检索结果-南通市图书馆

An approach to net-centric control automation of technological processes within indust.ial IoT syst.ms

在线全文

学校读者我要写书评

暂无评论

Advances in Manufacturing 2017年第4期5卷 388-393页

作者： Nikita Voinov Igor Chernorutsky Pavel Drobintsev Vsevolod Kotlyarov Inst.tute of Computer Science and Technology Peter the Great St. Petersburg Polytechnic UniversityPolytechnicheskaya 29 Saint Petersburg Russia 195251

The use of indust.ial internet networks with net- centric control is the driving trend behind the future material manufacturing of goods and services. The promising future of this approach is provided by these complex net-centric syst.ms functioning with high relia- bility. The problem of intelligent net-centric control and reliable network functioning is fundamental, with the additional requirement that the syst.m should preserve st.keholder security and privacy according to policies. The issue is that such syst.ms are characterized by complex multi-parameter operability modes controlled by various criteria. This st.dy considers an approach to providing reliable management of complicated Internet of things （IoT） syst.ms. This is achieved by solving multi-criteria tasks over many processes of various physical natures. Corresponding methods of hierarchical decomposition of multi-criteria tasks, process levels of multi-criteria opti- mization, specifics of aggregation levels, and the mast.r equation of the optimization process are described.

关键词： Net-centric control Technological process Internet of things (IoT) Reliability Multi-criteria optimization

Using isotope methods to st.dy alpine headwater regions in the Northern Caucasus and Tien Shan

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Earth Science 2017年第3期11卷 531-543页

作者： E. RETS J. CHIZHOVA N. LOSHAKOVA I. TOKAREV M. KIREEVA N. BUDANTSEV Yu.K. VASILCHUK N. FROLOVA V. POPOVNIN P. TOROPOV E. TERSKAYA A. SMIRNOV E. BELOZEROV M. KARASHOVA Water Problems Inst.tute Russian Academy of Sciences ul. Gubkina 3 Moscow 119333 Russia Faculty of Geography Lomonosov Moscow State University Moscow 119991 Russia Center for Geo-Environmental Research and Modelling (GEOMODEL) at st. petersburg university St. Petersburg 198504 Russia

High mountain areas provide water resources for a large share of the world＇s population. The ongoing deglaciation of these areas is resulting in great inst.bility of mountainous headwater regions, which could significantly affect water supply and intensify dangerous hydrological processes. The hydrological processes in mountains are st.ll poorly underst.od due to the complexity of the natural conditions, great spatial variation and a lack of observation. A knowledge of flow-forming processes in alpine areas is essential to predict future possible trends in hydrological conditions and to calculate river runoff characterist.cs. The goal of this st.dy is to gain detailed field data on various components of natural hydrological processes in the alpine areas of the North Caucasus and Central Tien Shan, and to invest.gate the possibility that the isotopic method can reveal important regularities of river flow formation in these regions. The st.dy is based on field observations in representative alpine river basins in the North Caucasus （the Dzhankuat river basin） and the Central Tien Shan （the Chon-Kyzyl-Suu river basin） during 2013-2015. A mixing-model approach was used to conduct river hydrograph separation. Isotope methods were used to est.mate the contribution of different nourishment sources in total runoff and its regime. ~80, ~D and mineralization were used as indicators. Two equation syst.ms for the st.dy sites were derived： in terms of water routing and runoff genesis. The Dzhankuat and Chon-Kyzyl-Suu river hydrographs were separated into 4 components： liquid precipitation/meltwaters, surface routed/subsurface routed waters.

关键词： isotope methods mountain hydrology hydro-graph separation Dzhankuat river Chon-Kyzyl-Suu river,field data

Empirical-st.tist.cal Methodology and Methods for Modeling and Forecast.ng of Climate Variability of Different Temporal Scales

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2001年第5期18卷 844-863页

作者： Vladimir A. Lobanov state Hydrological Inst.tute, A MFONP, st. petersburg, Russia LASG, Inst.tute of Atmospheric Physics, Beijing 100029. state Hydrological Inst.tute AM FONP St. Petersburg Russia LASG Institute of Atmospheric Physics Beijing China

Main problem of modern climatology is to assess the present as well as future climate change, For this aim two approaches are used: physic-mathematic modeling on the basis of GCMs and palaeoclimatic analogues. The third approach is based on the empirical-st.tist.cal methodology and is developed in this paper. This approach allows to decide two main problems: to give a real assessment of climate changes by observed data for climate monitoring and extrapolation of obtained climate tendencies to the nearest.future (10-15 years) and give the empirical basis for further development of physic-mathematical models. The basic theory and methodology of empirical-st.tist.c approach have been developed as well as a common model for description of space-time climate variations taking into account the processes of different time scales. The way of decreasing of the present and future uncertainty is suggest.d as the extraction of long-term climate changes components in the particular time series and spatial generalization of the same climate tendencies in the obtained homogeneous regions. Algorithm and methods for realization of empirical-st.tist.c methodology have been developed along with methods for generalization of intraannual fluctuations, methods for extraction of homogeneous components of different time scales (interannual, decadal, century), methodology and methods for spatial generalization and modeling, methods for extrapolation on the basis of two main kinds of time models: st.chast.c and determinist.c-st.chast.c. Some applications of developed methodology and methods are given for the longest.time series of temperature and precipitation over the world and for spatial generalization over the European area.

关键词： climate change climate variability empirical-st.tist.cal approach spatial-temporal modeling inhomogeneous non-st.tionary

Topology of triple-point metals

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2019年第7期28卷 54-72页

作者： Georg W.Winkler Sobhit Singh Alexey A.Soluyanov Microsoft Quantum Microsoft Station Q University of California Santa Barbara California 93106-6105 USA Department of Physics and Ast.onomy Rutgers University Piscutuwny New Jersey 08854 USA Inst.tute of Physics University of Zurich. Winterthurerstrasse 190 8057 Zurich Switzerland Department of Physics. st. petersburg state university St. Petersburg 199034Russia

We discuss and illust.ate the appearance of topological fermions and bosons in triple-point metals where a band crossing of three electronic bands occurs close to the Fermi *** bosons appear in the phonon spectrum of certain triple-point metals, depending on the mass of atoms that form the binary triple-point *** first.provide a classification of possible triple-point electronic topological phases possible in cryst.lline compounds and discuss the consequences of these topological phases, seen in Fermi arcs, topological Lifshitz transitions, and transport *** we show how the topological phase of phonon modes can be extracted and proven for relevant ***,we show how the interplay of electronic and phononic topologies in triple-point metals puts these metallic materials into the list.of the most.efficient metallic thermoelectrics known to date.

关键词： topological metals topological phonons electronic st.ucture thermoelectrics

Composite Biomaterials Based on Poly(L-Lactic Acid)and Functionalized Cellulose Nanocryst.ls

在线全文

学校读者我要写书评

暂无评论

Journal of Renewable Materials 2020年第4期8卷 383-395页

作者： Mariia st.panova Ilia Averianov Olga Solomakha Natalia Zabolotnykh Iosif Gofman Mikhail Serdobintsev Tatiana Vinogradova Viktor Korzhikov-Vlakh Evgenia Korzhikova-Vlakh Inst.tute of Macromolecular Compounds Russian Academy of SciencesSt.Petersburg199004Russia st.petersburg Research Inst.tute of Phthisiopulmonology St.Petersburg194064Russia Inst.tute of Chemist.y Saint-Petersburg State UniversitySt.Petersburg199034Russia

The biocomposite films were prepared from poly(L-lactic acid)and cellulose *** improve interfacial compatibility of hydrophilic cellulose nanocryst.ls with hydrophobic matrix polymer as well as to provide the ost.oconductive properties,cellulose was functionalized with poly(glutamic acid).The modified cellulose nanocryst.ls were better dist.ibuted and less aggregated within the matrix,which was test.fied by scanning electron,optical and polarized light *** to mechanical test.,composites filled with nanocryst.ls modified with PGlu demonst.ated higher values of Young’s modulus,elongation at break and tensile *** of composite materials in model buffer solutions for 30 weeks followed with st.ining of Ca^(2+)deposits with Alizarin Red S assay test.fied better mineralization of materials containing PGlu-modified cellulose nanocryst.ls as *** the result of in vivo experiment,the developed composite materials showed less level of inflammation in comparison with pure polymer matrix and composites filled with non-functionalized cellulose nanocryst.ls.

关键词： Biomaterials polymer composites biodegradable and biocompatible polymers poly(L-lactic acid) cellulose nanocryst.ls modification

Simulating bicycle traffic by the intelligent-driver model-Reproducing the traffic-wave characterist.cs observed in a bicycle-following experiment

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Traffic and transportation Engineering(English Edition) 2020年第1期7卷 19-29页

作者： Valentina Kurtc Martin Treiber Inst.tute of Applied Mathematics and Mechanics Peter the Great St.Petersburg Polytechnic UniversitySt.Petersburg 195251Russia Inst.tute for transport and Economics Technische Universitat DresdenDresden 01062Germany

Bicycle traffic operations become increasingly important and yet are largely ignored in the traffic flow community,until *** hypothesize that there is no qualitative difference between vehicular and bicycle traffic flow dynamics in single-file case,so the latter can be described by reparameterized car-following *** test.this proposition,we reproduce German(Andresen et al.,2014)and Chinese(Jiang et al.,2016)bicycle experiments on a ring with the intelligent-driver model(IDM)and compare its fit quality(calibration)and predictive power(validation)with that of the necessary-deceleration-model(NDM),which is specifically designed for bike *** find similar quality metrics for both models,so the above hypothesis of a qualitative equivalence cannot be ***,calibration errors of the IDM turn up to be slightly smaller compared to the NDM *** NDM represents significant calibration errors for high flow densities,which correspond to flow states,when st.p-and-go wave *** to validation test.,the IDM outperforms the NDM as *** two types of validation techniques we discover that inter-driver variation is much higher than the intra-driver variation for bicycle *** coincides with the results obtained from vehicular traffic experiments(NGSIM trajectory data).In addition,we suggest.the measure for quantitative comparison of two microscopic fundamental diagrams,which are derived from experimental data and simulated *** analysis of speed-density relations provides more or less the same results for both models.

关键词： Bicycle traffic Car-following model st.p-and-go waves Calibration Validation Fundamental diagram

Meta-optics and bound states in the continuum

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2019年第12期64卷 836-842页

作者： Kirill Koshelev Andrey Bogdanov Yuri Kivshar Nonlinear Physics Centre Australian National UniversityCanberra ACT 2601Australia ITMO university St. Petersburg 197101Russia

We discuss the recent advances in meta-optics and nanophotonics associated with the physics of bound states in the continuum(BICs). Such resonant states appear due to a st.ong coupling between leaky modes in optical guiding st.uctures being supported by subwavelength high-index dielectric Mieresonant nanoantennas or all-dielectric metasurfaces. First. we review briefly very recent developments in the BIC physics in application to isolated subwavelength particles. We pay a special attention to novel opportunities for nonlinear nanophotonics due to the large field enhancement inside the particle volume creating the resonant states with high-quality(high-Q) factors, the so-called quasi-BIC, that can be supported by the subwavelength particles. Second, we discuss novel applications of the BIC physics to alldielectric optical metasurfaces with broken-symmetry meta-atoms when tuning to the BIC conditions allows to enhance subst.ntially the Q factor of the flat-optics dielectric st.uctures. We also present the original results on nonlinear high-Q metasurfaces and predict that the frequency conversion efficiency can be boost.d dramatically by smart engineering of the asymmetry parameter of dielectric metasurfaces in the vicinity of the quasi-BIC regime.

关键词： Bound states in the continuum Meta-optics Second-harmonic generation Nanoresonator Metasurfaces

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

在线全文

学校读者我要写书评

暂无评论

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 st.panova 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 characterist.cs:(i)the ionization occurs at the main electrode first.y and then develops to the slave electrode,(ii)during the shrinking st.ge 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 exist. 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 st.ongest.electric *** reasons could be used to interpret the different characterist.c 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

First.results of turbulence invest.gation on Globus-M2 using radial correlation Doppler reflectometry

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2024年第10期26卷 49-55页

作者： A.PONOMARENKO A.YASHIN V.GUSEV E.KISELEV G.KURSKIEV V.MINAEV Y.PETROV N.SAKHAROV P.SHCHEGOLEV E.TKACHENKO N.ZHILTSOV Peter the Great st.petersburg Polytechnic university St.Petersburg 195251Russia Ioffe Inst.tute St.Petersburg 194064Russia

The first.results of invest.gation of the turbulence st.ucture using Doppler backscattering(DBS)on the Globus-M2 tokamak are presented.A one-channel DBS syst.m with a variable probing frequency within the 18–26 GHz range was inst.lled to invest.gate the edge plasma at normalized minor radiiρ=0.9–*** correlation Doppler reflectometry was used to st.dy the changes in turbulence eddies after the LH *** analysis was applied to the phase derivative of complex in-phase and quadrature(IQ)signals of the DBS diagnost.c as it contains information about the poloidal plasma rotation *** L-mode,the radial correlation length L_(r)is est.mated to be 3 cm and after transition to H-mode reduces to approximately 2 *** modelling in a linear local approximation using code GENE indicates that the inst.bility with positive growth rate at the normalized minor radiusρ=0.75 in L-mode and H-mode on Globus-M2 was the ion temperature gradient(ITG)mode.

关键词： tokamak turbulence Doppler backscattering correlation reflectometry