检索结果-南通市图书馆

Nano Research 2024年第4期17卷 2308-2319页

作者： Gang Wang Longchao Sun Wanyi Liu Haijuan Zhan Shuxian Bi college of Chemistry and Chemical engineering Ningxia UniversityYinchuan 750021China

A scalable strategy for the convenient and rapid preparation of nitrogen-doped carbon-coated iron-based alloy catalysts was *** controlling the type and amount of metal salts in the precursor,various types of nitrogen-doped carbon-coated alloy catalysts can be prepared in a targeted ***_(2)Ni2@CN materials with small particle sizes and relatively homogeneous basic sites showed promising results in the N-alkylation reaction of benzyl alcohol with aniline(optimum yield:99%).It is worth noting that the catalyst can also be magnetically separated and recovered after the reaction,and its performance can be regenerated through simple ***,it was confirmed by kinetic experiments that the activation of C–H at the benzyl alcohol benzylic position is the rate-determining step(RDS).According to density flooding theory calculations,Fe_(2)Ni2@CN catalysts require less energy than other materials(Fe@CN and Ni@CN)for the RDS(dehydrogenation reaction)*** N-alkylation reactions are more easily carried out on Fe_(2)Ni2@CN catalysts,which may be the reason for the best catalytic activity of Fe-Ni alloy *** carbon-coated alloy materials will show great potential in more types of heterogeneous catalysis.

关键词： iron-nickel alloy catalyst N-alkylation reaction magnetic separation reaction path dehydrogenation reaction

Smart beam via electrically addressing the dye-doped and polymer-stabilized cholesteric liquid crystals

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Optics Letters 2024年第5期22卷 111-116页

作者：彭程徐春庭胡伟 college of engineering and Applied Sciences Nanjing UniversityNanjing 210023China

Smart beams play a vital role in modern intelligent vehicles and have recently attracted significant attention.A spatial light modulator with high optical efficiency,low cost,and compact size is crucial for designing smart ***,we mix cholesteric liquid crystals with dichroic black dye and a *** UV polymerization,the sample exhibits a low driving voltage of 26 V,a high transmittance of over 70%,and an On-off ratio over 280,thanks to the joint contribution of both the absorption and the scattering effect.A smart beam device is demonstrated by electrically addressing the dye-doped and polymer-stabilized cholesteric liquid crystal with pixelated *** patterns with arbitrary designs are projected *** switching time reaches several tens of *** strategy brings new designs to intelligent vehicles and may also inspire applications in public information displays,advertising,and even AR/VR displays.

关键词： cholesteric liquid crystal spatial light modulation smart beam dye guest-host effect

Distributed dynamic task allocation for unmanned aerial vehicle swarm systems:A networked evolutionary game-theoretic approach

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第6期37卷 182-204页

作者： Zhe ZHANG Ju JIANG Haiyan XU Wen-An ZHANG college of Automation engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106China college of Economics and Management Nanjing University of Aeronautics and AstronauticsNanjing 211106China college of Information engineering Zhejiang University of TechnologyHangzhou 310023China

Task allocation is a key aspect of Unmanned Aerial Vehicle(UAV)swarm collaborative *** an continuous increase of UAVs’scale and the complexity and uncertainty of tasks,existing methods have poor performance in computing efficiency,robustness,and realtime allocation,and there is a lack of theoretical analysis on the convergence and optimality of the *** paper presents a novel intelligent framework for distributed decision-making based on the evolutionary game theory to address task allocation for a UAV swarm system in uncertain scenarios.A task allocation model is designed with the local utility of an individual and the global utility of the ***,the paper analytically derives a potential function in the networked evolutionary potential game and proves that the optimal solution of the task allocation problem is a pure strategy Nash equilibrium of a finite strategy ***,a PayOff-based Time-Variant Log-linear Learning Algorithm(POTVLLA)is proposed,which includes a novel learning strategy based on payoffs for an individual and a time-dependent Boltzmann *** former aims to reduce the system’s computational burden and enhance the individual’s effectiveness,while the latter can ensure that the POTVLLA converges to the optimal Nash equilibrium with a probability of *** simulation results show that the approach is optimal,robust,scalable,and fast adaptable to environmental changes,even in some realistic situations where some UAVs or tasks are likely to be lost and increased,further validating the effectiveness and superiority of the proposed framework and algorithm.

关键词： Task allocation Unmanned Aerial Vehicles(UAV) Game theory Log-linear learning Distributed optimization algorithm

Fluid-structure interaction simulation of dynamic response and wake of floating offshore wind turbine considering tower shadow effect

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2024年第8期40卷 67-84页

作者： Songyang Liu Zhiqiang Xin Lei Wang Zhiming Cai college of Mechanics and engineering Science HoHai UniversityNanjing211100China

The comprehensive numerical simulation of the tower shadow effect on floating offshore wind turbines(FOWTs),an area less explored compared to fixed-bottom wind turbines,is presented in this *** atmospheric boundary layer inflow and the joint north sea wave project random wave are used as the operating conditions for *** combination of computational fluid dynamics(CFD)software simulator for wind farm applications and turbine simulation tool OpenFAST is used to implement fluid-structure interaction *** output power,platform motion,wake velocity deficit and vortex structures are analyzed to reveal the influence of the tower shadow effect on the *** results indicate that due to the fluctuation caused by the turbulent wind and the floating platform motion,the tower shadow effect of FOWT is less significant for its periodic power decay than that of fixed-bottom wind *** according to the velocity deficit analysis,the influence area of the tower shadow effect on the wake is mainly in the near wake region.

关键词： Floating offshore wind turbine Tower shadow effect Atmospheric boundary layer inflow JONSWAP wave Wind turbine wake

Data-driven Distributionally Adjustable Robust Chance-constrained DG Capacity Assessment

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 115-127页

作者： Masoume Mahmoodi Seyyed Mahdi Noori Rahim Abadi Ahmad Attarha Paul Scott Lachlan Blackhall the college of engineering and Computer Science The Australian National UniversityCanberraAustralia

Moving away from fossil fuels towards renewable sources requires system operators to determine the capacity of distribution systems to safely accommodate green and distributed generation(DG).However,the DG capacity of a distribution system is often underestimated due to either overly conservative electrical demand and DG output uncertainty modelling or neglecting the recourse capability of the available *** improve the accuracy of DG capacity assessment,this paper proposes a distributionally adjustable robust chance-constrained approach that utilises uncertainty information to reduce the conservativeness of conventional robust *** proposed approach also enables fast-acting devices such as inverters to adjust to the real-time realisation of uncertainty using the adjustable robust counterpart *** achieve a tractable formulation,we first define uncertain chance constraints through distributionally robust conditional value-at-risk(CVaR),which is then reformulated into convex quadratic *** subsequently solve the resulting large-scale,yet convex,model in a distributed fashion using the alternating direction method of multipliers(ADMM).Through numerical simulations,we demonstrate that the proposed approach outperforms the adjustable robust and conventional distributionally robust approaches by up to 15%and 40%,respectively,in terms of total installed DG capacity.

关键词： Distributed generation(DG)capacity assessment distributionally robust optimisation chance-constrained optimisation distribution system

Cost-effective fabrication of liquid metals via a laser induced graphene stamp for highly-stretchable integrated optoelectronics

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第8期17卷 7603-7613页

作者： Weiqi Sun Li Xiang Zebang Luo Hui Wang Dong Li Anlian Pan college of Materials Science and engineering Hunan UniversityChangsha 410082China

Stretchable electronics have found widespread applications in various fields such as wearable electronics,soft robots,and *** an important promising alternative of traditional rigid conductors,liquid metals have demonstrated immense potential to provide high conductivity and stretchability for the stretchable electronic ***,limited by their fluidity and high surface tension,challenges remain in achieving liquid metal patterns with low-cost,high-precision,large-scale,and complex ***,a fabrication technique was proposed based on laser-induced graphene(LIG)stamps to enable liquid metal self-selectively adhere to *** metal patterns could thus be achieved in different designed geometries and could be transferred onto stretchable *** liquid metal patterns exhibit exceptional electrical conductivity(3.24×10^(6)S/m even under 1000%strain),high stretchability(1000%strain,maximum of 2500%),small resistance changes under significant deformations(with a quality factor of 62.5 under 1000%strain),and high resolution(down to 50μm).Utilizing the patterned liquid metals,a stretchable integrated multifunctional optoelectronic system was demonstrated,encompassing a stretchable display matrix,a pressure sensor array,a wireless powering coil,and cardiovascular sensors,which further highlight the remarkable application potential of liquid metals in optoelectronic user-interaction and advanced physiological monitoring.

关键词： liquid metal wettability selective adhesion transfer printing stretchable electronics

engineering the spectra of photon triplets generated from micro/nanofiber

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第3期33卷 408-414页

作者：瞿川郭东琴李笑笑刘振旗赵义张胜海卫正统 The college of Basic Department Information Engineering UniversityZhengzhou 450000China

Quantum light sources are the core resources for photonics-based quantum information *** investigate the spectral engineering of photon triplets generated by third-order spontaneous parametric down-conversion in micro/*** phase mismatching at one-third pump frequency gives rise to non-degenerate photon triplets,the joint spectral intensity of which has an elliptical locus with a fixed eccentricity of√6/***,we propose a frequency-division scheme to separate non-degenerate photon triplets into three channels with high heralding efficiency for the first *** an appropriate pump wavelength can compensate for the fabrication errors of micro/nanofiber and also generate narrowband,non-degenerate photon triplet sources with a high signal-to-noise ***,the long-period micro/nanofiber grating introduces a new controllable degree of freedom to tailor phase matching,resulting from the periodic oscillation of *** this scheme,the wavelength of photon triplets can be flexibly tuned using quasi-phase *** study the generation of photon triplets from this novel perspective of spectrum engineering,and we believe that this work will accelerate the practical implementation of photon triplets in quantum information processing.

关键词： photon triplets micro/nanofiber spectrum engineering

Promoting electrocatalytic nitrogen reduction to ammonia via dopant boron on two-dimensional materials

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第10期43卷 5117-5125页

作者： Ya-Hui Cui Wen-Cheng Ouyang Ai-Jun Gao Chang-Yuan Yu Li-Peng Zhang State Key Laboratory of Organic-Inorganic Composites College of Chemical EngineeringBeijing University of Chemical Technology college of Materials Science and engineering Beijing University of Chemical Technology college of Life Science and Technology Beijing University of Chemical Technology

Electrocatalytic nitrogen reduction reaction(NRR) is a key process for producing energy efficient and environment friendly ammonia. Boron-doped two-dimensional materials are highly promising as NRR ***, the interaction between doped boron and matrix materials on NRR catalytic performance is still unclear,which is limiting the development of catalysts containing boron for NRR. Here, NRR on different boron-doped twodimensional(2D) materials was explored by first principle theory. It is found that adsorption energy of intermediate*NNH(E*NNH) can be used as a descriptor to characterize the catalytic activity for NRR. Boron-adsorbed black phosphorus(B-BP) is demonstrated showing excellent NRR catalytic activity and suppressing hydrogen evolution reaction. It is disclosed that the excellent catalytic performance of boron-doped structures comes from a proper quantitatively electron transfer(0.8e) between nitrogen in*NNH and the active site boron atom. This work not only established a descriptor for NRR catalytic activity on B-doped 2D materials, but also screened out a potential NRR catalyst. More importantly, the intrinsic reason and mechanism of high catalytic activity of boron-doped structures were proposed. This work provides a design principle for exploring high-performance NRR electrocatalysts containing boron.

关键词： Boron-doped two-dimensional materials Density functional theory Descriptor Electrocatalytic nitrogen reduction reaction

High-efficiency preparation of multifunctional conjugated electrospun graphene doped PVDF/CF yarns for energy harvesting and human movement monitoring in TENG textile

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第5期17卷 4478-4488页

作者： Ting Yang Chengwei Wan Xiaoyu Zhang Tong Liu Li Niu Jian Fang Yuqing Liu college of Textile and Clothing engineering Soochow UniversitySuzhou 215123China

Portable power is an effective solution to realize self-powered sensors for wearable devices,promoting future sustainable ***-based triboelectric nanogenerators(M-TENGs)have emerged as a promising technology for harvesting biomechanical energy from human motion owing to their advantages,such as simple structure,lightweight design,and efficient energy ***,the poor durability,low adaptability,and un-washability of two-dimensional membrane materials have largely hindered their application in wearable *** this study,we propose a sheath-core polyvinylidene fluoride(PVDF)/graphene(G)-carbon fiber(CF)yarn fabricated via conjugate electrospinning,comprising a commercial CF core and an electrospun graphene-doped PVDF sheath,which improves the fatigue resistance of electrospun nanofiber films under prolonged friction and keeps a high degree of *** resulting electronic textile,woven with the large-scale electrospun PVDF/G-CF yarn,demonstrates a remarkable power density of 25.5 mW·m^(-2).The tight distribution of PVDF/G nanofibers on the textile surface ensures excellent softness,washability,and ***,the electrospun PVDF/G-CF textile exhibits significant potential in pressure sensing,self-powered operation,and motion detection,making it highly suitable for wearable electronics applications.

关键词： yarn-based triboelectric nanogenerator(TENG) graphene polyvinylidene fluoride(PVDF) conjugated-electrospinning multifunctional

Viscosity and structure of CaO-BaO-SiO_(2)-Al_(2)O_(3)-based mold slags for continuous casting of high titanium steel with different Tio2 absorption

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第8期31卷 1936-1946页

作者： Ya-tao Cui Xue-you Wang Xu-bin Zhang Qiang-qiang Wang Sheng-ping He college of Materials Science and engineering Chongqing UniversityChongqing 400044China

The effect of TiO_(2) absorption into two different CaO-BaO-SiO_(2)-Al_(2)O_(3)-based mold slags from the steel plant on the viscosity,melting performance and microstructure of slags was investigated through the measurement of the viscosity-temperature relationship,melting temperature and Raman *** parameter of the number of non-bridging oxygen per tetrahedrally-coordinated atom(NBO/T)was also calculated to explain the microstructure variation of molten slags with different TiO_(2) *** variation of the actual slag consumption and the depth of the liquid slag in mold was explained through the comparison of the viscosity and the melting temperature of two different *** viscosity of mold slags(basicity=0.6)decreased from 1.1 to 0.68 Pa s with the increase in the Ti0_(2) absorption from 0 to 10%,while that of slags(basicity=0.7)decreased from 0.76 to 0.56 Pa s with the Ti0_(2) absorption from 0 to 6%.The activation energy of both two groups of slags had the tendency to decrease with the increasing TiO_(2) *** network structure of both two groups of slags measured by the Raman spectra showed that the fraction of complex structure units(Q^(1),Q^(2),Q^(3) and A1-O-Al)decreased and simple structure units(Al-O-and Q^(0))increased with the increase in TiO_(2) ***/T also increased with the increase in the TiO2 absorption,indicating that the absorption of TiO_(2) into slags resulted in the destruction of silicate/aluminate ***,the absorption of TiO_(2) into the current CaO-BaO-SiO_(2)-Al_(2)O_(3) mold slags decreased the degree of polymerization of these slags and then led to the decrease of viscosity.

关键词： Mold slag Viscosity Melting temperature Slag consumption Liquid slag depth Structure