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On d-row(Column) Antimagic Matrices and Subset Partitions

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Acta Mathematicae Applicatae Sinica 2021年第1期37卷 192-200页

作者： Zhi-he LIANG shi-xin LIANG School of Mathematical Science Hebei Normal UniversityShijiazhuang 050024China ABB Electric Transmission Systems Co.LTD Beijing 100020China

An m×k matrix is said to be a d-row(column)antimagic matrix if its row-sums(column-sums)form an arithmetic progression with a difference *** goal of this paper is to obtain the existence theorems and construction methods of some d-row(column)antimagic *** these results we give the necessary and sufficient condition for the existence of an(m,d)-partition of[1,mk].

关键词： matrix d-row(column)antimagic matrix subset partition

Effects of porous oxide layer on performance of Pd-based monolithic catalysts for 2-ethylanthraquinone hydrogenation

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Chinese Journal of Chemical Engineering 2016年第11期24卷 1570-1576页

作者： xin shi Enxian Yuan Guozhu Liu Li Wang Key Laboratory for Green Chemical Technology of the Ministry of Education School of Chemical Engineering and Technology Tianjin University Tianjin 300072 China Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin 300072 China

Pd/oxide/cordierite monolithic catalysts(oxide = Al_2O_3, SiO_2 and SiO_2\\Al_2O_3) were prepared by the impregnation method. The results of ICP, XRD, SEM–EDX, XPS and N_2 adsorption–desorption measurements revealed that the Pd penetration depth increased with increasing the thickness of oxide layer, and the catalysts with Al_2O_3 layers had the larger pore size than those with SiO_2 and SiO_2\\Al_2O_3 layers. Catalytic hydrogenation of 2-ethylanthraquinone(eA Q), a key step of the H_2O_2 production by the anthraquinone process, over the various monolithic catalysts(60 °C, atmosphere pressure) showed that the monolithic catalyst with the moderate thickness of Al_2O_3 layer(about 6 μm) exhibited the highest conversion of e AQ(99.1%) and hydrogenation efficiency(10.0 g·L^(-1)). This could be ascribed to the suitable Pd penetration depth and the larger pore size, which provides a balance between the distribution of Pd and accessibility of active sites by the reactants.

关键词： Monolith Catalyst Hydrogenation Anthraquinone Hydrogen peroxide Pd

Computing the k-error joint linear complexity of binary periodic multisequences

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The Journal of China Universities of Posts and Telecommunications 2013年第6期20卷 96-101页

作者： LI Fu-lin ZHU shi-xin School of Mathematics Hefei University of Technology

Complexity measures for multisequences over finite fields, such as the joint linear complexity and the k-error joint linear complexity, play an important role in cryptology. In this paper we study a fast algorithm, presented by Venkateswarlu A, to computer the k-error joint linear complexity of a binary periodic multisequence. In this paper, the aim is mainly to complement the theoretical derivation and proof of the existing algorithm. Moreover, our algorithm reduces computation.

关键词： cryptology multisequence algorithm joint linear complexity k-error joint linear complexity

Effects of fibrous fillers on friction and wear properties of polytetrafluoroethylene composites under dry or wet conditions

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China Particuology 2007年第6期5卷 414-419页

作者： Huaiyuan Wang xin Feng Yijun shi Xiaohua Lu State Key Laboratory of Materials-oriented Chemical Engineering Nanjing University of Technology Nanjing 210009 China

The friction and wear behavior and mechanism as well as the mechanical properties of polytetrafluoroethylene （PTFE） composites filled with potassium titanate whiskers （PTW） and short carbon fibers （CF） under dry, wet and alkaline conditions were investigated. Experiments indicated that owing to appropriate cooling and boundary lubricating effects, the filled PTFE composites showed much lower frictional coefficient and better wear resistance under alkaline than dry and wet sliding conditions. The wear resistance of carbon-fiber-filled PTFE was much better than that of potassium titanate-whisker-filled PTFE composites in water. Results also showed that the transfer film on counterpart rings was significantly hindered by water and alkali. Hydrophilic-filler-reinforced PTFE composites yield higher wear rate when sliding under water.

关键词： PTFE composites Whiskers Carbon fibers Friction and wear properties Alkaline solution

Chinese product of constacyclic and cyclic codes over finite rings

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The Journal of China Universities of Posts and Telecommunications 2013年第3期20卷 109-113页

作者： TANG Yong-sheng ZHU shi-xin School of Mathematics Hefei University of Technology Department of Mathematics Hefei Normal University

In this paper, we study the Gray images of the Chinese product of constacyclic and cyclic codes over a finite ring. We first introduce the Chinese product of constacyclic and cyclic codes over the finite ring. We then define a Gray map between codes over the finite ring and a finite field. We prove that the Gray image of the Chinese product of constacyclic codes over the finite ring is a distance-invariant quasi-cyclic code over the finite field. We also prove that each code over the finite field, which is the Gray image of the Chinese product of cyclic codes over the finite ring, is permutation equivalent to a quasi-cyclic code.

关键词： Chinese remainder theorem constacyclic codes cyclic codes quasi-cyclic codes

Characterization of Type p Banach Spaces by the Weak Law of Large Numbers

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Wuhan University Journal of Natural Sciences 2002年第1期7卷 14-19页

作者： Gan shi-xin School of Mathematics and Statistics Wuhan UniversityWuhan 430072HubeiChina

For weighted sums of the form?j=1kn anj Xnj\sum{_{j=1}^{k_(n)}}a_({nj})X_({nj})where{a_(nj),1?j?k_(n)↑∞,n?1}is a real constant array and{X_(aj),1≤j≤k n,n≥1}is a rowwise independent,zero mean,random element array in a real separable Banach space of typep,we establishL r convergence theorem and a general weak law of large numbers respectively,conversely,we characterize Banach spaces of typep in terms of convergence inr-th mean and probability for such weighted sums.

关键词： Banach space of typep array of random elements weighted sums weak law of large numbers {a nj} uniform integrability L r convergence convergence in probability

Effect of Microstructure on Wear Behavior of Iron Aluminide Based Coatings

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材料热处理学报 2004年第05B期25卷 938-941页

作者： ZHUZi-xin LIUYan XUBin-shi ZHANGWei MAshi-ning NationalKeyLaboratoryforRemanufacturing TheAcademyofArmoredForcesEngineeringBeijingChina

An experimental study has been carried out to investigate the effect of microstructure on sliding wear behavior of Fe-Al coatings and Fe-Al/WC composite coatings produced by high velocity arc spraying (HVAS) and cored wires. After heat treatment at 300°C, 450°C, 550°C, 650°C and 800°C, the microstructure of the coatings will be changed. The changes of microstructure have obvious effects on the microhardness of the coatings, which may be the most important factor influencing the coatings sliding wear behavior. After heat treated at 450°C-650°C, increasing of the amounts of iron aluminides (including Fe3Al and FeAl ) and dispersion strengthening of Fe2\V2C and Fe6W6C will lead to a rise of microhardness of the coatings. Increasing the microhardness through heat treatment would improve the sliding wear resistance of the iron aluminide based coatings coatings.

关键词：显微结构铁铝合金磨损性能高速电弧喷镀

One-pot Hydrothermal Synthesis of Novel NiCoO2/Reduced Graphene Oxide Composites for Supercapacitors

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Chemical Research in Chinese Universities 2017年第4期33卷 638-642页

作者： WANG Hongzhi shi xin shi Yulei ZHANG Weiguo YAO Suwei Department of Applied Chemistry School of Chemical Engineering and Technology Tianjin University Tianjin 300350 P. R. China

Novel NiCoO2/rGO composites with a structure of NiCoO2 nanoparticles anchored on layers of reduced graphene oxide（rGO） were synthesized via a simple one-pot hydrothermal method and were used as faradaic electrodes for supercapacitors. The microstructures of NiCoO2/rGO composites were characterized by means of field emission scanning electron microscopy（FESEM）, transmission electron microscopy（YEM）, X-ray diffraction（XRD） and thermogravimetric analysis（TGA）. When acting as faradaic electrodes for supercapacitors, NiCoO2/rCK） compo- sites exhibited a specific capacity of 288 C/g at the current density of 2 A/g and maintained 139.98 C/g at 20 A/g. High capacity retention ratios up to 88% could be achieved after 1000 cycles at a current density of 2 A/g. The out- standing cycling stability was primarily attributed to the combination of mixed transition metal oxides and rGO, which not only maintains a high electrical conductivity for the overall electrode but also prevents the aggregation and volume expansion of electrochemical materials during the cycling processes.

关键词： NiCoO2 rGO Composite Faradaic electrode Supercapacitor

Fast cooperative trajectory optimization and test verification for close-range satellite formation using Finite Fourier Series method

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Chinese Journal of Aeronautics 2020年第8期33卷 2224-2229页

作者： Mingying HUO Zichen FAN Naiming QI Zhiguo SONG xin shi School of Astronautics Harbin Institute of TechnologyHarbin 150001China China Academy of Launch Vehicle Technology Beijing 100076China

The process of formation reconfiguration for close-range satellite formation should take into account the risk of collisions between *** this end,this paper presents a method to rapidly generate low-thrust collision-avoidance trajectories in the formation reconfiguration using Finite Fourier Series(FFS).The FFS method can rapidly generate the collision-avoidance threedimensional *** results obtained by the FFS method are used as an initial guess in the Gauss Pseudospectral Method(GPM)solver to verify the applicability of the *** with the GPM method,the FFS method needs very little computing time to obtain the results with very little difference in performance *** verify the effectiveness,the proposed method is tested and validated by a formation control *** satellite simulators in the testbed are used to simulate two-dimensional satellite formation *** simulation and experimental results show that the FFS method can rapidly generate trajectories and effectively reduce the risk of collision between *** fast trajectory generation method has great significance for on-line,constantly satellite formation reconfiguration.

关键词： Collision-avoidance Finite Fourier Series(FFS) Satellite formation reconfiguration Satellite simulators Shape-Based(SB)method