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Preparing cyclic polymers at high concentrations via self-folding cyclization technique by adjusting the contents of hydrophilic units in linear precursors

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Chinese Chemical Letters 2024年第2期35卷 283-288页

作者： Hao Zha Zuowei wang Chao Liu Chunyan hong Department of Polymer Science and Engineering University of Science and Technology of ChinaHefei 230026China Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China

Cyclic polymers are a class of polymers that feature endless topology,and the synthesis of cyclic polymers has attracted the attention of many ***,cyclic polymers were efficiently constructed by self-folding cyclization technique at high *** poly((oligo(ethylene glycol)acrylate)-co-(dodecyl acrylate))(P(OEGA-co-DDA))precursors with different ratios of hydrophilic and hydrophobic moieties were synthesized by reversible addition-fragmentation chain transfer(RAFT)polymerization using a bifunctional chain transfer agent with two anthryl end *** amphiphilic linear precursors underwent the self-folding process to generate polymeric nanoparticles in *** irradiating the aqueous solution of the nanoparticles with 365 nm UV light,cyclic polymers were synthesized successfully via coupling of anthryl *** effects of the ratios of hydrophilic and hydrophobic moieties in linear P(OEGA-co-DDA)copolymers and polymer concentration on the purity of the obtained cyclic polymers were explored in detail via ^(1)H nuclear magnetic resonance(^(1)H NMR),dynamic light scattering(DLS),UV‒visible(vis)analysis,three-detection size exclusion chromatography(TD-SEC)and transmission electron microscopy(TEM).It was found that by adjusting the content of the hydrophilic segments in linear precursors,single chain polymeric nanoparticles(SCPNs)can be generated at high polymer ***,cyclic polymers with high purity can be constructed *** method overcomes the limitation of traditional ring-closure method,which is typically conducted in highly dilute conditions,providing an efficient method for the scalable preparation of cyclic polymers.

关键词： Cyclic polymers Self-folding cyclization technique Single chain polymeric nanoparticles RAFT polymerization Direct visualization

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

Detection and analysis of serum bile acid profile in patients with colonic polyps

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world Journal of Clinical Cases 2024年第13期12卷 2160-2172页

作者： Xin Ji hong Chen School of Medicine Southeast UniversityNanjing 210009Jiangsu ProvinceChina Department of Gastroenterology Zhongda Hospital Southeast UniversityNanjing 210009Jiangsu ProvinceChina

BACKGROUND Analyzing the variations in serum bile acid(BA)profile can provide a certain biological basis for early warning and prevention of various *** is currently no comprehensive study on the relationship between the serum BA profile and colonic *** To study the serum BA profile detection results of patients with colonic polyps,and analyze the correlation between BA and colonic *** From January 1,2022,to June 1,2023,204 patients with colonic polyps who were diagnosed and treated at Zhongda Hospital Southeast University were chosen as the study subjects,and 135 non-polyp people who underwent physical examination were chosen as the control *** all patients'clinical information,typical biochemical indicators,and BA *** Compared with the control group,the serum levels of taurocholic acid,glycocholic acid,glycochenodeoxycholic acid,and taurochenodeoxycholic acid in the colonic polyp group were significantly higher than those in the control group,while the content of deoxycholic acid(DCA)was lower than that in the control group(Pwhen colonic polyps were analyzed as subgroups,it was shown that there was a strong correlation between changes in the BA profile and polyp diameter,location,morphology,pathological kind,*** The serum BA profile showed significant changes in patients with colonic polyps,with a significant increase in primary conjugated BA content and a decrease in secondary free bile acid DCA *** is a certain correlation between primary free BA and pathological parameters of polyps.

关键词： Serum Bile acid profile Colonic polyps Bile acid metabolism

Jet formation and penetration performance of a double-layer charge liner with chemically-deposited tungsten as the inner liner

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Defence Technology（防务技术） 2024年第3期33卷 374-385页

作者： Bihui hong wenbin Li yiming Li Zhiwei Guo Binyou yan Ministerial Key Laboratory of ZNDy Nanjing University of Science and TechnologyNanjing 210094China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China Xiamen Tungsten Co. Ltd.Xiamen 361004China

This paper proposes a type of double-layer charge liner fabricated using chemical vapor deposition(CVD)that has tungsten as its inner *** feasibility of this design was evaluated through penetration ***-layer charge liners were fabricated by using CVD to deposit tungsten layers on the inner surfaces of pure T2 copper *** microstructures of the tungsten layers were analyzed using a scanning electron microscope(SEM).The feasibility analysis was carried out by pulsed X-rays,slug-retrieval test and static penetration *** shaped charge jet forming and penetration law of inner tungsten-coated double-layer liner were studied by numerical simulation *** results showed that the double-layer liners could form well-shaped *** errors between the X-ray test results and the numerical results were within 11.07%.A slug-retrieval test was found that the retrieved slug was similar to a numerically simulated *** with the traditional pure copper shaped charge jet,the penetration depth of the double-layer shaped charge liner increased by 11.4% and>10.8% *** summary,the test results are good,and the numerical simulation is in good agreement with the test,which verified the feasibility of using the CVD method to fabricate double-layer charge liners with a high-density and high-strength refractory metal as the inner liner.

关键词： Shaped charge Chemical vapor deposition Tungsten Double-layer charge liner X-ray Penetration

Multiple factors influencing high-purity indium electrolytic refining

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Chinese Journal of Chemical Engineering 2024年第7期71卷 148-160页

作者： hong-Qiang Fan Fei Li hong-Xing Zheng wu-ji Pan Mei-Zhen wu yashar Behnamian Ju-Bo Peng Dong-Hai Lin State Key Laboratory of Advanced Special Steel&School of Materials Science and Engineering Shanghai UniversityShanghai 200444China Shanghai Engineering Research Center for Integrated Circuits and Advanced Display Materials Shanghai UniversityShanghai 200444China Research&Development Center Yunnan Tin Group(Holding)Limited CompanyKunming 650032China Department of Chemical and Materials Engineering University of AlbertaEdmonton T6G 2V4AlbertaCanada School of Energy and Materials Shanghai Key Laboratory of Engineering Materials Application and EvaluationShanghai Polytechnic UniversityShanghai 201209China

The effects of various contaminants in the electrolytic refinement of indium were investigated using a glow discharge mass spectrometer(GDMS).The effects of several factors such as the indium ion(In3+)concentration,the sodium chloride(NaCl)concentration,the current density,the gelatin concentration,the pH,and the electrode distance,were *** variations in impurity levels concerning gelatin concentration were *** the gelatin and In3+concentration were moderately positively correlated with the Pb *** Sb concentration was associated positively with the NaCl concentration,while the Ti concentration had an adverse correlation with the NaCl *** Bi element content was positively linked to the electrode *** the current density increased,Cu,Pb,and Bi impurities initially rose and then eventually ***,a critical current density of 45 A·m^(-2) was identified in this behavior.

关键词： High-purity indium Electrolysis Multiple factors Electrochemistry Purification

A robust viscoelastic surfactant tolerating 20% HCl up to 150℃ for oil well stimulation

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Petroleum Science 2024年第3期21卷 1865-1874页

作者： Ji wang Ning Qi hong-yao yin yu-Jun Feng Polymer Research Institute State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu610065SichuanPR.China Tianfu yongxing Laboratory New Theory and Technology of CO_(2) Capture Research CenterChengdu610065SichuanPR China School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongPR China

Viscoelastic surfactants(VES)are often used as viscous diverters in acidizing stimulation to prolong the acid consumption time and maximize zonal coverage of the acid for improving well ***,the ceiling temperature of commercial VES cannot exceed 120℃in practical use because of the poor thermal stability and fragile molecular structure,hindering their implementation in hightemperature oil reservoirs,i.e.,≥150℃.Here we synthesized a novel C22-tailed diamine,N-erucaminopropyl-N,N-dimethylamine(EDPA),and examined comparatively its rheological behavior,assemblies morphology and molecular stability in 20 wt%HCl with a commercial VES,erucyl dimethyl amidopropyl betaine(EDAB).The feasibility of EDPA for acidizing stimulation was assessed by acid etching of carbonate rock with its HCl solution at 150℃.Rheological results showed that the 2.5 wt%EDPA—20 wt%HCl solution maintains stable viscosity of 90 m Pa s at 150℃for 60 min,while that of 2.0 wt%EDAB HCl solution is just 1 m Pa s under identical conditions.1H NMR spectra and cryo-TEM observations revealed that the chemical structure and self-assembled architectures of EDPA remained intact in such context,but the EDAB suffered from degradation due to the hydrolysis of the amide group,accounting for the poor heat-resistance and *** reaction rate of 2.5 wt%EDPA HCl solution with carbonate rock was one order of magnitude lower than that of 20 wt%HCl solution at 150℃,underpinning the potential of EDPA to be used in the high-temperature reservoirs *** work improved the thermal tolerance of VES in highly concentrated HCl solution,paving a feasible way for the acidization of high-temperature reservoir environments(~150℃).

关键词： Viscoelastic surfactants Thermal stability Self-diverting acid wormlike micelles Acidizing stimulation

Multi-Scale Fusion Model Based on Gated Recurrent Unit for Enhancing Prediction Accuracy of State-of-Charge in Battery Energy Storage Systems

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Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 405-414页

作者： Hao Liu Fengwei Liang Tianyu Hu Jichao hong Huimin Ma School of Computer and Communication Engineering University of Science and Technology BeijingBeijingChina School of Mechanical Engineering University of Science and Technology BeijingBeijingChina IEEE

Accurate prediction of the state-of-charge(SOC)of battery energy storage system(BESS)is critical for its safety and lifespan in electric *** overcome the imbalance of existing methods between multi-scale feature fusion and global feature extraction,this paper introduces a novel multi-scale fusion(MSF)model based on gated recurrent unit(GRU),which is specifically designed for complex multi-step SOC prediction in practical *** correlation analysis is first employed to identify SOC-related *** parameters are then input into a multi-layer GRU for point-wise feature ***,the parameters undergo patching before entering a dual-stage multi-layer GRU,thus enabling the model to capture nuanced information across varying time ***,by means of adaptive weight fusion and a fully connected network,multi-step SOC predictions are *** extensive validation over multiple days,it is illustrated that the proposed model achieves an absolute error of less than 1.5%in real-time SOC prediction.

关键词： Electric vehicle battery energy storage system(BESS) state-of-charge(SOC)prediction gated recurrent unit(GRU) multi-scale fusion(MSF).

Evaluation of internal void related defects in reinforced concrete slab using electromagnetic wave properties

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Earthquake Engineering and Engineering Vibration 2024年第3期23卷 525-535页

作者： Minju Kang Jinyoung hong Taemin Lee Doyun Kim Hajin Choi School of Architecture Soongsil UniversitySeoul 06978Republic of Korea

This study aims to develop a damage-detection algorithm based on the electromagnetic wave properties inside a reinforced concrete *** proposed method involves employing two algorithms based on data measured using ground-penetrating radar—a common electromagnetic wave method in civil *** possible defect area was identified based on the energy dissipated by the damage in the frequency-wavenumber domain,with the damage localized using the calculated relative permittivity of the *** proposed method was verified through a finite difference time-domain-based numerical analysis and a testing slab with artificial *** a result of verification,the proposed method quickly identified the presence of damage inside the concrete,especially for honeycomb-like defects located at the top of the *** study has practical significance in scanning structures over a large area more quickly than other non-destructive testing methods,such as ultrasonic methods.

关键词： GPR concrete defect electromagnetic wave relative permittivity non-destructive testing(NDT)

Video caching and scheduling with edge cooperation

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Digital Communications and Networks 2024年第2期10卷 450-460页

作者： Zhidu Li Fuxiang Li Tong Tang hong Zhang Jin yang School of Communication and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing400065China Advanced Network and Intelligent Connection Technology Key Laboratory of Chongqing Education Commission of China Chongqing400065China Key Laboratory of Ubiquitous Sensing and Networking in Chongqing Chongqing400065China

In this paper,we explore a distributed collaborative caching and computing model to support the distribution of adaptive bit rate video *** aim is to reduce the average initial buffer delay and improve the quality of user *** the difference between global and local video popularities and the time-varying characteristics of video popularity,a two-stage caching scheme is proposed to push popular videos closer to users and minimize the average initial buffer *** on both long-term content popularity and short-term content popularity,the proposed caching solution is decouple into the proactive cache stage and the cache update *** the proactive cache stage,we develop a proactive cache placement algorithm that can be executed in an off-peak *** the cache update stage,we propose a reactive cache update algorithm to update the existing cache policy to minimize the buffer *** results verify that the proposed caching algorithms can reduce the initial buffer delay efficiently.

关键词： Video service Distributed and collaborative caching Long-term popularity Short-term popularity