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An Analytical APproach to the Turbulence—Relaxed State in Tokamak Plasmas

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communications in Theoretical Physics 2002年第6X期38卷 737-742页

作者： pengxiao-Dong QIUXiao-Ming SouthwesternInstituteofPhysics P.O.Box432Chengdu610041China

Starting from the continuity, temperature, and motion equations of the trapped electron fluid in generaltokamak magnetic field with positive or reversed shear and the definition of Lagrangian invariant, dL / dt = ( t +u. )L =0, where u is convective velocity, the trapped electron dynamics is considered in the following two assumptions: (i) theturbulence is low frequency electrostatic, and (ii) L is a functional only of the density n, temperature T, and magneticfield B, and the effect of perturbation potential φ is included in the convective velocity u, i.e., u is a functional of n,T, B, and φ. The Lagrangian invariant hidden in the trapped electron dynamics is strictly found: L= ln[(n/B)c1(T/B2/3)c2], where c1 and c2 are dimensionless changeable parameters and c1 ∝ c2. From this Lagrangian invariant thewhich, in the limit of large aspect ratio, reduce to n(r)q(r) = const. and T3/2(r)q(r) = const., respectively. The lattertwo scaling laws are compared with existent experimental results, being in good agreement.

关键词：托卡马克等离子体湍流态解析研究

Electrochemical conversion of methane to bridge the gap in the artificial carbon cycle

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Journal of Energy chemistry 2025年第1期100卷 286-308页

作者： Yuhao Peng Yuefeng Song Ihar Razanau Juanxiu Xiao wei Xiao Di Hu Guoxiong Wang college of chemistry and Molecular Sciences Hubei Key Laboratory of Electrochemical Power Sources Wuhan University State Key Laboratory of catalysis Dalian National Laboratory for Clean Energy iChEM (Collaborative Innovation Center of Chemistry for Energy Materials) Dalian Institute of Chemical Physics Chinese Academy of Sciences Laboratory of Physical-chemical Technologies SSPA Scientific and Practical Materials Research Centre of NAS of Belarus State Key Laboratory of Marine Resources Utilization in South china Sea Collaborative Innovation Center of Marine Science and Technology School of Marine Science and Engineering Hainan University Department of chemical and Environmental Engineering University of Nottingham Ningbo China

Methane, an abundant one-carbon（c1） resource, is extensively used in the industrial production of vital fuels and value-added chemicals. However, current industrial methane conversion technologies are energy-and carbon-intensive, mainly due to the high activation energy required to break the inert c–H bond, low selectivity, and problematic side reactions, including cO2emissions and coke deposition. Electrochemical conversion of methane（EcM） using intermittent renewable energy offers an attractive solution, due to its modular reactor design and operational flexibility across a broad spectrum of temperatures and pressures. This review emphasizes conversion pathways of methane in various reaction systems, highlighting the significance and advantages of EcM in facilitating a sustainable artificial carbon cycle. This work provides a comprehensive overview of conventional methane activation mechanisms and delineates the complete pathways of methane conversion in electrolysis contexts. Based on surface/interface chemistry, this work systematically analyzes proposed reaction pathways and corresponding strategies to enhance EcM efficiency towards various target products, including syngas, hydrocarbons, oxygenates, and advanced carbon materials. The discussion also encompasses opportunities and challenges for the EcM process, including insights into EcM pathways, rational electrocatalyst design, establishment of benchmarking protocols, electrolyte engineering, enhancement of cH4conversion rates, and minimization of cO2emission.

关键词： Methane Electrochemical conversion Reaction mechanism catalyst design Electrode Electrocatalysis

Simulation of Heat and Mass Transfer in a Grain Pile on the Basis of a 2D Irregular Pore Network

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Fluid Dynamics & Materials Processing 2019年第4期15卷 367-389页

作者： pengxiao chen Kai Huang Fenghe Wang weijun Xie Shuo wei Deyong Yang college of Engineering China Agricultural UniversityBeijingChina college of Engineering Nanjing Agricultural UniversityNanjingChina

The so-called pore network model has great advantages in describing the process of heat and mass transfer in porous *** order to construct a random two-dimensional(2D)irregular pore network model for an unconsolidated material,image processing technology was used to extract the required topological and geometric information from a 2D sample of soybean particles,and a dedicated algorithm was elaborated to merge some adjacent small *** on the extracted information,a 2D pore network model including particle information was reconstructed and verified to reflect the pore structure of discrete *** method was used to reconstruct a random 2D irregular pore network model of ***,a multi-scale heat and mass transfer model was implemented to simulate the drying of *** simulation results were consistent with the experimental results,which indicates that the reconstructed irregular pore network model can effectively simulate the real pore structure inside unconsolidated porous *** present approach may be regarded as the foundation for establishing in the future a three-dimensional pore network model and studying the heat and mass transfer process in a grain pile.

关键词： MATLAB pore network heat and mass transfer thiessen polygon

Application of moderate nitrogen levels alleviates yield loss and grain quality deterioration caused by post-silking heat stress in fresh waxy maize

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The crop Journal 2020年第6期8卷 1081-1092页

作者： Jue Wang pengxiao Fu weiping Lu Dalei Lu Jiangsu Key Laboratory of crop Genetics and Physiology/Jiangsu Key Laboratory of crop cultivation and Physiology Agricultural College of Yangzhou University/Jiangsu Co-Innovation Center for Modern Production Technology of Grain CropsYangzhou 225009JiangsuChina

High temperature(HT)during grain filling is one of the most important environmental factors limiting maize yield and grain ***(N)fertilizer is essential for maintaining normal plant growth and defense against environmental *** effects of three N rates and two temperature regimes on the grain yield and quality of fresh waxy maize were studied using the hybrids Suyunuo 5(SYN5)and Yunuo 7(YN7)as materials.N application rates were 1.5,4.5,and 7.5 g plant-1,representing low,moderate,and high N levels(LN,MN,and HN,respectively).Mean day/night temperatures during the grain filling of spring-and summer-sown plants were 27.6/21.0°c and 28.6/20.0°c for ambient temperature(AT)and 35/21.0°c and 35/20.0°c for HT,*** average,HT reduced kernel number,weight,yield,and moisture content by 29.8%,17.9%,38.7%,and 3.3%,*** number,weight,yield,moisture,and starch contents were highest under MN among the three N rates under both temperature *** reduced grain starch content at all N *** increased grain protein content,which gradually increased with N *** starch granule size under MN was larger(10.9μm)than that under LN and HN(both 10.4μm)at ***,the mean size of starch granules was higher under LN(11.7μm)and lower under MN(11.2μm)at *** binding capacity(IBc)was lowest under MN and highest under HN among the three N levels under both temperature *** general,IBc at all N rates was increased by *** viscosity(PV)was gradually reduced with increasing N rate at *** comparison with LN,PV was increased by MN and decreased by HN at *** percentage gradually increased with N rate at AT,but was lowest under MN among the three N rates at ***+AT and MN+HT produced grain with high pasting viscosity and low retrogradation *** application could alleviate the negative effects of HT on the grain yield and quality of fresh waxy maize.

关键词： Fresh waxy maize Grain quality Heat stress Nitrogen rate Starch granule size

Infrasonic waves generated from the volcano eruption in Tonga

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chinese Journal of Acoustics 2022年第1期41卷 95-98页

作者： cHENG wei TENG pengxiao LYU Jun ZHANG Tianyu Institute of Acoustics Chinese Academy of SciencesBeijing 100190 Key Laboratory of Noise and Vibration Research Chinese Academy of SciencesBeijing 100190 University of chinese Academy of Sciences Beijing 100049

The Hunga-Tonga-Hunga-Ha’apai volcano in Tonga erupted violently on January 15,*** 8 hours and 39 minutes,an infrasound array in Kunming at a distance of 10151 km away from the volcano recorded a sequence of strong infrasonic *** average period of the first four infrasonic waves is 443 s with propagation speed of 321 m/*** azimuth angle of this event has been estimated by applying the progressive multi-channel correlation(PMcc)method to process the received *** continuous monitoring,the infrasonic waves propagating along and opposite to the direction towards the Kunming array around the earth are recorded respectively.

关键词： volcano eruption record

Research Issues of Applying Radio Frequency Identification （RFID） in Supply chain Management

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Research Issues of Applying Radio Frequency Identification ...

constructing highly dispersed 0D co3S4 quantum dots/2D g-c3N4 nanosheets nanocomposites for excellent photocatalytic performance

The Fourth International conference on Information and Management Sciences

作者： Jerry c.wei Mendoza college of Business University of Notre DameNotre DameIN 46556

＜正＞ This paper examines the basic components and characteristics of the RFID technology. It addresses several issues of implementation and diffusion of the technology. The paper points out that there is a great need for rigorous academic research while the implementation of RFID is in flux. It then discusses some open issues for research and presents examples of research problems.

关键词： RFID Supply chain Information Technology

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Science Bulletin 2019年第20期64卷 1510-1517页

作者： Hongcen Yang Jiangmei Yin Ruya cao pengxiao Sun Shouwei Zhang Xijin Xu School of Physics and Technology University of Jinan

The development of noble-metal-free catalysts with high efficiency photocatalytic properties is critical to the heterogeneous catalysis. Herein, zero-dimensional(0 D) metal sulfide quantum dots/two-dimensional(2 D) g-c3N4 nanosheets(co3S4/cNNS) nanocomposites are synthesized by a two-step method, including the ways of in-situ deposition and water bath. The highly dispersed co3S4 quantum dots(particle size is2–4 nm) are evenly and tightly fixed on cNNS, which can be used as co-catalyst to effectively replace noble metals to improve the photocatalytic properties of cNNS. co3S4/cNNS-900 has the apparent quantum efficiency, which is up to 7.85% at 400 nm. At the same time, the H2 evolution rate of co3S4/cNNS-900 is 20,536.4 lmol gà1 hà1, which is 555 times than cNNS. The excellent photocatalytic performance is due to the highly dispersed co3S4 quantum dots on 2 D cNNS, which facilitate the formation of more active sites, co3S4/cNNS promotes the separation and migration of photogenerated carriers, shortens the migration distance of photogenerated carriers, and eventually leads to an increase of the photocatalytic performance.

关键词： co3S4 g-c3N4 Photocatalysis

A low redox potential and long life organic anode material for sodium-ion batteries

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Journal of Energy chemistry 2025年第1期100卷 557-564页

作者： Zhi Li Yang wei Kang Zhou Xin Huang Xing Zhou Jie Xu Taoyi Kong Junwei Lucas Bao Xiaoli Dong Yonggang Wang Department of chemistry and Shanghai Key Laboratory of Molecular catalysis and Innovative Materials Institute of New Energy Collaborative Innovation Center of Chemistry for Energy Materials (iChEM) Fudan University Department of chemistry Boston College School of Materials Science and Engineering Anhui University of Technology

Sodium-ion batteries （SIBs） with organic electrodes are an emerging research direction due to the sustainability of organic materials based on elements like c,H,O,and sodium ***,organic electrode materials for SIBs are mainly used as cathodes because of their relatively high redox potentials（>1 V）.Organic electrodes with low redox potential that can be used as anode are ***,a novel organic anode material （tetrasodium 1,4,5,8-naphthalenetetracarboxylate,Na4TDc） has been developed with low redox potential （cellent cyclic *** three-sodium storage mechanism was demonstrated with various in-situ/ex-situ spectroscopy and theoretical calculations,showing a high capacity of 208 mAh/g and an average decay rate of merely 0.022%per ***,the Na4TDc-hard carbon composite can further acquire improved capacity and cycling stability for 1200 cycles even with a high mass loading of up to 20 mg *** pairing with a thick Na3V2（PO4）3cathode (20.6 mg cm-2),the as-fabricated full cell exhibited high operating voltage （2.8 V）,excellent rate performance and cycling stability with a high capacity retention of 88.7% after 200 cycles,well highlighting the Na4TDc anode material for SIBs.

关键词： Organic anode material Low redox potential composite anode Sodium-ion batteries

Tunable tribological properties in water-based lubrication of water-soluble fullerene derivatives via varying terminal groups

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chinese Science Bulletin 2012年第35期57卷 4641-4645页

作者： LIU YuHong LIU pengxiao cHE Lu SHU chunYing LU Xinchun State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China Key Laboratory of Molecular Nanostructure and Nanotechnology Institute of ChemistryChinese Academy of SciencesBeijing 100190China

In this paper,three kinds of water-soluble fullerene derivatives were synthesized via electrophilic addition reaction and cycloaddition reaction,*** chemical composition characterizations of these derivatives indicated the successful preparation of c60(OH)x,c60(c(cOOH)2)x and c60(OH)x(NHcH2cOOH)y fullerene *** aggregation and morphology characterizations showed that the three kinds of derivatives had an ideal spherical aggregating structures and excellent dispersibility in water,especially c60(OH)x and c60(c(cOOH)2) *** lubrication performance of the fullerene derivatives acted as lubricant additives were investigated at different concentrations in the range of 0-1 wt%.The results indicated that the addition of polyhydroxyl and carboxylic derivatives could improve the lubrication properties,which led to the reduction of wear to about 40% at *** is attributed that the optimized substitutions of fullerene molecules may be of benefit to their distribution properties and lubricating behaviors in water based lubrication.

关键词：富勒烯衍生物润滑油添加剂水溶性摩擦学性能水基调谐基团亲电加成反应