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Machine learning guided automatic recognition of crystal boundaries in bainitic/martensitic alloy and relationship between boundary types and ductile-to-brittle transition behavior

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journal of Materials Science & Technology 2021年第25期84卷 49-58页

作者： X.c.Li j.X.Zhao j.H.cong R.D.K.Misra X.M.Wang X.L.Wang c.j.shang collaborative Innovation center of Steel Technology University of Science and Technology BeijingBeijing 100083China Department of Metallurgical Materials and Biomedical EngineeringUniversity of Texas at El Paso500 W.University AvenueEl PasoTX 79968USA

Gradient boosting decision tree(GBDT)machine learning(ML)method was adopted for the first time to automatically recognize and conduct quantitative statistical analysis of boundaries in bainitic microstructure using electron back-scatter diffraction(EBSD)*** spite of lack of large sets of EBSD data,we were successful in achieving the desired accuracy and accomplishing the objective of recognizing the *** with a low model accuracy ofcharacteristic features,the accuracy of the model was significantly enhanced to about 88%when the Euler angle was converted to overall misorientation angle(OMA)and specific misorientation angle(SMA)and considered as important *** this model,the recall score of prior austenite grain(PAG)boundary was~93%,high angle packet boundary(OMA>40°)was~97%,and block boundary was~96%.The derived outcomes of ML were used to obtain insights into the ductile-to-brittle transition(DBTT)***,ML modeling approach suggested that DBTT was not determined by the density of high angle grain boundaries,but significantly influenced by the density of PAG and packet *** study underscores that ML has a great potential in detailed recognition of complex multi-hierarchical microstructure such as bainite and martensite and relates to material performance.

关键词： Machine learning Feature engineering Automatic recognition Lath structure crystallography

Power-law patterns in the Phanerozoic sedimentary records of carbon, oxygen, sulfur,and strontium isotopes

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journal of Palaeogeography 2024年第1期13卷 116-126页

作者： Haitao shang Institute of Ecology and Evolution University of OregonEugeneOR97403USA

Power-law patterns appear in a variety of natural systems on the modern Earth;nevertheless,whether such behaviors appeared in the deep-time environment has rarely been studied. Isotopic records in sedimentary rocks, which are widely used to reconstruct the geological/geochemical conditions in paleoenvironments and the evolutionary trajectories of biogeochemical cycles, offer an opportunity to investigate power laws in ancient geological systems. In this study, I focus on the Phanerozoic sedimentary records of carbon, oxygen, sulfur, and strontium isotopes, which have well documented and extraordinarily comprehensive datasets. I perform statistical analyses on these datasets and show that the variations in the sedimentary records of the four isotopes exhibit power-law behaviors. The exponents of these power laws range between 2.2 and 2.9;this narrow interval indicates that the variations in carbon, oxygen, sulfur, and strontium isotopes likely belong to the same universality class, suggesting that these systematic power-law patterns are governed by universal, scale-free mechanisms. I then derive a general form for these power laws from a minimalistic model based on basic physical principles and geosystem-specific assumptions, which provides an interpretation for the power-law patterns from the perspective of thermodynamics. The fundamental mechanisms regulating such patterns might have been ubiquitous in paleoenvironments, implying that similar power-law behaviors may exist in the sedimentary records of other isotopes.

关键词： Power laws Phanerozoic sedimentary records carbon isotope(δ~(13)c) Oxygen isotope(δ~(18)O) Sulfur isotope(δ~(34)S) Strontium isotope(~(87)Sr/~(86)Sr)

carbonation of Pure Minerals in Portland cement:Evolution in Products as a Function of Water-to-solid Ratio

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journal of Wuhan University of Technology(Materials Science) 2024年第5期39卷 1214-1222页

作者： XIONG Kun shang Xiaopeng LI Hongyan WANG Dan Zhengzhou Lutong Highway construction co. Ltd.Zhengzhou 450052China (Special Glass Key Lab of Hainan Province)&(State Key Laboratory of Marine Resource Utilization in South china Sea) Hainan UniversityHaikou 570228China Department of Architectural Engineering Shandong Urban Construction Vocational CollegeJinan 250103China (State Key Laboratory of High Performance civil Engineering Materials Jiangsu Sobute New Materials Co.Ltd.)&(School of Material Science and EngineeringSoutheast UniversityNanjing 211189China)

Minerals in Portland cement including tricalcium silicate(c_(3)S),β-dicalcium silicate(β-c_(2)S),tricalcium aluminate(c_(3)A),and tetracalcium ferroaluminate(c_(4)AF),show a significantly different activity and product evolution for cO_(2)curing at various water-to-solid *** pure minerals were synthesized and subject to cO_(2)curing in this study to make an in-depth understanding for the carbonation properties of cement-based *** showed that the optimum water-to-solid ratios of c_(3)S,β-c_(2)S,c_(3)A and c_(4)AF were 0.25,0.15,0.30 and 0.40 for carbonation,corresponding to 2 h carbonation degree of 38.5%,38.5%,24.2%,and 21.9%,*** produced calcite duringβ-c_(2)S carbonation decreased as the water-to-solid ratio increased,with an increase in content of metastable cacO_(3)of vaterite and *** thermodynamic stability of cacO_(3)produced during carbonation was c_(3)A>c_(4)AF>β-c_(2)S>c_(3)*** carbonation degree of Portland cement was predicted based on the results of pure minerals and the composition of cement,and the error of predicted production of cacO_(3)was only 1.1%,which provides a potential method to predict carbonation properties of systems with a complex mineral composition.

关键词： accelerated carbonation portland cement calcium carbonate water-to-solid ratio

High-performance,stable coNi LDH@Ni foam composite membrane with innovative peroxymonosulfate activation for 2,4-dichlorophenol destruction

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journal of Environmental Sciences 2024年第7期141卷 235-248页

作者： Yu Liu Weibao Liu Xinrui Gan jiangwei shang Xiuwen cheng college of chemistry and Environmental Science Xinjiang Laboratory of Phase Transitions and Microstructures of Condensed Matter PhysicsYili Normal UniversityYining 835000China Key Laboratory for Environmental Pollution Prediction and control Gansu ProvinceCollege of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China

In this study,the cobalt-nickel layered double hydroxides(coNi LDH)were synthesized with a variety of co/Ni mass ratio,as *** comparison,co1Ni3LDH presented the best peroxymonosulfate(PMS)activation efficiency for 2,4-dichlorophenol ***,coNi LDH@Nickel foam(coNi LDH@NF)composite membrane was constructed for enhancing the stability of catalytic ***,coNi LDH@NF-PMS system exerted high degradation efficiency of 99.22%within 90 min for 2,4-DcP when[PMS]_(0)=0.4 g/L,co^(1)Ni^(3)LDH@NF=2 cm×2 cm(0.2 g/L),reaction temperature=298 *** the surface morphology and structure of the catalyst,it was demonstrated that the coNi LDH@NF composite membrane possessed abundant cavity structure,good specific surface area and sufficient active ***,·OH,SO_(4)·^(-)and^(1)O_(2)played the primary role in the coNi LDH@NF-PMS system for 2,4-DcP decomposition,which revealed the PMS activation mechanism in coNi LDH@NF-PMS ***,this study eliminated the stability and adaptability of coNi LDH@NF composite membrane,proposing a new theoretical basis of PMS heterogeneous catalysts selection.

关键词： coNi LDH@NF composite membrane Peroxymonosulfate 2,4-dichlorophenol Reactive radicals

Recycling of Silicone Rubber from composite Insulator with Pyrolysis Method

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cSEE journal of Power and Energy Systems 2024年第4期10卷 1787-1798页

作者： Ruiqi shang Liming Wang Fanghui Yin Masoud Farzaneh Institute of Advanced Technologies in Energy and Electrical Engineering(IAT3E) Shenzhen International Graduate SchoolTsinghua UniversityShenzhen 518055China Department of Applied Sciences(DSA) University of Quebec at ChicoutimiChicoutimiQC G7H2B1Canada

composite insulators have been widely used in transmission *** being removed from transmission lines,their housing silicone material cannot degrade *** tackle this problem,this paper proposes an effective method to recycle waste insulators by pyrolysis to obtain mullite(3Al_(2)O_(3)·2SiO_(2))with high purity and compact *** recycling process studied will not generate toxic *** thermal degradation process of housing material is investigated by analyzing its degradation products including the gas and residues in *** experimental results indicate that the colorant agent Fe2O3 inside the housing material is beneficial for the generation of mullite by decreasing the temperature of ***,since the transitional alumina generated by the dehydration of aluminum hydroxide(ATH)has a smaller diameter and can better dissolute into the silica phases,ATH is a better choice as the additional aluminum *** comparing the components,structure,and particle size of grains formed at different calcination temperatures,the proposed pyrolysis temperatures of the two stages are 1400◦c and 1600◦c,respectively.

关键词： composite insulator mullite pyrolysis recycling silicone rubber sintering

Revealing effect of Al content on oxidation of novel co-cr-Nb-W carbide-strengthened superalloy

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Rare Metals 2024年第9期43卷 4521-4534页

作者： chen Ling shang-Ping Li jie Hou He-Li Luo central Iron & Steel Research Institute Beijing GAONA Materials&Technology co. Ltd.

The high-temperature oxidation behavior of novel co-cr-Nb-W carbide-strengthened wear-resistance alloys with different Al contents（1wt%, 2wt% and 3wt%）at 950, 1000 and 1050 °c was thoroughly investigated by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and field emission electron probe analyzer. The porous property of Nb c in-situ oxidation products（Nb2O5, co Nb2O6and co4Nb2O9） induces a multi-layered oxide scale with micropores and ***-cr-Nb-W alloy with 1 wt% Al undergoes catastrophic oxidation and spalling above 1000 °c. The outward transportation of cr and co is effectively restrained by a continuous Al2O3scale formed around Nb c in-situ oxidation region when Al content reaches 3 wt%. The β-co Al in co-cr-Nb-W alloy with 3 wt% Al has an oxidation priority over eutectic carbides and the alloy matrix which are both enriched with cr, thereby preventing the formation of cr-depletion area and improving the self-healing ability of the oxide film. A slight change in Al content has a remarkable influence on the cooperative effect of Al and cr and multiplies the antioxidant capacity of co-cr-Nb-W alloy above 1000 °c.

关键词： High-temperature oxidation behavior Microstructure Oxidation kinetics Superalloy Wear-resistant alloy

The Adjustment Analysis Method of the Active Surface Antenna Based on convolutional Neural Network

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Research in Astronomy and Astrophysics 2024年第6期24卷 294-306页

作者： You Ban shang Shi Na Wang Qian Xu Shufei Feng School of Mechanical Engineering Xinjiang UniversityUrumqi 830017China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China School of Mechanical Engineering Dongguan University of TechnologyDongguan 523808China

Active surface technique is one of the key technologies to ensure the reflector accuracy of the millimeter/submillimeter wave large reflector *** antenna is complex,large-scale,and high-precision equipment,and its active surfaces are affected by various factors that are difficult to comprehensively deal *** this paper,based on the advantage of the deep learning method that can be improved through data learning,we propose the active adjustment value analysis method of large reflector antenna based on deep *** method constructs a neural network model for antenna active adjustment analysis in view of the fact that a large reflector antenna consists of multiple panels spliced *** on the constraint that a single actuator has to support multiple panels(usually 4),an autonomously learned neural network emphasis layer module is designed to enhance the adaptability of the active adjustment neural network *** classical 8-meter antenna is used as a case study,the actuators have a mean adjustment error of 0.00252 mm,and the corresponding antenna surface error is0.00523 *** active adjustment result shows the effectiveness of the method in this paper.

关键词： techniques:radar astronomy telescopes methods:analytical methods:numerical

c2-phenyl-substituted benzimidazolium-based covalent organic framework as efficient catalyst for cO_(2) conversion without solvents,metals,and cocatalysts

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Science china chemistry 2024年第2期67卷 551-557页

作者： Zhenzhen Wu jing Wang Lili Liu shang Guo juan Li Xianming Zhang Shanxi Institute for Functional Food Shanxi Agricultural UniversityTaiyuan030031China Institute of crystalline Materials Shanxi UniversityTaiyuan030006China Key Laboratory of Interface Science and Engineering in Advanced Materials College of ChemistryTaiyuan University of TechnologyTaiyuan030024China

covalent organic frameworks(cOFs) are a potential platform for carbon dioxide(cO_(2)) conversion owing to their periodic permanent porosity,adjustable structure,and chemical *** good catalytic performance in cO_(2) conversion,collaborative multifunctions should be strategically integrated into the catalytic system design and *** this study,a four-in-one high-efficiency catalyst was synthesized and tested for cO_(2) cycloaddition to form cyclic *** obtained Tp-MPB-BrcOF had a high nitrogen content,which enhanced its cO_(2) affinity through substantial Lewis acid-base or dipole-quadrupole interactions;moreover,the acid(protons transferring from oxygen(–OH) to nitrogen(–NH)),hydrogen bond donor(hydroxyl group),and Br-(nucleophile group) served as three active sites,further improving the catalyst *** results provide a basis for designing efficient and stable cO_(2)-conversion catalysts.

关键词： covalent organic framework c2-phenyl-substituted benzimidazolium cO_(2)conversion four-in-one catalyst

Pre-reduction of WO_(3)-co_(3)O_(4)by H_(2)-c_(2)H_4 in a fluidized bed

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chinese journal of chemical Engineering 2024年第2期66卷 273-284页

作者： Huijun shang Hengli Li Weijun Li Feng Pan Zhan Du State Key Laboratory of Multiphase complex Systems Institute of Process EngineeringChinese Academy of Sciences(CAS)Beijing 100190China college of chemical Engineering Nanjing Technology UniversityNanjing 211816China School of chemistry and chemical Engineering Shihezi UniversityShihezi 832003China college of chemical Engineering University of Chinese Academy of SciencesBeijing 100049China chinalco Environmental Protection and Energy conservation Group co. Ltd.Xiong’an 071700China

In order to avoid the formation ofηphase(W_(6)co_(6)c or W_(3)co_(3)c)that adversely affects the sintering process and its products in the preparation process of ultra-fine Wc-co powder,a technical route of prereduction of WO_(3)-co_(3)O_(4)to WO_(2)-co and then deep reduction carbonization to Wc-co powder has been *** study mainly investigates the influence of gas partial pressure on the pre-reduction process of WO_(3)-co_(3)O_(4)under a mixed atmosphere of H_(2)-c_(2)H_(4)-Ar at 600℃and establishes the kinetic equations of pre-reduction and carbon *** results indicate that increasing the partial pressure of hydrogen is conducive to the rapid and complete conversion of WO_(3) to WO_(2).High carbon content can be generated by the deposition of c_(2)H_(4),and it hinders the diffusion of the reducing gas;WO_(3)still cannot be completely reduced to WO_(2)as the partial pressure of c_(2)H_(4) increases to 60%.For the carbon evolution of c_(2)H_(4),the carbon amount is positively related to the H_(2)partial pressure,but it shows the highest amount and evolution rate when the ethylene partial pressure is 20%.Based on the reduction rate curves of WO_(3) and carbon evolution rate curves of c_(2)H_(4),the rate equations of pre-reduction and carbon evolution of WO_(3)-co_(3)O_(4)system at 600℃are *** pre-reduction reaction belongs to the first-order reaction,and its equation is expressed as follows:r=-(dw_(WO_(3)))/dt=(9±0.15)×10^(-2)×P_(H_(2))^(0.44)P_(c_(2)H_(4))&(0.57)The carbon deposition rate equation of c_(2)H_(4) can be expressed as follows:r=-(dc_c)/dt=r_f-r_b≌7.35×10^(-2)×P_(c_(2)H_(4))^(0.31)

关键词： Fluidization WO_(3)-co_(3)O_(4) Reduction carbon deposition Rate equation