Toward promising candidates of quantum information processing, the rapid development of lanthanide-based single-molecule magnets (Ln-SMMs) highlights design strategies in consideration of the local ...symmetry of lanthanide ions. In this review, crystal-field theory is employed to demonstrate the electronic structures according to the semiquantitative electrostatic model. Then, specific symmetry elements are analysed for the elimination of transverse crystal fields and quantum tunnelling of magnetization (QTM). In this way, high-performance Ln-SMMs can be designed to enable extremely slow relaxation of magnetization, namely magnetic blocking; however, their practical magnetic characterization becomes increasingly challenging. Therefore, we will attempt to interpret the experimental behaviours and clarify some issues in detail. Finally, representative Ln-SMMs with specific local symmetries are summarized in combination with the discussion on the symmetry strategies, and some of the underlying questions are put forward.
Based on crystal-field theory, design strategies in consideration of local symmetry are highlighted for lanthanide-based single-molecule magnets, accompanied by practical concerns about magnetic studies and representative cases.
BEST implements a Bayesian hierarchical model to jointly estimate gene trees and the species tree from multilocus sequences. It provides a new option for estimating species phylogenies within the ...popular Bayesian phylogenetic program MrBayes. The technique of simulated annealing is adopted along with Metropolis coupling as performed in MrBayes to improve the convergence rate of the Markov Chain Monte Carlo algorithm. Availability: http://www.stat.osu.edu/~dkp/BEST. Contact: lliu@oeb.harvard.edu
An extremely rare non‐Kramers holmium(III) single‐ion magnet (SIM) is reported to be stabilized in the pentagonal‐bipyramidal geometry by a phosphine oxide with a high energy barrier of 237(4) cm−1. ...The suppression of the quantum tunneling of magnetization (QTM) at zero field and the hyperfine structures originating from field‐induced QTMs can be observed even from the field‐dependent alternating‐current magnetic susceptibility in addition to single‐crystal hysteresis loops. These dramatic dynamics were attributed to the combination of the favorable crystal‐field environment and the hyperfine interactions arising from 165Ho (I=7/2) with a natural abundance of 100 %.
An extremely rare non‐Kramers holmium(III) single‐ion magnet is reported. The suppression of the quantum tunneling of magnetization at zero field and the hyperfine structures were observed in AC magnetic susceptibility measurements, and were attributed to the combination of a favorable crystal‐field environment and the hyperfine interactions arising from 165Ho (I=7/2) with a natural abundance of 100 %.
The successful joint observation of the gravitational wave (GW) event GW170817 and its multiwavelength electromagnetic counterparts enabled us to witness a definite merger event of two neutron stars ...(NSs) for the first time. This historical event confirms the origin of short-duration gamma-ray bursts (GRBs) and, in particular, identifies the theoretically predicted kilonova phenomenon that is powered by radioactive decays of r-process heavy elements. However, whether or not a long-lived remnant NS could be formed during this merger event remains unknown; though, such a central engine has been suggested by afterglow observations of some short-duration GRBs. By invoking this long-lived remnant NS, we propose a model of hybrid energy sources for the kilonova AT 2017gfo associated with GW170817. While the early emission of AT 2017gfo is still powered radioactively, as is usually suggested, its late emission is primarily caused by delayed energy injection from the remnant NS. In our model, only one single opacity is required and an intermediate value of κ 0.97 cm2 g−1 is revealed, which could be naturally provided by lanthanide-rich ejecta that are deeply ionized by the emission from a wind of the NS. These self-consistent results indicate that a long-lived remnant NS, which must have a very stiff equation of state, was formed during the merger event of GW170817. This provides a very stringent constraint on the strong interaction in nuclear-quark matter. It is further implied that such GW events could provide a probe of the early spin and magnetic evolutions of NSs, e.g., the burying of surface magnetic fields.
Methotrexate (MTX) is used as an anchor disease-modifying anti-rheumatic drugs (DMARDs) in treating rheumatoid arthritis (RA) because of its potent efficacy and tolerability. MTX benefits a large ...number of RA patients but partially suffered from side effects. A variety of side effects can be associated with MTX when treating RA patients, from mild to severe or discontinuation of the treatment. In this report, we reviewed the possible side effects that MTX might cause from the most common gastrointestinal toxicity effects to less frequent malignant diseases. In order to achieve regimen with less side effects, the administration of MTX with appropriate dose and a careful pretreatment inspection is necessary. Further investigations are required when combining MTX with other drugs so as to enhance the efficacy and reduce side effects at the same time. The management of MTX treatment is also discussed to provide strategies for occurred side effects. Thus, this review will provide scholars with a comprehensive understanding the side effects of MTX administration by RA patients.
Display omitted Risk factors of MTX induced side effects and their relationship.
•EULAR regarded Methotrexate as the first choice conventional synthetic DMARD for RA treatment.•RA patients who accept MTX therapy have different toxic reactions.•Measures could be taken to reduce MTX induced side effects.
The joint detection of GW170817 and GRB 170817A indicated that at least a fraction of short gamma-ray bursts (SGRBs) originate from binary neutron star (BNS) mergers. One possible remnant of a BNS ...merger is a rapidly rotating, strongly magnetized neutron star, which has been discussed as one possible central engine for gamma-ray bursts. For a rapidly rotating magnetar central engine, the deposition of the rotation energy into the ejecta launched from the merger could lead to bright radio emission. The brightness of radio emission years after an SGRB would provide an estimate of the kinetic energy of ejecta and, hence, a possible constraint on the BNS merger product. We perform a more detailed calculation on the brightness of radio emission from the interaction between the merger ejecta and circumburst medium in the magnetar scenario, invoking several important physical processes such as generic hydrodynamics, relativistic effects, and the deep Newtonian phase. We use the model to constrain the allowed parameter space for 15 SGRBs that have late radio observations. Our results show that an injection energy of Einj ∼ 1052 erg is allowed for all the cases, which suggests that the possibility of a supramassive or hypermassive neutron star remnant is not disfavored by the available radio data.
We study the non-leptonic two-body weak decays of Λc+(2286)→BnM with Bn (M) representing as the baryon (meson) states. Based on the SU(3) flavor symmetry, we can describe most of the data reexamined ...by the BESIII Collaboration with higher precisions. However, our result of B(Λc+→pπ0)=(5.6±1.5)×10−4 is larger than the current experimental limit of 3×10−4 (90% C.L.) by BESIII. In addition, we find that B(Λc+→Σ+K0)=(8.0±1.6)×10−4, B(Λc+→Σ+η′)=(1.0−0.8+1.6)×10−2, and B(Λc+→pη′)=(12.2−8.7+14.3)×10−4, which are accessible to the BESIII experiments.
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•Systematic summary of guest effects in spin-crossover Hofmann clathrates.•Molecular volume calculated by a convenient formula is applied to explore the size effect.•Strategies are ...discussed for optimizing the sensor property.
The incorporation of spin-crossover (SCO) properties into metal-organic frameworks (MOFs) is an appealing subclass of multifunctional MOFs with potential applications in molecular sensing. This review focuses on the design of SCO Hofmann-type MOFs, with emphasis on the guest effect on their SCO properties. The influences of guest size, dielectric constant, π⋯π interaction, hydrogen bonding interactions, weak X⋯M′ covalent bonding, and chemical reaction on the SCO properties of Hofmann-type MOFs are systematically explored. Further enhancements of sensing properties are also illustrated.
Single-molecule magnets (SMMs) that can be trapped in one of the bistable magnetic states separated by an energy barrier are among the most promising candidates for high-density information storage, ...quantum processing, and spintronics. To date, a considerable series of achievements have been made. However, the presence of fast quantum tunnelling of magnetization (QTM) in most SMMs, especially in single-ion magnets (SIMs), provides a rapid relaxation route and often sets up a limit for the relaxation time. Here, we pursue the pentagonal bipyramidal symmetry to suppress the QTM and present pentagonal bipyramidal Dy(III) SIMs Dy(Cy3PO)2(H2O)5Cl3·(Cy3PO)·H2O·EtOH (1) and Dy(Cy3PO)2(H2O)5Br3·2(Cy3PO)·2H2O·2EtOH (2), (Cy3PO = tricyclohexyl phosphine oxide). Magnetic characterizations reveal their fascinating SMM properties with high energy barriers as 472(7) K for 1 and 543(2) K for 2, along with a record magnetic hysteresis temperature up to 20 K for 2. These results, combined with the ab initio calculations, offer an illuminating insight into the vast possibility and potential of what the symmetry rules can achieve in molecular magnetism.
Time series classification is an important research topic in machine learning and data mining communities, since time series data exist in many application domains. Recent studies have shown that ...machine learning algorithms could benefit from good feature representation, explaining why deep learning has achieved breakthrough performance in many tasks. In deep learning, the convolutional neural network (CNN) is one of the most well-known approaches, since it incorporates feature learning and classification task in a unified network architecture. Although CNN has been successfully applied to image and text domains, it is still a challenge to apply CNN to time series data. This paper proposes a tensor scheme along with a novel deep learning architecture called multivariate convolutional neural network (MVCNN) for multivariate time series classification, in which the proposed architecture considers multivariate and lag-feature characteristics. We evaluate our proposed method with the prognostics and health management (PHM) 2015 challenge data, and compare with several algorithms. The experimental results indicate that the proposed method outperforms the other alternatives using the prediction score, which is the evaluation metric used by the PHM Society 2015 data challenge. Besides performance evaluation, we provide detailed analysis about the proposed method.
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