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Parameter uncertainty modeling of safety instrumented systems

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Petroleum Science 2021年第6期18卷 1813-1828页

作者： bao-ping cai Wen-Chao Li Yong-Hong Liu Yan-ping Zhang Yi Zhao Xiang-Di Kong Zeng-Kai Liu Ren-Jie Ji Qiang Feng College of Mechanical and Electronic Engineering China University of PetroleumQingdao266580ShandongChina School of Reliability and Systems Engineering Beihang UniversityBeijing100191China

In this study,a novel safety integrity level(SIL)determination methodology of safety instrumented systems(SISs)with parameter uncertainty is proposed by combining multistage dynamic Bayesian networks(DBNs)and Monte Carlo simulation.A multistage DBN model for SIL determination with multiple redundant cells is *** models of function inspection test interval and function inspection test stages are alternately connected to form the multistage *** redundant cells can have different M out of N voting system *** automatic modeling of conditional probability between nodes is *** SIL determination of SISs with parameter uncertainty is constructed by using the multistage DBNs and Monte Carlo simulation.A high-pressure SIS in the export of oil wellplatform is adopted to demonstrate the application of the proposed *** SIL and availability of the SIS and its subsystems are *** influence of single subsystem on the SIL and availability of the SIS is *** influence of single redundant element on the SIL and availability of the subsystem is analyzed.A user-friendly SIL determination software with parameter uncertainty is developed on MATLAB graphical user interface.

关键词： Safety integrity level Dynamic Bayesian network Monte Carlo Parameter uncertainty

A NOVEL SIMULTANEOUS NOISE AND INPUT VSWR MATCHING TECHNIQUE FOR BROADBAND LNA

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Journal of Electronics(China) 2010年第4期27卷 446-452页

作者： Nie Zhaohui bao Jingfu Lin ping cai Fajuan University of Electronic Science and Technology of China Chengdu 611731 China China South Industries Group Corporation （Chengdu） Fire Control Technology Center Chengdu 611731 China

The Simultaneous Noise and Input Voltage Standing Wave Ratio (VSWR) Matching (SNIM) condition for Low Noise Amplifier (LNA), in principle, can only be satisfied at a single fre-quency. In this paper, by analyzing the fundamental limitations of the narrowband SNIM technique for the broadband application, the authors present a broadband SNIM LNA systematic design technique. The designed LNA guided by the proposed methodology achieves 10 dB power gain with a low Noise Figure of 0.53 dB. Meanwhile, it provides wonderful input matching of 27 dB across the fre-quency range of 3～5 GHz. Therefore, broadband SNIM is realized.

关键词： Low Noise Amplifier (LNA) Minimum Noise Figure Minimum input VSWR Simultaneous Noise and Input VSWR Matching (SNIM)

Effect of Artificial Electric Field Surface by Wave-Driven Triboelectricity on Anti-Bioadhesion for Riser Protection

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China Ocean Engineering 2024年第3期38卷 483-490页

作者： YI Peng QIU Hong-yuan LI Yong cai bao-ping Javad MOSTAGHIMI ZHANGWen-jie XIAO Wen-sheng College of Mechanical and Electrical Engineering China University of PetroleumQingdao 266580China CNOOC EnerTech Equipment Technology Co. Ltd.Tianjin 300450China Department of Mechanical&Industrial Engineering University of TorontoToronto ONM5S3G8Canada

Biofouling has been a persistent problem in marine riser system, resulting in energy waste and equipment damage. Inthis study, a kind of water wave-driven contact-mode flexible triboelectric nanogeneration has been prepared byusing graphene-doped PDMS as dielectric friction material. When the graphene content is 2%, the average outputvoltage can reach 46 V under the contact frequency 10 Hz. The flexible triboelectric nanogeneration encapsulationmodule is impinged by water waves to generate alternating microelectric field on the riser surface and destroy theadhesion conditions of microorganisms during the biofilm stage. In the biofouling experiments at different stages, thebiofouling area of the platymonas subcordiformis has been reduced by 53%, 62% and 61%. It provides a new ideafor effective treatment of biofouling of mussels, oysters and barnacles attached to risers.

关键词： wave-drive triboelectric nanogeneration alternating microelectric field anti-biofouling

Remaining Useful Life Prediction Method for Multi-Component System Considering Maintenance:Subsea Christmas Tree System as A Case Study

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China Ocean Engineering 2024年第2期38卷 198-209页

作者： WU Qi-bing cai bao-ping FAN Hong-yan WANG Guan-nan RAO Xi GE Weifeng SHAO Xiao-yan LIU Yong-hong CNOOC Safety Technology Services Co. Ltd.Tianjin 300456China College of Mechanical and Electronic Engineering China University of PetroleumQingdao 266580China CNOOC EnerTech Safety&Environmental Protection BranchTianjin 300456China

Maintenance is an important technical measure to maintain and restore the performance status of equipment and ensure the safety of the production process in industrial production,and is an indispensable part of prediction and health ***,most of the existing remaining useful life(RUL)prediction methods assume that there is no maintenance or only perfect maintenance during the whole life cycle;thus,the predicted RUL value of the system is obviously lower than its actual operating *** complex environment of the system further increases the difficulty of maintenance,and its maintenance nodes and maintenance degree are limited by the construction period and working conditions,which increases the difficulty of RUL *** RUL prediction method for a multi-omponent system based on the Wiener process considering maintenance is *** performance degradation model of components is established by a dynamic Bayesian network as the initial model,which solves the uncertainty of insufficient data *** on the experience of experts,the degree of degradation is divided according to Poisson process simulation random failure,and different maintenance strategies are used to estimate a variety of condition maintenance *** example of a subsea tree system is given to verify the effectiveness of the proposed method.

关键词： remaining useful life Wiener process dynamic Bayesian networks maintenance subsea Christmas tree system

Aptamer-Based Antibiotic Electrochemical Detection Platform Using Portable Plastic Gold Electrode and Multichannel Chip

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Chinese Journal of Chemistry 2024年第2期42卷 171-176页

作者： Yin bao Kaiwei cai Yichen Liu Bingling Li Changchun Institute of Applied Chemistry Chinese Academy of SciencesChangchunJilin 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefeiAnhui 230026China

The development of accurate,rapid and practical electrochemical sensing technology for antibiotic detection has an important application prospect in many fields such as food safety,environmental monitoring,medical and health *** this research,kanamycin specific DNA aptamer and its partially complementary short chain were self-assembled onto the surface of an integrated portable plastic gold electrode(PGE)by Au-s bond,and a simple kanamycin electrochemical biosensor interface was *** the same time,the epoxy resin channel layer was designed,and the auxiliary instrument was set up independently in the laboratory,which could help to measure and analyze eight groups of samples automatically in *** quantitative analysis results showed that in 20 min,the sensor had a good linear relationship between the peak current change of square wave voltammetry and the negative logarithm of kanamycin concentration when kanamycin concentration was in the range of 1-10o0μmol/L,and the detection limit could reach 0.40μmol/*** addition,the discrimination could be achieved within 5 min in the real-time analysis *** sensor had a simple construction method,good selectivity and stability,and could be used for rapid or real-time detection of kanamycin residues in actual water samples,which provided a new direction for the practical detection of kanamycin in environmental watersamples.

关键词： Biosensor Aptamer Antibiotics Electroanalysis DNA

Module Structures on U(ε^(-))for the Euclidean Algebra

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Algebra Colloquium 2024年第1期31卷 49-56页

作者： Yixin bao Yan'an cai School of Sciences Harbin Institute of Technology ShenzhenGuangdong 518055China Department of Mathematics Soochow University SuzhouJiangsu 215006China

We classify modules which are free of rank 1 when restricted to the negative part for the Euclidean Lie *** and necessary conditions for the simplicity of these modules are *** these modules we construct modules which... 详细信息

关键词： Euclidean algebra free module simple module nonweight module

Design and performance evaluation of a large field-of-view dual-particle time-encoded imager based on a depth-of-interaction detector

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Nuclear Science and Techniques 2024年第4期35卷 1-14页

作者： Dong Zhao Xu-Wen Liang ping-Kun cai Wei Cheng Wen-bao Jia Da-Qian Hei Qing Shan Yong-Sheng Ling Chao Shi Department of Nuclear Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211106China Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions Suzhou 215000China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China

Time-encoded imaging is useful for identifying potential special nuclear materials and other radioactive sources at a *** this study,a large field-of-view time-encoded imager was developed for gamma-ray and neutron source hotspot imaging based on a depth-of-interaction(DOI)*** imager primarily consists of a DOI detector system and a rotary dual-layer cylindrical coded *** EJ276 plastic scintillator coupled with two SiPMs was designed as the DOI detector to increase the field of view and improve the imager *** difference in signal time at both ends and the log of the signal amplitude ratio were used to calculate the interaction position *** position resolution of the DOI detector was calibrated using a collimated Cs-137 source,and the full width at half maximum of the reconstruction position of the Gaussian fitting curve was approximately 4.4 *** DOI detector can be arbitrarily divided into several units to independently reconstruct the source distribution *** unit length was optimized via Am-Be source-location experiments.A multidetector filtering method is proposed for image *** method can effectively reduce image noise caused by poor DOI detector position *** vertical field of view of the imager was(-55°,55°)when the detector was placed in the center of the coded mask.A DT neutron source at 20 m standoff could be located within 2400 s with an angular resolution of 3.5°.

关键词： Time-encoded imager Depth-of-interaction detector Dual-particle imaging Hotspot imaging

An isolated symmetrical 2T2R cell enabling high precision and high density for RRAM-based in-memory computing

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Science China(Information Sciences) 2024年第5期67卷 287-294页

作者： Yaotian LING Zongwei WANG Yuhang YANG Lin bao Shengyu bao Qishen WANG Yimao cai Ru HUANG School of Integrated Circuits Beijing Advanced Innovation Center for Integrated Circuits Peking University State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications

In-memory computing(IMC), leveraging emerging memories, holds significant promise in overcoming memory limitations and improving energy efficiency. However, the prevailing IMC array structure based on serially connected transistors and memory cells(1T1R/2T2R), along with the signed weight mapping scheme, can lead to asymmetrical weight sensing issues(AWS) due to electrical asymmetry within the1T1R/2T2R structure, particularly in highly scaled cells where the transistor's resistance becomes significant. In this paper, we propose and fabricate an electrically symmetric memory cell based on a physically isolated 2T2R structure for IMC. This design aims to enhance the precision and density of RRAM-based IMC arrays. The 2T2R cells are manufactured using the back-end-of-line(BEOL) process of a commercial40 nm technology platform. The feasibility of this design is verified through measured and simulated results,showcasing its capability to address the issue of AWS. Compared to conventional 2T2R cells, this design achieves a considerably smaller transistor footprint without compromising accuracy, while also improving integration density by 42.2%. These innovative memory cell advancements have the potential to further advance high-energy-efficient IMC technology.

关键词： RRAM 2T2R multi-level storage weight asymmetry in-memory computing

Experimental and numerical study of hypervelocity impact damage on composite overwrapped pressure vessels

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Defence Technology（防务技术） 2024年第1期31卷 58-72页

作者： Yong-Pan Duan Run-Qiang Chi bao-Jun Pang Yuan cai Hypervelocity Impact Research Center Harbin Institute of TechnologyHarbin150080China College of Science Heilongjiang University of Science and TechnologyHarbin 150022China

Ground-based tests are important for studying hypervelocity impact(HVI)damage to spacecraft pressure vessels in the orbital debris *** analyzed the damage to composite overwrapped pressure vessels(COPVs)in the HVI tests and classified the damage into non-catastrophic damage and catastrophic *** proposed a numerical simulation method to further study non-catastrophic damage and revealed the characteristics and mechanisms of non-catastrophic damage affected by impact conditions and internal *** fragments of the catastrophically damaged COPVs were collected after the *** crack distribution and propagation process of the catastrophic ruptures of the COPVs were *** findings contribute to understanding the damage characteristics and mechanisms of COPVs by HVIs.

关键词： Orbital debris Hypervelocity impact Composite overwrapped pressure vessels Damage mechanisms