337 research outputs found

    Исследование влияния нитрата кальция на свойства тампонажного цемента

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    A new high repetitive, compact and low cost gas discharge based EUV "lamp" has been studied as an alternative to laser-produced plasmas as EUV sources. First results using oxygen in a fast discharge of electrically stored energy around 1 J lead to a conversion efficiency of about 0. 1 per cent for the emission at 13.0 nm which is suited for the use with Mo/Si-multilayer mirrors. Using Xenon a broadband emission in the investigated wavelength range from 10 nm to 18 nm is observed. With a first version a source with 40 W electrical input power could be demonstrated that emits about 50 mW/(4pisr) around 13 nm at a repetition rate of 150 Hz. No debris and no electrode erosion was observed after more than 10 (exp 7) pulses done up to now. Making use of the remaining optimisation potential this concept seems to be promising to fulfil the requirements of extreme-ultraviolet lithography

    Отказоустойчивый многофазный асинхронный электропривод с несинусоидальными токами

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    Рассмотрен принцип построения многофазного асинхронного электропривода, позволяющего при неоднократных отказах преобразователя частоты и двигателя обеспечить отказоустойчивое управление, на основе программируемых несинусоидальных токов с восстановлением работоспособности за счет активизации алгоритма восстановления в управляющем микроконтроллере. Приведены результаты моделирования для аварийной ситуации типа "обрыв фазы" для случая трехфазного двигателя с частичным восстановлением работоспособности асинхронного двигателя

    Oxygen hole formation controls stability in LiNiO2 cathodes

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    Ni-rich lithium-ion cathode materials achieve both high voltages and capacities but are prone to structural instabilities and oxygen loss. The origin of the instability lies in the pronounced oxidation of O during delithiation: for LiNiO2, NiO2, and the rock salt NiO, density functional theory and dynamical mean-field theory calculations based on maximally localized Wannier functions yield a Ni charge state of ca. +2, with O varying between −2 (NiO), −1.5 (LiNiO2), and −1 (NiO2). Calculated X-ray spectroscopy Ni K and O K-edge spectra agree well with experimental spectra. Using ab initio molecular dynamics simulations, we observe loss of oxygen from the (012) surface of delithiated LiNiO2, two surface O⋅− radicals combining to form a peroxide ion, and the peroxide ion being oxidized to form O2, leaving behind two O vacancies and two O2− ions. Preferential release of 1O2 is dictated via the singlet ground state of the peroxide ion and spin conservation

    Интеллектуальные энергосистемы. Т. 1

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    Настоящий сборник содержит материалы V Международного молодежного форума "Интеллектуальные энергосистемы", проведенного 9 - 13 октября 2017г. на базе Энергетического института Томского политехнического университета

    Numerical experiments on the atmospheric response to cold equatorial Pacific conditions ("La Nina") during northern summer

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    The effect of cold conditions in the central and eastern Equatorial Pacific during Northern Summer is examined in a series of numerical experiments with the low resolution (T21) atmospheric general circulation model ECHAM2. Anomalous sea surface temperatures (SST) as observed in June 1988 were prescribed and the effect on the global circulation is examined. In the model atmosphere, the anomalous cold water in the Equatorial Pacific excites a strong and stable response over the tropical Central and East Pacific. From here stationary Rossby waves radiate into both hemispheres. The Northern Hemisphere wave train is weak and affects only the Northeast Pacific area; the Southern Hemisphere wave train arches from the Central Pacific over the southern tip of South America to the South Atlantic. This response is not only present in the basic anomaly experiment with the T21 GCM but also in experiments with SST anomalies confined to the tropics and with an envelope- forrnulation of the SST anomalies, in experiments with a linear model, and in high resolution (T42) model experiments. The model output is also compared to the actually observed atmospheric state in June 1988. The model simulations do not reproduce the global circulation anomalies which were observed in June 1988. The model experiments are inconclusive with respect to the question of whether the North American drought observed in summer 1988 was related to the anomalous SST conditions in the Subtropical and Tropical Pacific. An explanatory analysis with a linear model reacting to prescribed heating anomalies as well as with the high-resolution GCM indicates that the model overreacted to the equatorial SST anomalies but almost ignored the contemporaneous subtropical SST anomalies on the Southern Hemisphere

    Can we quantify sediment recycling in Italy's post-collisional subduction system?

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    Recycling of Earth's crustal components through subduction contributes to the observed geochemical heterogeneity in worldwide lavas, yet quantifying the in- and output fluxes is difficult because of the unknown compositions of subducted components and sediment transfer processes in subduction zones. Italian post-collisional magmatism is often mafic but potassiumrich, suggesting a significant contribution of subducted sediments in this complex geodynamic setting. Isotopic and elemental variability in the volcanic products across Italy likely reflects sediment recycling with variable composition and quantity from north to south. Here we report the geochemical compositions of sediments that accreted to the Apennine accretionary prism whose lateral counterparts have potentially subducted and contributed to the Italian melt source. The aim is to use the major-, trace- and Sr- Nd-Pb isotope compositions of the sediments and Italy's volcanic products to quantify subduction recycling through melt modelling. Sediments were collected from the northern-, central- and southern Apennines (Liguria, Emilia-Romagna, Umbria and Calabria) with a focus on exhumed units from below the various decollement levels. These included Triassic to Jurassic deep sea sediments in ophiolitic sequences deposited in the Ligurian- Piemonte Oceanic Basin, and Triassic to Neogene distal units of the Adria continental margin. End-member compositions are defined by deep sea clays and metapelites rich in K2O, SiO2, LILE, HFSE, REE with high 87Sr/86Sr (0.7458) and 206Pb/204Pb (19.4), and marls poor in K2O, SiO2, LILE, HFSE, REE, but rich in CaO and Sr, with low 87Sr/86Sr (0.7083) and 206Pb/204Pb (18.7). The geochemical compositions of the most primitive volcanics and olivine-hosted melt inclusions will be used to reconstruct subduction recycling processes by melt modelling of a sediment metasomatized mantle wedge. Sediment transport mechanisms, sediment/vein mineralogy, melting behavior, and melt extraction processes will be evaluated

    Реинжиниринг процессов в отделе экономики и финансов Красноярского ЦФТО с использованием BestPractices

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    The development of new types of sophisticated soft x-ray sources requires the knowledge of their emission characteristics such as photon flux, spectral distribution, and size of the radiation source. Calibrated spectrographs for the soft x-ray region are needed to determine these properties. The components of a soft x-ray spectrograph consisting of a pinhole gold transmission grating and a charge coupled device (CCD) camera are calibrated at the radiometry laboratory of the Physikalisch-Technische Bundesanstalt using the synchrotron radiation facility BESSY. Two different kinds of CCD-based photon detectors (one thinned and back illuminated, one coated with a phosphorous layer) are compared with regard to their sensitivities in the spectral range between 50 eV and 1.7 keV. The results obtained for the thinned CCD are compared with theoretical calculations of the sensitivity

    Comparative chromosome painting discloses homologous Segments in distantly related mammals

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    Comparative chromosome painting, termed ZOO-FISH, using DNA libraries from flow sorted human chromosomes 1,16,17 and X, and mouse chromosome 11 discloses the presence of syntenic groups in distantly related mammalian Orders ranging from primates (Homo sapiens), rodents (Mus musculus), even-toed ungulates (Muntiacus muntjak vaginalis and Muntiacus reevesi) and whales (Balaenoptera physalus). These mammalian Orders have evolved separately for 55-80 million years (Myr). We conclude that ZOO-FISH can be used to generate comparative chromosome maps of a large number of mammalian species

    UV radiation enhanced oxygen vacancy formation caused by the PLD plasma plume

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    Pulsed Laser Deposition is a commonly used non-equilibrium physical deposition technique for the growth of complex oxide thin films. A wide range of parameters is known to influence the properties of the used samples and thin films, especially the oxygen-vacancy concentration. One parameter has up to this point been neglected due to the challenges of separating its influence from the influence of the impinging species during growth: the UV-radiation of the plasma plume. We here present experiments enabled by a specially designed holder to allow a separation of these two influences. The influence of the UV-irradiation during pulsed laser deposition on the formation of oxygen-vacancies is investigated for the perovskite model material SrTiO3. The carrier concentration of UV-irradiated samples is nearly constant with depth and time. By contrast samples not exposed to the radiation of the plume show a depth dependence and a decrease in concentration over time. We reveal an increase in Ti-vacancy–oxygen-vacancy-complexes for UV irradiated samples, consistent with the different carrier concentrations. We find a UV enhanced oxygen-vacancy incorporation rate as responsible mechanism. We provide a complete picture of another influence parameter to be considered during pulsed laser depositions and unravel the mechanism behind persistent-photo-conductivity in SrTiO3
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