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1.
Summary By reacting esterification of phenolphtalein with methacrylate chloride, phenolphtalein dimethacrylate was obtained. Based on the results of elemental analysis, FTIR, 1H-NMR and 13C-NMR spectra, the structure of the product was proposed. The dimethacrylate was used as new crosslinker to crosslink poly(methyl methacrylate) (PMMA). The influence of the amount dimethacrylate on the crosslink density and some properties of the crosslinked polymers networks such as swelling, mechanical properties (tensile strength and elongation at break) and thermal stability were examined. 相似文献
2.
Oskar Maier Halina Kwasnicka Michal Stanek 《Journal of Intelligent Information Systems》2012,39(3):651-685
Developing a satisfactory and effective method for auto-annotating images that works under general conditions is a challenging task. The advantages of such a system would be manifold: it can be used to annotate existing, large databases of images, rendering them accessible to text search engines; or it can be used as core for image retrieval based on a query image’s visual content. Manual annotation of images is a difficult, tedious and time consuming task. Furthermore, manual annotations tend to show great inter-person variance: considering an image, the opinions about what elements are significant and deserve an annotation vary strongly. The latter poses a problem for the evaluation of an automatic method, as an annotation’s correctness is greatly subjective. In this paper we present an automatic method for annotating images, which addresses one of the existing methods’ major limitation, namely a fixed annotation length. The proposed method, PATSI, automatically chooses the resulting annotation’s length for each query image. It is held as simple as possible and a build-in parameter optimization procedure renders PATSI de-facto parameter free. Finally, PATSI is evaluated on standard datasets, outperforming various state-of-the-art methods. 相似文献
3.
Krzysztof Buksa Anna NowotnaRafa? Ziobro Halina Gambu?Stanis?aw Kowalski 《Food Hydrocolloids》2012,27(1):72-79
The main constituents of rye flour extracts are proteins and pentosans. After cross-linking under the action of oxidizing agents those components are able to bind much more water than in their native (prior to modifications) state. As a consequence rheological properties of extract are changed.It was observed that kinematic viscosity of water extract of rye flour decreases rapidly with time. The reason for this behavior could be high enzymatic activity of flour extract.It was also found that the addition of hydrogen peroxide in the absence of additional peroxidase (which is naturally present in 1:9 or 1:1 water extracts of flour) causes the greatest increase in viscosity, due to the cross-linking of soluble polymers. Moreover after the addition of H2O2 to water extracts strong gels were obtained, which were characterized by tan δ = 0.5 (tan δ < 1). Moreover G′ was independent of frequency, which also suggests cross-linking of the pentosans.The addition of ascorbic acid, which is known to act preferably on gluten proteins, to 1:9 or 1:1 flour extracts had only a little effect on viscosity. In this case the values of tan δ = 0.9 were close to 1, which is typical for a weak gel.The application of inactivated rye flour extract, containing mainly proteins and pentosans, proved stronger effect of H2O2 in comparison to ascorbic acid on polymer cross-linking, but only after the addition of peroxidase. The gel obtained with H2O2 and peroxidase was also characterized by low tan δ = 0.4.The results indicate, that pentosans are the main subject of cross-linking reactions in rye flour water extracts. 相似文献
4.
5.
The effect on Oenothera paradoxa oil on blood serum and liver lipids metabolism in rats fed a semisynthetic high-fat cholesterol enriched diets was investigated. The source of fats was sunflower oil or lard in 15% quantities and the source of protein was soybean protein isolate in 27% quantity. The diets were enriched with 0.5% cholesterol. This dietary experiment was carried on for 8 weeks. For the first 4 weeks rats were fed standard diet and for the next 4 weeks Oe. paradoxa oil (300 mg/day/rat) was additionally given by stomach-tube. At the end of experiment the contents of total cholesterol, HDL-cholesterol, triglycerides and free fatty acids in blood serum as well as cholesterol and triglycerides level in liver were determined. It was found, that the addition of cholesterol to the diet decreased the hypocholesterolemic and hypotriglyceridemic effects of Oe. paradoxa oil both in blood serum and liver. It have not had any significant effect on the free fatty acid concentration in blood serum decrease by Oe. paradoxa oil intake. 相似文献
6.
Atomic force microscopy (AFM) has been used to study the effect of various photoinitiators doped into poly(methyl methacrylate)
(PMMA) on the mechanical properties of PMMA films at the nanometer scale. Pure and modified PMMA films (containing four different
photoinitiators) were exposed to a mercury vapor lamp in air atmosphere. Force–distance curves for hardness, Young modulus,
and adhesion forces were obtained using different AFM modes (tapping or contact-mode) and different tips (diamond or silicon
nitride). The results revealed that the added photoinitiators slightly changed the nanomechanical properties of PMMA as a
result of alterations in the photochemical reactions and physical processes occurring in the studied systems. tert-Butyl peroxybenzoate had the most efficient effect on the measured parameters in UV-irradiated PMMA, whereas benzoyl peroxide
was less active. The mechanism of the observed processes is discussed. 相似文献
7.
A new strategy for specifically targeting cysteine-containing peptides in a tryptic digest is described. The method is based on quantitatively derivatizing cysteine residues with a quaternary amine tag (QAT). Tags were introduced into proteins following reduction of disulfide bonds through derivatization of cysteine residues with (3-acrylamidopropyl)trimethylammonium chloride. After trypsin digestion, derivatized cysteine-containing peptides were enriched by strong cation exchange chromatography. The method was validated using model peptides and a protein. The QAT strategy has several advantages over other methods for the selection of cysteine-containing peptides. One is that it increases the ionization efficiency of cysteine-containing peptides. The other is that chromatographic selection is achieved with simple, robust cation exchange chromatography columns. As a result, this new strategy provides a simple way to facilitate enrichment of cysteine-containing peptides, thereby reducing sample complexity in bottom-up proteomics. 相似文献
8.
Dorota Koodyska Halina Hubicka 《Chemical engineering journal (Lausanne, Switzerland : 1996)》2009,150(2-3):308-315
The polyacrylate anion exchangers are widely used in purification of heavy metal ions from wastewaters and different accompanying complexing agents. Such effluents containing the chelators (EDTA, NTA, HEDTA, DTPA, and IDA) are discharged from relevant industries such as printed circuits boards, plating on plastics, metal finishing and others. The sorption was studied as a function of phase contact time and pH by the batch technique. It was found that the removal of heavy metal ions in the presence of EDTA, NTA and IDA strictly depends on the phase contact time and pH values. Various kinetic models such as the pseudo first-order and the pseudo second-order as well as the intraparticle one were also tested to estimate the sorption rate. The equilibrium capacities of the studied anion exchangers for Cu(II), Zn(II), Co(II), Ni(II), Pb(II) and Cd(II) in the presence of EDTA were the highest for Pb(II) and Cd(II). The order of sorption for Amberlite IRA 458, Amberlite IRA 958 as well as Amberlite IRA 67 can be as follows: Pb(II) > Cd(II) > Zn(II) > Cu(II) > Ni(II) > Co(II). The stability of forming complexes was also compared. The estimation of the capacities of anion exchangers under investigation by the continuous column studies was also carried out. 相似文献
9.
Halina Czternastek 《Vacuum》2008,82(10):994-997
Al-doped ZnO films were prepared by the dc magnetron sputtering technique on Suprasil-1 substrates at a temperature of 470 K. Plasma-emission monitoring was used to stabilize oxygen flow to the deposition chamber. The effect of substrate position during deposition on the structural, electrical and optical properties of the films was investigated. It was found that preparation of low-resistance films with high optical transmission over the visible region is possible under condition of low plasma effects on the growing film. 相似文献
10.