检索结果-南通市图书馆

Chinese Optics Letters 2022年第7期20卷 52-56页

作者： Penglong Ren Shangming Wei Pu Zhang xue-wen Chen school of Physics and Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan 430074China Institute for Quantum science and engineering Huazhong University of Science and TechnologyWuhan 430074China

Quantum efficiency is a critical piece of information of a quantum emitter and regulates the emitter’s fluorescence decay dynamics in an optical environment through the Purcell ***,we present a simple way to experimentally probe fluorescence quantum efficiency of single dibenzoterrylene molecules embedded in a thin anthracene microcrystal obtained through a co-sublimation *** particular,we correlate the fluorescence lifetime change of single dibenzoterrylene molecules with the variation of the matrix thickness due to natural *** the identification of the molecule emission dipole orientation,we could deduce the near-unity intrinsic quantum efficiency of dibenzoterrylene molecules in the anthracene matrix.

关键词： quantum emitter single-molecule spectroscopy quantum efficiency single-photon source

Performance analysis for a two-way relaying power line network with analog network coding

在线全文

学校读者我要写书评

暂无评论

Frontiers of information Technology & Electronic engineering 2015年第10期16卷 892-898页

作者： Yu-wen QIAN Meng TIAN xue JIANG Hua-ju SONG Feng SHU Jun LI school of Electronic and Optical engineering Nanjing University of Science and Technology school of Biochemical and Environmental engineering Nanjing Xiao Zhuang University

In this paper, we investigate a two-way relaying power line communication （PLC） network with analog network coding. We focus on the analysis of the system outage probability, symbol error rate, and average capacity. Specifically, we first derive the probability density function （PDF） of the received signal-to-noise ratio （SNR） with a closed form, by exploiting the statistical properties of the PLC channel. Then with the help of this PDF, we develop the outage probability, symbol error rate, and average capacity with closed forms, based on the Hermite polynomial. Simulations show that the derived analytical results are consistent with those by Monte Carlo simulation.

关键词： Power line communication Outage probability Symbol error rate Signal attenuation

Lom： Discovering Logic Flaws Within MongoDB-based Web Applications

在线全文

学校读者我要写书评

暂无评论

International Journal of Automation and computing 2017年第1期14卷 106-118页

作者： Shuo wen Yuan xue Jing Xu Li-Ying Yuan wen-Li Song Hong-Ji Yang Guan-Nan Si Institute of Machine Intelligence College of Computer and Control Engineering Nankai University Tianjin 300350 China Department of Electrical engineering and Computer science Vanderbilt University Nashville Tennessee 37212 USA Centre for Creative Computing Bath Spa University Bath BA2 9BN UK school of information science and Electrical engineering Shandong Jiaotong University Ji'nan 250357 China

Logic flaws within web applications will allow malicious operations to be triggered towards back-end database. Existing approaches to identifying logic flaws of database accesses are strongly tied to structured query language （SQL） statement construction and cannot be applied to the new generation of web applications that use not only structured query language （NoSQL） databases as the storage tier. In this paper, we present Lom, a black-box approach for discovering many categories of logic flaws within MongoDB- based web applications. Our approach introduces a MongoDB operation model to support new features of MongoDB and models the application logic as a mealy finite state machine. During the testing phase, test inputs which emulate state violation attacks are constructed for identifying logic flaws at each application state. We apply Lom to several MongoDB-based web applications and demonstrate its effectiveness.

关键词： Logic flaw web application security not only structured query language (NoSQL) database black-box MougoDB.

End-to-end delay analysis for networked systems

在线全文

学校读者我要写书评

暂无评论

Frontiers of information Technology & Electronic engineering 2015年第9期16卷 732-743页

作者： Jie SHEN wen-bo HE xue LIU Zhi-bo WANG Zhi WANG Jian-guo YAO Department of Control science and engineering Zhejiang University school of Computer science Mc Gill University school of Computer Wuhan University Su zhou Institute of Wuhan University school of Software Shanghai Jiao Tong University

End-to-end delay measurement has been an essential element in the deployment of real-time services in networked systems. Traditional methods of delay measurement based on time domain analysis, however, are not efficient as the network scale and the complexity increase. We propose a novel theoretical framework to analyze the end-to-end delay distributions of networked systems from the frequency domain. We use a signal flow graph to model the delay distribution of a networked system and prove that the end-to-end delay distribution is indeed the inverse Laplace transform of the transfer function of the signal flow graph. ~vo efficient methods, Cramer＇s rule-based method and the Mason gain rule-based method, are adopted to obtain the transfer function. By analyzing the time responses of the transfer function, we obtain the end-to-end delay distribution. Based on our framework, we propose an efficient method using the dominant poles of the transfer function to work out the bottleneck links of the network. Moreover, we use the framework to study the network protocol performance. Theoretical analysis and extensive evaluations show the effectiveness of the proposed approach.

关键词： Networked system End-to-end Delay distribution

Analyzing multi-circular loop scatterers by Maxwellian circuits

在线全文

学校读者我要写书评

暂无评论

Journal of Shanghai University(English Edition) 2011年第1期15卷 54-57页

作者：沈文辉薛昌伟梅冠香孟春香林嘉宏 Key Laboratory of Specialty Fiber Optics and Optical Access Networks School of Communication and Information Engineering Shanghai University Department of Electronic engineering City University of Hong Kong

Calculating the current distribution in circular loop scatterers commonly involves complicated computation. In this paper, based on the theory of Maxwellian circuits （MC）, we propose a fast algorithm by solving a wave equation with constant parameters corresponding to the circular loop. Our method prodeces similar results compared to the methods using method of moments （MoM） with lower computational complexity. It is effective when there are parallel multiple circular loop scatterers. Experimental results show accuracy of the method.

关键词： circular loop scatterer theory of Maxwellian circuits (MC) method of moments (MoM)

Irrational-Behavior-Proof Conditions Based on Limit Characteristic Functions

在线全文

学校读者我要写书评

暂无评论

Journal of Systems science and information 2019年第1期10卷 1-16页

作者： Cui LIU Hongwei GAO Ovanes PETROSIAN juan xue Lei WANG school of Mathematics and Statistics Qingdao University school of Mathematics and Statistics Institute of Applied Mathematics of ShandongQingdao University Faculty of Applied Mathematics and Control Processes Saint Petersburg State University school of Mathematics and Statistics College of Automation and Electrical EngineeringQingdao University

Irrational-behavior-proof(IBP) conditions are important aspects to keep stable cooperation in dynamic cooperative games. In this paper, we focus on the establishment of IBP ***, the relations of three kinds of IBP conditions are described. An example is given to show that they may not hold, which could lead to the fail of cooperation. Then, based on a kind of limit characteristic function, all these conditions are proved to be true along the cooperative trajectory in a transformed cooperative game. It is surprising that these facts depend only upon the individual rationalities of players for the Shapley value and the group rationalities of players for the core. Finally,an illustrative example is given.

关键词： dynamic cooperative game irrational-behavior-proof condition limit characteristic function individual rationality

A new energy landscape paving heuristic for satellite module layouts

在线全文

学校读者我要写书评

暂无评论

Frontiers of information Technology & Electronic engineering 2016年第10期17卷 1031-1043页

作者： Jing-fa LIU juan HUANG Gang LI wen-jie LIU Ting-zhao GUAN Liang HAO Jiangsu engineering Center of Network Monitoring Nanjing University of Information Science & Technology Nanjing 210044 China school of Computer & Software Nanjing University of Information Science & Technology Nanjing 210044 China school of Mathematics and Statistics Nanfing University of Information Science & Technology Nanjing 210044 China Office of lnformationization Construction and Management Nanjing University of lnformation Science & Technology Nanjing 210044 China

This article describes a study of the satellite module layout problem （SMLP）, which is a three-dimensional （3D） layout optimization problem with performance constraints that has proved to be non-deterministic polynomial-time hard （NP-hard）. To deal with this problem, we convert it into an unconstrained optimization problem using a quasi-physical strategy and the penalty function method. The energy landscape paving （ELP） method is a class of Monte-Carlo-based global optimization algorithm that has been successfully applied to solve many optimization problems. ELP can search for low-energy layouts via a random walk in complex energy landscapes. However, when ELP falls into the narrow and deep valleys of an energy landscape, it is difficult to escape. By putting forward a new update mechanism of the histogram function in ELP, we obtain an improved ELP method which can overcome this drawback. By incorporating the gradient method with local search into the improved ELP method, a new global search optimization method, hELP, is proposed for SMLP. Two representative instances from the literature are tested. Computational results show that the proposed hELP algorithm is an effective method for solving SMLP with performance constraints.

关键词： Three-dimensional packing Energy landscape paving Layout optimization Performance constraints

Effects of different types of biochar on the properties and reactivity of nano zero-valent iron in soil remediation

在线全文

学校读者我要写书评

暂无评论

Frontiers of Environmental science & engineering 2021年第5期15卷 257-269页

作者： Chengjie xue juan Wu Kuang Wang Yunqiang Yi Zhanqiang Fang wen Cheng Jianzhang Fang school of Environment South China Normal UniversityGuangzhou510006China Institute of Environmental sciences(CML) Leiden UniversityLeiden2300 RAThe Netherlands Guangdong Technology Research Center for Ecological Management and Remediation of Water System Guangzhou510006China Guangdong Provincial Key Laboratory of Chemical Pollution&Environmental Safety Guangzhou510006China

The addition of nano zero-valent iron(nZVI)is a promising technology for the in situ remediation of ***,the mobility and,consequently,the reactivity of nZVI particles in contaminated areas decrease due to their rapid *** this study,we determined how nZVI particles can be stabilized using different types of biochar(BC)as a support(BC@nZVI).In addition,we investigated the transport behavior of the synthesized BC@nZVI particles in a column filled with porous media and their effectiveness in the removal of BDE209(decabromodiphenyl ether)from *** characterization results of N2 Brunauer-Emmett-Teller(BET)surface area analyses,scanning electron microscopy(SEM),X-ray diffraction(XRD)and Fourier transform infrared spectroscopy(FTIR)indicated that nZVI was successfully loaded into the *** sedimentation test results and the experimental breakthrough curves indicated that all of the BC@nZVI composites manifested better stability and mobility than did the bare-nZVI particles,and the transport capacity of the particles increased with increasing flow velocity and porous medium ***,the maximum concentrations of the column effluent for bagasse-BC@nZVI(B-BC@nZVI)were 19%,37%and 48%higher than those for rice straw-BC@nZVI(R-BC@nZVI),wood chips-BC@nZVI(W-BC@nZVI)and corn stalks-BC@nZVI(C-BC@nZVI),respectively.A similar order was found for the removal and debromination efficiency of decabromodiphenyl ether(BDE209)by the aforementioned ***,the attachment of nZVI particles to BC significantly increased the reactivity,stability and mobility of B-BC@nZVI yielded,and nZVI the best performance.

关键词： Nano zero-valent iron Biochar BDE209 Transport Soil

同方期刊数据库

New Terms for Compact Form of Electroweak Chiral Lagrangian

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2008年第3期49卷 723-724页

作者： ZHANG Hong-Hao YAN wen-Bin J.K. Parry LI xue-Song school of Physics and engineering Sun Yet-Sen University Gunagzhou 510275 China Center for High Energy Physics ＆ Department of Physics Tsinghua University Beijing 100084 China science College Hunan Agricultural University Changsha 410128 China Department of Physics and Astronomy State University of New York at Stony Brook New York 11794 USA

The compact form of the electroweak chiral Lagrangian is a reformulation of its original form and is expressed in terms of chiral rotated electroweak gauge fields, which is crucial for relating the information of underlying theories to the coefficients of the low-energy effective Lagrangian. However the compact form obtained in previous works is not complete. In this letter we add several new chiral invariant terms to it and discuss the contributions of these terms to the original electroweak chiral Lagrangian.

关键词： electroweak chiral Lagrangian beyond standard model

Enhancement of cooperation between file systems and applications — VFS extensions for optimized performance

在线全文

学校读者我要写书评

暂无评论

science china(information sciences) 2015年第9期58卷 46-55页

作者： WANG Li LIAO XiangKe xue JingLing WEIL Sage wen YunChuan YANG xueJun school of Computer science and Technology National University of Defense Technology school of Computer science and engineering University of New South Wales

Modern operating systems incorporate an abstract layer called Virtual File System(VFS), which is positioned between user applications and real file systems to hide the differences of various file systems and to expose generic application interfaces for requesting file system services. However, VFS sometimes does not give applications an opportunity to pass information to file systems to help them make correct optimization decisions. In this paper, we review the Linux VFS, discuss its deficiencies and propose several extensions to allow applications to cooperate with the file systems more efficiently. We introduce simple prefetching interfaces and advisory flags to allow applications to communicate application-related semantics to VFS and/or the underlying file systems. These suggestions, which neither affect the semantics of applications nor modify their programming models, not only lead to simple VFS/file systems but also guide them to make correct performance-related decisions, if required. We demonstrate that these interfaces and flags are also easy to implement and can boost application performance by up to 4.29 X.

关键词： virtual file system metadata cache dentry cache page cache page readahead