检索结果-南通市图书馆

Constant-round auction with insulated bidders

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Science China(Information Sciences) 2022年第4期65卷 264-266页

作者： Jie ma Bin QI kewei LV State Key Laboratory of Information Security Institute of Information EngineeringChinese Academy of Sciences Data Assurance and Communication Security Research Center Chinese Academy of Sciences School of Cyber Security University of Chinese Academy of Sciences

Dear editor,In recent years, online auction has gained widespread popularity as a primary characteristic of electronic commerce among masses. It has also become a primary topic of research interest. Cryptographic primitives such as secure multiparty computation(MPC) [1], zero-knowledge proof(ZKP) [2] and commitment scheme [3] are being effectively utilized for the proposal of various schemes. Therefore,

关键词： Auction Commitment Integer Comparison Protocol Constant-round Blockchain

Improved Algorithm for Solving Discrete Logarithm Problem by Expanding Factor

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China Communications 2020年第4期17卷 31-41页

作者： Bin Qi Jie ma kewei Lv State Key Laboratory of Information Security Institute of Information EngineeringChinese Academy of SciencesBeijing 100093China Data Assurance Communication Security Research Center Chinese Academy of SciencesBeijing 100093China School of Cyber Security University of Chinese Academy of SciencesBeijing 100093China

The discrete logarithm problem(DLP)is to find a solution n such that g^n=h in a finite cyclic group G=,where h∈G.The DLP is the security foundation of many cryptosystems,such as RSA.We propose a method to improve Pollard’s kangaroo algorithm,which is the classic algorithm for solving the DLP.In the proposed algorithm,the large integer multiplications are reduced by controlling whether to perform large integer multiplication.To control the process,the tools of expanding factor and jumping distance are introduced.The expanding factor is an indicator used to measure the probability of collision.Large integer multiplication is performed if the value of the expanding factor is greater than the given bound.The improved algorithm requires an average of(1.633+o(1))q(1/2)times of the large integer multiplications.In experiments,the average large integer multiplication times is approximately(1.5+o(1))q(1/2).

关键词： discrete logarithm algorithm pollard’s kangaroo algorithm jumping distance

Structural and electronic properties of atomic oxygen adsorption on Cu(111) surface:A first-principles investigation

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Science China(Physics,Mechanics & Astronomy) 2013年第3期56卷 573-580页

作者： ma LiangCai ZHANG JianMin XU kewei College of Physics and Information Technology Shaanxi Normal University School of Physics and Electrical Information Engineering Ningxia University State Key Laboratory for Mechanical Behavior of materials Xi'an Jiaotong University

By using the first-principles calculations,we have systematically investigated the adsorption of atomic oxygen on Cu(111) surface for a wide range of coverages Θ(from 0.11 to 1.00 ML) and adsorption sites.We found that the fcc-hollow site is the most stable site for oxygen adsorption.The adsorption energy decreases with increasing oxygen coverage due to the increasing repulsive interaction in the overlayer O adatoms.Except for coverage of 1.00 ML,the oxygen-induced lateral relaxations and bucklings are found in the outermost three Cu layers,and the hillock-like as well as ridge-like bucklings are also found for Θ=0.25 ML and Θ=0.75 ML as well as Θ=0.50 ML,respectively.With an increasing oxygen coverage,the work function increases and the surface dipole moment decreases.Electron transfer from the first layer Cu atoms to O adatoms indicates the O-Cu bond having some degree of ionic character,while the hybridization between O 2p and Cu 3d orbitals implies that it also has some degree of covalence character.Moreover,with the increasing oxygen coverage,more Cu 3d and O 2p states are empty thus weakening the binding of O/Cu(111) system,but increase in the PDOS at the Fermi level.This implies an enhancement in the metallic character of the O/Cu(111) system.

关键词： adsorption oxygen relaxation electronic structures first-principles calculation

Robust Semi-nonnegative matrix Factorization with Adaptive Graph Regularization for Gene Representation

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Chinese Journal of Electronics 2020年第1期29卷 122-131页

作者： JIANG Wei ma Tingting FENG Xiaoting ZHAI Yun TANG kewei ZHANG Jie School of mathematics Liaoning Normal University E-Government Research Center Chinese Academy of Governance

Various data representation algorithms have been proposed for gene expression. There are some shortcomings in traditional gene expression methods,such as learning the ideal affinity matrix to effectively capture the geometric structure of genetic data space,and reducing noises and outliers influences of data input.We propose a novel matrix factorization algorithm called Robust semi-nonnegative matrix factorization(RSNMF)with adaptive graph regularization, which simultaneously performs matrix robust factorization with learning affinity matrix in a unified optimization framework. RSNMF also uses a loss function based on ?2,1-norm to improve the robustness of the model against noises and outliers.A novel Augmented Lagrange multiplier(ALM) is designed to obtain the optimal solution of RSNMF. The results of extensive experiments that were performed on gene expression datasets demonstrate that RSNMF outperforms the other algorithms, which validates the effectiveness and robustness of RSNMF.

关键词： Adaptive graph matrix factorization Robustness

First-principles study of the adsorption of oxygen atoms on copper nanowires

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Science China(Physics,Mechanics & Astronomy) 2012年第3期55卷 413-418页

作者： ma LiangCai ZHANG JianMin XU kewei College of Physics and Information Technology Shaanxi Normal UniversityXi’an 710062China School of Physics and Electrical Information Engineering Ningxia UniversityYinchuan 750021China Department of Physics Xi’an University of Arts and ScienceXi’an 710065China

By using first-principles calculations,we have systematically investigated the structural stability and electronic properties of a single oxygen atom adsorbed on the surface of foursquare Cu nanowires for a wide range of adsorption sites.In view of binding energy maximization,we found that the long bridge site at the edge of the Cu nanowires is the most stable site for oxygen adsorption,which is always slightly energetically favorable compared with the hollow site at the surface.The electron transferring from Cu atoms to O adatom and a significant polarization indicate the O-Cu chemical bond,showing some degree of ionic character.In addition,the hybridization between O-2p and Cu-3d states implies the O-Cu bond which also shows some degree of covalence character.The main factors which affect the oxygen preferred adsorption site are analyzed from the local geometrical configurations and electronic properties.

关键词：第一原理计算原子吸附铜原子纳米线氧原子结构稳定性电子性质吸附原子

Salt effect on MUCT system performance of nitrogen and phosphorus removal

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Green Energy & Environment 2021年第5期6卷 670-677页

作者： Huining Zhang Zhuowei Zhang kewei Jiang Zhili Li Kefeng Zhang Jianqing ma Yongxing Qian NingboTech University Ningbo315100China College of Water Sciences Beijing Normal UniversityBeijing100875China Ningbo Research Institute Zhejiang UniversityNingbo315100China Ningbo Key Laboratory of Urban and Rural Water Pollution Control Technology Ningbo315100China

The effect of salinity on biological nitrogen and denitrifying phosphorus removal was investigated in a Modified University of Cape Town(MUCT)system.Removal rates of COD,NH_(4)^(+)-N,NO_(3)^(-)-N,NO_(2)^(-)-N,phosphorus and the sludge characteristics at salt concentrations(0.0,3.2,6.4,11.2 and 16.0 g L^(-1))were analyzed.With the salt concentration increasing,all the COD,NH_(4)^(+)-N,TN and TP removal rates exhibited a trend of decline,and exhibited an initial reduction and subsequent increase at every stage of salt concentration.NH_(4)^(+)-N,TN and TP removal rates were 92.7%,51.5%and 67.2%in 16 g L^(-1) salt concentration,respectively.And they were outperformed the literature reported and acceptable in practical applications.When the salinity of wastewater changed from 0.0 to 16.0 g L^(-1),the biomass yield coefficients increased from 0.0794 to 0.126 g VSS/g COD.Increased salinity had a detrimental effect on phosphorus-accumulating organisms(PAOs)and denitrifying PAOs(DPAOs)(especially DPAOs).Therefore,phosphorus removal gradually depended on PAO.The simultaneous nitrification and denitrification(SND)rate and nitrogen removal rate(including nitrification rate,denitrification rate,and total nitrogen removal rate)gradually decreased with the increased salinity.

关键词： Aquaculture wastewater Denitrifying phosphorus removal MUCT process TP SND rate

Tunable Multicolor Fluorescence of Perovskite-Based Composites for Optical Steganography and Light-Emitting Devices

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Research 2023年第1期2022卷 185-195页

作者： Kewei Ma Qingfeng Gui Cihui Liu Yunyi Yang Fangjian Xing Yunsong Di Xiaoming Wen Baohua Jia Zhixing Gan Center for Future Optoelectronic Functional materials School of Computer and Electronic Information/School of Artificial IntelligenceNanjing Normal UniversityNanjing 210023China College of Naval Architecture and Ocean Engineering Jiangsu Maritime InstituteNanjing 211170China Centrefor Translational Atomaterials Schoolof ScienceSwinburne University of TechnologyJohn Street Hawthon VIC3122Australia School of Science RMIT UniversityMelbourne3000 VICAustralia College of materials Science and Engineering Qingdao University of Science and TechnologyQingdao 266042China

Multicolor fluorescence of mixed halide perovskites enormously enables their applications in photonics and optoelectronics.However,it remains an arduous task to obtain multicolor emissions from perovskites containing single halogen to avoid phase segregation.Herein,a fluorescent composite containing Eu-based metal-organic frameworks(MOFs),OD Cs PbBre,and 3D CsPbBrs is synthesized.Under excitations at 365 nm and 254nm,the pristine composite emits blue(B)and red(R)fluorescence,which are ascribed to radiative defects within CsPbBr and 5Do→7F,transitions of Eu^(3+),respectively.Interestingly,after light soaking in the ambient environment,the blue fluorescence gradually converts into green(G)emission due to the defect repairing and 0D-3D phase conversion.This permanent and unique photochromic effect enables anticounterfeiting and microsteganography with increased security through a micropatterning technique.Moreover,the RGB luminescence is highly stable after encapsulation by a transparent polymer layer.Thus,trichromatic light-emitting modules are fabricated by using the fluorescent composites as color-converting layers,which almost fully cover the standard color gamut.Therefore,this work innovates a strategy for construction of tunable multicolor luminescence by manipulating the radiative defects and structural dimensionality.

关键词： composite composites perovskite

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中国政府经常转移的再分配效应研究

河北经贸大学学报 2016年第1期37卷 61-67页

作者：马克卫山西财经大学统计学院山西太原030006

以中国国民收入再分配流量平衡表为基础,构造部门再分配流量变动的净收支乘数效应模型、部门间关联传递效应乘数模型、部门收入流量波动对再分配交易流量乘数影响模型。结合2012年资金流量表数据,实际计算了政府经常转移变动引致的各部... 详细信息

以中国国民收入再分配流量平衡表为基础,构造部门再分配流量变动的净收支乘数效应模型、部门间关联传递效应乘数模型、部门收入流量波动对再分配交易流量乘数影响模型。结合2012年资金流量表数据,实际计算了政府经常转移变动引致的各部门、各再分配交易流量波动效应。最终的研究结论不仅提供了一种政府经常转移影响效应研究的方法论思路,还能够作为政府经常转移及再分配政策调整的决策参考。

关键词：补贴制度投入产出乘数收入再分配平衡表部门间关联影响国民收入平衡表乘数效应收入再分配

Effects of annealing temperature on the microstructure and hardness of TiAlSiN hard coatings

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Chinese Science Bulletin 2011年第16期56卷 1727-1731页

作者： WANG Xin XU JianHua ma ShengLi XU kewei State Key Laboratory for Mechanical Behavior of materials Xi' an Jiaotong University Xi' an 710049 China

TiAlSiN hard coatings were synthesized on high-speed steel using an arc ion enhanced magnetic sputtering hybrid system.The microstructure and hardness of the coatings at different annealing temperatures were explored by means of XRD,TEM,EDAX and Vickers indentation.The as-deposited TiAlSiN coatings were confirmed to be amorphous due to high depositing rate and low deposition temperature during the film growth.The transformation from amorphous to nanocomposites of nano-crystallites and amorphousness were observed after the annealing treatment,the microstructure of TiAlSiN coatings annealed at 800°C and 1000°C were consisted of crystalline hcp-AlN,fcc-TiN and amorphous phase,however,the coatings were only consisted of fcc-TiN and amorphous phase when annealing at 1100°C and 1200°C.Meanwhile,the formation of Al2O3 was detected on the coating surface after annealing at 1200°C and it indicated the excellent oxidation resistance of the TiAlSiN coatings under the present experimental conditions.Furthermore,the average grain size of the TiAlSiN coatings after high temperature annealing even at 1200°C was less than 30 nm and the size increased with the increasing temperature.However,the hardness of the so-deposited coatings with HV0.2N=3300 dramatically decreased with the increase of temperature and reached nearly to the hardness of TiN coatings with HV0.2N=2300.

关键词：退火温度硬质涂层微观结构硬度 TiN涂层混合动力系统沉积温度纳米复合材料