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Tetrathiafulvalene esters with high redox potentials and improved solubilities for non-aqueous redox flow battery applications

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Green Energy & Environment 2024年第5期9卷 899-908页

作者： weikang Hu Jiaqi Xu Nanjie Chen Zongcai Deng Yuekun lai Dongyang Chen College of Materials Science and Engineering Fuzhou UniversityFuzhou350116China College of Chemical Engineering Fuzhou UniversityFuzhou350116China

The exploitation of high performance redox-active substances is critically important for the development of non-aqueous redoxﬂow ***,three tetrathiofulvalene(TTF)derivatives with different substitution groups,namely TTF diethyl ester(TTFDE),TTF tetramethyl ester(TTFTM),and TTF tetraethyl ester(TTFTE),are prepared and their energy storage properties are *** has been found that the redox potential and solubility of these TTF derivatives in conventional carbonate electrolytes increases with the number of ester *** battery with a catholyte of 0.2 mol L^(-1) of TTFTE delivers a speciﬁc capacity of more than 10 Ah L^(-1) at the current density of 0.5 C with two discharge voltage platforms locating at as high as 3.85 and 3.60 V ***/Liþ.Its capacity retention can be improved from 2.34 Ah L^(-1) to 3.60 Ah L^(-1) after 100 cycles by the use of an anion exchange membrane to block the crossover of TTF *** excellent cycling stability of the TIF esters is supported by their well-delocalized electrons,as revealed by the density function theory ***,the introduction of more and larger electron-withdrawing groups is a promising strategy to simultaneously increase the redox-potential and solubility of redox-active ma-terials for non-aqueous redoxﬂow batteries.

关键词： Non-aqueous redox flow batteries Tetrathiofulvarene Redox potential Solubility Substituent effect

Preheating-assisted solid-state friction stir repair of Al-Mg-Si alloy plate at different rotational speeds

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International Journal of Minerals,Metallurgy and Materials 2024年第4期31卷 725-736页

作者： Hui wang Yidi Li Ming Zhang wei Gong Ruilin lai Yunping Li State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China Research Institute of Light Alloy Central South UniversityChangsha 410083China

Additive friction stir deposition(AFSD)is a novel structural repair and manufacturing technology has become a research hotspot at home and abroad in the past five *** this work,the microstructural evolution and mechanical performance of the Al-Mg-Si alloy plate repaired by the preheating-assisted AFSD process were *** evaluate the tool rotation speed and substrate preheating for repair quality,the AFSD technique was used to additively repair 5 mm depth blind holes on 6061 aluminum alloy *** results showed that preheat-assisted AFSD repair significantly improved joint bonding and joint strength compared to the control non-preheat substrate ***,increasing rotation speed was also beneficial to improve the metallurgical bonding of the interface and avoid volume *** preheating conditions,the UTS and elongation were positively correlated with rotation *** the process parameters of preheated substrate and tool rotation speed of 1000 r/min,defect-free specimens could be obtained accompanied by tensile fracture occurring in the substrate rather than the repaired *** UTS and elongation reached the maximum values of 164.2MPa and 13.4%,which are equivalent to 99.4%and 140%of the heated substrate,respectively.

关键词： additive friction stir deposition structural repair tool rotation speed Al alloy

First-principles study on the electronic structure of Pb_(10−x)Cu_(x)(PO_(4))_(6)O(x=0,1)

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Journal of Materials Science & Technology 2024年第4期171卷 66-70页

作者： Junwen lai Jiangxu Li Peitao Liu Yan Sun Xing-Qiu Chen Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

Recently,Lee et *** the experimental discovery of room-temperature ambient-pressure super-conductivity in a Cu-doped lead-apatite(LK-99)(arXiv:2307.12008,arXiv:2307.12037).Remarkably,the claimed superconductivity can persist up to 400 K at ambient *** the experimental im-plication,the electronic structure of LK-99 has not yet been ***,we investigate the electronic structures of LK-99 and its parent compound using first-principles calculations,aiming to elucidate the doping effects of *** results reveal that the parent compound Pb_(10)(PO_(4))_(6)O is an insulator,while Cu doping induces an insulator-metal transition and thus volume *** band structures of LK-99 around the Fermi level are featured by a half-filled flat band and a fully-occupied flat *** two very flat bands arise from both the 2p orbitals of 1/4-occupied O atoms and the hybridization of the 3d orbitals of Cu with the 2p orbitals of its nearest-neighboring O ***,we observe four van Hove singularities on these two flat ***,we show that the flat band structures can be tuned by including electronic correlation effects or by doping different *** find that among the considered doping elements(Ni,Cu,Zn,Ag,and Au),both Ni and Zn doping result in the gap opening,whereas Au exhibits doping effects more similar to Cu than *** work establishes a foundation for fu-ture studies to investigate the role of unique electronic structures of LK-99 in its claimed superconducting properties.

关键词： First-principles calculations Density functional theory Electronic structur e Superconductivity Flat bands Strongly correlated electrons

Permanent Magnet Temperature Estimation for PMSMs Using Virtual Position-offset Injection

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CES Transactions on Electrical Machines and Systems 2024年第1期8卷 51-60页

作者： Beichen Ding Yuting Lu Kaide Huang Guodong Feng Chunyan lai IEEE the School of Intelligent Systems Engineering Sun Yat-sen UniversityShenzhen 518107China the Fosan University Foshan 528225China the Department of Electrical and Computer Engineering Concordia UniversityQCCanada

This paper proposes a virtual position-offset injection based permanent magnet temperature estimation approach for permanent magnet synchronous machines(PMSMs). The concept of virtual position-offset injection is mathematically transforming the machine model to a virtual frame with a position-offset. The virtual frame temperature estimation model is derived to calculate the permanent magnet temperature(PMT) directly from the measurements with computation efficiency. The estimation model involves a combined inductance term, which can simplify the establishment of saturation compensation model with less measurements. Moreover, resistance and inverter distorted terms are cancelled in the estimation model, which can improve the robustness to the winding temperature rise and inverter distortion. The proposed approach can achieve simplified computation in temperature estimation and reduced memory usage in saturation compensation. while existing model-based approaches could be affected by either the need of resistance and inverter information or complex saturation compensation. Experiments are conducted on the test machine to verify the proposed approach under various operating conditions.

关键词： PMSM Magnet temperature estimation Virtual position offset injection Inverter nonlinearity

Biomineralization of soil with crude soybean urease using different calcium salts

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1788-1798页

作者： Yajie weng Junjie Zheng Hanjiang lai Mingjuan Cui Xingzhi Ding School of Civil and Hydraulic Engineering Huazhong University of Science and TechnologyWuhan430074China Zijin School of Geology and Mining Fuzhou UniversityFuzhou350108China College of Civil Engineering Fuzhou UniversityFuzhou350116China

Calcium salt is an important contributing factor for calcium-based *** study the effect of calcium salt on soil biomineralization using crude soybean urease,the calcium salts,including the calcium chloride (CaCl_(2)),calcium acetate ((CH_(3)COO)_(2)Ca) and calcium nitrate (Ca(NO_(3))_(2)),were used to prepare the biotreatment solution to carry out the biomineralization tests in this *** series of biomineralization tests in solution and sand column,respectively,were *** electron microscopy (SEM) and X-ray diffraction (XRD) were performed to determine the microscopic characteristics of the precipitated calcium carbonate (CaCO_(3)) *** experimental results indicate that the biomineralization effect is the best for the CaCl2 case,followed by (CH_(3)COO)_(2)Ca,and worst for Ca(NO_(3))_(2) under the test conditions of this study (i.e.1 mol/L of calcium salt-urea).The mechanism for the effect of the calcium salt on the biomineralization of crude soybean urease mainly involves: (1) inhibition of urease activity,and (2) influence on the crystal size and morphology of CaCO_(3).Besides Ca^(2+) ,the anions in solution can inhibit the activity of crude soybean urease,and NO_(3)− has a stronger inhibitory effect on the urease activity compared with both CH_(3)COO^(−) and Cl^(−) .The co-inhibition of Ca^(2+) and NO_(3)− on the activity of urease is the key reason for the worst biomineralization of the Ca(NO_(3))_(2) case in this *** difference in biomineralization between the CaCl_(2) and (CH_(3)COO)_(2) Ca cases is strongly correlated with the crystal morphology of the precipitated CaCO_(3).

关键词： Biomineralization Crude soybean urease Calcium salt Influence mechanism

Small object detection on highways via balance feature fusion and task-specific encoding network

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Optoelectronics Letters 2024年第7期20卷 424-429页

作者： YU Minming CHAN Sixian ZHOU Xiaolong lai Zhounian College of Computer Science and Technology Zhejiang University of TechnologyHangzhou 310023China Hangzhou Xsuan Technology Co. Ltd.Hangzhou 310051China Quzhou University Quzhou 324000China Huzhou Institute of Zhejiang University Huzhou 313002China2

Detecting small objects on highways is a novel research *** to the small pixel of objects on highways,traditional detectors have difficulty in capturing discriminative ***,the imbalance of feature fusion methods and the inconsistency between classification and regression tasks lead to poor detection performance on *** this paper,we propose a balance feature fusion and task-specific encoding network to address these ***,we design a balance feature pyramid network(FPN)to integrate the importance of each layer of feature maps and construct long-range dependencies among them,thereby making the features more *** addition,we present task-specific decoupled head,which utilizes task-specific encoding to moderate the imbalance between the classification and regression *** demonstrated by extensive experiments and visualizations,our method obtains outstanding detection performance on small object detection on highways(HSOD)dataset and AI-TOD dataset.

关键词： network utilize highway

water self-purification via electron donation effect of emerging contaminants arousing oxygen activation over ordered carbonenhanced CoFe quantum dots

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Environmental Science and Ecotechnology 2024年第4期20卷 167-176页

作者： Yuhao Shi Dongxuan Yang Chun Hu lai Lyu Institute of Environ.Res.at Greater Bay Area Key Laboratory forWater Quality and Conservation of the Pearl River DeltaMinistry of EducationGuangzhou UniversityGuangzhou510006China

The release of emerging contaminants(ECs)into aquatic environments poses a significant risk to global water *** oxidation processes(AOPs),while effective in removing ECs,are often resource and ***,we introduce a novel catalyst,CoFe quantum dots embedded in graphene nanowires(CoFeQds@GN-Nws),synthesized through anaerobic *** uniquely features electron-rich and electron-poor micro-regions on its surface,enabling a self-purification mechanism in *** is achieved by harnessing the internal energy of wastewater,particularly the bonding energy of pollutants and dissolved oxygen(DO).It demonstrates exceptional efficiency in removing ECs at ambient temperature and pressure without the need for external oxidants,achieving a removal rate of nearly 100.0%.The catalyst's structure-activity relationship reveals that CoFe quantum dots facilitate an unbalanced electron distribution,forming these *** leads to a continuous electrondonation effect,where pollutants are effectively cleaved or ***,DO is activated into superoxide anions(O_(2)^(·-)),synergistically aiding in pollutant *** approach reduces resource and energy demands typically associated with AOPs,marking a sustainable advancement in wastewater treatment technologies.

关键词： Quantum dots Emerging contaminants removal Self-purification system Dissolved oxygen

Electrospun carbon nanofiber-supported V_(2)O_(3) with enriched oxygen vacancies as a free-standing high-rate anode for an all-vanadium-based full battery

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Carbon Energy 2024年第9期6卷 15-28页

作者： Qi lai Bincen Yin Yu Dou Qing Zhang Yunhai Zhu Yingkui Yang School of Chemistry and Materials Science South-Central Minzu UniversityWuhanChina State Key Laboratory of New Textile Materials and Advanced Processing Technologies Wuhan Textile UniversityWuhanChina

Synergistic regulation of hierarchical nanostructures and defect engineering is effective in accelerating electron and ion transport for metal oxide ***,carbon nanofiber-supported V_(2)O_(3) with enriched oxygen vacancies(OV-V_(2)O_(3)@CNF)was fabricated using the facile electrospinning method,followed by thermal *** from the traditional particles embedded within carbon nanofibers or irregularly distributed between carbon nanofibers,the free-standing OV-V_(2)O_(3)@CNF allows for V_(2)O_(3) nanosheets to grow vertically on one-dimensional(1D)carbon nanofibers,enabling abundant active sites,shortened ion diffusion pathway,continuous electron transport,and robust structural ***,density functional theory calculations confirmed that the oxygen vacancies can promote intrinsic electron conductivity and reduce ion diffusion energy ***,the OV-V_(2)O_(3)@CNF anode delivers a large reversible capacity of 812 mAh g^(-1) at 0.1 A g^(-1),superior rate capability(405 mAh g^(-1) at 5 A g^(-1)),and long cycle life(378 mAh g^(-1) at 5 A g^(-1) after 1000 cycles).Moreover,an all-vanadium full battery(V2O5//OV-V_(2)O_(3)@CNF)was assembled using an OV-V_(2)O_(3)@CNF anode and a V2O5 cathode,which outputs a working voltage of 2.5 V with high energy density and power density,suggesting promising practical *** work offers fresh perspectives on constructing hierarchical 1D nanofiber electrodes by combining defect engineering and electrospinning technology.

关键词： electrospun electrode full battery oxygen vacancy vanadium trioxide

Volume-complementary bipolar layered oxide enables stable symmetric sodium-ion batteries

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Nano Research 2024年第5期17卷 4125-4133页

作者： Bo Peng Feng wang Nazir Ahmad lai Yu Shenghua Chen Genqiang Zhang School of Materials Science and Engineering Key Laboratory of Efficient Conversion and Solid-state Storage of Hydrogen and Electricity of Anhui ProvinceAnhui University of TechnologyMa’anshan 243002China Hefei National Research Center for Physical Sciences at the Microscale Chinese Academy of Sciences(CAS)Key Laboratory of Materials for Energy ConversionDepartment of Materials Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026China National Innovation Platform(Center)for Industry-Education Integration of Energy Storage Technology School of Chemical Engineering and TechnologyXi’an Jiaotong UniversityXi’an 710049China

The commercialization of sodium-ion batteries is based on developing low-cost,highly stable,and safe cathode and anode ***,the promising hard carbon anode and layered oxide cathode suffer from low sodium-embedded potential near 0.1 V and severe phase transitions,which cause safe problem and short lifespan,***,we design a low-strain bipolar P2-Na_(0.7)Ni_(0.25)Fe_(0.2)Ti_(0.55)O_(2) to solve the mentioned obstacles,whereas(Ni,Fe)and Ti provide charge compensation when it is used as cathode and anode,*** is revealed that the bipolar layered oxide undergoes solid-solution reaction when used as cathode or anode,and exhibits volume-complementary feature in a sodium-ion full-cell,as identified by in-situ X-ray ***,the safe symmetric sodium-ion full-cell exhibits excellent cyclic stability with 91.7%capacity retention after 200 *** work will provide a new horizon for designing safe and stable sodium-ion batteries.

关键词： sodium-ion batteries bipolar layered oxides solid-solution reaction volume complementation symmetric battery