1,518 research outputs found
Uakitite, VN, a new mononitride mineral from uakit iron meteorite (IIAB)
Uakitite was observed in small troilite–daubréelite (±schreibersite) inclusions (up to 100 µm) and in large troilite–daubréelite nodules (up to 1 cm) in Fe-Ni-metal (kamacite) of the Uakit iron meteorite (IIAB), Republic of Buryatia, Russia. Such associations in the Uakit meteorite seemed to form due to high-temperature (>1000 °C) separation of Fe-Cr-rich sulfide liquid from Fe-metal melt. Most inclusions represent alternation of layers of troilite and daubréelite, which may be a result of solid decay of an initial Fe-Cr-sulfide. These inclusions are partially resorbed and mainly located in fissures of the meteorite, which is now filled with magnetite, and rarely other secondary minerals. Phase relations indicate that uakitite is one of the early minerals in these associations. It forms isometric (cubic) crystals (in daubréelite) or rounded grains (in schreibersite). The size of uakitite grains is usually less than 5 µm. It is associated with sulfides (daubréelite, troilite, grokhovskyite), schreibersite and magnetite. Carlsbergite CrN, a more abundant nitride in the Uakit meteorite, was not found in any assemblages with uakitite. Physical and optical properties of uakitite are quite similar to synthetic VN: yellow and transparent phase with metallic luster; Mohs hardness: 9–10; light gray color with a pinky tint in reflected light; density (calc.) = 6.128 g/cm3. Uakitite is structurally related to the osbornite group minerals: carlsbergite CrN and osbornite TiN. Structural data were obtained for three uakitite crystals using the electron backscatter diffraction (EBSD) technique. Fitting of the EBSD patterns for a synthetic VN model (cubic, Fm-3m, a = 4.1328(3) Å; V = 70.588(9) Å3; Z = 4) resulted in the parameter MAD = 0.14–0.37° (best-good fit). Analytical data for uakitite (n = 54, in wt. %) are: V, 71.33; Cr, 5.58; Fe, 1.56; N, 21.41; Ti, below detection limit (<0.005). The empirical formula (V0.91Cr0.07Fe0.02)1.00N1.00 indicates that chromium incorporates in the structure according to the scheme V3+ → Cr3+ (up to 7 mol. % of the carlsbergite end-member). © 2020 by the authors. Licensee MDPI, Basel, Switzerland.Russian Foundation for Basic Research, RFBR: 17-05-00129, IGM SD 0330-2016-0005Government Council on Grants, Russian FederationMinistry of Science and Higher Education of the Russian FederationFunding: The investigations were partly supported by RFBR (grant 17-05-00129) and the State assignment project (IGM SD 0330-2016-0005). This work was also supported by the Initiative Project of Ministry of Science and Higher Education of the Russian Federation and by Act 211 of the Government of the Russian Federation, agreement no. 02.A03.21.0006
Adaptive working memory training does not produce transfer effects in cognition and neuroimaging
Despite growing interest in cognitive interventions from academia and industry, it remains unclear if working memory (WM) training, one of the most popular cognitive interventions, produces transfer effects. Transfer effects are training-induced gains in performance in untrained cognitive tasks, while practice effects are improvements in trained task. The goal of this study was to evaluate potential transfer effects by comprehensive cognitive testing and neuroimaging. In this prospective, randomized-controlled, and single-blind study, we administered an 8-week n-back training to 55 healthy middle-aged (50–64 years) participants. State-of-the-art multimodal neuroimaging was used to examine potential anatomic and functional changes. Relative to control subjects, who performed non-adaptive WM training, no near or far transfer effects were detected in experimental subjects, who performed adaptive WM training. Equivalently, no training-related changes were observed in white matter integrity, amplitude of low frequency fluctuations, glucose metabolism, functional and metabolic connectivity. Exploratory within-group comparisons revealed some gains in transfer tasks, which, however, cannot be attributed to an increased WM capacity. In conclusion, WM training produces transfer effects neither at the cognitive level nor in terms of neural structure or function. These results speak against a common view that training-related gains reflect an increase in underlying WM capacity. Instead, the presently observed practice effects may be a result of optimized task processing strategies, which do not necessarily engage neural plasticity
Assessment of the comagmaticity of gabbroids and syenites of the Arsentyevsky massif (Western Transbaikalia)
Object . The results of geochronological and isotope-geochemical studies of the Arsentyevsky titaniferous gabbro-syenite massif of the Western Transbaikalia, which previously referred to the gabbro-syenite series of a two-phase structure are presented. The rocks of the massif contain an increased concentration of titanomagnetite, ilmenite, magnetite and in some cases apatite and are considered as complex iron-titanium ores. Methods. The studies were performed by silicate analysis methods, XRF and ICP-MS; age determination for zircons was carried out by LA-ICP-MS and SHRIMP-II methods. The composition of minerals on the X-ray microarray analyzer MAP-3 and electron microscope LEO-1430 was studied. Results. In the basites, a standard trend is observed for the evolution of compositions from melanocratic to terminal leucocratic differences with an increase in the content of silica, alumina, and sodium, and a decrease in magnesium and calcium. Syenites differ from anorthosites in the content of impurity elements including rubidium, niobium, strontium and REE The geochronological studies of rocks of Arsent’evsky gabbro-syenite massif, showed a significant time gap in the formation of gabbroids relative to syenites. The U-Pb age of the gabbroids was 279.5 ± 2.0 Ma, alkali feldspar syenites have age 229.4 ± 2.8 Ma, and biotite syenites - 226 ± 2.4 Ma. Conclusion. The obtained results by age and data on the geochemical features of the rocks made it possible to conclude that there was no genetic relationship between basites and syenites. Petrochemical and geochemical features of biotite and alkali-feldspar syenites proved to be close to the rocks of the Mesozoic Kunaleisky complex
Using fractional exhaled nitric oxide (FeNO) to diagnose steroid-responsive disease and guide asthma management in routine care
Acknowledgements We thank Robin Taylor for his informative thinking and publications on FeNO, which have helped to influence and direct the thinking of the authors. Funding Extraction of the real-life dataset was funded by Research in Real Life Limited, the analysis of the dataset and the writing of this manuscript were co-funded (50:50) by Research in Real Life Limited and Aerocrine.Peer reviewedPublisher PD
МАФИЧЕСКИЕ ВКЛЮЧЕНИЯ И МИНГЛИНГ‐СТРУКТУРЫ В АПЛИТАХ ОШУРКОВСКОГО МАССИВА (ЗАПАДНОЕ ЗАБАЙКАЛЬЕ)
Our study of aplite dykes cross‐cutting the Oshurkov basite massif revealed drop‐shaped inclusions of the monzonite composition. These are crystallized drops of basite melts, which show traces of the interaction with the host acidic melt. The Ar‐Ar method was applied to determine the age of the aplites (114.9 Ma for biotite) and the monzonite inclusions (123.3 Ma for amphibole).Статья посвящена вещественному исследованию даек аплитов, секущих Ошурковский базитовый массив. В нескольких телах аплитов обнаружены каплевидные включения монцонитового состава. Установлено, что они являются закристаллизованными каплями базитового расплава и имеют следы взаимодействия с вмещающим кислым расплавом. Ar‐Ar методом определен возраст аплитов (по биотиту – 114.9 млн лет) и монцонитовых включений (по амфиболу – 123.3 млн лет)
Antifascism, the 1956 Revolution and the politics of communist autobiographies in Hungary 1944-2000
This is a postprint of an article whose final and definitive form has been published in Europe-Asia Studies © 2006 University of Glasgow; Europe-Asia Studies is available online at http://www.informaworld.com.Using oral history, this contribution explores the reshaping of individuals' public and private autobiographies in response to different political environments. In particular, it analyses the testimony of those who were communists in Hungary between 1945 and 1956, examining how their experiences of fascism, party membership, the 1956 Revolution and the collapse of communism led them in each case to refashion their life stories. Moreover, it considers how their biographies played varying functions at different points in their lives: to express identification with communism, to articulate resistance and to communicate ambition before 1956; to protect themselves from the state after 1956; and to rehabilitate themselves morally in a society which stigmatised them after 1989.I didn't use this word 'liberation' (felszabadulás), because in 1956 my life really changed. Everybody's lives went through a great change, but mine especially. … I wasn't disgusted with myself that I had called the arrival of the Red Army in 1945 a liberation, but [after 1956] I didn't use it anymore
Journal Staff
We present the first measurements of the differential cross section d sigma/dp(T)(gamma) for the production of an isolated photon in association with at least two b-quark jets. The measurements consider photons with rapidities vertical bar y(gamma)vertical bar < 1.0 and transverse momenta 30 < p(T)(gamma) < 200 GeV. The b-quark jets are required to have p(T)(jet) > 15 GeVand vertical bar y(jet)vertical bar < 1.5. The ratio of differential production cross sections for gamma + 2 b-jets to gamma + b-jet as a function of p(T)(gamma) is also presented. The results are based on the proton-antiproton collision data at root s = 1.96 TeV collected with the D0 detector at the Fermilab Tevatron Collider. The measured cross sections and their ratios are compared to the next- to- leading order perturbative QCD calculations as well as predictions based on the k(T)- factorization approach and those from the sherpa and pythia Monte Carlo event generators
Measurement of the top quark mass using the matrix element technique in dilepton final states
We present a measurement of the top quark mass in pp¯ collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron collider. The data were collected by the D0 experiment corresponding to an integrated luminosity of 9.7 fb−1. The matrix element technique is applied to tt¯ events in the final state containing leptons (electrons or muons) with high transverse momenta and at least two jets. The calibration of the jet energy scale determined in the lepton+jets final state of tt¯ decays is applied to jet energies. This correction provides a substantial reduction in systematic uncertainties. We obtain a top quark mass of mt=173.93±1.84 GeV
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