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Properties and microstructure of copper–titanium alloys with magnesium additions

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Rare Metals 2024年第5期43卷 2290-2299页

作者： Lue Huang Li-Jun Peng Jiang Li Xu-Jun Mi Gang Zhao Guo-Jie Huang Hao-Feng Xie Yi-Cheng Cao Wen-Jing Zhang Zhen Yang State Key Laboratory of Nonferrous Metals and processes GRINM Group Co.Ltd.Beijing 100088China GRIMAT Engineering Institute Co. LtdBejing 101407China School of Materials Science and Engineering Northeastern UniversityShenyang110000China General Research Institute for Nonferrous Metals Beijing 100088China China Academy of Space Technology Beijing 100094China China Nonferrous Metals Mining group(Tianjin)Co.Ltd Tianjin 3001llChina

The volume fractions and morphology of precipitates in precipitation-strengthened Cu-Ti alloys,which precipitate mainly as continuous and discontinuous precipitates,are important for the application of the *** study employed hardness and electrical conductivity tests transmission electron microscopy(TEM),atom probe tomography(APT),and first-principles calculations to demonstrate that the addition of Mg is effective for accelerating nanosized continuousβ'-Cu_(4)Ti precipitation as well as for suppressing the precipitation of coarse lamellar discontinuousβ-Cu_(4)Ti precipitates along the grain boundaries,resulting in Cu-Ti alloys with high yield strength and good electrical *** results showed that the continuous precipitation ofβ'-Cu_(4)Ti was accelerated by the Mg additions,which reduced the supersaturation of the matrix,thereby reducing the chemical driving force for the discontinuous *** the other hand,Mg additions increased the mismatch between the discontinuousβ-Cu_(4)Ti precipitates and matrix decreased the nucleation rate of the discontinuous precipitates,and increased the spacing of the discontinuous precipitation layer,resulting in a lower growth rate of the discontinuous ***,the addition of Mg to Cu-Ti alloys enhances the strength and improves the resistance to over-ageing.

关键词： Cu-Ti-Mg alloy Precipitation hardening Discontinuous precipitation Continuous precipitation Microstructure formation mechanism

Late Ordovician Mass Extinction: Earth, fire and ice

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National Science Review 2024年第1期11卷 51-65页

作者： David A.T.Harper Palaeoecosystems group Department of Earth SciencesDurham University

The Late Ordovician Mass Extinction was the earliest of the ‘big’ five extinction events and the earliest to affect the trajectory of metazoan life. Two phases have been identified near the start of the Hirnantian period and in the middle. It was a massive taxonomic extinction, a weak phylogenetic extinction and a relatively benign ecological extinction. A rapid cooling, triggering a major ice age that reduced the temperature of surface waters, prompted a drop in sea level of some 100 m and introduced toxic bottom waters onto the shelves. These symptoms of more fundamental planetary processes have been associated with a range of factors with an underlying driver identified as volcanicity. Volcanic eruptions, and other products, may have extended back in time to at least the Sandbian and early Katian, suggesting the extinctions were more protracted and influential than hitherto documented.

关键词： Ordovician LOME paleoecology palaeobiogeography biotas

Tailoring the surface and interface structures of photocatalysts to enhance hydrogen production

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Science China Chemistry 2024年第4期67卷 1161-1174页

作者： Tao Zhang Pengfei Wang Shuai Yue Fei Li Zhiyong Zhao Sihui Zhan MOE Key Laboratory of Pollution processes and Environmental Criteria/Tianjin Key Laboratory of Environmental Remediation and Pollution Control College of Environmental Science and EngineeringNankai UniversityTianjin 300350China

Photocatalytic water splitting using semiconductor photocatalysts is a promising approach for the production of carbon-neutral,sustainable and clean hydrogen ***,the separation and transport of photoinduced carriers are generally considered to be rate-limiting steps,and their low efficiency remains a major ***,much effort has been devoted to developing new strategies in surface/interface engineering of photocatalysts to improve the dynamics of charge separation/*** feature article briefly summarizes recent advances in photocatalyst surface/interface engineering by our research group,which have been achieved through the design of various novel photocatalysts,including interfacial modulation,heterostructure construction,heteroatom doping,single atom and diatom *** article is divided into three parts:first,we briefly introduce the three key processes involved in solar water splitting and reveal relationships between the properties of nanostructural photocatalysts and the fundamentals of water splitting;second,we detail methods and strategies for surface and interfacial structures to improve the efficiency of the fundamental processes,especially charge separation;finally,we explore prospects for photocatalytic water splitting *** article provides a valuable resource and strategies for researchers currently working in the field of photocatalytic water splitting.

关键词： photocatalytic water splitting surface/interface structures dual-functional photocatalysis

Sludge composition and characteristics shaped microbial community and further determined process performance: A study on full-scale thermal hydrolysis-anaerobic digestion processes

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Journal of Environmental Sciences 2024年第3期137卷 96-107页

作者： Wei Liu Chenxiang Sun Wei Li Tianle Li Zhan Chen Jiawei Wang Zhengran Ren Xianghua Wen School of Environment Tsinghua UniversityBeijing 100084China Jinneng Holding group DatongShanxi 037000China Research and Development Center Beijing Drainage Group Co.Ltd.Beijing 100124China Beijing Dabeinong Science and Technology group Co. Ltd.Beijing 100080China

Anaerobic digestion (AD) with thermal hydrolysis (TH) pretreatment is a promising process for excess sludge treatment,while there lacks of the knowledge from full-scale process about the impact of sludge composition and characteristics on microbial community and *** sludge physiochemical indices,microbial community and performance data of four full-scale TH-AD plants were characterized,and their relationships was *** four plants were operated under almost similar total organic loading rate (OLR)but their methanogenesis performance differentiate into two groups,namely superior group(SupG) and the inferior group (Inf G).In both groups,TH effectively solubilized particulate organic compounds,meanwhile raised the ammonia nitrogen (NH_(4)^(+)-N) and volatile fatty acid (VFA) *** with the Sup G,thermal hydrolyzed sludge of Inf G had higher level of VFAs,NH_(4)^(+)-N and total chemical oxygen demand (t COD),which showed higher inhibition effect on microbes,leading to a community with lower diversity,lower abundance of carbohydrate degrading functional guild,higher protein degrading one,and methanogens that adapted to limited substrates,and further declined the methane production ***,it was recommended that OLR alone was not sufficient for controlling the system in design and operation,the concentration of VFAs,NH_(4)^(+)-N and t COD should be equally *** higher concentration,together with the higher abundance of Defluviitoga and Proteiniphilum were recommended as indicators for inferior running *** results proposed that microbial communities played a role of bridge between environmental factors and performance,provided implications for engineering ecology and operational regulation for full-scale sludge TH-AD process.

关键词： Thermal hydrolysis Anaerobic digestion Microbial community Full-scale

Atomistic mechanism of high ionic conductivity in lithium ytterbium-based halide solid electrolytes:A first-principles study

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Journal of Rare Earths 2024年第1期42卷 155-162,I0006页

作者： Limin Wang Wei Xiao Lu Sun Rong Yang Jinqiu Yu Ligen Wang State Key Laboratory of Nonferrous Metals and processes China GRINM Group Co.Ltd.Beijing100088China GRIMAT Engineering Institute Co. Ltd.Beijing101407China General Research Institute for Nonferrous Metals Beijing100088China China Automotive Battery Research Institute Co. Ltd.Beijing101407China Rare Earth Functional Materials(Xiong'an)Innovation Center Co. Ltd.Xiong'an071700China

As the next generation of commercial automotive power batteries begins replacing liquid lithium batteries,many look towards all-solid-state batteries to pioneer the ***-so lid-state batteries have attracted the attention of countless researchers around the world because of their high safety and high energy *** recent times,halide solid-state electrolytes have become a research hotspot within solid-state electrolytes because of their potentially superior *** this paper,in the framework of DFT,we investigated the atomic mechanisms of improving the ionic conductivity and stability of Li_(3)YbCl_(6).Our calculations show that both trigonal and orthorhombic Li_(3)YbCl_(6) exhibit wide electrochemical windows and metastable properties(100 meV/atom>Ehull>0 meV/atom).However,the orthorhombic Li_(3)YbCl_(6) can be stabilized at high temperatures by taking the vibrational entropy into account,which is supported by the experimental ***,it is expected that because of the Yb/Li synergistic interactions that,due to their strong mutual coulomb repulsion,influence the Li^(+)transport behavior,the orthorhombic Li_(3)YbCl_(6) might have superior ionic conductivities with appropriate Li+migration paths determined by the Yb^(3+) ***,higher ionic conductivities can be obtained by regulating the random distribution of Li^(+) *** Li^(+)-deficiency can also largely increase the ionic conductivity by invoking *** study helps gain a deeper understanding of the laws that govern ionic conductivities and stabilities and provides a certain theoretical reference for the experimental development and design of halide solid-state electrolytes.

关键词： Halide solid-state electrolytes Phase stability Ionic conductivity First-principles calculations Rare earths

An approach of the internal friction-dependent temperature changes for conventional and pure biogenic lubricating greases

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Friction 2024年第4期12卷 780-795页

作者： Leif AHME Erik KUHN MiguelÁngel DELGADO Department of Mechanical Engineering and Production Management Hamburg University of Applied SciencesHamburg 20099Germany Department of Chemical Engineering Research in Product Technology and Chemical Processes(Pro2TecS)University of HuelvaHuelva 21071Spain

This work investigated the temperature changes inside the bulk of lubricating greases under controlled high-shear stress conditions(250-500 s-1).For this purpose,a newly developed temperature-measuring cell called Calidus was successfully *** temperature changes(ΔT)have been related to the greases'components(thickener,base oil-type,and composition)and the structural degradation of the lubricating ***,a theoretical approach was proposed for calculating the internal temperature change of lubricating greases during shear *** greases showed an internal temperature profile characterised by a sudden rise inΔT within the first 4 h from starting the test and subsequentΔT decay until it reaches the steady state ***,it was found that greases C1 and C5,formulated with lithium and calcium soap,respectively,with different soap content(16.1 wt%and 9.7 wt%,respectively),but the same base castor oil,showed the highest value of the maximumΔT,c.a.3.2 K,and the most drastic drop ofΔ*** greases showed both the highest specific densities and heat *** addition,they showed the lowest ratio of expended energies(Rtee),which means more structural degradation in the stressed *** the contrary,the grease C3,with 13 wt%of Li-soap but the lowest base oil's viscosity,showed the lowest maximumΔT and the temperature profile was characterised by a moderate variation ofΔT along the *** biogenic grease B3 developed a low-temperature change in the group of pure bio-genic greases close to grease C3.

关键词： shear-induced structural degradation rheology temperature measurements lubricating greases density lubricating greases specific heat capacities

Corrosion behavior of Al_(2)O_(3)-C bricks in MnO-containing mold slag

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Journal of Iron and Steel Research(International) 2024年第6期31卷 1486-1492页

作者： Yi-jiang Zhao Guang-qiang Li Yang Wu Cheng Yuan Ze Meng Xiao-xuan Deng Yu Liu The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081HubeiChina Hubei Provincial Key Laboratory for New processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan 430081HubeiChina Research Institute of Technology Shougang Group Co.Ltd.Beijing 100043China

In order to explore the corrosion mechanism of Al_(2)O_(3)-C refractories in the mold flux bearing MnO,the immersion test of Al_(2)O_(3)-C refractories in CaO-SiO2-CaF2-MnO slag with different MnO contents was carried out at 1550℃.The results show that Mn particles were observed in the slag after experiment,due to the reduction of MnO by graphite in *** amounts of graphite were observed at the interface between refractories and slag,indicating that the oxidation of graphite is limited by the poor contact between graphite and molten ***,the oxidation of graphite is not the main cause of damage to refractories.A small quantity of CaO·2Al_(2)O_(3)(CA_(2))and CaO·6Al_(2)O_(3)(CA_(6))adjacent to Al_(2)O_(3) grain was detected at the slag/reaction layer ***_(2) and CA_(6) possess relatively high melting points,which is beneficial to hindering the further penetration of ***,the dissolution of Al_(2)O_(3) into slag is still the main cause for refractories *** increase in the MnO content of mold slag decreases the viscosity and then results in the severe corrosion of Al_(2)O_(3)-C bricks.

关键词： Al_(2)O_(3)-C refractory MnO-containing slag Graphite Corrosion

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

Assembly and electrochemical testing of renewable carbon-based anodes in SIBs:A practical guide

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Journal of Energy Chemistry 2022年第12期75卷 457-477,I0012页

作者： Darío Alvira Daniel Antorán Joan JManyà Aragón Institute of Engineering Research(I3A) Thermochemical Processes GroupUniversity of ZaragozaEscuela Politécnica Superior22071 HuescaSpain

Sodium-ion batteries(SIBs)are considered as a promising candidate to replace lithium-ion batteries(LIBs)in large-scale energy storage *** sodium resources and similar working principles make this technology attractive to be implemented in the near ***,the development of high-performance carbon anodes is a focal point to the upcoming success of SIBs in terms of power density,cycling stability,and *** knowledge in electrochemical and physicochemical techniques is required to properly evaluate the anode performance and move it in the right *** review aims at providing a comprehensive guideline to help researchers from different backgrounds(e.g.,nanomaterials and thermochemistry)to delve into this *** main components,lab configurations,procedures,and working principles of SIBs are ***,a detailed description of the most used electrochemical and physicochemical techniques to characterize electrochemically active materials is provided.

关键词： Sodium-ion battery Anode Hard carbon Electrochemical techniques Carbon characterization