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Early-stage latent thermal failure of single-crystal Ni-rich layered cathode

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Journal of Energy Chemistry 2024年第9期96卷 578-587页

作者： Xiao Han Ruoyu Xu Yan Li Yang Ding Manchen Zhang Bo Wang Xiaoxing Ke Manling Sui Pengfei Yan Beijing Key Laboratory of Microstructure and Property of Solids Faculty of Materials and ManufacturingBeijing University of TechnologyBeijing 100124China Watt Laboratory Central Research InstituteHuawei Technologies Co.LTDShenzhen 518129GuangdongChina

High nickel co.tent worsens the thermal stability of layered cathodes for lithium-ion batteries,raising safety co.cerns for their *** understanding the thermal failure process can offer valuable guidance for material optimization on thermal stability and new opportunities in monitoring battery thermal runaway(TR).Herein,this work co.prehensively investigates the thermal failure process of a single-crystal nickel-rich layered cathode and finds that the latent thermal failure starts at∼120℃far below the TR temperature(225℃).During this stage of heat accumulation,sequential structure transition is revealed by atomic resolution electron microsco.y,which follows the layered→cation mixing layered→LiMn_(2)O_(4)-type spinel→disordered spinel→rock *** progression occurs as a result of the continuous migration and densification of transition metal *** transition generates gaseous oxygen,initially co.fined within the isolated closed pores,thereby not showing any thermal failure phenomena at the *** temperature leads to pore growth and co.lescence,and eventually to the formation of open pores,causing oxygen gas release and weight loss,which are the typical TR *** highlight that latent thermal instability occurs before the macro-level TR,suggesting that suppressing phase transitions caused by early thermal instability is a crucial direction for material *** findings can also be used for early warning of battery thermal runaway.

关键词： Thermal runaway Nickel-rich layered cathode Transmission electron microsco.y Lithium-ion battery Phase transition

Photon co.nting technique as a potential tool in micro-defect detection of epoxy insulation pull rod in gas-insulated switchgears

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High Voltage 2024年第2期9卷 267-274页

作者： Xianhao Fan Shu Niu Hanhua Luo Jizhong Liang Fang Liu Wenqiang Li Weidong Liu Wensheng Gao Yulong Huang Chuanyang Li Jinliang He School of Electrical Engineering Tsinghua UniversityBeijingChina Electric Power Research Institute Shangxi Power Grid CorporationTaiyuanShanxiChina Shandong Taikai Electrical Insulation co. Ltd.TaianShandongChina

The micro-defects in epoxy-based insulation materials generate a local high electric field which results in continuous degradation,seriously endangering the insulation system of gas-insulated switchgears.A highly sensitive detection technique is reported for micro-defects of insulation pull rods based on the photon co.nting(PC)*** re-sults demonstrated that for an epoxy-based insulation pull rod,the photons released during electroluminescence and ionisation at 2 kV,which is less than the partial discharge inception voltage,can be clearly *** findings presented a strong co.relation between photon co.nts and defect *** has been co.ducted to elucidate the mechanism behind defect-induced PC,employing the amplification of ionising luminescence through electric field distortion induced by micro defects and the augmentation of electroluminescence through the aggregation of trap *** this regard,the authors verified that PC can serve as a potential tool in the detection of micro-insulation defects,which also has huge potential in online insulation co.dition monitoring.

关键词： technique. insulation defect

Dynamic characteristics and application of dual throat fluidic thrust vectoring nozzle

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Chinese Journal of Aeronautics 2024年第9期37卷 85-99页

作者： Buxian XU Dongping HU Lihao FENG Fluid Mechanics Key Laboratory of Ministry of Education Beihang UniversityBeijing 100191China State Key Laboratory of Clean and Efficient Turbomachinery Power Equipment Dongfang Electric Corporation Dongfang Turbine Co.LTDDeyang 618000China

Thrust vectoring technology plays an important role in improving the maneuverability of *** order to overco.e the disadvantages of mechanical thrust vectoring nozzles,such as co.plications of structure and significant increases in weight and co.t,fluidic thrust vectoring noz-zles are *** Throat fluidic thrust vectoring Nozzle(DTN)has received wide attention due to its excellent thrust vectoring efficiency and minimal thrust *** this study,three-dimensional unsteady numerical simulations of a single axisymmetric DTN are co.ducted first to analyze its dynamic *** the pitch and yaw co.trol characteristics of DTN equipped on a flying-wing aircraft are *** is found that the dynamic response will experience three stages:rapid-deflecting stage,oscillating stage,and steady stage.A co.plete recirculation zone forms at the end of the rapid-deflecting stage,which pushes the primary flow to attach to the wall opposite the seco.dary ***,the exhaust flow is *** terms of DTN's appli-cation,the DTN equipped on the flying-wing aircraft is capable of providing effective pitch and yaw moments at all angles of attack and Mach *** addition,continuous pitch and yaw moments can be obtained by adjusting the seco.dary mass flow *** co.trol moment is gen-erated due to the asymmetrical pressure distribution of nozzle surface,which is mainly co.tributed by the pressure decrease on the seco.dary injection ***,the DTN equipped on the flying-wing aircraft has a relatively high thrust vectoring efficiency of around 5°/%and a thrust co.fficient of around 0.95 when nozzle pressure ratio equals *** results provide an important theoretical basis for the practical application of DTN.

关键词： Dual throat nozzle Dynamic response charac-teristic Flowco.trol Flying-wing aircraft

Reduced magma generation and its implications for the Pulang giant porphyry Cu-polymetallic deposit in Northwest Yunnan,China

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Acta Geochimica 2024年第4期43卷 802-813页

作者： Jingwei Guan Tao Ren Lei Wang Shenjin Guan Lianrong Wu Baosheng Shi Faculty of Land Resources Engineering Kunming University of Science and TechnologyKunming 650093People’s Republic of China Diqing Nonferrous Metals co. LtdShangri-La 674400People’s Republic of China

The Pulang giant porphyry Cu-Mo polymetallic deposit is located in the Zhongdian area in the center of the Sanjiang Tethys tectonic domain,which was formed by the westward subduction of the Garze-Litang oceanic slab beneath the Zhongza ***-pyrrhotite-pyritemolybdenite occurs as disseminations,veins,veinlets,and stockworks distributed in the K-silicate alteration zone in the monzonite porphyry,which is superimposed by *** chemical co.positions of biotite and amphibole analyzed by electron probe microanalysis(EPMA)indicate that the ore-forming magma and exsolved fluids experienced a continuous decrease in the oxygen fugacity(fO_(2)).Primary amphibolite and biotite(type I)crystallized at relatively high temperatures(744-827°C)and low fO_(2)(log fO_(2)=−12.26 to−11.91)during the magmatic *** fluids exsolved from the magma have a relatively lower temperature(621-711°C)and fO_(2)(log fO_(2)=−14.36 to−13.32)than the original *** addition,the presence of a high abundance of pyrrhotite and an insufficiency of primary magnetite and sulfate in the ore(i.e.,anhydrite and gypsum)indicate that the deposit may be a reduced porphyry *** and fluid fO_(2)results,co.bined with previous research on magmatic fO_(2)at the Pulang deposit,indicate that the magma associated with the reduced Pulang ore assemblages was initially generated as a highly oxidized magma that was subsequently reduced by sedimentary rocks of the Tumugou Formation.

关键词： Porphyry deposit Oxygen fugacity(fO_(2)) co.tamination of surrounding rock Pulang Zhongdian arc

Risk assessment,fitness co.t,cross-resistance,and mechanism of tetraniliprole resistance in the rice stem borer,Chilo suppressalis

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Insect Science 2024年第3期31卷 835-846页

作者： Hao Sun Shuai Wang Chong Liu Wen-Kai Hu Jin-Wei Liu Ling-Jun Zheng Meng-Yue Gao Fang-Rui Guo Song-Tao Qiao Jun-Li Liu Bo Sun co.g-Fen Gao Shun-Fan Wu co.lege of Plant Protection Nanjing Agricultural UniversityState&Local Joint Engineering Research Center of Green Pesticide Invention and ApplicationNanjingChina Bayer Cropscience(China)co. Ltd.HangzhouChina

The rice stem borer(RSB),Chilo suppressalis,a notorious rice pest in China,has evolved a high resistance level to co.monly used ***,a new anthranilic diamide insecticide,effectively co.trols multiple pests,including ***,the potential resistance risk of RSB to tetraniliprole is still *** this study,the tetraniliprole-selection(Tet-R)strain was obtained through 10 continuous generations of selection with tetraniliprole 30%lethal co.centration(LC_(30)).The realized heritability(h^(2))of the Tet-R strain was 0.387,indicating that resistance of RSB to tetraniliprole developed rapidly under the continuous selection of *** Tet-R strain had a high fitness co.t(relative fitness=0.53).We established the susceptibility baseline of RSB to tetraniliprole(lethal co.centration at LC_(50)=0.727 mg/L)and investigated the resistance level of 6 field populations to *** tested strains that had resistance to chlorantraniliprole exhibited moderate-to high-level resistance to tetraniliprole(resistance ratio=27.7-806.8).Detection of ryanodine receptor(RyR)mutations showed that the Y4667C,Y4667D,I4758M,and Y4891F mutations were present in tested RSB field *** mutations were responsible for the cross-resistance between tetraniliprole and ***,the clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated protein 9-mediated genome-modified flies were used to study the co.tribution of RyR mutations to tetraniliprole *** order of co.tribution of a single RyR mutation to tetraniliprole resistance was Y4667D>G4915E>Y4667C~~I4758M>*** addition,the I4758M and Y4667C double mutations co.ferred higher tetraniliprole resistance than single Y4667C *** results can guide resistance management practices for diamides in RSB and other arthropods.

关键词： Chilo suppressalis diamide resistance fitness co.t cross-resistance RyR target-site mutations

Quantificational indexes for design and evaluation of co.per staves for blast furnaces

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Journal of University of Science and Technology Beijing 2008年第1期15卷 10-16页

作者： Liang Qian Susen Cheng Hongbo Zhao School of Metallurgical and Eco.ogical Engineering University of Science and Technology Beijing Beijing 100083 China continuous casting Technology Engineering co. Ltd. MCC Group Beijing 100081 China

The quantificational and normative design is the preco.dition of improving the design of co.per staves for blast furnaces. Based on a 3-dimensional temperature field calculation model, from the view point of heat transfer and long campaigns note with the co.e of forming accretion, the forming-accretion-ability （FAA） and the rib hot surface maximum temperature difference （ATmax） as quantificational indexes to direct and evaluate the design of co.per staves for blast furnaces were presented. The application of the two indexes in design essentially embodies the new long campaigns in the stage of design. With the application of the two indexes, good results can be obtained. Firstly, it was suggested that the rib height of a co.per stave can be reduced to 15 mm, which is a new method and theory for the reduction of co.per staves. Seco.dly, the influence of insert on FAA and ATmax, is decided by the volume of insert. Acco.ding to this, the principle of design for the hot surface geometry of co.per staves was put forward that the ratio of the rib hot surface to the co.per stave hot surface （abbreviated as the ratio of rib to stave） must be maintained in the range of 45% to 55%; for the present co.per stave with a 35-40 mm thick rib, the ratio of rib to stave in the range of 50% to 55% can optimize the design of co.per staves; for the co.per stave with a smaller rib thickness, for example 15 ram, the ratio of rib to stave in the range of 45% to 50% can optimize the design of co.per staves. It can be summarized that the thicker the rib thickness, the larger is the ratio of rib to stave. 2008 University of Science and Technology Beijing. All rights reserved.

关键词： blast furnace (BF) co.per stave quantificational index forming-accretion-ability

Boundary slip and lubrication mechanisms of organic friction modifiers with effect of surface moisture

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Friction 2024年第7期12卷 1483-1498页

作者： Xiaobin YI Haiyu XU Ge JIN Yang LU Biqiang CHEN Shaofeng XU Junqin SHI Xiaoli FAN State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsNorthwestern Polytechnical UniversityXi’an 710072China Xi’an Thermal Power Research Institute co. Ltd.Xi’an 710054China NingboTech University Ningbo 315000China

Surface moisture or humidity impacting the lubrication property is a ubiquitous phenomenon in tribological systems,which is demonstrated by a co.bination of molecular dynamics(MD)simulation and experiment for the organic friction modifier(OFM)-co.taining *** stearic acid and poly-α-olefin 4cSt(PAO4)were chosen as the OFM and base oil molecules,*** physical adsorption indicates that on the moist surface water molecules are preferentially adsorbed on friction surface,and even make OFM adsorption film thoroughly leave surface and mix with base *** shear process,the adsorption of water film and desorption OFM film are further enhanced,particularly under higher shear *** simulated friction co.fficient(that is proportional to shear rate)increases firstly and then decreases with thickening water film,in good agreement with experiments,while the slip length shows a co.trary *** wear increases with humidity due to tribochemistry revealing the continuous formation and removal of Si–O–Si *** tribological discrepancy of OFM-co.taining lubricant in dry and humid co.ditions is attributed to the slip plane’s transformation from the interface between OFM adsorption film and lubricant bulk to the interface between adsorbed water *** work provides a new thought to understand the boundary lubrication and failure of lubricant in humid environments,likely water is not always harmful in oil lubrication systems.

关键词： organic friction modifier(OFM) boundary lubrication boundary slip surface moisture

Oxidation behavior of 4774DD1 Ni-based single-crystal superalloy at 980℃ in air

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China Foundry 2024年第2期21卷 116-124页

作者： Yu Fang Ya-zhou Li Qiang Yang Qun-gong He Xiu-fang Gong Qian Duan Hai-yang Song Fu Wang Qiong-yuan Zhang Hong Zeng State Key Laboratory of Long-Life High Temperature Materials Dongfang Turbine Co.Ltd.Deyang 618000SichuanChina State Key Laboratory for Manufacturing System Engineering School of Mechanical EngineeringXi’an Jiaotong UniversityXi’an 710049China

The oxidation behavior of a novel Ni-based single-crystal 4774DD1 superalloy for industrial gas turbine applications was investigated by the isothermal oxidation at 980℃ and discontinuous oxidation weight gain *** phase co.stitution and morphology of surface oxides and the characteristics of the crosssection oxide film were analyzed by XRD,SEM and *** show that the oxidation kinetics of the 4774DD1 superalloy follows the cubic law,indicating its weak oxidation resistance at this *** the oxidation time increases,the co.position of the oxide film evolves as following:One layer co.sisting of a bottom Al_(2)O_(3)sublayer and an upper(Al_(2)O_(3)+NiO)mixture sublayer after oxidized for 25 ***,two layers co.posed of an outermost small NiO discontinuous grain layer and an internal layer for 75 *** internal layer is co.sisted of the bottom Al_(2)O_(3)sublayer,an intermediate narrow CrTaO_(4)sublayer,and an upper(Al_(2)O_(3)+NiO)mixture *** two layers co.prising an outermost relative continuous NiO layer with large grain size and an internal layer as the oxidation time increases to 125 *** internal layer is co.posed of the upper(Al_(2)O_(3)+NiO)mixture sublayer,an intermediate continuous(CrTaO_(4)+NiWO_(4))mixture sublayer,and a bottom Al_(2)O_(3)***,three layers co.sisting of an outermost(NiAl2O_(4)+NiCr2O_(4))mixture layer,an intermediate(CrTaO_(4)+NiWO_(4))mixture layer,and a bottom Al_(2)O_(3)layer for 200 h.

关键词： nickel-base single crystal superalloy oxidation kinetics oxide film microstructure mechanism

Fluorinated semi-interpenetrating polymer networks for enhancing the mechanical performance and storage stability of polymer-bonded explosives by co.trolling curing and phase separation rates

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Defence Technology（防务技术） 2024年第8期38卷 58-66页

作者： Chao Deng Huihui Liu Yongping Bai Zhen Hu School of Chemistry and Chemical Engineering Harbin Institute of TechnologyHarbin 150000China Wuxi HIT New Material Research Institute co. Ltd.Wuxi 214000China Institute of Chemical Materials China Academy of Engineering PhysicsMianyang 621900China

Herein, the effect of fluoropolymer binders on the properties of polymer-bonded explosives(PBXs) was co.prehensively investigated. To this end, fluorinated semi-interpenetrating polymer networks(semiIPNs) were prepared using different catalyst amounts(denoted as F23-CLF-30-D). The involved curing and phase separation processes were monitored using Fourier-transform infrared spectrosco.y, differential scanning calorimetry, a haze meter and a rheometer. Curing rate co.stant and activation energy were calculated using a theoretical model and numerical method, respectively. Results revealed that owing to its co.continuous micro-phase separation structure, the F23-CLF-30-D3 semi-IPN exhibited co.siderably higher tensile strength and elongation at break than pure fluororubber F2314 and the F23-CLF-30-D0 semi-IPN because the phase separation and curing rates matched in the initial stage of *** arc Brazilian test revealed that F23-CLF-30-D-based co.posites used as mock materials for PBXs exhibited excellent mechanical performance and storage stability. Thus, the matched curing and phase separation rates play a crucial role during the fabrication of high-performance semi-IPNs;these factors can be feasibly co.trolled using an appropriate catalyst amount.

关键词： Semi-interpenetrating polymer networks Fluoropolymer Curing rate Phase separation rate Polymer-bonded explosives