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101.
In the present study, the effects of charge‐transfer complex formation and intramolecular fragmentation (side‐chain lactonization) in radical copolymerization of tert‐butyl vinyl ether (t‐BVE) with anhydrides of maleic (MA) and citraconic (CA) acids and the structure–thermal behavior relationships of the resulting copolymers were examined using the 1H‐NMR, FTIR, DSC, and TGA analysis methods. It was shown that copolymerization under the chosen conditions proceeded through intramolecular fragmentation with the formation of γ‐lactone units. Side‐chain fragmentation of t‐BVE–MA and t‐BVE–CA copolymers also was confirmed by TGA and DSC analysis. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2455–2463, 2006 2006 相似文献
102.
Thermal characterization of maleic anhydride‐styrene‐allyl propionate (MA‐St‐AP) terpolymer and its ester derivatives named as n‐alkyl maleate and shown as nPr MA‐St‐AP, nBu MA‐St‐AP, nPn MA‐St‐AP, and nBz MA‐St‐AP was carried out. The thermal characterization was performed using thermal analysis techniques such as TGA, DTA, DSC, and TMA. Different results were observed between the original terpolymer and its ester derivatives. Thermal stabilities of the terpolymer and its ester derivatives were compared by using various measurements plotted as TGA, DTA, DSC, and TMA curves. The increase in the alcohols' carbon numbers added to the original terpolymer results in ester derivatives with different thermal stability behavior. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 600–604, 2007 相似文献
103.
Kwang‐Pill Lee Anantha Iyengar Gopalan See‐Hee Lee Ali Md Showkat Young Chang Nho 《应用聚合物科学杂志》2006,102(4):3912-3918
Conducting polydiphenylamine was used to encapsulate silica nanoparticles through the oxidative polymerization of diphenylamine in the presence of ultrasonic irradiation. The polymerization was performed in the presence of sodium lauryl sulfate as a surfactant. Experiments performed in the absence of ultrasound clearly demonstrated that the application of ultrasonication played multiple roles in the preparation of a composite of polydiphenylamine with silica nanoparticles. Ultrasonication dispersed the silica nanoparticles, converted sodium lauryl sulfate to lauryl alcohol, and augmented the dispersion of the silica‐nanoparticle/polydiphenylamine composite in an organic medium. Silica‐nanoparticle/polydiphenylamine composites were also prepared in the absence of ultrasound and/or sodium lauryl sulfate. The silica‐nanoparticle/polydiphenylamine composites were characterized with Fourier trans form infrared spectroscopy, ultraviolet–visible/near‐infrared spectroscopy, and thermogravimetric analysis. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3912–3918, 2006 相似文献
104.
Electropolymerization of pyrrole on lead substrate electrode was studied. Due to electrochemical activity of Pb in acidic media, this process is only possible at basic pHs. For this purpose, electropolymerization process was performed in an aqueous solution of Na2SO4 with pH 12. Potentiodynamic cycling shows the Pb oxidation at the first cycles. In subsequent cycles, polypyrrole film grows on the oxidized lead substrate. Of course, as the passive film is highly porous, a composite of polypyrrole/PbSO4 is formed in the first layers. However, subsequent cycling leads to the formation of pure polypyrrole film. According to this structure and strong connection of the polymer film to the substrate surface via this composite layer, the polypyrrole film deposited on the lead surface has enhanced mechanical stability. AFM measurements showed peculiar smoothness of both composite and lateral polypyrrole films. This synthesis approach is of particular interest for the preparation of highly stable polymer films and fabrication of supercapacitors with a polymer/PbSO4 conductive structure. 相似文献
105.
探讨了尿素嵌入法制备纤维素氨基甲酸酯(CC)的生产工艺。指出:选用聚合度为450~625、α-纤维素含量大于90/的纤维素浆粕,用14/~16/的氢氧化钠溶液,于40~50℃条件下活化处理30~40min后,与尿素以1∶2~3的比例混合,在137℃的二甲苯体系中反应2~3h,便可得到含氮量为2.4/~3.5/的纤维素氨基甲酸酯产物。该产物在氢氧化钠溶液中可形成良好的稳定溶液,过滤性好,可直接用于纺丝。 相似文献
106.
Sutharshan Rajasegarar Alexander Gluhak Muhammad Ali Imran Michele Nati Masud Moshtaghi Christopher Leckie Marimuthu Palaniswami 《Pattern recognition》2014
Anomaly detection in resource constrained wireless networks is an important challenge for tasks such as intrusion detection, quality assurance and event monitoring applications. The challenge is to detect these interesting events or anomalies in a timely manner, while minimising energy consumption in the network. We propose a distributed anomaly detection architecture, which uses multiple hyperellipsoidal clusters to model the data at each sensor node, and identify global and local anomalies in the network. In particular, a novel anomaly scoring method is proposed to provide a score for each hyperellipsoidal model, based on how remote the ellipsoid is relative to their neighbours. We demonstrate using several synthetic and real datasets that our proposed scheme achieves a higher detection performance with a significant reduction in communication overhead in the network compared to centralised and existing schemes. 相似文献
107.
M. A. Ali M. A. Gafur M. S. Rahman G. M. Ahmed 《Journal of the American Oil Chemists' Society》1985,62(3):520-523
The kernels of 10 different mango varieties were extracted. The physico-chemical characteristics and lipid class composition
of fats were studied. The fat content of mango kernels grown under the soil and climatic conditions of Bangladesh varied from
7.1% to 10%, depending on the variety. The total lipid extracts were fractionated into lipid classes by a combination of column
and thin layer chromatography (TLC). The hydrocarbon and sterol esters varied from 0.3% to 0.7%, triglycerides from 55.6%
to 91.5%, partial glycerides from 2.3% to 4% and free sterol from 0.3% to 0.6%. Free fatty acids amounted to 3.0–37% as oleic;
glycolipids were 0.6–1.2% and phospholipids 0.11–0.8%. The fatty acid composition of triglyceride (TG) fractions was analyzed
by gas liquid chromatography (GLC). Palmitic acid varied from 7.9 molar % to 10.0 molar %, stearic from 38.2% to 40.2%, oleic
from 41.1% to 43.8%, linoleic from 6.0% to 7.6%, linolenic from 0.6% to 1.0% and arachidic acid from 1.7% to 2.6%. TLC revealed
the presence of lyso-phosphatidylcholine, phosphatidylcholine, phosphatidylinositol, phosphatidylethanolamine and phosphatidic
acid in the phospholipid fraction. 相似文献
108.
Thermoplastic interpenetrating polymer networks (IPN) are mixtures of two physically crosslinked polymers. Thermoplastic IPNs were prepared by blending an SBS triblock elastomer with a 1,2-polybutadiene that was ionically-terminated at both ends. The morphologies of these IPNs were studied using differential scanning calorimetry and dynamic mechanical thermal analysis. It was concluded that the ionomer was incompatible with the SBS elastomer, since the Tgs of both the 1,2-polybutadiene from the ionomer and the essentially 1,4-polybutadiene from the SBS component were observable at temperatures that were close to those of the individual components. The addition of the polybutadiene material had, however, an influence on the relaxation processes of the polystyrene blocks. The polystyrene glass transition in the pure SBS copolymer is broadened by the interfacial region between polystyrene and polybutadiene. The low temperature shoulder was much more pronounced when the ion-terminated polybutadiene was present, indicating it has a preference to be located in these interfacial regions. © 1994 John Wiley & Sons, Inc. 相似文献
109.
Yuichiro?Furukawa Kazuyuki?InubushiEmail author Mochamad?Ali A.?M.?Itang Haruo?Tsuruta 《Nutrient Cycling in Agroecosystems》2005,71(1):81-91
Monthly measurements of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) fluxes in peat soils were carried out and compared with groundwater level over a year at four sites (drained forest, upland cassava,upland and lowland paddy fields) located in Jambi province, Indonesia. Fluxes from swamp forest soils were also measured once per year as the native state of this investigated area. Land-use change from drained forest to lowland paddy field significantly decreased the CO2 (from 266 to 30 mg C m–2 h–1) and N2O fluxes (from 25.4 to 3.8 g N m–2 h–1), but increased the CH4 flux (from 0.1 to 4.2 mg C m–2 h–1) in the soils. Change from drained forest to cassava field significantly increased N2O flux (from 25.4 to 62.2 g N m–2 h–1), but had no significant influence on CO2 (from 266 to 200 mg C m–2 h–1) and CH4 fluxes (from 0.1 to 0.3 mg C m–2 h–1) in the soils. Averaged CO2 fluxes in the swamp forests (94 mg C m–2 h–1) were estimated to be one-third of that in the drained forest. Groundwater levels of drained forest and upland crop fields had been lowered by drainage ditches while swamp forest and lowland paddy field were flooded, although groundwater levels were also affected by precipitation. Groundwater levels were negatively related to CO2 flux but positively related to CH4 flux at all investigation sites. The peak of the N2O flux was observed at –20 cm of groundwater level. Lowering the groundwater level by 10 cm from the soil surface resulted in a 50 increase in CO2 emission (from 109.1 to 162.4 mg C m–2 h–1) and a 25% decrease in CH4 emission (from 0.440 to 0.325 mg C m–2 h–1) in this study. These results suggest that lowering of groundwater level by the drainage ditches in the peat lands contributes to global warming and devastation of fields. Swamp forest was probably the best land-use management in peat lands to suppress the carbon loss and greenhouse gas emission. Lowland paddy field was a better agricultural system in the peat lands in terms of C sequestration and greenhouse gas emission. Carbon loss from lowland paddy field was one-eighth of that of the other upland crop systems, although the Global Warming Potential was almost the same level as that of the other upland crop systems because of CH4 emission through rice plants. 相似文献
110.
Mohamed Zerrougui Mohamed Darouach Latifa Boutat-Baddas Harouna Souley Ali 《International Journal of Control, Automation and Systems》2014,12(3):590-598
In this paper, we consider the H ∞ filters design for singular bilinear systems. The approach is based on the parameterized solution of a set of constrained Sylvester equations. The exponential convergence and l 2 gain attenuation problems are solved by using the bounded real lemma, which leads to linear matrix inequalities (LMI) formulation. Finally, a detailed design procedure is given for the estimation of the states of a flexible joint robot, which demonstrates the effectiveness of the proposed method. 相似文献