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Coking of Pt/γ-Al_(2)O_(3) catalyst in landfill gas deoxygen and its effects on catalytic performance

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Chinese Journal of Chemical Engineering 2023年第5期57卷 224-232页

作者： xinyu yang Zezhi Chen Huijuan Gong State Key Laboratory of Pollution Control and Resource Reuse School of EnvironmentNanjing UniversityNanjing 210023China Center of Materials Analysis Nanjing UniversityNanjing 210093China

Catalytic oxidation of CH_(4) has been proved to be an attractive option for landfill gas(LFG) ***, coking of catalysts in catalytic LFG deoxygen has been clearly observed in industrial applications. In this regard, it is necessary to investigate whether coke deposition originates from CH_(4) or volatile organic compounds present in LFG, and the influence of coke deposition on catalytic performance. Herein,we evaluate the LFG deoxygen on Pt/γ-Al_(2)O_(3) catalyst in simulated LFG(CH_(4), CO_(2), O_(2), N_(2)) and its co-feed with representative volatile organic compounds, ethylbenzene, toluene, benzene and cyclohexane. The results show that the coking of the catalyst is originated from volatile organic compounds rather than CH_(4). The Pt/γ-Al_(2)O_(3) catalyst does not deactivate during LFG deoxygen process, even significant amount of coke deposited, up to 18.15%(mass). Characterization analyses reveal that although coke deposition overall covers the catalyst surface, resulting in mesopores blockage and a reduced number of accessible Pt sites, however, the coke formed, H-rich carbonaceous components, behaves as counterpart for O_(2) elimination. Besides, the coke deposited is mainly filamentous. Thus, coke formation has little negative effect on the overall catalytic performance of Pt/γ-Al_(2)O_(3) catalyst ultimately. The results obtained in this work are helpful for the rational design of robust Pt based catalysts for LFG deoxygen without undue attention to their coking properties, and also favor the innovation of more attractive purification scheme configurations.

关键词： Landfill gas Deoxygen Pt/γ-Al_(2)O_(3) Volatile organic compounds Coke deposition

Joint Optimization of Admission Control and Rate Adaptation for Video Sharing over Multirate Wireless Community Cloud

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China Communications 2016年第8期13卷 24-40页

作者： Peng Zhao xinyu yang Department of Computer Science and Technology Xi'an Jiaotong University

Emerging wireless community cloud enables usergenerated video content to be shared and consumed in a social context. However, the nature of shared wireless medium and timevarying channels seriously limits the quality of service(QoS), partially owing to the lack of mechanisms for effectively utilizing multi-rate channel resources. In this paper, the joint optimization of admission control and rate adaptation is proposed, resulting in a bandwidth-aware rate-adaptive admission control(BRAC) scheme to provide bandwidth guarantee for sharing social multimedia contents. The analytical approach leads to the following major contributions:(1) a bandwidth-aware rate selection(BRS) algorithm to optimally meet the bandwidth requirement of the data session and channel conditions at the physical layer;(2) a routing-coupled rate adaption and admission control algorithm to admit data sessions with bandwidth guarantee. Moreover, extensive numerical simulations suggest that BRAC is efficient and effective in meeting the bandwidth requirements for sharing social multimedia contents. These insights will shed light on communication system implementation for multimedia content sharing over multirate wireless community cloud.

关键词： wireless community cloud multirate rate adaptation bandwidth guarantee admission control

Hierarchical interacting multiple model algorithm based on improved current model

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Journal of Systems Engineering and Electronics 2010年第6期21卷 961-967页

作者： Xianghua Wang xinyu yang Zheng Qin Huijie yang Department of Computer Science and Technology Tsinghua University Beijing 100084 R R. China Department of Computer Science and Technology Xi'an Jiaotong University Xi'an 710049 P. R. China

Interacting multiple models is the hotspot in the research of maneuvering target models at present. A hierarchical idea is introduced into IMM algorithm. The method is that the whole models are organized as two levels to co-work, and each cell model is an improved ＂current＂ statistical model. In the improved model, a kind of nonlinear fuzzy membership function is presented to get over the limitation of original model, which can not track weak maneuvering target precisely. At last, simulation experiments prove the efficient of the novel algorithm compared to interacting multiple model and hierarchical interacting multiple model based original ＂current＂ statistical model in tracking precision.

关键词： target tracking "current" statistical model multiple model hierarchical.

Urban Agglomeration Formation and Its Spatiotemporal Expansion Process in China: From the Perspective of Industrial Evolution

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Chinese Geographical Science 2020年第3期30卷 532-543页

作者： NIU Fangqu yang xinyu WANG Fang Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China Col-laborative Innovation Center for Geopolitical Setting of Southwest China and Borderland Development Kunming 650500China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China School of Public Administration Inner Mongolia UniversityHohhot 010070China

Urban agglomeration research has received increasing attention in China’s national development strategies, and has become a hot topic in academic research. This study develops a theoretical framework that explores the formation mechanism and expansion process of urban agglomerations from the perspective of industrial evolution, and identifies the development issues and their causes by taking yangtze Delta and Beijing-Tianjin-Hebei urban agglomerations as case studies. In the process of urban agglomeration formation within a free market, as has happened in yangtze Delta region, the central city develops first, its secondary industry is then transferred to its neighboring cities, and the work division and cooperation with the neighboring cities is gradually established. However, in the 1990 s, aiming to become an international metropolis, Beijing implemented a series of administrative policies to encourage the reduction of the secondary industry and the development of the tertiary industry, before its secondary industry were fully developed and transferred to its neighboring cities. This delayed the integration process and the development of the Beijing-Tianjin-Hebei urban agglomeration. This study builds a good foundation for the construction of the theoretical system’s urban agglomeration study, and provides references for decision making in an urban agglomeration development.

关键词： urban agglomeration expansion mechanism industry Beijing-Tianjin-Hebei yangtze Delta

“数字中国”背景下学前教育数字化资源建设现状与对策研究

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四川师范大学学报（自然科学版） 2025年第2期48卷 208-219页

作者：胡晓瞿畅杨欣雨四川师范大学巴蜀研究院四川成都610066 四川师范大学影视与传媒学院四川成都610066

中国学前教育数字化资源丰富,但是存在区域差异,国家和省级优质学前教育资源整合效率不能满足现有的数字化资源需求,学前教育数字化资源利用质量不高.调研现有学前数字化资源平台,对资源建设部门工作人员、幼儿园管理者和教师进行访谈,... 详细信息

中国学前教育数字化资源丰富,但是存在区域差异,国家和省级优质学前教育资源整合效率不能满足现有的数字化资源需求,学前教育数字化资源利用质量不高.调研现有学前数字化资源平台,对资源建设部门工作人员、幼儿园管理者和教师进行访谈,发现中国省级以上教育部门学前教育数字化共享资源严重匮乏,企业提供的学前数字化资源缺乏资源建设标准和监管机制,资源质量参差不齐.基于学前数字化资源建设不完善的情况,提出学前教育大数据资源检索、可视化和聚合策略模型,以及学前数字化资源评价策略,为学前教育数字化资源建设单位和幼儿园提供数字化资源建设参考.

关键词：学前教育数字化资源建设教师数字素养资源聚合

SAR performance-based fault diagnosis for electrohydraulic control system:A novel FDI framework for closed-loop system

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Chinese Journal of Aeronautics 2022年第10期35卷 381-392页

作者： yang ZHANG Shaoping WANG Jian SHI xinyu yang Jiarui ZHANG Xi WANG School of Energy and Power Engineering Beihang UniversityBeijing 100191China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Institute for Automatic Control and Complex Systems(AKS) University of Duisburg-EssenDuisburg 47057Germany

Model-based fault diagnosis serves as an efficient and powerful technique in addressing fault detection and isolation(FDI)issues for control ***,the standard methods and their modifications still encounter some difficulties in algorithm design and application for complex higher-order *** avoid these difficulties,a novel fault diagnosis framework based on multiple performance indicators of closed-loop control system is *** this framework,a socalled performance residual vector is constructed to measure the differences between the real system and the nominal model in terms of system stability,accuracy,and rapidity(SAR)*** criteria for quantification,normalization of the SAR residuals and the explicit mappings between the thresholds and the required performance are *** can be easily achieved simultaneously by monitoring the normalized residual vector length and direction in the SAR performance residual space.A case study on electro-hydraulic servo control system of turbofan engine is adopted to demonstrate the effectiveness of the proposed method.

关键词： Electro-hydraulic servo valve(EHSV) Fault diagnosis Fuel metering unit Performance degradation Performance residual Stability,accuracy,and rapidity(SAR)

A review on thermal conductivity of magnesium and its alloys

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Journal of Magnesium and Alloys 2020年第1期8卷 78-90页

作者： Shubo Li xinyu yang Jiangtao Hou Wenbo Du College of Materials Science and Engineering Beijing University of TechnologyBeijing 100124P.R.China

This review summarizes recent researching works the thermal conductivity of Mg–Zn,Mg–Al,Mg–Mn and Mg–RE *** atoms,heat treatment,deformation and temperature,which have significant influence on the thermal conductivity of magnesium alloys,are *** an individual solute atom,its effects on thermal conductivity are highly dependent on its chemical valence,radius and extra-nuclear *** thermal conductivity of Mg alloys is decreased by solution treatment,but improved by aging and/or annealing *** for the deformed Mg alloys,the thermal conductivity along transverse or normal direction is superior to that of along extrusion or rolling *** expect this review is helpful for those who are working on developing Mg alloys with superior thermal conductivity.©2020 Published by Elsevier *** behalf of Chongqing University.

关键词： Magnesium alloys Thermal conductivity Microstructure Influencing factors

Synthesis and Flocculation of Polyacrylamide with Low Water Absorption for Non-dispersible Underwater Concrete

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Journal of Wuhan University of Technology(Materials Science) 2023年第6期38卷 1404-1413页

作者： LI Hongling YAN Na SUN Guowen ZHENG Haorui yang xinyu Depantment of Chemistry and Miaterials Engineering Xinxiang Normal CollegeXinxiang 453003China School of Materials Science and Engineering Shijiazhuang Tiedao UniversityShijiazhuang 050043China Hebei Key Laboratory of Advanced Materials for Transportation Engineering and Environment Shijiazhuang 050043China

The polyacrylamide which is directly added into concrete shows strong water absorption *** the construction of underwater constructure would demand high amount of water,resulting in poor workability of concrete and strength shrinkage after ***,a kind of anionic polyacrylamide(APAM)grafted with water reducing functional group(-COOH)was synthesized at low temperatures by partial factor design and response surface *** structure and morphology of APAM were characterized by UV,FTIR and SEM *** experimental results show that the molecular weight of the synthesized APAM could reach 11 million,under the condition that the temperature was 35℃,the pH value was 8,the monomer concentration was 27wt%,the initiator dosage was 0.6wt%,and the monomer ratio(n(AM):n(AA))was *** the APAM was applied into the underwater slurry,it presented good flocculation and low water *** the dosage was 1%of the mass of the cement,the water demand increased by 12%,which could meet the self-leveling and anti-dispersity of the underwater slurry at the same *** technology provides technical guidance for the large-scale industrial production of polyacrylamide for underwater concrete construction while achieving environmental protection during production.

关键词： non-dispersible underwater concrete anionic polyacrylamide partial factor design response surfacedesign flocculation

Detection and location algorithm against local-worm

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Science in China(Series F) 2008年第12期51卷 1935-1946页

作者： yang xinyu SHI Yi ZHU Huidun Department of Computer Science and Technology Xi'an Jiaotong University Xi'an 710049 China

The spread of the worm causes great harm to the computer network. It has recently become the focus of the network security research. This paper presents a local-worm detection algorithm by analyzing the characteristics of traffic generated by the TCP-based worm. Moreover, we adjust the worm location algorithm, aiming at the differences between the high-speed and the low-speed worm scanning methods. This adjustment can make the location algorithm detect and locate the worm based on different scanning rate. Finally, we verified the validity and efficiency of the proposed algorithm by simulating it under NS-2.

关键词： worm detection traffic characteristic detection and location