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High temperature Iron Ethylene Polymerization Catalysts Bearing N,N,N'-2-(1-(2,4-Dibenzhydryl-6-fluorophenylimino)ethyl)-6-(1-(arylphenylimino)ethyl)pyridines

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Chinese Journal of Polymer Science 2024年第2期42卷 188-201,I0007页

作者： Chantsalnyam Bariashir Qiu-Yue Zhang Bayasgalan ulambayar Gregory A.Solan tong-Ling Liang Wen-Hua Sun Institute of Chemistry and Chemical technology Mongolian Academy of SciencesUlaanbaatar13330Mongolia Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science Institute of ChemistryChinese Academy of SciencesBeijing100190China Department of Chemistry University of LeicesterUniversity RoadLeicesterLE17RHUK State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou730000China

the N,N,N'-ferrous chloride complexes,[2-{CMeN(2,4-(CHPh)_(2)-6-FC_(6)H_(2))}-6-(CMeNAr)C_(5)H_(3)N]FeCl_(2)(Ar=2,6-Me_(2)C_(6)H_(3) Fe1,2,6-Et_(2)C_(6)H_(3)Fe2,2,6-^(i)Pr_(2)C_(6)H_(3) Fe3,2,4,6-Me_(3)C_(6)H_(2) Fe4 and 2,6-Et_(2)-4-MeC_(6)H_(2) Fe5),each possessing one N-2,4-dibenzhydryl-6-fluorophenyl group,were readily synthesized from their respective unsymmetrical bis(imino)pyridines,*** identification of Fe2 highlighted the variation in the steric properties provided by the dissimilar N-aryl *** pre-treatment with either MAO or MMAO,complexes Fe1-Fe5 all displayed,at an operating temperature of 80℃,high activities for ethylene polymerization with levels falling in the order:Fe4> Fe1> Fe5> Fe2> ***,Fe4/MAO displayed the highest activity of 1.94×10^(7) g_(PE)·mol_(Fe)^(-1)·h^(-1) of the study with only a modest loss in performance at 90℃.Generally,the resulting polyethylenes were highly linear(t_(m) range:122-132℃),narrowly disperse and of low molecular weight(M_(w) range:6.73-46.04kg·mol^(-1)),with the most sterically hindered Fe3 forming the highest molecular weight polymer of the ***-group analysis by ^(1)H-and ^(13)CNMR spectroscopy revealed saturated alkyl(n-propyl and i-propyl) and unsaturated vinyl chain ends indicative of the role of both β-H elimination and chain transfer to aluminum as termination *** comparison with previou sly reported iron precatalysts with similar tridentate ligand skeletons,it is evident that the introduction of a large benzhydryl group in combination with a fluorine as the ortho-substituents of one N-aryl group has the effect of enhancing thermal stability of the iron polymerization catalyst whilst maintaining appreciable polymer molecular weight.

关键词： Iron catalyst Ethylene polymerization Linear polyethylene Fluoride effect thermal stability

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Science Missions Using CubeSats

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空间科学学报 2020年第4期40卷 443-461页

作者： SEYEDABADI M E FALANGA M AZAM M BARESI N FLÉRON R JANtARACHOtE V JUAREZ ORtIZ V A JULCA YAYA J J LANGER M MANUtHASNA S MARtINOD N MUGHAL M R NOMAN M PARK J PIMNOO A PRAKS J REYNERI L SANNA A ŞIŞMAN tÇ SOME J ulambayar t YU Xiaozhou DONG Xiaolong BALDIS L Asia-Pacific Space Cooperation Organization 100070 BeijingChina International Space Science Institute-Beijing 100190 BeijingChina International Space Science Institute 3012 BernSwitzerland Bangladesh Space Research and Remote Sensing Organization 1207 DhakaBangladesh Japan Aerospace Exploration Agency Institute of Space Astronautical Science252-5210 TokyoJapan technical University of Denmark 2800 LyngbyDenmark Department of Electrical Engineering Faculty of EngineeringPrince of Songkla University90112 SongkhlaThailand National Commission of Aerospace Research and Development 15046 San IsidroPeru technical University of Munich 80333 MunichGermany Mahanakorn University of technology 10530 BangkokThailand Swiss Federal Institute of technology Lausanne 1015 LausanneSwitzerland Institute of Space technology 44000 IslamabadPakistan Korea Astronomy and Space Science Institute 34055 DaejeonSouth Korea Geo-Informatics and Space technology Development Agency 10210 BangkokThailand Department of Electronics and Nanoengineering Aalto University02150 EspooFinland Department of Electronics and telecommunications Polytechnic of Turin10129 TurinItaly Department of Physics University of Cagliari09042 MonserratoItaly Department of Astronautical Engineering University of Turkish Aeronautical Association06790 AnkaraTurkey Nanosatellite Development Laboratory National University of Mongolia210646 UlaanbaatarMongolia Dalian University of technology 116024 DalianChina National Space Science Center 100190 BeijingChina

As the role of missions and experiments carried out in outer space becomes more and more essential in our understanding of many earthly problems,such as resource management,environmental problems,and disaster management,as well as space science questions,thanks to their lower cost and faster development process CubeSats can benefit humanity and therefore,young scientists and engineers have been motivated to research and develop new CubeSat *** very long after their inception,CubeSats have evolved to become accepted platforms for scientific and commercial *** last couple of years showed that they are a feasible tool for conducting scientific experiments,not only in the Earth orbit but also in the interplanetary *** many countries,a CubeSat mission could prompt the community and young teams around the world to build the national capacity to launch and operate national space *** paper presents an overview of the key scientific and engineering gateways opened up to the younger scientific community by the advent and adaptation of new technology into CubeSat *** role of cooperation and the opportunities for capacity-building and education are also ***,the present article also aims to provide useful recommendations to scientists,early-career researchers,engineers,students,and anyone who intends to explore the potential and opportunities offered by CubeSats and CubeSats-based missions.

关键词： CubeSat Space science Small satellites for space science Education Earth observation

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Preparation of microparticles and nanoparticles using membrane-assisted dispersion,micromixing,and evaporation processes

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Particuology 2024年第1期84卷 30-44页

作者： Goran t.Vladisavljevic Chemical Engineering Department Loughborough UniversityLoughboroughLeicestershire LE113TUUnited Kingdom

Synthetic microporous membranes are increasingly used for energy-efficient and controlled production of micro-and nanoparticles and micro-and nanoemulsions with tuneable morphology and physico-chemical properties through various micromixing,emulsification,and evaporation *** emul-sification processes,the membrane pores are used for dispersed phase injection and size-controlled generation of droplets and droplet-templated *** micromixing processes,membrane is utilised as a micromixer for mixing two miscible liquids,usually solvent and antisolvent-rich solutions,which leads to the creation of supersaturation and subsequent nanoprecipitation or *** mem-brane evaporation processes,membrane is used to prevent phase dispersion while allowing efficient molecular diffusion of solvent and/or antisolvent vapour through gas-filled *** dispersion processes can be operated continuously by decoupling shear stress on the membrane surface from cross flow using tube insets,flow pulsations,swirling flow,membrane oscillations or membrane *** generation and solidification can be performed continuously in a single pass by connecting membrane module with a downstream *** dispersion processes can be used for pro-duction of nanoparticles such as nanovesicles(liposomes,micelles,ethosomes,and niosomes),nanogels,polymeric,lipid and metallic nanoparticles,and *** main advantages of membrane-assisted particle generation are in low energy consumption,controlled geometry and hydrodynamic conditions at the microscale level,flexible throughput due to modular and scalable design of membrane devices,and a wide choice of available microporous membranes with various wall porosities,wetta-bilities,pore sizes,and pore morphologies to suit different applications.

关键词： Nanoparticles Microparticles Nanoemulsions Microemulsions Microporous membrane Crystallisation Flash nanoprecipitation Emulsification Zero liquid discharge

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Late Ordovician Mass Extinction: Earth, fire and ice

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National Science Review 2024年第1期11卷 51-65页

作者： David A.t.Harper Palaeoecosystems Group Department of Earth SciencesDurham University

the Late Ordovician Mass Extinction was the earliest of the ‘big’ five extinction events and the earliest to affect the trajectory of metazoan life. two phases have been identified near the start of the Hirnantian period and in the middle. It was a massive taxonomic extinction, a weak phylogenetic extinction and a relatively benign ecological extinction. A rapid cooling, triggering a major ice age that reduced the temperature of surface waters, prompted a drop in sea level of some 100 m and introduced toxic bottom waters onto the shelves. these symptoms of more fundamental planetary processes have been associated with a range of factors with an underlying driver identified as volcanicity. Volcanic eruptions, and other products, may have extended back in time to at least the Sandbian and early Katian, suggesting the extinctions were more protracted and influential than hitherto documented.

关键词： Ordovician LOME paleoecology palaeobiogeography biotas

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Beta-lactam antibiotic resistance among Escherichia coli isolates from patients with urinary tract infections in Vietnam:A systematic review and meta-analysis

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Asian Pacific Journal of tropical Medicine 2024年第6期17卷 243-255,I0001-I0003页

作者： Dat t Nguyen Princess Margaret Cancer Centre University Health NetworkTorontoOntarioCanada

Objective:to investigate the evolving patterns of antimicrobial resistance against beta-lactam antibiotics in Escherichia coli isolates from urinary tract infection patients in Vietnam,covering the period from 2005 to ***:29 Descriptive studies published between 2010 and 2022 in English and Vietnamese were included in the *** on resistance rates to beta-lactam antibiotics,including cephalosporins and carbapenems,were extracted and *** pooled resistance rates were calculated using random-effects *** trends in resistance were assessed using linear regression ***:Among the beta-lactam antibiotics studied,Escherichia coli exhibited varying levels of resistance,with cephalosporins showing higher resistance rates compared to *** pooled resistance rates were 66%for cefotaxime,65%for ceftriaxone,54%for ceftazidime,and 56%for *** contrast,carbapenems demonstrated lower resistance rates,with weighted pooled resistance rates ranging from 3%to 4%for meropenem,ertapenem,and *** rates were also observed for amoxicillin/clavulanate(35%),ticarcillin/clavulanate(26%),and piperacillin/tazobactam(12%).Significant annual increases in resistance were noted for imipenem(0.56%,Pthis study highlights the critical issue of antimicrobial resistance in urinary tract infections in Vietnam and emphasizes the importance of prudent antibiotic use and the regular monitoring of resistance *** insights are useful for guiding healthcare professionals in optimizing treatment strategies and for policymakers in formulating evidence-based clinical guidelines to combat antibiotic resistance effectively.

关键词： Antimicrobial resistance Urinary tract infection Vietnam

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A novel strategy for ionomer coating of Ag nanoparticles used for the electrochemical reduction of CO2 to CO in a membrane electrode assembly

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National Science Review 2024年第2期11卷 94-95页

作者： Alexis t.Bell Department of Chemical and Biomolecular Engineering University of California

the electrochemical reduction of the CO2reaction （CO2RR） offers an attractive means for converting the carbon content of CO2, released from a stationary source or the atmosphere, into fuels and chemicals [1]. Utiliz...

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A deep neural network based surrogate model for damage identification in full-scale structures with incomplete noisy measurements

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Frontiers of Structural and Civil Engineering 2024年第3期18卷 393-410页

作者： tram BUI-NGOC Duy-Khuong LY tam t tRUONG Chanachai tHONGCHOM t.NGUYEN-tHOI Laboratory for Computational Mechanics Institute for Computational Science and Artificial IntelligenceVan Lang UniversityHo Chi Minh City 70000Vietnam Faculty of Mechanical-Electrical and Computer Engineering School of TechnologyVan Lang UniversityHo Chi Minh City 70000Vietnam Faculty of Civil Engineering School of TechnologyVan Lang UniversityHo Chi Minh City 70000Vietnam Department of Computer Science Aarhus UniversityAarhus 8000Denmark thammasat University research unit in structural and foundation engineering Department of Civil EngineeringThammasat UniversityPathumthani 12120Thailand Laboratory for Applied and Industrial Mathematics Institute for Computational Science and Artificial IntelligenceVan Lang UniversityHo Chi Minh City 70000Vietnam thammasat School of Engineering Thammasat UniversityPathumthani 12120Thailand

the paper introduces a novel approach for detecting structural damage in full-scale structures using surrogate models generated from incomplete modal data and deep neural networks(DNNs).A significant challenge in this field is the limited availability of measurement data for full-scale structures,which is addressed in this paper by generating data sets using a reduced finite element(FE)model constructed by SAP2000 software and the MAtLAB programming *** surrogate models are trained using response data obtained from the monitored structure through a limited number of measurement *** proposed approach involves training a single surrogate model that can quickly predict the location and severity of damage for all potential *** achieve the most generalized surrogate model,the study explores different types of layers and hyperparameters of the training algorithm and employs state-of-the-art techniques to avoid overfitting and to accelerate the training *** approach’s effectiveness,efficiency,and applicability are demonstrated by two numerical *** study also verifies the robustness of the proposed approach on data sets with sparse and noisy measured ***,the proposed approach is a promising alternative to traditional approaches that rely on FE model updating and optimization algorithms,which can be computationally *** approach also shows potential for broader applications in structural damage detection.

关键词： vibration-based damage detection deep neural network full-scale structures finite element model updating noisy incomplete modal data

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CompactChain:an efficient stateless chain for UtXO-model blockchain

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Frontiers of Computer Science 2024年第2期18卷 167-179页

作者： B Swaroopa REDDY t Uday Kiran REDDY Department of Electrical Engineering Indian Institute of Technology HyderabadHyderabadTelangana 502285India

In this work,we propose a stateless blockchain called CompactChain,which compacts the entire state of the UtXO(Unspent transaction Output)based blockchain systems into two RSA *** first accumulator is called transaction Output(tXO)commitment which represents the tXO *** second one is called Spent transaction Output(StXO)commitment which represents the StXO *** this work,we discuss three algorithms:(i)to update the tXO and StXO commitments by the *** miner also provides the proofs for the correctness of the updated commitments;(ii)to prove the transaction’s validity by providing a membership witness in tXO commitment and non-membership witness against StXO commitment for a coin being spent by a user;(iii)to update the witness for the coin that is not yet spent;the experimental results evaluate the performance of the CompactChain in terms of time taken by a miner to update the commitments and time taken by a validator to verify the commitments and validate the *** compare the performance of CompactChain with the existing state-of-the-art works on stateless *** shows a reduction in commitments update complexity and transaction witness size which inturn reduces the mempool size and propagation latency without compromising the system throughput(transactions per second(tPS)).

关键词： stateless blockchain RSA Accumulator StXO commitment tXO commitment UtXO Non-interactive Proof of Exponentiation(NI-PoE) transactions per second(tPS)

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Evaluation of red soil-bentonite mixtures for compacted clay liners

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 697-710页

作者： A.S.Devapriya t.thyagaraj Department of Civil Engineering Indian Institute of Technology MadrasChennai600036India

Compacted clay liners are an integral part of the waste landfills,which are provided to contain the leachate within the landfills and protect the surrounding ***,locally available natural soils are used for the construction of compacted clay liners if they satisfy the design ***,not all soils in their natural state satisfy all the design criteria for the liner ***,there is a definite need to modify the locally available natural soils by blending with bentonite to meet the required design criteria for the *** view of this,the present study evaluates the suitability of an Indian red soil enhanced with bentonite as a liner *** achieve this,a series of experiments were carried out using locally available red soil and ***,the suitability of the red soil was evaluated as a liner *** experimental results showed that the red soil met all the selection criteria stipulated by the Environmental Protection Agencies(EPAs)for the liners except the hydraulic conductivity ***,the red soil was mixed with bentonite contents of 10%,20%and 30%,and the red soil-bentonite mixtures were evaluated for their suitability for liners in their compacted ***,as the liners in the arid and semi-arid regions are subjected to moisture variations due to seasonal moisture fluctuations and other factors,the red soil-bentonite mixtures were subjected to wetdry cycles,and their suitability was evaluated after wet-dry *** experimental results revealed that all the red soil-bentonite mixtures met the stipulated EPA criteria for the liners in the as-compacted ***,the red soil-bentonite mixtures with 20%and 30%bentonite contents only satisfied the hydraulic conductivity requirement even after wet-dry *** experimental findings were supplemented with the microstructural insights captured through digital camera images,scanning electron microscopy(SEM),and mercury intrusion porosimetry(M

关键词： Compacted clay lines Hydraulic conductivity Wet-dry cycles Microstructure

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Physics of porous materials under extreme laser-generated conditions

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Matter and Radiation at Extremes 2024年第3期9卷 1-3页

作者： V.t.tikhonchuk S.Weber Extreme Light Infrastructure ERIC ELI Beamlines Facility25241 DolníBrezanyCzech Republic CELIA University of Bordeaux33405 TalenceFrance

Porous materials offer unique possibilities for the production of plasmas with controlled density profiles for experiments on laser–matter *** are of growing relevance to many applications,such as inertial confinement fusion,fundamental research,and secondary *** the processes of transformation of a porous solid into a plasma is of fundamental interest and is needed for producing materials with desired properties.

关键词： interaction. properties. porous

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