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Free-radical evolution and decay in cross-linked polytetrafluoroethylene irradiated by gamma-rays

Nuclear science and Techniques 2022年第5期33卷 113-125页

作者： Fei-Xiang Sha Guo-Jun Cheng Zi-Yue Xuan Yang Liu Wei-Hua Liu Xiao-Dong Zhang Zhong-Feng Tang School of Materials Science and Engineering Anhui University of Science and TechnologyHuainan 232000China Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China National Key Laboratory of Materials Behavior and Evaluation Technology in Space Environment Harbin Institute of TechnologyHarbin 150001China University of Chinese Academy of Sciences Beijing 100049China

Electron spin resonance techniques were employed to investigate the effects of the absorbed dose and post-irradiation conditions on the evolution and decay of free-radicals in cross-linked polytetrafluoroethylene(XPTFE),induced byγ-ray ***-end free-radicals,chain alkyl free-radicals,and tertiary alkyl free-radicals were detected when XPTFE was irradiated under Ar *** corresponding peroxy free-radicals were formed upon exposure of irradiated XPTFE to air;the freeradicals concentration first increased linearly with increasing absorbed dose and then gradually *** free-radicals yield under air atmosphere was greater than that under Ar,and the peroxy free-radicals were preserved for a relatively long time when irradiated XPTFE was stored under air *** chain alkyl free-radicals may be converted to chain end free-radicals byβ-scission,while chain end free-radicals are more sensitive to oxygen than chain alkyl *** the annealing temperature was raised above the a-transition temperature of XPTFE,the decay of the free-radicals was greatly affected and accelerated by the motion of the molecules over the long range.

关键词： Polytetrafluoroethylene Cross-linked polytetrafluoroethylene Electron spinresonance Decay Radiation c-ray

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Quantitative analysis of the tribological properties of phosphate glass at the nano- and macro-scales

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Friction 2021年第5期9卷 1138-1149页

作者： Huimin QI Wen HU Hongtu HE Yafeng ZHANG Chenfei SONG Jiaxin YU Key Laboratory of Testing Technology for Manufacturing Process in Ministry of Education State Key Laboratory of Environment-friendly Energy MaterialsSouthwest University of Science and TechnologyMianyang 621010China National United Engineering Laboratory for Advanced Bearing Tribology Henan University of Science and TechnologyLuoyang 471023China

Processing(grinding,polishing)of phosphate laser(PL)glass involves material removal at two vastly different(spatial)*** this study,the nano‐and macro‐tribological properties of PL glass are investigated by rubbing the glass against a SiO_(2) counter‐surface in both dry and humid *** results indicate that the friction of the PL glass/SiO_(2) pair has opposing trends at the nano‐and *** the nanoscale,the friction coefficient(COF)in humid air is much higher than in dry air,which is attributed to the capillary effect of the absorbed water‐film at the *** the macroscale,on the other hand,the COF in humid air is lower than in dry air,because the water‐related mechanochemical wear makes the worn surface less susceptible to *** removal for PL glass is better facilitated by humid air than by dry air at both scales,because the stress‐enhanced hydrolysis accelerates the material‐removal process in ***,the material‐removal is more sensitive to contact pressure at the macroscale,because stronger mechanical‐interaction occurs during material removal at the macroscale with the multi asperity contact *** the macroscale,the material removal is more sensitive to contact pressure in humid air compared to dry *** almost all mechanical energy is used to remove material in humid air,and most of the mechanical energy is used to produce cracks in PL glass in dry *** results of this study can help optimize the multi‐scale surface processing of optical glasses.

关键词： phosphate glass friction wear water hydrolysis tribochemistry

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Remote Sensing of Tropospheric Ozone from Space:Progress and Challenges

Journal of Remote Sensing

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Journal of Remote Sensing 2024年第1期4卷 324-343页

作者： Jian Xu Zhuo Zhang Lanlan Rao Yapeng Wang Husi Letu Chong Shi Gegen Tana Wenyu Wang Songyan Zhu Shuanghui Liu Entao Shi Yongmei Wang Liangfu Chen Xiaolong Dong Jiancheng Shi National Space Science Center Chinese Academy of SciencesBeijingChina Key Laboratory of Microwave Remote Sensing Technology Chinese Academy of SciencesBeijingChina Beijing Key Laboratory of Space Environment Exploration BeijingChina Key Laboratory of Science and Technology on Environmental Space Situation Awareness Chinese Academy of SciencesBeijingChina National Satellite Meteorological Center China Meteorological AdministrationBeijingChina Aerospace Information Research Institute Chinese Academy of SciencesBeijingChina School of GeoSciences University of EdinburghEdinburghUK School of Astronomy and Space Science University of Chinese Academy of SciencesBeijingChina School of Electronic Electrical and Communication EngineeringUniversity of Chinese Academy of SciencesBeijingChina

Ozone stands out as a crucial trace gas within the Earth’s atmosphere,exerting a substantial influence on climate change and air *** ozone plays an important role in the formation of photochemical smog,and its variations are associated with human *** utilization of satellite remote sensing technology for tropospheric ozone monitoring enables a quantitative analysis of its global and regional spatiotemporal *** also facilitates the investigation of the mechanisms involved in ozone formation within the *** significant progress in product accuracy and spatiotemporal resolution of ozone remote sensing products,including total ozone and vertical profiles,can be attributed to the extensive development of satellite remote sensing ***,the precision of tropospheric ozone products remains inadequate for contemporary scientific purposes,primarily because of faint signals in the lower atmosphere,the intricate nature of the underlying surface,and the existence of clouds and *** study places emphasis on the satellite remote sensing of tropospheric ozone,encompassing a comprehensive review of the advancements in satellite sensors and the characteristics and suitability of various retrieval ***,this research delves into the possible utilization of satellite remote sensing for the provision of reliable tropospheric ozone observation data on a global and regional level.

关键词： satellite remote sensing technology tropospheric ozone satellite remote sensing air pollutiontropospheric ozone investigation mechanisms photochemical smogand trace gas climate change

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Electrolyte engineering for High-Voltage Lithium Metal Batteries

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Research 2022年第4期2022卷 781-832页

作者： LiweiDong Shijie Zhong Botao Yuan Yuanpeng Ji Jipeng Liu Yuanpeng Liu Chunhui Yang Jiecai Han Weidong He MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage School of Chemistry and Chemical EngineeringHarbin Institute of TechnologyHarbin 150080China National Key Laboratory of Science and Technology on Advanced Composites in Special Environments and Center for Composite Materials and Structures Harbin Institute of TechnologyHarbin 150080China State Key Laboratory of Urban Water Resource and Environment Harbin Institute of TechnologyHarbin 150080China Chongqing Research Institute Harbin Institute of TechnologyChongqing 401151China School of Mechanical Engineering Chengdu UniversityChengdu610106China

High-voltage lithium metal batteries(HVLMBs)have been arguably regarded as the most prospective solution to ultrahigh-density energy storage devices beyond the reach of current ***,the only component inside the HVLMBs in contact with both aggressive cathode and Li anode,is expected to maintain stable electrode/electrolyte interfaces(EEIs)and facilitate reversible Li+***,traditional electrolytes with narrow electrochemical windows fail to compromise the catalysis of high-voltage cathodes and infamous reactivity of the Li metal anode,which serves as a major contributor to detrimental electrochemical performance fading and thus impedes their practical *** stable electrolytes is vital for the further development of ***,optimization principles,design strategies,and future perspectives for the electrolytes of the HVLMBs have not been summarized in *** review first gives a systematical overview of recent progress in the improvement of traditional electrolytes and the design of novel electrolytes for the *** strategies of conventional electrolyte modification,including high concentration electrolytes and CEI and SEI formation with additives,are *** electrolytes including fluorinated,ionic-liquid,sulfone,nitrile,and solid-state electrolytes are also *** addition,theoretical studies and advanced characterization methods based on the electrolytes of the HVLMBs are probed to study the internal mechanism for ultrahigh stability at an extreme *** also foresees future research directions and perspectives for further development of electrolytes in the HVLMBs.

关键词： electrolyte maintain summarized

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N-Heterocyclic Carbene Coordinated Cu Single Atoms on Poly(ionic Liquid)for Selective Electroreduction of CO_(2)to CH_(4) at High Current Density

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CCS Chemistry 2024年第12期6卷 3041-3052页

作者： Biao Meng Yujie Cao Xiao Chi Xiaoling Liu Wenwen Guan Chao Wu Xiaojiang Yu Siyu Zhu Yizhong Huang Yu Zhou Shibo Xi Jun Wang State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringNanjing Tech UniversityNanjing 211816 Department of Physics National University of SingaporeSingapore 117576 Institute of Sustainability for Chemicals Energy and Environment(ISCE2)Agency for ScienceTechnology and Research(A*STAR)Singapore 627833 College of Materials Science and Engineering Sichuan UniversityChengdu 610065 Synchrotron Light Source National University of SingaporeSingapore 117603 School of Materials Science and Engineering Nanyang Technological UniversitySingapore 639798

Finely adjusting the local environment of Cu single atom(SA)is crucial but challenging for the fabrication of electrocatalysts for the CO_(2)reduction reaction(CO_(2)RR)to produce clean energy methane(CH_(4)).Herein,poly(ionic liquid)s-stabilized Cu SAs with tunable Br-Cu-Cx configuration were directly synthesized through the self-polymerization of the ionic liquid monomer,a bis-vinylimidazolium salt,in the presence of Cu *** X-ray absorption fine structure,soft X-ray absorption,and X-ray photoelectron spectroscopy analyses showed that the Cu SAs were coordinated with N-heterocyclic carbene derived from the imidazole *** optimal catalyst Cu@P-2 with moderate Cu loading afforded a high Faradaic efficiency of∼70%at a high current of-250 mA cm^(-2)in the CO_(2)RR to CH_(4),associating with a turnover frequency as high as 1.0 s^(-1).This outstanding performance is assigned to the high density Cu SAs reaching strong affinity towards*CO intermediates in the case of moderate Cu loading,as revealed by in situ attenuated total reflection surface-enhanced infrared absorption spectroscopy analysis and theoretical calculated free energy profiles of CO_(2)RR to CH_(4).

关键词： electrocatalysis CO_(2)conversion poly(ionic liquid) single atom catalyst CH_(4)production

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Fe-Ni-F electrocatalyst for enhancing reaction kinetics of water oxidation

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Chinese Journal of Structural Chemistry 2024年第2期43卷 60-65页

作者： Yi Zhang Biao Wang Chao Hu Muhammad Humayun Yaping Huang Yulin Cao Mosaad Negem Yigang Ding Chundong Wang School of Chemical Engineering and Pharmacy Key Laboratory of Green Chemical Process of Ministry of EducationKey Laboratory of Novel Reactor and Green Chemical Technology of Hubei ProvinceWuhan Institute of TechnologyWuhan430073PR China Energy Waterand Environment LabCollege of Humanities and SciencesPrince Sultan UniversityRiyadh11586Saudi Arabia School of Integrated Circuits Wuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhan430074PR China Physics Laboratory Industrial Training CenterShenzhen Polytechnic UniversityShenzhen518055PR China Chemistry Department Faculty of ScienceFayoum UniversityFayoum63514Egypt

Highly active and low-cost oxygen evolution reaction(OER)catalytic electrodes are extremely essential for exploration of green hydrogen via water ***,an advanced Fe-Ni-F electrocatalyst is fabricated by a facile annealing strategy using ammonium fluoride,of which the structure feature is unveiled by XRD,FESEM,TEM,EDS,BET,and XPS *** as-prepared Fe-Ni-F addresses a low overpotential of 277 mV and a small Tafel slope of 49 mV dec^(-1)at a current density of 10 mA cm^(-2),significantly outperforming other control samples as well as the state-of-the-art RuO_(2).The advanced nature of our Fe-Ni-F catalyst could also be further evidenced from the robust stability in KOH alkaline solution,showing as 5.41%degradation after 24 h continuous *** analysis,it suggests that the decent catalytic activity should be attributed to the formed bimetallic(oxy)hydroxides because of the introduction of fluoride and the synergistic effect of iron and nickel towards oxygen *** work represents the potential of Fe-and/or Ni-based fluoride as efficient catalyst for low-energy consumption oxygen generation.

关键词： Fluoride Oxygen evolution reaction Fe-Ni-F Reaction kinetics

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Migration of ammonium nitrogen in ion-absorbed rare earth soils during and post in situ mining: a column study and numerical simulation analysis

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Frontiers of environmental science & engineering 2023年第8期17卷 137-151页

作者： Gaosheng Xi Xiaojiang Gao Ming Zhou Xiangmei Zhai Ming Chen Xingxiang Wang Xiaoying Yang Zezhen Pan Zimeng Wang Department of Environmental Science and Engineering Fudan UniversityShanghai 200438China School of Resource and Environmental Engineering Jiangxi University of Science and TechnologyGanzhou 341000China CAS Key Laboratory of Soil Environment and Pollution Remediation Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary Shanghai 202151China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200001China

Ion-absorbed rare earth mines,leached in situ,retain a large amount of ammonium nitrogen(NH4–N)that continuously releases into the surrounding ***,quantitative descriptions and predictions of the transport of NH4–N across mining area with hill slopes are not fully ***,laboratory column experiments were designed with an inclined slope(a sand box)to examine the spatial temporal transport of NH4–N in soils collected from the ionic rare earth elements(REE)mining *** HYDRUS-2D model simulation of the experimental data over time showed that soils had a strong adsorption capacity toward NH4–*** non-equilibrium model(CNEM)could well simulate the transport of NH4–N through the soil-packed *** simulation of the transport-adsorption processes at three flow rates of leaching agents revealed that low flow rate enabled a longer residence time and an increased NH4-N adsorption,but reduced the extraction efficiency for *** the subsequent rainwater washing process,the presence of slope resulted in the leaching of NH4–N on the surface of the slope,while the leaching of NH4–N deep inside the column was ***,the high-intensity rainfall significantly increased the leaching,highlighting the importance of considering the impact of extreme weather conditions during the leaching ***,our study advances the understanding of the transport of NH4–N in mining area with hills,the impact of flow rates of leaching agents and precipitation intensities,and presents as a feasible modeling method to evaluate the environmental risks of NH4–N pollution during and post REE in situ mining activities.

关键词： Ion-absorbed rare earth Ammonium nitrogen transport HYDRUS-2D Numerical simulation

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Perovskite films with gradient bandgap for self-powered multiband photodetectors and spectrometers

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Nano Research 2023年第7期16卷 10256-10262页

作者： Chuantian Zuo Lixiu Zhang Xiyan Pan He Tian keyou Yan Yuanhang Cheng Zhiwen Jin Chenyi Yi Xiaoliang Zhang Wu-Qiang Wu Qinye Bao Liyuan Han Liming Ding Center for Excellence in Nanoscience(CAS) Key Laboratory of Nanosystem and Hierarchical Fabrication(CAS)National Center for Nanoscience and TechnologyBeijing 100190China School of Physics and Electronic Science East China Normal UniversityShanghai 200241China School of Integrated Circuits Tsinghua UniversityBeijing 100084China School of Environment and Energy South China University of TechnologyGuangzhou 510000China School of New Energy Nanjing University of Science and TechnologyJiangyin 214443China School of Physical Science and Technology Lanzhou UniversityLanzhou 730000China State Key Laboratory of Power System Department of Electrical EngineeringTsinghua UniversityBeijing 100084China School of Materials Science and Engineering Beihang UniversityBeijing 100191China School of Chemistry Sun Yat-sen UniversityGuangzhou 510006China State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong UniversityShanghai 200240China Key Laboratory of Semiconductor Materials Science Beijing Key Laboratory of Low Dimensional Semiconductor Materials and DevicesInstitute of SemiconductorsChinese Academy of SciencesBeijing 100083China

Bandgap-graded materials present varying spectral responses at different positions,making them possible to be used as an alternative to photoactive materials array in multi-spectral responsive devices,thus miniaturizing the ***,the preparation of bandgap-graded materials usually requires complicated deposition *** we report a facile lowtemperature solution process to make films with lateral bandgap gradients,which form spontaneously via self-spreading and interdiffusion of *** show lead halide perovskite films with MAPbCl_(3)-MAPbBr_(3)and MAPbBr_(3)-MAPbI_(3)gradients,which exhibit light absorption onsets ranging from 410 to 781 *** bandgap-graded films were used to make self-powered multiband photodetectors,which show different spectral responses at different positions without applying bias ***,self-powered spectrometers were made by using the multiband photodetectors.

关键词： self-spreading interdiffusion bandgap-graded perovskite multiband photodetectors self-powered spectrometers

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Preparation and Properties of High Temperature Transient Thin Film Thermopile Heat Flux Sensor

SSRN

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SSRN 2024年

作者： Xie, Shanghang Zhu, Jin Jiang, Hongchuan Zhao, Xiaohui Liu, Baorui Jia, Zhouxia State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of China Chengdu610054 China Science and Technology on Reliability and Environment Engineering Laboratory Beijing Institute of Structure and Environment Engineering Beijing100076 China

The thermopile of the sensor consists of 192 pairs Pt-PtRh10 thermocouples with length 1 mm and width 100 μm in serpentine series were deposited on Al2O3 ceramic substrates by photolithography-coating process. The thermal resistance layers with the proposed low thermal conductivity coefficient features a meshed cavity structure, four thermal resistance layers were spaced over the thermopile contacts to enhance the sensitivity of the sensor. Calibration of the sensor’s sensitivity was performed by a flat-plate radiative heat flux device, while its response time was measured by pulsed laser. Finally, the sensor’s performance in an actual application environment was simulated using a wind tunnel. The results showed that the thin film heat flux sensor can operate in environments ranging from 200 to 1500 ℃, with a sensitivity of 0.03067 m2·μV/W, the maximum relative error is 8.5% and an average response time of 12.7 μs. The sample exhibited stable performance during wind tunnel testing, responding quickly to changes in heat flux. © 2024, The Authors. All rights reserved.

关键词： Thermocouples

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Effect of Penetration Rates on the Piezocone Penetration Test in the Yellow River Delta Silt

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Journal of Ocean University of China 2022年第2期21卷 361-374页

作者： ZHANG Jiarui MENG Qingsheng ZHANG Yan FENG Xiuli WEI Guanli SU Xiuting LIU Tao College of Environmental Science and Engineering Ocean University of ChinaQingdao 266100China Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering Ocean University of ChinaQingdao 266100China Laboratory for Marine Geology Qingdao National Laboratory for Marine Science and TechnologyQingdao 266061China College of Marine Geosciences Ocean University of ChinaKey Laboratory of Submarine Geosciences and ProspectingQingdao 266100China

Partial drainage often occurs during piezocone penetration testing on Yellow River Delta silt because of its intermediate physical and mechanical properties between those of sand and ***,there is no accurate understanding for the range of penetra-tion rates to trigger the partial drainage of silt *** order to fully investigate cone penetration rate effects under partial drainage condi-tions,indoor 1 g penetration model tests and numerical simulations of cavity expansion at variable penetration rates were carried out on the Yellow River Delta *** boundary effect of the model tests and the variation of key parameters at the different cavity ex-pansion rates were *** 1 g penetration model test results and numerical simulations results consistently indicated that the penetration rate to trigger the partially drainage of typical silt varied at least three orders of *** numerical simulations also provide the reference values for the penetration resistance corresponding to zero dilation and zero viscosity at any given normalized penetration rate for silt in Yellow River *** geotechnical properties can be used for the design of offshore platforms in Yel-low River Delta,and the understanding of cone penetration rate effects under the partially drained conditions would provide some technical support for geohazard evaluation of offshore platforms.

关键词： Yellow River Delta silt cone penetration rate effects 1g model simulation numerical analysis

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