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Atomically dispersed Fe sites on hierarchically porous carbon nanoplates for oxygen reduction reaction

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Journal of Energy Chemistry 2024年第3期90卷 7-15,I0002页

作者： Ruixue Zheng Qinglei Meng Hao Zhang Teng Li Di Yang Li Zhang Xiaolong Jia Changpeng Liu Jianbing Zhu Xiaozheng Duan Meiling Xiao Wei Xing State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022JilinChina School of applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026AnhuiChina Laboratory of Advanced Power Sources Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022JilinChina institute of Functional Nano&Soft Materials(FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials&DevicesJiangsu Key Laboratory of Advanced Negative Carbon TechnologiesSoochow UniversitySuzhou 215123JiangsuChina State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022JilinChina

Developing cost-effective,robust and stable non-precious metal catalysts for oxygen reduction reaction(ORR) is of paramount importance for electrochemical energy conversion devices such as fuel cells and metal-air *** Fe-N-C single atom catalysts(SACs) have been hailed as the most promising candidate due to the optimal binding strength of ORR intermediates on the Fe-N_(4) sites,they suffer from serious mass transport limitations as microporous templates/substrates,i.e.,zeolitic imidazolate frameworks(ZIFs),are usually employed to host the active *** by this challenge,we herein develop a hydrogen-bonded organic framework(HOF)-assisted pyrolysis strategy to construct hierarchical micro/mesoporous carbon nanoplates for the deposition of atomically dispersed Fe-N_(4) *** a design is accomplished by employing HOF nanoplates assembled from 2-aminoterephthalic acid(NH_(2)-BDC) and p-phenylenediamine(PDA) as both soft templates and C,N *** from the structural merits inherited from HOF templates,the optimized catalyst(denoted as Fe-N-C SAC-950) displays outstanding ORR activity with a high half-wave potential of 0.895 V(*** hydrogen electrode(RHE)) and a small overpotential of 356 mV at 10 mA cm^(-2) for the oxygen evolution reaction(OER).More excitingly,its application potential is further verified by delivering superb rechargeability and cycling stability with a nearly unfading charge-discharge gap of 0.72 V after 160 *** dynamics(MD) simulations reveal that micro/mesoporous structure is conducive to the rapid mass transfer of O_(2),thus enhancing the ORR *** situ Raman results further indicate that the conversion of O_(2) to~*O_(2)-the rate-determining step(RDS) for Fe-N-C *** work will provide a versatile strategy to construct single atom catalysts with desirable catalytic properties.

关键词： Fe single atom catalysts Oxygen reduction reaction Mesoporous structure Active sites Zinc-air battery

Strong anisotropy of thermal transport in the monolayer of a new puckered phase of PdSe

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Frontiers of physics 2024年第3期19卷 143-151页

作者： Zheng Shu Huifang Xu Hejin Yan Yongqing Cai Joint Key Laboratory of the Ministry of Education Institute of Applied Physics and Materials EngineeringUniversity of MacaoTaipaMacao 999078China

We examine the electronic and transport properties of a new phase PdSe monolayer with a puckered structure calculated by first-principles and Boltzmann transport *** spin−orbit coupling is found to play a negligible effect on the electronic properties of PdSe *** lattice thermal conductivity of PdSe monolayer exhibits remarkable anisotropic characteristic due to anisotropic phonon group velocity along different directions and its intrinsic structure *** compromised electronic mobility despite a relatively low thermal conduction results in a moderate ZT value but significantly anisotropic thermoelectric performance in single-layer *** present work suggests that the remarkable thermal transport anisotropy of PdSe monolayer can be used for thermal management,and enhance the scope of possibilities for heat flow manipulation in PdSe based *** sizeable puckered cages and wiggling lattice implies it an ideal platform for ionic and molecular engineering for thermoelectronic applications.

关键词： 2D materials first-principles calculations phonon

Regio-and Stereoselective Polymerization of Bio-based Ocimene by Rare-Earth Metal Catalysts

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Chinese Journal of Polymer Science 2024年第2期42卷 223-229,I0008页

作者： Qi-Yuan Wang Li-Peng Sang Zhen Zhang Yang Jiang Hui Tian Xia Zhao Xiang Guo Shi-Hui Li State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China School of applied Chemistry and Engineering University of Science and Technology of ChinaHefei230026China Science and Technology on Aerospace Chemical Power Laboratory Hubei Institute of Aerospace ChemotechonologyXiangyang441003China Shanxi Coal Chemical Industry Technology Research institute Xi’an710000China Hubei institute of Aerospace Chemotechonology Xiangyang441003China

Coordination polymerization of renewable β-ocimene has been investigated using asymmetric diiminophosphinate lutetium complex1, β-diketiminate yttrium complex 2, bis(phosphino)carbazolide yttrium complex 3, half-sandwich benzyl fluorenyl scandium complex 4 and pyridyl-methylene-fluorenyl rare-metal complexes 5a–5c. Complexes 1, 4 and 5a–5c show trans-1,2-regioselectivities and high activities, of which 5c exhibits excellent isoselectivity(mmmm>99%). Conversely, complexes 2 and 3 promote β-ocimene polymerization to produce isotactic cis-1,4-polyocimenes(cis-1,4>99%, mm>95%). Diblock copolymers cis-1,4-PIP-block-cis-1,4-POc and cis-1,4-PBD-block-cis-1,4-POc are obtained in one-pot reactions of β-ocimene with isoprene and butadiene using complex 3. Epoxidation and hydroxylation of polyocimene afford functionalized polyolefins with enhanced T_(g)(from-20 ℃ to 79 ℃ and 74 ℃) and hydrophilicity.

关键词： Biobased monomer Terpenes Ocimene Rare-earths Polymerization Regio/stereoselectivity Elastomer

Regulation of the multi-emission centers in carbon dots via a bottom-up synthesis approach

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Chinese Chemical Letters 2024年第9期35卷 238-242页

作者： Bohan Zhang Bingzhe Wang Guichuan Xing Zikang Tang Songnan Qu Joint Key Laboratory of the Ministry of Education Institute of Applied Physics and Materials EngineeringUniversity of MacaoMacao 999078China

Understanding the luminescence mechanisms and regulating the emission centers of carbon dots(CDs)are important for advancing their related *** this work,we systematically investigate the formation processes of multi-emission centers in CDs synthesized through a bottom-up approach by controlling the solvothermal reaction *** synthesized at a lower temperature(140℃,140-CDs)exhibit smaller particle sizes(3–4 nm)with dominant green–yellow emission,while CDs synthesized at a higher temperature(180℃,180-CDs)exhibit larger particle sizes(8–9 nm)with enhanced red emission and emerging near-infrared(NIR)*** green–yellow emission and red emission originate from the core state and the surface-related state,respectively,and the emissions could be regulated by temperature-controlled dehydration and carbonization *** clear NIR emission center in 180-CDs is attributable to the increased content of radical defects in the cores during the increased dehydration and carbonization processes during higher-temperature solvothermal treatment.

关键词： Carbon dot Photoluminescence Defect state Core state Temperature regulation

Efficient enrichment and selective recovery of rare earths from sulfate leachate of ion-adsorption type rare earth ore by extraction with HPOAc

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Journal of Rare Earths 2024年第11期42卷 2156-2165页

作者： Jinglu Han Yanling Li Songsong Li Wuping Liao State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of Sciences School of applied Chemistry and Engineering University of Science and Technology of China Ganjiang Innovation Academy Chinese Academy of Sciences

The efficient enrichment and separation of rare earth elements（REEs） from sulfate leachates of ionadsorption type rare earth ore（IATREO） is still a *** work presents a novel extractant 2-(bis(（2-ethylhexyl）oxy)phosphoryl)-2-hydroxyacetic acid（HPOAc） for the selective extraction and efficie nt enrichment of REEs from sulfate leachates of *** exhibits higher extraction ability for all fifteen REEs（Ⅲ） than naphthenic acid（NA） at pHini=1,***,it has no drawbacks of di-（2-ethylhexyl） phosphoric acid（P204） and 2-ethylhexyl phosphoric acid mono-2-ethylhexylester（P507）such as weak extraction ability towards light REEs（Ⅲ） and high stripping acidity for heavy REEs（Ⅲ）.It has better separation performance for metal ion impurities than P204 and P507,especially for the typical impurity Al（Ⅲ）.Furthermore,the HPOAc system has better phase separation behavior and extraction pheno mena.A simulated operation with two-stage counte r-current extraction and single-stage stripping of REEs was carried out using unsaponified *** recovery of REEs reaches 98.7%.The concentration of REEs increases from 0.44 to 130.35 g/L,indicating a nearly 300-fold ***,the content of REEs increases from 77.8 wt% to 97.6 wt%.So HPOAc has the potential to selectively recover REEs from sulfate leachates of IATREO.

关键词： Enrichment Extractants Rare earths Separation Solvent extraction

Direct visualization of laser-driven dynamic fragmentation in tin by in situ x-ray diffraction

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Matter and Radiation at Extremes 2024年第5期9卷 109-114页

作者： Jing Yang Xinxin Wang Liang Xu Qiannan Wang Yi Sun Jiangtao Li Lin Zhang Yinghua Li Yuying Yu Pei Wang Qiang Wu Jianbo Hu Laboratory for Shock Wave and Detonation Physics Institute of Fluid PhysicsChina Academy of Engineering PhysicsMianyang 621900China Laboratory of Computational Physics Institute of Applied Physics and Computational MathematicsBeijing 100094China

We present a novel method for investigating laser-driven dynamic fragmentation in tin using in situ X-ray *** experimental results demonstrate the feasibility of the method for simultaneously identifying the phase and temperature of fragments through analysis of the diffraction ***,we observe a deviation from the widely accepted isentropic release assumption,with the temperature of the fragments being found to be more than 100 K higher than expected,owing to the release of plastic work during dynamic *** findings are further verified through extensive large-scale molecular dynamics simulations,in which strain energies are found to be transferred into thermal energies during the nucleation and growth of voids,leading to an increase in *** findings thus provide crucial insights into the impact-driven dynamic fragmentation phenomenon and reveal the significant influence of plastic work on material response during shock release.

关键词： dynamic release diffraction

Amphipathic Janus Nanofibers Aerogel for Efficient Solar Steam Generation

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Energy & Environmental Materials 2024年第4期7卷 422-432页

作者： Rui Wang Jinshuo Deng Ping Wu Qianli Ma Xiangting Dong Wensheng Yu Guixia Liu Jinxian Wang Lei Liu Chongqing Research institute Changchun University of Science and Technology Key Laboratory of applied Chemistry and Nanotechnology at Universities of Jilin Province Changchun University of Science and Technology

Solar steam generation is a promising water purification technology due to its low-cost and environmentally friendly applications in water purification and ***,hydrophilic or hydrophobic materials alone are insufficient in achieving necessary characteristics for constructing highquality solar steam generators with good comprehensive properties.

关键词： aerogels electrospinning photothermal materials solar desalination solar steam generation

Flow instability of supercritical hydrocarbon fuel in a multi-channel cooling system

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Chinese Journal of Aeronautics 2024年第2期37卷 283-295页

作者： Yichao JIN Kun WU Xuejun FAN institute of applied Physics and Computational Mathematics Beijing 100094China institute of Mechanics Chinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China

Thermally-induced flow instabilities are a critical issue in multi-channel regenerative cooling *** particular,the interactions between Density-Wave Oscillations(DWO)and Flow Maldistribution(FMD)can result in complex and disastrous instability *** study investigates the instability behaviors of hydrocarbon fluid in a four-channel system with a constant heat flux ratio using both frequency-and time-domain *** the heat flux increases,the in-tube flow sequentially destabilizes in each channel and converges to new equilibrium states,leading to the emergence of FMD *** also causes the system eigenvalue to change repeatedly from negative to positive rather than increasing ***,the system eigenvalues are between those of the two most unstable channels,indicating that the stability behavior of the entire system is dictated by the most unstable *** FMD occurs,flow oscillations are activated in channels with weak stability,and the in-tube flow is observed to evolve into various flow patterns,including stable flow,self-sustained oscillation,oscillation divergence,quasiperiodic oscillation,and oscillation *** novel instability mode of oscillation excursion involves a spontaneous transition of operating *** oscillates from an equilibrium state and then stabilizes at a new operational state after oscillation-induced ***,the newfound stable state may also be only temporary,with the in-tube flow regressing to the initial state,resulting in quasi-periodic oscillation.

关键词： Cooling Supercritical fluids Hydrocarbons Flow instability Flow maldistribution Density-wave oscillations

Free-standing microscale photonic lantern spatial mode(De-)multiplexer fabricated using 3D nanoprinting

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Light(Science & Applications) 2024年第6期13卷 1170-1185页

作者： Yoav Dana Yehudit Garcia Aleksei Kukin Lauren Dallachiesa Sterenn Guerrier Nicolas K.Fontaine Dan M.Marom institute of applied Physics Hebrew University of JerusalemJerusalemIsrael Nokia Bell Labs 600 Mountain AveNew ProvidenceNJ07974USA

Photonic lantern(PL)spatial multiplexers show great promise for a range of applications,such as future high-capacity mode division multiplexing(MDM)optical communication networks and free-space optical *** enable efficient conversion between multiple single-mode(SM)sources and a multimode(MM)waveguide of the same *** multiplexers operate by facilitating adiabatic transitions between the SM arrayed space and the single MM ***,current fabrication methods are forcing the size of these devices to multi-millimeters,making integration with micro-scale photonic systems quite *** advent of 3D micro and nano printing techniques enables the fabrication of freestanding photonic structures with a high refractive index contrast(photopolymer-air).In this work we present the design,fabrication,and characterization of a 6-mode mixing,375µm long PL that enables the conversion between six single-mode inputs and a single six-mode *** PL was designed using a genetic algorithm based inverse design approach and fabricated directly on a 7-core fiber using a commercial two-photon polymerization-based 3D printer and a *** the waveguides exhibit high index contrast,low insertion loss(−2.6 dB),polarization dependent(−0.2 dB)and mode dependent loss(−4.4 dB)were measured.

关键词： mode enable printing