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Functionalized Hyperbranched Aliphatic Polyester Polyols: Synthesis,Properties and Applications

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Chinese Journal of Polymer Science 2022年第12期40卷 1567-1585,I0006页

作者： aleksei Maksimov Gennadii Kutyrev Kazan National Research Technological University Department of General Chemical TechnologiesKazan 420015Russia

Recently, hyperbranched polymers(HBPs), which differ significantly in structure and properties from linear, cross-linked and branched analogs, have become increasingly important. HBP have a spatial unloaded core and a shell of branched monomer units(dendrons), in which functional groups are predominantly located in the surface layer. The size of macromolecules ranges from 2 nm to 100 nm. Currently, there are a fairly large number of publications in the literature devoted to the modification of hyperbranched polyester polyols with various functional groups and the assessment of the potential for their use. However, there are no review articles on this topic in recent years. In this regard, it is relevant to generalize the latest achievements in the field of synthesis, properties and application of hyperbranched polyester polyols with terminal oxygen, nitrogen, silicon, sulfur and organophosphorus fragments. The advantage of hyperbranched polyester polyols of the Boltorn H series is their industrial availability, biodegradability, nanoscale, non-toxicity and high solubility in various polar solvents due to short monomer units, as well as the presence of reactive terminal hydroxyl groups. Functionalization of hyperbranched polyester polyols at hydroxyl groups is mainly carried out by addition of acid anhydrides, iso(thio)cyanates, alkenes, lactides, lactones, lactams, epoxy compounds or reactions with halogenated compounds(alkyl halides, acid chlorides). In some cases, for the functionalization of polyester polyols special linkers are used, such as acid chlorides of unsaturated or dicarboxylic acids, diisocyanates, etc., which provide covalent bonding of the hyperbranched polymer with the target functional group. The obtained derivatives of hyperbranched polyesters are widely used in such areas as biomedicine, pharmacy, paints and varnishes, they are also used as catalysts, membranes, multifunctional coatings, plasticizers and polymer stabilizers.

关键词： Hyperbranched polymers Hyperbranched polyester polyols Curable coatings Targeted drug delivery Membranes

Function fitting for modeling seasonal normalized difference vegetation index time series and early forecasting of soybean yield

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The Crop Journal 2022年第5期10卷 1452-1459页

作者： Alexey Stepanov Konstantin Dubrovin aleksei Sorokin Far Eastern Agriculture Research Institute Vostochnoe680521 KhabarovskRussia Computing Center of the Far Eastern Branch of the Russian Academy of Sciences 680000 KhabarovskRussia

Forecasting crop yields based on remote sensing data is one of the most important tasks in *** is the main crop in the Russian Far *** is desirable to forecast soybean yield as early as possible while maintaining high *** study aimed to investigate seasonal time series of the normalized difference vegetation index(NDVI) to achieve early forecasting of soybean *** research used data from the Moderate Resolution Image Spectroradiometer(MODIS),an arable-land mask obtained from the VEGA-Science web service,and soybean yield data for 2008-2017 for the Jewish Autonomous Region(JAR) *** approximating functions were fitted to model the NDVI time series:Gaussian,double logistic(DL),and quadratic and cubic *** the period from calendar weeks 22-42(end of May to mid-October),averaged over two districts,the model using the DL function showed the highest accuracy(mean absolute percentage error-4.0%,root mean square error(RMSE)-0.029,P <0.01).The yield forecast accuracy of prediction in the period of weeks 25-30 in JAR municipalities using the parameters of the Gaussian function was higher(P <0.05) than that using the other *** mean forecast error for the Gaussian function was 14.9% in week 25(RMSE was0.21 t ha) and 5.1%-12.9% in weeks 26-30(RMSE varied from 0.06 to 0.15 t ha) according to the2013-2017 *** weeks 31-32,the error was 5.0%-5.4%(RMSE was 0.07 t ha) using the Gaussian parameters and 7.4%-7.7%(RMSE was 0.09-0.11 t ha) for the DL *** the method was applied to municipal districts of other soy-producing regions of the Russian Far *** was0.14-0.32 t hain weeks 25-26 and did not exceed 0.20 t hain subsequent weeks.

关键词： NDVI Function fitting Early prediction Yield Soybean

Potential use of magnesium industrial waste for synthesis of Li and Mg co-doped LiMn_(2)O_(4)nanoparticles as cathode material for Li-ion batteries:Effect of sintering temperature

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Nano Research 2022年第5期15卷 4500-4516页

作者： aleksei Llusco Luis Rojas Svetlana Ushak Mario Grageda Department of Chemical Engineering and Mineral Processing and Center for Advanced Study of Lithium and Industrial Minerals(CELiMIN) Universidad de AntofagastaAntofagasta 1270300Chile

Potential advantages of active electrode nanomaterials have led to development of high energy and power density lithium-ion(Li-ion)***,under increasing demand for critical resources such as lithium and cobalt,it is necessary to use abundant raw materials,which can be obtained from industrial *** this work,purified Mg(OH)_(2)from waste generated in the production of Li2CO3 with natural brines from the Salar de Atacama(Chile)is used as a doping agent for synthesis of LiMn_(2)O_(4)(LMO)spinel octahedral nanoparticles co-doped with excess Li and *** of a pure cubic spinel phase(Fd3m)takes place at 500℃and sintering temperature effect at 580 and 750℃,thus the elemental composition and the structural,morphological,and electrochemical properties are studied in *** electrochemical performance at room temperature is obtained for Li_(1.03)Mg_(0.05)Mn_(1.92)O_(4)spinel sintered at 750℃with an initial discharge capacity of 121.3 mAh·g^(-1)and capacity retention of 94.0%after 100 cycles at C/3.A locally ordered spinel structure is obtained at 750℃,and doping with Mg^(2+)improves structural *** between both effects resulted in a high Li^(+)diffusion rate(1.29×10^(-9)cm^(2)·s^(-1))significantly improving cycling performance at elevated C-rates in 50℃.

关键词： LiMn_(2)O_(4)(LMO)spinel Mg doped excess Li octahedral nanoparticle industrial waste lithium-ion(Li-ion)batteries

Revisiting the LQR Problem of Singular Systems

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IEEE/CAA Journal of Automatica Sinica 2024年第11期11卷 2236-2252页

作者： Komeil Nosrati Juri Belikov aleksei Tepljakov Eduard Petlenkov IEEE the Department of Computer Systems Tallinn University of Technology the Department of Software Science Tallinn University of Technology

In the development of linear quadratic regulator(LQR) algorithms, the Riccati equation approach offers two important characteristics——it is recursive and readily meets the existence condition. However, these attributes are applicable only to transformed singular systems, and the efficiency of the regulator may be undermined if constraints are violated in nonsingular versions. To address this gap, we introduce a direct approach to the LQR problem for linear singular systems, avoiding the need for any transformations and eliminating the need for regularity assumptions. To achieve this goal, we begin by formulating a quadratic cost function to derive the LQR algorithm through a penalized and weighted regression framework and then connect it to a constrained minimization problem using the Bellman's criterion. Then, we employ a dynamic programming strategy in a backward approach within a finite horizon to develop an LQR algorithm for the original system. To accomplish this, we address the stability and convergence analysis under the reachability and observability assumptions of a hypothetical system constructed by the pencil of augmented matrices and connected using the Hamiltonian diagonalization technique.

关键词： DC motor optimal control penalized weighted regression power system quadratic regulator singular system

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Robust Stability Analysis of Smith Predictor Based Interval Fractional-Order Control Systems:A Case Study in Level Control Process

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IEEE/CAA Journal of Automatica Sinica 2023年第3期10卷 762-780页

作者： Majid Ghorbani Mahsan Tavakoli-Kakhki aleksei Tepljakov Eduard Petlenkov Department of Computer Systems Tallinn University of TechnologyTallinn 12618Estonia Faculty of Electrical Engineering K.N.Toosi University of TechnologyTehran ***Iran IEEE

The robust stability study of the classic Smith predictor-based control system for uncertain fractional-order plants with interval time delays and interval coefficients is the emphasis of this *** uncertainties are a type of parametric uncertainties that cannot be avoided when modeling real-world ***,in the considered Smith predictor control structure it is supposed that the controller is a fractional-order proportional integral derivative(FOPID)*** the best of the authors'knowledge,no method has been developed until now to analyze the robust stability of a Smith predictor based fractional-order control system in the presence of the simultaneous uncertainties in gain,time-constants,and time *** three primary contributions of this study are as follows:ⅰ)a set of necessary and sufficient conditions is constructed using a graphical method to examine the robust stability of a Smith predictor-based fractionalorder control system—the proposed method explicitly determines whether or not the FOPID controller can robustly stabilize the Smith predictor-based fractional-order control system;ⅱ)an auxiliary function as a robust stability testing function is presented to reduce the computational complexity of the robust stability analysis;andⅲ)two auxiliary functions are proposed to achieve the control requirements on the disturbance rejection and the noise ***,four numerical examples and an experimental verification are presented in this study to demonstrate the efficacy and significance of the suggested technique.

关键词： Interval uncertainty FOPID controller fractional-order systems robust stability analysis smith predictor

Retrieval of Volcanic Sulfate Aerosols Optical Parameters from AHI Radiometer Data

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Advances in Atmospheric Sciences 2024年第10期41卷 1953-1968页

作者： Andrei FILEI Olga GIRINA aleksei SOROKIN Far-Eastern Center of State Research Center for Space Hydrometeorology«Planeta» Khabarovsk 680000Russia Institute of Volcanology and Seismology Far Eastern Branch of the Russian Academy of Sciences Petropavlovsk-Kamchatsky 683006Russia Computing Center of the Far Eastern Branch of the Russian Academy of Sciences Khabarovsk 680000Russia

This paper presents a method for retrieving optical parameters from volcanic sulfate aerosols from the AHI radiometer on board the Himawari-8 *** proposed method is based on optical models for various mixtures of aerosol components from volcanic clouds,including ash particles,ice crystals,water drops,and sulfate aerosol *** application of multi-component optical models of various aerosol compositions allows for the optical thickness and mass loading of sulfate aerosol to be estimated in the sulfuric cloud formed after the Karymsky volcano eruption on 3 November 2021.A comprehensive analysis of the brightness temperatures of the sulfuric cloud in the infrared bands was performed,which revealed that the cloud was composed of a mixture of sulfate aerosol and water *** models of various aerosol compositions allows for the satellite-based estimation of optical parameters not only for sulfate aerosol but also for the whole aerosol mixture.

关键词： H_(2)SO_(4) volcano Himawari-8 mass loading volcanic ash optical thickness the Karymsky volcano

Cobalt porphyrin immobilized on the TiO_(2) nanotube electrode for CO2 electroreduction in aqueous solution

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Journal of Energy Chemistry 2021年第4期30卷 219-227页

作者： Shengshen Gu aleksei N.Marianov Yuxiang Zhu Yijiao Jiang School of Engineering Macquarie UniversitySydneyNSW 2109Australia

Herein we report CO_(2) electrochemical reduction reaction(CO_(2) ERR)on the cobalt tetraphenylporphyrin(Co TPP)modified TiO_(2) nanotube(TNT)*** was found the axial coordination of drop-casting solvent to Co TPP and the porphyrin structure are the major factors that have significant effects on the catalytic performance of the *** confirmed by spectrophotometric titration,pyridine has a stronger coordination bond to Co TPP than DMF and THF thus leading to the highest efficiency among the dropcasting solvents tested in the *** on the spectrophotometric analysis,possible coordination mechanism between drop-casting solvents and Co TPP is put *** the other hand,introduction of-COOMe substituents in phenyl rings of Co TPP weakens the coordination bond between pyridine and Co TPP as clearly evidenced by deuterium NMR spectra,resulting in a detrimental effect on CO_(2) ***,the manipulation of the coordination environment around the metal center of immobilized catalyst is crucial in designing an efficient electrocatalytic system.

关键词： CO_(2)electroreduction Co porphyrins Immobilization Drop-casting solvent Axial coordination

Effect of TiO_(2) support on immobilization of cobalt porphyrin for electrochemical CO_(2) reduction

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Journal of Materials Science & Technology 2021年第21期80卷 20-27页

作者： Shengshen Gu aleksei N.Marianov Haimei Xu Yijiao Jiang School of Engineering Macquarie UniversitySydneyNSW2109Australia

Electrochemical reduction of CO_(2) is a promising strategy to manage the global carbon balance by transforming CO_(2) into chemicals. The efficiency of CO_(2) electroreduction is largely dependent on the design of hybrid electrode where both support and catalyst govern the performance of the electrolyzer. In this work,TiO_(2) calcined at different temperatures, was used as a support for immobilization of cobalt tetraphenyl porphyrin(CoTPP) and its effect on CO_(2) reduction was studied. It is demonstrated that the crystalline phase of TiO_(2) and doping of TiO_(2) apparently affecting CO_(2) electroreduction. It is found that anatase phase exhibits higher activity and selectivity compared to rutile due to the enhanced conductivity which in turn enables faster electron transfer between the support and CoTPP. As for dopants, the carbon doping in anatase TiO_(2) is proven to further enhance its conductivity, consequently resulting in the enhanced performance. This study implies that the rational design of supports is important for the performance of the hybrid electrode towards electrochemical CO_(2) reduction.

关键词： CO_(2)electroreduction Cobalt porphyrin Immobilization TiO_(2)support Carbon doping

Structural and geochemical features of coal‑bearing sediments and sources of rare element impurities in coals of the Rakovka depression,Primorsky Krai,Russia

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International Journal of Coal Science & Technology 2022年第1期9卷 71-83页

作者： Nikita Popov Igor Chekryzhov Irina Tarasenko Sergery Kasatkin aleksei Kholodov Far East Geological Institute FEB RAS VladivostokRussian Federation

There are known brown coal deposits in Primorsky Krai(Russian Federation),where coals contain rare elements(Ge,U,REE,etc.)up to industrial *** of the known metalliferous coals is the Rakovka coal-bearing depression,located on the southern edge of the Khanka(Prikhankaiskaya)Lowland,with an area of about 70 ***-metal granites with a developed weathering crust are spread in its basement and *** structural conditions forming the depression were studied using measurements of orientations of structural elements(layering,contacts,veins,and dikes)with regard to kinematic conditions of *** coal and host rocks were sampled in sections in the cross strike of the coal *** and dikes cutting them were sampled by separate rock chip *** chemical composition and element content were determined for all *** was found that the adjacent rocks played a major role in the formation of the Rakovka rare-metal-coal *** rare-elements enrichment is not associated with active tectonics,faults,and hydrothermal sources,as was previously ***,it was caused by the hydrogenic and clastogenic removal of these metals from the weathering crust of granites of the depression's flanks and argillated basite dikes cutting the *** hydrogenic nature of the anomalous accumulation of U in sorbed form on organic matter of coals is confirmed by the predominant enrichment of low-ash *** earth elements entered coal seams both in mineral and dissolved forms.A model of REE and uranium input into the coal-bearing sediments of the Rakovka depression was proposed.

关键词： REE Rare metal-coal deposit Accumulation pattern Tectonics