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A FRAMEWORK FOR REAL-VALUED CIPHER SYSTEMS

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Journal of Systems Science & Complexity 2007年第4期20卷 486-491页

作者： Zhaozhi ZHANG nan jiang Institute of Systems Science Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China College of Computer Science and Technology Beijing University of Technology Beijing 100022 China

Most cipher systems designed thus far are binary-valued or integer-valued cipher systems. Their security relies on the assumption that one-way functions exist. Though the existence of one-way functions has not been proved yet, most cryptographic researchers believe that one-way functions exist. In addition, many candidates for one-way functions have been proposed. Therefore, the key step for developing real-valued cipher systems is to define real one-way functions and to propose candidates for them. In this paper, based on computational complexity theory over the real field, we give two definitions of real one-way functions; one is for digital one-way functions and the other is for general one-way functions. Candidates for these two classes of one-way functions are also proposed. Moreover, we present two examples to demonstrate that the candidates for both digital one-way functions and general one-way functions can be applied to construct secure real-valued cipher systems.

关键词： Computational complexity theory digital one-way function general one-way function real-valued cipher system.

Precise tracking of tip-induced structural variation at the single-chemical-bond limit

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Light(Science & Applications) 2023年第1期12卷 15-16页

作者： Sayantan Mahapatra nan jiang Department of Chemistry University of Illinois ChicagoChicagoIL 60607USA

Sub-nanometer-resolved TERS provides a systematic way for investigating tip-molecule interaction and molecular motions,enabling a promising approach to examine on-surface reaction mechanisms and catalysis at the micro... 详细信息

关键词： level. limit catalysis

Research on Voiceprint Recognition of Camouflage Voice Based on Deep Belief Network

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International Journal of Automation and computing 2021年第6期18卷 947-962页

作者： nan jiang Ting Liu College of Public Security Information Technology and Intelligence Criminal Investigation Police University of ChinaShenyang 110854China College of Light Industry Liaoning UniversityShenyang 110036China

The problem of disguised voice recognition based on deep belief networks is studied. A hybrid feature extraction algorithm based on formants, Gammatone frequency cepstrum coefficients(GFCC) and their different coefficients is proposed to extract more discriminative speaker features from the original voice data. Using mixed features as the input of the model, a masquerade voice library is constructed. A masquerade voice recognition model based on a depth belief network is proposed. A dropout strategy is introduced to prevent overfitting, which effectively solves the problems of traditional Gaussian mixture models, such as insufficient modeling ability and low discrimination. Experimental results show that the proposed disguised voice recognition method can better fit the feature distribution, and significantly improve the classification effect and recognition rate.

关键词： Disguised voice recognition deep belief network feature extraction Gammatone frequency cepstrum coefficients(GFCC) dropout

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Battery Separators Functionalized with Edge-Rich MoS2/C Hollow Microspheres for the Uniform Deposition of Li2S in High-Performance Lithium-Sulfur Batteries

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nano-Micro Letters 2019年第3期11卷 104-118页

作者： nan Zheng Guangyu jiang Xiao Chen Jiayi Mao nan jiang Yongsheng Li Lab of Low-Dimensional Materials Chemistry Key Laboratory for Ultrafine Materials of Ministry of Education Shanghai Engineering Research Center of Hierarchical Nanomaterials School of Materials Science and Engineering East China University of Science and Technology

As promising energy storage systems,lithium-sulfur(Li-S)batteries have attracted significant attention because of their ultra-high energy ***,Li-S battery suffers problems related to the complex phase conversion that occurs during the charge-discharge process,particularly the deposition of solid Li2S from the liquid-phase polysulfides,which greatly limits its practical *** this paper,edge-rich MoS2/C hollow microspheres(Edg-MoS2/C HMs)were designed and used to functionalize separator for Li-S battery,resulting in the uniform deposition of *** microspheres were fabricated through the facile hydrothermal treatment of MoO3-aniline nanowires and a subsequent carbonization *** obtained Edg-MoS2/C HMs have a strong chemical absorption capability and high density of Li2S binding sites,and exhibit excellent electrocatalytic performance and can effectively hinder the polysulfide shuttle effect and guide the uniform nucleation and growth of ***,we demonstrate that the Edg-MoS2/C HMs can effectively regulate the deposition of Li2S and significantly improve the reversibility of the phase conversion of the active sulfur species,especially at high sulfur loadings and high *** a result,a cell containing a separator functionalized with Edg-MoS2/C HMs exhibited an initial discharge capacity of 935 mAh g-1 at 1.0 C and maintained a capacity of 494 mAh g-1 after 1000 cycles with a sulfur loading of 1.7 mg ***,at a high sulfur loading of 6.1 mg cm-2 and high rate of 0.5 C,the cell still delivered a high reversible discharge capacity of 478 mAh g-1 after 300 *** work provides fresh insights into energy storage systems related to complex phase conversions.

关键词： Edge-rich MoS2/C Hollow microspheres Li2S Lithium-sulfur batteries

Cell-free synthetic biology in the new era of enzyme engineering

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Chinese Journal of Chemical Engineering 2020年第11期28卷 2810-2816页

作者： nan jiang Lianju Ma Yuan Lu College of Life Sciences Shenyang Normal UniversityShenyang 110034China Key Lab of Industrial Biocatalysis Ministry of EducationDepartment of Chemical EngineeringTsinghua UniversityBeijing 100084China

With the gradual rise of enzyme engineering,it has played an essential role in synthetic biology,medicine,and ***,due to the limitation of the cell membrane,the complexity of cellular metabolism,the difficulty of controlling the reaction environment,and the toxicity of some metabolic products in traditional in vivo enzyme engineering,it is usually problematic to express functional enzymes and produce a high yield of synthesized ***,cell-free synthetic biology methods for enzyme engineering have been proposed as alternative *** cell-free method has no limitation of the cell membrane and no need to maintain cell viability,and each biosynthetic pathway is highly *** property makes cell-free approaches suitable for the production of valuable products such as functional enzymes and chemicals that are difficult to *** article aims to discuss the latest advances in cell-free enzyme engineering,assess the trend of this developing topical filed,and analyze its prospects.

关键词： Cell-free synthetic biology Enzyme engineering Metabolic engineering

Tomographic TR-PIV measurement of coherent structure spatial topology utilizing an improved quadrant splitting method

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Science China(Physics,Mechanics & Astronomy) 2012年第10期55卷 1863-1872页

作者： YANG ShaoQiong jiang nan Department of Mechanics School of Mechanical EngineeringTianjin UniversityTianjin 300072China State Key Laboratory of Non-linear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100080China Tianjin Key Laboratory of Modern Engineering Mechanics Tianjin 300072China

In this paper,we calculated the spatial local-averaged velocity strains along the streamwise direction at four spatial scales according to the concept of spatial local-averaged velocity structure function by using the three-dimensional three-component database of time series of velocity vector field in the turbulent boundary layer measured by tomographic time-resolved particle image *** improved quadrant splitting method,based on the spatial local-averaged velocity strains together with a new conditional sampling phase average technique,was introduced as a criterion to detect the coherent structure ***,we used them to detect and extract the spatial topologies of fluctuating velocity and fluctuating vorticity whose center is a strong second-quadrant event(Q2) or a fourth-quadrant event(Q4).Results illustrate that a closer similarity of the multi-scale coherent structures is present in the wall-normal direction,compared to the one in the other two *** relationship among such topological coherent structures and Reynolds stress bursting events,as well as the fluctuating vorticity was *** other burst events are surveyed(the first-quadrant event Q1 and the third-quadrant event Q3),a fascinating bursting period circularly occurs:Q4-S-Q2-Q3-Q2-Q1-Q4-S-Q2-Q3-Q2-Q1 in the center of such topological structures along the streamwise *** addition,the probability of the Q2 bursting event occurrence is slightly higher than that of the Q4 event *** spatial instable singularity that almost simultaneously appears together with typical Q2 or Q4 events has been observed,which is the main character of the mutual induction mechanism and vortex auto-generation mechanism explaining how the turbulence is produced and maintained.

关键词： turbulent boundary layer coherent structure burst TR-PIV Q2/Q4 local-averaged velocity strain quadrant splittingmethod

Anonymous authentication protocol for multi-services in wireless environments

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The Journal of China Universities of Posts and Telecommunications 2008年第4期15卷 69-74页

作者： jiang nan WANG Jian College of Computer Science Beijing University of Technology Beijing 100124 China School of Computer and Information Technology Beijing Jiaotong University Beijing 100044 China Information Security Center State Key Laboratory of Networking and Switching TechnologyBeijing University of Posts and Telecommunications Beijing 100876 China

To provide mutual authentication among users, wireless networks, and service providers in roaming wireless environments, this article presents an anonymous authentication and access control protocol. Bases on this protocol, entities of different trusted domains can mutually authenticate each other and preserve the anonymity of users. Hybrid cryptosystem, secret splitting, and hash chains are used in the protocol, which decrease computational loads and establish trusted relations for both entities. The proposed protocol has the least computation complexity compared with other protocols, whereas, the security has been significantly improved.

关键词： authentication wireless networks trusted domain secret splitting hash chain

Dynamic mode decomposition of hairpin vortices generated by a hemisphere protuberance

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Science China(Physics,Mechanics & Astronomy) 2012年第1期55卷 118-124页

作者： TANG ZhanQi jiang nan Department of Mechanics Tianjin University Tianjin 300072 China Tianjin Key Laboratory of Modern Engineering Mechanics Tianjin 300072 China

We present dynamic mode decomposition (DMD) for studying the hairpin vortices generated by hemisphere protuberance measured by two-dimensional (2D) time-resolved (TR) particle image velocimetry (PIV) in a water channel. The hairpins dynamic information is extracted by identifying their dominant frequencies and associated spatial structures. For this quasi-periodic data system, the resulting main Dynamic modes illustrate the different spatial structures associated with the wake vortex region and the near-wall region. By comparisons with proper orthogonal decomposition (POD), it can be concluded that the dynamic mode concentrates on a certain frequency component more effectively than the mode determined by POD. During the analysis, DMD has proven itself a robust and reliable algorithm to extract spatial-temporal coherent structures.

关键词： hairpin vortices hemisphere protuberance time-resolved particle image velocimetry dynamic mode decomposition proper orthogonal decomposition

Dynamics Evolution Investigation of Mack Mode Instability in a Hypersonic Boundary Layer by Bicoherence Spectrum Analysis

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Chinese Physics Letters 2012年第7期29卷 171-174页

作者： HAN Jian jiang nan Department of Mechanics Tianjin UniversityTianjin 300072 Department of Mathematics Tianjin UniversityTianjin 300072 Tianjin Key Laboratory of Modern Engineering Mechanics Tianjin 300072

The instability of a hypersonic boundary layer on a cone is investigated by bicoherence spectrum *** experiment is conducted at Mach number 6 in a hypersonic wind *** time series signals of instantaneous fluctuating surface-thermal-flux are measured by Pt-thin-film thermocouple temperature sensors mounted at 28 stations on the cone surface along streamwise direction to investigate the development of the unstable *** bicoherence spectrum analysis based on wavelet transform is employed to investigate the nonlinear interactions of the instability of Mack modes in hypersonic laminar boundary layer *** results show that wavelet bicoherence is a powerful tool in studying the unstable mode nonlinear interaction of hypersonic laminar-turbulent *** first mode instability gives rise to frequency shifts to higher unstable modes at the early stage of hypersonic laminar-turbulent *** modulations subsequently lead to the second mode instability *** second mode instability governs the last stage of instability and final breakdown to turbulence with multi-scale disturbances growth.

关键词： transition laminar turbulent