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101.
Text is composed of words and phrases. In the bag‐of‐words model, phrases in text are split into words. This may discard the semantics of phrases, which, in turn, may give an inconsistent relatedness score between 2 texts. Our objective is to apply phrase relatedness in conjunction with word relatedness on the text relatedness task to improve text relatedness performance. We adopt 2 existing word relatedness measures based on Google n‐gram and Global Vectors for Word Representation, respectively, and incorporate them differently with an existing Google n‐gram–based phrase relatedness method to compute text relatedness. The combination of Google n‐gram–based word and phrase relatedness performs better than Google n‐gram–based word relatedness alone, by achieving the higher weighted mean of Pearson's r, ie, 0.639 and 0.619, respectively, on the 14 data sets from the series of Semantic Evaluation workshops SemEval‐2012, SemEval‐2013, and SemEval‐2015. Similarly, the combination of GloVe‐based word relatedness and Google n‐gram–based phrase relatedness performs better than GloVe‐based word relatedness alone, by achieving the higher weighted mean of Pearson's r, ie, 0.619 and 0.605, respectively, on the same 14 data sets. On the SemEval‐2012, SemEval‐2013, and SemEval‐2015 data sets, the text relatedness results obtained from the combination of Google n‐gram–based word and phrase relatedness ranked 24, 3, and 31 out of 89, 90, and 73 text relatedness systems, respectively. 相似文献
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103.
Evangelos I. Manolas 《The International journal of environmental studies》2013,70(6):989-992
In this study, groups of batch experiments were designed to identify the characteristics of alum sludge for arsenic (As) adsorption. Air-dried alum sludge (moisture content 13.9%) collected from a water treatment works in Xi’an, China, was subjected to artificial As-rich wastewater adsorption tests using As2O3 as a model As source. Adsorption behaviours were investigated and the results have shown that the Langmuir adsorption isotherm well fits the experimental data (R2 = 0.94957–0.99365). The maximum adsorption capacities range from 0.61 to 0.96 mg-As/g when the pH of the As solution was varied from 9.0 to 4.0. The prospects in China for the outcome of this study are discussed. This promising low-cost technique can eradicate As contamination in China. 相似文献
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Evangelos Karavas Georgios Ktistis Aristotelis Xenakis Emmanouel Georgarakis 《Drug development and industrial pharmacy》2013,39(6):473-489
In the present study, solid dispersion systems of felodipine (FEL) with polyvinylpyrrolidone (PVP) were developed, in order to enhance solid state stability and release kinetics. The prepared systems were characterized by using Differential Scanning Calorimetry, X-Ray Diffraction, and Scanning Electron Microscopy techniques, while the interactions which take place were identified by using Fourier Transformation-Infrared Spectroscopy. Due to the formation of hydrogen bonds between the carbonyl group of PVP and the amino groups of FEL, transition of FEL from crystalline to amorphous state was achieved. The dispersion of FEL was found to be in nano-scale particle sizes and dependent on the FEL/PVP ratio. This modification leads to partial miscibility of the two components, as it was verified by DSC and optimal glass dispersion of FEL into the polymer matrix since no crystalline structure was detected with XRD. The above deformation has a significant effect on the dissolution enhancement and the release kinetics of FEL, as it causes the pattern to change from linear to logarithmic. An impressive optimization of the dissolution profile is observed corresponding to a rapid release of FEL in the system containing 10% w/w of FEL, releasing 100% in approximately 20 min. The particle size of dispersed FEL into PVP matrix could be classified as the main parameter affecting dissolution optimization. The mechanism of such enhancement consists of the lower energy required for the dissolution due to the amorphous transition and the fine dispersion, which leads to an optimal contact surface of the drug substance with the dissolution media. The prepared systems are stable during storage at 40 ± 1°C and relative humidity of 75 ± 5%. Addition of sodium docusate as surfactant does not affect the release kinetics, but only the initial burst due to its effect on the surface tension and wettability of the systems. 相似文献
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George Savvidis Evangelos Karanikas Nikolaos Nikolaidis Ioannis Eleftheriadis Eforia Tsatsaroni 《Coloration Technology》2014,130(3):200-204
Four natural dyes, annatto, cutch, pomegranate fruit rind, and golden dock, were used as colorants for the preparation of water‐based ink‐jet inks for digital textile printing. The physical and rheological properties (pH, conductivity, surface tension, and viscosity) of the inks were measured over a period of 90 days for the evaluation of ink stability and suitability for ink‐jet printing. The inks were found to be suitable and were used for the digital printing of cotton fabrics. The prints were subjected to wash, light, and rub fastness tests and colour measurements. Colour consistency and fastness results, especially after fixation, are comparable with those of synthetic dyes, which paves the way for the production of environmentally friendly ink‐jet inks using natural dyes for the digital printing of cotton through the formulation of suitable printing techniques. 相似文献
108.
Production of biodegradable polyesters via enzymatic polymerization and solid state finishing 下载免费PDF全文
Maria Kanelli Aliki Douka Stamatina Vouyiouka Constantine D. Papaspyrides Evangelos Topakas Lefki‐Maria Papaspyridi Paul Christakopoulos 《应用聚合物科学杂志》2014,131(19)
The synthesis of aliphatic polyesters (PEs) derived from diols (1,4‐butanediol and 1,8‐octanediol) and diacids or their derivatives (diethyl succinate, sebacic acid, 1,12‐dodecanedioic acid, and 1,14‐tetradecanedioic acid) was achieved in order to produce poly(butylene succinate) (PE 4.4), poly(octylene sebacate) (PE 8.10), poly(octylene dodecanate) (PE 8.12), and poly(octylene tetradecanate) (PE 8.14). The herein suggested procedure involved two stages, both sustainable and in accordance with the principles of “green” polymerization. The first comprised an enzymatic prepolymerization under vacuum, in the presence of diphenylether as solvent using Candida antarctica lipase B as biocatalyst, whereas a low‐temperature postpolymerization step [solid state polymerization (SSP)] followed in order to upgrade the PEs quality. In the enzymatically synthesized prepolymers, the range of number–average molecular weight attained was from 3700 to 8000 g/mol with yields reaching even 97%. Subsequently, SSP of PE 4.4 and 8.12 took place under vacuum or flowing nitrogen and lasted 10–48 h, at temperatures close to the prepolymer melting point (Tm ? TSSP varied between 4°C and 14°C). The solid state finishing led to increase in the molecular weight depending on the prepolymer type, and it also contributed to improvement of the physical characteristics and the thermal properties of the enzymatically synthesized PEs. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40820. 相似文献
109.
Eleftherios Alissandrakis Evangelos Mantziaras Petros A. Tarantilis Pashalis C. Harizanis Moshos Polissiou 《European Food Research and Technology》2010,231(1):21-25
This paper presents a novel procedure to investigate the bioconversion of nectar components via the ‘intermediate’ honeybee
and under the effect of the conditions in the beehive. The procedure was applied with linalool, the major component in the
extract of Citrus spp. flowers, in order to investigate its bioconversion to linalool derivatives, the major volatiles of citrus honey. Bees
were fed daily with 1 L sugar syrup 1:1 (w/v) containing 1 mL of (±) linalool, while control bees were fed with the same amount
of linalool-free syrup. The artificial honey was analysed by means of ultrasound-assisted extraction followed by GC–MS analysis.
The results show that the formation of both furan and pyran linalool oxides as well as terpendiol I is favoured, probably
catalysed by the enzymes secreted by the bee. On the contrary, important linalool derivatives of citrus honey such as lilac
aldehydes, cis- and trans-dehydroxy linalool oxides (E)-2,6-dimethyl-6-hydroxy-2,7-octadienal and (Z)-8-hydroxylinalool were absent in the artificial honey, suggesting the requirement of a plant-derived enzyme for their bioconversion.
The same stands for (E)-8-hydroxylinalool, major volatile of citrus honey, although small amounts were present in the artificial honey. From these
results, it can be concluded that feeding honeybees with linalool-enriched sugar syrup is not an effective way to produce
artificial citrus honey similar to the natural one. 相似文献
110.
Papageorgiou SK Katsaros FK Kouvelos EP Nolan JW Le Deit H Kanellopoulos NK 《Journal of hazardous materials》2006,137(3):1765-1772
Alginate with a high M/G ratio, extracted from Laminaria digitata, was evaluated for Cu(2+), Cd(2+) and Pb(2+) sorption in acidic solutions, in the form of calcium cross-linked beads. The high M/G ratio of alginate extracted from this algal species is most likely the determining factor for the increased adsorption capacity of the investigated metals, indicating that the mannuronic acid is responsible for the ion exchange mechanism. The data obtained from the batch experiments have been interpreted with Langmuir, Freundlich and Sips models. The Sips equation provided the best fit with the experimental results, indicating sorption sites heterogeneity for the material. The pH was found to have a significant effect on the process, with sorption capacity reaching a maximum at pH 4.5, indicating a competition mechanism between H(+) and metal ions. Kinetic experiments were performed at the optimum pH. For the interpretation of the kinetic experiments the Linear Adsorption Model was employed and diffusion coefficients were determined. The model fits the experimental data at higher concentrations, where the adsorbed quantity remains almost constant. Finally, a simplified expression of the batch kinetic adsorption model was employed. The model, predicts adequately, not only the diffusivity values, but also the concentration profiles inside the spherical particles. 相似文献