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American Journal of Analytical Chemistry 2013年第3期4卷 125-133页

作者： Jan Prech Václav Matousek JiriVáclavik Jan Pechacek Kamila Syslova Petr Sot jakub januscak Beáta Vilhanová Marek Kuzma Jaromir Toman Petr Kacer Department of Organic Technology Institute of Chemical TechnologyPragueCzech Republic Laboratory of Molecular Structure Characterization Institute of MicrobiologyAcademy of Sciences of the Czech RepublicPragueCzech Republic

A method for the analysis of the optical purity of a series of chiral substituted tetrahydroisoquinolines (THIQs) was developed. The method is based on pre-column derivatization of the analytes with the derivatization reagent (–)-(1R)-menthyl chloroformate. The derivatization reaction selectively gives diastereomeric carbamates that are resolvable on an achiral non-polar GC column. The developed technique covers variously substituted THIQs, which differ significantly in volatility, steric and electronic properties. In all cases, the resolution factors (R) exceeded the value of 1.5. The method represents a robust way of analysis of mixtures of THIQs, which are often present in various matrixes such as body fluids, tissues and reaction mixtures.

关键词： Tetrahydroisoquinolines Enantiomeric Composition Derivatization Menthyl Chloroformate Gas Chromatography

Mechanisms behind elevated serum levels of plasminogen activator inhibitor-1 in frontotemporal lobar degeneration

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Neural Regeneration Research 2025年第8期20卷 2317-2318页

作者： Francesco Angelucci jakub Hort Memory Clinic Department of NeurologySecond Faculty of MedicineCharles University and Motol University HospitalPragueCzech Republic International Clinical Research Centre St.Anne’s University HospitalBrnoCzech Republic

Frontotemporal lobar degeneration(FTLD)is a form of progressive dementia characterized by degeneration of the frontal and temporal lobes of the *** pathology involves a series of cognitive,behavioral,and neurological ... 详细信息

关键词： degeneration elevated pathology

Patterns of Ips cembrae(Herr)infestation on trap and standing trees of European larch(Larix decidua Mill.)

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Journal of Forestry Research 2023年第6期34卷 2041-2050页

作者： jakub Špoula Emanuel Kula Faculty of Forestry and Wood Technology Department of Forest Protection and Wildlife ManagementMendel University in BrnoZemědělská3Brno 61300Czech Republic

The large larch beetle,Ips cembrae,is a significant pest causing the death of *** 2020,the attack density of *** on larch trap trees and standing trees was evaluated using sample sections placed along the *** a defensive measure against ***,trap trees were highly effective in both spring and *** attack density increased with increasing trap tree surface area/*** were established evenly throughout the entire trunk including the thin upper *** the number of trap trees was low and their capacity full,a continual aggregation of adults occurred due to pheromone communication,leading to attacks on healthy standing trees in the immediate *** was found that *** attacked standing trees from the trunk base,with a continual colonization of the stem up to 70%of the tree height in a time-differentiated progression of development *** attack density of *** on standing trees was up to 40%lower than on the trap trees.

关键词： Forest protection Ips cembrae Larix decidua Stem infestation Trap tree

Multilayer microhydraulic actuators with speed and force configurations

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Microsystems & Nanoengineering 2021年第2期7卷 97-106页

作者： jakub Kedzierski Hero Chea Massachusetts Institute of Technology Lincoln Laboratory LexingtonMA02420USA

Electrostatic motors have traditionally required high voltage and provided low torque, leaving them with a vanishingly small portion of the motor application space. The lack of robust electrostatic motors is of particular concern in microsystems because inductive motors do not scale well to small dimensions. Often, microsystem designers have to choose from a host of imperfect actuation solutions, leading to high voltage requirements or low efficiency and thus straining the power budget of the entire system. In this work, we describe a scalable three-dimensional actuator technology that is based on the stacking of thin microhydraulic layers. This technology offers an actuation solution at 50 volts, with high force, high efficiency, fine stepping precision, layering, low abrasion, and resistance to pull-in instability. Actuator layers can also be stacked in different configurations trading off speed for force, and the actuator improves quadratically in power density when its internal dimensions are scaled-down.

关键词： configuration trading inductive

The Merits of Passive Compliant Joints in Legged Locomotion： Fast Learning, Superior Energy Efficiency and Versatile Sensing in a Quadruped Robot

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Journal of Bionic Engineering 2017年第1期14卷 1-14页

作者： Matej Hoffmann jakub Simanek iCub Facility Istituto Italiano di Tecnologia Genova 16123 Italy Artificial Intelligence Laboratory Department of lnformatics University of Zurich Zurich 8050 Switzerland Department of Measurement Faculty of Electrical Engineering Czech Technical University in Prague Prague 166 27 Czech Republic

A quadruped robot with four actuated hip joints and four passive highly compliant knee joints is used to demonstrate the potential of underactuation from two standpoints： learning locomotion and perception. First, we show that：（i） forward locomotion on flat ground can be learned rapidly （minutes of optimization time）; （ii） a simulation study reveals that a passive knee configuration leads to faster, more stable, and more efficient locomotion than a variant of the robot with active knees; （iii） the robot is capable of learning turning gaits as well. The merits of underactuation （reduced controller complexity, weight, and energy consumption） are thus preserved without compromising the versatility of behavior. Direct optimization on the reduced space of active joints leads to effective learning of model-free controllers. Second, we find passive compliant joints with po- tentiometers to effectively complement inertial sensors in a velocity estimation task and to outperform inertial and pressure sensors in a terrain detection task. Encoders on passive compliant joints thus constitute a cheap and compact but powerful sensing device that gauges joint position and force/torque, and -- if mounted more distally than the last actuated joints in a legged robot -- it delivers valuable information about the interaction of the robot with the ground.

关键词： legged robots underactuated robots compliant joints learning locomotion force and tactile sensing haptic terrain classification

Evaluation of overhead line current unbalance in meshed grids and its reduction

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Journal of Modern Power Systems and Clean Energy 2018年第6期6卷 1204-1212页

作者： jakub EHRENBERGER Jan ?VEC Department of Electrical Power Engineering Czech Technical University in Prague

This paper describes new methodology in the current unbalance calculations in meshed grids. The meshed grids, mainly the transmission ones, consist of more parts connected together which are formed using different conductor types, phase sequence arrangements,tower constructions, and various number of lines on the same tower. Therefore several computational challenges arise in comparison with the widely discussed point-topoint configuration. The methodology divides the grid into a number of impedance matrices respecting all the self and mutual impedances among all conductors and all parallel lines. Another challenging issue for the line impedancedescription is changing the number of shield wires along the line if the line is composed of several sections with different tower configurations. For the current unbalance calculation, shield wires must also be included in the algorithms, and matrices of various dimensions can be obtained. For the overall matrix description to be used,dimensions of all matrices in final equations must be equal,and therefore the virtual shield wires are created. To compare more conductor transposition cases with each other, the line loadings caused by voltage sources should be equal. This is necessary mainly in case of meshed grids where the supplying sources on different lines can have strong mutual couplings. This can be achieved by an appropriately designed optimization of the connected voltage sources.

关键词： Current unbalance Phase sequence arrangement Shield wire Unbalance factor Zero-sequence set

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Dynamics of Wicking

Journal of Donghua University(English Edition) 2002年第3期19卷 77-79页

作者： jakub Wiener Tech. Univ. of Liberec Czech Republic

An exponential model is proposed for the description of wicking, which is suitable for describing the whole process of wicking. Results are discussed and verified by the experimental data. Exponential model can be use... 详细信息

关键词： wicking process, capillary, wicking dynamics.

Hybrid aqueous capacitors with improved energy/power performance

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Progress in Natural Science:Materials International 2015年第6期25卷 642-649页

作者： jakub Menzel Krzysztof Fic Elzbieta Frackowiak Poznan University of Technology Institute of Chemistry and Technical Electrochemistry

This work reports on a high-voltage,hybrid capacitor involving two separate redox *** solutions of Mg(NO3)2and KI have been used for negative and positive electrode,*** p H ? 2 for electrode( t) with KI solution and modifying Mg(NO3)2solution to p H ? 9 for negative side play a crucial role for a stable long-term operation of capacitor at enhanced voltage.A benefit from such a construction is a pseudocapacitive contribution from hydrogen sorption reaction on the negative electrode and high iodine/iodide activity on the positive electrode,enhancing the energy with no remarkable impact on the power *** solution allows a high voltage(1.8 V) to be reached and thereby high power and energy performance( 20 W h/kg at 1 k W/kg) to be *** long-term stability has been confirmed by floating and galvanostatic tests.

关键词： Electrochemical capacitors High-voltage systems Hybrid systems Carbon electrodes Aqueous systems Neutral electrolytes

Surface Modification of Poly Vinyl Chloride (PVC) Using Low Pressure Argon and Oxygen Plasma

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Plasma Science and Technology 2010年第2期12卷 204-207页

作者： Mahmood GHORANNEVISS Sheila SHAHIDI jakub WIENER Plasma Physics Research Center Science and Research Branch Islamic Azad University Department of Textile Chemistry Faculty of Textile Technical University of Liberec

In this study, commercial poly vinyl chloride （PVC） films were treated by oxygen and argon plasmas in a cylindrical glass tube which was surrounded by a DC variable magnetic field, with different sample positions in the plasma reactor and also different exposure durations. Effects of the plasma treatment on the hydrophilic properties of the films were studied by mea- suring the water drop contact angle on the surface of the samples. The surface topography of the untreated and plasma treated films was analyzed and compared by atomic force microscopy （AFM）. The optical characteristic changes in treated samples were investigated using reflective spectrophotometry. Also, the chemical changes which appeared on the surface of the samples were investigated using Fourier transform infrared spectroscopy （FTIR）. The results show that the plasma treated PVC becomes more hydrophilic with an enhanced wettability. A sharp de- crease in the water contact angle may also be a consequence of the surface texturization. The aging effect on wettability of the samples was also investigated. The results show that the effect of oxygen plasma on the surface properties of the samples is more pronounced compared with that of argon plasma.

关键词： plasma surface modification poly vinyl chloride

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

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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