2,602 research outputs found

    Effects of tidally enhanced stellar wind on the horizontal branch morphology of globular clusters

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    Metallicity is the first parameter to influence the horizontal branch (HB) morphology of globular clusters (GCs). It has been found, however, that some other parameters may also play an important role in affecting the morphology. While the nature of these important parameters remains unclear, they are believed to be likely correlated with wind mass-loss of red giants, since this mass loss determines their subsequent locations on the HB. Unfortunately, the mass loss during the red giant stages of the stellar evolution is poorly understood at present. The stellar winds of red giants may be tidally enhanced by companion stars if they are in binary systems. We investigate evolutionary consequences of red giants in binaries by including tidally enhanced stellar winds, and examine the effects on the HB morphology of GCs. We find that red, blue, and extreme horizontal branch stars are all produced under the effects of tidally enhanced stellar wind without any additional assumptions on the mass-loss dispersion. Furthermore, the horizontal branch morphology is found to be insensitive to the tidal enhancement parameter, Bw. We compare our theoretical results with the observed horizontal branch morphology of globular cluster NGC 2808, and find that the basic morphology of the horizontal branch can be well reproduced. The number of blue horizontal branch stars in our calculations, however, is lower than that of NGC 2808.Comment: 7 pages, 4 figures, 2 tables, accepted for publication in Astronomy & Astrophysic

    Dynamical study of the possible molecular state X(3872) with the s-channel one gluon exchange interaction

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    The recently observed X(3872) resonance, which is difficult to be assigned a conventional ccˉc\bar{c} charmonium state in the quark model, may be interpreted as a molecular state. Such a molecular state is a hidden flavor four quark state because of its charmonium-like quantum numbers. The s-channel one gluon exchange is an interaction which only acts in the hidden flavor multi-quark system. In this paper, we will study the X(3872) and other similiar hidden flavor molecular states in a quark model by taking into account of the s-channel one gluon exchange interaction

    Schramm-Loewner Equations Driven by Symmetric Stable Processes

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    We consider shape, size and regularity of the hulls of the chordal Schramm-Loewner evolution driven by a symmetric alpha-stable process. We obtain derivative estimates, show that the complements of the hulls are Hoelder domains, prove that the hulls have Hausdorff dimension 1, and show that the trace is right-continuous with left limits almost surely.Comment: 22 pages, 4 figure

    Target-oriented Sentiment Classification with Sequential Cross-modal Semantic Graph

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    Multi-modal aspect-based sentiment classification (MABSC) is task of classifying the sentiment of a target entity mentioned in a sentence and an image. However, previous methods failed to account for the fine-grained semantic association between the image and the text, which resulted in limited identification of fine-grained image aspects and opinions. To address these limitations, in this paper we propose a new approach called SeqCSG, which enhances the encoder-decoder sentiment classification framework using sequential cross-modal semantic graphs. SeqCSG utilizes image captions and scene graphs to extract both global and local fine-grained image information and considers them as elements of the cross-modal semantic graph along with tokens from tweets. The sequential cross-modal semantic graph is represented as a sequence with a multi-modal adjacency matrix indicating relationships between elements. Experimental results show that the approach outperforms existing methods and achieves state-of-the-art performance on two standard datasets. Further analysis has demonstrated that the model can implicitly learn the correlation between fine-grained information of the image and the text with the given target. Our code is available at https://github.com/zjukg/SeqCSG.Comment: ICANN 2023, https://github.com/zjukg/SeqCS

    Guiding optical flows by photonic crystal slabs made of dielectric cylinders

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    We investigate the electromagnetic propagation in two-dimensional photonic crystals, formed by parallel dielectric cylinders embedded a uniform medium. The frequency band structure is computed using the standard plane-wave expansion method, while the propagation and scattering of the electromagnetic waves are calculated by the multiple scattering theory. It is shown that within partial bandgaps, the waves tend to bend away from the forbidden directions. Such a property may render novel applications in manipulating optical flows. In addition, the relevance with the imaging by flat photonic crystal slabs will also be discussed.Comment: 5 pages, 5 figure

    Depression Involved in the Chemotherapy Induced Event-based Prospective Memory Impairment in Breast Cancer Survivors

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    The aim of this study was to investigate the relationships between depression and occurrence of chemotherapy induced prospective memory impairment in patients with breast cancer (BC).The 63 BC patients before and after chemotherapy were administered with the self-rating depression scale (SDS) and a battery of cognitive neuropsychological tests including event-based and time-based prospective memory (EBPM and TBPM, respectively) tasks. The changes in their prospective memory and cognitive neuropsychological characteristics before and after chemotherapy were compared. Compared with the scores before chemotherapy, the EBPM score exhibited a statistically significant difference after chemotherapy (t = 6.069, P 0.05). Further, compared with the patients without depression, the patients with depression exhibited a statistically significant difference in the EBPM score (t = -4.348, P 0.05). Post-chemotherapy, EBPM and overall cognitive functions in BC patients merged with depression were found to decline, while TBPM did not show a significant change, suggesting that the combination of chemotherapy and depression might be related with the occurrence of post-chemotherapy EBPM impairment

    Analysis of microorganisms and physicochemical properties in Zaopei during the fermentation of Chinese zhijiang-flavor liquor

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    Zhijiang-flavor liquor, one of the most famous strong aroma style of Chinese liquor, is distilled from fermented grains in Hubei province of China. In order to know the diversity, the constitution, and thedynamic change of microflora and physicochemical components in Zaopei during the fermentation of Chinese Zhijiang-flavor liquor, a normal pit in Zhijiang Distillery in autumn (used as experimental pit) was studied. The analysis and comparison of microorganisms in Zaopei during the fermentation process showed that the microbial genera changed with increasing fermentation time. Knowledge of the microbial diversity provides a basis for understanding the role and the contribution of microbes inthe liquor-production process. More than 200 colonies were isolated and characterized. The isolates were discriminated by phenotypic, conventional biochemical taxonomic methods and bioMerieux Vitek- 32. The presence of bacteria, moulds, yeasts and antinomycetes were revealed. The results showed that bacteria, yeasts, moulds and antinomycetes counts increased significantly during the first 4 days of the fermentation, and the latter three decreased sharply in the following 3 days; the total microbialpopulation decreased gradually during the 7 and 24 days; the proportion of bacillus to aerobiotic bacteria had a rise after 24 days fermentation. In this study, 5 bacillus isolates were identified with species by VITEK-32 system. The 5 bacillus isolates were Bacillus cereus group, Bacillusamyloliquefaciens, Bacillus megaterium, Bacillus sphaericus and Bacillus pumilus

    Semisolid processing characteristics of AM series Mg alloys by rheo-diecasting

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    The official published version of this Article can be found at the link below - Copyright @ 2006 ASM InternationalAn investigation has been made into the solidification behavior and microstructural evolution of AM50, AM70, and AM90 alloys during rheo-diecasting, their processibility, and the resulting mechanical properties. It was found that solidification of AM series alloys under intensive melt shearing in the unique twin-screw slurry maker during rheo-diecasting gave rise to numerous spheroidal primary magnesium (Mg) particles that were uniformly present in the microstructure. As a result, the network of the beta-Mg17Al12 phase was consistently interrupted by these spheroidal and ductile particles. Such a microstructure reduced the obstacle of deformation and the harmfulness of the beta-Mg17Al12 network on ductility, and therefore improved the ductility of rheo-diecast AM alloys. It was shown that, even with 9 wt pct Al, the elongation of rheo-diecast AM90 still achieved (9 +/- 1.2) pct. Rheodiecasting thus provides an attractive processing route for upgrading the alloy specification of AM series alloys by increasing the aluminum (Al) content while ensuring ductility. Assessment of the processibility of AM series alloys for semisolid processing showed that high Al content AM series alloys are more suitable for rheo-diecasting than low Al content alloys, because of the lower sensitivity of solid fraction to temperature, the lower liquidus temperature, and the smaller interval between the semisolid processing temperature and the complete solidification temperature.This work is supported by the EPSR

    On 2D Viscoelasticity with Small Strain

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    An exact two-dimensional rotation-strain model describing the motion of Hookean incompressible viscoelastic materials is constructed by the polar decomposition of the deformation tensor. The global existence of classical solutions is proved under the smallness assumptions only on the size of initial strain tensor. The proof of global existence utilizes the weak dissipative mechanism of motion, which is revealed by passing the partial dissipation to the whole system.Comment: Different contributions of strain and rotation of the deformation are studied for viscoelastic fluids of Oldroyd-B type in 2
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