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排序方式: 共有160条查询结果,搜索用时 359 毫秒
101.
M.R. Bayati F. Golestani-Fard A.Z. Moshfegh Roya Molaei 《Materials Research Bulletin》2011,46(10):1642-1647
Micro arc oxidation technique, as a facile and efficient process, was employed to grow sulfur doped titania porous layers. This research sheds light on the photocatalytic performance of the micro arc oxidized S-TiO2 nano-porous layers fabricated under pulse current. Morphological and topographical studies, performed by SEM and AFM techniques, revealed that increasing the frequency and/or decreasing the duty cycle resulted in formation of finer pores and smoother surfaces. XRD and XPS results showed that the layers consisted of anatase and rutile phases whose fraction was observed to change depending on the synthesis conditions. The highest anatase relative content was obtained at the frequency of 500 Hz and the duty cycle of 5%. Furthermore, photocatalytic activity of the layers was examined by measuring the decomposition rate of methylene blue under both ultraviolet and visible photo irradiations. Maximum photodegradation reaction rate constants over the pulse-grown S-TiO2 layers were respectively measured as 0.0202 and 0.0110 min−1 for ultraviolet and visible irradiations. 相似文献
102.
103.
Aliakbar Mohammadi Hamid Khaloozadeh Roya Amjadifard 《International Journal of Control, Automation and Systems》2013,11(3):489-495
In this paper, we propose a novel index for the prediction of the Hopf bifurcation (HB) in power systems. The proposed index has strictly less processing load and less computation time in comparison to former HB indices. It also uses modern control properties of the power system such as system matrix and critical eigenvalue. Therefore, stochastic subspace system identification (SSSI) is used as a tool for estimation and prediction of the proposed HB index. Combining beneficial properties of SSSI methods and the processing advantages of the proposed index, we project a new algorithm for power system monitoring. The algorithm is easy and straight-forward. We conduct several test conditions for the proposed materials using 2-area 4-machine system, New England 10-Machine and IEEE 50-machine system. Simulation outcome expresses good performance of proposed index in comparison to former HB indices. The proposed index has fairly linear behavior, without discontinuities with respect to increases of system load. It also has less computation load. 相似文献
104.
Gao S Ng NL Keywood M Varutbangkul V Bahreini R Nenes A He J Yoo KY Beauchamp JL Hodyss RP Flagan RC Seinfeld JH 《Environmental science & technology》2004,38(24):6582-6589
A series of controlled laboratory experiments are carried out in dual Teflon chambers to examine the presence of oligomers in secondary organic aerosols (SOA) from hydrocarbon ozonolysis as well as to explore the effect of particle phase acidity on SOA formation. In all seven hydrocarbon systems studied (i.e., alpha-pinene, cyclohexene, 1-methyl cyclopentene, cycloheptene, 1-methyl cyclohexene, cyclooctene, and terpinolene), oligomers with MW from 250 to 1600 are present in the SOA formed, both in the absence and presence of seed particles and regardless of the seed particle acidity. These oligomers are comparable to, and in some cases, exceed the low molecular weight species (MW < 250) in ion intensities in the ion trap mass spectra, suggesting they may comprise a substantial fraction of the total aerosol mass. It is possible that oligomers are widely present in atmospheric organic aerosols, formed through acid- or base-catalyzed heterogeneous reactions. In addition, as the seed particle acidity increases, larger oligomers are formed more abundantly in the SOA; consequently, the overall SOA yield also increases. This explicit effect of particle phase acidity on the composition and yield of SOA may have important climatic consequences and need to be considered in relevant models. 相似文献
105.
Comparison of two inference methods for P-type fuzzy logic control through experimental investigation using a hydraulic manipulator 总被引:2,自引:0,他引:2
This paper presents a comparison of the two important inference schemes: “individual-rule-based inference” and “compositional rule of inference” as applied to fuzzy logic control, through experimental investigation. The techniques are implemented on a hydraulic manipulator of an industrial machine with P-type fuzzy control. The fuzzy logic controller is designed for automatic positioning of the cutter blade of an automated fish-cutting machine. The features of the machine, which uses hydraulic servo control for cutter positioning, are outlined. The performance of the machine under the two inference schemes is examined and contrasted. Some practical implementations of the results are indicated. 相似文献
106.
Mohammad Hossein Rouhani Roya Kelishadi Mahin Hashemipour Ahmad Esmaillzadeh Leila Azadbakht 《Lipids》2013,48(12):1197-1205
Some studies focused on the effect of the dietary glycemic index on lipoproteins and apolipoproteins in adults; however, little evidence exists among adolescents regarding the effect of a low glycemic index (LGI) diet on apolipoproteins and lipoprotein (a) (Lpa). This study was conducted to evaluate the effect of an LGI diet on the lipid profile, apolipoproteins and Lpa among overweight and obese adolescent girls. For this parallel designed randomized clinical trial, 50 healthy overweight/obese girls at pubertal ages were randomly allocated to an LGI or a healthy nutritional recommendations (HNR) based diet. Equal macronutrient distributed diets were prescribed to both groups. Biochemical measurements included lipid profile, apolipoprotein A, apolipoprotein B and Lpa were conducted before and after 10 weeks of intervention. Forty one adolescent girls completed the study. The dietary glycemic index in the LGI group was 42.67 ± 0.067. There were no differences in the mean of blood lipid indices baseline and after intervention between two groups. There were no significant differences between the two groups regarding lipid profiles, apolipoproteins and Lpa. There were no significant differences in lipid profiles, apolipoproteins and Lpa between the LGI diet and the HNR-based diet and the impact of these two diets on lipid profile was equal in this trial. Trial registry code: IRCT201109272839N4. 相似文献
107.
Ganesh Kumar Agrawal Abhijit Sarkar Pier Giorgio Righetti Romina Pedreschi Sebastien Carpentier Tai Wang Bronwyn J. Barkla Ajay Kohli Bongani Kaiser Ndimba Natalia V. Bykova Christof Rampitsch Lello Zolla Mohamed Suhail Rafudeen Rainer Cramer Laurence Veronique Bindschedler Nikolaos Tsakirpaloglou Roya Janeen Ndimba Jill M. Farrant Jenny Renaut Dominique Job Shoshi Kikuchi Randeep Rakwal 《Mass spectrometry reviews》2013,32(5):335-365
108.
Roya Khalil Andrew George Chryss Margaret Jollands Satinath Bhattacharya 《Journal of Materials Science》2007,42(24):10219-10227
This paper focuses on the application of silica rich, rice hull ash (RHA) from the rice industry as filler in polypropylene
(PP). The dynamic rheological behaviour and the crystallinity of its composites with semi-amorphous polypropylene were used
as performance indicators. The effect of coupling agents on RHA/PP compatibility was also investigated. Addition of RHA increased
storage modulus (G′), and the onset (T
co) and peak (T
c) crystallinity temperatures, and decreased the degree of crystallinity of the system. Two coupling agents, maleated polypropylene
(MAPP) and an amino functional silane, were used to improve the interfacial adhesion of RHA and PP. Addition of MAPP increased
G′, T
c and T
co and the crystalline phase of the system. Addition of silane had mixed effects. It increased the rheological properties at
higher concentrations, it increased T
c and T
co at all the concentrations and increased crystallinity at lower concentrations and decreased it at higher concentrations.
Results from a thermogravimetric analyser were useful in revealing the mechanism by which silane bond to RHA and its effect
on the rheology and crystallisation behaviour of the composites. 相似文献
109.
A biomimetic route for synthesis of a conducting molecular complex between polyalkoxyanilines and a polyelectrolyte, poly (sodium 4‐styrenesulfonate) (SPS) is presented. Horseradish peroxidase (HRP) was used to catalyze the polymerization of alkoxyanilines. A few of water‐soluble ring‐substituted polyalkoxyanilines have been enzymatically synthesized with variation of groups, such as ortho‐methoxy, meta‐methoxy, ortho‐ethoxy, and meta‐ethoxy to form polyalkoxyanilines/SPS complexes. The presence of alkoxy substituents affects the polymerization reactions. These enzymatic oxidation reactions occur in a different potential range to that observed for the chemical polymerization. Similar electrochemical and optical properties were obtained for every pair of ortho‐ and meta‐alkoxy substituted polyanilines. For comparing, polyalkoxyanilines were also prepared by chemical polymerization in the presence of SPS. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 103: 3724–3729, 2007 相似文献
110.
Our study investigated the impact of ICT expansion on economic freedom in the Middle East (Bahrain, Iran, Jordan, Kuwait, Lebanon, Oman, Qatar, Saudi Arabia, Syria, United Arab Emirates, and Yemen). Our empirical analysis used archival data from 1995 to 2005; it showed that ICT expansion in the Middle East has been effective both in bridging the digital divide and also in promoting economic freedom in a region that was vulnerable to political, social, and global conflict. However, differences between countries, such as the educational attainment of their citizens and institutional resistance to technology acceptance, both enhanced and restricted the relationship between ICT and economic freedom. 相似文献