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A model-based prognostics method for fatigue crack growth in fuselage panels

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Chinese Journal of Aeronautics 2019年第2期32卷 396-408页

作者： yiwei WANG Christian GOGU Nicolas BINAUD Christian BES Jian FU School of Mechanical Engineering and Automation Beihang University Institut Clément Ader (UMR CNRS 5312) INSA/UPS/ISAE/Mines Albi Université de Toulouse

This paper proposes a model-based prognostics method that couples the Extended Kalman Filter(EKF) and a new developed linearization method. The proposed prognostics method is developed in the context of fatigue crack propagation in fuselage panels where the model parameters are unknown and the crack propagation is affected by different types of uncertainties. The coupled method is composed of two steps. The first step employs EKF to estimate the unknown model parameters and the current damage state. In the second step, the proposed efficient linearization method is applied to compute analytically the statistical distribution of the damage evolution path in some future time. A numerical case study is implemented to evaluate the performance of the proposed method. The results show that the coupled EKF-linearization method provides satisfactory results: the EKF algorithm well identifies the model parameters, and the linearization method gives comparable prediction results to Monte Carlo(MC) method while leading to very significant computational cost saving. The proposed prognostics method for fatigue crack growth can be used for developing predictive maintenance strategy for an aircraft fleet, in which case, the computational cost saving is significantly meaningful.

关键词： Aircraft fuselage panels Extended Kalman filter Fatigue crack propagation Linearization method Model-based prognostics

Authenticating QoS-Guaranteed Multicast Route Discovery for Ad hoc Networks

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China Communications 2007年第1期4卷 48-55页

作者： Mingxi, Yang Layuan, Li yiwei, Fang Wuhan Univ Technol Sch Comp Sci & Tech Wuhan 430070 Peoples R China Huazhong Univ Sci & Technol Dept Elect & Inf Eng Wuhan 430074 Peoples R China

This paper presents SEQMRAN,a novel secure efficient QoS multicast route discovery protocol for mobile ad hoc *** protocol relies entirely on one-time signature mechanism,HORSEI,with very efficient signing and verifying,and we do this by improving the HORSE protocol through the introduction of intermediate hash *** main purpose of SEQMRAN is to provide source authentication for QoS multicast routing discovery messages in MANET by constructing multicast tree with QoS and authentication constrains in mobile ad hoc *** performance measure of SEQMRAN is evaluated using network simulator *** results represent that SEQMRAN produces less end-to -end packet latency than RSA public key encryption based secure routing scheme,and it is a feasible approach to securing multicast routing with multiple QoS constrains for mobile ad hoc networks.

关键词： ad hoc maodv QoS security route

Porous polymer microsphere functionalized with benzimidazolium based ionic liquids as effective solid catalysts for esterification

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Chinese Journal of Chemical Engineering 2019年第10期27卷 2455-2466页

作者： Xiaomei Ling yiwei Xie Xiaocheng Lin Ling Li Ting Qiu School of Chemical Engineering Fuzhou UniversityFuzhou 350116FujianChina

To prepare polymer supported ionic liquids(PSILs)as effective catalysts for esterification,the free radical suspension copolymerization of vinylbenzyl chloride(VBC,monomer),styrene(St,monomer)and divinylbenzene(DVB,crosslinker)with the addition of n-heptane(porogen)was carried out for the fabrication of the porous polymer(PVD)microsphere as support,followed by the immobilization of sulfonic acid-functionalized ionic liquids by the successive treatment of benzimidazole(BIm),1,3-propane sultone and sulfuric acid(H2SO4)or trifluoromethanesulfonic acid(CF3SO3H).The effects of the compositions of DVB and n-heptane on the internal structure of the polymer supports were investigated,and it was found that the support with 40 wt%DVB and 60 wt%n-heptane(with relative to the monomer)could endow the final PSILs with the relatively optimal catalytic *** preliminary experiment in the batch reactor indicated that PSILs herein exhibited higher catalytic activities than commercial Amberlyst 46 resin for the esterification of propanoic acid(PROAc)with n-propanol(PROOH).Consequently,the optimal PSILs catalyst,PVD-[Bim-SO3H]HSO4,was selected for further study in the batch reactive distillation column because of low cost and its ease of *** yield of propyl ropionate(PROPRO)could reach up to 97.78%at the optimized conditions of PROOH/PROAc molar ratio(2:1)and catalyst dosage(2.0 wt%).The investigation of the reaction kinetic manifested that the calculated results of second order pseudo-homogeneous kinetic model were in good agreement with experimental *** pre-exponential factor and activation energy were 4.12×107 L·mol-1·min-1 and 60.57 k J·mol-1,*** is worth noting that the PSILs catalyst could be simply recovered and reused with relatively satisfactory decrease in the catalytic activity,which made it an environmental friendly and promising catalyst in the industrial application.

关键词： Supported ionic liquids Porous polymer microsphere Copolymerization Esterification Reactive distillation

Histone mimics： digging down under

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Frontiers in Biology 2013年第2期8卷 228-233页

作者： yiwei LIN Binhua R ZHOU Departments of Molecular and Cellular Biochemistry and Markey Cancer Center College of Medicine The University of KentuckyLexington KY 40506 USA

Epigenetic deregulation is intimately associated with the development of human diseases. Intensive studies are currently underway to clarify the mechanism for the sake of achieving ideal diagnostic and therapeutic goals. It has been demonstrated that enzymes with histone-modifying activities can also target non-histone proteins, with the underlying mechanism remaining obscure. In this review, we focus on a novel histone mimicry strategy that may be wildly adapted during the non-histone substrate recognition process. Its potential clinical implications are also discussed.

关键词： epigenetics histone mimicry

Construction of a novel ZnCo_2O_4/Bi_2O_3 heterojunction photocatalyst with enhanced visible light photocatalytic activity

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Chinese Chemical Letters 2019年第3期30卷 735-738页

作者： Jun Chen Jing Zhan Yumeng Zhang yiwei Tang School of Metallurgy and Environment Central South University Guangdong Jiana Energy Technology Co. Ltd.

A novel ZnCo_2O_4/Bi_2O_3 heterojunction photocatalyst was prepared, and the formation of the heterojunction was confirmed via HRTEM. Photocatalytic activity of as-prepared samples was evaluated through photodegradation of malachite green(MG). The degradation results show that the as-prepared13% ZnCo_2O_4/Bi_2O_3 heterojunction photocatalyst exhibits higher activity than pure Bi_2O_3. The MG degradation rate for the as-prepared catalyst is as high as 94%. The enhanced photocatalytic activity is mainly attributed to the broad photoabsorption and low recombination rate of photogenerated electronhole pairs, which is driven by the photogene rated potential difference formed at the ZnCo_2O_4/Bi_2O_3 heterojunction interface.

关键词： ZnCo2O4/Bi2O3 Photocatalyst Heterojunction Semiconductors Degradation

Recent advances in acid-resistant zeolite T membranes for dehydration of organics

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Chinese Journal of Chemical Engineering 2019年第6期27卷 1449-1457页

作者： yiwei Luo Waseem Raza Jianhua Yang Liangqing Li Ying Lu State Key Laboratory of Fine Chemicals School of Chemical EngineeringDalian University of TechnologyDalian 116024China Collaborative Innovation Center of Fine Chemical and Materials Technology School of Chemistry and Chemical EngineeringHuangshan UniversityHuangshan 245041China

Zeolite membranes offer outstanding potentials in separation of many molecular mixtures due to their molecular sieving selectivity and the high thermal and mechanical stability that allow them to operate at harsh *** of durable and high separation performance membranes with lower fabrication and operation cost are highly demanded for industrial applications. Zeolite T membrane possesses good acid-resistance with excellent hydrophilic properties as compared to NaA zeolite membrane and can be extended to industrial organic dehydrations under an acidic environment. In the present review the research advances in development of zeolite T membranes for the dehydration of organic mixtures in acidic conditions are summarized. Especially the low temperature synthesis, and epitaxial growth of the zeolite membrane with high performance are well addressed, besides emphasis is particularly placed on ensemble synthesis of hollow fiber zeolite T membrane module and its future prospects for industrial separations.

关键词： Dehydration of organics Epitaxial growth Zeolite T membrane Membrane pervaporation

Advances in Multiplexed Microfluidics for Infectious Disease Detection

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Infectious Microbes & Diseases 2023年第2期5卷 56-63页

作者： yiwei Shi Jiayi Zhao Guangwen Cao Department of Epidemiology Second Military Medical UniversityShanghaiChina Shanghai Key Laboratory of Medical Bioprotection ShanghaiChina Key Laboratory of Biological Defense Ministry of EducationShanghaiChina.

Microfluidics enables miniaturization,functionality,high throughput and reproducibility of multipathogen *** microfluidic devices are electrochemical sensor–based,optical sensor–based,immunosensor-based and paper-based multiplexed ***,the simultaneous detection ofmultiple pathogens is limited because of the complexity and diversity of infectious disease sources and mutual interference among *** review provides an overview of recent advances in developing multiplex diagnostic microfluidic devices for detecting infectious diseases and discusses practical issues and *** review also coversmicrofluidic nucleic acid amplification strategies to improve detection ***,we discuss the limitations and challenges in the design of multiplexed microfluidics.

关键词： microfluidics simultaneous detection infectious diseases

Preparation and Properties of a Long-life Cementbased Mortar Used on Metal Oilcans

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Journal of Wuhan University of Technology(Materials Science) 2014年第2期29卷 309-313页

作者：孙世安 FEI yiwei YANG Hongwei XIAO Yunpeng 宗志敏 Key Laboratory of Coal Processing and Efficient Utilization China University of Mining and Technology Department of Aviation Oil and Materials Air Force Logistics College

Organic-based materials are often used as the coating of metal oilcans. But they need to be sprayed several times in the whole life of oilcans because of the short-life of organic components. To overcome this problem, a type of long-life flexible cement-based anti-corrosion material used on the surface of metal oilcans was developed according to the principle that the steel reinforced concrete can remain the same life with buildings. The materials with different formulas composed of acrylic ~nulsion, cement and other additives were prepared. Because the ratios of polymer to cement played the decisive role in the adhesion and anti-corrosion characteristics, their effects on the physical performances were investigated by comparing the mechanical properties, anti-corrosion and anti-aging properties. The relationship between microstructure and macroscopic properties was also discussed.

关键词： mental oilcan long-life anti-corrosion material coment-based mortar

Degree of coupling and coordination of eco-economic system and the influencing factors： a case study in Yanchi County, Ningxia Hui Autonomous Region, China

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Journal of Arid Land 2017年第3期9卷 446-457页

作者： LU Huiling ZHOU Lihua CHEN Yong AN yiwei HOU Caixia Key Laboratory of Desert and Desertification Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou 730000 China Institutes of Science and Development Chinese Academy of Sciences Beijing 100190 China

Based on the statistical data, we analyzed and evaluated the degree of coupling and coordination of the eco-economic system in Yanchi County for the period spanning from 1983 to 2014. The eco-economic system can be divided into socioeconomic and ecological sub-systems and their relationship can reveal the interaction state between the two sub-systems and help the local government to establish a coordinated development mode. An index system was constructed to assess the development of the two sub-systems before the evaluation of the degree of coupling and coordination. The principal component regression analysis was adopted to quantitatively assess the influences of natural, economic and social factors on the degree of coupling and coordination of the eco-economic system. Results showed that, from 1983 to 2014, the development trends of both sub-systems were increasing with the ecological sub-system having more fluctuations. The degree of coupling and coordination of the eco-economic system in the study area increased gradually from 1983 to 2014, but experienced five different development stages from the verge of disorder to favorable coordination. The development of the local social and economic conditions was the most important factor influencing the degree of coupling and coordination. The second most important factor was the financial support from the local government. In addition, the environment protection policies also played undeniable roles. Due to the diversity of the influence factors, the government should take comprehensive measures to promote the sustainable development of the eco-economic system.

关键词： degree of coupling and coordination eco-economic system ecological sub-system socioeconomic sub-system YanchiCounty