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Acta Metallurgica Sinica(English Letters) 2002年第1期15卷 123-126页

作者： J.S. Yu c.g. zhou H.B. Xu S.K. gong Department of Materials Science and Engineering Beijing University of Aeronautics and AstronauticsBeijing 100083 China

The oxidations of low pressure plasma sprayed (LPPS) NicrAlY coating on nickel base superalloy were studied at 1050℃ in flows of O2, and mixture of O2 and 5%H2O under atmospheric pressure. Oxide formed on the surface of LPPS NicrAlY coating after oxidation at 1050℃ in pure O2 consisted of Nicr2O4, whereas oxide formed on the surface of LPPS NicrAlY coating after oxidation at 1050℃ in a mixture of O2 and 5%H2O is mainly composed of NiO. The effect of water vapor on the characteristics of the oxide scale is attributed to the increase in Ni cation transport.

关键词： oxidation water vapor coating

cODEPOSITION OF ALUMINUM AND SILIcON ON PURE MOLYBDENUM SUBSTRATE USINg HALIDE AcTIVATED PAcK cEMENTATION TREATMENTS

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Acta Metallurgica Sinica(English Letters) 2002年第2期15卷 167-171页

作者： J.L. Xu, F.S. Liu, c.g. zhou, S.K. gong and H.B. Xu Department of Material Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083, china Dept. of Mat. Sci. and Eng. Beijing Univ. of Aero. and Astron. Beijing 100083 China

A multi-component diffusion coating has been developed to protect Mo-based alloys from high temperature environmental attack. Aluminum addition was made during the coating process to improve the oxidation resistance by developing hexagonal Mo(Si, Al)2 through the development of the halide activated pack cementation coating process on pure Mo substrate. The results show that Mo(Si, Al)2 formed as a main phase on the surface and a little amount of Mo5Si3 also formed. The total thickness of coating is tens ofμm at 1373K. During the cyclic oxidation test at high temperature(at about 1323K in air), mullite (3Al2O3.2SiO2) and some SiO2 formed. The addition of Al is beneficial for MoSi2 coating and the Al-doped coating exhibited only a small weight gain and protected the Mo substrate, while the MoSi2 coating without Al suffered a significant weight loss, indicating a loss of volatile MoO3 after cycles.

关键词： multi-component coating Mo(Si A1)2 halide activated pack cementation 3Al2 O3. 2SiO2 oxidation resistance

A STUDY ON ALUMINIDE cOATINgS ON TiAl ALLOYS BY PAcKcEMENTATION METHOD

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Acta Metallurgica Sinica(English Letters) 2000年第6期13卷 1148-1154页

作者： c.g. zhou, H.B. Xu and S.K. gong (Department of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics,Beijing 100083, china) K. Y. Kim (Department of Materials Science and Engineering, Pohang University of Science and Techn

The halide-activated pack cementation method is utilized to deposit aluminide coat- ings on TiAl alloys. Emphasis is placed on the effect of alloying elements on the aluminizing behavior of TiAl alloy. The addition of a small amount of Nb or cr in the TiAl improves significantly the aluminizing kinetics of TiAl alloys by increasing the solid-state division of Al through the formation of stable TiAl3 layer. The TiAl3 layer formed on the TiAl alloyed with Nb or cr has better toughness than the TiAl3 formed on the non-alloyed TiAl. The reason for better toughness of the coating formed on TiAl is that partial TiAl3 with tetragonal structure was changed to high symmetry cubic L12 structure since Nb or cr was dissolved into TiAl3. The TiAl3 layer formed on the TiAl alloyed with Nb or cr has much better oxidation resistance than the TiAl3 layer formed on the non-alloyed TiAl. It is attributed to change in the crystal structure of TiAl3 from the brittle tetragonal DO22 to the ductile cubic L12 by addition of small amount of Nb or cr.

关键词： TiAl alloying element pack cementation aluminizing

Resident immune responses to spinal cord injury:role of astrocytes and microglia

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Neural Regeneration Research 2024年第8期19卷 1678-1685页

作者： Sydney Brockie cindy zhou Michael g.Fehlings Division of genetics and Development Krembil Research InstituteUniversity Health NetworkTorontoONCanada Institute of Medical Science University of TorontoTorontoONCanada Division of Neurosurgery and Spine Program Department of SurgeryUniversity of TorontoTorontoONCanada

Spinal cord injury can be traumatic or non-traumatic in origin,with the latter rising in incidence and prevalence with the aging demographics of our *** r,as the global population ages,individuals with co-existent degenerative spinal pathology comprise a growing number of traumatic spinal cord injury cases,especially involving the cervical spinal *** makes recovery and treatment approaches particula rly challenging as age and comorbidities may limit regenerative *** these reasons,it is critical to better understand the complex milieu of spinal cord injury lesion pathobiology and the ensuing inflammatory *** review discusses microglia-specific purinergic and cytokine signaling pathways,as well as microglial modulation of synaptic stability and plasticity after ***,we evaluate the role of astrocytes in neurotransmission and calcium signaling,as well as their border-forming response to neural *** the inflammatory and reparative roles of these cells have eluded our complete understanding and remain key therapeutic targets due to their extensive structural and functional roles in the nervous *** advances have shed light on the roles of glia in neurotransmission and reparative injury responses that will change how interventions are *** key processes and existing knowledge gaps will allow future research to effectively target these cells and harness their regenerative potential.

关键词： astrocytes glial signaling microglia spinal cord injury synaptic transmission

The preface: Interplay of topological and magnetic orders in the Mn-Bi-Te family

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National Science Review 2024年第2期11卷 6-7页

作者： Fu-chun Zhang Hai-zhou Lu X.c.Xie Kavli Institute for Theoretical Sciences University of Chinese Academy of Sciences Department of Physics Southern University of Science and Technology (SUSTech) International center for Quantum Materials School of Physics Peking University

The discovery and synthesis of MnBi2Te4in 2013 initially garnered little attention [1]. Yet, the revelation of its topological properties in 2019 [2–6] sparked a surge of research into the MnBiTe family. These extensive studies are primarily driven by two objectives:the realization of a high-temperature quantum anomalous Hall effect （QAHE） and the exploration of exotic phases born from the interplay of topological and magnetic orders,

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Spatial distributions of soil nutrients affected by land use,topography and their interactions,in the Loess Plateau of china

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International Soil and Water conservation Research 2024年第1期12卷 227-239页

作者： Wenxin zhou changjia Li Wenwu Zhao Lindsay c.Stringer Bojie Fu State Key Laboratory of Earth Surface Processes and Resource Ecology Faculty of Geographical ScienceBeijing Normal UniversityBeijingChina Institute of Land Surface System and Sustainable Development Faculty of Geographical ScienceBeijing Normal UniversityBeijingChina Department of Environment and geography University of YorkYorkUK York Environmental Sustainability Institute University of YorkYorkUK

Soil nutrient availability and their spatial distributions are strongly related to land use and landscape *** study aims to address the knowledge gap regarding the interaction between these factors and the underlying *** selected five land uses(grassland with Artemisia gmelinii,woodland with Robinia pseudoacacia,shrubland with caragana korshinskii and Hippophae rhamnoides,and apple orchard with Malus pumila)and nine slope positions across hillslopes in the Loess Plateau,china,to investigate their combined effects on the contents and stocks of soil organic carbon(SOc),total nitrogen(TN)and total phosphorus(TP).Parametric and non-parametric statistical tests were conducted to determine the significant differences in the means or the medians of the soil nutrient *** showed that the SOc and TN contents of shrubland with caragana korshinskii were statistically significantly greater than those of the grassland(pc and TN contents generally decreased from the upper slope to the middle slope,and to the foot slope for the grassland,woodland and shrublands,and on the contrary,an increasing trend from the upper slope,to the middle slope,and to the foot slope was identified for the apple *** study highlights that land use,slope position and their interaction have significant effects on the spatial distributions of soil *** provides essential empirical evidence for the identification of the optimal vegetation type and slope positions in land management and vegetation restoration activities.

关键词： Soil organic carbon Total nitrogen Total phosphorus Slope position Vegetation restoration

Progress on the antiferromagnetic topological insulator MnBi2Te4

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National Science Review 2024年第2期11卷 33-49页

作者： Shuai Li Tianyu Liu chang Liu Yayu Wang Hai-zhou Lu X.c.Xie Department of Physics Harbin Institute of Technology Shenzhen Institute for Quantum Science and Engineering and Department of Physics Southern University of Science and Technology(SUSTech) Quantum Science center of guangdong-Hong Kong-Macao greater Bay Area(guangdong) Shenzhen Key Laboratory of Quantum Science and Engineering International Quantum Academy Beijing Academy of Quantum Information Sciences Beijing Key Laboratory of Optoelectronic Functional Materials&Micro-Nano Devices Department of Physics Renmin University of China State Key Laboratory of Low Dimensional Quantum Physics Department of PhysicsTsinghua University Frontier Science center for Quantum Information Hefei National Laboratory International center for Quantum Materials School of Physics Peking University Institute for Nanoelectronic Devices and Quantum computing Fudan University

Topological materials, which feature robust surface and/or edge states, have now been a research focus in condensed maTher physics. They represent a new class of materials exhibiting nontrivial topological phases,and provide a platform for exploring exotic transport phenomena, such as the quantum anomalous Hall effect and the quantum spin Hall effect. Recently, magnetic topological materials have attracted considerable interests due to the possibility to study the interplay between topological and magnetic *** particular, the quantum anomalous Hall and axion insulator phases can be realized in topological insulators with magnetic order. MnBi2Te4, as the first intrinsic antiferromagnetic topological insulator discovered, allows the examination of existing theoretical predictions; it has been extensively studied, and many new discoveries have been made. Here we review the progress made on MnBi2Te4from both experimental and theoretical aspects. The bulk crystal and magnetic structures are surveyed first, followed by a review of theoretical calculations and experimental probes on the band structure and surface states, and a discussion of various exotic phases that can be realized in MnBi2Te4. The properties of MnBi2Te4thin films and the corresponding transport studies are then reviewed, with an emphasis on the edge state transport. Possible future research directions in this field are also discussed.

关键词： MnBi2Te4 magnetic topological insulator antiferromagnetic quantum anomalous Hall effect axion insulator

Origin and tectonic setting of low-Si alkaline magma

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Science china Earth Sciences 2024年第5期67卷 1417-1435页

作者： Qiushi zhou Rui WANg State Key Laboratory of geological Processes and Mineral Resources and Institute of Earth SciencesChina University of GeosciencesBeijing 100083China Frontiers Science center for Deep-time Digital Earth China University of Geosciences(Beijing)Beijing 100083China

Despite of the relatively rare occurrence of alkaline igneous rocks on Earth, they are the most diverse group of igneous rocks due to variations in their mineral assemblages and geochemical compositions. Alkaline igneous rocks are generally characterized by Si undersaturation, and K-Na(and in some cases c) enrichment. Although there is no unified alkaline igneous rock classification scheme, diagrams such as total alkalis-SiO_(2) or K_(2)O-SiO_(2) can be used to classify alkaline igneous rocks. The origins of silica-saturated alkaline rocks(SiO_(2)>52 wt.%) are relatively complex because multiple episodes of magmatism are often involved, therefore most studies have focused on the origins of silica-undersaturated alkaline *** experimental petrological studies have been conducted in the past few decades. Initially, it was considered that enrichment of trace elements was only achieved by low-degree partial melting of mantle peridotite, but the experimental melts could not reproduce the geochemical composition of natural alkaline igneous rocks. Subsequent studies have focused on carbonate-bearing eclogites that represent the average component of subducted oceanic crust. Although experimental studies indicate that silica-undersaturated and alkali-oversaturated melts can be generated from eclogites, some studies have considered that natural silica-undersaturated alkaline igneous rocks are the result of multi-stage source enrichment by incompatible elements. Low-degree partial melts of the mantle can be emplaced in the lithospheric mantle, forming veins consisting of phlogopite, amphibole, and pyroxene. Melting experiments including these components show that the produced melts better reproduce the naturally occurring silica-undersaturated alkaline magmas. Silica-deficient alkaline igneous rocks occur in various tectonic settings. Those in intraplate and divergent settings(i.e., mainly continental rifts) normally involve contributions from recycled components su

关键词： Alkaline igneous rock Tectonic setting Petrogenesis Big data

Optical measurements of dissolved organic matter as proxies for cOD_(Mn)and BOD_(5)in plateau lakes

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Environmental Science and Ecotechnology 2024年第3期19卷 132-138页

作者： Xuan Yang Yongqiang zhou Xiaoying Yang Yunlin Zhang Robert g.M.Spencer Justin D.Brookes Erik Jeppesen Hucai Zhang Qichao zhou Institute for Ecological Research and Pollution control of Plateau Lakes School of Ecology and Environmental SciencesYunnan UniversityKunming650500China Institute of International River and Eco-security Yunnan UniversityKunming650500China Zhejiang college of Security Technology Wenzhou325016China Taihu Laboratory for Lake Ecosystem Research State Key Laboratory of Lake Science and EnvironmentNanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing210008China Department of Earth Ocean and Atmospheric ScienceFlorida State UniversityTallahassee32306United States Water Research centre School of Biological ScienceThe University of AdelaideAdelaide5005Australia Department of Ecoscience Aarhus UniversityAarhus8000Denmark Sino-Danish centre for Education and Research Chinese Academy of SciencesBeijing100101China Limnology Laboratory Department of Biological Sciences and Centre for Ecosystem Research and ImplementationMiddle East Technical UniversityAnkara06800Turkey Institute of Marine Sciences Middle East Technical UniversityErdemliMersin33731Turkey Yunnan Key Laboratory of Pollution Process and Management of Plateau Lake-Watershed Yunnan Research Academy of Eco-environmental SciencesKunming650034China

The presence of organic matter in lakes profoundly impacts drinking water supplies,yet treatment processes involving coagulants and disinfectants can yield carcinogenic disinfection *** assessments of organic matter,such as chemical oxygen demand(cOD_(Mn))and biochemical oxygen demand(BOD_(5)),are often ***,optical measurements of dissolved organic matter(DOM)offer a rapid and reliable means of obtaining organic matter composition *** we employed DOM optical measurements in conjunction with parallel factor analysis to scrutinize cOD_(Mn)and BOD_(5)*** was performed using an independent dataset encompassing six lakes on the Yungui Plateau from 2014 to 2016(n=256).Leveraging multiple linear regressions(MLRs)applied to DOM absorbance at 254 nm(a254)and fluorescence components c1-c5,we successfully traced cOD_(Mn)and BOD_(5)variations across the entire plateau(68 lakes,n=271,R^(2)>0.8,Pcal indices yielded superior estimates(higher R^(2))of cOD_(Mn)and BOD_(5)during the rainy season compared to the dry season and demonstrated increased accuracy(R^(2)>0.9)in mesotrophic lakes compared to oligotrophic and eutrophic *** study underscores the utility of MLR-based DOM indices for inferring cOD_(Mn)and BOD_(5)variability in plateau lakes and highlights the potential of integrating in situ and remote sensing platforms for water pollution early warning.

关键词： Dissolved organic matter chemical oxygen demand Biochemical oxygen demand Water quality Yungui plateau lakes

consecutive narrow and broad quasi-periodic fast-propagating wave trains associated with a flare

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Science china(Physics,Mechanics & Astronomy) 2024年第5期67卷 200-211页

作者： Xinping zhou Yuandeng Shen chengrui zhou Zehao Tang Ahmed Ahmed Ibrahim college of Physics and Electronic Engineering Sichuan Normal UniversityChengdu 610068China State Key Laboratory of Space Weather Chinese Academy of SciencesBeijing 100190China Yunnan Observatories Chinese Academy of SciencesKunming 650216China Department of Physics and Astronomy College of ScienceKing Saud UniversityP.O.Box 2455Riyadh 11451Saudi Arabia

The excitation mechanism of coronal quasi-period fast-propagating(QFP)wave trains remains *** Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory observations,we study a narrow and a broad QFP wave trains excited one after another during the successive eruptions of filaments hosted within a fan-spine magnetic system on October 20,*** consecutive occurrence of these two types of QFP wave trains in the same event provides an excellent opportunity to explore their excitation mechanisms and compare their physical *** observational results reveal that narrow and broad QFP wave trains exhibit distinct speeds,periods,energy fluxes,and relative intensity amplitudes,although originating from the same active region and being associated with the same gOES c2.9 *** wavelet analysis,we find that the narrow QFP wave train shares a similar period with the flare itself,suggesting its possible excitation through the pulsed energy release in the magnetic reconnection process that generated the accompanying *** the other hand,the broad QFP wave train appears to be associated with the energy pulses released by the successive expansion and unwinding of filament ***,it is plausible that the broad QFP wave train was also excited by the sequential stretching of closed magnetic field lines driven by the erupting *** findings shed light on the different excitation mechanisms and origins of the QFP wave trains.

关键词： narrow wave excitation