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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

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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

Improvement of Microstructure and Mechanical Properties of Rapid Cooling Friction Stir-welded A1050 Pure Aluminum

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Journal of Wuhan University of Technology(Materials Science) 2024年第1期39卷 134-141页

作者：许楠 LIU Lutao SONG Qining ZHAO Jianhua BAO Yefeng college of Materials Science and engineering Hohai UniversityChangzhou 213200China

Two-mm thick A1050 pure aluminum plates were successfully joined by conventional and rapid cooling friction stir welding(FSW), respectively. The microstructure and mechanical properties of the welded joints were investigated by electron backscatter diffraction characterization, Vickers hardness measurements, and tensile testing. The results showed that liquid CO_(2) coolant significantly reduced the peak temperature and increased the cooling rate, so the rapidly cooled FSW joint exhibited fine grains with a large number of dislocations. The grain refinement mechanism of the FSW A1050 pure aluminum joint was primarily attributed to the combined effects of continuous dynamic recrystallization, grain subdivision, and geometric dynamic recrystallization. Compared with conventional FSW, the yield strength, ultimate tensile strength, and fracture elongation of rapidly cooled FSW joint were significantly enhanced, and the welding efficiency was increased from 80% to 93%. The enhanced mechanical properties and improved synergy of strength and ductility were obtained due to the increased dislocation density and remarkable grain refinement. The wear of the tool can produce several WC particles retained in the joint, and the contribution of second phase strengthening to the enhanced strength should not be ignored.

关键词： aluminum alloy friction stir welding recrystallization microstructure mechanical properties

Constructing hierarchical arrays with core-shell metal oxides@metal coordination polymers for efficient and stable overall water splitting

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Nano Research 2024年第6期17卷 4882-4888页

作者： Shuai Qi Jinlian Liao Kunzhong Chen Senkai Li Jinwen Zhao Tianchi Huang Na Meng Hengpan Yang Qi Hu Chuanxin He college of Chemistry and Environmental engineering Shenzhen UniversityShenzhen 518060China

Developing non-precious metal-based bifunctional electrocatalysts capable for both hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)is essential to achieve efficient water electrolysis for mass hydrogen production,however it remains ***,we report the synthesis of hierarchical nanorod arrays comprising core-shell structured P-doped NiMoO4@NiFe-coordination polymer(denoted as P-NiMoO4@NiFeCP)as bifunctional electrocatalysts for water ***,we systematically investigate the influence of NiFeCP shell thickness on electrocatalytic activity,manifesting the presence of strong interfacial synergetic effect between P-NiMoO4 and NiFeCP for boosting both the HER and *** advantageous hierarchical architectures and unique core-shell structures,optimized P-NiMoO_(4)@NiFeCP-7.3(7.3 is the shell thickness in nm)requires overpotentials of merely 256 and 297 mV to yield a current density of 1000 mA·cm^(−2)for the HER and OER in 1 M KOH,*** importantly,it can serve as a bifunctional electrocatalyst for efficient and sustainable overall water electrolysis,delivering large current densities of 500 and 1000 mA·cm^(−2)at low cell voltages of 1.804 and 1.865 V,along with high stability of over 500 h at 1000 mA·cm−2,demonstrating the great potential of this electrocatalyst towards practical applications.

关键词： hydrogen evolution reaction oxygen evolution reaction overall water splitting non-precious metal-based electrocatalysts core-shell structures

Continuous wave and active Q-switched operation of Watt-level LED-pumped two-rod Nd,Ce:YAG laser

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Chinese Physics B 2024年第7期33卷 361-366页

作者：沈建平芦鹏徐少聪江容容陈阳陈亮邢凤阳 college of Electronic and Optical engineering&college of Flexible Electronics Nanjing University of Posts and TelecommunicationsNanjing 210023China

A high-performance LED-side-pumped two-rod Nd,Ce:YAG laser with continuous-wave(CW) and acousto–optical(A-O) Q-switched operation is demonstrated in this work. A symmetrically shaped flat–flat cavity with two identical LEDside-pumped laser modules is employed for power scalability. In the CW regime, the maximum output average power of laser at 1064 nm is 4.41 W, corresponding to a maximum optical conversion efficiency of 5.3% and a slope efficiency is 12.4%. In the active Q-switched regime, the pulse energy of laser reaches as high as 0.89 m J at a repetition rate of 800 Hz with a pulse width of 457.2 ns, the corresponding highest peak output power is 1.94 k W and the M~2 factor is measured to be about 8.8. To the best of the authors' knowledge, this is the first demonstration and the highest performance of a CW LED-side-pumped two-rod laser Nd,Ce:YAG with Watt-level output reported so far.

关键词： Watt-level LED-pumped CW Nd Ce:YAG actively Q-switched operation

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Online task planning method of anti-ship missile based on rolling optimization

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Journal of Systems engineering and Electronics 2024年第3期35卷 720-731页

作者： LU Faxing DAI Qiuyang YANG Guang JIA Zhengrong college of Weaponry engineering Naval University of EngineeringWuhan 430033China

Based on the wave attack task planning method in static complex environment and the rolling optimization framework, an online task planning method in dynamic complex environment based on rolling optimization is proposed. In the process of online task planning in dynamic complex environment,online task planning is based on event triggering including target information update event, new target addition event, target failure event, weapon failure event, etc., and the methods include defense area reanalysis, parameter space update, and mission re-planning. Simulation is conducted for different events and the result shows that the index value of the attack scenario after re-planning is better than that before re-planning and according to the probability distribution of statistical simulation method, the index value distribution after re-planning is obviously in the region of high index value, and the index value gap before and after re-planning is related to the degree of posture change.

关键词： target allocation of anti-ship missile defense area rolling optimization task re-planning

Bifunctional core–shell co-catalyst for boosting photocatalytic CO_(2) reduction to CH_(4)

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Nano Research 2024年第3期17卷 1259-1266页

作者： Fangxu Dai Mingming Zhang Jishu Han Zhenjiang Li Shouhua Feng Jun Xing Lei Wang Key Laboratory of Eco-chemical engineering Ministry of EducationCollege of Chemistry and Molecular EngineeringQingdao University of Science and TechnologyQingdao 266042China college of Materials Science and engineering Qingdao University of Science and TechnologyQingdao 266042China college of Environment and Safety engineering Qingdao University of Science and TechnologyShandong Engineering Research Center for Marine Environment Corrosion and Safety ProtectionQingdao 266042China

Solar-light-driven CO_(2) reduction CO to CH_(4) and C2H6 is a complex process involving multiple elementary reactions and energy ***,achieving high CH_(4) activity and selectivity remains a significant ***,we integrate bifunctional Cu2O and Cu-MOF(MOF=metal-organic framework)core–shell co-catalysts(Cu2O@Cu-MOF)with semiconductor TiO_(2).Experiments and theoretical calculations demonstrate that Cu2O(Cu+facilitates charge separation)and Cu-MOF(Cu2+improves the CO_(2) adsorption and activation)in the core–shell structure have a synergistic effect on photocatalytic CO_(2) reduction,reducing the formation barrier of the key intermediate*COOH and**** photocatalyst exhibits high CH_(4) yield(366.0μmol·g^(-1)·h^(-1)),efficient electron transfer(3283μmol·g^(-1)·h^(-1))and hydrocarbon selectivity(95.5%),which represents the highest activity of Cu-MOF-based catalysts in photocatalytic CO_(2) reduction *** work provides a strategy for designing efficient photocatalysts from the perspective of precise regulation of components.

关键词： bifunctional co-catalyst core–shell photocatalytic CO_(2)reduction

Deep unfolding based channel estimation for wideband terahertz near-field massive MIMO systems

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Frontiers of Information Technology & Electronic engineering 2024年第8期25卷 1162-1172页

作者： Jiabao GAO Xiaoming CHEN Geoffrey Ye LI college of Information Science and Electronic engineering Zhejiang UniversityHangzhou 310027China Department of Electrical and Electronic engineering Imperial College LondonLondon SW 2BUUK

The combination of terahertz and massive multiple-input multiple-output(MIMO)is promising for meeting the increasing data rate demand of future wireless communication systems thanks to the significant band-width and spatial degrees of ***,unique channel features,such as the near-field beam split effect,make channel estimation particularly challenging in terahertz massive MIMO *** one hand,adopting the conventional angular domain transformation dictionary designed for low-frequency far-feld channels will result in degraded channel sparsity and destroyed sparsity structure in the transformed *** the other hand,most existing compressive sensing based channel estimation algorithms cannot achieve high performance and low complexity *** alleviate these issues,in this study,we first adopt frequency-dependent near-field dictionaries to maintain good channel sparsity and sparsity structure in the transformed domain under the near-field beam split ***,a deep unfolding based wideband terahertz massive MIMO channel estimation algorithm is *** each iteration of the approximate message passing-sparse Bayesian learning algorithm,the optimal update rule is learned by a deep neural network(DNN),whose architecture is customized to effectively exploit the inherent channel ***,a mixed training method based on novel designs of the DNN architecture and the loss function is developed to effectively train data from different system *** results validate the superiority of the proposed algorithm in terms of performance,complexity,and robustness.

关键词： Terahertz Massive MIMO Channel estimation Deep learning

Application of deep learning for informatics aided design of electrode materials in metal-ion batteries

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Green Energy & Environment 2024年第5期9卷 877-889页

作者： Bin Ma Lisheng Zhang Wentao Wang Hanqing Yu Xianbin Yang Siyan Chen Huizhi Wang Xinhua Liu School of Transportation Science and engineering Beihang UniversityBeijing102206China college of Automotive engineering Jilin UniversityChangchun130022China Department of Mechanical engineering Imperial College LondonLondonSW72BXUK

To develop emerging electrode materials and improve the performances of batteries,the machine learning techniques can provide insights to discover,design and develop battery new materials in high-throughput *** this paper,two deep learning models are developed and trained with two feature groups extracted from the Materials Project datasets to predict the battery electrochemical performances including average voltage,speciﬁc capacity and speciﬁc *** deep learning models are trained with the multilayer perceptron as the *** Bayesian optimization and Monte Carlo methods are applied to improve the prediction accuracy of *** on 10 types of ion batteries,the correlation coefﬁcients are maintained above 0.9 compared to DFT calculation results and the mean absolute error of the prediction results for voltages of two models can reach 0.41 V and 0.20 V,*** electrochemical performance prediction times for the two trained models on thousands of batteries are only 72.9 ms and 75.7 ***,the two deep learning models are applied to approach the screening of emerging electrode materials for sodium-ion and potassium-ion *** work can contribute to a high-throughput computational method to accelerate the rational and fast materials discovery and design.

关键词： Cathode materials Material design Electrochemical performance prediction Deep learning Metal-ion batteries

The influences of perforating phase and bedding planes on the fracture deflection in laminated shale

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Petroleum Science 2024年第2期21卷 1221-1230页

作者： Ming-Zhe Gu Mao Sheng Xiao-Ying Zhuang Xin-Yi Li Gen-Sheng Li National Key Laboratory of Petroleum Resources and engineering China University of PetroleumBeijing102249China college of Petroleum engineering China University of PetroleumBeijing102249China college of Civil engineering Tongji UniversityShanghai200092China

The perforating phase leads to complex and diverse hydraulic fracture propagation behaviors in laminated shale formations. In this paper, a 2D high-speed imaging scheme which can capture the interaction between perforating phase and natural shale bedding planes was proposed. The phase field method was used to simulate the same conditions as in the experiment for verification and hydraulic fracture propagation mechanism under the competition of perforating phase and bedding planes was *** results indicate that the bedding planes appear to be no influence on fracture propagation while the perforating phase is perpendicular to the bedding planes, and the fracture propagates along the perforating phase without deflection. When the perforating phase algins with the bedding planes, the fracture initiation pressure reserves the lowest value, and no deflection occurs during fracture propagation. When the perforating phase is the angle 45°, 60°and 75°of bedding planes, the bedding planes begin to play a key role on the fracture deflection. The maximum deflection degree is reached at the perforating phase of75°. Numerical simulation provides evidence that the existence of shale bedding planes is not exactly equivalent to anisotropy for fracture propagation and the difference of mechanical properties between different shale layers is the fundamental reason for fracture deflection. The findings help to understand the intrinsic characteristics of shale and provide a theoretical basis for the optimization design of field perforation parameters.

关键词： Shale Propagation Perforating Bedding Structure