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Abnormal mechanochemical effect in ultraprecision machining of an additively manufactured precipitation-strengthened high-entropy alloy

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Journal of Materials Science & Technology 2024年第3期170卷 221-237页

作者： Long Xu Yuchao Bai Yunfa Guo Chang ren Xiaohua Tan Yandong Jia Gang Wang Hao Wang Institute of Materials Shanghai UniversityShanghai 200444China Zhejiang Institute of Advanced Materials Shanghai UniversityJiashan 314100China Department of Mechanical engineering National University of SingaporeSingapore 117575Singapore

Recently,researchers have explored the use of precipitation strengthening and finer microstructures with high-density dislocations in additive manufacturing to produce high-entropy alloys(HeAs)with adjustable ***,the inherent surface roughness and lack of machinability research in AMed HeAs limit their engineering *** this study,we systematically investigated the microstructural characteristics,mechanical properties,and machinability of Fe_(29.3)Co_(28.7)Ni_(28.6)Al_(6.8)Ti_(6.6)(at.%)HeAs with three different structures:single FCC phase cellular(SPC),dual precipitation-strengthened(DPS),and single precipitation-strengthened(SPS).These structures were fabricated by selective laser melting and isothermally annealing at 780 and 940℃.Compared to SPC HeA,DPS HeA exhibits a significant increase in yield strength and ultimate tensile strength but with a dramatic sacrifice in *** HeA exhibits similar mechanical properties to SPC HeA due to the pronounced coarsening of L21 *** ultraprecision machining micro-cutting test showed that SPC HeA had a significant mechanochem-ical effect,as evidenced by a sharp drop in cutting force for inked workpieces,but not DPS *** abnormal finding was that the negligible reflection of cutting force for SPS HeAs suggested a negative mechanochemical effect,even though SPS HeA had equally excellent plasticity like SPC *** was found that nanocrystallization-induced strength enhancement and ductility reduction of SPS HeA lead to chips’deformation dominated by shear avalanche rather than chip folding of SPC HeA,which involves the reduction of surface energy and friction of chips’***,these results and our research findings may guide the machining of AMed precipitation-strengthened HeAs and accelerate their engineering ap-plication.

关键词： High-entropy alloy Selective laser melting Precipitation strengthening Machinability Mechanochemical effect

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Spatial correlations in ground motion intensity measuring from the 2023 Türkiye earthquake

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earthquake Research Advances 2024年第1期4卷 14-22页

作者： Guoliang Shao Ruizhi Wen Hongwei Wang Yeifei ren Baofeng Zhou Key Laboratory of earthquake engineering and engineering Vibration Institute of Engineering MechanicsChina Earthquake AdministrationHarbin150080 China Key Laboratory of earthquake Disaster Mitigation Ministry of Emergency ManagementHarbin150080 China

When evaluating an area's seismic risk or resilience,it is necessary to use the spatial correlation to analyze the ground motion parameters of multiple sites together in an *** two large earthquakes in Türkiye provided the possibility for spatial correlation analysis of ground motion intensity measurements in this *** on the strong motion records provided by The Disaster and emergency Management Authority of Türkiye(AFAD),this study uses the local ground motion prediction equation in Türkiye to give spatial correlation analysis of Intensity *** study gives an exponential model based on a semivariogram and compares it with the correlation model obtained from previous studies.

关键词： Spatial correlation Semi-variance Türkiye GMPe

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effect of lanthanum on inclusions in non-oriented electrical steel slabs

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Journal of Iron and Steel Research(International) 2024年第7期31卷 1680-1691页

作者： Qiang ren Zhi-yuan Hu Yun-xia Liu Wei-cheng Zhang Zi-qi Gao Li-feng Zhang School of Mechanical engineering Yanshan UniversityQinhuangdao 066004HebeiChina School of Metallurgical and ecological engineering University of Science and Technology BeijingBeijing 100083China Research and Development Department Shougang Zhixin Qian'an Electromagnetic Material Co.Ltd.Qian'an 064400HebeiChina School of Mechanical and Materials engineering North China University of TechnologyBeijing 100144China

The effect of lanthanum on the characteristics of inclusions in the slab of non-oriented electrical steels was investigated through industrial trials and thermodynamic *** number,size,and chemical composition of inclusions in the surface,one-quarter of thickness and the center of slabs with and without lanthanum addition were statistically analyzed using an automatic inclusion analysis *** the lanthanum-free slab,inclusions were predominately ***_(2)O_(3),MgO,and AlN as well as a small number of Al_(2)O_(3)-MgO-CaO and *** number densities of oxide inclusions and AlN decreased from the surface to the center of the slab,which was ascribed to the difference in cooling intensity during the continuous *** the steel with lanthanum addition,inclusions were modified into LaAlO_(3) and La_(2)O_(2)S and gradually transformed into dual-phase MgO-La_(2)S3 with an increasing distance from the slab surface due to the reaction between the lanthanum-containing inclusion and the steel *** uneven distribution of oxide inclusions along the thickness of the slab was eliminated in the lanthanum-bearing slab because the dissolved oxygen was remarkably decreased by ***-bearing inclusions were more likely to agglomerate AlN by inducing the heterogeneous nucleation of AlN on their surface,while small-size ***_(2)O_(3) inclusions hardly showed a coarsening effect on the size of AlN.

关键词： Lanthanum-Inclusion Non-oriented electrical steel Aluminum nitride Heterogenous nucleation

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Single-source-precursor synthesis and air-plasma ablation behavior of(Ti,Zr,Hf)C/SiC ceramic nanocomposites at 2200℃

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Journal of Advanced Ceramics 2024年第7期13卷 1043-1059页

作者： Li Lu Qingbo Wen Jinrun Hu Tianxing Jiang Xiangchao ren Yalei Wang Yi Zeng Xiang Xiong State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China

Dense monolithic(Ti,Zr,Hf)C/SiC ceramic nanocomposites with four different molar ratios of metallic elements in the(Ti,Zr,Hf)C phase(i.e.,Ti:Zr:Hf=1:1:1,2:3:5,2:3:3,and 1:2:1)were prepared upon pyrolysis of novel(Ti,Zr,Hf)-containing single-source precursors(SSPs),followed by spark plasma sintering(SPS).A thorough characterization was conducted to elucidate the synthesis of the SSPs,polymer-to-ceramic transformation,chemical/phase compositions,and microstructure of the SiTiZrHfC-based *** results revealed the feasibility of synthesizing nanocomposites with high(Ti,Zr,Hf)C contents using the SSP *** nanocomposites were characterized by a unique microstructure with in situ generated(Ti,Zr,Hf)C@C core-shell nanoparticles homogeneously mixed withβ-*** ablation behavior of the nanocomposites was evaluated on an air-plasma device for 60 ***,the nanocomposites exhibited excellent ablation resistance,and the lowest linear ablation rate reached−0.58μm/s at 2200°***,the ablation resistance can be dramatically improved by precisely tailoring the atomic ratios of metal elements within the(Ti,Zr,Hf)C phase via the molecular design of the *** formation of a multiple-oxide layer with both a high-meltingpoint phase((Ti,Zr,Hf)O_(2))and low-melting-point phases((Zr,Hf)TiO4)and glassy SiO_(2),as well as their structure,played a critical role in the enhanced ablation *** uniform distribution of the high-melting-point(Ti,Zr,Hf)O_(2)nano/microparticles throughout the glassy SiO_(2)matrix significantly enhanced the viscosity and stability of the oxide layer by the pinning effect,offering superior protection against the ingress of oxygen atoms and excellent resistance to mechanical erosion.

关键词： ultrahigh-temperature ceramics(UHTCs) multicomponent carbide nanocomposites ablation behavior multiple oxides

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Formation mechanism of fault accommodation zones under combined stress in graben basin:Implications from geomechanical modeling

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Petroleum Science 2024年第1期21卷 54-76页

作者： Qi-Qiang ren Jin-Liang Gao Rong-Tao Jiang Jin Wang Meng-Ping Li Jian-Wei Feng Institute of Sedimentary Geology Chengdu University of TechnologyChengdu 610059SichuanChina PetroChina Research Institute of Petroleum exploration and Development Beijing100083China Jianghan Oilfield Oil and Gas Production Capacity Construction Management Center Chongqing408000China Sinopec Chongqing Fuling Shale Gas exploration and Development Company Chongqing408000China College of energy Chengdu University of TechnologyChengdu 610059SichuanChina School of Geoscience China University of Petroleum(East China)Qingdao 266580ShandongChina

A fault accommodation zone is a type of structure that is defined as regulating displacement and strain between faults *** numbers of fault accommodation zones are being identified in graben basins,indicating the potential exploration target and petroleum accumulation *** study aims to analyze the formation mechanism and development of fault accommodation zones under combined stress by a numerical simulation method considering geomechanical *** three-dimensional(3-D)seismic interpretation and fractal dimension method,exampled with the Dongxin fault zone,the fault activity and fault combination pattern were conducted to quantitatively characterize the activity difference in fault accommodation *** with mechanical experiment test,a geomehcanical model was established for fault accommodation zones in a graben *** the paleostress numerical simulations and structural physical simulation experiment,the developmental characteristics and genetic mechanism of fault accommodation zones were *** by multi movements and combined stresses,three significant tectonic evolution stages of the Dongxing Fault Zone(DXFZ)were distinguished:During the e_(s)^(3)sedimentary period,the large difference in the stress,strain,and rupture distribution in various faults were significant,and this stage was the key generation period for the prototype of the DXFZ,including the FAZ between large-scale *** the e_(s)^(2)sedimentary period,the eW-trending symmetric with opposite dipping normal faults and the Ne-SW trending faults with large scale were furtherly *** junction area of two secondary normal faults were prone to be ruptured,performing significant period for inheriting and developing characteristics of fault accommodation *** the es1 sedimentary period,the high-order faults in the DXFZ exhibited the obvious fault depressions and strike-slip activity,and the fault accommodation zones were

关键词： Fault accommodation zone Graben basin Fault activity Tectonic physical simulation experiment Finite element numerical simulation Dongxin fault zone

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Inhibition of proliferation,migration,and invasiveness of bladder cancer cells through SAPCD2 knockdown

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BIOCeLL 2024年第1期48卷 97-109页

作者： CHONG SHeN JIAJUN YAN YU ren ZHIRONG ZHU XIAOLONG ZHANG SHUIXIANG TAO Department of Urology Shaoxing People’s HospitalShaoxing HospitalZhejiang University School of MedicineShaoxingChina

Introduction:Bladder cancer(BC)has a high incidence and mortality rate *** anaphasepromoting complex domain containing 2(SAPCDC2)is over-expressed in a variety of ***:This study investigated the effects of SAPCD2 knockdown on BC ***:T24 and UMUC3 cell models and the xenografted BC tumor model with SAPCD2 knockdown were established to observe the malignant phenotype of BC cells by cell counting kit-8 assay,colony formation test,wound healing,and Transwell assay,mRNA and proteins expressions were measured with quantitative real-time polymerase chain reaction,western blotting,and tissue *** chloride agonist on the Wnt/β-catenin pathway was used to clarify the molecular mechanism of SAPCD2 ***:SAPCD2 expression was significantly higher in BC cell lines than in SVHUC-1 ***2 knockdown inhibited viability and cloning,hindered the G0/G1 phase of the cell cycle in UMUC3 and T24 cells,and decreased the migration and invasiveness of BC ***2 knockdown inhibited expression levels of cyclin D1,cyclin B1,N-cadherin,vimentin,Snail,β-catenin,c-Myc,and cyclin-dependent kinase 4,while the P21 and e-cadherin were raised by SAPCD2 ***,lithium chloride reversed the effects of SAPCD2 knockdown on the expression levels of the above proteins in UMUC3 and T24 *** vivo,SAPCD2 knockdown inhibited the volume,weight,and expression of Ki-67 andβ-catenin in tumors and increased the e-cadherin ***:SAPCD2 knockdown inhibits the malignant phenotype of BC via a pathway involvingβ-catenin.

关键词： Bladder cancer SAPCD2 β-catenin c-Myc CDK4 Lithium chloride

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Sentiment Analysis Using e-Commerce Review Keyword-Generated Image with a Hybrid Machine Learning-Based Model

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Computers, Materials & Continua 2024年第7期80卷 1581-1599页

作者： Jiawen Li Yuesheng Huang Yayi Lu Leijun Wang Yongqi ren Rongjun Chen School of Computer Science Guangdong Polytechnic Normal UniversityGuangzhou510665China Hubei Province Key Laboratory of Occupational Hazard Identification and Control Wuhan University of Science and TechnologyWuhan430065China

In the context of the accelerated pace of daily life and the development of e-commerce,online shopping is a mainstreamway for consumers to access products and *** understand their emotional expressions in facing different shopping experience scenarios,this paper presents a sentiment analysis method that combines the ecommerce reviewkeyword-generated imagewith a hybrid machine learning-basedmodel,inwhich theWord2Vec-TextRank is used to extract keywords that act as the inputs for generating the related images by generative Artificial Intelligence(AI).Subsequently,a hybrid Convolutional Neural Network and Support Vector Machine(CNNSVM)model is applied for sentiment classification of those keyword-generated *** method validation,the data randomly comprised of 5000 reviews from Amazon have been *** superior keyword extraction capability,the proposedmethod achieves impressive results on sentiment classification with a remarkable accuracy of up to 97.13%.Such performance demonstrates its advantages by using the text-to-image approach,providing a unique perspective for sentiment analysis in the e-commerce review data compared to the existing ***,the proposed method enhances the reliability and insights of customer feedback surveys,which would also establish a novel direction in similar cases,such as social media monitoring and market trend research.

关键词： Sentiment analysis keyword-generated image machine learning Word2Vec-TextRank CNN-SVM

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Finite-size-induced non-Hermitian phase transitions in real space

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Science China(Physics,Mechanics & Astronomy) 2024年

作者： Hongfei Wang Biye Xie Wei ren Department of Physics International Center for Quantum and Molecular Structures Shanghai University School of Science and engineering The Chinese University of Hong Kong

While non-Hermiticity provokes intriguing phenomena without Hermitian counterparts, e.g., the skin effect and the breakdown of bulk-boundary correspondence, attracting extensive attention both in fundamental physics and device engineering, the role of finite sizes therein remains elusive. Here, we propose a class of finite-size-induced non-Hermitian phase transitions, relying upon higher-order topological invariants associated with real-space wave functions. The phase diagrams for general non-Hermitian chiral models are further acquired to demonstrate our topological definition. Such phase transitions are elucidated qualitatively by an effective intercell coupling alteration that depends on finite sizes in respective directions. Besides, we mimic these phenomena by analogizing the circuit Laplacian in finite-size electric circuits with nonreciprocal couplings. The resultant admittance spectra agree with our theoretical predictions. Our findings shed light on the finite-size mechanism of non-Hermitian topological phase transitions and pave the way for applications in switching and sensing.

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exceptional catalytic effect of novel rGO-supported Ni-Nb nanocomposite on the hydrogen storage properties of MgH_(2)

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Journal of Materials Science & Technology 2024年第5期172卷 83-93页

作者： Samuel Guemou Liuting Zhang Shuai Li Yiqun Jiang Tao Zhong Zichuan Lu ren Zhou Fuying Wu Qian Li School of energy and Power Instrumental Analysis CenterJiangsu University of Science and TechnologyZhenjiang 212003China National engineering Research Center for Magnesium Alloys&National Key Laboratory of Advanced Casting Technologies&College of Materials Science and engineering Chongqing UniversityChongqing 400044China Chongqing Institute of New energy Storage Materials and equipment Chongqing 401135China Max Planck Institute for Iron Research Düsseldorf 40237Germany

The design of an excellent active catalyst to improve the sluggish kinetic and thermodynamic properties of magnesium hydride(MgH_(2))remains a great challenge to achieve its practical *** this study,a novel Ni-Nb/rGO nanocomposite catalyst was successfully prepared by one-spot hydrothermal and sub-sequent calcination *** novel Ni-Nb/rGO nanocomposite exhibits an exceptional catalytic effect on improving MgH_(2) sorption ***,the onset desorption temperature of MgH_(2)+10 wt%Ni-Nb/rGO composite is reduced to 198℃,much lower than that of undoped MgH_(2)(330℃).In-terestingly,the composite can release 5.0,5.9,and 6.0 wt%H_(2) within 10 min at 245,260,and 275℃,***,the dehydrogenated MgH_(2)+10 wt%Ni-Nb/rGO composite starts to absorb hydrogen even at room temperature with approximate 2.75 wt%H_(2) uptake at 75℃under 3 MPa H_(2) pressure within 30 min and exhibits excellent stability by maintaining 6.0 wt%hydrogen content after 20 cycles at 300℃.Chou’s model suggests that the de/hydrogenation kinetics of Ni-Nb/rGO-modified MgH_(2) switches from surface penetration model to diffusion model at lower ***,the ac-tivation energies(e a)for the de/hydrogenation of MgH_(2)+10 wt%Ni-Nb/rGO are reduced to 57.8 kJ/mol and 33.9 kJ/mol,which are significantly lower than those of undoped MgH_(2).The work demonstrates that the addition of a novel ternary Ni-Nb/rGO catalyst is an effective strategy to not only boost the sorption kinetics of MgH_(2) but also maintain its cycling property.

关键词： Hydrogen storage materials Magnesium hydride Ni-Nb/rGO Kinetic analysis Catalytic mechanism

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Perfluorinated iodine alkanes promote the differentiation of mouse embryonic stem cells by regulating estrogen receptor signaling

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Journal of environmental Sciences 2024年第3期137卷 443-454页

作者： Zhihua ren Xiaoxi Yang Tingting Ku Qian S.Liu Jiefeng Liang Qunfang Zhou Francesco Faiola Guibin Jiang State Key Laboratory of environmental Chemistry and ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China College of Resources and environment University of Chinese Academy of SciencesBeijing 100049China College of environment and Resource Research Center of Environment and HealthShanxi UniversityTaiyuan 030006China College of Sino-Danish University of Chinese Academy of SciencesBeijing 100049China

Investigating the development toxicity of perfuorinated iodine alkanes(PFIs)is critical,given their estrogenic effects through binding with estrogen receptors(eRs).In the present study,two PFIs,including dodecafuoro-1,6-diiodohexane(PFHx DI)and tridecafuorohexyl iodide(PFHx I),with binding preference to eRαand eRβ,respectively,were selected to evaluate their effects on proliferation and differentiation of the mouse embryonic stem cells(m eSCs).The results revealed that,similar to e_(2),50μmol/L PFHx DI accelerated the cell proliferation of the m *** PFI stimulation at the exposure concentrations of 2–50μmol/L promoted the differentiation of the m eSCs as characterized by the upregulation of differentiation-related biomarkers(i.e.,Otx2 and Dnmt3β)and downregulation of pluripotency genes(i.e.,Oct4,Nanog,Sox2,Prdm14 and Rex1).Comparatively,PFHx DI exhibited higher induction effect on the differentiation of the m eSCs than did PFHx *** tests on eR signaling indicated that both PFI compounds induced exposure concentration-dependent expressions of eR signaling-related biomarkers(i.e.,eRα,eRβand Caveolin-1)in the m eSCs,and the downstream eR responsive genes(i.e.,c-fos,c-myc and c-jun)well responded to PFHx I *** role of eR in PFI-induced effects on the m eSCs was further validated by the antagonistic experiments using an eR inhibitor(ICI).The findings demonstrated that PFIs triggered eR signaling,and perturbed the differentiation program of the m eSCs,causing the potential health risk during early stage of development.

关键词： Perfuorinated iodine alkanes(PFIs) embryonic stem cells(eSCs) Developmental toxicity Cell differentiation estrogen receptor-related signaling

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