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Nano Research 2023年第4期16卷 4793-4802页

作者： Weiyuan Ding Ali Saad yuchen Wu Zhiwei Wang Xiuting Li Institute for Advanced Study Shenzhen UniversityShenzhen 518060China College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhen 518060China

Rational construction of active components has been the biggest challenge in preparing efficient bifunctional oxygen ***,electrospinning and chemical vapor deposition(CVD)were employed to embed active species including FeCo nanoparticles,MNx(M=Fe,Co),and FePx in porous and graphitized carbon nanotubes(CNTs)/carbon nanofiber(CNF).The as-prepared FeCo@CoNx@FePx/C exhibited a half-wave potential as high as 0.86 V in oxygen reduction reaction(ORR)and low oxygen evolution reaction(OER)overpotential of 368 mV at 10 mA·cm^(−2),which are superior to Pt/C(0.83 V)and IrO_(2)(375 mV)*** assembled Zn-air battery(ZAB)showed a high energy efficiency(Edischarge/Echarge)of 65%at 20 mA·cm^(−2)and stabilized for 700 charge-discharge *** spectroscopic and microscopic characterizations evidenced that the outstanding bifunctionality of the electrocatalyst can be ascribed to three main reasons:First,FeCo nanoparticles are rich in MOH/MOOH active sites for OER,and FePx/CNTs constructed with CVD also modulate electronic structure to improve electron transfer;second,both MNx in carbon matrix and FePx/CNTs are highly active towards ORR;third,the CNTs/CNF are highly porous and graphitized,which promotes mass transport and improves electrical conductivity and stability of the *** work gives important implications on the design of bifunctional electrocatalysts.

关键词： carbon nanotubes(CNTs)/carbon nanofiber(CNF)-supported multi-active components oxygen reduction reaction oxygen evolution reaction zinc-air battery

Spin logic devices based on negative differential resistance -enhanced anomalous Hall effect

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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1437-1448页

作者： Hongming Mou Ziyao Lu yuchen Pu Zhaochu Luo Xiaozhong Zhang Key Laboratory of Advanced Materials(MOE) School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China State Key Laboratory of Artificial Microstructure and Mesoscopic Physics School of PhysicsPeking UniversityBeijing 100871China

Owing to rapid developments in spintronics,spin-based logic devices have emerged as promising tools for next-generation computing *** paper provides a comprehensive review of recent advancements in spin logic devices,particularly focusing on fundamental device concepts rooted in nanomagnets,magnetoresistive random access memory,spin–orbit torques,electric-field modu-lation,and magnetic domain *** operation principles of these devices are comprehensively analyzed,and recent progress in spin logic devices based on negative differential resistance-enhanced anomalous Hall effect is *** devices exhibit reconfigur-able logic capabilities and integrate nonvolatile data storage and computing *** current-driven spin logic devices,negative differential resistance elements are employed to nonlinearly enhance anomalous Hall effect signals from magnetic bits,enabling reconfig-urable Boolean logic ***,voltage-driven spin logic devices employ another type of negative differential resistance ele-ment to achieve logic functionalities with excellent cascading *** cascading several elementary logic gates,the logic circuit of a full adder can be obtained,and the potential of voltage-driven spin logic devices for implementing complex logic functions can be *** review contributes to the understanding of the evolving landscape of spin logic devices and underscores the promising pro-spects they offer for the future of emerging computing schemes.

关键词： spin logic spin–orbit torque negative differential resistance full-adder

Bifunctional Fe-doped CoP@Ni_(2)P heteroarchitectures for highefficient water electrocatalysis

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Nano Research 2022年第10期15卷 8865-8871页

作者： Zhongxin Duan Depeng Zhao yuchen Sun Xiaojie Tan Xiang Wu School of Materials Science and Engineering Shenyang University of TechnologyShenyang 110870China

It is important to develop economical and durable electrocatalysts for sustainable energy conversion ***,the current catalysts still suffer from insufficient hydrogen adsorption ***,we report a kind of novel bi-phosphide catalyst through constructing heterogeneous structures and cation *** obtained sample delivers an outstanding hydrogen evolution reaction(HER)performance at all pH *** oxygen evolution reaction(OER)electrocatalyst,Fe-CoP@Ni_(2)P samples show an overpotential of 237 mV at 50 mA·cm^(−2) in alkaline *** electrolysis of water,Fe-CoP@Ni_(2)P catalysts deliver a cell voltage of 1.59 V at 50 mA·cm^(−2) and long ***,density functional theory(DFT)calculation further confirms that the doped heterostructure promotes Gibbs free energy for hydrogen *** the significant increase in the density of total states(DOS)also enhances the catalytic activity of HER.

关键词： Fe doping phosphide heterostructure all pH range hydrogen evolution reaction(HER) electrolysis

Impact of chlorites on the wettability of tight oil sandstone reservoirs in the Upper Triassic Yanchang Formation,Ordos Basin,China

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Science China Earth Sciences 2021年第6期64卷 951-961页

作者： Zhongnan WANG Xiaorong LUO Keyu LIU yuchen FAN Xiangzeng WANG Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao266580China School of Geosciences China University of Petroleum(East China)Qingdao266580China Key Laboratory of Petroleum Resources Research Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and TechnologyQingdao266071China Shanxi Yanchang Petroleum(Group)Co. Ltd.Xi’an710075China

Wettability is an essential property of reservoirs that is of great importance for enhancing oil recovery(EOR)and oil *** wettability of reservoirs is generally believed to be strongly affected by mineral compositions but it is not always the *** integrated study of petrography and wettability was carried out to determine the impact of chlorite minerals on the wettability of the sandstone reservoirs in the Upper Triassic Yanchang *** are found to be commonly present in the reservoir sandstones as detrital grains,rim-shaped cements,and biotite-chloritized forms with the pore peripheries being largely coated by chlorite,which is the main mineral in direct contact with *** pore scale,the wetting state of chlorites can either be oil-wet or water-wet in the tight sandstone reservoirs depending on wettability alteration by oil *** in contact with pores occupy a large of proportions of oil-wet pore walls and are crucial for the formation of oil-wetting state of reservoir *** core scale,the contents of chlorites in direct contact with pores do not correlate well with the AmottHarvey index due to other factors such as heterogeneity,oil-bearing degrees of samples.

关键词： Wettability Chlorite Pore scale Core scale Yanchang Formation Ordos Basin

Bioassay of Carcinoembryonic Antigens by Organic Field-effect Transistors Based on D-A Type Conjugated Polymer

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Chemical Research in Chinese Universities 2023年第6期39卷 877-883页

作者： LYU Xiaomeng DUAN yuchen CHEN Yulan CHENG Shanshan Tianjin Key Laboratory of Molecular Optoelectronic Science Department of ChemistryTianjin UniversityTianjin 300354P.R.China State Key Laboratory of Supramolecular Structure and Materials College of ChemistryJilin UniversityChangchun 130012P.R.China

Biosensors based on organic field-effect transistors(OFETs)are one of the most promising electronic devices for emerging bioanalytical *** selection of organic semiconductors(OSCs)is essential to improve the sensitivity and reliability of this kind of *** the good field effect performance and tunable structures of D-A type conjugated polymers,here,we design two D-A type copolymers[P(BDT-co-DPP2T-ThC_(2))and P(BDT-co-DPP2T-Th)],which are applied as the OSC *** carcinoembryonic antigen antibody(anti-CEA)adsorbed onto the OSC layers as the recognition sites,OFETs based biosensors for CEA detection are *** experimental findings support that the attachment of ester side groups onto the polymer backbone[as for P(BDT-co-DPP2T-ThC_(2))]is favorable for improved solubility and filming properties of the *** introduction of ester side groups affects molecular stacking and enhances intermolecular *** resultant devices show high charge mobility and antibody adsorption ability,both of which are critical for sensitive and facile detection of CEA *** reliable determination of CEA down to the picomolar level is *** is expected that this kind of biosensors fabricated by D-A type conducting polymers will open new avenues toward the early diagnosis,real-time monitoring and treatment of future cancer diseases.

关键词： Organic field-effect transistor Conjugated polymer Carcinoembryonic antigen Biosensor Semiconductor

Experimental crushing behavior and energy absorption of angular gradient honeycomb structures under quasi-static and dynamic compression

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Defence Technology（防务技术） 2024年第6期36卷 47-63页

作者： Jiachen Li yuchen Wei Hao Wu Xingyu Shen Mengqi Yuan State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China Institute of Occupational Health China Academy of Safety Science and TechnologyBeijing 100012China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China

The high variability of shock in terrorist attacks poses a threat to people's lives and properties,necessitating the development of more effective protective *** study focuses on the angle gradient and proposes four different configurations of concave hexagonal honeycomb *** structures'macroscopic deformation behavior,stress-strain relationship,and energy dissipation characteristics are evaluated through quasi-static compression and Hopkinson pressure bar impact *** study reveals that,under varying strain rates,the structures deform starting from the weak layer and exhibit significant interlayer ***,interlayer shear slip becomes more pronounced with increasing strain *** terms of quasi-static compression,symmetric gradient structures demonstrate superior energy absorption,particularly the symmetric negative gradient structure(SNG-SMS)with a specific energy absorption of 13.77 J/cm~*** dynamic impact,unidirectional gradient structures exhibit exceptional energy absorption,particularly the unidirectional positive gradient honeycomb structure(UPG-SML)with outstanding mechanical *** angle gradient design plays a crucial role in determining the structure's stability and deformation mode during *** interlayer separations result in a more pronounced negative Poisson's ratio effect and enhance the structure's energy absorption *** findings provide a foundation for the rational design and selection of seismic protection structures in different strain rate impact environments.

关键词： Negative Poisson's ratio Gradient honeycomb structure Quasi-static compression Dynamic impact Titanium alloy

Resource Trading and Miner Competition in Wireless Blockchain Networks with Edge Computing

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China Communications 2023年第11期20卷 187-201页

作者： yuchen Zhou Jian Chen Lu Lyu Bingtao He The State Key Laboratory of Integrated Service Networks Xidian UniversityXi’an 710071China

To promote the application of edge com-puting in wireless blockchain networks,this paper presents a business ecosystem,where edge comput-ing is introduced to assist blockchain users in imple-menting the mining *** paper exploits re-source trading and miner competition to enable se-cure and efficient transactions in the presented busi-ness *** resource trading problem is for-mulated as a Stackelberg game between miner candi-dates and edge computing servers,where computing,caching,and communication resources are jointly op-timized to maximize the potential *** of-floading is introduced to further enhance the system performance when compared with the existing *** analyze the existence and uniqueness of the Nash equilibrium and Stackelberg *** on the optimization result,winners are selected from the set of miner candidates by bidding and constitute the mining *** results demonstrate that the proposal is able to improve the social welfare of blockchain miners,thus stimulating more blockchain users to join the mining network.

关键词： blockchain edge computing miner com-petition resource trading social welfare

Influence of H_(2)S and NH_(3) on biogas dry reforming using Ni catalyst:a study on single and synergetic effect

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Frontiers of Environmental Science & Engineering 2023年第3期17卷 63-74页

作者： yuchen Gao Jianguo Jiang Yuan Meng Tongyao Ju Siyu Han School of Environmental Science and Engineering Tiangong UniversityTianjin 300387China School of Environment Tsinghua UniversityBeijing 100084China

Biogas is a renewable biomass energy source mainly composed of CH4 and CO_(2).Dry reforming is a promising technology for the high-value utilization of *** impurity gases in biogas can not be completely removed after pretreatment,which may affect the performance of dry *** this study,the influence of typical impurities H_(2)S and NH_(3) on dry reforming was studied using Ni/MgO *** results showed that low concentration of H_(2)S in biogas could cause serious deactivation of *** results including EDS,XPS and TOF-SIMS confirmed the adsorption of sulfur on the catalyst surface,which was the cause of catalyst *** used air calcination method to regenerate the sulfur-poisoned catalysts and found that the regeneration temperature higher than 500℃could help catalyst recover the original ***_(3)in the concentration range of 50–10000 ppm showed a slight inhibitory effect on biogas dry *** decline rate of biogas conversion efficiency increased with the increase of NH_(3) *** was related to the reduction of oxygen activity on catalyst surface caused by NH_(3).The synergetic effect of H_(2)S and NH_(3)in biogas was *** results showed that biogas conversion decreased faster under the coexistence of H_(2)S and NH_(3)than under the effect of H_(2)S alone,so as the surface oxygen activity of *** calcination regeneration could also recover the activity of the deactivated catalyst under the synergetic effect of H_(2)S and NH_(3).

关键词： Biogas Dryreforming Suifur poisoning Ammonia Synergetic effect Hydrogen

Post-disturbance transient stability assessment of power systems towards optimal accuracy-speed tradeoff

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Protection and Control of Modern Power Systems 2018年第1期3卷 203-212页

作者： Chao Ren Yan Xu yuchen Zhang Interdisciplinary Graduate School Nanyang Technological University50 Nanyang AvenueSingapore 639798Singapore School of Electrical and Electronic Engineering Nanyang Technological UniversitySingaporeSingapore School of Electrical Engineering and Telecommunication University of New South WalesSydneyAustralia

The recent development of phasor measurement technique opens the way for real-time post-disturbance transient stability assessment(TSA).Following a disturbance,since the transient instability can occur very fast,there is an urgent need for fast TSA with sufficient *** paper first identifies the tradeoff relationship between the accuracy and speed in post-disturbance TSA,and then proposes an optimal self-adaptive TSA method to optimally balance such *** uses ensemble learning and credible decision-making rule to progressively predict the post-disturbance transient stability status,and models a multi-objective optimization problem to search for the optimal balance between TSA accuracy and *** such optimally balanced TSA performance,the TSA decision can be made as fast as possible while maintaining an acceptable level of *** proposed method is tested on New England 10-machine 39-bus system,and the simulation results verify its high efficacy.

关键词： Ensemble learning Extreme learning machine(ELM) Intelligent system(IS) Multi-objective optimization Transient stability assessment

Observer-based robust high-order fully actuated attitude autopilot design for spinning glide-guided projectiles

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Defence Technology（防务技术） 2024年第4期34卷 282-294页

作者： Wei Wang yuchen Wang Shiwei Chen Yongcang Guo Zhongjiao Shi School of Aerospace Engineering Beijing Institute of TechnologyBeijing 10081China Northwest Industries Group CO. Ltd.Xi'an 710043China

This paper investigates the design of an attitude autopilot for a dual-channel controlled spinning glideguided projectile(SGGP),addressing model uncertainties and external *** on fixed-time stable theory,a disturbance observer with integral sliding mode and adaptive techniques is proposed to mitigate total disturbance effects,irrespective of initial *** introducing an error integral signal,the dynamics of the SGGP are transformed into two separate second-order fully actuated ***,employing the high-order fully actuated approach and a parametric approach,the nonlinear dynamics of the SGGP are recast into a constant linear closed-loop system,ensuring that the projectile's attitude asymptotically tracks the given goal with the desired *** the proposed composite control framework,the ultimately uniformly bounded stability of the closed-loop system is rigorously demonstrated via the Lyapunov *** of the effectiveness of the proposed attitude autopilot design is provided through extensive numerical simulations.

关键词： Spinning glide-guided projectile Attitude control Sliding mode disturbance observer Fixed-time stable theory High-order fully actuated approach