE OBJECt

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Journal of Electronics(China) 2010年第6期27卷 815-821页

作者： Fu Haiyan Kong Xiangwei t yang Nan Zhou Jianhui Chu Fengtao （Faculty of Electronic Information and Electrical Engineering Dalian University of Technology Dalian 116023 China）

In this paper, we propose a product image retrieval method based on the object contour corners, image texture and color. the product image mainly highlights the object and its background is very simple. According to these characteristics, we represent the object using its contour, and detect the corners of contour to reduce the number of pixels. Every corner is described using its approximate curvature based on distance. In addition, the Block Difference of Inverse Probabilities (BDIP) and Block Variation of Local Correlation (BVLC) texture features and color moment are extracted from image's HIS color space. Finally, dynamic time warping method is used to match features with different length. In order to demonstrate the effect of the proposed method, we carry out experiments in Mi-crosoft product image database, and compare it with other feature descriptors. the retrieval precision and recall curves show that our method is feasible.

关键词： Product image retrieval Multi-features Approximate curvature based on distance Block Difference of Inverse Probabilities (BDIP) and Block Variation of Local Correlation (BVLC) texture features Color moment

Phase field modeling of ferroelastic variant switching in yttria-stabilized t'zirconia with strain gradient elasticity and interface tension

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Science China(technological Sciences) 2024年第5期67卷 1443-1457页

作者： ZHOU QianQian WEI YueGuang ZHOU YiChun yang Li College of Engineering BIC-ESATPeking UniversityBeijing100871China School of Advanced Materials and Nanotechnology Xidian UniversityXi’an710126China Frontier Research Center of thin Films and Coatings for Device Applications Academy of Advanced Interdisciplinary ResearchXidian UniversityXi’an710126China

the 6–8 wt%yttria-stabilized zirconia with a tetragonal structure(t’-YSZ)is extensively employed in thermal barrier *** exceptional fracture toughness of t’-YSZ can be attributed to its distinctive ferroelastic toughening *** and interface tension play a critical role in ferroelastic variant switching at the micro-and *** paper presents an original thermodynamically consistent phase field(PF)theory for analyzing ferroelastic variant switching at the micro-and nano-scale of t’-*** theory incorporates strain gradient elasticity using higher-order elastic energy and interface tension tensor via geometric nonlinearity to represent biaxial tension resulting from interface ***,a mixed-type formulation is employed to implement the higher-order theory through the finite element *** an interface in equilibrium,the effects of strain gradient elasticity result in a more uniform distribution of stresses,whereas the presence of interface tension tensor significantly amplifies the stress magnitude at the *** introduction of an interface tension tensor increases the maximum value of stress at the interface by a factor of 4 to *** nucleation and evolution of variants at a pre-existing crack tip in a mono-phase t’-YSZ have also been *** strain gradient elasticity is capable of capturing the size effect of ferroelastic variant switching associated with microstructures in ***,when the grain size approaches that of the specimen,the critical load required for variant switching at the crack tip increases,resulting in greater dissipation of elastic energy during ferroelastic variant ***,the interface tension accelerates the evolution of *** presented framework exhibits significant potential in modeling ferroelastic variant switching at the micro-and nano-scale.

关键词： thermodynamics strain gradient elasticity interface tension phase field method ferroelastic variant switching

Combined effect of WS_(2) and ti_(3)C_(2)t_(x) MXene favors oil-based ultra-low friction on rough steel-steel interface at elevated temperatures

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Science China(technological Sciences) 2024年第7期67卷 1991-2002页

作者： LIU yangQin CHEN Lei WANG yang QIAN LinMao tribology Research Institute State Key Laboratory of Rail Transit Vehicle SystemSchool of Mechanical EngineeringSouthwest Jiaotong UniversityChengdu 610031China Key Laboratory of Advanced technologies of Materials(Ministry of Education) Research Institute of Frontier ScienceSouthwest Jiaotong UniversityChengdu 610031China

the lubrication performance of liquids is severely restricted and is degraded in high-temperature environments. Stable and reliable lubrication in high temperature environments has been a long-standing goal in various industrial fields. In this study,WS_(2)and ti_(3)C_(2)t_(x)MXene nanoflakes were used as oil-based lubricant additives to generate ultra-low friction and even superlubricity(friction coefficient of ~0.007) at elevated temperatures(400℃), which has hitherto not been achieved by both individual pristine materials, WS_(2)and ti_(3)C_(2)t_(x)MXene. Viscosity and thermogravimetric characterization revealed improvements in the high-temperature rheological properties and thermal stability of the lubricating base oil, indicating improved loadbearing and continuous lubrication capabilities at elevated temperatures. X-ray photoelectron spectroscopy, transmission electron microscopy, and atomic force microscopy demonstrated that the formation of an iron/titanium/tungsten-rich oxide lubricious thin film at the sliding interface reduced the interfacial shear stress, which was responsible for the observed friction and wear reductions at high contact pressures(> 1.1 GPa). Although the titanium/tungsten oxide film was gradually removed after prolonged sliding, a sufficiently thick iron oxide film maintained a low friction coefficient for at least 2 h. the improved surface quality facilitates the achievement of ultra-low friction and reduced wear. the proposed lubrication methodology has a broad utilization potential as a wear-reduction strategy across various industrial fields at elevated temperatures.

关键词： ultra-low friction high-temperature wear reduction lubricating additive tungsten disulfide MXene

KINEtICS OF REDUCtION IRON OXIDE IN CaO-SiO_2-Al_2O_3-Fe_tO SLAGS WItH CARBON SAtURAtED IN MOLtEN IRON

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Acta Metallurgica Sinica(English Letters) 1997年第6期10卷 515-522页

作者： X.M. yang D.B. Huang L. t. Kong t.J. yang Y.S. Xie and D. G. Wang(Institute of Chemical Metallurgy, Chinese Academy of Sciences, Beijing 100080, China)(University of Science and technology Beijing, Beijing 100083, China) Inst of Chemical Metallurgy Chinese Acad of Sciences Beijing China

the rate of reducing Fet O in CaO-SiO2-Al2O3-Fet O slags with carbon saturated in molten iron has been determined in a graphite crucible in the temperature range of 1673-1773K. the effects of temperature, slag basicity and FetO content on the reduction rate have also been discussed. test results show that the reduction rate increases with increasing temperature or FEtO concentration in slags, and the reduction rate has a parabolic relation with the simple basicity or optical basicity of slag, the maximum reduction rate being observed at around CaO/SiO2=1.5 of molten slags. the reduction reaction order is 1. 73 or 1.80, and the reduction activation energy is 299.9 or 295.9 kJ/mol in regard to Fet O weight content or Fet O activity calculated by using regular solution model, respectively. the reduction rate of CaO-SiO2-Al2 O3-Fet O slags with carbon saturated in molten iron is in the range of 0.32-3.48 mol-O/cm2·s.

关键词： CaO-SiO_2-Al_2O_3-Fe_tO slags reduction kinetics molten iron,Fe_tO activity

Enhanced helium ion irradiation tolerance in a Fe-Co-Ni-Cr-Al-ti high-entropy alloy with L12 nanoparticles

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Journal of Materials Science & technology 2023年第12期143卷 169-177页

作者： Y.L.Zhao F.L.Meng t.yang J.H.Luan S.F.Liu G.M.Yeli W.t.Lin W.H.Liu X.J.Liu C.t.Liu J.J.Kai School of Materials Science and Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China School of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Department of Materials Science and Engineering Mechanical Behavior Division of Shenyang National Laboratory for Materials ScienceCity University of Hong KongHong KongChina Department of Mechanical Engineering City University of Hong KongHong KongChina Institute of Nuclear&New Energy technology Tsinghua UniversityBeijing 100084China

L12-strengthened high entropy alloys(HEAs)with excellent room and high-temperature mechanical prop-erties have been proposed as promising candidates as structural materials for advanced nuclear ***,knowledge about their radiation response is fairly *** the present work,a novel HEA with a high density of L12 nanoparticles was irradiated with He ion at 500°*** electron microscope(tEM)and atom probe tomography(APt)were employed to study the evolution of mi-crostructural stability and radiation-induced *** to the single-phase FeCoNiCr HEA,the main microstructural features were numerous large faulted dislocation loops and helium *** the irradiation resistance of the present L12-strengthened HEA is much improved in terms of reduced bubble size,which could be attributed to the considerable He trapping efficiency of the coherent pre-cipitate/matrix interface and the enhanced capability of the interface for damage elimination when the matrix channel width is *** analysis revealed that an inverse-Kirkendall-mechanism-dominated radiation-induced segregation(RIS)occurs around bubbles,where a significant Co enrichment and Ni de-pletion can be clearly *** addition,the competing dynamics of ballistic mixing and elemental clustering that raised from the irradiation-enhanced diffusion in a highly supersaturated matrix,along with the low precipitation nucleation barrier due to the small lattice misfit,lead to a dynamical pre-cipitation dissolution and re-precipitation appears under *** a promising phenomenon is expected to promote a potential self-healing effect and could in turn provide a sustainable irradiation tolerance over the operational lifetime of a reactor.

关键词： L12 nanoparticles High-entropy alloy Helium bubble Phase stability Radiation-induced segregation

Impact of oxaliplatin and trastuzumab combination therapy on tumor markers and t lymphocyte subsets for advanced gastric cancer

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World Journal of Gastrointestinal Oncology 2024年第9期16卷 3905-3912页

作者： Cheng-Wan Zheng Yun-Mo yang Hui yang Department of thyroid Surgery The Affiliated Hospital of Southwest Medical UniversityLuzhou 646000Sichuan ProvinceChina

BACKGROUND Advanced gastric cancer(AGC)remains a challenging malignancy with poor *** combination of oxaliplatin and trastuzumab has shown promising results in AGC *** study aimed to investigate the effects of oxaliplatin and trastuzumab combination therapy on serum tumor markers and t lymphocyte subsets in patients with AGC and to explore their potential as predictive biomarkers for treatment *** to investigate the impact of oxaliplatin and trastuzumab combination therapy on serum markers and t cell subsets in patients with *** this prospective study enrolled 60 patients with *** patients received oxaliplatin(130 mg/m^(2),every 3 weeks)and trastuzumab(8 mg/kg loading dose,followed by 6 mg/kg every 3 weeks)for six *** carcinoembryonic antigen(CEA),cancer antigen 19-9(CA19-9),and cancer antigen 72-4(CA72-4)were measured before and after treatment.t-lymphocyte subsets,including CD3+,CD4+,CD8+,and CD4+/CD8+ratios,were also *** clinical response was assessed using the Response Evaluation Criteria in Solid tumors version *** After six cycles of treatment,the CEA,CA19-9,and CA72-4 serum levels significantly decreased compared to baseline levels(Pthe percentages of CD3+and CD4+t lymphocytes increased significantly(Pthe percentage of CD8+t lymphocytes decreased(Pthe CD4+/CD8+ratio also significantly increased after treatment(Ptients with a higher decrease in serum tumor markers(≥50%reduction)and a higher increase in CD4+/CD8+ratio(≥1.5-fold)showed better clinical response rates(Ptin and trastuzumab combination therapy effectively reduced serum tumor marker levels and modulated t lymphocyte subsets in patients with *** therapy not only has a direct antitumor effect,but also enhances the immune response in patients with *** tumor markers and t lymphocyte subsets may serve as potential predictive biomarkers for treatment respon

关键词： Advanced gastric cancer Oxaliplatin trastuzumab Serum tumor markers t lymphocyte subsets Predictive biomarkers

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气相多环芳烃的吸附净化技术研究进展

工程科学学报 2018年第2期40卷 127-135页

作者：李子宜刘应书姜理俊孟苗苗杨雄 Ralph t yang 北京科技大学能源与环境工程学院北京100083 北京科技大学北京高校节能与环保工程研究中心北京100083 密歇根大学化工系安娜堡48109-2136

多环芳烃（PAHs）是近年来在大气污染问题中逐渐受到关注的一类污染物,不仅其自身严重威胁着人体健康,还可作为低挥发性物质促进二次颗粒物的生长.世界多国开始不断通过各种技术手段对废气中PAHs的排放进行控制,PHAs已成为大气环境领域... 详细信息

多环芳烃（PAHs）是近年来在大气污染问题中逐渐受到关注的一类污染物,不仅其自身严重威胁着人体健康,还可作为低挥发性物质促进二次颗粒物的生长.世界多国开始不断通过各种技术手段对废气中PAHs的排放进行控制,PHAs已成为大气环境领域共同关注的热点问题.吸附法是最具潜力且已被工业应用认可的一类PAHs控制净化关键技术,吸附剂对PAHs的吸、脱附性能是其中的关键.目前国内外学者无论是基于传统碳类吸附剂,还是新型的介孔吸附剂,都针对此类特殊低挥发性气体的吸附相平衡、动力学以及脱附特性做了相关研究,探悉了获取PAHs吸脱附最优平衡的关键因素以及最适吸附剂.本文针对这些结果及相关应用进行了综述,对比分析了介孔吸附剂较传统吸附剂在PAHs吸脱附特性上呈现的优势,旨在为PAHs及其他低挥发性气体吸附净化的相关工作提供有效参考.

关键词：多环芳烃大气污染低挥发性气体吸附多孔材料

Molecular Dynamics Simulation Studies on the Micromorphology and Proton transport of Nafion/ti_(3)C_(2)t_(x) Composite Membrane

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Chinese Journal of Polymer Science 2024年第3期42卷 373-387,I0009页

作者： Zhi-Yue Han Su-Peng Pei Chun-yang Yu Yong-Feng Zhou School of Chemical and Environmental Engineering Shanghai Institute of TechnologyShanghai 201418China School of Chemistry&Chemical Engineering Frontiers Science Center for Transformative MoleculesShanghai Key Laboratory of Electrical Insulation and Thermal AgingShanghai Jiao Tong UniversityShanghai 200240China Key Laboratory of Green and High-end Utilization of Salt Lake Resources Chinese Academy of SciencesXining 810008China

the perfluorosulfonic acid(PFSA) membrane doped with two-dimensional conductive filler ti_(3)C_(2)t_(x) is a fuel cell proton exchange membrane with high application potential. Experimental studies showed that the proton conductivity of Nafion/ti_(3)C_(2)t_(x) composite membrane is improved significantly compared with that in pure Nafion. However, the microscopic mechanism of doping on the enhancement of membrane performance is remain unclear now. In this work, molecular dynamics simulation was used to investigate the microscopic morphology and proton transport behaviors of Nafion/ti_(3)C_(2)t_(x) composite membrane at the molecular level. the results shown that there were significant differences about the diffusion kinetics of water molecules and hydroxium ions in Nafion/ti_(3)C_(2)t_(x) at low and high hydration levels in the nanoscale *** the increase of water content, ti_(3)C_(2)t_(x) in membrane was gradually surrounded by ambient water molecules to form a hydration layer, and forming a relatively continuous proton transport channel between Nafion polymer and ti_(3)C_(2)t_(x) monomer. the continuous proton transport channel could increase the number of binding sites of proton and thus achieving high proton conductivity and high mobility of water molecules at higher hydration level. the current work can provide a theoretical guidance for designing new type of Nafion composite membranes.

关键词： Nafion/ti_(3)C_(2)t_(x)composite membrane Proton transport Molecular dynamics simulation