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Microstructure,wear and friction behavior of CoCrAITaY-xCNTs composite coatings deposited by laser-induction hybrid cladding

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Rare Metals 2024年第4期43卷 1815-1827页

作者： Sheng-Feng Zhou Yu Long Yan-liang yi Cheng Deng Lian-Xi Hu Institute of Advanced Wear&Corrosion Resistant and Functional Materials Jinan UniversityGuangzhou510632China Wuhan National Laboratory for Optoelectronics(WNLO) Huazhong University of Science and TechnologyWuhan430074China MOE Key Laboratory of New Processing Technology for Non-Ferrous Metals and Materials Guangxi Key Laboratory of Processing for Non-Ferrous Metals and Featured MaterialsGuangxi UniversityNanning530004China School of Mechatronics Engineering Guangdong Polytechnic Normal UniversityGuangzhou510635China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin150001China

To improve the wear performance of CoCrAlYTa coating,part of the carbon nanotubes(CNTs)chemically reacted with Ta to form reinforcement phase(TaC),while the other CNTs were retained as lubrication ***,the CoCrAlYTa-xCNTs(x=0,1,2,and 4;wt%)composite coatings were prepared by laserinduction hybrid cladding(LIHC),and the microstructure and wear resistance of coatings were systematically *** show that the coatings are mainly composed of TaC,y-(Co,Cr)andβ-(Co,Cr)*** the CNTs content increases from 0 wt%to 4 wt%,the volume fraction of TaC increases from 13.11 vol%to 16.12 vol%.Meanwhile,the nano-hardness ofγ-(Co,Cr)andβ-(Co,Cr)Al are improved from 7.49 and 9.72 to 9.36 and 11.19 GPa,*** a result,the microhardness of coating increases from HV536.25 to HV 738.16,the wear rate decreases from32.4×10^(-3)to 6.1×10^(-3)mg·m^(-1),and the average friction coefficient decreases from 0.55 to *** good wear performance of the coating is attributed to the formation of TaC and the existence of remained CNTs lubricant film.

关键词： Carbon nanotube MCrAlY coating Friction and wear performance Laser-induction hybrid cladding

Spatiotemporal evolution and driving factors of global production networks:An analysis based on the input-output technique

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Journal of Geographical Sciences 2021年第5期31卷 641-663页

作者： ZHENG Zhi CHEN Wei liang yi ZHANG Yajing Institute of Geographic Sciences and Natural Resources Research CASBeijing 100101China Key Laboratory of Regional Sustainable Development Modeling CASBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China Land Consolidation and Rehabilitation Center Ministry of Natural ResourcesBeijing 100035China

Global production networks have become the most important organizational platforms for coordinating international production activities,and their evolution patterns profoundly affect value distribution across the *** this study,we shall firstly carry out an in-depth quantitative research to analyze the patterns and evolution of global production networks,using a long time-sequenced multi-region input-output table and the network analysis *** based on the method of value-added decomposition,we will develop an index system to measure the degree of participation of regions in global production ***,we will try to identify the factors affecting the degree of participation of countries in global production networks by constructing a regression *** results show that from 1995 to 2015,the evolution of global production networks measured by input-output linkages experienced four stages:expansion,contraction,re-expansion,and *** addition,the core communities of global production networks evolved from two major production communities(Europe and the Americas)to three pillars(Europe,Americas,and Asia)while more segmented communities are mainly affected by geographical *** latter consists of European,North American,South American,African and Asian *** evolution of the global production network pattern primarily manifests as a process of cooperation strengthening or weakening among communities,based on changes in the external environment and the need for individual development ***,the United States,Germany,and the United Kingdom have consistently ranked among the top entities in global production networks,whereas China,Russia,and Southeast Asia have the fastest rises in *** addition,government efficiency,resources endowment,infrastructure conditions and technology levels play important roles in the participation in global production networks.

关键词： input-output table network analysis evolution pattern value-added decomposition participation degree indicator system

Convergence analysis of an incremental approach to online inverse reinforcement learning

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Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第1期12卷 17-24页

作者： Zhuo-jun JIN Hui QIAN Shen-yi CHEN Miao-liang ZHU School of Computer Science and Technology Zhejiang University Hangzhou 310027 China

Interest in inverse reinforcement learning (IRL) has recently increased,that is,interest in the problem of recovering the reward function underlying a Markov decision process (MDP) given the dynamics of the system and the behavior of an *** paper deals with an incremental approach to online ***,the convergence property of the incremental method for the IRL problem was investigated,and the bounds of both the mistake number during the learning process and regret were provided by using a detailed *** an online algorithm based on incremental error correcting was derived to deal with the IRL *** key idea is to add an increment to the current reward estimate each time an action mismatch *** leads to an estimate that approaches a target optimal *** proposed method was tested in a driving simulation experiment and found to be able to efficiently recover an adequate reward function.

关键词： Incremental approach Reward recovering Online learning Inverse reinforcement learning Markov decision process

Enhancement of Selectivity in Capillary Zone Electrophoresis by Adding Ethanolamines or Ethylamines in the Running Buffer

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Chinese Chemical Letters 1997年第11期8卷 985-988页

作者： yi Yang DONG Ai Jin HUANG yi liang SUN(Department of Chemistry Peking University Beijing 100871) Department of Chemistry Peking University Beijing 100871 China

Mono-, di-, tri-ethanolamines and di-, tri-ethylamines were used to prepare phosphate buffer at pH 2.5 and shown to be capable of enhancing the separation selectivity of chiral drug pinacidil and melittin in bee venom in capillary zone electrophoresis. The reason is due to the reduction of the average apparent mobilities of the analytes.

关键词： Enhancement of Selectivity in Capillary Zone Electrophoresis by Adding Ethanolamines or Ethylamines in the Running Buffer

A porous biochar supported nanoscale zero-valent iron material highly efficient for the simultaneous remediation of cadmium and lead contaminated soil

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Journal of Environmental Sciences 2022年第3期34卷 231-241页

作者： Wei Qian Jing-yi liang Wen-Xuan Zhang Shi-Ting Huang Zeng-Hui Diao Guangdong Provincial Engineering and Technology Research Center for Agricultural Land Pollution Prevention and Control Zhongkai University of Agriculture and EngineeringGuangzhou 510225China

Risk associated with heavy metals in soil has been received widespread *** this study,a porous biochar supported nanoscale zero-valent iron(BC-nZVI)was applied to immobilize cadmium(Cd)and lead(Pb)in clayey *** results indicated that the immobilization of Cd or Pb by BC-nZVI process was better than that of BC or nZVI process,and about 80%of heavy metals immobilization was obtained in BC-nZVI *** of BC-nZVI could increase soil pH and organic matter(SOM).Cd or Pb immobilization was inhibited with coexisting organic compound 2,4-dichlorophenol(2,4-DCP),but 2,4-DCP could be removed in a simultaneous manner with Cd or Pb immobilization at low concentration *** immobilization of Cd and Pb was achieved in BC-nZVI process,and both Cd and Pb availability significantly *** Cd species inculding Cd(OH)_(2),CdCO_(3)and CdO were formed,whereas stable Pb species such as PbCO_(3),PbO and Pb(OH)_(2)were produced with BC-nZVI *** immobilization mechanism of Cd and Pb in soil by BC-nZVI was thereby *** study well demonstrates that BC-nZVI has been emerged as a potential technology for the remediation of multiple heavy metals in soil.

关键词： Cadmium(Cd) Lead(Pb) Biochar Nano zero valent iron(nZVI) Contaminated soil

Pt nanoclusters modified porous g-C_(3)N_(4)nanosheets to significantly enhance hydrogen production by photocatalytic water reforming of methanol

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Chinese Journal of Chemical Engineering 2024年第2期66卷 40-50页

作者： yi-Fei liang Jin-Rong Lu Shang-Kun Tian Wen-Quan Cui Li Liu Hebei Provincial Key Laboratory of Environmental Photocatalytic and Electrocatalytic Materials College of Chemical EngineeringNorth China University of Science and TechnologyTangshan 063210China

For the use of green hydrogen energy,it is crucial to have efficient photocatalytic activity for hydrogen generation by water reforming of methanol under mild *** attention has been paid to gC_(3)N_(4)as a promising photocatalyst for the generation of *** improve the separation of photogenerated charge,porous nanosheet g-C_(3)N_(4)was modified with Pt nanoclusters(Pt/g-C_(3)N_(4))through impregnation and following photo-induced *** catalyst showed excellent photocatalytic activity of water reforming of methanol fo r hydrogen production with a 17.12 mmol·g^(-1)·h^(-1)rate at room temperature,which was 311 times higher than that of the unmodified g-C_(3)N_(4).The strong interactions of Pt-N in Pt/g-C_(3)N_(4)constructed effective electron transfer channels to promote the separation of photogenerated electrons and holes *** addition,in-situ infrared spectroscopy was used to investigate the intermediates of the hydrogen production reaction,which proved that methanol and water eventually turn into H_(2)and CO_(2)via formaldehyde and *** study provides insights for understanding the photocatalytic hydrogen production in the water reforming of methanol.

关键词： Water reforming of methanol Photocatalysis g-C_(3)N_(4) Pt nanoclusters Hydrogen production

Magnetic minerals in Mid-Pleistocene sediments on the Caiwei Guyot,Northwest Pacific and their response to the Mid-Brunhes climate event

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Acta Oceanologica Sinica 2021年第12期40卷 1-11页

作者： liang yi Haifeng Wang Geng Liu Yanping Chen Huiqiang Yao Xiguang Deng State Key Laboratory of Marine Geology Tongji UniversityShanghai 200092China Ministry of Natural Resources Key Laboratory of Marine Mineral Resources Guangzhou Marine Geological SurveyChina Geological SurveyGuangzhou 510075China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 510301China Second Institute of Oceanography Ministry of Natural ResourcesHangzhou 310012China

Seamounts are ubiquitous topographic units in global oceans,and their influences on local oceanic circulation have attracted great attention in physical oceanography;however,previous efforts were less made in paleoclimatology and *** Caiwei Guyot in the Magellan Seamounts of the western Pacific is a typical seamount,and in this study,we investigate a well-dated sediment core by magnetic properties to reveal the relationship between deep-sea sedimentary processes and global climate *** principal results are as follows:(1)the dominant magnetic minerals in the sediments are low-coercivity magnetite in pseudo-single domain range,probably including a biogenic contribution;(2)the variabilities of magnetic parameters can be clustered into two sections at~500 ka,and the differences between the two units are evident in amplitudes and means;(3)changes in the grainsize-dependent magnetic parameters can be well correlated to records of global ice volume and atmospheric CO;in the middle *** on these results,a close linkage was proposed between deep-sea sedimentary processes in the Caiwei Guyot and global climate *** linkage likely involves different roles of biogenic magnetite in the sediments between interglacial and glacial intervals,responding to changes in marine productivity and deep-sea circulation and displaying a major change in the MidBrunhes climate ***,we proposed that the sedimentary archives at the bottom of the Caiwei Guyot record some key signals of global climate changes,providing a unique window to observe interactions between various environmental systems on glacial-interglacial timescales.

关键词： Caiwei Guyot middle Pleistocene magnetic properties mid-Brunhes event abyssal sediments western Pacific Magellan Seamounts

Microstructure and texture evolution of TB8 titanium alloys during hot compression

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Rare Metals 2021年第10期40卷 2917-2926页

作者： Qiu-Yue Yang Min Ma Yuan-Biao Tan Song Xiang Fei Zhao yi-Long liang College of Materials and Metallurgy Guizhou UniversityGuiyang 550025China College of Materials Science and Engineering Hunan University of Science and TechnologyXiangtan 411201China

In this study, microstructure and texture evolution of TB8 titanium alloys during hot deformation were investigated by using electron back-scattered diffraction(EBSD) analysis. The results showed that dynamic recrystallization(DRX) behavior of TB8 titanium alloys was drastically sensitive to the strain. As the true strain raised from 0.2 to 0.8, the degree of DRX gradually increased. The nucleation mechanism of recrystallization was observed, including discontinuous dynamic recrystallization(DDRX) resulting from the bulging of original boundaries. Furthermore, continuous dynamic recrystallization(CDRX) occurred because of the transformation of low-angle grain boundaries(LAGBs) to high-angle grain boundaries(HAGBs) in the interior of the original deformed grains. The texture evolution of TB8 titanium alloy during hot deformation process was analyzed in detail, and five texture components were observed,including{001}h100 i,{011}h100 i,{112}h110 i,{111}h110 i, and {111}h112 i. As the true strain increased,deformation textures were gradually weakened due to an increase in the volume fraction of DRX grains. When the true strain was 0.8, the main texture components consisted of the recrystallization texture components of the{001}h100 i and {011}h100 i textures.

关键词： TB8 titanium alloys Hot compression Microstructure Texture evolution

Astronomical tuning and magnetostratigraphy of Neogene biogenic reefs in Xisha Islands, South China Sea

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Science Bulletin 2018年第9期63卷 564-573页

作者： liang yi Zhimin Jian Xinyu Liu Youhua Zhu Daojun Zhang Zhenfeng Wang Chenglong Deng State Key Laboratory of Marine Geology Tongji University Shanghai 200092 China Laboratory for Marine Geology. Qingdao National Laboratory for Marine Science and Technology Qingdao 266061 China China National Offshore Oil Corporation Ltd. Zhanjiang Branch Zhanjiang 524057 China Key Laboratory of Economic Stratigraphy and Palaeogeography Nanjing Institute of Geology and Palaeontology. Chinese Academy of Sciences Nanjing 210008 China State Key Laboratory of Lithospheric Evolution. Institute of Geology and Geophysics. Chinese Academy of Sciences Beijing 100029 China Institutions of Earth Science Chinese Academy of Sciences Beijing 100029 China University of Chinese Academy of Sciences. Beijing 100049 China

Biogenic reefs are one of two major depositional types in the South China Sea, and are constructed by coral, algae and bryozoa. The West Pacific is a major area of biogenic reef development and plays a critical role in the global carbon cycle. However, the lack of geochronological studies in previous works inhibits our understanding of their contributions. Herein, we conduct a cyclostratigraphic and magnetostratigraphic study on Neogene biogenic reefs using the XK–1 core that was drilled at the Shidao Island,Xisha(Paracel) Islands. The main findings of this study are:(1) the establishment of reliable magentostratigraphy for Ledong, Huangliu, Meishan and Sanya Formations;(2) the magnetic susceptibility variation can be inferred as growth index and tuned to the 405–ka long eccentricity cycle;(3) the astronomical geochronology suggests that the bottom ages for Ledong, yinggehai, Huangliu, Meishan,and Sanya Formations are 2.2 Ma, 5.7 Ma, 10.4 Ma, 16.6 Ma, and 24.3 Ma, respectively; and (4) Earth's eccentricity and obliquity played predominant roles in biogenic reef establishment on orbital to tectonic timescales. Thus, the reported geochronology offers an opportunity to test the contributions of various factors and hypothesize their roles in the global carbon cycle in future.

关键词： Astronomical tuning Magentostratigraphy Magnetic susceptibility Biogenic reefs Neogene South China Sea