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Role of Electromagnetic Fluctuations in Organic Electronics

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Journal of Electronic Science and Technology 2020年第1期18卷 52-58页

作者： Vladimir M.Mostepanenko Elena N.Velichko Maksim Aleksandrovich Baranov Institute of Physics Nanotechnology and TelecommunicationsPeter the Great St.Petersburg Polytechnic UniversitySt.Petersburg 195251 Central Astronomical Observatory at Pulkovo of Russian Academy of Sciences St.Petersburg 196140

Thin organic films find expanding applications in electronic and optoelectronic devices, biotechnology,food packing, and for many other purposes. Among other factors, the stability of films with a thickness below a micrometer is determined by the zero-point and thermal fluctuations of the electromagnetic field. These fluctuations result in the van der Waals and Casimir free energy and forces between a film and a substrate. The fluctuationinduced force may be both attractive and repulsive making the film either more or less stable, respectively. Here, we review recently obtained results for the Casimir free energy of both freestanding and deposited on the metallic and dielectric substrates peptide films. We also perform computations for the free energy of the peptide films deposited on a silica glass substrate in the region of parameters where this free energy vanishes. Possible applications of the obtained results are discussed.

关键词： Casimir free energy organic electronics peptide film

Synchronous machine performance under geomagnetic disturbances

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High Voltage 2021年第5期6卷 894-903页

作者： Ilja Boguslawsky Nikolay Korovkin Victor Popov Olga Sokolova Peter the Great st.petersburg Polytechnic university St.PetersburgRussia Paul Scherrer Institute(PSI) VilligenSwitzerland

Geomagnetic disturbances(GMDs)are known to disturb power system equipment *** danger is associated with geomagnetically induced currents(GICs)occurring at the Earth's surface during *** do not endanger power system operation conditions by *** main challenge posed by GICs to power system states is the change in power system equipment operation conditions provoked by GIC *** primary avenue of blackout caused by GMDs is through power ***,in turn,can impair the operation of other power system equipment such as syn-chronous *** powerful synchronous machines are not designed and engineered to cope with the negative impacts of ***,the actual legal norms are inadequate in this *** the grid's resiliency to such an event is highly interesting to the *** physical processes in synchronous machine windings triggered by GICs and limitations brought to power grid operations are ***,the idea of the impact of GMDs on the power grid operation is *** analysis of the impact of GMDs on synchronous machines is performed in the second *** the end,the power system response under GMDs is studied.

关键词： geomagnetic Earth performance

BER Performance of Finite in Time Optimal FTN Signals for the Viterbi Algorithm

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Journal of Electronic Science and Technology 2020年第1期18卷 42-51页

作者： Sergey B.Makarov Ilya I.Lavrenyuk Anna S.Ovsyannikova Sergey V.Zavjalov Higher School of Applied Physics and Space Technologies Peter the Great St.Petersburg Polytechnic UniversitySt.Petersburg 195251

In this article, we consider the faster than Nyquist(FTN) technology in aspects of the application of the Viterbi algorithm(VA). Finite in time optimal FTN signals are used to provide a symbol rate higher than the "Nyquist barrier" without any encoding. These signals are obtained as the solutions of the corresponding optimization problem. Optimal signals are characterized by intersymbol interference(ISI). This fact leads to significant bit error rate(BER) performance degradation for "classical" forms of signals. However, ISI can be controlled by the restriction of the optimization problem. So we can use optimal signals in conditions of increased duration and an increased symbol rate without significant energy losses. The additional symbol rate increase leads to the increase of the reception algorithm complexity. We consider the application of VA for optimal FTN signals reception. The application of VA for receiving optimal FTN signals with increased duration provides close to the potential performance of BER,while the symbol rate is twice above the Nyquist limit.

关键词： Bit error rate(BER)performance faster than Nyquist(FTN) Nyquist limit optimal signals Viterbi algorithm(VA)

Characteristic plume morphologies of atmospheric Ar and He plasma jets excited by a pulsed microwave hairpin resonator

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Chinese Physics B 2018年第5期27卷 355-364页

作者： Zhao-Quan Chen Ben-Kuan Zhou Huang Zhang Ling-Li Hong Chang-Lin Zou Ping Li Wei-Dong Zhao Xiao-Dong Liu Olga stepanova A A Kudryavtsev School of Electrical&Information Engineering Anhui University of TechnologyMaanshan 243032China Faculty of Physics St.Petersburg State UniversitySt.Petersburg 198504Russia

Different discharge morphologies in atmospheric Ar and He plasmas are excited by using a pulsed microwave hairpin *** plasmas form an arched plasma plume at the opened end of the hairpin,whereas He plumes generate only a contracted plasmas in between both tips of metal *** this different point,their discharge processes have three similar characteristics:(i)the ionization occurs at the main electrode firstly and then develops to the slave electrode,(ii)during the shrinking stage the middle domain of the discharge channels disappears at last,and(iii)even at zero power input(in between pulses)a weak light region always exists in the discharge *** experimental results and electromagnetic simulations suggest that the discharge is resonantly excited by the local enhanced electric *** addition,Ar ionization and excitation energies are lower than those of He,the effect of Ar gas flow is far greater than that of He gas,and the contribution of accelerated electrons only locates at the domain with the strongest electric *** reasons could be used to interpret the different characteristic plume morphologies of the proposed atmospheric Ar and He plasmas.

关键词： atmospheric pressure plasma jet pulsed microwave discharge surface plasmon polaritons hairpin resonant discharge

Utilization of Extrinsic Fabry-Perot Interferometers with Spectral Interferometric Interrogation for Microdisplacement Measurement

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Journal of Electronic Science and Technology 2020年第1期18卷 59-75页

作者： Leonid Liokumovich Aleksandr Markvart Nikolai Ushakov Higher School of Applied Physics and Space Technologies Peter the Great St.Petersburg Polytechnic UniversitySt.Petersburg 195251

The paper presents a number of signal processing approaches for the spectral interferometric interrogation of extrinsic Fabry-Perot interferometers(EFPIs). The analysis of attainable microdisplacement resolution is performed and the analytical equations describing the dependence of resolution on parameters of the interrogation setup are derived. The efficiency of the proposed signal processing approaches and the validity of analytical derivations are supported by experiments. The proposed approaches allow the interrogation of up to four multiplexed sensors with attained resolution between 30 pm and 80 pm, up to three times improvement of microdisplacement resolution of a single sensor by means of using the reference interferometer and noisecompensating approach, and ability to register signals with frequencies up to 1 kHz in the case of 1 Hz spectrum acquisition rate. The proposed approaches can be used for various applications, including biomedical, industrial inspection, and others, amongst the microdisplacement measurement.

关键词： Absolute measurement dynamic measurement Fabry-Perot interferometer least-squares methods optical fiber sensors resolution analysis resolution enhancement sensor multiplexing spectral interferometry

Casimir Effect in Optoelectronic Devices Using Ferrofluids

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Journal of Electronic Science and Technology 2020年第1期18卷 76-82页

作者： Elena N.Velichko Galina L.Klimchitskaya Elina N.Nepomnyashchaya Institute of Physics Nanotechnology and TelecommunicationsPeter the Great St.Petersburg Polytechnic UniversitySt.Petersburg 195251 Department of Astrophysics Central Astronomical Observatoryat Pulkovo of the Russian Academy of SciencesSt.Petersburg 196140

Some of the modern electronic and optoelectronic devices exploit ferrofluids contained in narrow gaps between two material plates. When the width of the gap becomes below a micrometer, the boundary plates are subjected to the Casimir force arising from the zero-point and thermal fluctuations of the electromagnetic field. These forces should be taken into account in microdevices with the dimensions decreased to below a micrometer. In this paper, we review recently performed calculations of the attractive Casimir pressure in three-layer systems containing a ferrofluid. We also find the ferrofluidic system where the Casimir pressure is repulsive. This result is obtained in the framework of the fundamental Lifshitz theory of van der Waals and Casimir forces. The conclusion is made that enhanced repulsion due to the presence of a ferrofluid may prevent from sticking of closely spaced elements of a microdevice.

关键词： Casimir pressure ferrofluids microdevices repulsion

Ion-conducting Membranes Based on Bacterial Cellulose Nanofibers Modified by Poly(sodium acrylate-co-2-acrylamido-2-methylpropanesulfonic acid)

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Chinese Journal of Polymer Science 2024年第3期42卷 333-343,I0007页

作者： Elizaveta V.Batishcheva Nikolay N.Smirnov Natalya V.Bobrova Maria P.Sokolova Michael A.Smirnov Institute of Macromolecular Compounds Russian Academy of SciencesBolshoy pr.31Saint Petersburg 199004Russia

Green method for preparation of ion-conducting membranes(ICM) based on bacterial cellulose nanofibers(CNF) modified by a copolymer of sodium acrylate and 2-acrylamido-2-methylpropanesulfonic acid was elaborated. FTIR and NMR data confirmed grafting of polyacrylate onto cellulose surface. Formation of porous structure of the ICM was controlled by SEM and AFM. The maximal ionic conductivity of the membranes reaches 1.5 and 3.1 mS·cm^(-1)(60 ℃ and 98% relative humidity) when they are saturated with water or H_2SO_4(1 mol·L^(-1)) electrolyte,respectively. Prepared ICM was tested as a separator in a symmetrical supercapacitor with electrodes based on polyaniline hydrogel. The assembled cell demonstrate ability to operate at high current density up to 100 A·g^(-1) maintaining specific capacitance 165 F·g^(-1). Maximal specific capacitance of 289 F·g^(-1) was achieved at current density 1 A·g^(-1). Retaining of 90% of initial capacitance after 10000 of charge-discharge cycles proves high electrochemical stability of prepared ICM.

关键词： Bacterial cellulose Ion conductivity Porous membrane Supercapacitor

Self-healable and Robust Film Based on Electroactive Polymer Brush as Electrode for Flexible Supercapacitor

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Chinese Journal of Polymer Science 2024年第8期42卷 1049-1059页

作者： Maria P.Sokolova Vitaly K.Vorobiov Nikolay N.Smirnov Ivan S.Kuryndin Natalya V.Bobrova Michael A.Smirnov Institute of Macromolecular Compounds Russian Academy of SciencesBolshoy pr.31Saint Petersburg 199004Russia

The aim of this study was to develop self-healable and robust elect roconductive film based on polyaniline copolymer for application as electrode in flexible *** this purpose,the electroconductive polymer brushes(EPB)was *** synthesis of EPB is based on graft polymerizations of acrylamide(AAm)on poly(vinyl alcohol)(PVA)with formation of PVA-PAAm polymer brush and subsequent graft copolymerization of aniline and p-phenylenediamine on PVA-PAAm resulting in formation of EPB with electroconducting copoly(aniline-co-pphenylenediamine)(PAPh DA).It was found that the ratio between PVA and PAAm at the first stage greatly influence the electrochemical performance of the *** films were prepared by casting of EPB solution with subsequent *** of electrical current distribution through the film with AFM reveal more uniform distribution of PAPhDA in EPB in comparison with reference PVA-PAPhDA and PAAm-PAPhDA *** was demonstrated that mechanical cha racteristics and electrical conductivity values of films restore at large extent after curring and self-healing under optimal relative humidity level(58%).The flexile supercapacitor cell with EPB film electrodes demon strate specific capacitance 602 mF·cm^(-2)at the current density of 1 mA·cm^(-2)and retention 94%of initial capacitance after 5000 charge/discharge cycles.

关键词： Polymer brush Polyaniline Flexible supercapacitor Self-healing Electroconducting film

Influence of dust particles on spatial distributions of particles and fluxes in positive column of glow discharge

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Plasma Science and Technology 2019年第11期21卷 45-54页

作者： Ruihuan TIAN Chengxun YUAN Dmitrii V BOGDANOV Evgeniy A BOGDANOV Anatoly A KUDRYAVTSEV Zhongxiang ZHOU Department of Physics Harbin Institute of TechnologyHarbin 150001People’s Republic of China Faculty of Physics St.Petersburg State University198504St.PetersburgRussia

The research herein examined the results of numerical simulations of the positive column of a glow discharge in argon dusty plasma using COMSOL Multiphysics software under conditions similar to the project known as *** scenarios dealing with formations of spatial distributions of densities and fluxes for charged particles were studied,and evaluations of the influence of dust particles on the discharge were obtained in a wide range of dust *** extreme cases were distinguished:weak dust influence when the densities,fluxes and electric field profiles are not perturbed,and strong dust influence when all three density profiles(electrons,ions and charged dust)in the dust cloud are similar(parallel)to each other,resulting in all created charges in the dust cloud being lost inside the *** such a case,the ambipolar field and the transport of charged particles are decreased in the dust cloud,and any ambipolar flux is almost absent within the cloud.

关键词： dusty plasma glow discharge kinetics modeling scaling laws