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Acta Mechanica Sinica 2014年第3期30卷 418-429页

作者： Zhen wang Qin Sun School of Aeronautics Northwestern Polytechnical University

A new 4-node quadrilateral flat shell element is developed for geometrically nonlinear analyses of thin and moderately thick laminated shell structures. The fiat shell element is constructed by combining a quadrilateral area co- ordinate method （QAC） based membrane element AgQ6- II, and a Timoshenko beam function （TBF） method based shear deformable plate bending element ARS-Q12. In order to model folded plates and connect with beam elements, the drilling stiffness is added to the element stiffness matrix based on the mixed variational principle. The transverse shear rigidity matrix, based on the first-order shear deformation theory （FSDT）, for the laminated composite plate is evaluated using the transverse equilibrium conditions, while the shear correction factors are not needed. The conventional TBF methods are also modified to efficiently calculate the element stiffness for laminate. The new shell element is extended to large deflection and post-buckling analyses of isotropic and laminated composite shells based on the element independent corotational formulation. Numerical re- sults show that the present shell element has an excellent numerical performance for the test examples, and is applicable to stiffened plates.

关键词： geometrically nonlinear. Quadrilateral area co-ordinate method Timoshenko beam function Laminatedcomposite Drilling degree of freedom ~ Corotational for-mulation

Study on the Lowest Navigable Water Level

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四川大学学报（工程科学版） 2005年第S1期37卷 118-123页

作者： wang, Xiuying Li, yitian Lab. of Water Resources and Hydropower Eng. Sci. Wuhan 430072 China

The design lowest navigable water level is a primary index to the channel grade *** differ- ent method can get different calculated result,and that even brings contradiction to decide the navigation *** this paper the differences between guaranteed rate method and guaranteed rate-frequency method on the fundamental concept of guaranteed rate and the calculated result are carried *** to the theoreti- cal expression forms of the two methods,the reason leading to the difference is an...

关键词： design water level design lowest navigable water level guaranteed rate method guaranteed ratefrequency method

Research on Network Malicious Code Immune Based on Imbalanced Support Vector Machines

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Chinese Journal of Electronics 2015年第1期24卷 181-186页

作者： LI Peng wang Ruchuan College of Computer Nanjing University of Posts and Telecommunications Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks

The malicious computer code immune system and the biological immune system are highly similar:both preserve the stability of the system in real time in a constantly changing environment. This similarity is exploited to design a malicious code immune system to solve the malware active defense problem. The malicious code immunization project is mainly composed of four major components: the immune information collection program,immune information filtering processing program, immunization information discrimination program, and immune response program. An imbalanced support vector machine method was applied to optimize output results of malicious code immunization, thereby removing uncertain malicious code immune outputs. This demonstrates in detail the feasibility of the imbalanced support vector machine method in optimizing the immunization program output data. We showed that an imbalanced support vector machines can optimize the outputs of the malicious code immune system by removing glitches from the outputs. As a result,the machine helps to determine the precise time of the emergence of the immune response.

关键词： Network malicious code immune Imbalanced support vector machines Computer network security Artificial intelligence Immunity theory.

Recent advances in high-performance triboelectric nanogenerators

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Nano Research 2023年第9期16卷 11698-11717页

作者： Di Liu yikui gao Linglin Zhou Jie wang Zhong Lin wang Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijing 101400China College of Nanoscience and Technology University of Chinese Academy of SciencesBeijing 100049China School of Materials Science and Engineering Georgia Institute of TechnologyAtlantaGA 30332USA

The development of the Internet of Things(IoT)and artificial intelligence has accompanied the evolution of energy demand and structure in the new era,and the power sources for billions of distributed electronics and sensors have aroused worldwide *** an alternative energy harvesting technology,triboelectric nanogenerators(TENgs)have received remarkable attention and have shown attractive potential applications for use in micro/nano power sources,self-powered sensors,highvoltage power sources,and blue energy due to their advantages of small size,light weight,flexibility,low cost,and high efficiency at low *** this review,we discuss high-performance TENgs from the perspectives of triboelectric charge density,output voltage,energy density,and corresponding quantification *** these topics,the limitations,optimization methods and techniques,and potential directions to challenge these limits are comprehensively discussed and ***,we discuss the emerging challenges,strategies,and opportunities for research and development of highperformance TENgs.

关键词： high-performance triboelectric nanogenerator(TENg) charge density voltage energy density average power density

Assembly of versatile fluorine-containing structures via N-heterocyclic carbene organocatalysis

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Science China Chemistry 2022年第9期65卷 1691-1703页

作者： Bei Zhang Jian wang School of Pharmaceutical Sciences Tsinghua UniversityBeijing 100084China College of Chemistry and Materials Science Anhui Normal UniversityWuhu 241000China

Owing to the unique properties of fluorine-containing moieties in the pharmaceuticals,agrochemicals and materials,several synthetic efforts(i.e.,enzymatic resolution,transition-metal catalysis,and organocatalysis)have been frequently made to fabricate these fluorinated *** powerful organic catalysts,N-heterocyclic carbenes can activate carbonyl group and realize the chiral intervention of multiple sites near the carbonyl group,and have an irreplaceable power to construct fluorine-containing ***,NHC-related reviews focused on the versatile synthesis of fluorine-containing fragments are absolutely rare to this *** mini-review highlights the invention of inserting fluorine atom or assembling fluorine-containing fragments via NHC *** summarizing the achievements in this field,we are eager to provide enlightening clues for further developments.

关键词： N-heterocyclic carbene fluorination electrophilic trifluoromethylation radical perfluoroalkylation annulation

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A brief review on Majorana bound states in topological superconductors

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Science China(Physics,Mechanics & Astronomy) 2016年第7期59卷 1-8页

作者： Rui Lin Zhi wang School of Physics and Engineering Sun Yat-sen University

Topological superconductivity has drawn much attention recently, and most interests are focused on the Majorana bound states existing at the edges of one-dimensional topological superconductors. These Majorana bound states are ideal platform for studying non-Abelian statistics. Meanwhile, they are proposed to be useful in quantum computation. In this review, we introduce the basic concepts and models in this area. We begin from the Kitaev model, which is the most concise model for one-dimensional topological superconductivity. Then, we discuss how to realize this model with spin-orbit coupling in realistic materials. Finally, we show some simple methods to detect the Majorana bound states and study their novel properties with the help of adjacent quantum dots.

关键词： topological superconductor Kitaev model quantum dot

An Icy Worlds life detection strategy based on Exo-AUV

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Science China Earth Sciences 2024年第11期67卷 3515-3535页

作者： Bin wang Hongde QIN National Key Laboratory of Autonomous Marine Vehicle Technology Harbin Engineering UniversityHarbin 150001China Shipbuilding Engineering College Harbin Engineering UniversityHarbin 150001China

In the solar system, Icy Worlds such as Europa and Enceladus hold great potential for extraterrestrial life and may provide humanity an answer, within this century, to the age-old question of life beyond Earth. Exo-AUV technology shows promise in life detection in the icy shell, at the ice-water interface and on the seafloor of exo-ocean. Space agencies, including NASA and DLR, are enthusiastic about deploying Exo-AUVs to explore life in these regions. However, the where and how to find life, the technologies to be utilized and the goals to be achieved are crucial aspects for future Exo-AUV life detection missions on Icy Worlds. This study delves into a hypothetical mission of life detection on Europa, discussing science goals,detectable objects, potential regions and biogenic analysis for Icy Worlds. It proposes a life detection strategy for Icy Worlds based on Exo-AUVs, presents key contextual elements for Exo-AUV operations, outlines technological requirements for hull,payloads and autonomy, introduces the current state of Exo-AUV research and addresses existing challenges. This study also suggests a roadmap for conceptual development of Exo-AUV and a Concept of Operations for Multiple Exo-AUV System(ConOps for MEAS). This system aims to assist planetary scientists and astrobiologists in exploring Icy Worlds, identifying robust biosignatures and potentially discovering extant organisms, even prebiotic chemical systems.

关键词： Icy Worlds Europa Life detection Biological potential Exo-AUV

Modelling envelope and temporal fine structure components of frequency-following responses in rat inferior colliculus

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Science China(Technological Sciences) 2017年第7期60卷 966-973页

作者： wang Qian LI Liang School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health Peking UniversityBeijing 100871China Beijing Key Laboratory of Epilepsy Epilepsy Center Department ofFunetional NeurosurgerySanbo Brain HospitalCapital Medical UniversityBeijing 100093China Speech and Hearing Research Center Key Laboratory on Machine Perception(Ministry of Education)Peking UniversityBeijing 100871China Beijing Institute for Brain Disorders Beijing 100081China

In studies of auditory perception, a dichotomy between envelope and temporal fine structure(TFS) has been emphasized. It has been shown that frequency-following responses(FFRs) in the rat inferior colliculus can be divided into the envelope component(FFREnv)and the temporal fine structure component(FFRTFS). However, the existing FFR models cannot successfully separate FFREnv and FFRTFS. This study was to develop a new FFR model to effectively distinguish FFREnv from FFRTFS by both combining the advantages of the two existing FFR models and simultaneously adding cellular properties of inferior colliculus neurons. To evaluate the validity of the present model, correlations between simulated FFRs and experimental data from the rat inferior colliculus were calculated. Different model parameters were tested, FFRs were calculated, and the parameters with highest prediction were chosen to establish an ideal FFR model. The results indicate that the new FFR model can provide reliable predictions for experimentally obtained FFREnv and FFRTFS.

关键词： frequency-following response envelope temporal fine structure inferior colliculus

Code constructions for multi-node exact repair in distributed storage

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Science China(Information Sciences) 2018年第10期61卷 80-97页

作者： Marwen ZORgUI Zhiying wang Center for Pervasive Communications and Computing(CPCC) Department of Electrical Engineering and Computer Science University of California at Irvine

We study the problem of centralized exact repair of multiple failures in distributed *** present constructions that achieve a new set of interior points under exact repair. The constructions build upon the layered code construction by Tian et al., designed for exact repair of single failure. We firstly improve upon the layered construction for general system parameters. Then, we extend the improved construction to support the repair of multiple failures, with varying number of helpers. In particular, for some parameters, we prove the optimality of one point in terms of the storage size and the repair bandwidth for multiple erasures. Finally, considering minimum bandwidth cooperative repair(MBCR) codes as centralized repair codes, we determine explicitly the best achievable region obtained by space-sharing among all known points, including the MBCR point.

关键词： regenerating codes exact repair multiple failures interior points Steiner systems

Large-scale video compression： recent advances and challenges

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Frontiers of Computer Science 2018年第5期12卷 825-839页

作者： Tao TIAN Hanli wang Department of Computer Science and Technology Tongji University Shanghai 201804 China Key Laboratory of Embedded System and Service Computing Ministry of Education Tongji University Shanghai 200092 China Shanghai Engineering Research Center of Industrial Vision Perception & Intelligent Computing Shanghai 200092 China

The evolution of social network and multimedia technologies encourage more and more people to generate and upload visual information, which leads to the generation of large-scale video data. Therefore, preeminent compression technologies are highly desired to facilitate the storage and transmission of these tremendous video data for a wide variety of applications. In this paper, a systematic review of the recent advances for large-scale video compression （LSVC） is presented. Specifically, fast video coding algorithms and effective models to improve video compression efficiency are introduced in detail, since coding complexity and compression efficiency are two important factors to evaluate video coding approaches. Finally, the challenges and fu- ture research trends for LSVC are discussed.

关键词： large-scale video compression fast video coding compression efficiency