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Social learning in cluster initiatives
PublikacjaPurpose – The purpose of the paper is to portray social learning in cluster initiatives (CIs), namely: 1) to explore, with the lens of the communities of practice (CoPs) theory, in what ways social learning occurs in CIs; 2) to discover how various CoPs emerge and evolve in CIs to facilitate a collective journey in their learning process. Subsequently, the authors address the research questions: In what ways does social learning...
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Blurred quantum Darwinism across quantum reference frames
PublikacjaQuantum Darwinism describes objectivity of quantum systems via their correlations with their environment--information that hypothetical observers can recover by measuring the environments. However, observations are done with respect to a frame of reference. Here, we take the formalism of [Giacomini, Castro-Ruiz, & Brukner. Nat Commun 10, 494 (2019)], and consider the repercussions on objectivity when changing quantum reference...
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Experimental test of nonclassicality with arbitrarily low detection efficiency
PublikacjaWe theoretically introduce and experimentally demonstrate the realization of a nonclassicality test that allows for arbitrarily low detection efficiency without invoking an extra assumption of independence of the devices. Our test and its implementation is set in a prepare-and-measure scenario with an upper limit on the classical communication capacity of the channel through which the systems are communicated. The essence for our...
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The lethal effect of hydrotechnical concrete on freshwater Bivalvia
PublikacjaMost hydrotechnical buildings under construction demand the concrete mixture to be set directly under water. The main reason for such a procedure is to limit the washing away of the the concrete binding mixture and to increase the efficiency of organisation of work so as to ensure continuity in concreting. The impact on the aquatic environment of recent developments in concrete technology and the use of new components has not yet...
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Estimators of covariance matrices in Msplit(q) estimation
PublikacjaThis paper proposes methods for the determination of covariance matrices of Msplit(q) estimators. The solutions presented here allow Msplit(q) estimation to be supplemented by the operations from the domain of accuracy analysis (especially that concerning estimators of parameters). Theoretical forms of covariance matrices of Msplit(q) estimators were established using the empirical influence functions and the equivalent covariance...
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Electrodes criticality: the impact of CRMs in the leachate electrochemical oxidation
Publikacja. Landfill leachate possesses high concentrations of ammonia, micropollutants, and heavy metals, and are characterised for low biodegradability. For this reason, conventional treatment technologies may result ineffective for complete pollutant removal. Electrochemical oxidation allows most of the of recalcitrant pollutants to be oxidised effectively within an easy operational and acceptable retention time, without the need to provide...
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High performance filtering for big datasets from Airborne Laser Scanning with CUDA technology
PublikacjaThere are many studies on the problems of processing big datasets provided by Airborne Laser Scanning (ALS). The processing of point clouds is often executed in stages or on the fragments of the measurement set. Therefore, solutions that enable the processing of the entire cloud at the same time in a simple, fast, efficient way are the subject of many researches. In this paper, authors propose to use General-Purpose computation...
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The history of Lake Rzecin and its surroundings drawn on maps as a background to palaeoecological reconstruction
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Grow first, gain fat in the meantime. Longitudinal study of anthropometric changes around menarche
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Elastic scattering of electrons from chloroform
PublikacjaWe present experimental and theoretical cross sections for elastic electron scattering from CHCl3. This is an important target because of its relevance to environmental chemistry and the plasma etching industry as a source of chlorine radicals. The experimental results were obtained at incident electron energies ranging from 0.5 to 800 eV in the 10deg-130deg scattering angle range. Theoretically, the scattering cross sections in...
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Entanglement of genuinely entangled subspaces and states: Exact, approximate, and numerical results
PublikacjaGenuinely entangled subspaces (GESs) are those subspaces of multipartite Hilbert spaces that consist only of genuinely multiparty entangled pure states. They are natural generalizations of the well-known notion of completely entangled subspaces, which by definition are void of fully product vectors. Entangled subspaces are an important tool of quantum information theory as they directly lead to constructions of entangled states,...
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Experimentally feasible semi-device-independent certification of four-outcome positive-operator-valued measurements
PublikacjaRecently the quantum information science community devoted a lot of attention to the theoretical and practical aspects of generalized measurements, the formalism of all possible quantum operations leading to acquisition of classical information. On the other hand, due to imperfections present in quantum devices, and limited thrust to them, a trend of formulating quantum information tasks in a semi-device-independent manner emerged....
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Quantum metrology: Heisenberg limit with bound entanglement
PublikacjaQuantum entanglement may provide a huge boost in the precision of parameter estimation. However, quantum metrology seems to be extremely sensitive to noise in the probe state. There is an important still open question: What type of entanglement is useful as a resource in quantum metrology? Here we raise this question in relation to entanglement distillation. We provide a counterintuitive example of a family of bound entangled states...
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Method for universal detection of two-photon polarization entanglement
PublikacjaDetecting and quantifying quantum entanglement of a given unknown state poses problems that are fundamentally important for quantum information processing. Surprisingly, no direct (i.e., without quantum tomography) universal experimental implementation of a necessary and sufficient test of entanglement has been designed even for a general two-qubit state. Here we propose an experimental method for detecting a collective universal...
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Magnetic-field-induced electric quadrupole moments for relativistic hydrogenlike atoms: Application of the Sturmian expansion of the generalized Dirac-Coulomb Green function
PublikacjaWe consider a Dirac one-electron atom placed in a weak, static, uniform magnetic field. We show that, to the first order in the strength of the external field, the only electric multipole moments, which are induced by the perturbation in the atom, are those of an even order. Using the Sturmian expansion of the generalized Dirac-Coulomb Green function we derive a closed-form expression for the electric quadrupole moment induced...
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Bound on Bell inequalities by fraction of determinism and reverse triangle inequality
PublikacjaIt is an established fact that entanglement is a resource. Sharing an entangled state leads to nonlocal correlations and to violations of Bell inequalities. Such nonlocal correlations illustrate the advantage of quantum resources over classical resources. In this paper, we quantitatively study Bell inequalities with 2 × n inputs. As found in Gisin et al. [Int. J. Quantum. Inform. 05, 525 (2007)], quantum mechanical correlations...
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Device-independent quantum key distribution based on measurement inputs
PublikacjaWe provide an analysis of a family of device-independent quantum key distribution (QKD) protocols that has the following features. (a) The bits used for the secret key do not come from the results of the measurements on an entangled state but from the choices of settings. (b) Instead of a single security parameter (a violation of some Bell inequality) a set of them is used to estimate the level of trust in the secrecy of the key....
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Distributed correlations and information flows within a hybrid multipartite quantum-classical system
PublikacjaUnderstanding the non-Markovian mechanisms underlying the revivals of quantum entanglement in the presence of classical environments is central in the theory of quantum information. Tentative interpretations have been given by either the role of the environment as a control device or the concept of hidden entanglement. We address this issue from an information-theoretic point of view. To this aim, we consider a paradigmatic tripartite...
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Quantum origins of objectivity
PublikacjaIn spite of all of its successes, quantum mechanics leaves us with a central problem: How does nature create a bridge from fragile quanta to the objective world of everyday experience? Here we find that a basic structure within quantum mechanics that leads to the perceived objectivity is a so-called spectrum broadcast structure. We uncover this based on minimal assumptions, without referring to any dynamical details or a concrete...
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Electron-scattering cross sections for selected alkyne molecules: Measurements and calculations
PublikacjaWe report cross-section results from experimental and theoretical studies on electron collisions with 1-butyne (HC≡C–CH2CH3) and acetylene (HC≡CH) molecules and from computations for a propyne (HC≡C–CH3) molecule. Absolute grand -total electron-scattering cross sections (TCSs) were measured at impact energies ranging from about 0.5 to 300 eV using the linear electron-transmission method. The TCS energy curve for 1-butyne has a...
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Electric-field-induced magnetic quadrupole moment in the ground state of the relativistic hydrogenlike atom: Application of the Sturmian expansion of the generalized Dirac-Coulomb Green function
PublikacjaStosując rozwinięcie sturmowskie uogólnionej funkcji Greena-Diraca-Coulomba, znaleziono wyrażenie analityczne dla magnetycznego momentu kwadrupolowego, indukowanego przez zewnętrzne słabe, stałe, jednorodne pole elektryczne w stanie podstawowym relatywistycznego atomujednoelektronowego.
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Long-distance quantum communication over noisy networks without long-time quantum memory
PublikacjaThe problem of sharing entanglement over large distances is crucial for implementations of quantum cryptography. A possible scheme for long-distance entanglement sharing and quantum communication exploits networks whose nodes share Einstein-Podolsky-Rosen (EPR) pairs. In Perseguers et al. [Phys. Rev. A 78, 062324 (2008)] the authors put forward an important isomorphism between storing quantum information in a dimension D and transmission...
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Sensitivity of entanglement decay of quantum-dot spin qubits to the external magnetic field
PublikacjaWe study the decay of entanglement of quantum-dot electron-spin qubits under hyperfine-interaction-mediated decoherence.We show that two-qubit entanglement of a single entangled initial state may exhibit decay characteristic of two disentanglement regimes in a single sample, when the externalmagnetic field is changed. The transition is manifested by the suppression of time-dependent entanglement oscillations which are superimposed...
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Free randomness amplification using bipartite chain correlations
PublikacjaA direct analysis of the task of randomness amplification from Santha-Vazirani sources using the violation of the chained Bell inequality is performed in terms of the convex combination of no-signaling boxes required to simulate quantum violation of the inequality. This analysis is used to find the exact threshold value of the initial randomness parameter from which perfect randomness can be extracted in the asymptotic limit of...
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Quantum-state transfer in spin chains via isolated resonance of terminal spins
PublikacjaWe propose a quantum-state transfer protocol in a spin chain that requires only the control of the spins at the ends of the quantum wire. The protocol is to a large extent insensitive to inhomogeneity caused by local magnetic fields and perturbation of exchange couplings. Moreover, apart from the free evolution regime, it allows one to induce an adiabatic spin transfer, which provides the possibility of performing the transfer...
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Postulates for measures of genuine multipartite correlations
PublikacjaA lot of research has been done on multipartite correlations. However, it seems strange thatthere is no denition of so called genuine multipartite correlations. In this paper we propose threereasonable postulates which each measure or indicator of genuine multipartite correlations (or gen-uine multipartite entanglement) should satisfy. We also introduce degree of correlations which givespartial characterization of multipartite...
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Magnetic field-induced electric quadrupole moment in the ground state of the relativistic hydrogen-like atom: Application of the Sturmian expansion of the generalized Dirac-Coulomb Green function
PublikacjaStosując rozwinięcie sturmowskie funkcji Greena-Diraca-Coulomba, znaleziono wyrażenie analityczne dla elektrycznego momentu kwadrupolowego, indukowanego przez zewnętrzne pole magnetyczne w relatywistycznym atomie wodoropodobnym w stanie podstawowym. Wykazano, że jest to efekt czysto relatywistyczny.
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Selected anionic and cationic surface active agents: case study on the Kłodnica sediments
PublikacjaSurface active agents (surfactants) are a group of chemical compounds, which are used as ingredients of detergents, cleaning products, cosmetics and functional products. After use, wastes containing surfactants or their degradation products are discharged to wastewater treatment plants or directly into surface waters. Due to their specific properties of SAAs, compounds are able to migrate between different environmental compartments...
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The potential of Web-GIS and geovisual analytics in the context of marine cadastre
PublikacjaThe importance of the marine environment to human existence makes it imperative that information models represent the multidimensional nature of reality as closely as possible in order to facilitate good governance. Information regarding jurisdiction, as well as the effects of formal law and community interests on the marine environment (e.g. nature and spatial extents as well as rights, responsibilities, restrictions etc.) would...
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The impact of the Tri-City Ring Road on surface water of small endorheic wetlands
PublikacjaThe paper presents the results of the impact of the Tri-City Ring Road on small endorheic catchment basins. Particular attention was paid to pollution discharged from the road to the surface water, as well as changes in hydrological conditions in the vicinity of the road. In the study, surface water samples were analysed in terms of their electrolytic conductivity, pH and content of major minerals. GIS was also used to study transformation...
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Information content of systems as a physical principle
PublikacjaTo explain the conceptual gap between classical and quantum and other, hypothetical descriptions of the world, several principles have been proposed. So far, all these principles have not explicitly included the uncertainty relation. Here we introduce an information content principle ( ICP ) which represents a constrained uncertainty principle. The principle, by taking into account the encoding and decoding properties of a single physical...
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Generic appearance of objective results in quantum measurements
PublikacjaMeasurement is of central interest in quantum mechanics as it provides the link between the quantum world and the world of everyday experience. One of the features of everyday experience is its robust, objective character, contrasting the delicate nature of quantum systems. Here we analyze in a completely model-independent way the celebrated von Neumann measurement process, using recent techniques of information flow, studied in...
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Redundant information encoding in QED during decoherence
PublikacjaBroadly understood decoherence processes in quantum electrodynamics, induced by neglecting either the radiation [L. Landau, Z. Phys. 45, 430 (1927)] or the charged matter [N. Bohr and L. Rosenfeld, K. Danske Vidensk. Selsk, Math.-Fys. Medd. XII, 8 (1933)], have been studied from the dawn of the theory. However, what happens in between, when a part of the radiation may be observed, as is the case in many real-life situations, has...
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Surfactants: a real threat to the aquatic geoecosystems of lobelia lakes
PublikacjaLobelia lakes are valuable elements of the natural environment. They are characterised by low trophy, mainly in-forest location and a high transparency of water. However, similarly to other surface waters, they are subjected to increasing anthropogenic pressures, a good indicator of which is the level of surfactants, also called surface-active agents (SAAs). The aim of the study was to evaluate the intensity of anthropogenic pressures...
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Computed vibrational excitation ofCF4by low-energy electrons and positrons: Comparing calculations and experiments
PublikacjaQuantum calculations for the excitation of the asymmetric modes of the CF4 target gas, ν3 and ν4, by impact of low-energy electrons and positrons are carried out in the energy range around 1 eV and are compared with recent experimental findings. The similarities and differences between the two types of projectiles, and the two different modes, are analyzed and discussed vis à vis the present accord with the experimental results.
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Schemes of transmission of classical information via quantum channels with many senders: Discrete- and continuous-variable cases
PublikacjaSuperadditivity effects in the classical capacity of discrete multiaccess channels and continuous variable (CV) Gaussian MACs are analyzed. Several examples of the manifestation of superadditivity in the discrete case are provided, including, in particular, a channel which is fully symmetric with respect to all senders. Furthermore, we consider a class of channels for which input entanglement across more than two copies of the...
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Subadditivity of the minimum output entropy and superactivation of the classical capacity of quantum multiple access channels
PublikacjaWe study subadditivity of the minimum output entropy (Hmin) of quantum multiple access channels (MACs). We provide an example of violation of the additivity theorem for Hmin known in classical information theory. Our result is based on a fundamental property of MACs, i.e., independence of each sender. The channels used in the example can be constructed explicitly. On the basis of subadditivity of Hmin we also provide an example...
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Directed percolation effects emerging from superadditivity of quantum networks
PublikacjaEntanglement-induced nonadditivity of classical communication capacity in networks consisting of quantum channels is considered. Communication lattices consisting of butterfly-type entanglement-breaking channels augmented, with some probability, by identity channels are analyzed. The capacity superadditivity in the network is manifested in directed correlated bond percolation which we consider in two flavors: simply directed and...
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Elastic electron scattering and vibrational excitation of isoxazole molecules in the energy range from 2 to 20 eV
PublikacjaDifferential cross sections for elastic electron scattering and the excitation of the C-H vibrational modes of isoxazole molecules were measured in the energy range from 2 to 20 eV and over the scattering angle range from 10◦ to 180◦. The cross sections at the scattering angles of and above 90◦ were accessible with the use of a magnetic angle changer. The differential cross sections were integrated to yield integral and momentum...
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Positron binding to alkali-metal hydrides: The role of molecular vibrations
PublikacjaThe bound vibrational levels for J=0 have been computed for the series of alkali-metal hydride molecules from LiH to RbH, including NaH and KH. For all four molecules the corresponding potential-energy curves have been obtained for each isolated species and for its positron-bound complex (e+XH). It is found that the calculated positron affinity values strongly depend on the molecular vibrational state for which they are obtained...
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Time-of-flight electron scattering from molecular hydrogen: Benchmark cross sections for excitation of the X1Σ+g→b3Σ+u transition
PublikacjaThe electron impact X1Σ+g to b3Σ+u transition in molecular hydrogen is one of the most important dissociation pathways to forming atomic hydrogen atoms, and is of great importance in modeling astrophysical and industrial plasmas where molecular hydrogen is a substantial constituent. Recently it has been found that the convergent close-coupling (CCC) cross sections of Zammit et al. [Phys. Rev. A 95, 022708 (2017)] are up to a factor...
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Reduction of measurement data before Digital Terrain Model generation vs. DTM generalisation
PublikacjaModern data acquisition technologies provide large datasets that are not always necessary in its entirety to properly accomplish the goal of the study. In addition, such datasets are often cumbersome for rational processing, and their processing is time and labour consuming. Therefore, methods that enable to reduce the size of the measurement dataset, such as the generalization of the Digital Terrain Model (DTM) or the reduction...
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Constructing genuinely entangled multipartite states with applications to local hidden variables and local hidden states models
PublikacjaBuilding upon the results of R. Augusiak et al. [Phys. Rev. Lett. 115, 030404 (2015)] we develop a general approach to the generation of genuinely entangled multipartite states of any number of parties from genuinely entangled states of a fixed number of parties, in particular, the bipartite entangled ones. In our approach, certain isometries whose output subspaces are either symmetric or genuinely entangled in some multipartite...
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Static magnetic multipole susceptibilities of the relativistic hydrogenlike atom in the ground state: Application of the Sturmian expansion of the generalized Dirac-Coulomb Green function
PublikacjaWe study far- and near-field magnetic and electric multipole moments induced in the ground state of the Dirac one-electron atom placed in a weak 2L-pole magnetostatic field. The analysis is carried out within the framework of the first-order Rayleigh-Schrödinger perturbation theory, with the use of the Sturmian expansion of the generalized Dirac-Coulomb Green function [Szmytkowski, J. Phys. B 30, 825 (1997);J. Phys. B 30, 2747(E)...
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From unextendible product bases to genuinely entangled subspaces
PublikacjaUnextendible product bases (UPBs) are interesting mathematical objects arising in composite Hilbert spaces that have found various applications in quantum information theory, for instance in a construction of bound entangled states or Bell inequalities without quantum violation. They are closely related to another important notion, completely entangled subspaces (CESs), which are those that do not contain any fully separable pure...
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Trade-offs in multiparty Bell-inequality violations in qubit networks
PublikacjaTwo overlapping bipartite binary input Bell inequalities cannot be simultaneously violated as this would contradict the usual no-signalling principle. This property is known as monogamy of Bell inequality violations and generally Bell monogamy relations refer to trade-offs between simultaneous violations of multiple inequalities. It turns out that multipartite Bell inequalities admit weaker forms of monogamies that allow for violations...
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System information propagation for composite structures
PublikacjaWe study in details decoherence process of a spin register, coupled to a spin environment. We use recently developed methods of information transfer study in open quantum systems to analyze information flow between the register and its environment. We show that there are regimes when not only the register decoheres effectively to a classical bit string, but this bit string is redundantly encoded in the environment, making it available...
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Second-order Stark effect and polarizability of a relativistic two-dimensional hydrogenlike atom in the ground state
PublikacjaThe second-order Stark effect for a planar Dirac one-electron atom in the ground state is analyzed within the framework of the Rayleigh-Schrödinger perturbation theory, with the use of the Sturmian series expansion of the generalized Dirac-Coulomb Green's function. A closed-form analytical expression for the static dipole polarizability of that system is found. The formula involves the generalized hypergeometric function ${}_{3}F_{2}$...
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Quantum superadditivity in linear optics networks: Sending bits via multiple-access Gaussian channels
PublikacjaSuperadditivity effects of communication capacities are known in the case of discrete variable quantum channels. We describe the continuous variable analog of one of these effects in the framework of Gaussian multiple access channels (MACs). Classically, superadditivity-type effects are strongly restricted: For example, adding resources to one sender is never advantageous to other senders in sending their respective information...
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Photofragmentation of tetrahydrofuran molecules in the vacuum-ultraviolet region via superexcited states studied by fluorescence spectroscopy
PublikacjaPhotofragmentation of tetrahydrofuran molecules in the vacuum-ultraviolet region, producing excited atomic and molecular fragments, has been studied over the energy range 14-68 eV using photon-induced fluorescence spectroscopy. Excited hydrogen atoms H(n), n = 3-11, have been detected by observation of the Hα to Hı lines of the Balmer series. The diatomic CH(A2Δ), CH(B2Σ-) and C2(d3Πg) fragments, which are excited to low vibrational...