5,422 research outputs found

    Plaquette order and deconfined quantum critical point in the spin-1 bilinear-biquadratic Heisenberg model on the honeycomb lattice

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    We have precisely determined the ground state phase diagram of the quantum spin-1 bilinear-biquadratic Heisenberg model on the honeycomb lattice using the tensor renormalization group method. We find that the ferromagnetic, ferroquadrupolar, and a large part of the antiferromagnetic phases are stable against quantum fluctuations. However, around the phase where the ground state is antiferroquadrupolar ordered in the classical limit, quantum fluctuations suppress completely all magnetic orders, leading to a plaquette order phase which breaks the lattice symmetry but preserves the spin SU(2) symmetry. On the evidence of our numerical results, the quantum phase transition between the antiferromagnetic phase and the plaquette phase is found to be either a direct second order or a very weak first order transition.Comment: 6 pages, 9 figures, published versio

    Fazna ravnoteža u sustavu NaNO3/KNO3 + glicerol + voda pri 288.15 K i 298.15 K

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    Solubility, density, and refractive index were determined for the ternary systems of NaNO3/KNO3 + glycerol + H2O at 288.15 K and 298.15 K. The solubility of the salts was calculated by the method of combining density and refractive index. In all cases the solubility of the salts decreased with the increase in glycerol content. A reverse trend for the refractive indices was observed. However, NaNO3 density tended to decrease and KNO3 density tended to increase with the addition of glycerol in the solution. Moreover, the experimental data were correlated using a four-parameter and seven-parameter empirical equation for the saturated and unsaturated solutions, respectively. Therefore, research of such kind of system has potential theoretical and practical application for the purification process and thermodynamic chemistry.U ternarnom sustav NaNO3/KNO3 + glicerol + voda određeni su topljivost, gustoća i indeks loma pri 288,15 K i 298,15 K. Topljivost je izračunata na temelju gustoće i indeksa loma. U svim se slučajevima topljivost smanjuje s povećanjem udjela glicerola. Za indeks loma uočen je suprotan trend. Dodatkom glicerola smanjuje se gustoća otopine NaNO3, a povećava gustoća otopine KNO3. Eksperimentalni podatci za zasićene i podzasićene otopine korelirani su empirijskom jednadžbom s četiri i sedam parametara. Istraživanje ovakvih sustava ima moguću primjenu u pročišćivanju i termodinamici

    SECF: Improving SPARQL Querying Performance with Proactive Fetching and Caching

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    Querying on SPARQL endpoints may be unsatisfactory due to high latency of connections to the endpoints. Caching is an important way to accelerate the query response speed. In this paper, we propose SPARQL Endpoint Caching Framework (SECF), a client-side caching framework for this purpose. In particular, we prefetch and cache the results of similar queries to recently cached query aiming to improve the overall querying performance. The similarity between queries are calculated via an improved Graph Edit Distance (GED) function. We also adapt a smoothing method to implement the cache replacement. The empirical evaluations on real world queries show that our approach has great potential to enhance the cache hit rate and accelerate the querying speed on SPARQL endpoints

    Aggregation-induced emission fluorogens as biomarkers to assess the viability of microalgae in aquatic ecosystems

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    Open Access Article. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.Microalgae can be a valuable indicator for monitoring water pollution due to their sensitivity to the changes induced by pollutants in the environment. In this study, an aggregation-induced emission fluorogen was used as a novel tool to differentiate dead and live microalgae and quantify the link between live algal concentration and fluorogen intensity. Protein in the cell protoplasm is the key component contributing to fluorescence emission in algae

    Troubleshooting Arterial-Phase MR Images of Gadoxetate Disodium-Enhanced Liver.

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    Gadoxetate disodium is a widely used magnetic resonance (MR) contrast agent for liver MR imaging, and it provides both dynamic and hepatobiliary phase images. However, acquiring optimal arterial phase images at liver MR using gadoxetate disodium is more challenging than using conventional extracellular MR contrast agent because of the small volume administered, the gadolinium content of the agent, and the common occurrence of transient severe motion. In this article, we identify the challenges in obtaining high-quality arterial-phase images of gadoxetate disodium-enhanced liver MR imaging and present strategies for optimizing arterial-phase imaging based on the thorough review of recent research in this field

    Identifying Domains and Concepts in Short Texts via Partial Taxonomy and Unlabeled Data

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    Accurate and real-time identification of domains and concepts discussed in microblogging texts is crucial for many important applications such as earthquake monitoring, influenza surveillance and disaster management. Existing techniques such as machine learning and keyword generation are application specific and require significant amount of training in order to achieve high accuracy. In this paper, we propose to use a multiple domain taxonomy (MDT) to capture general user knowledge. We formally define the problems of domain classification and concept tagging. Using the MDT, we devise domain-independent pure frequency count methods that do not require any training data nor annotations and that are not sensitive to misspellings or shortened word forms. Our extensive experimental analysis on real Twitter data shows that both methods have significantly better identification accuracy with low runtime than existing methods for large datasets

    Antihyperglycemic and Antioxidant Activity of Fructus hordei Germinatus Extract on Streptozotocin-induced Diabetic Rats

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    Purpose: To explore the antihyperglycemic and antioxidant effects of Fructus Hordei Germinatus extract (FHGE) in diabetic rats.Methods: The aqueous extract of FHG was obtained by steeping the dried Fructus Hordei Germinatus in water at 60oC three times, each for 1 h before first drying in an oven and then freeze-drying the last extract thus obtained. Antihyperglycemic effect was measured by blood glucose and plasma insulin levels. Oxidative stress was evaluated in liver and kidney by antioxidant markers, viz, lipid peroxidation (LPO), superoxide dismutase (SOD), reduced glutathione (GSH), glutathione peroxidase (GPx) and catalase (CAT), while blood serum levels of creatinine and urea were also determined in both diabetic control and treated rats.Results: Compared with diabetic rats, oral administration of FHGE at a concentration of 20, 40 and 80 mg/kg daily for 45 days showed a significant decrease in fasting blood glucose (p < 0.05) and increased insulin (p < 0.05) level,. Furthermore, it significantly reduced biochemical parameters (serum creatinine and serum urea, p < 0.05)). The treatment also resulted in significant increase in GSH, GPx (p < 0.05), SOD and CAT (p < 0.05), as well as decreased LPO (p < 0.05) level in the liver and kidney of diabetic rats.Conclusion: The results suggest that FHGE may effectively normalize the impaired antioxidant status in streptozotocin-induced diabetes in a dose-dependent manner. FHGE has a protective effect against lipid peroxidation by scavenging free radicals and is thus capable of reducing the risk of diabetic complications.Keywords: Fructus hordei Germinatus, Diabetic, Antihyperglycemic, Lipid peroxidation, Antioxidant, Fasting blood glucose, Creatinine, Ure
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