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Recent insights on iron based nanostructured electrocatalyst and current status of proton exchange membrane fuel cell for sustainable transport

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Journal of Energy Chemistry 2022年第6期31卷 466-489,I0013页

作者： mohamedazeem m.mohideen Adiyodi Veettil Radham.ni Seeram Ramakrishna Yen wei Yong Liu Beijing Key Laboratory of Advanced Functional Polymer Composites College of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029China Departm.nt of Physics and nanotechnology SRM Institute of Science and TechnologyKattankulathur 603203India Center for nanofibers and nanotechnology National University of SingaporeSingapore 1157Singapore Departm.nt of Chemistry Key Lab of Bioorganic Phosphorus Chemistry&Chemical BiologyTsinghua UniversityBeijing 100084China

Bridging the perform.nce gap of the electrocatalyst between the rotating disk electrode(RDE) and membrane electrode assembly(mEA) level testing is the key to reducing the total cost of proton exchange membrane fuel cell(PEmFC) vehicles. Presently, platinum metal accounts for ~42% of the total cost of the PEmFC vehicles for usage in the cathode catalyst layer, where the sluggish oxygen reduction reaction(ORR) occurs. An alternative to the platinum catalyst, the Fe-n-C catalyst has attracted considerable interest for PEmFC due to its cost-effectiveness and high catalytic activity towards ORR. However, the excellent ORR activity of Fe-n-C obtained from RDE studies rarely translates the same perform.nce into mEA operating conditions. Such a perform.nce gap is mainly attributed to the lack of atomic-level understanding of Fe-n-C active sites and their ORR mechanism. Besides, unless the cost of expensive electrocatalyst is reduced, the total operation cost of the PEmFC vehicles remains constant. Therefore,developing highly efficient Fe-n-C catalysts from academic and industrial perspectives is critical for commercializing PEmFC vehicles. Here, the scope of the review is three-fold. First, we discussed the atomiclevel insights of Fe-n-C active sites and ORR mechanism, followed by unraveling the different iron-based nanostructured ORR electrocatalysts, including oxide, carbide, nitride, phosphide, sulfide, and singleatom catalysts. And then we bridged their ORR catalytic perform.nce gap between the RDE and mEA tests for real operating conditions of PEmFC vehicles. Second, we focused on bridging the cost barriers of PEmFC vehicles between capital, operation, and end-user. Finally, we provided the path to achieve sustainable developm.nt goals by commercializing PEmFC vehicles for a better world.

关键词： Proton exchange membrane fuel cell(PEmFC) Active sites Iron-based nanostructure Sustainable developm.nt goals

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Applications of carbon nanomaterials in perovskite solar cells for solar energy conversion

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nano materials Science 2021年第3期3卷 276-290页

作者： Katherine moore wei wei Departm.nt of mechanical Engineering Wichita State University1845 Fairmount StWichitaKS67260USA

The energy issues and environm.ntal concern have led to intense research activities in renewable energy conversion,such as photovoltaic(PV)to convert solar energy into *** solar cells(PSCs)based on metal halides are rapidly emerging as the most promising and competing PV technology due to its high record power conversion efficiencies and potentially low production *** carbon materials,which are abundantly available and low-cost,are introduced into the *** article provides a m.ni review of applications of carbon materials for perovskite solar ***,a brief introduction of the developm.nt of perovskite solar cell is ***,applications of carbon nanomaterials in perovskite solar cells are presented and ***,an outlook and perspective on the future research directions of carbon nanomaterial for perovskite solar cells is provided.

关键词： Carbon nanomaterials Perovskite solar cells Solar energy

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Resolving the inner jet of PKS 1749+096 with super-resolution VLBA images at 7 mm

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Research in Astronomy and Astrophysics 2021年第4期21卷 202-206页

作者： Lang Cui Ru-Sen Lu wei Yu Jun Liu Victor m.Patino-Alvarez Qi Yuan Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210008China Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China max Planck Institute for Radio Astronomy Auf dem hiigel 69Bonn 53121Germany Instituto nacional de Astroffsica Optica y ElectronicaLuis Enrique Erro#1TonantzintlaPuebla 72840Mexico University of Chinese Academy of Sciences Beijing 100049China

High resolution imaging of inner jets in Active Galactic nuclei(AGns)with Very Long Baseline Interferometry(VLBI)at millimeter wavelengths provides deep insight into the launching and collimation mechanisms of relativistic *** BL Lac object,PKS 1749+096,shows a core-dom.nated jet pointing toward the northeast on parsec-scales revealed by various VLBI *** order to investigate the jet kinematics,in particular,the orientation of the inner jet on the smallest accessible scales and the basic physical conditions of the core,in this work we adopted a super-resolution technique,the Bi-Spectrum maximum Entropy method(BSmEm),to reanalyze VLBI images based on the Very Long Baseline Array(VLBA)observations of PKS 1749+096 within the VLBA-BU-BLAZAR 7 mm m.nitoring *** observations include a total of 105 epochs covering the period from 2009 to *** found that the stacked image of the inner jet is limb-brightened with an apparent opening angle of 50°.0±8°.0 and 42°.0±6°.0 at the distances of 0.2 and 0.3 mas(0.9 and 1.4 pc)from the core,corresponding to an intrinsic jet opening angle of 5°.2±1°.0 and 4°.3±0°.7,*** addition,our images show a clear jet position angle swing in PKS 1749+096 within the last ten *** discuss the possible implications of jet limb brightening and the connection of the position angle with jet peak flux density and gamma-ray brightness.

关键词： galaxies:quasars:individual:PKS 1749+096 galaxies:jets radio continuum:galaxies

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Wavelet analysis of stagnation point flow of non-newtonian nanofluid

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Applied mathematics and mechanics(English Edition) 2019年第8期40卷 1211-1226页

作者： m.HAmID m.USm.n R.U.HAQ4 Z.H.KHAn wei WAnG School of mathematical Sciences Peking UniversityBeijing 100871China BIC-ESAT College of EngineeringPeking UniversityBeijing 100871China State Key Laboratory for Turbulence and Complex Systems Department of Mechanics and Engineering SciencePeking UniversityBeijing 100871China Departm.nt of Electrical Engineering Bahria UniversityIslamabad 44000Pakistan State Key Laboratory of Hydraulics and mountain River Engineering College of Water Resource & HydropowerSichuan UniversityChengdu 610065China Key Laboratory of Advanced Reactor Engineering and Safety Ministry of Education Tsinghua UniversityBeijing 100084China

The wavelet approach is introduced to study the influence of the natural convection stagnation point flow of the Williamson fluid in the presence of thermophysical and Brownian motion effects. The thermal radiation effects are considered along a permeable stretching surface. The nonlinear problem is simulated numerically by using a novel algorithm based upon the Chebyshev wavelets. It is noticed that the velocity of the Williamson fluid increases for assisting flow cases while decreases for opposing flow cases when the unsteadiness and suction parameters increase, and the magnetic effect on the velocity increases for opposing flow cases while decreases for assisting flow cases. When the thermal radiation parameter, the Dufour number, and Williamson’s fluid parameter increase, the temperature increases for both assisting and opposing flow cases. meanwhile, the temperature decreases when the Prandtl number increases. The concentration decreases when the Soret parameter increases, while increases when the Schmidt number increases. It is perceived that the assisting force decreases more than the opposing force. The findings endorse the credibility of the proposed algorithm, and could be extended to other nonlinear problems with complex nature.

关键词： Williamson nanofluid heat and mass transfer stagnation point flow assisting and opposing flow Chebyshev wavelet method

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Adaptive Parameter Selection for Total Variation Image Deconvolution

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numerical mathematics(Theory,methods and Applications) 2009年第4期2卷 427-438页

作者： You-wei Wen Andy m. Yip Faculty of Science South China Agricultural University Guangzhou China Temasek Laboratories National University of Singapore 3 Science Drive 2 117543 Singapore Departm.nt of mathematics National University of Singapore 3 Science Drive 2 117543 Singapore

In this paper,we propose a discrepancy rule-based method to automatically choose the regularization parameters for total variation image restoration problems. The regularization parameters are adjusted dynamically in ... 详细信息

关键词： Image restoration regularization parameter total variation.

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Stabilization of nanoscale zero-valent iron in water with mesoporous carbon(n ZVI@mC)

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Journal of Environm.ntal Sciences 2019年第7期31卷 28-33页

作者： Junm.ng Shi Jing Wang wei Wang wei Teng wei-xian Zhang State Key Laboratory of Pollution Control and Resource Reuse School of Environmental Science and Engineering Tongji University School of Chemical Science and Engineering Tongji University

Two challenges persist in the applications of nanoscale zero-valent iron(nZVI) for environm.ntal remediation and waste treatm.nt: limited mobility due to rapid aggregation and short lifespan in water due to quick oxidation. Herein, we report the nZVI incorporated into mesoporous carbon(mC) to enhance stability in aqueous solution and mobility in porous media. meanwhile, the reactivity of nZVI is preserved thanks to high temperature treatm.nt and confinem.nt of carbon framework. Small-sized(～16 nm) nZVI nanoparticles are uniformly dispersed in the whole carbon frameworks. Importantly, the nanoparticles are partially trapped across the carbon walls with a portion exposed to the mesopore channels. This unique structure not only is conductive to hold the nZVI tightly to avoid aggregation during mobility but also provides accessible active sites for reactivity. This new type of nanomaterial contains ～10 wt% of iron. The nZVI@mC possesses a high surface area(～ 500 m^2/g) and uniform mesopores(～ 4.2 nm) for efficient pollutant diffusion and reactions. Also, high porosity of nZVI@mC contributes to the stability and mobility of nZVI. Laboratory column experim.nts further dem.nstrate that nZVI@mC suspension(～4 g Fe/L) can pass through sand columns much more efficiently than bare nZVI while the high reactivity of nZVI@mC is confirmed from reactions with ni(II). It exhibits remarkably better perform.nce in nickel(20 mg/L) extraction than mesoporous carbon, with 88.0% and 33.0%uptake in 5 m.n, respectively.

关键词： mesoporous carbon nanoscale zero-valent iron mobility Porous media Heavy metal removal

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Single-metal-atom site with high-spin state embedded in defective Bn nanosheet promotes electrocatalytic nitrogen reduction

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nano Research 2021年第11期14卷 4211-4219页

作者： Cong Fang wei An College of Chemistry and Chemical Engineering Shanghai University of Engineering ScienceShanghai201620China

Single-atom catalysts (SACs) especially supported on two-dim.nsional nitrogen-doped carbon substrate have been widely reported to be able to effectively promote electrocatalytic n_(2) reduction reaction (enRR). The precise design of single-metal-atom active site (SmAS) calls for fundam.ntal understanding of its working mechanism for enhanced enRR perform.nce. Herein, by means of density functional theory calculations, we theoretically investigate the enRR perform.nce of nine prototypical SmAS, namely, mn_(2)B_(2) (m: transition metals of IIIB, IVB and VB groups) which comprises of asymmetric ligands of n_(2)B_(2) embedded in defective Bn nanosheet. Our results reveal the significant role of spin state of SmAS in tuning the potential-determ.ning steps of enRR, in which mn_(2)B_(2) site with higher spin magnetic mom.nt (μ) is beneficial to reducing limiting potentials (U_(L)) of enRR. Specially, Crn_(2)B_(2) (μ = 4μB), Vn_(2)B_(2) (μ = 3μB) and m.n_(2)B_(2) (μ = 2μB) dem.nstrate high activity and selectivity to enRR. The asymmetric ligands of n_(2)B_(2) are deemed to be superior over m.no-symmetric ligands. more importantly, our results dem.nstrate that breaking (or deviating) of the scaling relations between key n-containing intermediates (*n_(2)H/*n_(2) and *nH2/*n_(2)) on mn_(2)B_(2) can be realized by enhancing spin state of SmAS which renders the active site a balanced n-affinity critical for efficient enRR. This observation is validated by the calculated Sabatier volcano-shape relation between enRR limiting potentials and n_(2) adsorption energy. Our study develops the guidance for catalyst design to boost enRR perform.nce by tuning the spin state of an active site.

关键词： electrocatalysis n_(2)reduction Bn nanosheet spin state single-atom catalyst jdensity functional theory(DFT)

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Preparation of cross-linked magnetic chitosan with quaternary amm.nium and its application for Cr(Ⅵ) and P(Ⅴ) removal

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Journal of Environm.ntal Sciences 2014年第12期26卷 2379-2386页

作者： wei Yao Pinhua Rao Irene m.C.Lo Wenqi Zhang Wenrui Zheng School of Chemistry and Chemical Engineering Shanghai University of Engineering Science Departm.nt of Civil and Environm.ntal Engineering The Hong Kong University of Science and Technology

Pollutants that exist in anionic species are issues of concern in water treatm.nt. Compared to cationic pollutants, the removal of anionic pollutants by adsorption is more difficult because most adsorbents carry predom.nantly negative charges in neutral and alkaline environm.nts. In this study, a cross-linked chitosan derivative with quaternary amm.nium and magnetic properties（Qm-chitosan） was prepared and employed to remove chromium（VI） and phosphorus（V）（Cr（VI） and P（V）） from aqueous environm.nts. The Qm-chitosan was characterized by Fourier transform infrared spectrometry（FT-IR）,thermogravimetric analysis（TGA）, energy dispersive X-ray（SEm-EDX） and zeta *** experim.nts show that Qm-chitosan can effectively remove Cr（VI） and P（V）, and the main mechanism was believed to be electrostatic interaction. A pseudosecond-order model was fitted to describe the kinetic processes of Cr（VI） and P（V） removal. The adsorption isotherms of both Cr（VI） and P（V） on the Qm-chitosan were well fitted by the Langmuir isotherm equation. The saturated adsorption capacity of P（V）（2.783 mmol/g） was found to be higher than that of Cr（VI）（2.323 mmol/g）, resulting from the size of the H2PO-4ions being smaller than that of the HCr O-4ions. However, the theoretical calculation and experim.ntal results showed that Qm-chitosan had a stronger affinity for Cr（VI） than P（V）. The adsorption–desorption of the Qm-chitosan was evaluated, and high regeneration rates were dem.nstrated.

关键词： magnetic chitosan Quaternary amm.nium Cr(VI) P(V) Adsorption

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Hot Deformation Behavior of an Ultra-High-Strength Fe–ni–Co-Based maraging Steel

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Acta metallurgica Sinica(English Letters) 2019年第9期32卷 1161-1172页

作者： Le Zhang wei Wang m. Babar Shahzad Yi-Yin Shan Ke Yang Institute of metal Research Chinese Academy of SciencesShenyang 110016China School of materials Science and Engineering University of Science and Technology of ChinaHefei 230026China Key Laboratory of nuclear materials and Safety Assessm.nt Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

Hot processing behavior of an ultra-high-strength Fe–ni–Co-based maraging steel was studied in temperature range of 900–1200℃and strain rate range of 0.001–10 s^-*** processing parameters and optimum hot working window were characterized via flow stress analysis,constitutive equation construction,hot processing map calculation and microstructure evolution,*** strain value for dynamic recrystallization was determ.ned through theoretical mathematical differential method:the inflection point ofθ–σand-αθ/ασ-σ*** was found that the flow stress increased with the decrease in deformation temperature and increase in the strain *** power dissipation maps in the strain range of 0.1–0.6 were entirely similar with the tendency of contour lines which implied that strain had no strong effect on the dissipation ***,the instability maps showed obvious strain sensitivity with increasing strain,which was ascribed to the flow localization and *** optimized hot processing window of the experim.ntal steel was obtained as 1100–1200℃/0.001–1 s^-1 and 1000–1100℃/0.001–0.1 s^-1,with the efficiency range of 20–40%.Owing to high mo content in the experim.ntal steel,high dynamic activation energy,Q=439.311 kJ mol^-1,was achieved,indicating that dynamic recrystallization was difficult to occur in the hot deformation process,which was proved via microstructure analysis under different hot deformation conditions.

关键词： maraging steel Hot working Dynamic recrystallization Constitutive equation Hot processing map

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circT P63-n suppresses the proliferation and metastasis of nasopharyngeal carcinoma via engaging with HSP90AB1 to modulate the YAP1/Hippo signaling pathway

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Science China Life Sciences 2025年

作者： Dan Wang Sicheng Zuo Junshang Ge Hongke Qu Jie Wu na Yi Lei Shi Yum.n Wang Yongzhen mo Chunmei Fan Yi He Pan Chen m.ng Zhou Bo Xiang wei Xiong Wenjia Guo Zhaoyang Zeng Can Guo nHC Key Laboratory of Carcinogenesis and Hunan Key Laboratory of Cancer metabolism Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine Central South University Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese m.nistry of Education Cancer Research Institute and School of Basic Medicine Sciences Central South University Furong Laboratory Cancer Research Institute Affiliated Cancer Hospital of Xinjiang Medical University Xinjiang Key Laboratory of Translational Biomedical Engineering

Circular RnAs(circRnAs) play pivotal roles in the developm.nt and progression of various diseases, including malignant tumors. However,the biological functions and the underlying mechanisms of m.ny circRnAs remain elusive. In this study, we identified a novel circRnA,circTP63-n, generated through the splicing of exons 2–4 of the TP63 gene in nasopharyngeal carcinoma(nPC). circTP63-n was found to be downregulated in clinical samples of nPC. Both in vitro and in vivo experim.nts unequivocally dem.nstrated that circTP63-n inhibits the proliferation and metastasis of nPC cells. Further investigations revealed that circTP63-n interacted with the HSP90AB1 protein, leading to the recruitm.nt of LATS/YAP1 proteins. This, in turn, induced phosphorylation and ubiquitination-dependent degradation of YAP1, resulting in reduced nuclear translocation of YAP1 and inhibition of the transcriptional activation of downstream oncogenic genes, including InHBA, mmP3, and CCnE2. Our findings highlight the identification of circTP63-n, a novel circRnA encoded by an important tumor-relevant gene TP63 and elucidate its molecular mechanism as a tumor suppressor in nPC. These insights offer novel potential molecular markers and therapeutic targets for the clinical diagnosis and treatm.nt of nPC.

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