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Acta Metallurgica sinica(English Letters) 2004年第6期17卷 830-834页

作者： y.H.li J.Wang y.s.li y.Kshan Dep.ofMaterialscienceandEngineering ShenyangLigongUmversityShenyang110168China InstituteofIndustry NingboPolytechnicNingbo315800China schoolofMaterial＆ChemicalEngineering SouthernInstituteofMetallurgy＇Ganzhou341000China InstituteofMetalResearch TheChineseAcademyofSdencesShenyang110016China

Recrystallization behavior of a low carbon X70 pipeline steel was studied in the plane strain compression condition. It was found that the dynamic recovery but no dynamic recrystal- lization occurred in the current ex... 详细信息

关键词： pipeline steel, plane strain compression, recrystallization, austenite grain boundary

IMPROVED PROCEssING FOR MICROsTRUCTUREs AND MECHANICAL PROPERTIEs OF A COMMERCIAL PIPEliNE sTEEL

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Acta Metallurgica sinica(English Letters) 2005年第2期18卷 121-128页

作者： y.C.Wang y.s.li M.C.Zhao K.yang schoolofMaterial＆ChemicalEngineering JiangxiUniversityofScienceandTechnologyGanzhou341000China InstituteofMetalResearch TheChineseAcademyofSciencesShenyang110016China

The transformation productions of hot-deformation simulation experiments were investigated using a Gleeble-1500 hot simulator for a commercial pipeline steel. Based on the investigation results, the improved thermo-mechanical control processing (TMCP) schedules containing a two stage multi-pass controlled rolling coupled with moderate cooling rates were applied to hot rolling experiments and acicular ferrite dominated microstructure was obtained. Microstructures and mechanical properties of hot rolled plates were related to TMCP processing, and regression equations describing the relation between processing parameters and mechanical properties in the current TMCP were developed, which could be used to predict mechanical properties of the experimental steel during commercially processing. It was found that with an increase in cooling rate after hot rolling, grain size in the microstructure became smaller, the amount of polygonal ferrite decreased and acicular ferrite increased, and accordingly mechanical properties increased.

关键词： hot-deformation simulation thermo-mechanical control processing acicular ferrite dominated microstructure

Gradient structured Copper by Rotationally Accelerated shot Peening

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Journal of Materials science & Technology 2017年第7期33卷 758-761页

作者： X.Wang y.s.li Q.Z.ang y.H.Zhao y.T.Zhu Nano structural Materials Center School of Materials Science and Engineering Nanjing University of Science and Technology Nanjing 210094 China school of Mechanical Engineering Nanjing University of Science and Technology Nanjing 210094 China Department of Materials science and Engineering North Carolina State University Raleigh NC 27695 USA

A new technology-rotationally accelerated shot peening（RAsP）, was developed to prepare gradient structured materials. By using centrifugal acceleration principle and large steel balls, the RAsP technology can produce much higher impact energy compared to conventional shot peening. As a proof-of-concept demonstration, the RAsP was utilized to refine the surface layer in pure copper（Cu） with an average grain size of 85 nm. The grain size increases largely from surface downwards the bulk, forming an800 ？m thick gradient-structured surface layer and consequently a micro-hardness gradient. The difference between the RAsP technology and other established techniques in preparing gradient structured materials is discussed. The RAsP technology exhibits a promoting future for large-scale manufacturing of gradient materials.

关键词： Microstructure Rotationally accelerated shot peening Gradient structure Hardness Copper

Microstructural evolution and mechanical properties of Mg-9.8Gd-2.7y-0.4Zr alloy produced by repetitive upsetting

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Journal of Materials science & Technology 2018年第7期34卷 1067-1075页

作者： H.Zhou H.y.Ning X.L.Ma D.D.yin L.R.Xiao X.C.sha y.D.yu Q.D.Wang y.s.li Nano and Heterogeneous Materials Center School of Materials and EngineeringNanjing University of Science and TechnologyNanjing210094China Institute of Microstructure and Property of Advanced Materials Beijing University of TechnologyBeijing 100124China school of Mechanical and Electrical Engineering Heilongjiang Institute of TechnologyHeilongjiang 150050China school of Materials science and Engineering Harbin University of Science and TechnologyHarbin 150040China Department of Materials science&Engineering North Carolina State UniversityRaleighNC 27695USA Key Laboratory of Advanced Technologies of Materials Ministry of EducationSchool of Materials Science and EngineeringSouthwest Jiaotong UniversityChengduSichuan 610031China National Engineering Research Center of light Alloys Net Forming and State Key Laboratory of Metal Matrix CompositeShanghai Jiao Tong University200240 ShanghaiChina

A newly developed severe plastic deformation （sPD） technique, i.e. repetitive upsetting （RU）, is employed to improve the strength and ductility of a Mg-Gd-y-Zr alloy. During the RU processing, dynamic recrystallization occurs in the Mg alloy, which leads to a significant grain refinement from 11.2 p.m to 2.8 μm. The yield strength （ys）, ultimate tensile strength （UTs） and elongation increase simultaneously with increasing RU passes. The microstructural evolution is affected by processing temperatures. Dynamic recrystallization prevails at low temperatures, while dynamic recovery is the main effect factor at high temperatures. Texture characteristics gradually become random during multiple passes of RU processing, which reduces the tension-compression asymmetry of the Mg-Gd-y-Zr alloy. 2018 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials science ＆ Technology.

关键词： severe plastic deformation (sPD) Repetitive upsetting (RU) Mg-RE alloy Mechanical properties

COMPARIsON OF PERFORMANCE OF VARIOUs MULTIPLE-MODEL ENsEMBLE TECHNIQUEs IN FORECAsTING INTENsITy OF TROPICAL CyCLONE

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Tropical Cyclone Research and Review 2012年第3期1卷 353-360页

作者： NURsALLEH K.CHANG L.s.LEE y.s.li Malaysian Meteorological Department Malaysia Hong Kong Observatory Hong KongChina

The objective of this study was to explore an optimal multiple-model ensemble technique to aid the forecasting of tropical cyclone(TC) intensity. The maximum winds of TCs as forecast by the models of the European Centre for Medium-Range Weather Forecasts, the Japan Meteorological Agency and the National Centers for Environmental Prediction for the period from July 2010 to October 2011 were studied. Performance of various multiple-model ensemble techniques, including equally weighted ensemble, weighted ensemble based on initial forecast error, weighted ensemble based on 12-hour forecast error, bias-corrected equally weighted ensemble and bias-corrected weighted ensemble based on initial forecast error, was verified against the TC intensities post-analysed by the Hong Kong Observatory. Results showed that the equally weighted ensemble technique generally outperformed the best of the individual models and other multiple-model ensemble techniques. The mean absolute errors of the equally weighted ensemble technique were the lowest at 12, 24 and 36-hour forecasts, and the error spreads were generally the smallest from 12 to 72-hour forecasts.

关键词： COMPARIsON TECHNIQUEs TROPICAL CyCLONE

The effect of southeast Asian biomass burning on aerosol and trace gases at a remote site of southwest China

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The effect of Southeast Asian biomass burning on aerosol and...

Exercise preconditioning alleviates ischemia-induced memory deficits by increasing circulating adiponectin

第九届全国气溶胶会议暨第三届海峡两岸气溶胶技术研讨会

作者： C.y.Chan~1 s.C.Zou~2 L.y.Chan~1 y.s.li~1 1 Department of Ctvil and structural Engineering,The Hong Kong Polytechnic University,Hong Kong,China 2 Department of Chemistry,Zhongshan University,Guangzhou,China

Aerosols(PM and PM)and trace gases were measured at a remote mountain site of Tengchong(25.01°N,98.3°E,1960 m a.s.l.)located on southeastern Tibetan Plateau in southwest China in the spring of *** O,CO,PM and PM had average concentrations of 26 ppb,179 ppb,28 and 34μg/m respectively during the sampling ***,high levels of pollution with hourly average 03,CO,PM and PM concentrations up to 59,678 ppb and,158 and 137μg/m respectively were *** average concentration of water soluble potassium ion (K,0.18 and 0.23μg/m for PM and PM respectively),a tracer for biomass burning was lower when comparing with other rural sites of ***,high concentrations of K were observed at a pollution episode(May 4-6,2004).Meteorological analysis suggested that the polluted air mass was caused by biomass burning emission in the southeast Asian(sE Asia) *** preliminary results thus suggested that the emissions from sE Asia and south Asia have relatively stronger impacts on the abundance of aerosols and trace gases in the background atmosphere of southwest China.

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Neural Regeneration Research 2025年第5期20卷 1445-1454页

作者： Meifeng Zheng Borui Zhang sonata s y yau Kwok-Fai so li Zhang Haining Ou Department of Rehabilitation Medicine Guangzhou Medical UniversityGuangzhouGuangdong ProvinceChina Department of Rehabilitation Medicine The Fifth Clinical College of Guangzhou Medical UniversityGuangzhouGuangdong ProvinceChina Key Laboratory of CNs Regeneration(Ministry of Education) Guangdong-Hong Kong-Macao Institute of CNS RegenerationJinan UniversityGuangzhouGuangdong ProvinceChina Department of Rehabilitation sciences The Hong Kong Polytechnic UniversityHong Kong Special Administrative RegionChina state Key Laboratory of Brain and Cognitive science Li Ka Shing Faculty of MedicineThe University of Hong KongHong Kong Special Administrative RegionChina Center for Exercise and Brain science School of PsychologyShanghai University of SportShanghaiChina Neuroscience and Neurorehabilitation Institute University of Health and Rehabilitation SciencesQingdaoShandong ProvinceChina

Cerebral ischemia is a major health risk that requires preventive approaches in addition to drug *** exercise enhances neurogenesis and synaptogenesis,and has been widely used for functional rehabilitation after *** this study,we determined whether exercise training before disease onset can alleviate the severity of cerebral *** also examined the role of exercise-induced circulating factors in these *** mice were subjected to 14 days of treadmill exercise training before surgery for middle cerebral artery *** found that this exercise pre-conditioning strategy effectively attenuated brain infarct area,inhibited gliogenesis,protected synaptic proteins,and improved novel object and spatial memory *** analysis showed that circulating adiponectin plays a critical role in these preventive effects of *** activation of adiponectin receptors by Adipo Ron mimicked the effects of exercise,while inhibiting receptor activation abolished the exercise *** summary,our results suggest a crucial role of circulating adiponectin in the effects of exercise pre-conditioning in protecting against cerebral ischemia and supporting the health benefits of exercise.

关键词： adiponectin cerebral ischemia exercise pre-conditioning hippocampus memory function middle cerebral artery occlusion prefrontal cortex synaptic proteins treadmill exercise

Interpretable Machine Learning Method for Compressive strength Prediction and Analysis of Pure Fly Ash-based Geopolymer Concrete

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Journal of Wuhan University of Technology(Materials science) 2025年第1期40卷 65-78页

作者： sHI yuqiong li Jingyi ZHANG yang li li Key Laboratory of Agricultural soil and Water Engineering in Arid and semiarid Areas of Ministry of Education Northwest A&F Uni-versityYangling 712100China College of Water Resources and Architectural Engineering Northwest A&F UniversityYangling 712100China Chongqing Key Laboratory of Public Big Data security Technology Chongqing 401420China Chongqing College of Mobile Communication Chongqing 401520China Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina National Rail Transit Electrification and Automation Engineering Technology Research Center(Hong Kong Branch) The Hong Kong Polytechnic UniversityKowloonHung HomHong KongChina

In order to study the characteristics of pure fly ash-based geopolymer concrete(PFGC)conveniently,we used a machine learning method that can quantify the perception of characteristics to predict its compressive *** this study,505 groups of data were collected,and a new database of compressive strength of PFGC was *** order to establish an accurate prediction model of compressive strength,five different types of machine learning networks were used for comparative *** five machine learning models all showed good compressive strength prediction performance on *** them,R2,MsE,RMsE and MAE of decision tree model(DT)are 0.99,1.58,1.25,and 0.25,*** R2,MsE,RMsE and MAE of random forest model(RF)are 0.97,5.17,2.27 and 1.38,*** two models have high prediction accuracy and outstanding generalization *** order to enhance the interpretability of model decision-making,we used importance ranking to obtain the perception of machine learning model to 13 *** 13 variables include chemical composition of fly ash(siO_(2)/Al_(2)O_(3),si/Al),the ratio of alkaline liquid to the binder,curing temperature,curing durations inside oven,fly ash dosage,fine aggregate dosage,coarse aggregate dosage,extra water dosage and sodium hydroxide *** temperature,specimen ages and curing durations inside oven have the greatest influence on the prediction results,indicating that curing conditions have more prominent influence on the compressive strength of PFGC than ordinary Portland cement *** importance of curing conditions of PFGC even exceeds that of the concrete mix proportion,due to the low reactivity of pure fly ash.

关键词： machine learning pure fly ash geopolymer compressive strength feature perception

Constraints on holographic QCD phase transitions from PTA observations

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science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 71-78页

作者： song He li li sai Wang shao-Jiang Wang Center for Theoretical Physics and College of Physics Jilin University school of Physical science and Technology Ningbo University Max Planck Institute for Gravitational Physics (Albert Einstein Institute) CAs Key Laboratory of Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences school of Fundamental Physics and Mathematical sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of Sciences (UCAS) school of Physical sciences University of Chinese Academy of Sciences (UCAS) Theoretical Physics Division Institute of High Energy Physics Chinese Academy of Sciences

The underlying physics of QCD phase transition in the early Universe remains largely unknown due to its strong-coupling nature during the quark-gluon plasma/hadron gas transition, yet a holographic model has been proposed to quantitatively fit the lattice QCD data while with its duration of the first-order phase transition(FoPT) left undetermined. At specific baryon chemical potential, the first-order QCD phase transition agrees with the observational constraint of baryon asymmetry. It, therefore, provides a scenario for phase transition gravitational waves(GWs) within the standard model of particle physics. If these background GWs could contribute dominantly to the recently claimed common-spectrum red noise from pulsar timing array(PTA) observations, the duration of this FoPT can be well constrained, and the associated primordial black holes are still allowed by current observations.

关键词： pulsar timing array QCD phase transition gravitational waves primordial black holes

Correlation between the rock mass properties and maximum horizontal stress:A case study of overcoring stress measurements

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 39-48页

作者： Peng li Meifeng Cai shengjun Miao yuan li yu Wang Key Laboratory of Ministry of Education for Efficient Mining and safety of Metal Mines University of Science and Technology BeijingBeijing 100083China state Key Laboratory of Coal Resources and safe Mining China University of Mining and TechnologyXuzhou 221116China

Understanding the mechanical properties of the lithologies is crucial to accurately determine the horizontal stress *** investigate the correlation between the rock mass properties and maximum horizontal stress,the three-dimensional(3D)stress tensors at 89 measuring points determined using an improved overcoring technique in nine mines in China were adopted,a newly defined characteristic parameter C_(ERP)was proposed as an indicator for evaluating the structural properties of rock masses,and a fuzzy relation matrix was established using the information distribution *** results indicate that both the vertical stress and horizontal stress exhibit a good linear growth relationship with *** is no remarkable correlation between the elastic modulus,Poisson's ratio and depth,and the distribution of data points is scattered and ***,there is no obvious relationship between the rock quality designation(RQD)and *** maximum horizontal stress σ_(H) is a function of rock properties,showing a certain linear relationship with the C_(ERP)at the same *** addition,the overall change trend of σ_(H) determined by the established fuzzy identification method is to increase with the increase of C_(ERP).The fuzzy identification method also demonstrates a relatively detailed local relationship betweenσ_H and C_(ERP),and the predicted curve rises in a fluctuating way,which is in accord well with the measured stress data.

关键词： overcoring stress measurements elastic modulus Poisson's ratio rock quality designation maximum horizontal stress fuzzy identification