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Energy Engineering 2022年第5期119卷 2005-2029页

作者： gang lei Chunxiang Xu School of Mechatronics&Vehicle Engineering Zhengzhou University of TechnologyZhengzhou450044China Civil Engineering College Zhengzhou University of TechnologyZhengzhou450044China

In the present paper,the distribution feeder reconfiguration in the presence of distributed generation resources(DGR)and energy storage systems(ESS)is solved in the dynamic *** studies on the reconfiguration problem have ignored the grid security and reliability,the non-distributed energy index along with the energy loss and voltage stability indices has been assumed as the objective functions of the given *** achieve the mentioned benefits,there are several practical plans in the distribution *** of these applications is the network rearrangement plan,which is the simplest and least expensive way to add equipment to the ***,by adding the DGRs to the distribution grid,the radial mode of the grid and the one-sided passage of power are eliminated,and the ordinary and simple grid is replaced with a complex *** this paper,an improved particle clustering algorithm is used to solve the distribution network rearrangement problem with the presence of distributed generation *** PQ model and the PV model are both considered,and for this purpose,a model based on the compensation technique is used to model the PV *** proposed developed model has particularly improved the local and global search of this *** reconfiguration problem is discussed and investigated considering different scenarios in a standard 33-bus grid as a well-known power system in different scenarios in the presence and absence of the ***,the obtained results are compared.

关键词： Reconfiguration distributed generation resources(DGRs) fuzzy modeling developed particle swarm optimization(PSO)algorithm

Species diversification and phylogeographical patterns of birds in response to the uplift of the Qinghai-Tibet Plateau and Quaternary glaciations

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Current Zoology 2014年第2期60卷 149-161页

作者： Fumin lei Yanhua QU gang SONG Key Laboratory of Zoological Systematics and Evolution Institute of Zoology Chinese Academy of Sciences Beijing 100101China

The Qinghai-Tibet Plateau （QTP） is well known for being of great importance in the evolution of montane species due to its unique geological history and landform configuration, climate complexity, and diversified habitats. The effect of environmental changes since the Quaternary on species diversification, population genetic structure, and demography under environmental change can be studied using phylogenetic and phylogeographieal approaches. Birds are the most well-studied group of all terrestrial vertebrates with regard to their response to climatic changes over time. Herein, we briefly review the species diversification of birds in response to the uplift of the QTP, focusing on summarizing the different phylogeographical patterns of birds on the Plateau, its southeastern margin, and the Eastern Himalayas and the reasons underlying these patterns. Speciation was found to be closely related to the uplift of the QTP, with different patterns of intraspecific processes：（1） no divergence within a single refuge was identified in a restricted semi-continuous area of the eastern margin of the Plateau; （2） two divergent lineages with separated refugia were located at the south-eastern and north-eastern margins of the plateau; and （3） multiple divergent lineages within subregions were found in the Eastern Himalayas. Glacial movements and induced climate change are considered to be key factors in shaping these different patterns. The species distributed mainly in the heavily ice-covered platform regions of the Plateau experienced population expansion following the retreat of the extensive glaciations, whereas the species distributed on the ice-free edges of the plateau maintained their population size at a stable level. Demographic stresses on the edge species might have been mitigated by the milder climate in comparison to their platform-distributed counterparts. Various behavioral and ecological characteristics, including dispersal capacity, habitat preference, and eleva

关键词： Qinghai-Tibet Plateau Comparative phylogeography Bird Pleistocene glaciations

Blockchain Meets Generative Behavior Steganography:A Novel Covert Communication Framework for Secure IoT Edge Computing

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Chinese Journal of Electronics 2024年第4期33卷 886-898页

作者： Yuanlong CAO Junjie LI Kailin CHAO Jianmao XIAO gang lei School of Computer Information Engineering Jiangxi Normal University Jiangxi Blockchain Data Security and Governance Engineering Research Center Jiangxi Normal University School of Software Jiangxi Normal University

The rapid development of Internet of things(Io T) and edge computing technologies has brought forth numerous possibilities for the intelligent and digital future. The frequent communication and interaction between devices inevitably generate a large amount of sensitive information. Deploying a blockchain network to store sensitive data is crucial for ensuring privacy and security. The openness and synchronicity of blockchain networks give rise to challenges such as transaction privacy and storage capacity issues, significantly impeding their development in the context of edge computing and Io T. This paper proposes a reliable fog computing service solution based on a blockchain fog architecture. This paper stores data files in the inter planetary file system(IPFS) and encrypts the file hash values used for retrieving data files with stream cipher encryption. It employs a steganographic transmission technique leveraging Alpha Zero's Gomoku algorithm to discretely transmit the stream cipher key across the blockchain network without a carrier, thus achieving dual encryption. This approach aims to mitigate the storage burden on the blockchain network while ensuring the security of transaction data. Experimental results demonstrate that the model enhances the transmission capacity of confidential information from kilobytes(KB) to megabytes(MB) and exhibits high levels of covert and security features.

关键词： Steganography Ciphers Privacy Data privacy Blockchains Encryption Internet of Things

Two-Scale Picard Stabilized Finite Volume Method for the Incompressible Flow

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Advances in Applied Mathematics and Mechanics 2014年第5期6卷 663-679页

作者： Jianhong Yang gang lei Jianwei Yang Department of Mathematics Baoji University of Arts and SciencesBaoji 721013China Department of Computer and Science Baoji University of Arts and SciencesBaoji 721007China

In this paper,we consider a two-scale stabilized finite volume method for the two-dimensional stationary incompressible flow approximated by the lowest equalorder element pair P_(1)−P_(1)which do not satisfy the inf-sup *** two-scale method consist of solving a small non-linear system on the coarse mesh and then solving a linear Stokes equations on the fine *** of the optimal order in the H1-norm for velocity and the L^(2)-norm for pressure are *** error analysis shows there is the same convergence rate between the two-scale stabilized finite volume solution and the usual stabilized finite volume solution on a fine mesh with relation h=O(H^(2)).Numerical experiments completely confirm theoretic ***,this method presented in this paper is of practical importance in scientific computation.

关键词： Incompressible flow stabilized finite volume method inf-sup condition local Gauss integral two-scale method

AN EXPERIMENTAL STUDY ON VERTICAL HYDRODYNAMIC FORCE ON A CIRCULAR SLAB NEAR FREE SURFACE BY WATER WAVES

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Journal of Hydrodynamics 2006年第2期18卷 184-191页

作者： LAN Ya-mei LIU Hua XUE lei-ping CHEN gang School of Naval Architecture Ocean and Civil Engineering Shanghai Jiaotong University Shanghai 200030China

An experimental study has been carried out to investigate the vertical force on a slab of sea-crossing bridge piers in the cases of different hydrodynamic conditions. The experimental study is divided into two parts in terms of regular waves and irregular waves. The hydrodynamic loads acting on the slab are measured by a six component balance and pressures on the bottom of the slab are measured by pressure transducers. It turns out that the vertical lbrce patterns can be considered as impact type and bouyant uplili type. For these two different patterns, time series of the vertical hydrodynamic forcc are measured and analyzed. The influences of wave height, wave period, clearance height of slab on the vertical force arc discussed in detail.

关键词： vertical impact forcc bouyant uplift force,waves slab

Hot Deformation Behavior and Processing Maps of 0.3C-15Cr-1Mo-0.5N High Nitrogen Martensitic Stainless Steel

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Acta Metallurgica Sinica(English Letters) 2020年第5期33卷 693-704页

作者： Xin Cai Xiao-Qiang Hu lei-gang Zheng Dian-Zhong Li Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang 110016China School of Materials Science and Engineering University of Science and Technology of China72 Wenhua RoadShenyang 110016China

Hot deformation behavior of 0.3 C-15 Cr-1 Mo-0.5 N high nitrogen martensitic stainless steel(HNMSS)was investigated in the temperature range of 1173-1473 K and at strain rates of 0.001-10 s-1 using a Gleeble 3500 thermal-mechanical *** true stress-strain curves of the studied HNMSS were measured and corrected to eliminate the effect of friction on the flow *** relationship between the flow stress and Zener-Hollomon parameter for the studied HNMSS wsa analyzed in the Arrhenius hyperbolic sine constitutive model by the law of Z=3.76×1015 sinh(0.004979σp)*** processing maps at different strains of the studied HNMSS were plotted,and its flow instability regions in hot working were also confirmed in combination with the microstructure ***,the optimal hot deformation parameters of the studied HNMSS could be suggested at T=1303-1423 K andε=5-10 s-1 or T=1273-1473 K andε=0.005-0.04 s-1.

关键词： High nitrogen martensitic stainless steel(HNMSS) Hot deformation Processing map Microstructure

Lumped parameter model for resonant frequency estimation of a thermoacoustic engine with gas-liquid coupling oscillation

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第3期12卷 232-237页

作者： Ke TANG Tian lei Xiao-gang LIN Tao JIN Yu ZHANG Institute of Refrigeration and Cryogenics Zhejiang University Hangzhou 310027 China

Gas-liquid coupling oscillation is a novel approach to reducing the resonant frequency and to elevating the pressure amplitude of a thermoacoustic *** a thermoacoustic engine is used to drive low-frequency pulse tube refrigerators,the frequency matching between the thermoacoustic engine and the refrigerator plays an important *** on an acoustic-electric analogy,a lumped parameter model is proposed to estimate the resonant frequency of a standing-wave thermoacoustic engine with gas-liquid coupling ***,a simplified lumped parameter model is also developed to reduce the computation *** resonant frequency dependence on the mean pressure,the gas space volume,and the water column length is computed and *** impact of different working gases on the resonant frequency is also *** effectiveness of the models is validated by comparing the computed results with the experimental data of the gas-liquid coupling oscillation *** increase in the mean working pressure can lead to a rise in the resonant frequency,and a lower resonant frequency can be achieved by elongating the liquid *** comparison with nitrogen and argon,carbon dioxide can realize a lower frequency due to a smaller specific heat ratio.

关键词： Thermoacoustic engine Gas-liquid coupling oscillation Acoustic-electric analogy Resonant frequency

An approximate analytical model for unconventional reservoir considering variable matrix blocks and simultaneous matrix depletion

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Petroleum Science 2024年第1期21卷 352-365页

作者： Kai-Xuan Qiu Jia Li Dong Feng Shi-Ming Wei gang lei Jiangmen Laboratory of Carbon Science and Technology Jiangmen529100GuangdongChina The Hong Kong University of Science and Technology(Guangzhou) Guangzhou511400GuangdongChina China University of Geosciences(Beijing) Beijing100083China China University of Petroleum(Beijing) Beijing102249China China University of Geosciences(Wuhan) Wuhan430074HubeiChina Shenzhen Research Institute China University of GeosciencesShenzhen518063GuangdongChina

In regard to unconventional oil reservoirs,the transient dual-porosity and triple-porosity models have been adopted to describe the fluid flow in the complex fracture *** has been proven to cause inaccurate production evaluations because of the absence of matrix-macrofracture *** addition,most of the existing models are solved analytically based on Laplace transform and numerical ***,an approximate analytical solution is derived directly in real-time space considering variable matrix blocks and simultaneous matrix *** simplify the derivation,the simultaneous matrix depletion is divided into two parts:one part feeding the macrofractures and the other part feeding the ***,a series of partial differential equations(PDEs)describing the transient flow and boundary conditions are constructed and solved analytically by ***,a relationship between oil rate and production time in real-time space is *** new model is verified against classical analytical *** the microfracture system and matrix-macrofracture communication is neglected,the result of the new model agrees with those obtained with the dual-porosity and triple-porosity model,***,the new model also has an excellent agreement with the numerical *** model is then applied to two actual tight oil wells completed in western Canada sedimentary *** identifying the flow regime,the solution suitably matches the field production data,and the model parameters are *** these output parameters,we can accurately forecast the production and even estimate the petrophysical properties.

关键词： Analytical solution Unconventional reservoir Variable matrix Simultaneous flow

Finite-Control-Set Model Predictive Control of Permanent Magnet Synchronous Motor Drive Systems——An Overview

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IEEE/CAA Journal of Automatica Sinica 2022年第12期9卷 2087-2105页

作者： Teng Li Xiaodong Sun gang lei Zebin Yang Youguang Guo Jianguo Zhu Automotive Engineering Research Institute Jiangsu UniversityZhenjiang 212013China IEEE School of Electrical and Data Engineering University of Technology SydneySydney NSW 2007Australia School of Electrical and Information Engineering Jiangsu UniversityZhenjiang 212013China School of Electrical and Information Engineering University of SydneySydney NSW 2006Australia

Permanent magnet synchronous motors(PMSMs)have been widely employed in the industry. Finite-control-set model predictive control(FCS-MPC), as an advanced control scheme, has been developed and applied to improve the performance and efficiency of the holistic PMSM drive systems. Based on the three elements of model predictive control, this paper provides an overview of the superiority of the FCS-MPC control scheme and its shortcomings in current applications. The problems of parameter mismatch, computational burden, and unfixed switching frequency are summarized. Moreover, other performance improvement schemes, such as the multi-vector application strategy, delay compensation scheme, and weight factor adjustment, are reviewed. Finally, future trends in this field is discussed, and several promising research topics are highlighted.

关键词： Computational burden finite control set(FCS) model predictive control(MPC) permanent magnet synchronous motor(PMSM) robust operation switching frequency

Effect of Intergranular Precipitation on the Internal Oxidation Behavior of Cr–Mn–N Austenitic Stainless Steels

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Acta Metallurgica Sinica(English Letters) 2015年第8期28卷 1008-1014页

作者： lei-gang Zheng Xiao-Qiang Hu Xiu-Hong Kang Dian-Zhong Li Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences

The effect of intergranular precipitation on the internal oxidation behavior of Cr–Mn–N austenitic steels at 1000 °C in dry air atmosphere was investigated using scanning electron microscope, transmission electron microscope, and X-ray diffraction analysis. The results show that intergranular M23C6 carbide morphologies play an important role on the internal oxidation behavior of Cr–Mn–N steels. During the period of the oxidation, both discontinuous chain-shaped and continuous film-shaped intergranular M23C6 carbides precipitated along the grain boundaries. Internal oxides of silica preferentially intruded into the matrix along grain boundaries with discontinuous M23C6 carbide particles, while silica was obviously restricted at the interfaces between the external scale and matrix on the occasion of continuous film-shaped M23C6 carbides. It is seemed that reasonable microstructure could improve the oxidation resistance of Cr–Mn–N steels.

关键词： M23C6 precipitation Internal oxidation Cr–Mn–N austenitic steel