Topology of event distribution as a generalized definition of phase transitions in finite systems

We propose a definition of phase transitions in finite systems based on topology anomalies of the event distribution in the space of observations. This generalizes all the definitions based on the curvature anomalies of thermodynamical potentials and provides a natural definition of order parameters. The proposed definition is directly operational from the experimental point of view. It allows to study phase transitions in Gibbs equilibria as well as in other ensembles such as the Tsallis ensemble.Comment: 4 pages, 3 figure

Exploring the low-lying electronic states of C4H6OS isomers, dihydro-2(3H)-thiophenone and dihydro-3(2H)-thiophenone

PLV also acknowledges his visiting professor position at Federal University of Paraná, Curitiba, Brazil. The authors wish to acknowledge the beam time at the ISA synchrotron, Aarhus University, Denmark. This contribution is also based upon work from the COST Action CA18212-Molecular Dynamics in the GAS phase (MD-GAS), supported by COST (European Cooperation in Science and Technology). DD acknowledges support from the CaPPA project (Chemical and Physical Properties of the Atmosphere) funded by the French National Research Agency (ANR) through the PIA (Programme d'Investissement d'Avenir) under contract no. ANR-10-LABX-005 ; the Région Hauts de France and the Ministère de l'Enseignement Supérieur et de la Recherche (CPER ECRIN) and the European Fund for Regional Economic Development for their financial support. This work was performed using HPC resources from GENCI-TGCC (Grant No. 2023–A0130801859 ) and the Centre de Ressources Informatiques (CRI) of the Université de Lille. Publisher Copyright: © 2024 The Author(s)Results of a detailed study on the electronic state spectroscopy of C4H6OS isomers, dihydro-2(3H)-thiophenone and dihydro-3(2H)-thiophenone, have been obtained from high-resolution vacuum ultraviolet photoabsorption experiments together with quantum chemical calculations. The absolute photoabsorption cross-sections in the 3.7–10.7 eV energy range were obtained at the AU-UV beam line, ASTRID2 synchrotron radiation facility. The absorption spectra exhibit features due to transitions into valence and Rydberg states, superimposed on vibrational fine structure which appear much weaker in the photoabsorption spectrum of dihydro-3(2H)-thiophenone. Assignments have been proposed for some of the absorption bands with the aid of ab initio calculations at the equation-of-motion coupled-cluster singles and doubles level (EOM-CCSD) providing vertical excitation energies and oscillator strengths. The nature of the transitions was assessed by visual inspection of the natural orbitals for each transition and the average values from the electronic radial spatial extents of the electronic cloud. A comparison between the vibrational structure observed in the experimental spectra suggests relevant C[dbnd]O stretching excitations for both molecules, with important CH2 twisting and rocking modes for dihydro-2(3H)-thiophenone and ring stretching modes for dihydro-3(2H)-thiophenone. Photolysis lifetimes from 0 up to 50 km altitude in the Earth's atmosphere for both chemical compounds have been estimated from the absolute photoabsorption cross-sections.publishersversionpublishe

Nuclear break-up of 11Be

The break-up of 11Be was studied at 41AMeV using a secondary beam of 11Be from the GANIL facility on a 48Ti target by measuring correlations between the 10Be core, the emitted neutrons and gamma rays. The nuclear break-up leading to the emission of a neutron at large angle in the laboratory frame is identified with the towing mode through its characteristic n-fragment correlation. The experimental spectra are compared with a model where the time dependent Schrodinger equation (TDSE) is solved for the neutron initially in the 11 Be. A good agreement is found between experiment and theory for the shapes of neutron experimental energies and angular distributions. The spectroscopic factor of the 2s orbital is tentatively extracted to be 0.46+-0.15. The neutron emission from the 1p and 1d orbitals is also studied

Preclinical Evaluation of Antitumor Efficacy of a New Radiopharmaceutical Based on Thermoresponsive Carrier and Samarium-153

This work is devoted to studying the in vivo antitumor efficacy of the new injection radiopharmaceutical based on thermoresponsive polymer and β−-emitting radionuclide samarium-153 (153Sm-KARP-CheM). The study of in vivo antitumor efficacy was performed using mice F1 and C57Bl/6 with transplanted subcutaneously sarcoma S37 and melanoma B16, respectively. The animals received single intratumoral bolus injections of 37 MBq (1 mCi), or 18.5 MBq (0.5 mCi) of 153Sm-KARP-CheM, or saline in a volume 0.1 ml. The efficacy of antitumortreatment was evaluated using tumor growth inhibition index (TGI, %) and increase of average life span (ILS, %). The most meaningful therapeutic efficacy after intratumoral injection of 153Sm-KARPCheM was observed in melanoma-bearing mice C57Bl/6. The highest values of TGI for melanoma B16 were 79.5% and 79.6% after treatment with 18.5 MBq or 37 MBq, respectively. An increase of average life span by 17.1% was found in group of melanoma-bearing mice treated with 37 MBq of 153Sm-KARP-CheM only. Tumor growth inhibition of sarcoma S37 was slightly lower as compared with melanoma B16: 62.5% and 59.0% in 37 MBq and 18.5 MBq groups, respectively. 153Sm-KARP-CheM didn’t increase average life span of treated animals. In conclusion, 153Sm-KARP-CheM seems to be effective radiopharmaceutical for local tumor radiotherapy. Keywords: thermoresponsive polymer, samarium-153, radionuclide therapy of cancer, sarcoma S37, melanoma B16, antitumor efficacy

Topology of event distribution as a generalized definition of phase transitions in finite systems

We propose a definition of phase transitions in finite systems based on topology anomalies of the event distribution in the space of observations. This generalizes all the definitions based on the curvature anomalies of thermodynamical potentials and provides a natural definition of order parameters. The proposed definition is directly operational from the experimental point of view. It allows to study phase transitions in Gibbs equilibria as well as in other ensembles such as the Tsallis ensemble.Comment: 4 pages, 3 figure

Syzygies in equivariant cohomology for non-abelian Lie groups

We extend the work of Allday-Franz-Puppe on syzygies in equivariant cohomology from tori to arbitrary compact connected Lie groups G. In particular, we show that for a compact orientable G-manifold X the analogue of the Chang-Skjelbred sequence is exact if and only if the equivariant cohomology of X is reflexive, if and only if the equivariant Poincare pairing for X is perfect. Along the way we establish that the equivariant cohomology modules arising from the orbit filtration of X are Cohen-Macaulay. We allow singular spaces and introduce a Cartan model for their equivariant cohomology. We also develop a criterion for the finiteness of the number of infinitesimal orbit types of a G-manifold.Comment: 28 pages; minor change

The OSACA Database and a Kinematic Analysis of Stars in the Solar Neighborhood

We transformed radial velocities compiled from more than 1400 published sources, including the Geneva--Copenhagen survey of the solar neighborhood (CORAVEL-CfA), into a uniform system based on the radial velocities of 854 standard stars in our list. This enabled us to calculate the average weighted radial velocities for more than 25~000 HIPPARCOS stars located in the local Galactic spiral arm (Orion arm) with a median error of +-1 km/s. We use these radial velocities together with the stars' coordinates, parallaxes, and proper motions to determine their Galactic coordinates and space velocities. These quantities, along with other parameters of the stars, are available from the continuously updated Orion Spiral Arm CAtalogue (OSACA) and the associated database. We perform a kinematic analysis of the stars by applying an Ogorodnikov-Milne model to the OSACA data. The kinematics of the nearest single and multiple main-sequence stars differ substantially. We used distant (r\approx 0.2 kpc) stars of mixed spectral composition to estimate the angular velocity of the Galactic rotation -25.7+-1.2 km/s/kpc, and the vertex deviation,l=13+-2 degrees, and detect a negative K effect. This negative K effect is most conspicuous in the motion of A0-A5 giants, and is equal to K=-13.1+-2.0 km/s/kpc.Comment: 16 pages, 8 figure

Measurements of hydrogen cyanide (HCN) and acetylene (C2H2) from the Infrared Atmospheric Sounding Interferometer (IASI)

Hydrogen cyanide (HCN) and acetylene (C2H2) are ubiquitous atmospheric trace gases with medium lifetime, which are frequently used as indicators of combustion sources and as tracers for atmospheric transport and chemistry. Because of their weak infrared absorption, overlapped by the CO2 Q branch near 720 cm−1, nadir sounders have up to now failed to measure these gases routinely. Taking into account CO2 line mixing, we provide for the first time extensive measurements of HCN and C2H2 total columns at Reunion Island (21° S, 55° E) and Jungfraujoch (46° N, 8° E) in 2009–2010 using observations from the Infrared Atmospheric Sounding Interferometer (IASI). A first order comparison with local ground-based Fourier transform InfraRed (FTIR) measurements has been carried out allowing tests of seasonal consistency which is reasonably captured, except for HCN at Jungfraujoch. The IASI data shows a greater tendency to high C2H2 values. We also examine a nonspecific biomass burning plume over austral Africa and show that the emission ratios with respect to CO agree with previously reported values

Lyman-alpha Absorption from Heliosheath Neutrals

We assess what information HST observations of stellar Ly-alpha lines can provide on the heliosheath, the region of the heliosphere between the termination shock and heliopause. To search for evidence of heliosheath absorption, we conduct a systematic inspection of stellar Ly-alpha lines reconstructed after correcting for ISM absorption (and heliospheric/astrospheric absorption, if present). Most of the stellar lines are well centered on the stellar radial velocity, as expected, but the three lines of sight with the most downwind orientations relative to the ISM flow (Chi1 Ori, HD 28205, and HD 28568) have significantly blueshifted Ly-alpha lines. Since it is in downwind directions where heliosheath absorption should be strongest, the blueshifts are almost certainly caused by previously undetected heliosheath absorption. We make an initial comparison between the heliosheath absorption and the predictions of a pair of heliospheric models. A model with a complex multi-component treatment of plasma within the heliosphere predicts less absorption than a model with a simple single-fluid treatment, which leads to better agreement with the data. Finally, we find that nonplanetary energetic neutral atom (ENA) fluxes measured by the ASPERA-3 instrument on board Mars Express, which have been interpreted as being from the heliosheath, are probably too high to be consistent with the relative lack of heliosheath absorption seen by HST. This would argue for a local interplanetary source for these ENAs instead of a heliosheath source.Comment: 27 pages, 7 figures, AASTEX v5.0, accepted by Ap

Spectroscopic analysis of the B/Be visual binary HR 1847

We studied both components of a slightly overlooked visual binary HR 1847 spectroscopically to determine its basic physical and orbital parameters. Basic stellar parameters were determined by comparing synthetic spectra to the observed echelle spectra, which cover both the optical and near-IR regions. New observations of this system used the Ond\v{r}ejov and Rozhen 2-m telescopes and their coud\'e spectrographs. Radial velocities from individual spectra were measured and then analysed with the code {\FOTEL} to determine orbital parameters. The spectroscopic orbit of HR 1847A is presented for the first time. It is a single-lined spectroscopic binary with a B-type primary, a period of 719.79 days, and a highly eccentric orbit with e=0.7. We confirmed that HR 1847B is a Be star. Its H\alpha emission significantly decreased from 2003 to 2008. Both components have a spectral type B7-8 and luminosity class IV-V.Comment: Astronomy and Astrophysics, accepte