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Field-emission electron gun for a MEMS electron microscope

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Microsystems & Nanoengineering 2021年第3期7卷 139-147页

作者： michal Krysztof Department of Microsystems Faculty of Microsystem Electronics and PhotonicsWroclaw University of Science and Technologyul.Z.Janiszewskiego 11/1750-372 WroclawPoland

This article presents a field-emission electron gun in tended for use in a MEMS(microelectromechanical system)electron *** fabricati on process follows the tech no logy of a miniature device under development built from silicon electrodes and glass *** electron gun contains a silicon cathode with a single very sharp protrusion and a bundle of disordered CNTs deposited on its end(called a sharp silicon/CNT cathode).It was tested in diode and triode con *** the diode con figuration,a low threshold voltage<1000V and a high emission current that reached 90 pA were *** 30 min of operation at 900 V,the emission current decreased to 1.6 pA and was stable for at least 40 min,with RMS fluctuation in the anode current lower than 10%.The electron beam spot of the source was observed on the phosphor *** the diode configuration,the spot size was the same as the emission area(~10 pm)z which is a satisfactory *** the triode configuration,an extraction electrode(gate)control function was *** gate limited the emission current and elongated the lifetime of the gun when the current limit was ***,the electron beam current fluctuations at the anode could be reduced to〜1%by using a feedback loop circuit that controls the gate voltage,regulating the anode *** developed sharp silicon/CNT cathodes were used to test the MEMS electron source demonstrator,a key component of the MEMS electron microscope,operating under atmospheric pressure *** of the phosphor layer(ZnS:Ag)deposited on the thin silicon nitride membrane(anode)was observed.

关键词： sharp figuration lifetime

Understanding the evolution of learning by explicitly modeling learning mechanisms

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Current Zoology 2015年第2期61卷 341-349页

作者： michal ARBILLY Department of Psychology University of California Berkeley CA 94720 USA

Models of the evolution of learning often assume that learning leads to the best solution to any task, and disregard the details of the learning and decision-making process along with its potential pitfalls. These models therefore do not explain in- stances in the animal behavior literature in which learning leads to maladaptive behaviors. In recent years a growing number of theoretical studies use explicit models of learning mechanisms, offering a fresh perspective on the issue by revealing the dynam- ics of information acquisition and biases arising from it. These models have pointed out possible learning rules and their adaptive value, and shown that the value of learning may crucially depend on such factors as the layout of the physical environment to be learned, the structure of the payoffs offered by different alternatives, the risk of failure, characteristics of the learner and social interactions. This review considers the merits of explicit modeling in studying the evolution of learning, describes the kinds of results that can only be obtained from this modeling approach, and outlines directions for future research .

关键词： Agent-based simulation Learning bias Learning rule Decision rule Cognition

Comparison of three methods for natural gas dehydration

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Journal of Natural Gas Chemistry 2011年第5期20卷 471-476页

作者： michal Netusil Pavel Ditl Department of Process Engineering Czech Technical University

This paper compares three methods for natural gas dehydration that are widely applied in industry：（1） absorption by triethylene glycol, （2） adsorption on solid desiccants and （3） condensation. A comparison is made according to their energy demand and suitability for use. The energy calculations are performed on a model where 105 Nm3/h water saturated natural gas is processed at 30 °C. The pressure of the gas varies from 7 to 20 MPa. The required outlet concentration of water in natural gas is equivalent to the dew point temperature of -10 °C at gas pressure of 4 MPa.

关键词： gas reservoir underground gas storage natural gas gas dehydration

Limited acid deposition inferred from diatoms during the 20th century--A case study from lakes in the Tatra Mountains

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Journal of Environmental Sciences 2018年第2期30卷 92-106页

作者： Elwira Sienkiewicz michal Gasiorowski Institute of Geological Sciences Polish Academy of Sciences Research Centre at Warsaw St. Twarda SI/SS Warsaw PL-00818 Poland

Mountain lakes are usually sensitive to the effects of global and regional environmental changes. Since the second half of the 20 th century, surface-water acidification has become a significant ecological problem, and many lakes in Europe and North America have anthropogenically acidified. Additionally, following reduction in emissions of sulfur（S） and nitrogen（N） compounds, recovery from acidification has been observed in many lakes. In this study, we used changes in diatom communities to reconstruct the p H histories based on changes recorded in nine Tatra lakes（Western Carpathians, Poland） since approximately1850 AD. Overall, results indicate that acidic precipitation had little influence on lake-water p H in the Tatra Mountain lakes. Changes in diatom-inferred p H（DI-p H） generally were small and showed little evidence of acidification during the time of the highest air pollution（since the 1960 s）, and have shown little change since the reduction of acidic deposition since the 1990 s. Lakes that showed some evidence of acidification included dystrophic lakes with low acid neutralizing capacity. However, as illustrated by the PCA trajectories of the diatom assemblages, the majority of the lakes currently contain diatom assemblages that are unlike the diatom floras that existed ca. 1850.

关键词： Lake Palaeolimnology Environmental impact assessment Algae Acidification Pollution

Proteomic-based evidence for adult neurogenesis in birds and mammals as indicated from cerebrospinal fluid

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Neural Regeneration Research 2022年第12期17卷 2576-2581页

作者： Eleni Voukali michal Vinkler Department of Zoology Faculty of ScienceCharles UniversityPragueCzech Republic

Adult neurogenesis is the life-long process of neural stem cell proliferation,differentiation into neurons,migration,and incorporation into the existing neuronal *** decades of research,it is now widely accepted that mammals and birds retain the capacity to regenerate neurons even after their subadult *** fluid participates in the regulation of the neurogenic niches of the vertebrate brain through signaling pathways not fully *** studies of cerebrospinal fluid have the potential to allow the in-depth characterization of its molecular *** studies help to delineate those pathways that are universally critical for the regulation of neurogenesis in *** this review,we performed literature-based data mining in studies using liquid chromatography-tandem mass spectroscopy that analyzed cerebrospinal fluid samples from healthy adult humans(Homo sapiens);mice(Mus musculus);sheep(Ovis aries);chickens(Gallus gallus);and two parrot species,the budgerigar(Melopsittacus undulatus)and cockatiel(Nymphicus hollandicus).We identified up to 911 proteins represented in cerebrospinal fluid,involved in various pathways regulating adult ***,only 196 proteins were common across humans,mice,and *** components involved in nervous system development,cell migration,and axonal guidance were commonly evident in all species investigated so *** bioinformatic analysis revealed that the universally over-represented pathways involved L1 cell adhesion molecule protein interactions,cell-adhesion molecules,signals regulating extracellular matrix remodeling,regulation of insulin growth factor signaling,axonal guidance,programmed cell death,immune signaling,and post-translational *** of the reported proteins are part of extracellular vesicles enriched in cerebrospinal ***,the information presently available is still highly fragmentary,and far more questions persist than

关键词： adult neurogenesis birds cerebrospinal fluid chicken comparative proteomics human mammals mass spectrometry parrots

Does a Gravitational Aberration Contribute to the Accelerated Expansion of the Universe?

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Communications in Computational Physics 2009年第5期5卷 1030-1044页

作者： michal Krizek Institute of Mathematics Academy of SciencesZitna 25CZ-11567 Prague 1Czech Republic

An arbitrarily small positive value of the gravitational aberration slightly increases the angular momentum of a two-body and multiple body *** could potentially contribute to the accelerated expansion of the whole *** present some geometrical,physical,geophysical,heliophysical,climatological,cosmological,and astronomical observational arguments,and also numerical tests to support this *** found a remarkable coincidence between the Hubble constant and the increasing distance of the Moon from the Earth,that is not only due to tidal *** examples illustrating the expansion caused by the gravitational aberration are *** will be modeled by a nonautonomous system of ordinary differential equations with delay.

关键词： Hubble constant causality gravitation Earth Moon Mars Runge-Kutta method

On UMTS Capacity and Coverage Link-level Studies

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China Communications 2007年第2期4卷 16-25页

作者： michal Wagrowski Department of Telecommunications AGH University of Science and TechnologyAl.Mickiewicza 3030-059 KrakowPOLAND

There are a lot of performance studies concerning WCDMA radio interface in terms of its capacity and *** article gathers the most important issues related to this topic and indicates areas where the analytical as well as simulation-based(both static and dynamic) approach should be *** presented considerations address issues of the network environment modeling and parameters assumption with relevance to the network planning and optimization *** uplink and downlink are included in the analysis,taking introduced limitations into *** results of performance tests based on static simulations are presented.

关键词： UMTS WCDMA modeling planning optimization interference and performance analysis traffic distribution antenna tilt

Do historical maps show the maximal anthropopressure in the Carpathians?

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Journal of Mountain Science 2021年第8期18卷 2184-2200页

作者： michal Sobala University of Silesia Faculty of Natural Sciences60 Będzińska str.Sosnowiec41-200Poland

Many landscapes bear the marks of historical land *** marks can be the basis for a reconstruction of a historical land use structure as some of them are typical of different types of human *** aim of this paper is to determine whether Austrian cadastral maps from the 19th century present the image of the most transformed environment in the Western Carpathians as a result of agricultural *** use structure and terrain forms were detected based on Austrian cadastral maps from 1848,airborne laser scanning and field *** two of the test areas,the percentage of arable fields was higher among the plots with stone mounds than the percentage among the plots without *** the third test area,the relationship was ***,lynchets,terraces and stone walls sometimes occur in plots that were not arable fields in ***,the Austrian cadastral maps from 1848 could not reflect the maximal range of arable fields in the Carpathians in the 19th ***,it is impossible to determine the historical structure of land use ***,an inventory of terrain forms can be used to assess land use when historical maps have not preserved or when available maps do not present land use in detail.

关键词： Land abandonment Historical land use Airborne laser scanning Anthropogenic landforms Stone mounds Stone walls

Birds in rocky habitats of the Tatra Mountains (Carpathians)： species diversity and multiple ecological relationships

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Journal of Mountain Science 2016年第6期13卷 1078-1084页

作者： michal CIACH Filip KOWALSKI Department of Forest Biodiversity Institute of Forest Ecology and SilvicultureFaculty of ForestryUniversity of Agricultureal.29 Listopada 4531-425 KrakowPoland

Rocky habitats are regarded as biodiversity hot-spots. Along with high species diversity, diverse ecological relationships can be observed in these habitats. Large groups of bird species use rocks in various ways： as perching/roosting sites, breeding or foraging habitats, information exchange sites, display arenas or as sources of minerals and water. Because of the inaccessibility of these environments, their role and importance to animals has been underestimated. We evaluated the use of rocky habitats by birds in the Tatra Mountains （49°13′N; 19°57′E, Carpathians, central Europe）. Rocky habitats were used by 29 bird species, eight of which used cliffs directly （i.e. for nesting, foraging or resting）. The number of species recorded as using cliffs was correlated with the surface area of the cliff face. A total of 2o forms of rocky habitat use were recorded, in five behavioural categories： vocalization, foraging, perching, flight and nesting. Prevailing behaviours were flying by a rock face, circling above the face, and vocalization on a tree/shrub growing next to a rock. Rocks provide a nesting habitat for specialized petrophilic species and permit the existence of numerous ecological relations between species and habitats. The results of this study show that rocky habitats support the diversity of ecological relationships.

关键词： Bird community Rock Cliff Mountains Alpine species Ecological relationships