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锂金属负极固态电解质界面膜形成和生长机理的理论研究进展

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储能科学与技术 2024年第9期13卷 3150-3160页

作者：周国兵许审镇北京大学材料科学与工程学院北京100871 江西师范大学化学工程学院江西南昌330022

锂金属负极因其极高的理论比容量在锂离子电池领域引起了极大的关注,但其高反应活性会引发电解液组分发生一系列复杂的降解反应,并在电极表面生成固态电解质界面膜(SEI)。SEI钝化层一方面能抑制电解液持续损耗,另一方面也会显著影响电... 详细信息

锂金属负极因其极高的理论比容量在锂离子电池领域引起了极大的关注,但其高反应活性会引发电解液组分发生一系列复杂的降解反应,并在电极表面生成固态电解质界面膜(SEI)。SEI钝化层一方面能抑制电解液持续损耗,另一方面也会显著影响电池的循环性能。因此,从原子/分子层面阐明SEI形成和生长机理成为了近些年的研究重点和热点。本文综述了不同理论模拟方法在SEI结构、组分和生长过程的最新研究进展,介绍了经典分子动力学、反应力场分子动力学、第一性原理分子动力学、机器学习力场分子动力学以及动力学蒙特卡罗等模拟方法在SEI研究中的成功案例。讨论了现有理论计算方法在模拟SEI形成和生长机理方面的局限性,提出可结合机器学习和动力学蒙特卡罗方法来实现长时域SEI形成和生长过程模拟的技术方案展望。

关键词：固态电解质界面膜形成和生长机理分子动力学动力学蒙特卡罗机器学习

Dynamic learning rates algorithm for BPNN to forecast time series of dam security

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Progress in Natural Science:Materials International 2007年第12期17卷 1527-1530页

作者： Hu Daiping1, Wu Ruiming1, Lei Aizhong1 and Wang Qi2.1. Antai College of Economics & Management, Shanghai Jiaotong university, Shanghai 2.0052. china 2. {2. School, Lanzhou university, Lanzhou 730000, china) Antai College of Economics & Management Shanghai Jiaotong University Shanghai 200052 China graduate School Lanzhou University Lanzhou 730000 China

Time series data of dam security have a large number of observed values and should be forecasted accurately in time. Neural networks have the powerful approach ablilities of arbitrary functions and have been broadly utilized in many domains. In this paper, a dynamic learning rate training algorithm of back-propagation neural networks for time series forecasting is proposed and the networks with this algorithm are built to forecast time series of dam security. The application results demonostrate the efficiency of modelling and the effictiveness of forecasting.

关键词： neural network dynamic learning rate forecasting dam security.

Statistical distribution of nonlinear random wave height

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Science china Earth Sciences 2006年第4期49卷 443-448页

作者： HOU Yijun1, GUO Peifang1,2. SONG Guiting1,2. SONG Jinbao1, YIN Baoshu1 & ZHAO Xixi1,2.1. Institute of Oceanology, Chinese Academy of Sciences, Qingdao 2.6071, china 2. graduate {2. of the Chinese Academy of Sciences, Beijing 100039, china 1. Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China 2. graduate university of the Chinese Academy of Sciences Beijing 100039 China

A statistical model of random wave is developed using Stokes wave theory of water wave dynamics. A new nonlinear probability distribution function of wave height is presented. The results indicate that wave steepness not only could be a parameter of the distribution function of wave height but also could reflect the degree of wave height distribution deviation from the Rayleigh distribution. The new wave height distribution overcomes the problem of Rayleigh distribution that the prediction of big wave is overestimated and the general wave is underestimated. The prediction of small probability wave height value of new distribution is also smaller than that of Rayleigh distribution. Wave height data taken from East china Normal university are used to verify the new distribution. The results in- dicate that the new distribution fits the measurements much better than the Rayleigh distribution.

关键词： Random ocean wave, nonlinearity, wave height distribution.

Simulation study of phase retrieval for hard X-ray in-line phase contrast imaging

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Science china(Physics,Mechanics & Astronomy) 2005年第4期48卷 450-458页

作者： YU Bin1,2. PENG Xiang1,2. TIAN Jindong1, NIU Hanben1, DIAO Luhong3 & LI Hua3 1. Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education, Institute of Optoelec- tronics, shenzhen university, shenzhen 518060, china 2. State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin university, Tianjin 300072.china 3. Key Laboratory of Intelligent Information Processing, Institute of Computing Technology, Chinese Academy of Sciences, Beijing 100080,china 1. Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education Institute of Optoelectronics Shenzhen University 518060 Shenzhen China 2. State Key Laboratory of Precision Measuring Technology and Instruments Tianjin University 300072 Tianjin China 3. Key Laboratory of Intelligent Information Processing Institute of Computing Technology Chinese Academy of Sciences 100080 Beijing China

Two algorithms for the phase retrieval of hard X-ray in-line phase contrast imaging are presented. One is referred to as Iterative Angular Spectrum Algorithm (IASA) and the other is a hybrid algorithm that combines IASA with TIE (transport of intensity equation). The calculations of the algorithms are based on free space propagation of the angular spectrum. The new approaches are demonstrated with numerical simulations. Comparisons with other phase retrieval algorithms are also performed. It is shown that the phase retrieval method combining the IASA and TIE is a promising technique for the application of hard X-ray phase contrast imaging.

关键词： X-ray optics, phase contrast imaging, phase retrieval, angular spectrum, hard X-ray.

Predicting the behavior of large scale P2. systems by parallel discrete event simulation

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Science china(Information Sciences) 2010年第6期53卷 1109-1121页

作者： ZHENG WeiMin1,YU HongLiang1,SHI GuangYu2.& CHEN Jian2.1Department of Computer Science and Technology,tsinghua university,Beijing 100084,{2. 2.uawei Technologies Co.,Ltd,shenzhen 51812.,{2. 1. Department of Computer Science and Technology Tsinghua University Beijing 100084 China2. Huawei Technologies Co. Ltd Shenzhen 518129 China

P2. systems are becoming the dominator of *** systems are typically composed of thousands to millions of physical computers,which make it difficult to predict their behaviors without a large scale distributed system *** paper is an attempt to predict the behavior of large scale P2. systems by building a novel parallel simulator:AegeanSim,which provides parallel discrete event simulation of such systems on high performance server *** abstract the execution of P2. applications with a specific event model,and parallel the simulation of events in a cluster,thus expanding the simulation scale and boosting the simulation process dramatically.A 1-stage synchronization method is proposed to improve the *** event callback interface is designed to implement their application logic easily while keeping the simulator *** use AegeanSim to predict the behavior of a typical P2. system:*** comparing the simulation behavior of BT with that of related BT studies and verifying its efficiency,scalability and accuracy,we make predictions about the behavior of BT system assuming they are assaulted by different man-made system *** reasonable results are found:(1) Tracker isolation can hardly work because of its short attacking time window.(2. Limiting the bandwidth of BT may be an efficient way to control it.

关键词： P2. simulation parallel

Contour representation based on wedgelet

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Journal of Systems Engineering and Electronics 2006年第2期17卷 251-257页

作者： Liu Zeyi~1, Sun Ziqiang~ 2.3 , Xu Ling~2.& Peng Xiang~ 4,5 1. Dept. of Mathematics of Science Coll., shenzhen Univ., shenzhen 518060, P.R.{2. 2. Dept. of Mathematics of Science Coll., Tianjin Univ., Tianjin 300072. P.R. Ch ina 3.Tianjin Foreign Studies Univ., Tianjin 3002.4, P.R.{2. 4. Inst. of Optoelectronics, shenzhen Univ., shenzhen 518060, P.R.{2. 5. National Lab of Precision Measurement Technology and Instrumentation, Tianjin 300072. P.R.{2. Dept. of Mathematics of Science Coll. Shenzhen Univ. Shenzhen 518060 P. R. China Dept. of Mathematics of Science Coll. Tianjin Univ. Tianjin 300072 P. R. China Tianjin Foreign Studies Univ. Tianjin 300204 P. R. China Inst. of Optoelectronics Shenzhen Univ. Shenzhen 518060 P. R. China National Lab of Precision Measurement Technology and Instrumentation Tianjin 300072 P. R. China

Aiming at the shortcomings of the existing wedgelet compression arithmetics, a novel contour-representing algorithm based on wedgelets is presented in this paper. Firstly the input image is binarized and the most optimized wedgelets are found by means of quadtree framework. Then the contours are reconstructed by applying the wedgelets, the data volume is compressed, and the shortcomings of the contour representation based on normal wavelet are ameliorated, the better effect for the visualization is obtained, too.

关键词： wedgelet binarization quadtree.

The deep thermal characteristic of continental margin of the northern South china Sea

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Chinese Science Bulletin 2000年第18期45卷 1717-1722页

作者： ZHANG Jian & WANG Jiyang1. graduate School, university of Science and Technology of{2., Chinese Academy of Sciences, Beijing 100039,{2. 2. Institute of Geology, Chinese Academy of Sciences, Beijing 10002.,{2. graduate School University of Science and Technology of China Chinese Academy of Sciences Beijing China Institute of Geology Chinese Academy of Sciences Beijing China

Heat flow plays an important role in the study ot thermal structure and thermal evolutionof continental margin of the northern South china Sea. The analysis of heat flow value shows that margin heat flow in the northern South china Sea is relatively high setting, but the percentage of crustal heat flow is lower than 35% in terrestrial heat flow. The terrestrial heat flow exhibited a current of rise from the Northern Continental Margin to the Southern Central Basin. However, the proportion of crustal heat flow in terrestrial heat flow slowly dropped down in the same direction. It is suggested that the main factor causing high heat flow setting is the moving up of hot material from asthenosphere.

关键词： margin of northern South china Sea terrestrial heat flow thermal structures.

Nonlinear interactions between gravity waves and background winds

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Progress in Natural Science:Materials International 2007年第6期17卷 639-644页

作者： Liu Xiao1,2.and Xu Jiyao1(1. State Key Laboratory for Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100080, china 2. graduate {2. of Chinese Academy of Sciences, Beijing 100039, china) [a]State Key Laboratory for Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing China [b]graduate university of Chinese Academy of Sciences Beijing China

Using the nonlinear propagating gravity waves (GW) model in the two-dimensional compressible atmosphere and the linear GW theory, the process of GW propagation in different background winds, e.g. the direction of the background wind is opposite to (dead wind) or the same as (tail wind) the direction of the horizontal phase velocity of GW, is studied. The results show that the dead wind prolongs the vertical wavelength and accelerates GW propagation. Therefore, GW propagates up to a higher height becomes instable in a short time and eventually induces an inverse jet flow. Then, the vertical wavelength is becoming short due to the nonlinear interactions between GW and the inverse jet flow. The vertical wavelength and group velocity decrease after GW propagates into the tail wind. The initial instable time is delayed. Although most of GW is trapped in the instable region, some of GW propagates above the instable region. Compared with GW propagation in the tail wind, the nonlinear interactions between GW and the dead wind are also strong. In contrast, the linear GW theory predicts that GW can propagate freely in the dead wind. The vertical wavelength simulated by the nonlinear numerical model is different from that predicted by the linear theory greatly after GW propagates into the dead wind.

关键词： gravity waves background winds vertical group velocity vertical wavelength nonlinear interactions.

An oblivious fragile watermarking scheme for images utilizing edge transitions in BTC bitmaps

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Science china(Information Sciences) 2012年第11期55卷 2570-2581页

作者： ZHANG Yong1,LU ZheMing2.& ZHAO DongNing1 1ATR National Defense Technology Key Laboratory,College of Information Engineering,shenzhen university,shenzhen 518060,china 2.chool of Aeronautics and Astronautics,Zhejiang university,Hangzhou 31002.,china 1. ATR National Defense Technology Key Laboratory College of Information Engineering Shenzhen University Shenzhen 518060 China2. School of Aeronautics and Astronautics Zhejiang University Hangzhou 310027 China

As one of the famous block-based image coding schemes,block truncation coding(BTC) has been also applied in digital *** BTC-based watermarking or hiding schemes usually embed secret data by modifying the BTC encoding stage or BTC-compressed data,obtaining the watermarked image with poorer quality than the BTC-compressed *** paper presents a new oblivious image watermarking scheme by exploiting BTC *** the traditional schemes,our approach does not really perform the BTC compression on images during the embedding process but utilizes the parity of the number of horizontal edge transitions in each BTC bitmap to guide the watermark embedding and extraction *** embedding process starts by partitioning the original cover image into non-overlapping 4×4 blocks and performing BTC on each block to obtain its BTC *** watermark bit is embedded in each block by modifying at most three pixel values in the block to make sure that the parity of the number of horizontal edge transitions in the bitmap of the modified block is equal to the embedded watermark *** the extraction stage,the suspicious image is first partitioned into non-overlapping 4×4 blocks and BTC is performed on each block to obtain its ***,by checking the parity of the number of horizontal edge transitions in the bitmap,we can extract one watermark bit in each *** results demonstrate that the proposed watermarking scheme is fragile to various image processing operations while keeping the transparency very well.

关键词： fragile image watermarking oblivious watermarking block truncation coding data hiding image authentication