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The h_∞ synchronization of nonlinear Bloch systems via dynamic feedback control approach

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Chinese Physics B 2011年第7期20卷 101-106页

作者： D.h. ji J.h. Koo S.C. Won Ju h. Park Mobile Communication Division Digital Media and Communications Samsung Electronics Co. Ltd 416-2 Maetan-Dong Suwon 443-803 Republic of Korea Department of Electronic and Electrical Engineering Pohang University of Science and Technology San 31 Hyoja-Dong Pohang 790-784 Republic of Korea Department of Electrical Engineering Yeungnam University 214-1 Dae-Dong Kyongsan 712-749 Republic of Korea

We consider an h∞ synchronization problem in nonlinear Bloch systems. Based on Lyapunov stability theory and linear matrix inequality formulation, a dynamic feedback controller is designed to guarantee asymptotic stability of the master-slave synchronization. Moreover, this controller reduces the effect of an external disturbance to the h∞ norm constraint. A numerical example is given to validate the proposed synchronization scheme.

关键词： h∞ synchronization Bloch system dynamic control linear matrix inequality

A hybrid Signal Processing Method Combining Mathematical Morphology and Walsh Theory for Power Quality Disturbance Detection and Classification

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 584-592页

作者： Zhi Ding Tianyao ji Mengshi Li Q.h.Wu School of Electric Power Engineering South China University of Technology(SCUT)Guangzhou 510641China

In this paper, a novel signal processing method combining mathematical morphology (MM) and Walsh theory is proposed, which uses Walsh functions to control the structuring element (SE) and MM operators. Based on the Walsh-MM method, a scheme for power quality disturbances detection and classification is developed, which involves three steps: denoising, feature extraction and morphological clustering. First, various evolution rules of Walsh function are used to generate groups of SEs for the multiscale Walsh-ordered morphological operation, so the original signal can be denoised. Next, the fundamental wave of the denoised signal is suppressed by hadamard matrix;thus, disturbances can be extracted. Finally, the Walsh power spectrum of the waveform extracted in the previous step is calculated, and the parameters of which are taken by morphological clustering to classify the disturbances. Simulation results reveal the proposed scheme can effectively detect and classify disturbances, and the Walsh-MM method is less affected by noise and only involves simple calculation, which has a potential to be implemented in hardware and more suitable for real-time application.

关键词： hadamard matrix mathematical morphology morphological clustering power quality disturbance Walsh theory

PLASMA SPRAYED Ti AND hA COATINGS: A COMPARATIVE STUDY BETWEEN APS AND VPS

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Acta Metallurgica Sinica(English Letters) 2005年第3期18卷 339-344页

作者： X.B.Zheng h.ji J.Q.huang C.X.Ding ShanghaiInstituteofCeramics TheChineseAcademyofSciencesShanghai200050China

Titanium (Ti) and hydroxyapatite (hA) coatings have been prepared via air (APS) and vacuum plasma spraying (VPS), and then their composition, structure, bonding strength and bioactivity were examined. The results obtained reveal that in APS process many of Ti were oxidized, but in VPS the oxidization was avoided. VPS T i coating possesses better bonding condition than APS Ti coating. As for hA coat ing, higher crystallinity has been obtained while the coating was deposited by V PS as compared with APS. The simulated body fluid (SBF) tests show that both of APS and VPS hA coatings possess good bioactivity. As compared with APS, VPS is r ecommended as a better method to deposit Ti and hA coatings that can be applied as hard tissue replacement implants.

关键词： vacuum plasma spray Ti hA biocoating

ThE SYNThESIS AND 2D NMR STUDY OF DELTORPhINS

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Chinese Chemical Letters 1995年第4期6卷 285-288页

作者： Wang, R hu, XY ji, h Xu, XJ Zhang, Rh Lai, Lh Lanzhou Univ Dept Biol Natl Lab Appl Organ Chem Lanzhou 730000 Peoples R China Beijing Univ Dept Chem Beijing 100831 Peoples R China

We synthesized Deltorphin I, Deltorphin II, and their L-Alanine analogs at position 2. The synthesis was carried out with SPPS and Boc strategy. The data, we got from FAB MS, AAA and sequence analysis were in agreement with the calculated values. We studied the 2D NMR for Deltorphin II and [L-Ala(2)]Deltorphin II in DMSO solution. The h-1-h-1 COSY and 2D NOESY spectra were resolved by computer treatment. The conformations of C-fragment tetrapeptides of Deltorphin II and its L-Ala analog might form a 3(10) alpha -helix. The molecular models of these two peptides were established.

关键词： NMR ThE SYNThESIS AND 2D NMR STUDY OF DELTORPhINS

COMPARISON OF SURFACE PROPERTIES OF Ti-6Al-4V COATED WITh TITANIUM NITRIDE, TiN+TiC+Ti(C,N)/DLC, TiN/DLC AND TiC/DLC FILMS BY PLASMA-BASED ION IMPLANTATION

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Acta Metallurgica Sinica(English Letters) 2000年第4期13卷 967-973页

作者： ji, h.B. Xia, L.F. Ma, X.X. Sun, Y. Sun, M.R. harbin Inst of Technology Harbin China

The surface properties of Ti-6Al-4V alloy coated with titanium nitride, TiN+TiC+Ti(C,N)/DLC (diamond like carbon), TiN/DLC and TiC/DLC films by plasma-based ion implantation (PBII) with nitrogen, PBII with nitrogen then acetylene, PBII with nitrogen then glow discharge deposition with acetylene plus hydrogen and PBII with acetylene then glow discharge deposition with acetylene plus hydrogen respectively were studied. The corresponding films are found getting dimmer, showing light gold or gold, smoky color (uneven), light red in black (uneven), and graphite black separately. The corresponding film resistivities are given. Antioxidation ability of the titanium nitride film is poor, while the existence of carbon (or carbide) improves the antioxidation ability of the films. having undergone excellent intermediate transitional region of nitrogen and carbon implantation, the top DLC layer of the TiN+TiC+Ti(C,N)/DLC multilayer are formed after the carbon implantation has the best adhesion with the substrate among all the multilayers. Although microhardness of the samples increases in the order of coatings of titanium nitride, TiN/DLC, TiN+TiC+Ti(C,N)/DLC and TiC/DLC, the TiN/DLC and TiC/DLC multilayers have greater brittleness as compared with other films.

关键词： Titanium alloys Titanium nitride Plasmas Ion implantation Microhardness Surface properties

Dispersion and Damage of Carbon Nanotubes in Carbon Nanotube/7055Al Composites During high-Energy Ball Milling Process

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Acta Metallurgica Sinica(English Letters) 2021年第2期34卷 196-204页

作者： S.Bi B.L.Xiao Z.h.ji B.S.Liu Z.Y.Liu Z.Y.Ma Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang 110016China School of Material Science and Engineering University of Science and Technology of China72 Wenhua RoadShenyang 110016China AVIC Manufacturing Technology Institute Beijing 100024China

high-energy ball milling(hEBM)combined with powder metallurgy route was used to fabricate carbon nanotube(CNT)reinforced 7055 Al *** powder morphology evolution processes(hEBM-1 and hEBM-2)were designed to investigate the dispersion and damage of CNTs during hEBM ***-1 evolution process involved powder fl attening,cold-welding and fracture,while hEBM-2 evolution process consisted of powder fl attening and *** hEBM-1,the repetitive fracture and cold-welding process was effective for dispersing ***,the powder fl attening process in hEBM-2 was unsuccessful in dispersing CNTs due to two reasons:(1)the thickness of fl aky Al powders exceeded the critical value,and(2)the clustered CNTs embedded in fl aky Al powders could not be *** of the broadening of D band and the appearance of a new defect-related D’band,product of I D/I G and full width half maximum of D band,rather than I D/I G,was used to evaluate the actual damage of *** indicates that the damage of CNTs was severe in powder fl attening and fracture stages,while the damage of CNTs was small in powder cold-welding stage.

关键词： Metal matrix composites Carbon nanotubes Powder evolution Dispersion and damage Powder metallurgy

Boosting electrocatalytic nitrate reduction to ammonia via Cu_(2)O/Cu(Oh)_(2)heterostructures promoting electron transfer

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Nano Research 2024年第6期17卷 4898-4907页

作者： jing Geng Sihan ji Anhui Province International Research Center on Advanced Building Materials School of Materials Science and Chemical EngineeringAnhui Jianzhu UniversityHefei 230601China Anhui Province Key Laboratory of Advanced Building Materials Anhui Jianzhu UniversityHefei 230601China School of Energy Materials and Chemical Engineering Hefei UniversityHefei 230601China

Electrocatalytic nitrate(NO_(3)^(−))reduction to ammonia(Nh_(3))offers a viable approach for sustainable Nh_(3)production and environmental ***(Cu)possesses a distinctive electronic structure,which can augment the reaction kinetics of NO_(3)^(−)and impede hydrogen evolution reaction(hER),rendering it a promising contender for the electrosynthesis of Nh_(3)from NO_(3)^(−).Nevertheless,the role of Cu_(2)O in copper-based catalysts still requires further investigation for a more comprehensive ***,the Cu_(2)O/Cu(Oh)_(2)heterostructures are successfully fabricated through liquid laser irradiation using CuO nanoparticles as a *** and theoretical researches reveal that Cu_(2)O/Cu(Oh)_(2)heterostructure exhibits enhanced electrocatalytic performance for NO_(3)^(−)to Nh_(3)because Cu(Oh)_(2)promotes electron transfer and reduces the valence state of Cu active site in Cu_(2)***−0.6 V(*** hydrogen electrode(RhE)),the Nh_(3)yield reaches its maximum at 1630.66±29.72μg·h^(−1)·mgcat^(−1),while the maximum of Faraday efficiency(FE)is 76.95%±5.51%.This study expands the technical scope of copper-based catalyst preparation and enhances the understanding of the electrocatalytic mechanism of NO_(3)^(−)to Nh_(3).

关键词： Cu_(2)O/Cu(Oh)_(2)heterostructures electron transfer ammonia synthesis electrocatalysts nitrate

Restricted Arc-Connectivity of harary Digraphs

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Journal of the Operations Research Society of China 2024年第2期12卷 540-547页

作者： Jun-hao Zhang ji-Xiang Meng College of Mathematics and System Science Xinjiang UniversityUrumqi 830046XinJiangChina

The h-restricted arc-connectivity of a digraph is an important parameter to measure fault-tolerance of interconnection *** paper determines that the h-restricted arc-connectivity of the harary digraph D=G(n;1,2,.:,k)is equal to n/2 for 2≤h≤n/2,k=2 and n iseven,andλ_(h)(D)=g(k-1)for 2h≤g and 3≤k≤n/2,where g is the girth of *** consequences,the super restricted arc-connectedness of harary digraph D is obtained *** particular,for k=2 and n is even or 3≤khat distinct positive(respectively,negative)Ah-superatoms of D are vertex disjoint for 2≤h≤g.

关键词： Restricted arc-connectivity λ_(h)(D) Super-λ_(h) λ_(h)-Atom λ_(h)-Superatom

Polyoxometalates for continuous power generation by atmospheric humidity

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Nano Research 2024年第3期17卷 1875-1885页

作者： Tuo ji Weilin Chen Zhenhui Kang Liming Zhang Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education Northeast Normal UniversityChangchun 130024China Institute of Functional Nano&Soft Materials(FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials&Devices DepartmentSoochow UniversitySuzhou 215123China Macao Institute of Materials Science and Engineering Macao University of Science and TechnologyTaipaMacao 999078China Institute of Functional State Key Laboratory of Luminescence and Applications Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China

Atmospheric humidity is a sustainable low-value energy widely existing in natural environment,which is a promising candidate to solve the noncontinuous and low efficiency of low-value energy power *** the mono-substituted Dawson-type polyoxometalates are constructed to be highly dispersed organic ammonium-polyoxoanion clusters and are assembled into thin films power generators with micropores,working in atmospheric *** optimal polyoxometalates generator with the thickness of 7.2μm and the area of 0.36 cm^(2) produces a voltage of 0.68 V and a current density of 19.5μA·cm^(-2) under simulated natural environment,and works continuously and stably under almost all-natural environments(humidity 10%–90%).The highly dispersed polyoxometalate nanoclusters can form microporous in polyoxometalate films to effectively absorb atmospheric humidity and spontaneously form distribution gradient of water,which is the structural basis of power *** continuous power generation may be maintained by the effective adsorption and utilization of h_(2)O,the huge electrostatic field of organic ammonium-polyoxoanion clusters,and the reasonably designed polyoxometalates containing inorganic small ions with high *** is the first humidity generator designed with polyoxometalates,which may provide a new research direction for polyoxometalates in sustainable utilization of low-value energy.

关键词： atmospheric humidity continuous power generations nanomaterials polyoxoanions polyoxometalates