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Specification and Verification of the Zab Protocol with TLA+

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Journal of Computer Science & Technology 2020年第6期35卷 1312-1323页

作者： jia-Qi Yin Hui-Biao Zhu yuan Fei Shanghai Key Laboratory of Trustworthy Computing East China Normal UniversityShanghai 200062China College of Information Mechanical and Electrical EngineeringShanghai Normal UniversityShanghai 200234China

ZooKeeper Atomic Broadcast (Zab) is an atomic broadcast protocol specially designed for ZooKeeper, which supports additional crash recovery. This protocol actually has been widely adopted by famous Internet companies, but there are few studies on the correctness and credibility of the Zab protocol, and thus we utilize formal methods to study the correctness. In this paper, Zab, Paxos and Raft are all analyzed and compared to help better understand the Zab protocol. Then we model the Zab protocol with TLA+ and verify three properties abstracted from the specification by the model checker TLC, including two liveness properties and one safety property. The final experimental results can prove that the design of the protocol conforms to the original requirements. This paper makes up for the analysis of formal methods in the Zab protocol.

关键词： Zab protocol TLA+ specification verification

Simultaneous anaerobic-aerobic biodegradation of halogenated phenolic compound under oxygen-limited conditions

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Journal of Environmental Sciences 2005年第5期17卷 873-875页

作者： CHEN yuan-cai LAN Hui-xia ZHAN huai-yu FU Shi-yu State Key Laboratory of Pulp and Paper Engineering South China University of Technology Guangzhou 510641 China Laboratory of Cellulose and Liguocellulosics Chemistry Chinese Academy of Sciences Guangzhou 510650 China

The successful application of co-immobilized aerobic-anaerobic biomass under limited aeration in wastewater treatment systems would eliminate the problems associated with the intermediates mono-chlorophenol（MCP） and di-chlorophenol（DCP） accumulations. With low initial pentachlorophenol（PCP） concentration, all PCP could be completely removed under oxygen-limited strict anaerobic conditions, and the removal efficiencies with different initial headspace oxygen percentage（IHOP） were not obviously different from each other. While at high initial PCP concentration, under strictly anaerobic conditions PCP and their intermediates were clearly higher than that under other conditions, and produced obvious accumulation, the highest PCP reduction was achieved by the system receiving 30 IHOP, oxygen-limited system also exhibited lower residual TOC concentration and lower concentration of metabolic intermediates MCP and DCP. These results suggested that under strictly anaerobic condition the reductive dechlorination of low chlorinated compounds became rate limiting in the reductive dechlorination pathway, less chlorinated compounds be more amenable to aerobic degradation, and the aerobes of outer layers could function under limited oxygen. The co-immobilized aerobic-anaerobic biomass for methanogenesis under limited-aeration for chlorophenol degradation might be an attractive and efficient alternative for the sequential anaerobic/aerobic system to achieve mineralization of a broad range of recalcitrance highly chlorinated organics and low final TOC concentrations.

关键词： PCP oxygen-limited immobilized cellr

Quasiparticle scattering interference in electron-doped cuprate superconductors

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Frontiers of physics 2015年第6期10卷 109-116页

作者： Shu-Hua Wang Shuang-Sheng Yang huai-Song Zhao Feng yuan College of Physics Qingdao University Qingdao 266071 China

By considering the nonmonotonic d-wave gap effect, the energy and momentum dependence of quasiparticle scattering interference is studied in the presence of a single impurity. It is shown that the pattern of the quasiparticle scattering peaks in the full Brillouin zone of electron-doped cuprate superconductors is very different from that in the hole-doped case described by the Octet model. This difference is the result of the nonmonotonic d-wave superconducting gap in the electron-doped case. As the energy increases, the position of the local peaks in the Brillouin zone moves rapidly. In particular, the characteristic peaks of the electron-doped cuprate superconductors appear between the antinodal and nodal directions, unlike in the hole-doped case.

关键词： cuprate superconductors

High-temperature phase relations of ZrN–ZrO_2–Y_2O_3 ternary system

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Journal of Advanced Ceramics 2018年第4期7卷 388-391页

作者： Youjun LU Zhenxia yuan Hongfang SHEN Xiaochen huai Zhenkun HUANG School of Materials Science and Engineering North Minzu University School of Materials Science and Engineering Tsinghua University

Zirconium nitride(ZrN) ceramics were prepared via hot pressed sintering(HP) at 1750 ℃ in N_2 atmosphere with ZrO_2–Y_2O_3 as sintering additive. X-ray diffraction was applied to analyze the phase composition of the as-prepared ceramics to study the high temperature phase relation in ZrN –ZrO_2–Y_2O_3 ternary system and establish ZrN –ZrO_2–Y_2O_3 ternary phase diagrams. The results show that ZrN and tetragonal ZrO_2(t-ZrO_2) solid solution, face-centered cubic ZrO_2(c-ZrO_2) solid solution, body-centered cubic Y_2O_3(c-Y_2O_3) solid solution coexist in the system of ZrN –ZrO_2–Y_2O_3.

关键词： high temperature phase relations zirconium nitride (ZrN) ternary system X-ray diffraction

Microstructural and mechanical response of ZK60 magnesium alloy subjected to radial forging

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Journal of Materials Science & Technology 2021年第24期83卷 228-238页

作者： Jingfeng Zou Lifeng Ma Weitao jia Qichi Le Gaowu Qin yuan yuan Heavy Machinery Engineering Research Center Ministry of EducationTaiyuan University of Science and TechnologyTaiyuan030024China School of Mechanical Engineering Taiyuan University of Science and TechnologyTaiyuan030024China Key Laboratory of Electromagnetic Processing of Materials Ministry of EducationNortheastern UniversityShenyang110819China Key Laboratory for Anisotropy and Texture of Materials Ministry of EducationNortheastern UniversityShenyang110819China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing400044China

Radial forging(RF)is an economical manufacturing forging process,in which four dies arranged radially around the workpiece simultaneously act on the workpiece with high-frequency radial *** this study,a ZK60 magnesium alloy step-shaft bar was processed under different accumulated strains by RF at350℃.The deformation behavior,microstructure evolution,and mechanical responses of this bar were systematically investigated via numerical simulations and *** the early deformation stage of forging,the material undergoes pronounced grain refinement but an inhomogeneous grain structure is formed due to the strain gradient along the radial *** grains in different radial parts were gradually refined by increasing the RF pass,resulting in a bimodal grained structure comprising coarse(~14.1μm)and fine(~2.3μm)*** the RF pass increased,the initial micro-sizeβ-phases were gradually crushed and dissolved into the matrix mostly,eventually evolving to form a higher area fraction of nano-sized Zn2 Zr spheroidal particles uniformly distributed through the grain *** texture changed as the RF strain increased,with the c-axes of most of the deformed grains rotating in the ***,excellent mechanical properties including higher values of tensile strengths and ductility were attained after the three RFed passes,compared to the as-received sample.

关键词： ZK60 magnesium alloy Radial forging Microstructure Texture evolution Mechanical properties

Unique Solvability for a Class of Non-newtonian Fluids for a Reacting Mixture with Vacuum

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Acta Mathematicae Applicatae Sinica 2016年第4期32卷 833-850页

作者： Hong-jun yuan jia-ning XIE College of Mathematics Jilin University School of Mathematics and Quantitative Economics Dongbei University of Finance and Economics

In this paper,we consider a class of non-Newtonian fluids for a reacting mixture in one-dimensional bounded interval, provided the initial data satisfying a compatibility condition. The main ingredient is that we allo... 详细信息

关键词： existence and uniqueness reactive gas flow vacuum non-Newtonian

Entity generation algorithm based on reference expansion

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Journal of Electronic Science and Technology 2023年第3期21卷 63-72页

作者： jia-jia Ruan Xi-Xu He Min Zhang yuan Gao Office of Scientific Research&Development University of Electronic Science and Technology of ChinaChengdu611731China School of Resources and Environment University of Electronic Science and Technology of ChinaChengdu611731China Information Center University of Electronic Science and Technology of ChinaChengdu611731China Archives University of Electronic Science and Technology of ChinaChengdu611731China

The extraction and understanding of text knowledge become increasingly crucial in the age of big *** of the current research areas in the field of natural language processing(NLP)is how to accurately understand the text and collect accurate linguistic information because Chinese vocabulary is diverse and *** paper mainly studies the candidate entity generation module of the entity link *** candidate entity generation module constructs an entity reference expansion algorithm to improve the recall rate of candidate *** order to improve the efficiency of the connection algorithm of the entire system while ensuring the recall rate of candidate entities,we design a graph model filtering algorithm that fuses shallow semantic information to filter the list of candidate entities,and verify and analyze the efficiency of the algorithm through *** analyzing the related technology of the entity linking algorithm,we study the related technology of candidate entity generation and entity disambiguation,improve the traditional entity linking algorithm,and give an innovative and practical entity linking *** recall rate exceeds 82%,and the link accuracy rate exceeds 73%.Efficient and accurate entity linking can help machines to better understand text semantics,further promoting the development of NLP and improving the users’knowledge acquisition experience on the text.

关键词： Chinese Wikipedia Entity reference expansion Graph model

On Levine–O'Sullivan's Sequence and Its Conjecture

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Acta Mathematica Sinica,English Series 2016年第8期32卷 961-966页

作者： jia yuan HU Wen Peng ZHANG School of Mathematics Northwest University

Let ql = 1, and qn be the largest value of （k ＋ 1）（n - qk） for all integers 1 ≤ k≤ n - 1 with n ≥ 2. The sequence Q -- {q1, q2, q3,...} is called Levine-O＇Sullivan sequence. In this paper, we use the combinational and analysis skill and the mathematical induction to study the asymptotic properties of qn, and give an interesting asymptotic formula for it. This solved a conjecture proposed by Professor Chen Yonggao.

关键词： Levine-O'Sullivan sequence sum-free sequences estimate conjecture

Evaluating the Clogging Behavior of Pervious Concrete(PC)Using the Machine Learning Techniques

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Computer Modeling in Engineering & Sciences 2022年第2期130卷 805-821页

作者： jiandong Huang jia Zhang yuan Gao School of Mines China University of Mining and TechnologyXuzhou221116China School of Chemical Engineering and Technology China University of Mining and TechnologyXuzhou221116China

Pervious concrete(PC)is at risk of clogging due to the continuous blockage of sand into it during its service *** study aims to evaluate and predict such clogging behavior of PC using hybrid machine learning *** on the 84 groups of the dataset developed in the earlier study,the clogging behavior of the PC was determined by the algorithm combing the SVM(support vector machines)and particle swarm optimization(PSO)*** PSO algorithm was employed to adjust the hyperparameters of the SVM and verify the performance using 10-fold *** predicting results of the developed model were assessed by the coefficient of determination(R)and root mean square error(RMSE).The importance of the influential variables on the clogging behavior of PC was evaluated as *** results showed that the PSO algorithm can effectively adjust the hyperparameters of the SVM model and can be used to construct the predictive model for the clogging behavior of the *** combined algorithm has the advantage of higher reliability and validity than the random hyperparameters *** the verification process,the developed model was able to obtain values of 0.9469 and 1.8148 for the R and RMSE,showing that the developed machine learning model can accurately be used to evaluate and predict the clogging behavior of the PC,guiding the mix-design of PC from the perspective of *** size of the clogging sand is the most important parameter and the thickness of the sample is the least significant factor affecting the clogging *** proportions of the smallest aggregate size and largest aggregate size are the two most important design parameters of concrete with the consideration of the relatively higher importance scores,showing these two aggregates should be given special attention in future PC design for anti-clogging purposes.

关键词： Clogging behavior pervious concrete SVM PSO