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Contrastive learning for nested Chinese Named Entity Recognition via template words 被引量:1
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作者 Yuke Wang Qiao Liu +3 位作者 Tingting Dai Junjie Lang Ling Lu Yinong Chen 《CAAI Transactions on Intelligence Technology》 2025年第2期450-459,共10页
Existing Chinese named entity recognition(NER)research utilises 1D lexicon-based sequence labelling frameworks,which can only recognise flat entities.While lexicons serve as prior knowledge and enhance semantic inform... Existing Chinese named entity recognition(NER)research utilises 1D lexicon-based sequence labelling frameworks,which can only recognise flat entities.While lexicons serve as prior knowledge and enhance semantic information,they also pose completeness and resource requirements limitations.This paper proposes a template-based classification(TC)model to avoid lexicon issues and to identify nested entities.Template-based classification provides a template word for each entity type,which utilises contrastive learning to integrate the common characteristics among entities with the same category.Contrastive learning makes template words the centre points of their category in the vector space,thus improving generalisation ability.Additionally,TC presents a 2D tablefilling label scheme that classifies entities based on the attention distribution of template words.The proposed novel decoder algorithm enables TC recognition of both flat and nested entities simultaneously.Experimental results show that TC achieves the state-ofthe-art performance on five Chinese datasets. 展开更多
关键词 Chinese NER classification GENERALIZATION syntactic dependency template
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Prussian Blue Analogue‑Templated Nanocomposites for Alkali‑Ion Batteries:Progress and Perspective
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作者 Jian‑En Zhou Yilin Li +1 位作者 Xiaoming Lin Jiaye Ye 《Nano-Micro Letters》 SCIE EI CAS 2025年第1期216-261,共46页
Lithium-ion batteries(LIBs)have dominated the portable electronic and electrochemical energy markets since their commercialisation,whose high cost and lithium scarcity have prompted the development of other alkali-ion... Lithium-ion batteries(LIBs)have dominated the portable electronic and electrochemical energy markets since their commercialisation,whose high cost and lithium scarcity have prompted the development of other alkali-ion batteries(AIBs)including sodium-ion batteries(SIBs)and potassium-ion batteries(PIBs).Owing to larger ion sizes of Na^(+)and K^(+)compared with Li^(+),nanocomposites with excellent crystallinity orientation and well-developed porosity show unprecedented potential for advanced lithium/sodium/potassium storage.With enticing open rigid framework structures,Prussian blue analogues(PBAs)remain promising self-sacrificial templates for the preparation of various nanocomposites,whose appeal originates from the well-retained porous structures and exceptional electrochemical activities after thermal decomposition.This review focuses on the recent progress of PBA-derived nanocomposites from their fabrication,lithium/sodium/potassium storage mechanism,and applications in AIBs(LIBs,SIBs,and PIBs).To distinguish various PBA derivatives,the working mechanism and applications of PBA-templated metal oxides,metal chalcogenides,metal phosphides,and other nanocomposites are systematically evaluated,facilitating the establishment of a structure–activity correlation for these materials.Based on the fruitful achievements of PBA-derived nanocomposites,perspectives for their future development are envisioned,aiming to narrow down the gap between laboratory study and industrial reality. 展开更多
关键词 Prussian blue analogues Self-sacrificial template Lithium-ion batteries Sodium-ion batteries Potassium-ion batteries
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Metal‑organic framework‑templated construction of FeOOH@CoMoO_(4)/nickel foam heterostructure for enhanced oxygen evolution reaction
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作者 YANG Shaohua GAO Na'na GONG Yaqiong 《无机化学学报》 北大核心 2025年第10期2175-2185,共11页
Through employing zeolitic imidazolate framework-67(ZIF-67)templates,the straightforward hydrother-mal and electrodeposition methods were applied to synthesize FeOOH@CoMoO_(4)heterostructure attached to the sur-face o... Through employing zeolitic imidazolate framework-67(ZIF-67)templates,the straightforward hydrother-mal and electrodeposition methods were applied to synthesize FeOOH@CoMoO_(4)heterostructure attached to the sur-face of nickel foam(NF).The specific structure of the as-prepared FeOOH@CoMoO_(4)/NF-400s provided pronounced porosity and extensive surface area,enhancing rapid electron transport and exposing abundant active sites to improve catalytic reactions.Furthermore,the introduction of FeOOH,which induces electron transfer from FeOOH to CoMoO_(4),confirms their strong electronic interaction,thereby leading to an accelerated surface catalytic reaction.Consequently,the constructed FeOOH@CoMoO_(4)/NF-400s heterostructure demonstrated exceptional oxygen evolu-tion reaction(OER)activity,requiring an overpotential of 199 mV to deliver the current density of 10 mA·cm^(-2),cou-pled with the superior Tafel slope value of 49.56 mV·dec^(-1)and outstanding stability over 20 h under the current densities of both 10 and 100 mA·cm^(-2). 展开更多
关键词 template sacrifice approach zeolitic imidazolate framework-67 oxygen evolution reaction ELECTROCATALYSTS
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Structure and Photoelectric Properties of β-Ga_(2)O_(3) Nanopores Grown by Pulsed Laser Deposition on AAO Templates
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作者 GE Xuehao JIANG Kai WANG Xianghu 《发光学报》 北大核心 2025年第12期2302-2308,共7页
The wide band gap characteristics of gallium oxide make it very suitable for the preparation of solar-blind ultra-violet photodetectors.The responsivity of ultraviolet photodetectors based on thin films is often low.H... The wide band gap characteristics of gallium oxide make it very suitable for the preparation of solar-blind ultra-violet photodetectors.The responsivity of ultraviolet photodetectors based on thin films is often low.However,nanomaterials have excellent photoelectric properties in device applications due to the high stability brought by high specific surface area and high crystal quality.Here,we successfully depositedβ-Ga_(2)O_(3) nanopores on the double-pass ordered porous AAO tem-plate by PLD.The porous AAO template is used as the growth space of nanomaterials,and the gallium oxide material is filled into the pores of the template to form a nanotube structure.By optimizing the preparation process,the relationship be-tween the performance of gallium oxide nanopores and the growth time was studied in depth.With the increase of growth time,the responsivity of the detector was improved.The rise timeτr=0.7 s,the decay timeτ_(d)=1.3 s,and the responsivity reached 4.63 mA·W^(-1),which was higher than 2.24 mA·W^(-1)of the responsivity of silicon-based gallium oxide nanorods. 展开更多
关键词 β-Ga_(2)O_(3)nanopores AAO template PLD wide bandgap semiconductor materials
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A controllable one-step millisecond synthesis of nanocrystalline mesoporous MgO with template-free by gliding arc plasma for efficient photocatalytic degradation of organic compounds
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作者 Siyuan Zhang Xiaosong Li +5 位作者 Kexin Li Liang Ma Hainig Liu Shengting Li Mingzhe Dong Xiushen Ye 《Journal of Materials Science & Technology》 2025年第27期195-204,共10页
1.Introduction Magnesium oxide(MgO)has attracted considerable attention in recent years due to its economic viability,excellent biocompatibil-ity,chemical stability,and non-toxic,odorless nature[1,2].These inherent pr... 1.Introduction Magnesium oxide(MgO)has attracted considerable attention in recent years due to its economic viability,excellent biocompatibil-ity,chemical stability,and non-toxic,odorless nature[1,2].These inherent properties position it as a promising candidate for various applications. 展开更多
关键词 NANOCRYSTALLINE magnesium oxide photocatalytic degradation gliding arc plasma organic compounds MESOPOROUS template free magnesium oxide mgo
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High quality 6-inch single-crystalline AlN template for E-mode HEMT power device
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作者 Zhiwen Liang Shangfeng Liu +12 位作者 Ye Yuan Tongxin Lu Xiaopeng Li Zirong Wang Neng Zhang Tai Li Xiangdong Li Qi Wang Shengqiang Zhou Kai Kang Jincheng Zhang Yue Hao Xinqiang Wang 《Journal of Semiconductors》 2025年第3期96-101,共6页
In the present work,the high uniform 6-inch single-crystalline AlN template is successfully achieved by high temperature annealing technique,which opens up the path towards industrial application in power device.Moreo... In the present work,the high uniform 6-inch single-crystalline AlN template is successfully achieved by high temperature annealing technique,which opens up the path towards industrial application in power device.Moreover,the outstanding crystalline-quality is confirmed by Rutherford backscattering spectrometry(RBS).In accompanied with the results from X-ray diffraction,the RBS results along both[0001]and[1213]reveal that the in-plane lattice is effectively reordered by high temperature annealing.In addition,the constantΦ_(epi)angle between[0001]and[1213]at different depths of 31.54°confirms the uniform compressive strain inside the AlN region.Benefitting from the excellent crystalline quality of AlN template,we can epitaxially grow the enhanced-mode high electron mobility transistor(HEMT)with a graded AlGaN buffer as thin as only~300 nm.Such an ultra-thin AlGaN buffer layer results in the wafer-bow as low as 18.1μm in 6-inch wafer scale.The fabricated HEMT devices with 16μm-L_(GD)exhibits a threshold voltage(V_(TH))of 1.1 V and a high OFF-state breakdown voltage(V_(BD))over 1400 V.Furthermore,after 200 V high-voltage OFF-state stress,the current collapse is only 13.6%.Therefore,the advantages of both 6-inch size and excellent crystallinity announces the superiority of single-crystalline AlN template in low-cost electrical power applications. 展开更多
关键词 SINGLE-CRYSTALLINE allium nitride template E-mode HEMT
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Effect of Ca addition on microstructure and properties of porous Mg−1Zn−1Sn alloy scaffold prepared via 3D printed Ti template-infiltration casting
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作者 Lei-ting YU Hao LIU +4 位作者 Peng-nan JIANG Shao-yuan LYU Yun ZHAO Wei LI Min-fang CHEN 《Transactions of Nonferrous Metals Society of China》 2025年第4期1137-1154,共18页
The Mg−1Zn−1Sn and Mg−1Zn−1Sn−0.2Ca alloy scaffolds were prepared via infiltration casting using 3D-printed Ti templates to achieve complete and accurate control of the pore structure.The results indicate that the act... The Mg−1Zn−1Sn and Mg−1Zn−1Sn−0.2Ca alloy scaffolds were prepared via infiltration casting using 3D-printed Ti templates to achieve complete and accurate control of the pore structure.The results indicate that the actual porosity and pore size of the prepared P model for each pore size are greater than the designed values.The addition of Ca changes the second phase of the alloy from Mg_(2)Sn to CaMgSn and refines its microstructure.The compressive yield strength and compressive modulus of the Mg−1Zn−1Sn−0.2Ca alloy scaffold reach 32.61 MPa and 0.23 GPa,respectively.The corrosion current density is measured at 14.64μA/cm^(2),with an instantaneous corrosion rate of 0.335 mm/a.Both scaffolds exhibit excellent biocompatibility and no cytotoxicity.Additionally,the antibacterial effects of both alloys on E.coli are greater than 97.81%.These results indicate that Mg alloy scaffolds have great potential for clinical applications. 展开更多
关键词 infiltration casting 3D-printed Ti template mechanical properties corrosion resistance biocompatibility
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Gray Fabric Defect Detection Based on Statistical Template Matching
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作者 LI Saisai YU Haiyan WANG Junhua 《Journal of Donghua University(English Edition)》 2025年第6期594-605,共12页
To address the high cost of online detection equipment and the low adaptability and accuracy of online detection models that are caused by uneven lighting,high noise,low contrast and so on,a block-based template match... To address the high cost of online detection equipment and the low adaptability and accuracy of online detection models that are caused by uneven lighting,high noise,low contrast and so on,a block-based template matching method incorporating fabric texture characteristics is proposed.Firstly,the template image set is evenly divided into N groups of sub-templates at the same positions to mitigate the effects of image illumination,reduce the model computation,and enhance the detection speed,with all image blocks being preprocessed.Then,the feature value information is extracted from the processed set of subtemplates at the same position,extracting two gray-level cooccurrence matrix(GLCM)feature values for each image block.These two feature values are then fused to construct a matching template.The mean feature value of all image blocks at the same position is calculated and used as the threshold for template detection,enabling automatic selection of template thresholds for different positions.Finally,the feature values of the image blocks in the experimental set are traversed and matched with subtemplates at the same positions to obtain fabric defect detection results.The detection experiments are conducted on a platform that simulates a fabric weaving environment,using defective gray fabrics from a weaving factory as the detected objects.The outcomes demonstrate the efficacy of the proposed method in detecting defects in gray fabrics,the mitigation of the impact of uneven external lighting on detection outcomes,and the enhancement of detection accuracy and adaptability. 展开更多
关键词 defect detection gray-level co-occurrence matrix(GLCM) template matching gray fabric feature extraction online detection
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Template-oriented synthesis of boron/nitrogen-rich carbon nanoflake superstructure for high-performance Zn-ion hybrid capacitors
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作者 Chunjiang Jin Fengjiao Guo +4 位作者 Hongyu Mi Nianjun Yang Congcong Yang Xiaqing Chang Jieshan Qiu 《Carbon Energy》 2025年第3期76-90,共15页
The rise of Zn-ion hybrid capacitor(ZHC)has imposed high requirements on carbon cathodes,including reasonable configuration,high specific surface area,multiscale pores,and abundant defects.To achieve this objective,a ... The rise of Zn-ion hybrid capacitor(ZHC)has imposed high requirements on carbon cathodes,including reasonable configuration,high specific surface area,multiscale pores,and abundant defects.To achieve this objective,a template-oriented strategy coupled with multi-heteroatom modification is proposed to precisely synthesize a three-dimensional boron/nitrogen-rich carbon nanoflake-interconnected micro/nano superstructure,referred to as BNPC.The hierarchically porous framework of BNPC shares short channels for fast Zn2+transport,increased adsorption-site accessibility,and structural robustness.Additionally,the boron/nitrogen incorporation effect significantly augments Zn2+adsorption capability and more distinctive pseudocapacitive nature,notably enhancing Zn-ion storage and transmission kinetics by performing the dual-storage mechanism of the electric double-layer capacitance and Faradaic redox process in BNPC cathode.These merits contribute to a high capacity(143.7 mAh g^(-1)at 0.2 A g^(-1))and excellent rate capability(84.5 mAh g^(-1)at 30 A g^(-1))of BNPC-based aqueous ZHC,and the ZHC still shows an ultrahigh capacity of 108.5 mAh g^(-1)even under a high BNPC mass loading of 12 mg cm^(-2).More critically,the BNPC-based flexible device also sustains notable cyclability over 30,000 cycles and low-rate self-discharge of 2.13 mV h-1 along with a preeminent energy output of 117.15 Wh kg^(-1)at a power density of 163.15Wkg^(-1),favoring a creditable applicability in modern electronics.In/ex-situ analysis and theoretical calculations elaborately elucidate the enhanced charge storage mechanism in depth.The findings offer a promising platform for the development of advanced carbon cathodes and corresponding electrochemical devices. 展开更多
关键词 active site density carbon superstructure heteroatom doping MOF template Zn-ion hybrid capacitor
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An enhanced fingerprint template protection scheme based on four-dimensional superchaotic system and dynamic DNA coding
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作者 Baiqiang Hu Jiahui Liu Zhe Liu 《Chinese Physics B》 2025年第7期262-272,共11页
With the rapid development of Internet of things technology,the efficiency of data transmission between devices has been significantly improved.However,the open network environment also poses serious security risks.Th... With the rapid development of Internet of things technology,the efficiency of data transmission between devices has been significantly improved.However,the open network environment also poses serious security risks.This paper proposes an innovative fingerprint template protection scheme,which generates key streams through an improved fourdimensional superchaotic system(4CSCS),uses the space-filling property of Hilbert curves to achieve pixel scrambling,and introduces dynamic DNA encoding to improve encryption.Experimental results show that this scheme has a large key space 2^(528),encrypts image information entropy of more than 7.9970,and shows excellent performance in defending against statistical attacks and differential attacks.Compared with existing methods,this scheme has significant advantages in terms of encryption performance and security,and provides a reliable protection mechanism for fingerprint authentication systems in the Internet of things environment. 展开更多
关键词 four-dimensional superchaotic system fingerprint template protection Zernike moments image encryption
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Tamper Detection in Multimodal Biometric Templates Using Fragile Watermarking and Artificial Intelligence
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作者 Fatima Abu Siryeh Hussein Alrammahi Abdullahi Abdu İbrahim 《Computers, Materials & Continua》 2025年第9期5021-5046,共26页
Biometric template protection is essential for finger-based authentication systems,as template tampering and adversarial attacks threaten the security.This paper proposes a DCT-based fragile watermarking scheme incorp... Biometric template protection is essential for finger-based authentication systems,as template tampering and adversarial attacks threaten the security.This paper proposes a DCT-based fragile watermarking scheme incorporating AI-based tamper detection to improve the integrity and robustness of finger authentication.The system was tested against NIST SD4 and Anguli fingerprint datasets,wherein 10,000 watermarked fingerprints were employed for training.The designed approach recorded a tamper detection rate of 98.3%,performing 3–6%better than current DCT,SVD,and DWT-based watermarking approaches.The false positive rate(≤1.2%)and false negative rate(≤1.5%)were much lower compared to previous research,which maintained high reliability for template change detection.The system showed real-time performance,averaging 12–18 ms processing time per template,and is thus suitable for real-world biometric authentication scenarios.Quality analysis of fingerprints indicated that NFIQ scores were enhanced from 2.07 to 1.81,reflecting improved minutiae clarity and ridge structure preservation.The approach also exhibited strong resistance to compression and noise distortions,with the improvements in PSNR being 2 dB(JPEG compression Q=80)and the SSIM values rising by 3%–5%under noise attacks.Comparative assessment demonstrated that training with NIST SD4 data greatly improved the ridge continuity and quality of fingerprints,resulting in better match scores(260–295)when tested against Bozorth3.Smaller batch sizes(batch=2)also resulted in improved ridge clarity,whereas larger batch sizes(batch=8)resulted in distortions.The DCNN-based tamper detection model supported real-time classification,which greatly minimized template exposure to adversarial attacks and synthetic fingerprint forgeries.Results demonstrate that fragile watermarking with AI indeed greatly enhances fingerprint security,providing privacy-preserving biometric authentication with high robustness,accuracy,and computational efficiency. 展开更多
关键词 Biometric template security fragile watermarking deep learning tamper detection discrete cosine transform(DCT) fingerprint authentication NFIQ score optimization AI-driven watermarking structural similarity index(SSIM)
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Two-dimensional micrometer-sized CuFeSeS nanosheets:template-mediated chemical synthesis and magnetic regulation
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作者 Wen-Jiao Liu Yu-Jia Li +5 位作者 Rui-Fang Ding Hui Zhang Yan-Qing Hao Yang Liu Lan-Fang Wang Xiao-Hong Xu 《Rare Metals》 2025年第7期4815-4825,共11页
The fundamental research and potential applications of magnetic two-dimensional(2D)ternary chalcogenides in spintronics have garnered considerable interest.Lessening the thickness of non-van der Waals(nvdWs)ternary ch... The fundamental research and potential applications of magnetic two-dimensional(2D)ternary chalcogenides in spintronics have garnered considerable interest.Lessening the thickness of non-van der Waals(nvdWs)ternary chalcogenides to 2D structures can bring about novel physical phenomena and contribute to their potential applications m spintronics.In this paper,a template-mediated chemical synthesis was proposed to prepare nvdWs2D micrometer-sized CuFeSeS composite nanosheets.Specifically,free-standing 2D nvdWs hexagonal CuFeSeS with a mean size of 2.6μm was successfully achieved.The anisotropic growth of CuFeSeS was induced by the confinement effect of the template.Inspiringly,the 2D hexagonal CuFeSeS nanosheets with higher Fe content exhibit intrinsic ferromagnetic order,with a huge coercivity(HC)of 10.99 kOe at 5 K.The magnetism is regulated by varying the Fe content and reaction temperature.The valence changes of Fe,which form the ferromagnetic Fe7S8phase,play a crucial role in the magnetic transitions.This work enlightens the synthesis of 2D nvdWs ternary chalcogenides and promotes the potential applications of2D hexagonal CuFeSeS nanosheets in spintronics. 展开更多
关键词 2D ternary chalcogenide Micrometer-sized CuFeSeS nanosheets template mediated synthesis Magnetic regulation
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Preparation of Porous Alumina Ceramics by Sacrificial Template Method
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作者 ZHU Tianli WANG Kexiu +1 位作者 WANG Youfa ZHENG Bowen 《Journal of Wuhan University of Technology(Materials Science)》 2025年第5期1213-1222,共10页
Corn starch was used as a templating agent,and an oxide mixture containing alumina,magnesia,zirconia and yttria was added in the sol-gel state.After slip casting,curing at 85℃,drying and sintering,high-performance po... Corn starch was used as a templating agent,and an oxide mixture containing alumina,magnesia,zirconia and yttria was added in the sol-gel state.After slip casting,curing at 85℃,drying and sintering,high-performance porous alumina ceramics were obtained.The properties of the porous alumina ceramics were analyzed by means of SEM,XRD,flexural strength and porosity.The research findings showed that,when the starch content was 1 wt%,the prepared ceramic mainly consisted of four phases:α-Al_(2)O_(3),MgAl_(2)O_(4),ZrO,and YSZ.The flexural strength reached 157.27 MPa,the flexural strength of the green body was about 3 MPa,and the porosity was around 30%. 展开更多
关键词 sacrificial template porous alumina ceramics flexural strength
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A Self-Sacrifice Template Method to Produce FeS Encapsulated into N,S Co-Doped Carbon for Improved Lithium Storage Performance
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作者 Xu Liu Lan-Yun Yang +7 位作者 Li-Ting Zeng Yun Peng Chen-Xi Xu Lei Li Jia-Le Sun Yang-Yang Chen Liang Chen Zhao-Hui Hou 《Acta Metallurgica Sinica(English Letters)》 2025年第9期1637-1644,共8页
The development of high-performance transition metal sulfide(TMS)/carbon composites to replace conventional graphite anode remains a critical challenge for advancing lithium-ion batteries(LIBs).In this study,a facile ... The development of high-performance transition metal sulfide(TMS)/carbon composites to replace conventional graphite anode remains a critical challenge for advancing lithium-ion batteries(LIBs).In this study,a facile self-sacrifice template method is developed to prepare FeS encapsulated into N,S co-doped carbon(FeS/NSC)composite using melamine-cyanuric acid(MCA)supermolecule as a multifunctional template precursor.The function of MCA supermolecule for material synthesis is explored,revealing its special function as a dispersant,dopant and pore-forming agent.Furthermore,the effect of Fe source dosage on the morphology,structure and composition of the final products is explored.The resultant FeS/NSC-0.1(where 0.1 represents the mass of added Fe source)exhibits the most optimal proportion,characterized by a good dispersion status of FeS within the NSC matrix,effective N,S co-doping and ample porosity.Benefiting from these merits,the FeS/NSC-0.1 anode demonstrates significantly improved cycling stability and rate capability when compared to the counterparts.Undoubtedly,this work offers a universal method to produce advanced transition metal sulfide/carbon composite electrodes for energy storage and conversion systems. 展开更多
关键词 Lithium-ion batteries Lithium storage performance Self-sacrifice template method Melamine-cyanuric acid(MCA)supermolecule FeS encapsulated into N S co-doped carbon(FeS/NSC)composite
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Fabrication and Characterization of LiFePO4 Nanotubes by a Sol-gel-AAO Template Process 被引量:4
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作者 刘晓红 王金清 +1 位作者 张俊彦 杨生荣 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 北大核心 2006年第6期530-534,共5页
The LiFePO4 nanotubes were successfully fabricated by a sol-gel method with porous anodic aluminum oxide as the template. Transmission electron microscopy and scanning electron microscopy showed that the synthesized L... The LiFePO4 nanotubes were successfully fabricated by a sol-gel method with porous anodic aluminum oxide as the template. Transmission electron microscopy and scanning electron microscopy showed that the synthesized LiFeP04 nanotubes were monodispersed and parallel to one another. Selected area electron diffraction pattern, X-ray diffraction and X-ray photoelectron spectroscopy investigations jointly demonstrated that the synthesized LiFePO4 nanotubes were pure olivine structure. This approach offered a potentially way for fabricating ordered LiFePO4 nanotubes at room temperature and ambient conditions, which might be expected to find promising application as a new cathode material in lithium ion battery, 展开更多
关键词 LIFEPO4 AAO template SOL-GEL Lithium ion battery
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Facile template-induced synthesis of Ag-modified TiO_2 hollow octahedra with high photocatalytic activity 被引量:2
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作者 王雪飞 余锐 +2 位作者 王康 杨桂全 余火根 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2015年第12期2211-2218,共8页
Noble metal/titania hollow nanomaterials usually exhibit excellent photocatalytic activity because of their high specific surface area,low density,good surface permeability,strong light-harvesting capacity,and rapid i... Noble metal/titania hollow nanomaterials usually exhibit excellent photocatalytic activity because of their high specific surface area,low density,good surface permeability,strong light-harvesting capacity,and rapid interfacial charge transfer. However,the present preparation methods usually include complicated and multistep procedures,which can cause damage to the hollow nanostructures. In this paper,a facile template-induced synthesis,based on a template-directed deposition and in situ template-sacrificial dissolution,was employed to prepare Ag-modified TiO 2(Ag/TiO 2) hollow octahedra using Ag2 O octahedra as templates and TiF 4 as the precursor. In the synthetic strategy,the shells of TiO 2 hollow octahedra were formed by coating TiO 2 nanoparticles on the surface of Ag2 O templates based on the template-directed deposition. Simultaneously,the Ag2 O templates can be in situ removed by dissolving the Ag2 O octahedral template in HF solution produced via the hydrolysis reaction of TiF 4 in the reaction system. In addition,Ag nanoparticles were deposited on the inside and outside surfaces of TiO 2 shells by effectively using the photosensitive properties of Ag2 O and Ag+ ions under light irradiation,along with the formation of TiO 2 hollow octahedra. The Ag/TiO 2 hollow octahedra exhibited high photocatalytic activity because of their(1) short diffusion distances between photogenerated electrons and holes because of the thin shells of Ag/TiO 2 hollow octahedral,(2) deposition of Ag nanoparticles on the inside and outside surfaces of TiO 2 shells,and(3) rapid interfacial charge transfer between TiO 2 shells and Ag nanoparticles. This work may also provide new insights into preparing other Ag-modified and hollow nanostructured photocatalysts. 展开更多
关键词 Photocatalysis Silver Titanium dioxide Hollow octahedral Interfacial charge transfer template
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Growth behavior of CVD diamond in microchannels of Cu template 被引量:3
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作者 刘学璋 张雄伟 余志明 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第6期2009-2017,共9页
Deposition of diamond inside the trenches or microchannels by chemical vapor deposition (CVD) is limited by the diffusion efficiency of important radical species for diamond growth (H, CH3) and the pore depth of t... Deposition of diamond inside the trenches or microchannels by chemical vapor deposition (CVD) is limited by the diffusion efficiency of important radical species for diamond growth (H, CH3) and the pore depth of the substrate template. By ultrasonic seeding with nanodiamond suspension, three-dimensional (3D) penetration structure diamond was successfully deposited in cylindrical microchannels of Cu template by hot-filament chemical vapor deposition. Micro-Raman spectroscopy and scanning electron microscopy (SEM) were used to characterize diamond film and the effects of microchannel depth on the morphology, grain size and growth rate of diamond film were comprehensively investigated. The results show that diamond quality and growth rate sharply decrease with the increase of the depth of cylindrical microchannel. Individual diamond grain develops gradually from faceted crystals into micrometer cluster, and finally to ballas-type nanocrystalline one. In order to modify the rapid decrease of diamond quality and growth rate, a new hot filament apparatus with a forced gas flow through Cu microchannels was designed. Furthermore, the growth of diamond film by new apparatus was compared with that without a forced gas flow, and the enhancement mechanism was discussed. 展开更多
关键词 chemical vapor deposition DIAMOND template Cu substrate MICROCHANNEL
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Template synthesis of MnO_2/CNT nanocomposite and its application in rechargeable lithium batteries 被引量:4
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作者 邹敏敏 艾邓均 刘开宇 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第9期2010-2014,共5页
Nanostructured MnO2/CNT composite was synthesized by a soft template approach in the presence of Pluronic P123 surfactant. The product was characterized by X-ray diffraction, thermogravimetric and differential thermal... Nanostructured MnO2/CNT composite was synthesized by a soft template approach in the presence of Pluronic P123 surfactant. The product was characterized by X-ray diffraction, thermogravimetric and differential thermal analyses, Fourier transformed infrared spectroscopy and high-resolution transmission electron microscopy. The results show that the sample consists of poor crystalline α-MnO2 nanorods with a diameter of about 10 nm and a length of 30-50 nm, which absorb on the carbon nanotubes. The electrochemical properties of the product as cathode material for Li-MnO2 cell are evaluated by galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS). Compared with pure MnO2 electrode, the MnO2/CNT composite delivers a much larger initial capacity of 275.3 mA-h/g and better rate and cycling performance. 展开更多
关键词 MnO2/CNT soft template NANOCOMPOSITE rechargeable lithium batteries
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Preparation and improved photocatalytic activity of ordered mesoporous TiO_2 by evaporation induced self-assembly technique using liquid crystal as template 被引量:2
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作者 刘晨 李佑稷 +2 位作者 徐鹏 李泽时 曾孟雄 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第4期1072-1078,共7页
Ordered mesoporous TiO2 (OMPT) was prepared by an evaporation induced self-assembly technique using liquid crystal as template. The key factors affecting the methylene blue (MB) oxidation efficiency were investiga... Ordered mesoporous TiO2 (OMPT) was prepared by an evaporation induced self-assembly technique using liquid crystal as template. The key factors affecting the methylene blue (MB) oxidation efficiency were investigated, including the initial concentration of MB, pH value and catalyst concentration. The results show that the obtained OMPT has high thermal stability and shows a 2D hexagonal mesostructure with the small particle size and high surface area, which lead to higher degradation efficiency than commercial P25 or nanoparticle TiO2 (NPT) fabricated by sol-gel process. The optimal conditions are 5 mg/L MB, pH 6 and 1.5 g/L OMPT for the fastest rate of MB degradation. Total organic carbon (TOC) analysis indicates complete mineralization of MB in 240 min by OMPT, with rate constant higher than NPT or P25. 展开更多
关键词 TITANIA ordered mesopore liquid crystal template methylene blue degradation
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Synthesis of Biomorphic ZrO2-CeO2 Nanostructures by Silkworm Silk Template 被引量:1
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作者 张宗见 李嘉 +2 位作者 孙富升 吴恒亮 邝丰栾 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2010年第3期351-354,I0002,共5页
A simple and green technique has been developed to prepare hierarchical biomorphic ZrO2- CeO2, using silkworm silk as the template. Different from traditional immersion technics, the whole synthesis process depends mo... A simple and green technique has been developed to prepare hierarchical biomorphic ZrO2- CeO2, using silkworm silk as the template. Different from traditional immersion technics, the whole synthesis process depends more on the restriction or direction functions of the silkworm silk template. The analytic results showed that ZrO2-CeO2 exhibited a well-crystallized hierarchically interwoven hollow fiber structure with 16-28 μm in diameter. The grain size of the sample calcined at 800 ℃ was about 14 nm. Consequently, the interwoven meshwork at three dimensions is formed due to the direction of biotemplate. The action mechanism is summarily discussed here. It may bring the biomorphic ZrO2-CeO2 nanomaterials with hierarchical interwoven structures to more applications, such as catalysts. 展开更多
关键词 NANOMATERIAL CATALYST ZrO2-CeO2 Biomorphic Silkworm silk template
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