检索结果-南通市图书馆

Analysis of the Caratheodory's Theorem on Dynamical System Trajectories Under Numerical Uncertainty

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2018年第4期5卷 787-793页

作者： pavel Osinenko Grigory Devadze Stefan Streif Automatic Control and System Dynamics Laboratory Technische Universitat Chemnitz09107 ChemnitzGermany IEEE

The current work proposes a new and constructive proof for the Caratheodory's theorem on existence and uniqueness of trajectories of dynamical systems. The key concern is the numerical uncertainty, i.e., the discrepancy between mathematical proofs, algorithms, and their implementations, which may affect the correct functioning of a control system. Due to growing demands on security and compliance with specifications,correctness of the control system functioning is becoming ever more important. Since in both dynamical systems and many control design approaches, one of the central notions is the system trajectory, it is important to address existence and uniqueness of system trajectories in a way which incorporates numerical uncertainty. Constructive analysis is a particular approach to formalizing numerical uncertainty and is used as the basis of the current work. The major difficulties of guaranteeing existence and uniqueness of system trajectories arise in the case of systems and controllers which possess discontinuities in time,since classical solutions to initial value problems do not *** issue is addressed in Caratheodory's theorem. A particular constructive variant of the theorem is proven which covers a large class of problems found in practice.

关键词： Constructive analysis Caratheodory’s theorem dynamical systems

Analytical and Numerical Modifications of Transonic Nozzle Flows

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2018年第4期27卷 382-388页

作者： Jiri STODULKA Helmut SOBIECZKY pavel SAFARIK CTU in Prague Faculty of Mechanical Engineering Dpt. of Fluid Dynamics and Thermodynamics TU Wien Institute of Technology

Classical transonic hodograph-based design methods are employed and revitalized using modern numerical tools to illustrate the design of a symmetrical accelerating-decelerating nozzle throat design. The concept of Elliptic Continuation is applied to solve transonic boundary value problems avoiding the inherently nonlinear nature of the basic equations and obtaining transonic flow examples using the Method of Characteristics in an inverse mode. Purpose of the present paper, besides describing a new special flow example, is to keep these classical methods alive for education of a new generation of creative engineers.

关键词：音速流动设计方法速度图非线性椭圆形工程师古典

Cas9-targeted Nanopore sequencing rapidly elucidates the transposition preferences and DNA methylation profiles of mobile elements in plants

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2023年第10期65卷 2242-2261页

作者： pavel Merkulov Sofya Gvaramiya Maxim Dudnikov Roman Komakhin Murad Omarov Alina Kocheshkova Zakhar Konstantinov Alexander Soloviev Gennady Karlov Mikhail Divashuk Ilya Kirov All‐Russia Research Institute of Agricultural Biotechnology Moscow 127550Russia Moscow Institute of Physics and Technology Dolgoprudny 141701Russia All‐Russia Center for Plant Quarantine Ramenski 140150Russia N.V.Tsitsin Main Botanical Garden of the Russian Academy of Sciences Moscow 127276Russia

Transposable element insertions(TEIs) are an important source of genomic innovation by contributing to plant adaptation, speciation, and the production of new varieties. The often large,complex plant genomes make identifying TEIs from short reads difficult and expensive. Moreover, rare somatic insertions that refect mobilome dynamics are difficult to track using short *** address these challenges, we combined Cas9-targeted Nanopore sequencing(CANS) with the novel pipeline Nano Cas TE to trace both genetically inherited and somatic TEIs in plants. We performed CANS of the EVADé(EVD) retrotransposon in wild-type Arabidopsis thaliana and rapidly obtained up to 40× sequence *** of hemizygous T-DNA insertion sites and genetically inherited insertions of the EVD transposon in the ddm1(decrease in DNA methylation1) genome uncovered the crucial role of DNA methylation in shaping EVD insertion *** also investigated somatic transposition events of the ONSEN transposon family, finding that genes that are downregulated during heat stress are preferentially targeted by ONSENs. Finally, we detected hypomethylation of novel somatic insertions for two ONSENs. CANS and Nano Cas TE are effective tools for detecting TEIs and exploring mobilome organization in plants in response to stress and in different genetic backgrounds, as well as screening T-DNA insertion mutants and transgenic plants.

关键词： Arabidopsis DNA methylation Nanopore sequencing transposon insertions

Ultra-high speed holographic shape and displacement measurements in the hearing sciences

在线全文

学校读者我要写书评

暂无评论

Light(Advanced Manufacturing) 2022年第2期3卷 1-14页

作者： Haimi Tang pavel Psota John J.Rosowski Cosme Furlong Jeffrey Tao Cheng Center for Holographic Studies and Laser micro-mechaTronics Worcester Polytechnic InstituteWorcesterMA USA01609 Mechanical Engineering Department Worcester Polytechnic InstituteWorcesterMA USA01609 Faculty of Mechatronics Informatics and Interdisciplinary StudiesTechnical University of LiberecLiberecCzech Republic46117 Eaton-Peabody Laboratory Massachusetts Eye and EarBostonMA USA02114 Department of Otolaryngology-Head and Neck Surgery Harvard Medical SchoolBostonMAUSA02115

The auditory system of mammals enables the perception of sound from our surrounding *** some of the smallest bones in the body,the ear transduces complex acoustic signals with high-temporal sensitivity to complex mechanical vibrations with magnitudes as small as tens of *** of the shape and acoustically induced motions of different components of the ear are essential if we are to expand our understanding of hearing mechanisms,and also provide quantitative information for the development of numerical ear models that can be used to improve hearing protection,clinical diagnosis,and repair of damaged or diseased *** are developing digital holographic methods and instrumentation using an ultra-high speed camera to measure shape and acoustically-induced motions in the middle *** we study the eardrum,the first structure of the middle ear which initializes the acoustic-mechanical transduction of sound for *** measurement system is capable of performing holographic measurement at rates up to 2.1 M frames per *** shape measurement modalities had previously been implemented into our holographic systems:(1)a multi-wavelength method with a wavelength tunable laser;and(2)a multi-angle illumination method with a single wavelength *** this paper,we present a third method using a miniaturized fringe projection system with a microelectromechanical system(MEMS)***,we optimize the processing of large data sets of holographic displacement measurements using a vectorized Pearson's correlation *** validate and compare the shape and displacement measurements of our methodologies using a National Institute of Standards and Technology(NIST)traceable gauge and sound-activated latex membranes and human eardrums.

关键词： Ultra-high speed digital holography Microelectromechanical systems(MEMS) Miniaturized Fringe Projection Middle-ear mechanics Shape and displacement measurements.

Definition of the Seismic Field of the Underground Sources in the Ambient Seismic Noise in the Tien Shan Region Using a Three-Component Gradient System

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 Earth Science 2020年第5期31卷 988-992页

作者： Anatoly Kuzmich Rybin Elena Anatol'evna Bataleva Kseniia Sergeevna Nepeina pavel Alexandrovich Kaznacheev pavel Alexandrovich Matiukov pavel Nikolaevich Aleksandrov Research Station of the Russian Academy of Sciences Bishkek 720049Kyrgyz Republic The Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences Moscow 123242Russia Geoelectromagnetic Research Center of the Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences Troitsk 108840Russia

This paper considers a new approach to solving the problem of quantitative estimation of the microseism energy for underground sources that is based on the synthesis of noise interferometry and the passive seismic method of the gradient system. The selection of a seismic field of the underground sources is considered in an experiment conducted in the Tien Shan region. The peculiarities of approach include the separation of vertical microseisms in the ambient seismic noise field structure according to the data of the seismic gradient system and a passive noise interferometry diagram, where microseisms from the underground sources are used as the seismic signal source. It is shown that the use of noise interferometry and passive seismic gradient system allows using the synchronous microseism recordings in a small number of points for passive medium sensing, and leads to the restoration of unknown energy parameters of the seismic field of underground sources.

关键词： gradient system passive seismic Tien Shan geodynamics

Leaf area index estimated by direct, semi-direct, and indirect methods in European beech and sycamore maple stands

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2020年第3期31卷 827-836页

作者： Jakub Cerny pavel Haninec Radek Pokorny The Forestry and Game Management Research Institute Research Station at OpocnoNa Olive 55051773 OpocnoCzech Republic The Department of Silviculture and Forest Establishment Faculty of Forestry and Wood TechnologyMendel UniversityZemedelska 361300 BrnoCzech Republic

Leaf area index(LAI)is one of the most important characteristics of forest stands that affects the fundamentals of tree physiological processes,biomass production,and mechanical *** LAI results obtained by the semi-direct and indirect methods(the needle technique and an LAI-2000 PCA)in three European beech(Fagus sylvatica L.)stands and one sycamore maple(Acer pseudoplatanus L.)stand were compared with LAI estimated by litter traps during the 2013 growing *** LAI was estimated using an LAI-2000 PCA which showed similar trends among the stands and strongly corresponded to phenological phases of deciduous stands in Europe,with the fastest rate of leaf area increment occurring during the first month following bud *** the growing season,maximum stand LAI value was on June 19th and reached 4.5–5.1,and 4.0 in the beech and maple stands,*** needle technique significantly underestimated(p05)LAI on average by 15.1%and 5.8%in the beech and maple stands,*** methods for LAI estimation at the stand level could be applicable in deciduous forest stands(beech,maple)with similar site and stand ***,calibration by direct method is necessary to obtain the required precision.

关键词： Leaf area index Specific leaf area Litter trap Needle technique LAI-2000 PCA

Analysis of the Water Film Behavior and its Breakup on Profile using Experimental and Numerical Methods

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2014年第4期23卷 325-331页

作者： Tomas MUZIK pavel SAFARIK Antonín TUCEK TechSoft Engineering Na Pankraci 2614000 PragueCzech Republic CTU in Prague Department of Fluid Dynamics and ThermodynamicsTechnicka 416607 PragueCzech Republic

This paper deals with the description of water film behaviour on the airfoil NACA0012 using experimental and numerical methods. Properties of the water film on the profile and its breakup into droplets behind the profile are investigated in the aerodynamic tunnel and using CFD methods. The characteristic parameters of the water film, like its thickness and shape for different flow modes are described. Hereafter are described droplets drifted by the air, which water film is broken behind the profile.

关键词：行为分析数值方法水膜实验计算流体力学方法空气动力学特征参数流量模式

Unveiling the nanotoxicological aspects of Se nanomaterials differing in size and morphology

在线全文

学校读者我要写书评

暂无评论

Bioactive Materials 2023年第2期20卷 489-500页

作者： Hana Stepankova Hana Michalkova Zbynek Splichal Lukas Richtera pavel Svec Tomas Vaculovic Jan Pribyl Martin Kormunda Simona Rex Vojtech Adam Zbynek Heger Department of Chemistry and Biochemistry Mendel University in BrnoZemedelska 1BrnoCZ-61300Czech Republic Central European Institute of Technology Brno University of TechnologyPurkynova 123BrnoCZ-61200Czech Republic Department of Chemistry Masaryk UniversityKamenice 5BrnoCZ-62500Czech Republic Institute of Laboratory Research on Geomaterials Faculty of Natural SciencesComenius University in BratislavaMlynska dolinaIlkovicova 684215 BratislavaSlovak Republic Central European Institute of Technology Masaryk UniversityKamenice 5BrnoCZ-62500Czech Republic Department of Physics Faculty of ScienceJ.E.Purkyne UniversityPasteurova 1Usti nad LabemCZ-40096Czech Republic

Although the general concept of nanotechnology relies on exploitation of size-dependent properties of nanoscaled materials,the relation between the size/morphology of nanoparticles with their biological activity remains not well ***,we aimed at investigating the biological activity of Se nanoparticles,one of the most promising candidates of nanomaterials for biomedicine,possessing the same crystal structure,but differing in morphology(nanorods *** particles)and aspect ratios(AR,11.5 vs.22.3 vs.1.0)in human cells and BALB/c ***,we report that in case of nanorod-shaped Se nanomaterials,AR is a critical factor describing their cytotoxicity and ***,spherical nanoparticles(AR 1.0)do not fit this statement and exhibit markedly higher cytotoxicity than lower-AR Se *** of cytotoxicity,we also show that morphology and size substantially affect the uptake and intracellular fate of Se *** line with in vitro data,in vivo *** of Se nanomaterials revealed the highest toxicity for higher-AR nanorods followed by spherical nanoparticles and lower-AR ***,we revealed that Se nanomaterials are able to alter intracellular redox homeostasis,and affect the acidic intracellular vesicles and cytoskeletal architecture in a size-and morphology-dependent *** the tested nanoparticles were produced from the similar sources,their behavior differs markedly,since each type is promising for several various application scenarios,and the presented testing protocol could serve as a concept standardizing the biological relevance of the size and morphology of the various types of nanomaterials and nanoparticles.

关键词： Aspect ratio Biocompatibility Nanotoxicology Nanorods

Coalification and coal alteration under mild thermal conditions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Coal Science & Technology 2018年第3期5卷 358-373页

作者： pavel Straka Ivana Sykorova Institute of Rock Structure and Mechanics v.v.i The Czech Academy of Sciences V Holegovickach 41 18209 Prague 8Czech Republic

Coalification temperatures are often considered to be approximately 100–170 °C for bituminous coal and 170–275 °C for anthracite. However, our micropetrographic observations, solid state 27Al magic-angle spinning nuclear magnetic resonance measurements, interpretation of δ13C values for whewellite in pelosiderite concretions from Carboniferous sediments, and assessment of whewellite thermal stability show that coalification temperatures can be significantly lower. Also the temperatures of coal alteration may be substantially lower than is stated. Ordinarily, high-temperature alteration is reported, but microthermometric measurements of fluids temperatures and micropetrographic observations show that the coal alteration can take place at low temperatures. For this reason, coals from the Kladno–Rakovník Basin, part of Late Paleozoic continental basins of the Czech Republic, were analyzed. Regarding coalification, micropetrographic characterizations of unaltered coals, the presence of thermally unstable Al complexes in the coal organic mass documented using 27Al MAS NMR method, and proven occurrence of whewellite in pelosiderite concretions suggest a lower coalification temperature, max. ~ 70 °C. Regarding coal alteration, micropetrographic observations revealed (a) the weaker intensity of fluorescence of liptinite, (b) mylonitic structures and microbreccia with carbonate fluid penetration, and (c) high oxygen content in coals (37–38 wt.%). These phenomena are typical for thermal and oxidative alteration of coal. As the temperature of carbonate fluids inferred from fluid inclusion analysis was evaluated as ~ 100–113 °C, the temperature of coal alteration was suggested as ~ 113 °C; the alteration was caused by hot hydrothermal fluids.

关键词：煤化温度改变液体温度热稳定性质量记录碳酸盐低温度古生代