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Oxygen vacancy-rich amorphous FeNi hydroxide nanoclusters as an efficient electrocatalyst for water oxidation

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Journal of Energy Chemistry 2022年第8期31卷 167-173,I0005页

作者： Youhai Cao yang Su Liangliang Xu xiaohua yang Zhongkang Han Rui Cao Gao Li State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina Institute of Quantum and Sustainable Technology(IQST) School of Chemistry and Chemical EngineeringJiangsu UniversityZhenjiang 212013JiangsuChina Multidisciplinary Computational Laboratory Department of Electrical and Biomedical EngineeringHanyang UniversitySeoul 04763South Korea Center for Energy Science and Technology Skolkovo Institute of Science and TechnologySkolkovo Innovation CenterMoscow 143026Russia Stanford Synchrotron Radiation Lightsource SLAC National Accelerator LaboratoryMenlo ParkCA 94025USA

In this work,a one-pot strategy is presented to directly synthesize amorphous Fe_(x)Ni_(y) hydroxide nanoclusters(denoted as ANC-Fe_(x)Ni_(y),<2 nm)with oxygen vacancies induced by ionic *** ANC-Fe_(x)Ni_(y) catalyst presents abundant catalytic sites and high intrinsic *** such,the optimized ANC-Fe_(1)Ni_(2) exhibits high activity in oxygen evolution reaction(OER)with a Tafel slope of 39 m V dec^(–1) and an overpotential of 266 m V at 10 m A cm^(-2).Notably,the optimized ANC-Fe_(1)Ni_(2) shows an extraordinarily large mass activity of 3028 Ag_(FeNi)^(–1) at the overpotential of 300 m V,which is~24-fold of commercial RuO_(2) *** superior activity of these Fe_(x)Ni_(y) hydroxide nanoclusters is ascribed to(i)the amorphous and distorted structure with abundant oxygen vacancies,and(ii)enhanced active site density by downsizing the *** strategy provides a novel route for enhancing OER electrocatalytic performance and highly encouraging for the future application of amorphous metal hydroxides in catalysis.

关键词： Oxygen evolution reaction Hydroxides Amorphous Ni-Fe based nanoclusters Ionic liquids Oxygen vacancies

Statistical analysis of one Chinese sun-synchronous satellite anomalies

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Science China(Technological Sciences) 2016年第4期59卷 540-546页

作者： TIAN Tian ZONG QiuGang CHANG Zheng WANG YongFu yang xiaohua Institute of Space Physics and Applied Technology Peking UniversityBeijing 100871China Mailbox 5111 Beijing 100094China Center for Space Science and Applied Research Chinese Academy of SciencesBeijing 100190China

Based on the data from the Medium-Energy Proton and Electron Detector （MEPED） onboard NOAA-17, 141 anomalies of a Chinese Sun-Synchronous satellite （SSO-X） that occurred between 02/01/2010 and 09/31/2012 were studied statistically. About 26 out of the 52 anomalies that occurred outside the South Atlantic Anomaly （SAA） were accompanied by energetic electron storms. Superposed Epoch Analysis （SEA） was used to analyze the properties of the anomalies and the dynamics of the space environments during these 26 events. Then, a Monte Carlo method was utilized to simulate the electron deposition and the interactions of the injected electrons with an aluminum shield and polyethylene dielectric. The average, median, and 75tb percentile values of the maximum electric field strength inside the dielectric were calculated. The results showed the tbl- lowing. （1） SSO-X anomalies are more likely to occur within the SAA, as 89 out of 141 anomalies （63%） occurred there. （2） Twenty-six of the anomalies that occurred outside the SAA during energetic electron storms were located near the outer boundaries of the outer radiation belts, and these were more frequent in the Southern Hemisphere than in the Northern Hemi- sphere. （3） Electron flux enhancements occurred around the failure time at all energy levels but were more profound in the lower energy channels. The maximum fluxes of electrons 〉30 keV, 〉100 keV, and 〉300 keV were 106, 3.5x10s, and 1.2×10^6 cm 2 s^-1 · sr ^-1, respectively. （4） The average, median, and 75th percentile values of the maximum electric field strengths inside the dielectric for the aforementioned 26 events remained in the range from 106 to 107 V/m for long time periods, which sug- gests that the ＇potential hazards＇ of internal discharges cause SSO-X anomalies. The above results can provide useful infor- mation for the design and protection of sun-synchronous spacecraft.

关键词： SSO-X failure superposed epoch analysis Monte Carlo method internal charging maximum electric field strength radiation belts

The degradation of cathodic Fe/N/C catalyst in PEMFCs:The evolution of remanent active sites after demetallation

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Journal of Materials Science & Technology 2024年第6期173卷 100-106页

作者： xiaohua yang Wentao Sun Jiatang Chen yang Gao Rongxian Zhang Qun Luo Tao Lyu Lei Du Institut National de la Recherche Scientifique-Énergie Matériaux et Télécommunications J3X 1P7 VarennesQCCanada School of Chemistry and Chemical Engineering Jiangsu UniversityZhenjiang 212013China State Key Laboratory of Advanced Special Steels&Shanghai Key Laboratory of Advanced Ferrometallurgy School of Materials Science and EngineeringShanghai UniversityShanghai 200444China Huangpu Hydrogen Energy Innovation Center School of Chemistry and Chemical EngineeringGuangzhou UniversityGuangzhou 510006China

The state-of-the-art Fe/N/C catalyst has presented comparable initial cathode performance to the benchmark Pt/C catalyst in proton exchange membrane fuel cells(PEMFCs).However,the major bottleneck is its significant activity decay in real-world PEMFC *** superposed“fast decay”and“slow decay”have been well documented to describe the degradation process of Fe/N/C catalysts during PEMFC *** fast decay has been well understood in close relation to the demetallation at the initial 15-h stability ***,it is still unclear how the remanent active sites evolve after *** this end,the catalyst performance and evolution of a typical Fe/N/C active site were herein investigated through postmortem characterizations of the membrane electrode assemblies(MEAs)after different *** is presented that 1 bar pressure and 80℃ temperature are the optimized conditions for Fe/N/C ***,the“fast decay”in the initial 15 h is immune to the various operating parameters,while the“slow decay”highly depends on the applied temperature and *** to the X-ray absorption spectra(XAS)analysis and stability test of MEA,the gradual evolution of Fe-N coordination to Fe-O is found correlated with the“slow decay”and accounts for the catalyst decay after the demetallation process.

关键词： Fe/N/C Stability Decay mechanism Metal oxidation PEMFCs

Spatiotemporal Variations of Meteorological Droughts in China During 1961–2014: An Investigation Based on Multi-Threshold Identification

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International Journal of Disaster Risk Science 2016年第1期7卷 63-76页

作者： Jun He xiaohua yang Zhe Li Xuejun Zhang Qiuhong Tang Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences School of Environment Beijing Normal University University of Chinese Academy of Sciences

As a major agricultural country, China suffers from severe meteorological drought almost every *** studies have applied a single threshold to identify the onset of drought events, which may cause problems to adequately characterize long-term patterns of *** study analyzes meteorological droughts in China based on a set of daily gridded(0.5° 9 0.5°) precipitation data from 1961 to 2014. By using a multi-threshold run theory approach to evaluate the monthly percentage of precipitation anomalies index(Pa), a drought events sequence was identified at each grid cell. The spatiotemporal variations of drought in China were further investigated based on statistics of the frequency, duration,severity, and intensity of all drought events. Analysis of the results show that China has five distinct meteorological drought-prone regions: the Huang-Huai-Hai Plain, Northeast China, Southwest China, South China coastal region,and Northwest China. Seasonal analysis further indicates that there are evident spatial variations in the seasonal contribution to regional drought. But overall, most contribution to annual drought events in China come from the winter. Decadal variation analysis suggests that most of China's water resource regions have undergone an increase in drought frequency, especially in the Liaohe, Haihe, and Yellow River basins, although drought duration and severity clearly have decreased after the 1960 s.

关键词： China Meteorological drought Multi-threshold run theory method Spatiotemporal variations

Laser-assisted Stark deceleration of CaF in its rovibronic ground (high-field-seeking) state

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Chinese Physics B 2019年第4期28卷 170-176页

作者： Yuefeng Gu Kai Chen Yunxia Huang xiaohua yang School of Science Nantong University State Key Laboratory of Precision Spectroscopy East China Normal University

A near-resonant, red-detuning laser-assisted Stark deceleration scheme is proposed to slow CaF in its high-fieldseeking rovibronic ground state. The assisting Gaussian laser beam can confine CaF molecules transversely owing to the optical Stark effect. Simulations suggest that the present scheme is superior to previous Stark decelerators. Under typical experimental conditions, when the assisting laser frequency is red-detuned to the molecular transition(λ～606.3 nm) by5.0 GHz and the laser power is about 5.6 W, the proposed decelerator can achieve a total number at the order of 10~4 CaF molecules with a number density at the order of 10~8 cm^(-3). The equivalent temperature of the obtained cold CaF molecules is 2.3 mK. Additionally, the desired assisting laser power can be as low as about 1.2 W if keeping the red-detuning value to be 1.0 GHz, which further suggests its experimental feasibility.

关键词： Stark deceleration polar molecule optical Stark effect high-field-seeking state

First-principle calculation of distorted T-carbon as a promising anode for Li-ion batteries with enhanced capacity, reversibility, and ion migration properties

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Carbon Energy 2020年第4期2卷 614-623页

作者： Jianrui Feng Chao yang Lijie Zhang Feili Lai Lei Du xiaohua yang Institut National de la Recherche Scientifique-Énergie Matériaux et Télécommunications VarennesQuebecCanada Department of Chemistry Zhejiang UniversityHangzhouChina School of Science Westlake UniversityHangzhouChina Institute of Material Science and Technologies Technical University BerlinBerlinGermany Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices School of Physics and ElectronicsHunan UniversityChangshaChina Department of Chemistry Katholieke Universiteit LeuvenLeuvenBelgium

Carbon group element-based materials are the most widely used anode materials for Li-ion batteries(LIBs).However,their performance is limited by the low capacity(eg,graphite)or high-volume changes(eg,Si and Sn).Therefore,exploring high-performance anode materials is quite appealing and *** first-principle calculations in this study,we found that distorted T-carbon(DTC)as a desired LIB anode shows properties of the enhanced capacity,decreased volume change,and the increased ion *** origin of such improved properties is attributed to the interconnected tunnels and large cavities of the carbon *** theoretical specific capacity of DTC is found to be 558 mAh/g,which is 1.5 times higher than that of commercial graphite ***,the volume change of the DTC anode is only 3%at the full-lithiation state(one-fifth of that of the commercial graphite anode),which can overcome the pulverization problem in most high-capacity anode materials and attain a longer cycling *** transition state calculations and molecular dynamics simulations demonstrate that the Li-ion migration barrier is less than 0.1 eV and the Li-ion vacancy is only 0.2 eV,enabling its promising rate *** study provides a new and effective strategy to improve the anode properties of LIBs.

关键词： density functional theory Li-ion batteries molecular dynamics nanomaterials T-carbon

Collision of cold CaF molecules: Towards evaporative cooling

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Chinese Physics B 2019年第3期28卷 161-167页

作者： Yuefeng Gu Yunxia Huang Chuanliang Li xiaohua yang School of Science Nantong UniversityNantong 226019China Department of Physics School of Applied ScienceTaiyuan University of Science and TechnologyTaiyuan 030024China State Key Laboratory of Precision Spectroscopy East China Normal UniversityShanghai 200062China

Long range intermolecular interaction potential surface of CaF(~2∑^+) was simulated by employing the MOLPRO program and using the RCCSD(T)/def2-TZVP theory. The predicted data were further fitted to obtain the collision crosssection. The elastic collision cross-section of CaF at the temperature around 2 mK is as high as 6.5 × 10^(-9) cm^2 and the collision rate is over 4.1 × 10~6 Hz. Additionally, we found that an orientation electric field will simplify the intermolecular interaction potential function from quaternary into ternary and the collision cross-section will be raised by about three orders. All-optical evaporative cooling of cold CaF is discussed in the conclusion.

关键词： intermolecular interaction potential energy surface cold collision evaporative cooling

The Belt and Road Initiative and the 2030 Agenda for Sustainable Development:seeking linkages for global environmental governance

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Chinese Journal of Population,Resources and Environment 2018年第3期16卷 203-210页

作者： Liang Dong xiaohua yang Hongtao Li Institute of Asian Studies China Foreign Affairs University Foreign Economic Cooperation Office Ministry of Ecology and Environment of the People's Republic of China

Global environmental cooperation serves as an important part in the Chinese ideal of building a Community with a Shared Future for all Human Beings. The report of 19 th CPC National Congress indicates that China is committed to proactive mitigation under the Paris Agreement and further participating in global environmental governance under the 2030 Agenda for Sustainable Development, and both of which are largely integrated to the Belt and Road Initiative(BRI). BRI are also closely linked with South-South environmental and climate cooperation proposed by China from previous UN summits. Based on shared ideas, intersected agendas, and compatible governance approaches, BRI and the 2030 Agenda for Sustainable Development grow increasingly relevant and they might form synergies based on increasingly interactive relations. In sum,seeking and intensifying the linkages between BRI and 2030 sustainable development goals(SDGs) could address global environmental governance deficits and enhance cooperation among nations.

关键词： The Belt and Road Initiative 2030 Agenda for Sustainable Development South-South cooperation interplay global environmental governance linkage climate change

Thermally Reversible,Self-Healing Polyurethane Based on Propyl Gallate and Polyurethane Prepolymers with Varied Isocyanate Content

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Journal of Renewable Materials 2020年第1期8卷 1-11页

作者： Haiyang Ding xiaohua yang Lina Xu Shouhai Li Jianling Xia Mei Li Institute of Chemical Industry of Forest Products(ICIFP) Nanjing210042China Key Laboratory of Biomass Energy and Material Nanjing210042China National Engineering Laboratory for Biomass Chemical Utilization Nanjing210042China Key and Open Laboratory on Forest Chemical Engineering SFANanjing210042China Co-Innovation Center of Efficient Processing and Utilization of Forest Resources Nanjing Forestry UniversityNanjing210042China

Thermosetting polyurethanes are widely used in various fields owing to their excellent elasticity,strength and solvent *** environmental friendly propyl gallate-based self-healing polyurethanes were prepared from polyurethane prepolymers with varying isocyanate *** thermal stabilities of the polyurethanes were tested using thermogravimetric *** self-healing and mechanical properties were analyzed using a universal testing machine and dynamic thermomechanical *** polyurethanes were found with high self-healing ability and excellent mechanical properties due to the absence of phenolic *** qualities improved with increased isocyanate content and the prolonged selfhealing *** found,therefore,that the propyl gallate-based polyurethane has potential for use in industrial applications as self-healing materials.

关键词： Propyl gallate thermosetting polyurethane self-healing ability mechanical property