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排序方式: 共有246条查询结果,搜索用时 0 毫秒
241.
Wilfrida Nyanduko Nyairo Yasin Ramazan Eker Chrispin Kowenje Ilker Akin Haluk Bingol Ali Tor 《分离科学与技术》2018,53(10):1498-1510
Polypyrrole coated oxidized multiwalled carbon nanotubes (oMWCNT/Ppy) were applied to determine the adsorption characteristics of Pb(II) and Cu(II) from their aqueous solutions. Structural and morphological characterization studies using scanning electron microscopy, thermogravimetric analysis, Fourier transform infrared and Raman spectroscopy showed successful preparation of the oMWCNT/Ppy composite. The influence of pH, contact time, and initial metal ion concentration on the adsorption of Pb(II) and Cu(II) was studied. The adsorption processes fitted well with Langmuir isotherm and pseudo-second-order kinetic models. The maximum adsorption capacities for Pb(II) and Cu(II) were determined as 26.32 and 24.39 mg/g, respectively. Desorption studies indicated that the oMWCNT/Ppy composite could be reused for five cycles with minimum loss of its initial adsorption capacity. 相似文献
242.
Bulent E. Yoldas 《International Journal of Applied Glass Science》2014,5(3):248-254
As it is well known, the structures of silica and soda-lime-silica glasses are subjected to alkali ion diffusion. This diffusion can lead to staining of the glass surface, thus detrimentally affecting its optical functions. In this work, an effective alkali diffusion barrier layer is created by boron diffusion into the top 10 to 50-nm thick layer of glass surface. In this layer, alkali mobility is electrochemically arrested by a coordination change of boron. As a result, the glass surface stays pristinely clear, even under sustained exposure to hot and humid conditions. Structural studies indicate that when three-coordinated boron diffuses into a pre-existing glass network, it converts nonbridging oxygens, associated with alkali ions, into bridging oxygens by changing its coordination from 3 to 4. This forces alkali ions to change their bond association from nonbridging oxygens to the charge sphere of boron due to the required charge neutrality. This new bond arrangement immobilizes the alkali ions at these sites. As a result of the alkali ion immobilization, and the reduction in nonbridging oxygens in the network, the glass surface becomes resistant to nucleophillic attack, as well as resistant to stain formation, and crystallization. 相似文献
243.
Carstensen Laura L.; Turan Bulent; Scheibe Susanne; Ram Nilam; Ersner-Hershfield Hal; Samanez-Larkin Gregory R.; Brooks Kathryn P.; Nesselroade John R. 《Canadian Metallurgical Quarterly》2011,26(1):21
Recent evidence suggests that emotional well-being improves from early adulthood to old age. This study used experience-sampling to examine the developmental course of emotional experience in a representative sample of adults spanning early to very late adulthood. Participants (N = 184, Wave 1; N = 191, Wave 2; N = 178, Wave 3) reported their emotional states at five randomly selected times each day for a one week period. Using a measurement burst design, the one-week sampling procedure was repeated five and then ten years later. Cross-sectional and growth curve analyses indicate that aging is associated with more positive overall emotional well-being, with greater emotional stability and with more complexity (as evidenced by greater co-occurrence of positive and negative emotions). These findings remained robust after accounting for other variables that may be related to emotional experience (personality, verbal fluency, physical health, and demographic variables). Finally, emotional experience predicted mortality; controlling for age, sex, and ethnicity, individuals who experienced relatively more positive than negative emotions in everyday life were more likely to have survived over a 13 year period. Findings are discussed in the theoretical context of socioemotional selectivity theory. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
244.
Carcass measurements and meat quality characteristics of dairy suckling kids compared to an indigenous genotype 总被引:2,自引:0,他引:2
Effects of genotype on carcass measurements and meat quality were investigated by using 24 suckling kids from Turkish Saanen, Gokceada and Maltese breeds. Carcass quality characteristics of indigenous kids (Gokceada) were lower than those of dairy type (Turkish Saanen and Maltese) kids. Breed effect on ultimate meat pH, cooking loss, drip loss and Warner Bratzler shear force values were not significant. Meat samples from Turkish Saanen kids had higher redness (at 0, 1 and 24 h) and yellowness (at 24 h) values than Gokceada kids (P < 0.05). Breed had no significant effect on sensory characteristics except flavour intensity. Flavour intensity scores given to meat samples of Maltese kids were higher than those of Turkish Saanen and Gokceada kids (P < 0.01). In conclusion, dairy type breeds should be considered for meat production as well, with meat from Maltese kids potentially offering better colour and flavour intensity than that of Turkish Saanen kids. 相似文献
245.
Effect of fruit canopy positions on the properties of apricot (Prunus armeniaca L.) varieties 下载免费PDF全文
Ihsan Karabulut Tugca Bilenler Kubra Sislioglu Incilay Gokbulut Ferda Seyhan Ibrahim Sani Ozdemir Bulent Ozturk 《Journal of Food Biochemistry》2018,42(1)
Effect of fruit position in the tree on properties of two commercially important apricot varieties (Hac?halilo?lu and Kabaa??) was investigated. Principal component analysis separated apricots based on their variety and canopy position. Hac?halilo?lu variety was distinguished from Kabaa?? variety by its higher pH, weight, dry matter (DM), soluble solid, citric acid, and catechin content. Major features which contribute to variation of the canopy position were β‐carotene, malic acid, catechin, ascorbic acid, soluble solid content, DM, malic acid, and neochlorogenic acid. Fruits located on the top of the tree were richer in phenolic compounds and exhibited higher degree of antioxidant activity measured by 2.2′‐azinobis[3‐ethylbenzthiazoline‐6‐sulphonic acid] (ABTS) method than those located on the bottom of the tree. Except for chlorogenic and neochlorogenic acids, all other forms of phenolic compounds were higher in concentration in the fruits located on the top of the canopy especially for the Hac?halilo?lu variety.
Practical applications
The results of this study may be of interest for apricot breeders as it provides important information about cultivar specific canopy effect on fruit quality. Furthermore, the results can be used by apricot producers for canopy management and pruning strategies to create of homogenous microclimate in the fruit canopy which would limit quality variation. 相似文献246.
In the study, the production of biohydrogen by extracted fermentation from sugar beet was evaluated. Effects of initial amount of sugar beet, biomass and particle size of sugar beet on biohydrogen formation were investigated. The hydrogen (H2) gas was predicted to be 78.6 mL at initial dry weight of sugar beet 24.6 g L?1 and H2 yield was calculated as 81.9 mLH2 g?1TOC while biomass concentration (1 g L?1) and particle size (0.3 cm) were constant. The peak H2 gas volume was predicted to be 139.9 mL at the low particle size of 0.1 cm. Hydrogen gas production potential was predicted as 143.6 mL h?1. The peak value of 197.9 mLH2 g?1TOC was obtained with particle size of 0.1 cm when dry weight of sugar beet and initial amount of biomass was kept constant at 24.6 g L?1 and 1 g L?1, respectively. 相似文献