المؤلفون: Cantinotti, M, Voges, I, Miller, O, Raimondi, F, Grotenhuis, H, Bharucha, T, Garrido, AO, Valsangiacomo, E, Roest, A, Sunnegardh, J, Salaets, T, Brun, H, Khraiche, D, Jossif, A, Schokking, M, Sabate-Rotes, A, Meyer-Szary, J, Deri, A, Koopman, L, Herberg, U, Sarvaas, GD, Leskinen, M, Tchana, B, Ten Harkel, ADJ, Odemis, E, Morrison, L, Steimetz, M, Laser, KT, Doros, G, Bellshan-Revell, H, Muntean, I, Anagostopoulou, A, Alpman, MS, Hunter, L, Ojala, T, Bhat, M, Olejnik, P, Wacker, J, Bonello, B, Ramcharan, T, Greil, G, Marek, J, DiSalvo, G, McMahon, CJ

المصدر: Cardiology in the young. :1-9

مصطلحات موضوعية: Medicin och hälsovetenskap

الوصول الحر: http://kipublications.ki.se/Default.aspx?queryparsed=id:155365666Test

المؤلفون: Deiev, I. S. Timchenko O. S., Olejnik, S. M., Potin, S. M., Kushnir, V. A., Mytrochenko, V. V., Perezhogin, S. A., Herzáň, A.

مصطلحات موضوعية: Nuclear Experiment

الوصف: Production of the ${^{55-57}}$Co nuclei on ${^{\rm nat}}$Ni in photonuclear reactions using bremsstrahlung gamma photon irradiation with end-point energy $E_{\rm{\gamma max}}$ between 35 and 94~MeV has been studied. The experiment was performed at the electron linear accelerator LUE-40 NSC KIPT using the methods of $\gamma$ activation and off-line $\gamma$-ray spectroscopy. The obtained experimental flux-averaged cross-sections $\langle{\sigma(E_{\rm{\gamma max}})}\rangle$ agree with the data found in literature. The theoretical flux-averaged cross-sections $\langle{\sigma(E_{\rm{\gamma max}})}\rangle_{\rm{th}}$ for the production of ${^{55-57}}$Co and ${^{55-57}}$Ni were estimated using the cross-section values $\sigma(E)$ from the TALYS1.95 code and bremsstrahlung spectra of gamma photons calculated by GEANT4.9.2. The experimental results for ${^{56,57}}$Co agree with the cumulative $\langle{\sigma(E_{\rm{\gamma max}})}\rangle_{\rm{th}}$. However theoretical prediction fails to reproduce the measured cross-sections for the production of ${^{55}}$Co.
Comment: 11 pages, 6 figures, 4 Tables

الوصول الحر: http://arxiv.org/abs/2407.09245Test

المؤلفون: Timchenko, I. S., Deiev, O. S., Olejnik, S. M., Potin, S. M., Kushnir, V. A., Mytrochenko, V. V., Perezhogin, S. A.

المصدر: Problems of Atomic Science and Technology 3 (2024) 15

مصطلحات موضوعية: Nuclear Experiment

الوصف: The photoproduction of the $^{\rm 93m}$Mo nucleus on natural molybdenum was studied using the electron beam of the LUE-40 linac RDC "Accelerator" NSC KIPT. Measurements were performed using the activation method and off-line $\gamma$-ray spectrometric technique. For the $^{\rm nat}$Mo($\gamma,x$n)$^{\rm 93m}$Mo reaction the experimental flux-averaged cross-section <$\sigma(E_{\rm \gamma max})$>$_\rm m$ at the bremsstrahlung end-point energy range of 38--93 MeV was first time determined. The theoretical values of the yields $Y_{\rm m,g}(E_{\rm \gamma max})$ and flux-averaged cross-sections <$\sigma(E_{\rm \gamma max})$>$_{\rm m,g}$ for the $^{\rm nat}$Mo($\gamma,x$n)$^{\rm 93m,g}$Mo reactions were calculated using the cross-sections $\sigma(E_{\rm \gamma})$ from the TALYS1.96 code for different gamma strength functions and level density models. The comparison showed strong discrepancies between the experimental values and the theoretical results of <$\sigma(E_{\rm \gamma max})$>$_m$.
Comment: 8 pages, 9 figures, 2 tables. arXiv admin note: text overlap with arXiv:2308.02243, arXiv:2311.03038

الوصول الحر: http://arxiv.org/abs/2407.09085Test

المؤلفون: Beckert, Sebastian, Schlitz, Richard, Skobjin, Gregor, Badura, Antonin, Leiviskä, Miina, Kriegner, Dominik, Scheffler, Daniel, Sala, Giacomo, Olejník, Kamil, Michez, Lisa, Baltz, Vincent, Thomas, Andy, Reichlová, Helena, Goennenwein, Sebastian T. B.

مصطلحات موضوعية: Condensed Matter - Materials Science, Condensed Matter - Mesoscale and Nanoscale Physics

الوصف: Slow magnetization relaxation processes are an important time-dependent property of many magnetic materials. We show that magnetotransport measurements based on a well-established current-reversal method can be utilized to implement a simple and robust screening scheme for such relaxation processes. We demonstrate our approach considering the anomalous Hall effect in a Pt/Co/AlOx trilayer model system, and then explore relaxation in {\tau} -MnAl films. Compared to magnetotransport experiments based on ac lock-in techniques, we find that the dc current-reversal method is particulary sensitive to relaxation processes with relaxation time scales on the order of seconds, comparable to the current-reversal measurement time scales.

الوصول الحر: http://arxiv.org/abs/2405.14460Test

المؤلفون: Betancourt, Ruben Dario Gonzalez, Zubáč, Jan, Geishendorf, Kevin, Ritzinger, Philipp, Růžičková, Barbora, Kotte, Tommy, Železný, Jakub, Olejník, Kamil, Springholz, Gunther, Büchner, Bernd, Thomas, Andy, Výborný, Karel, Jungwirth, Tomas, Reichlová, Helena, Kriegner, Dominik

مصطلحات موضوعية: Condensed Matter - Materials Science

الوصف: Recently, MnTe was established as an altermagnetic material that hosts spin-polarized electronic bands as well as anomalous transport effects like the anomalous Hall effect. In addition to these effects arising from altermagnetism, MnTe also hosts other magnetoresistance effects. Here, we study the manipulation of the magnetic order by an applied magnetic field and its impact on the electrical resistivity. In particular, we establish which components of anisotropic magnetoresistance are present when the magnetic order is rotated within the hexagonal basal plane. Our experimental results, which are in agreement with our symmetry analysis of the magnetotransport components, showcase the existence of an anisotropic magnetoresistance linked to both the relative orientation of current and magnetic order, as well as crystal and magnetic order.

الوصول الحر: http://arxiv.org/abs/2404.16516Test

المؤلفون: Surynek, M., Zubac, J., Olejnik, K., Farkas, A., Krizek, F., Nadvornik, L., Kubascik, P., Trojanek, F., Campion, R. P., Novak, V., Jungwirth, T., Nemec, P.

مصطلحات موضوعية: Condensed Matter - Materials Science, Condensed Matter - Disordered Systems and Neural Networks

الوصف: Experiments in materials with a compensated ordering of magnetic moments have demonstrated a potential for approaching the thermodynamic limit of the fastest and least-dissipative operation of a digital memory bit. In addition, these materials are very promising for a construction of energy-efficient analog devices with neuromorphic functionalities, which are inspired by computing-in-memory capabilities of the human brain. In this paper, we report on experimental separation of switching-related and heat-related resistance signal dynamics in memory devices microfabricated from CuMnAs antiferromagnetic metal. We show that the memory variable multilevel resistance can be used as a long-term memory (LTM), lasting up to minutes at room temperature. In addition, ultrafast reflectivity change and heat dissipation from nanoscale-thickness CuMnAs films, taking place on picosecond to hundreds of nanoseconds time scales, can be used as a short-term memory (STM). Information about input stimuli, represented by femtosecond laser pulses, can be transferred from STM to LTM after rehearsals at picosecond to nanosecond times in these memory devices, where information can be retrieved at times up to 10^15 longer than the input pulse duration. Our results open a route towards ultra-fast low-power implementations of spiking neuron and synapse functionalities using a resistive analog antiferromagnetic memory.
Comment: 21 pages, 4 figures

الوصول الحر: http://arxiv.org/abs/2401.17370Test

المؤلفون: Piotrowski, Jan, Wachnicki, Marek, Perlik, Mateusz, Podolak, Jakub, Rucki, Grzegorz, Brzozowski, Michał, Olejnik, Paweł, Kozłowski, Julian, Nocoń, Tomasz, Kozieł, Jakub, Giziński, Stanisław, Sankowski, Piotr

مصطلحات موضوعية: Computer Science - Computation and Language, Computer Science - Machine Learning, I.2.7

الوصف: X (formerly Twitter) has evolved into a contemporary agora, offering a platform for individuals to express opinions and viewpoints on current events. The majority of the topics discussed on Twitter are directly related to ongoing events, making it an important source for monitoring public discourse. However, linking tweets to specific news presents a significant challenge due to their concise and informal nature. Previous approaches, including topic models, graph-based models, and supervised classifiers, have fallen short in effectively capturing the unique characteristics of tweets and articles. Inspired by the success of the CLIP model in computer vision, which employs contrastive learning to model similarities between images and captions, this paper introduces a contrastive learning approach for training a representation space where linked articles and tweets exhibit proximity. We present our contrastive learning approach, CATBERT (Contrastive Articles Tweets BERT), leveraging pre-trained BERT models. The model is trained and tested on a dataset containing manually labeled English and Polish tweets and articles related to the Russian-Ukrainian war. We evaluate CATBERT's performance against traditional approaches like LDA, and the novel method based on OpenAI embeddings, which has not been previously applied to this task. Our findings indicate that CATBERT demonstrates superior performance in associating tweets with relevant news articles. Furthermore, we demonstrate the performance of the models when applied to finding the main topic -- represented by an article -- of the whole cascade of tweets. In this new task, we report the performance of the different models in dependence on the cascade size.

الوصول الحر: http://arxiv.org/abs/2312.07599Test

المؤلفون: Timchenko, I. S., Deiev, O. S., Olejnik, S. M., Potin, S. M., Kushnir, V. A., Mytrochenko, V. V., Perezhogin, S. A.

مصطلحات موضوعية: Nuclear Experiment

الوصف: The photoproduction of $^{95\rm m}$Nb on ${^{\rm nat}\rm{Mo}}$ was studied using the electron beam of the LUE-40 linac RDC "Accelerator" NSC KIPT. Measurements were performed using activation and off-line $\gamma$-ray spectrometric techniques. The experimental flux-averaged cross-section $\langle{\sigma(E_{\rm{\gamma max}})}\rangle_{\rm{m}}$ for the ${^{\rm nat}\rm{Mo}}(\gamma,x\rm np)^{95\rm m}$Nb reaction at the bremsstrahlung end-point energy range of 38--93 MeV has been first time obtained. The estimated values $\langle{\sigma(E_{\rm{\gamma max}})}\rangle_{\rm{g}}$ for the formation of $^{95}$Nb in the ground state and total cross-sections $\langle{\sigma(E_{\rm{\gamma max}})}\rangle_{\rm{tot}}$ for the studied reaction were determined. The theoretical values of the yields $Y_{\rm m,g,tot}(E_{\rm{\gamma max}})$ and flux-averaged cross-sections $\langle{\sigma(E_{\rm{\gamma max}})}\rangle_{\rm{m,g,tot}}$ for the ${^{\rm nat}\rm{Mo}}(\gamma,x\rm np)^{95\rm m,g,tot}$Nb reactions were calculated using the cross-sections $\sigma(E)$ from the TALYS1.95 code for six different level density models. The comparison showed a significant excess of the experimental results over the theoretical $\langle{\sigma(E_{\rm{\gamma max}})}\rangle_{\rm{m,g,tot}}$ values.
Comment: arXiv admin note: substantial text overlap with arXiv:2308.02243

الوصول الحر: http://arxiv.org/abs/2311.03038Test

المؤلفون: Timchenko, I. S., Deiev, O. S., Olejnik, S. M., Potin, S. M., Kushnir, V. A., Mytrochenko, V. V., Perezhogin, S. A.

مصطلحات موضوعية: Nuclear Experiment

الوصف: The results of the photoproduction of isomeric pairs from the ({\gamma},xn) and ({\gamma},pxn) reactions on nuclei from Zr up to Ta at the bremsstrahlung end-point energy range 30-100 MeV are systematized. Measurements were performed at the electron beam of the LUE-40 linac RDC "Accelerator" NSC KIPT using the activation method and off-line {\gamma}-ray spectrometric technique. The theoretical isomeric ratios IR for the nuclei-products of studied reactions were calculated using the cross-sections {\sigma}(E) from the TALYS1.95 code for six different level density models. The data from the international databases were additionally used to compare experimental results and theoretical predictions. The obtained results let us make conclusions about trends of values and energy dependence of IR in studied photonuclear reactions. Further directions of experimental research in the RDC "Accelerator" NSC KIPT are discussed.
Comment: 10 pages, 13 figures, 1 table

الوصول الحر: http://arxiv.org/abs/2311.03020Test

المؤلفون: Olejnik, Artur, Jóźwiak, Hubert, Gancewski, Maciej, Quintas-Sánchez, Ernesto, Dawes, Richard, Wcisło, Piotr

مصطلحات موضوعية: Physics - Chemical Physics, Physics - Atmospheric and Oceanic Physics, Quantum Physics

الوصف: The remote sensing of abundance and properties of HCl -- the main atmospheric reservoir of Cl atoms which directly participate in ozone depletion -- are important for monitoring the partitioning of chlorine between "ozone-depleting" and "reservoir" species. Such remote studies require knowledge of the shapes of molecular resonances of HCl, which are perturbed by collisions with the molecules of the surrounding air. In this work, we report the first fully quantum calculations of collisional perturbations of the shape of a pure rotational line in H$^{35}$Cl perturbed by an air-relevant molecule (as the first model system we choose the R(0) line in HCl perturbed by O$_2$). The calculations are performed on our new highly-accurate HCl($X^1\Sigma^+$)-O$_2$($X^3\Sigma^-_g$) potential energy surface. In addition to pressure broadening and shift, we determine also their speed dependencies and the complex Dicke parameter. This gives important input to the community discussion on the physical meaning of the complex Dicke parameter and its relevance for atmospheric spectra (previously, the complex Dicke parameter for such systems was mainly determined from phenomenological fits to experimental spectra and the physical meaning of its value in that context is questionable). We also calculate the temperature dependence of the line-shape parameters and obtain agreement with the available experimental data. We estimate the total combined uncertainties of our calculations at 2% relative RMSE residuals in the simulated line shape at 296~K. This result constitutes an important step towards computational population of spectroscopic databases with accurate ab initio line-shape parameters for molecular systems of terrestrial atmospheric importance.
Comment: 15 pages, 7 figures, The following article has been accepted by The Journal of Chemical Physics. After it is published, it will be found at https://pubs.aip.org/aip/jcpTest

الوصول الحر: http://arxiv.org/abs/2309.08413Test