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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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Preparation of Manganese Oxide Hollow Spheres Using pH-responsive Microgels as Templates
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作者 张伟 张志成 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2009年第3期327-332,340,共7页
Manganese oxide hollow spheres were prepared by a novel and facile approach using pH- responsive microgels as templates. The final products were thoroughly characterized with X-ray powder diffraction, thermogravimetri... Manganese oxide hollow spheres were prepared by a novel and facile approach using pH- responsive microgels as templates. The final products were thoroughly characterized with X-ray powder diffraction, thermogravimetric analysis, scanning electron microscopy, Fourier transform infrared, and transmission electron microscopy. The results reveal that the shell thickness of manganese oxide hollow spheres increased with the dosage of KMnO4, which implies that a controllable and feasible strategy for manganese oxide hollow spheres prepa- ration has been established. Further studies on the microgels template showed some of them had an irreversible swelling/deswelling transition due to the uneven cross-link extent. Based on the results, a probable formation mechanism for the hollow spheres was proposed. 展开更多
关键词 pH-responsive microgel templates based strategy Manganese oxide hollowsphere
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Personalized image-based templates for precise acetabular prosthesis placement in total hip arthroplasty:a pilot study 被引量:3
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作者 Bin CHEN Sheng-xiang XIAO Peng-cheng GU Xiang-jin LIN 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2010年第9期673-680,共8页
Objective:In order to achieve accurate implantation of the acetabular prosthesis in total hip arthroplasty(THA),we designed individual templates based on a three-dimensional(3D) model generated from computed tomo... Objective:In order to achieve accurate implantation of the acetabular prosthesis in total hip arthroplasty(THA),we designed individual templates based on a three-dimensional(3D) model generated from computed tomography(CT) scans.Methods:Individual templates were designed for 12 patients who underwent THA.A physical template was designed to conform to the contours of the patient's acetabulum and to confirm the rotation of the acetabular center.This guided the acetabular component orientation.Results:The preoperative and postoperative X-ray and CT scans were obtained to assess the location with respect to the accuracy of the acetabular component.For all patients,the abduction angle of the acetabular component was 46.7°to 54.3°and the anteversion angle was 11.3°to 18.5°Conclusions:The assessment of postoperative CT scans demonstrated higher accuracy of the acetabular component bore when used with the individual template.Therefore,the individual template can be an alternative to the computer-assisted navigation systems,with a good cost-performance ratio. 展开更多
关键词 Total hip arthroplasty templates Acetabular prosthesis
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A color based face detection system using multiple templates 被引量:1
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作者 王涛 卜佳酸 陈纯 《Journal of Zhejiang University Science》 CSCD 2003年第2期162-165,共4页
A color based system using multiple templates was developed and implem ented for detecting human faces in color images. The algorithm consists of three image processing steps. The first step is human skin color stati... A color based system using multiple templates was developed and implem ented for detecting human faces in color images. The algorithm consists of three image processing steps. The first step is human skin color statistics. Then it separates skin regions from non-skin regions. After that, it locates the fronta l human face(s) within the skin regions. In the first step, 250 skin samples from persons of different ethnicities are used to determine the color distribution o f human skin in chromatic color space in order to get a chroma chart showing lik elihoods of skin colors. This chroma chart is used to generate, from the origina l color image, a gray scale image whose gray value at a pixel shows its likelih ood of representing the skin. The algorithm uses an adaptive thresholding proces s to achieve the optimal threshold value for dividing the gray scale image into separate skin regions from non skin regions. Finally, multiple face templates ma tching is used to determine if a given skin region represents a frontal human fa ce or not. Test of the system with more than 400 color images showed that the re sulting detection rate was 83%, which is better than most color-based face dete c tion systems. The average speed for face detection is 0.8 second/image (400×300 pixels) on a Pentium 3 (800MHz) PC. 展开更多
关键词 Color-based Multiple templates matching Face detecti on
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Composition Templates in English Writing of the College Entrance Examination
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作者 史秀娟 《海外英语》 2014年第9X期115-116,132,共3页
In recent years,more and more students relay on universal composition templates.Students believe that the"universal composition template"can cope with all kinds of English tests.How the pros and cons of writ... In recent years,more and more students relay on universal composition templates.Students believe that the"universal composition template"can cope with all kinds of English tests.How the pros and cons of writing methods seem to put things right once and for all?How’s enlightening significance to English teaching?In this paper,based on the two language acquisition theory and analyze the advantages and disadvantages of the composition template,some suggestion are given to the students to improve their English writing level. 展开更多
关键词 COMPOSITION templates ENGLISH WRITING ENGLISH Coll
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A comparative study of assembly and disassembly process of dimeric and monomeric cyanine dyes with DNA templates
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作者 Lijia Yu Qianfan Yang Yalin Tang 《Chinese Chemical Letters》 SCIE CAS CSCD 2019年第3期694-697,共4页
Cyanine dyes have attracted more and more interest due to their controllable assembly and disassembly process with biomolecular templates. The self-assembly of cyanine dye not only depend on the environment, but also ... Cyanine dyes have attracted more and more interest due to their controllable assembly and disassembly process with biomolecular templates. The self-assembly of cyanine dye not only depend on the environment, but also on their structures. Here, we report assembly and disassembly of two cyanine dyes,a dimeric cyaine dye(TC-P4) and its corresponding monomer(TC). In PBS, these dyes could form aggregates. The parallel c-myc G-quadruplex as a template causes the transformation of TC-P4 from Haggregates to dimer and monomer; while duplex and single-stranded DNAs could not. The interaction between these DNAs motifs and TC could all induce the appearance of monomer band. Parallel c-myc Gquadruplex could enhance the fluorescence intensity of TC-P4 and TC. The self-assembly and disassembly of TC and TC-P4 could be regulated and used as probes for G-quadruplex recognition from duplex and single-stranded DNAs in solution. 展开更多
关键词 Cyanine DYE SUPRAMOLECULAR ASSEMBLY DNA templates G-QUADRUPLEX c-myc
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Mass-Stiffness Templates for Cubic Structural Elements Dedicated to Professor Karl Stark Pister for his 95th birthday
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作者 Carlos A.Felippa 《Computer Modeling in Engineering & Sciences》 SCIE EI 2021年第12期1209-1241,共33页
1 This paper considers Lagrangian finite elements for structural dynamics constructed with cubic displacement shape functions.The method of templates is used to investigate the construction of accurate mass-stiffness ... 1 This paper considers Lagrangian finite elements for structural dynamics constructed with cubic displacement shape functions.The method of templates is used to investigate the construction of accurate mass-stiffness pairs.This method introduces free parameters that can be adjusted to customize elements according to accuracy and rank-sufficiency criteria.One-and two-dimensional Lagrangian cubic elements with only translational degrees of freedom(DOF)carry two additional nodes on each side,herein called side nodes or SN.Although usually placed at the third-points,the SN location may be adjusted within geometric limits.The adjustment effect is studied in detail using symbolic computations for a bar element.The best SN location is taken to be that producing accurate approximation to the lowest natural frequencies of the continuum model.Optimality is investigated through Fourier analysis of the propagation of plane waves over a regular infinite lattice of bar elements.Focus is placed on the acoustic branch of the frequency-vs.-wavenumber dispersion diagram.It is found that dispersion results using the fully integrated consistent mass matrix(CMM)are independent of the SN location whereas its lowfrequency accuracy order is O(κ8),whereκis the dimensionless wave number.For the diagonally lumped mass matrix(DLMM)constructed through the HRZ scheme,two optimal SN locations are identified,both away from third-points and of accuracy order O(κ8).That with the smallest error coefficient corresponds to the Lobatto 4-point integration rule.A special linear combination of CMM and DLMM with nodes at the Lobatto points yields an accuracy of O(κ10)without any increase in the computational effort over CMM.The effect of reduced integration(RI)on both mass and stiffness matrices is also studied.It is shown that singular mass matrices can be constructed with 2-and 3-point RI rules that display the same optimal accuracy of the exactly integrated case,at the cost of introducing spurious modes.The optimal SN location in two-dimensional,bicubic,isoparametric plane stress quadrilateral elements is briefly investigated by numerical experiments.The frequency accuracy of flexural modes is found to be fairly insensitive to that position,whereas for bar-like modes it agrees with the one-dimensional results. 展开更多
关键词 Structural dynamics Lagrangian elements finite elements cubic shape functions bar plane stress mass STIFFNESS vibration wave propagation Fourier analysis dispersion templates
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NEURAL REGENERATION RESEARCH TEMPLATES
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《Neural Regeneration Research》 SCIE CAS CSCD 2014年第12期1172-1172,共1页
Invited Reviews-Submit an outline for your manuscript before writing and submit the manuscript within 2 months after receiving permission from NRR editorial committee.
关键词 NRR WORD NEURAL REGENERATION RESEARCH templates
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Hierarchically porous carbon cages synthesized through in situ migration of templates
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作者 Qing Fang Wei Zhang +2 位作者 Xinghua Chen Yuanjian Zhang Ming Hu 《Chinese Chemical Letters》 SCIE CAS CSCD 2020年第1期303-306,共4页
In order to optimize mass transportation and exchange,nature creates hierarchically porous networks which are composed of multi-level branches.Although bottom-up templating methods have succeeded in fabrication of the... In order to optimize mass transportation and exchange,nature creates hierarchically porous networks which are composed of multi-level branches.Although bottom-up templating methods have succeeded in fabrication of these kinds of hierarchically porous networks,the templates have to be assembled/packed in advance,therefore,driving the fabrication process too complex.In this report,we presented that the hierarchically porous networks could be fabricated through migration of templates,which was similar to formation of rive rs.During thermal pyrolysis of Prussian blue cages,the in situly generated iron oxides nanoparticles diffused and aggrega ted together to grow larger,and eventually moved outside from the porous carbons.The moving routes of the iron oxides became hierarchical channels in the obtained carbon cages.By using the porous carbon cages as electrode for Na-ion battery,a pseudocapacitor-type ion storage was investigated. 展开更多
关键词 Hierarchical structures Hierarchically porous carbon Mobile templates Thermal pyrolysis Na-ion battery
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NEURAL REGENERATION RESEARCH TEMPLATES
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《Neural Regeneration Research》 SCIE CAS CSCD 2014年第11期1092-1092,共1页
INVITED ARTICLESInvited Reviews -Submit an outline for your manuscript before writing and submit the manuscript within 2 months after receiving permission from NRR editorial com- mittee.
关键词 NRR WORD NEURAL REGENERATION RESEARCH templates
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Dimensional effects of organic anion templates in modulating the assembly of water clusters in cucurbit[6]uril supramolecular systems
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作者 Bo Li Xu-Zhuo Sun 《Chinese Chemical Letters》 SCIE CAS CSCD 2016年第3期417-422,共6页
Two new supramolecular architectures {(HC2O4)2^2- [C6H(18)N2^2+ C(36)H(36)N(24)O(12)]} 12H2O(1) and{(C6H5SO3)22 [C6H(18)N22+ C(36)H(36)N(24)O(12)]} 12H2O(2) were synthesized and character... Two new supramolecular architectures {(HC2O4)2^2- [C6H(18)N2^2+ C(36)H(36)N(24)O(12)]} 12H2O(1) and{(C6H5SO3)22 [C6H(18)N22+ C(36)H(36)N(24)O(12)]} 12H2O(2) were synthesized and characterized by singlecrystal X-ray diffraction, thermogravimetric analysis and X-ray powder diffraction. Compound 1contains infinite two dimensional(2D) L18(8)14(8)8(4) type anion–water aggregates [(HC2O4)4(H2O)(22)]^4- and results in the construction of sandwich-like three dimensional(3D) networks. In compound 2, honeycomb-like three dimensional(3D) networks are fabricated by one dimensional(1D)"W"-like T5(0)A2 type anion–water clusters [(C6H5SO3)(H2O)6]^-. These results indicate that anionic groups play a crucial role in modulating the structures of water clusters with their spatial structure and binding sites. In these two structures, the majority of interactions are O...H and H...H interactions on the Hirshfeld surface, which means that hydrogen bonding and hydrophobic interactions are the dominate drive forces in forming these supramolecular systems. 展开更多
关键词 uril Supramolecular Water clusters Anion templates Pseudorotaxane
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3-8 Surface Plasmonic Spectroscopy Revealing the Oxidation Dynamics of Copper Nanowires Embedded in Polycarbonate Ion-track Templates
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作者 Duan Jinglai Liu Jie +2 位作者 Zhang Yongliang Trautmann Christina Lei Dangyuan 《IMP & HIRFL Annual Report》 2015年第1期99-101,共3页
Metallic nanowires have attracted enormous attention since they open up exciting applications in the fields of electronics, plasmonics, sensors, green energy, and many more. Due to the large surface-area-to-volume rat... Metallic nanowires have attracted enormous attention since they open up exciting applications in the fields of electronics, plasmonics, sensors, green energy, and many more. Due to the large surface-area-to-volume ratio, however, they show enhanced chemical activity compared to their bulk counterparts and therefore are more easily susceptible to oxidization. 展开更多
关键词 POLYCARBONATE Ion-track templates
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Synthesis and Solid Phase Extraction Performance Study of NNAL-specific Molecularly Imprinted Polymers Using Dummy Templates 被引量:2
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作者 张志丹 郑赛晶 +3 位作者 杨俊 王维妙 刘百战 朱晓兰 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2013年第3期361-368,I0004,共9页
Dummy molecularly imprinted polymers (DMIPs) for 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) were produced using three structural analogues as dummy template molecules. The chosen analogues were 4-(a... Dummy molecularly imprinted polymers (DMIPs) for 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) were produced using three structural analogues as dummy template molecules. The chosen analogues were 4-(acetymethylamino)-1-(3-pyridyl)-butanol, 4- (methylamino)-1-(3-pyridyl)-1-butanol, and 1-(3-pyridyl)-1,4,-butanediol. The molecular recognition characteristics of the produced polymers were evaluated by X-ray photoelec- tron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR). Interactions between NNAL and methacrylic acid should be cooperative hydrogen bonds while the ni- trogen atom of the pyridine ring and the oxygen atom of the nitroso group in NNAL are two of the hydrogen-bond acceptors. It was further demonstrated that DMIP synthesized by 4-(acetymethylamino)-1-(3-pyridyl)-butanol had the best binding performance by XPS and FT-IR. Then dummy molecularly imprinted solid phase extraction (DMISPE) was developed for the determination of the analyte using the hit polymer as the sorbing material. Under optimal conditions, the recovery of NNAL dissolved in standard solution reached 93%. And the investigated polymer exhibited much higher binding of NNAL when nicotine was acted as the competitive molecule. Also the proposed method was applied to the measurement of NNAL spiked in blank urine samples with recoveries ranging from 87.2% to 101.2%. 展开更多
关键词 Molecularly imprinted polymer Dummy template 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanol Solid phase extraction
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Preparation of Poly(3-hydroxybutyrate) Porous Films by Microemulsion Templates Method
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作者 CAI Zhi jiang,CHENG Guo xiangSchool of Materials Science and Engineering of Tianjin University,Tianjin 300072,China 《Chinese Journal of Biomedical Engineering(English Edition)》 2002年第4期166-170,共5页
Porous poly(3 hydroxybutyrate)(PHB) membranes were prepared by microemulsion templates. The influence of microemulsion templates on pore size and porosity of the PHB membranes were studied. Preliminary studies showed... Porous poly(3 hydroxybutyrate)(PHB) membranes were prepared by microemulsion templates. The influence of microemulsion templates on pore size and porosity of the PHB membranes were studied. Preliminary studies showed that the pore size made by microemulsion templates were smaller and were estimated in the range of 100~500 nanometer. In this research, the ultraviolet/visible light spectrometer was applied in the investigation of H 2O/Span85 Tween60/chloroform reserve microemulsion. Surfactant content(P) and water content(R) were optimized. Furthermore, the effects of variation of P and R on the pore size and porosity of PHB films were discussed. 展开更多
关键词 Poly(3 hydroxybutyrate) MICROEMULSION templates
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Japanese-Chinese Machine Translation of Japanese Determiners Based on Templates
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作者 Ling Wang Zhongjian Wang 《Modern Electronic Technology》 2022年第1期43-48,共6页
The machine translation of Japanese sentences with determiners,like“shi­ka...nai”,“tyoutto...dakedeha”,“tada...dake”and so on,are more special and regular on sentences structure.The research collects and cl... The machine translation of Japanese sentences with determiners,like“shi­ka...nai”,“tyoutto...dakedeha”,“tada...dake”and so on,are more special and regular on sentences structure.The research collects and classifies the Japanese sentences which contain the determiners.The classification is carried out by according to the characteristics of Japanese sentences and translation habit of Chinese sentences.Through further abstraction and sim­plification,translation templates are extracted by gathering grammar rules information,studying syntax and analysis the collocation mode of sentenc­es.Those determiners express confirmed meaning,and the corresponding translation Chinese sentences have the same characteristic.By analyzing the sentence characteristics with determiners and formalizing the sentences struc­ture,the translation templates are abstracted.By investigating the structure characteristic of original sentences with translation templates,the similarity algorithm was defined.The threshold value of the similarity calculation was obtained by preliminary experiments,and the experiments of Japanese-Chi­nese translation are carried out by a small corpus.The experimental results for several kinds of Japanese sentences with determiners show the translation accuracy rate is 68.6%,template coverage rate reach 83.3%.At last,through the analysis for the translation errors,following conclusion is drawn:the results of morphological analysis are erroneous,because the error of word segmentation the part of speech tagging also are erroneous,result in the grammar structure cannot match with templates;the original sentences are long and especially complex sentences;the templates are too complicated;the similarity calculation method needs to discuss further,and so on. 展开更多
关键词 Japanese determiners Similarity calculation Machine translation Translation templates
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Empirical study of transpedicular screw placement assisted by digital navigation templates in the thoracic spines
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作者 陈玉兵 《外科研究与新技术》 2011年第2期93-93,共1页
Objective To investigate the accuracy and feasibility of transpedicular screw placement assisted by the navigation templates in cadaveric thoracic spines.Methods Twenty thoracic cadavers specimens were randomly divide... Objective To investigate the accuracy and feasibility of transpedicular screw placement assisted by the navigation templates in cadaveric thoracic spines.Methods Twenty thoracic cadavers specimens were randomly divided into two 展开更多
关键词 Empirical study of transpedicular screw placement assisted by digital navigation templates in the thoracic spines
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Design for CNN Templates with Performance of Global Connectivity Detection 被引量:9
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作者 LIUJin-Zhu MINLe-Quan 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第1期151-156,共6页
The cellular neural/nonlinear network (CNN) is a powerful tool for image and video signal processing,robotic and biological visions. This paper discusses a general method for designing template of the global connectiv... The cellular neural/nonlinear network (CNN) is a powerful tool for image and video signal processing,robotic and biological visions. This paper discusses a general method for designing template of the global connectivitydetection (GCD) CNN, which provides parameter inequalities for determining parameter intervals for implementing thecorresponding functions. The GCD CNN has stronger ability and faster rate for determining global connectivity in binarypatterns than the GCD CNN proposed by Zarandy. An example for detecting the connectivity in complex patterns isgiven. 展开更多
关键词 cellular neural network global connectivity detection template parameters
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Enhanced ethanol oxidation over Pd nanoparticles supported porous graphene-doped MXene using polystyrene particles as sacrificial templates 被引量:4
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作者 Yi-Zhe Chen Ming Zhou +8 位作者 Yu-Fu Huang Yan-Yun Ma Luo-Yi Yan Xin-Wen Zhou Xin-Zhou Ma Xue-Ling Zhao Cheng Chen Juan Bai Dong-Hai Lin 《Rare Metals》 SCIE EI CAS CSCD 2022年第9期3170-3179,共10页
Fabrication of superior catalytic performance palladium-based catalysts with affordable cost is the key to develop direct ethanol fuel cell.Herein,Pd-decorated three-dimensional(3D)porous constructed from graphene oxi... Fabrication of superior catalytic performance palladium-based catalysts with affordable cost is the key to develop direct ethanol fuel cell.Herein,Pd-decorated three-dimensional(3D)porous constructed from graphene oxide(GO)and MXene combining with polystyrene(PS)particles as sacrificial templates(Pd/GO-MXene-PS)to elevate the catalytic performance for ethanol oxidation was proposed.The 3D porous interconnected structure of Pd/GO-MXene-PS was characterized by scanning electron microscope(SEM),transmission electron microscope(TEM)and Brunner−Emmet−Teller(BET).By optimizing the doping ratio of MXene to GO,the mass activity of Pd/GO_(5)-MXene_(5)-PS(2944.0 mA·mg^(−1))was 3.0 times higher than that of commercial Pd/C(950.4 mA·mg^(−1))toward ethanol oxidation in base solution.Meanwhile,the rotating disk electrode(RDE)results demonstrated that Pd/GO5-MXene5-PS had a faster kinetics of ethanol oxidation.The enhanced ethanol oxidation over Pd/GO5-MXene5-PS could attribute to the excellent 3D interconnected porous structure,large surface area,good conductivity and homogeneous Pd distribution.This work provided a new idea for creating 3D porous MXene composite materials in electrocatalysis. 展开更多
关键词 Pd nanoparticles Ethanol oxidation GRAPHENE MXene Polystyrene(PS)template Rotating disk electrode(RDE)
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Fabrication of Large-area 3-D Ordered Silvercoated Colloidal Crystals and Macroporous Silver Films Using Polystyrene Templates 被引量:3
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作者 Wen Zhu Yuanyuan Wu +2 位作者 Chengyin Wang Ming Zhang Guanxiu Dong 《Nano-Micro Letters》 SCIE EI CAS 2013年第3期182-190,共9页
The highly ordered silver-coated colloidal crystals arrays and macroporous silver films were derived through an electrostatics-induced adsorption effect using polystyrene(PS) as templates. Carboxyl-modified PS microsp... The highly ordered silver-coated colloidal crystals arrays and macroporous silver films were derived through an electrostatics-induced adsorption effect using polystyrene(PS) as templates. Carboxyl-modified PS microspheres were prepared by emulsifier-free emulsion polymerization using methacrylic acid(MAA) as the functional monomer. PS microspheres were self-assembled into close packing colloidal crystals of facecentered cubic arrays to the substrate with vertical deposition method. These colloidal crystals were modified using dopamine(DA) to form poly-dopamine(PDA) during its oxidative polymerization. Through electrostatic interaction, the silver nanoparticles were deposited and adsorbed onto the surfaces of colloidal crystals templates by exposing [Ag(NH_3)_2]^+solution to infrared irradiation. Removal of the polymeric template by etching with methylbenzene solvent resulted in 3D ordered macroporous silver films. The structural and properties of the ordered silver-coated arrays and macroporous silver films were characterized by field emission scanning electron microscopy(FE-SEM), X-ray diffraction(XRD), UV-vis spectroscopy and surface-enhanced Raman spectroscopy(SERS). The results indicate that the prepared silver-coated arrays and macroporous silver films possess the features of ordered multilayer arrangement, uniformity and repeatability as well as an ideal SERS effect. 展开更多
关键词 Polystyrene colloidal crystal TEMPLATE DOPAMINE Silver-coated array Ordered macroporous film
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Induced growth of Fe-N_x active sites using carbon templates 被引量:2
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作者 Shiming Zhang Heyou Zhang +3 位作者 Weimin Zhang Xianxia Yuan Shengli Chen Zi-Feng Ma 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第8期1427-1435,共9页
Highly active Fe-N_x sites that effectively improve the performance of non-precious metal electrocatalysts for oxygen reduction reactions(ORRs) are desirable. Herein, we propose a strategy for introducing a carbon t... Highly active Fe-N_x sites that effectively improve the performance of non-precious metal electrocatalysts for oxygen reduction reactions(ORRs) are desirable. Herein, we propose a strategy for introducing a carbon template into a melamine/Fe-salt mixture to inductively generate highly active Fe-N_x sites for ORR. Using 57 Fe M?sbauer spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction, we studied the structural composition of the Fe and N co-doped carbon catalysts.Interestingly, the results showed that this system not only converted inactive Fe and Fe-carbides into active Fe-N_4 and other Fe-nitrides, but also improved their intrinsic activities. 展开更多
关键词 Oxygen reductionreaction Non‐precious‐metalelectrocatalyst Fe‐NxInduced growth Carbon template
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