Exotic Nature Research Articles

On the occurrence of kalsilite in melilite-bearing ultrapotassic lavas from the Roman Province (Vulsini Mts., central Italy)

The Montefiascone Volcanic Complex belongs to the Vulsini Mts. volcanic district, one of the several leucite-bearing ultrapotassic Pleistocene volcanoes of the Roman Province (Central Italy). It is characterized by abundant pyroclastic successions and minor lava flows emplaced during a caldera formation phase occurred ∼0.3–0.2 Ma. The volcanic products span from leucite-basanites and leucite-tephrites to rarer leucitites and melilitites, occasionally associated with very rare kalsilite melilitolite ejecta. Here we report for the first time the presence of primary kalsilite in two lava flows in Forcinella and Feltricci localities, identifying a kamafugitic component among the Montefiascone volcanics.Detailed petrographic, SEM and EPMA studies on ten samples from the two localities revealed, in addition to kalsilite, variable amounts of clinopyroxene, melilite, leucite and nepheline plus rarer olivine coupled with carbonate-bearing segregation pockets in the groundmass. Geochemical and isotopic data confirm the exotic nature of the analysed rocks, showing ultrabasic/basic (SiO2 = 42.15–45.94 wt%) and ultrapotassic (K2O = 6.17–8.48 wt%; K2O/Na2O = 5.3–8.7) compositions, as well as strongly radiogenic 87Sr/86Sr (0.71038–0.711068), poorly radiogenic 143Nd/144Nd (0.512057.512091) and uniform middle radiogenic 206Pb/204Pb (18.76–18.78). Boron isotopes (δ11B ranges from 7.36 to 8.82‰) almost overlaps the typical MORB-OIB range values.These geochemical features recall those of the nearby kamafugite rocks from the Intra-Apennine Province. Major oxide and trace element modelling support fractionation links among the Italian kamafugite types. The overall geochemical and isotopic signatures speak for a common strongly subduction-metasomatized and orthopyroxene-free lithospheric mantle source. As already proposed for some nearby kamafugite centres in central Italy, limestone assimilation during magma ascent is a viable option to explain the mineralogical and whole-rock composition of Montefiascone lavas (i.e., the presence of carbonate plagues in the lava groundmass). This is particularly relevant considering the thick sedimentary sequence pierced by the limited volume of the upwelling magma. On the other hand, many other key features (such as the general lack of crustal xenoliths, the overall incompatible element fractionation and the radiogenic Sr isotopic ratios) clearly require also derivation from subduction-modified mantle sources.

Competitive superconductivity and charge density wave in Mo-doped kagome superconductor CsV3Sb5

In the kagome superconductors AV3Sb5 (A = K, Rb, Cs), understanding the charge-density-wave (CDW) state and its entanglement with the superconducting ground state is still a challenging issue. Here, by measuring the electrical transport, magnetic susceptibility, Hall effect, and V51 nuclear magnetic resonance (NMR), the evolution of superconductivity (SC) and the CDW is comprehensively studied in Cs(V1−xMox)3Sb5. In contrast with previously reported results for other doped cases, the CDW transition temperature slightly increases to ∼100 K with increasing Mo doping. Meanwhile, the SC is quickly suppressed and vanishes above x=0.02. The anomalous Hall effect (AHE), which is tied to the exotic nature of the CDW state in pristine CsV3Sb5, is also strongly suppressed and completely disappears above x=0.07. Further V51 NMR investigation on the CDW state in Cs(V0.95Mo0.05)3Sb5 indicates that a short-range stripelike CDW evolves from the original triple-Q CDW state with increasing Mo doping, which largely reduces the density of states at the Fermi level. This result provides a self-consistent explanation for the disappearance of both SC and the AHE by increasing Mo doping, which offers insights into the competitive behavior between SC and the CDW state in the kagome superconductors AV3Sb5. Published by the American Physical Society 2024

Constituent model of light hybrid meson decays

A model of light hybrid mesons and their strong decays is developed. The model employs a gluonic quasiparticle to describe low energy gluodynamics and uses the QCD Hamiltonian in Coulomb gauge to guide the construction of states and decay amplitudes. We compute the partial widths of the twelve low lying isovector and vector hybrids. Implications of these results on hybrid searches are also made, with the chief conclusions being that direct observation of the vector states will be difficult, that a hybrid π(1800) has distinctive decay characteristics, a narrow η(1900) hybrid should exist, an η1(1750) should be sought, and that the exotic nature of JPC=2−+ hybrid mesons should be discernible with sufficient data. We argue that the isovector π2 hybrid has been discovered, giving a total of four possible hybrid mesons, π1(1600), η1(1855), π(1800), and π2(2360), which appear to be filling out the low lying hybrid supermultiplet in the expected fashion. Published by the American Physical Society 2024

Electric‐Field‐Induced in‐Plane Anisotropy of Superconducting Transition Temperature for FeSe0.5Te0.5 Thin Films

AbstractSuperconductor/ferroelectric heterostructures are very important for fundamental research and applications since superconductivity can be controlled by electric fields via ferroelectric polarization/piezostrain. Superconductivity is a macroscopic quantum phenomenon and it is commonly believed that the in‐plane superconducting transition temperature (Tc) should be isotropic for superconductors with crystal structures of stacking layers (quasi 2D). Here, the observation of piezostrain‐induced in‐plane anisotropy of Tc in FeSe0.5Te0.5 (FST) thin films grown on ferroelectric single crystals is reported. The as‐prepared FST shows a tetragonal phase with equal in‐plane lattice parameters and an absence of in‐plane anisotropy of Tc. Upon applying electric fields, piezostrain induces a difference in the in‐plane lattice parameters (a‐b) and in‐plane anisotropy of Tc. The in‐plane anisotropy of Tc correlates with a‐b and becomes more remarkable for larger values of a‐b. Some possible extrinsic effects are ruled out by experiments and analysis. A possible mechanism is proposed involving electronic nematicity and inhomogeneous superconductivity in FST to account for this unusual phenomenon. This work is significant for uncovering the exotic nature of unconventional superconductors, as well as applications.

Little rip, pseudo rip and bounce cosmology with generalized equation of state in non-standard backgrounds

The discovery of universe’s late-time acceleration and dark energy has overseen a great deal of research into cosmological singularities and particularly future singularities. Perhaps the most extreme of such singlarities is the big rip, which has propelled a lot of work into ways of moderating it or seeking out alternatives to it and two such alternatives to the big rip are the Little rip and Pseudo rip. Another possibility to consider the far future of the universe is through bounce cosmologies, which presents its own interesting ideas. So in this work we investigate the Little rip, Pseudo rip and Bounce cosmology in non-standard cosmological backgrounds with a generalized equation of state in the presence of a viscous fluid. In particular we discuss about Chern-Simons cosmology and the RS-II Braneworld and discuss how the exotic and non-conventional nature of gravity in such cosmologies affect universal evolution in these scenarios. We find out that there are very significant differences in the behaviour of such cosmic scenarios in these universes in comparison to how they appear in the simple general relativistic universe.

Influence of light neutron-rich exotic nuclei in deciding abundance patterns relevant for explosive nucleosynthesis

Exotic neutron-rich nuclei play an important role in r-process nucleosynthesis. We study the effect of including proper nuclear structure to calculate neutron capture and photodisintegration rates, especially for 19C and 20N, under the aegis of post-form distorted wave Born approximation (FRDWBA). Considering a network of neutron-rich C–N–O isotopes, we show the effect on abundance calculations in a neutrino-driven wind environment of a core-collapse supernova at two critical temperatures T 9 = 3.4 and 0.62. The results are compared for nuclear physics inputs sourced from the FRDWBA, statistical estimates, and standard databases. At temperatures T 9 = 3.4, where alpha capture, or at T 9 = 0.62, where the neutron capture dominates, one can distinguish the effect of accounting for the exotic nature of the nuclei involved. Furthermore, we assess the impact of varying neutron capture and photodisintegration rates involving halo or bubble structures on the abundances within the network.

Recent Highlights on Meson Spectroscopy at BESIII

Despite mesons being one of the longest known type of particles, there are still many open questions. Besides well understood states that can be clearly attributed to meson nonets, there are many candidates which could have an exotic nature instead. Such exotic particles e.g. glueballs, hybrids and tetraquarks can be favorably studied in clean, gluon rich environments. The BE-SIII experiment, which is in operation at the BEPCII electron-positron collider in Beijing since 2009, has collected world leading high statistic data samples in the charmonium region. This allows to study rare reactions that are considered to be suppressed. This offers unique possibilities to study exotic QCD states in the charmonium sector, but also the light meson spectrum which can be ac cessed via charmonium decays. Especially radiative J/ψ decays offer a gluon rich environment in which glueballs and hybrid states can be expected. Since these states are often hard to identify and disentangle, partial wave analysis are needed to determine the different contributions.

Local work function on graphene nanoribbons.

Graphene nanoribbons show exciting electronic properties related to the exotic nature of the charge carriers and to local confinement as well as atomic-scale structural details. The local work function provides evidence for such structural, electronic, and chemical variations at surfaces. Kelvin prove force microscopy can be used to measure the local contact potential difference (LCPD) between a probe tip and a surface, related to the work function. Here we use this technique to map the LCPD of graphene nanoribbons grown on a Au(111) substrate. The LCPD data shows charge transfer between the graphene nanoribbons and the gold substrate. Our results are corroborated with density functional theory calculations, which verify that the maps reflect the doping of the nanoribbons. Our results help to understand the relation between atomic structure and electronic properties both in high-resolution images and in the distance dependence of the LCPD.

The importance of the Tulip Festival in the development of event tourism in Zhambyl region

Event tourism is extremely popular all over the world. Millions of sports fans, lovers of various festivals, admirers of outstanding artists travel around the planet to attend those events that meet their needs. In this regard, in order to attract inbound and domestic tourists, it is necessary to define regional brands of an exotic nature in the regions of Kazakhstan, on the basis of which it will be possible to develop event tourism. This article is devoted to the study of the significance of the tulip festival in the Zhambyl region for the development of event tourism. Particular attention is paid to the study of the diversity of wild tulip varieties in their natural habitat, attracting tourists and researchers not only from Kazakhstan, but also from all over the world. The influence of the festival on attracting the attention of the world community to the problem of preserving biodiversity in the Central Asian region is analyzed. It is concluded that it is wild tulips that can become a regional tourism brand of the republic, various festivals will contribute to the sustainable growth of tourism and the economy of the region, and the development of event tourism will give impetus to the revival of the intangible cultural heritage of the country.

Semantics of Louis Durey’s vocal-instrumental cycle “Songs on Saint Léger Léger’s poems” (“Images à Crusoé”)

Statement of the problem. The article aims to investigate the semantics of the vocal-instrumental cycle “Songs on Saint Léger Léger’s poems” by Louis Edmond Durey (1888–1979), one of the representatives of the French “Group of Six”. This composition, which also has another name – “Images à Crusoé”, written in 1918, belongs to the period of formation of French modernism. The primary literary source, the poem of the same name by Alexis Saint Léger Léger, better known under the pseudonym Saint John Perce, has certain features of surrealistic aesthetics, which also influenced the musical dramaturgy of the cycle. Objectives, methods, and novelty of the research. Until today, this composition by Louis Durey has not been considered in domestic musicology, therefore, the task of the study is to describe the figurative sphere of the work, to identify its main intonation-semantic constructions and, ultimately, a more thorough explore of the individual style of the composer. The research was carried out using historical-contextual, comparative, and systemanalytical methods. Results and conclusion. According to his results, it was established that Louis Durey embodied not so much the content of Saint John Perce’s poetic stanzas as his personal attitude to his poetic images and metaphors. The composer operates with a whole semantic system of leit-intonemas and through- genre models (polka, lullaby, chorale, hymn) and builds semantic arches between numbers of the cycle. Cross-cutting musical and semantic elements also become components of arch dramaturgy: intonations of circles, “spindles”, bells, sighs, and the instrumental texture of all numbers of the cycle contains quarto-quint steps. Pentatonic, whole-tone and natural scales contribute to the reproduction of the atmosphere of the exotic nature of the deserted island, as well as the sound imaging techniques used by Durey. The dramaturgy of the cycle is built according to the montage principle, which is mostly subordinated to the type of verse and the semantic content of Saint John Perce’s poetry. Division of the musical form is carried out by changing the size, tempo, genre style. Thus, each number of the cycle consists of short sections connected to each other thanks to the collage technique. The rhythmic and thematic variety in the collage of episodes“frames” indicates the presence of game logic in L. Durey’s cycle. Certain influences on the music of the cycle of illustrations for Daniel Defoe’s novel “Robinson Crusoe”, created in the second half of the 19th century by Carl Offendinger, in perspective, allow us to consider the work in the context of the problem of the synthesis of arts as of a component of modernistic aesthetics.

Fictional and fictionalised religions as heritage? Reflections on the object of critical heritage studies

ABSTRACT This article attempts to make a connection between two fields, that usually operate in separate intellectual contexts: critical research on heritage as a social practice and the study of historical and fantasy fiction, concentrating on renditions of the Middle Ages. Both the construction of heritage and the creation of a fictional narrative are ways of processing of the past, although, at first sight, opposites. Claiming a site as heritage and therefore as determining a community’s identity elides the distance between past and present, whereas the authors of historical and fantasy fiction are keen to stress the exotic nature of the Middle Ages. Yet, the article argues that these practices operate on a sliding scale and asks the question whether the telling of a fictional tale about the Middle Ages might be a heritage practice in itself.

Closed-loop control of a noisy qubit with reinforcement learning

The exotic nature of quantum mechanics differentiates machine learning applications in the quantum realm from classical ones. Stream learning is a powerful approach that can be applied to extract knowledge continuously from quantum systems in a wide range of tasks. In this paper, we propose a deep reinforcement learning method that uses streaming data from a continuously measured qubit in the presence of detuning, dephasing, and relaxation. The model receives streaming quantum information for learning and decision-making, providing instant feedback on the quantum system. We also explore the agent’s adaptability to other quantum noise patterns through transfer learning. Our protocol offers insights into closed-loop quantum control, potentially advancing the development of quantum technologies.

Predictions of superexotic heavy mesons from K*B(*)B* interactions

We make a theoretical study of the three-body system composed of ${\bar K^*}{\bar B^*}{\bar B^*}$ to look for possible bound states, which could be associated to mesonic resonances of very exotic nature, containing open strange and double-bottom flavours. The three-body interaction is evaluated by using the fixed center approach to the Faddeev equations where the ${\bar B^*}{\bar B^*}$ is bound forming an $I(J^P)=0(1^+)$ state, as it was found in previous works, and the third particle, the ${\bar B^*}$, of much smaller mass, interacts with the components of the cluster. We obtain bound states for all the channels considered: spin $J=0$, 1 and 2, all of them with isospin $I=1/2$ and negative parity.

Photo- and electro-production of narrow exotic states: From light quarks to charm and up to bottom

Accessing a full image of the inner content of hadrons represents a central endeavour of modern particle physics, with the main scientific motivation to investigate the strong interaction binding the visible matter. On the one hand, the structure of known exotic candidates is a fundamental open issue addressed widely by scientists. On the other hand, looking for new states of exotic nature is a central component for theoretical and experimental efforts from electron-positron machine and electron accelerator with fixed target to heavy ion and electron-ion colliders. In this article we present a succinct short overview of the attempt to search for exotic narrow N* and Z states containing light quarks only or also charm, and its connotation for bottom regions (the latter two are also known as Pc (Zc) and Pb (Zb) states, respectively in the literature). We address the effort of searching for exotic narrow N* and Z states in light quark sector. We focus on recent progress in searching for signal of Pc and Zc states photoproduction and its implication into the Pb and Zb photoproduction and their decay properties. We also discuss future perspectives for the field in electron-ion colliders, a good place to disentangle the nature of some of these states and investigate some other enlightening topics including QCD trace anomaly and quarkonium-nucleon scattering length.

ПОВСЕДНЕВНАЯ ЭКЗОТИКА В ШКОЛЬНЫХ РИТОРИЧЕСКИХ УПРАЖНЕНИЯХ ДРЕВНЕГО РИМА (НА МАТЕРИАЛЕ "ВОСПИТАНИЯ ОРАТОРА" КВИНТИЛИАНА И "ДИАЛОГА ОБ ОРАТОРАХ" ТАЦИТА)

The article considers contexts from Quintilian (Quint. 3.6.96– 103; 7.8.3–6), Tacitus (Tac. dial. 35), and Juvenal (Iuv. 7.150–151) in order to show some features of the genre of Ancient school recitation and the typical images found in these exercises. At the same time, a criticism is made of the opinion widespread in the editions that some of these images (tyrants and tyrannicide) could be perceived as anti-monarchical and threatening to imperial power; two alleged cases of repressive actions of Roman emperors against specific rhetors are suggested to be regarded as excesses (and one of the cases can be considered unreliable at all); oppositional sentiments in Tacitus’ “Dialogue on Orators” are associated not with the genre of recitation at all, but with drama; Quintilian, loyal to Domitian, repeatedly uses examples of tasks with tyrants and tyrannicide as absolutely neutral. It is supposed to see in the exotic nature of the plots and characters the everyday need of school teachers to invent sufficiently complex conditions of rhetorical tasks to develop students’ abilities to find arguments. Thereto Quintilian actively applies the theory of statuses, an example of the use of which is given in the translation of previously unpublished fragments from the third book of “Institutes of Oratory”

Unraveling actinide-actinide bonding in fullerene cages: a DFT versus ab initio methodological study.

Actinide-actinide bonding poses a challenge for both experimental and theoretical chemists because of both the scarcity of experimental data and the exotic nature of actinide bonding due to the involvement and mixing of actinide 7s-, 6p-, 6d-, and particularly 5f-orbitals. Only a few experimental examples of An-An bonding have been reported so far. Here, we perform a methodological study of actinide-actinide bonding on experimentally known Th2@C80 and U2@C80 systems. We compared selected GGA, meta-GGA, hybrid-GGA and range-separated hybrid-GGA functionals with the results obtained using a multireference CASPT2 method, which we consider as a reference point. We show that functionals such as BP86, PBE or TPSS perform well for predicting geometries, while range-separated hybrids are superior in the description of the chemical bonding. None of the tested functionals were deemed reliable regarding the correct electronic spin ground state. Based on the results of this methodological study, we re-evaluate selected previously studied diactinide fullerene systems using more reliable protocol.

A virtual paradise? Platform algorithms, coastal change, and the production of nature in the Philippines

Across parts of Southeast Asia, coastal governance strategies have drawn on ‘ecotourism’ initiatives for ‘sustainable development’ by constructing captivating imaginaries of coastal places and people as sites of touristic production and consumption. Increasingly, representations of exotic and pristine coastal natures are reproduced virtually in support of this campaign through Web 2.0 platforms and their underlying algorithms. As ecotourism expands in the region, growing networks of social media users coproduce and consume abstract virtual natures with profound consequences for coastal peoples and ecosystems. In particular, Instagram, a popular photo sharing social media platform, has become central to reifying and distorting complex coastal realities. Drawing on a case from El Nido, Palawan Island, the Philippines, our paper examines how the virtual representation of coastal places and people on Instagram accelerate coastal transformations. Our results reveal how the political economy of coastal governance and the platform capitalism of social media converge to accelerate ecotourism in ways that realign virtual ideals and material realities. As virtual imaginaries shape coastal realities, new forms of exclusion and misrepresentation of people and places drive the displacement of local fishers, violence against activists, and coastal degradation. Bringing together research exploring (mass) ecotourism, platform capitalism and virtualism, we argue that greater scholarly attention should be placed on how new digital actors and platform algorithms influence how coastal peoples and places are imagined, consumed and subject to violence over time.

Detrital zircon similarities and dissimilarities between the Iberian Pyrite Belt, Ossa-Morena Zone and Meguma

Despite the so-called exotic nature of the South Portuguese Zone relatively to the other major domains of the Iberian Massif of peri-Gondwanan affinity, Devonian detrital rocks of the oldest strata in the Iberian Pyrite Belt have a remarkable resemblance with the Ossa-Morena Zone’s Neoproterozoic-Cambrian rocks and the West Meguma’s Cambrian-Ordovician rocks, presenting the so-called “West African signature”.

The Challenges of Translating Ḥāfiẓ into Russian

Abstract Despite the geographical proximity, the cultural and linguistic gaps between the Russian and the Persian languages are too many to enumerate. The Russian translator’s grasp of Islam and Middle Eastern culture at the end of the nineteenth and the beginning of the twentieth century was limited—and frequently Orientalist. While the “exotic nature” of Persian poetry and Ḥāfiẓ’s ghazals in particular evoked great interest among translators and readers, it was presented to the Russian literary circles mostly in the tradition of secular lyrical poetry and was not placed in its mystical or allegorical context. Below, by citing four ghazals and their translation nuances by four Russian poets, this article will examine the means by which Russian translators introduced a nuanced Persian lyrical poetry to their Russian audience.

Magnetic rare-earth ion mediated 4f-3d interlayer coupling and giant exchange bias in single layered Ruddlesden-Popper perovskites SrLnCo0.5Mn0.5O4 (Ln = Pr, Nd)

We report an in-depth study on exotic magnetic nature including giant exchange bias in single layered Ruddlesden-Popper structure polycrystalline perovskites SrRCo0.5Mn0.5O4 (R = Pr, and Nd). X-ray diffraction, neutron diffraction, and Raman spectroscopic studies on both compounds confirm tetragonal crystal structure with I4/mmm space group. Temperature evolution of dc magnetization and ac susceptibility show multiple magnetic phase transitions in both the compounds, i.e., high temperature ferromagnetic transition (Tc = 178/172 K) followed by antiferromagnetic transition at an intermediate temperature (TN = 90/100 K) and finally entering to a glassy magnetic state at lower temperatures (Tg = 35/25 K). Neutron powder diffraction confirms the absence of long-range magnetic order in both compounds. Atomically disordered (Co/Mn)O2 layers give rise to intralayer short range 3d-3d magnetic interactions resulting in co-existence of ferromagnetic and antiferromagnetic regions producing frozen magnetic state below Tg. Present experimental results and analysis show giant exchange bias of − 3.6/− 1.7 kOe (Pr/Nd systems) under cooling field of 50 kOe at 5 K, which stems from the inherent magnetic inhomogeneity. Our results reveal that magnetic rare-earth ion (Pr/Nd) induces a pathway of interlayer 4f-3d magnetic interactions leading to antiferromagnetic interaction between adjacent (Co/Mn)O2 layers, and this has a significant influence on the exchange bias values at low temperature.