Although persistent room‐temperature phosphorescence (RTP) emission has been observed for a few pure crystalline organic molecules, there is no consistent mechanism and no universal design strategy ...for organic persistent RTP (pRTP) materials. A new mechanism for pRTP is presented, based on combining the advantages of different excited‐state configurations in coupled intermolecular units, which may be applicable to a wide range of organic molecules. By following this mechanism, we have developed a successful design strategy to obtain bright pRTP by utilizing a heavy halogen atom to further increase the intersystem crossing rate of the coupled units. RTP with a remarkably long lifetime of 0.28 s and a very high quantum efficiency of 5 % was thus obtained under ambient conditions. This strategy represents an important step in the understanding of organic pRTP emission.
Persistence pays off: Bright persistent room‐temperature phosphorescence from pure organic molecules was achieved by intermolecular electronic coupling of selected units in crystals. The combined advantages of their different excited‐state configurations (i.e., the nπ* state with a high intersystem crossing rate and the ππ* state with a low radiative rate) results in a hybrid intersystem‐crossing process that leads to efficient persistent room‐temperature phosphorescence.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Imbalanced data is characterized by the severe difference in observation frequency between classes and has received a lot of attention in data mining research. The prediction performances usually ...deteriorate as classifiers learn from imbalanced data, as most classifiers assume the class distribution is balanced or the costs for different types of classification errors are equal. Although several methods have been devised to deal with imbalance problems, it is still difficult to generalize those methods to achieve stable improvement in most cases. In this study, we propose a novel framework called model-based synthetic sampling (MBS) to cope with imbalance problems, in which we integrate modeling and sampling techniques to generate synthetic data. The key idea behind the proposed method is to use regression models to capture the relationship between features and to consider data diversity in the process of data generation. We conduct experiments on 13 datasets and compare the proposed method with 10 methods. The experimental results indicate that the proposed method is not only comparative but also stable. We also provide detailed investigations and visualizations of the proposed method to empirically demonstrate why it could generate good data samples.
The creation of three‐dimensional (3D) structures from two‐dimensional (2D) nanomaterial building blocks enables novel chemical, mechanical or physical functionalities that cannot be realized with ...planar thin films or in bulk materials. Here, we review the use of emerging 2D materials to create complex out‐of‐plane surface topographies and 3D material architectures. We focus on recent approaches that yield periodic textures or patterns, and present four techniques as case studies: (i) wrinkling and crumpling of planar sheets, (ii) encapsulation by crumpled nanosheet shells, (iii) origami folding and kirigami cutting to create programmed curvature, and (iv) 3D printing of 2D material suspensions. Work to date in this field has primarily used graphene and graphene oxide as the 2D building blocks, and we consider how these unconventional approaches may be extended to alternative 2D materials and their heterostructures. Taken together, these emerging patterning and texturing techniques represent an intriguing alternative to conventional materials synthesis and processing methods, and are expected to contribute to the development of new composites, stretchable electronics, energy storage devices, chemical barriers, and biomaterials.
Emerging approaches to fabrication of 3D architectures are discussed, emphasizing creation of textural patterns by directed assembly of nanosheet building blocks: i) wrinkling and crumpling of 2D material films; ii) wrapping and crumpling of 2D materials around curved objects; iii) folding (origami) and cutting (kirigami) using 2D materials; and iv) 3D printing from 2D nanosheet suspensions.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The structural dynamics of a machine tool exhibit position-dependent behavior under operation due to the kinematic reconfiguration of its feed drives. Experimental identification of ...position-dependent dynamics can be time-consuming, and simulation models may lack accuracy due to modeling uncertainties. In this paper, the prediction of a machine tool's position-dependency is approached under the progressive network, a transfer learning technique to bridge the gap between the simulation and real-world domains. The dynamics simulation model may be somewhat inaccurate, but still describes a machine tool's overall position-dependency. The real-world domain is then characterized by sparse dynamics measurements made on the real machine tool. Under the progressive network architecture, a neural network is first trained in the simulation domain to extract valuable prior knowledge about the machine's position-dependency. A second network posed in the real-world domain then accesses such prior knowledge from the simulation domain via lateral connections to improve its dynamics predictions. Such transfer learning methodology may be most advantageous when the number of experimental data is limited, and the machine is unavailable for further testing due to production purposes. The proposed methodology was validated under numerical and experimental studies.
•Position-dependent structural dynamics of a five-axis machine tool is demonstrated.•A data-driven approach for the prediction of machine tool dynamics is proposed.•Improved prediction accuracy using a simulation model and transfer learning.•Proposed data-driven approach is experimentally validated.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Since its discovery, there has been a debate in the past few decades on the origin of the bimodal color distribution of Centaurs. Two theories have been proposed to explain this bimodal color ...distribution: (1) evolutionary processes resulting in changes of the surface properties of Centaurs, and (2) compositional differences inherited from the source region of Centaurs. Interestingly, Centaurs also show a correlation between their orbital inclinations and colors such that blue and red Centaurs tend to be characterized by high and low inclination distributions, respectively. In this study, these two hypotheses are investigated, and it is found that hypothesis (2) is more likely to be the origin of the color-inclination relation of Centaurs assuming that the scattered Kuiper Belt objects (SKBOs) also have a color-inclination relation, and this relation is statistically preserved when they evolved into Centaurs. This hypothesis is further justified by performing numerical simulations on 158 observed Centaurs and 82 observed SKBOs. Finally, it is suggested that the "outside-in" external photoevaporation happening during the early stage of the solar system might be related to the puzzling color-inclination relation observed in Centaurs and, possibly, other trans-Neptunian object subgroups.
Taiwan's music festival landscape has blossomed, attracting global music enthusiasts with its cultural richness and diverse offerings. Using structural equation modeling (SEM), a survey of ...festival-goers revealed the intricate relationships among factors like skill performance, self-congruence, ambiance, and consumer interaction, shaping authenticity, satisfaction, destination loyalty, and behavioral intentions. Interestingly, memory was identified as a moderating role, which interlinking satisfaction, behavioral intentions, and destination loyalty. These findings provide both theoretical insights and practical strategies for enhancing festival experiences and cultivating destination loyalty within Taiwan's thriving music scene.
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BFBNIB, NUK, PILJ, SAZU, UL, UM, UPUK
Thrombospondin‐1 (TSP1) is involved in corneal wound healing caused by chemical injury. Herein, we examined the effects of TSP1 on hypoxia‐induced damages and wound‐healing activity in human corneal ...epithelial (HCE) cells. Exosomal protein expression was determined using liquid chromatography‐tandem mass spectrometry, and HCE cell migration and motility were examined through wound‐healing assay and time‐lapse microscopy. Reestablishment of cell junctions by TSP1 was assessed through confocal microscopy and 3D image reconstruction. Our results show that CoCl2‐induced hypoxia promoted HCE cell death by paraptosis. TSP1 protected these cells against paraptosis by attenuating mitochondrial membrane potential depletion, swelling and dilation of endoplasmic reticulum and mitochondria, and mitochondrial fission. Exosomes isolated from HCE cells treated with TSP1 contained wound healing‐associated proteins that were taken up by HCE cells to promote tissue remodeling and repair. TSP1 protected HCE cells against hypoxia‐induced damages and inhibited paraptosis progression by promoting cell migration, cell‐cell adhesion, and extracellular matrix remodeling. These findings indicate that TSP1 ameliorates hypoxia‐induced paraptosis in HCE cells and promotes wound healing and remodeling by regulating exosomal protein expression. TSP1 may, therefore, play important roles in the treatment of hypoxia‐associated corneal diseases.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The prevalence of mitral valve prolapse (MVP) among middle- and older-aged individuals is estimated to be 2-4% in Western countries. However, few studies have been conducted among Asian individuals ...and young adults. This study included a sample of 2442 consecutive military adults aged 18-39 years in Hualien, Taiwan. MVP was defined as displacement of the anterior or posterior leaflet of the mitral valve to the mid portion of the annular hinge point > 2 mm in the parasternal long-axis view of echocardiography. Cardiac chamber size and wall thickness were measured based on the latest criteria of the American Society of Echocardiography. The clinical features of participants with MVP and those without MVP were compared using a two-sample t test, and the cardiac structures were compared using analysis of covariance with adjustment for body surface area (BSA). Eighty-two participants were diagnosed with MVP, and the prevalence was 3.36% in the overall population. Compared with those without MVP, participants with MVP had a lower body mass index (kg/m
) (24.89 ± 3.70 vs. 23.91 ± 3.45, p = 0.02) and higher prevalence of somatic symptoms related to exercise (11.0% vs. 4.9%, p = 0.02) and systolic click in auscultation (18.3% vs. 0.6%, p < 0.01). In addition, participants with MVP had greater left ventricular mass (gm) and smaller right ventricular wall thickness (mm) and dimensions (mm) indexed by BSA than those without MVP (149.12 ± 35.76 vs. 155.38 ± 36.26; 4.66 ± 0.63 vs. 4.40 ± 0.68; 26.57 ± 3.99 vs. 25.41 ± 4.35, respectively, all p-values < 0.01). In conclusion, the prevalence and clinical features of MVP in military young adults in Taiwan were in line with those in Western countries. Whether the novel MVP phenotype found in this study has any pathological meaning needs further investigation.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
ABSTRACT
NASA sent the Double Asteroid Redirection Test (DART) mission to impact Dimorphos, the satellite of the asteroid binary system (65803) Didymos. DART will release LICIACube prior to impact to ...obtain high-resolution post-impact images. The impact will produce a crater and a large amount of material ejected at high speed (several tens of m s−1), producing an ejecta cone that will quickly disperse. We analysed an additional effect: the lofting of material at low velocity due to the generation of seismic waves that propagate inside Dimorphos, producing surface shaking far from the impact point. We divide the process into different stages: from the generation of impact-induced waves, the interaction of them with surface particles, the ejection of dust particles at velocities, and the prediction of the observability of the dust coma and trail. We anticipate the following observable effects: (i) generation of a dust cloud that will produce a hazy appearance of Dimorphos’ surface, detectable by LICIACube; (ii) brightness increase of the binary system due to enhancement of the cross-section produced by the dust cloud; (iii) generation of a dust trail, similar to those observed in some Active Asteroids, which can last for several weeks after impact. Numerical prediction of the detectability of these effects depends on the amount and size distribution of ejected particles, which are largely unknown. In case these effects are observable, an inversion method can be applied to compute the amount of ejected material and its velocity distribution, and discuss the relevance of the shaking process.
ABSTRACT
The Double Asteroid Redirection Test (DART) is a NASA mission intended to crash a projectile on Dimorphos, the secondary component of the binary (65803) Didymos system, to study its orbit ...deflection. As a consequence of the impact, a dust cloud will be be ejected from the body, potentially forming a transient coma- or comet-like tail on the hours or days following the impact, which might be observed using ground-based instrumentation. Based on the mass and speed of the impactor, and using known scaling laws, the total mass ejected can be roughly estimated. Then, with the aim to provide approximate expected brightness levels of the coma and tail extent and morphology, we have propagated the orbits of the particles ejected by integrating their equation of motion, and have used a Monte Carlo approach to study the evolution of the coma and tail brightness. For typical power-law particle size distribution of index –3.5, with radii rrmin = 1 μm and rmax = 1 cm, and ejection speeds near 10 times the escape velocity of Dimorphos, we predict an increase of brightness of ∼3 magnitudes right after the impact, and a decay to pre-impact levels some 10 d after. That would be the case if the prevailing ejection mechanism comes from the impact-induced seismic wave. However, if most of the ejecta is released at speeds of the order of ≳100 m s−1, the observability of the event would reduce to a very short time span, of the order of 1 d or shorter.
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