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991.
Yongqiang Qiu Mark E. Zappi Chiang-Hai Kuo Elizabeth C. Fleming 《Canadian Metallurgical Quarterly》1999,125(5):441-450
This research investigates the kinetic parameters associated with the ozonation of 2,3-, 2,4-, and 2,5-dichlorophenols (DCPs) in aqueous solutions at 25°C. The overall ozonation kinetics of each DCP was found to be first order with respect to each reactant concentration (i.e., DCP and ozone). Among the three isomers studied, the ozonation of 2,5-DCP was the fastest with the overall rate constant varying from 68,500 to 7,750,000 M?1 s?1 within a pH range of 2.1 to 5.0. The overall rate constant increased with pH because of the increase in the degree of dissociation of the DCP molecules to dichlorophenoxide ions. The electrophilic addition of ozone at the ortho and para positions of the molecular and ionic forms of the DCPs was postulated to be the likely mechanism for the degradation of the DCPs to chlorobenzenediols, monochlorophenols, chlorocyclohexadienediones, ethylacetate, heptanone, carboxylic acids, and other by-products that were detected using gas chromatograph∕mass spectrometry analysis. 相似文献
992.
Ann M. Ray James D. Barbour J. Steven McElfresh Jardel A. Moreira Ian Swift Ian M. Wright Alenka ?uni? Robert F. Mitchell Elizabeth E. Graham Ronald L. Alten Jocelyn G. Millar Lawrence M. Hanks 《Journal of chemical ecology》2012,38(9):1151-1158
Recent work suggests that closely related cerambycid species often share pheromone components, or even produce pheromone blends of identical composition. However, little is known of the pheromones of species in the subfamily Prioninae. During field bioassays in California, males of three species in the prionine genus Tragosoma were attracted to 2,3-hexanediols, common components of male-produced aggregation pheromones of beetles in the subfamily Cerambycinae. We report here that the female-produced sex pheromone of Tragosoma depsarium “sp. nov. Laplante” is (2R,3R)-2,3-hexanediol, and provide evidence from field bioassays and electroantennography that the female-produced pheromone of both Tragosoma pilosicorne Casey and T. depsarium “harrisi” LeConte may be (2S,3R)-2,3-hexanediol. Sexual dimorphism in the sculpting of the prothorax suggests that the pheromone glands are located in the prothorax of females. This is the second sex attractant pheromone structure identified from the subfamily Prioninae, and our results provide further evidence of pheromonal parsimony within the Cerambycidae, in this case extending across both subfamily and gender lines. 相似文献
993.
Mayhew-Ridgers G. Odendaal J.W. Joubert J. 《Antennas and Propagation, IEEE Transactions on》2005,53(10):3219-3228
This paper introduces a new variation on the capacitive feed probe for patch antennas on thick substrates. It consists of a small circular probe-fed capacitor patch that is situated next to the resonant patch. This configuration can bring about significant savings in terms of manufacturing cost, but also lends itself to a very efficient full-wave analysis. As such, the main focus of this paper is a spectral-domain moment-method formulation, which was specifically developed for the analysis of large, but finite, arrays of these antenna elements. Entire-domain and subdomain basis functions are combined in an efficient way to minimize the computational requirements, most notably computer memory. It is shown that, for general antenna array configurations, memory savings of more than 1000 times can be achieved when compared with typical commercial software packages where only subdomain basis functions are used. A number of numerical and experimental results are also included in order to verify the spectral-domain moment-method formulation and to illustrate various applications of the new antenna element. 相似文献
994.
Elizabeth Chirackal Varkey Krishnapillai Sreekumar 《Journal of Materials Science》2010,45(7):1912-1920
A new class of chiral polyurethanes containing amido linkages in the polymer backbone have been synthesized by reacting toluene
diisocyanate with isosorbide (IS) chiral moiety and the chromophores [N,N′-ethane-1,2-diyl bis(6-hydroxy hexanamide), N,N′-butane-1,4-diyl bis(6-hydroxy hexanamide) and N,N′-hexane-1,6-diyl bis(6-hydroxy hexanamide)]. The corresponding chromophores were obtained by the aminolysis of ε-caprolactone
by using the diamines, diaminoethane, diaminobutane and diaminohexane, respectively. All the polymers were synthesized according
to the symmetry conditions so as to obtain the non-centrosymmetric environment. A series of polyurethanes were synthesized
by varying the chiral–chromophore composition. The polyurethanes developed were characterized by optical and thermal methods. 相似文献
995.
Norcross John C.; Geller Jesse D.; Kurzawa Elizabeth K. 《Canadian Metallurgical Quarterly》2000,37(3):199
Examines responses from 349 psychologists of the American Psychological Association (APA) Division of Psychotherapy who completed a questionnaire regarding the prevalence of treating fellow psychotherapists, the type of psychotherapist-patients they treated, and the stressors and satisfactions of conducting such work. Three fourths of respondents related that they had treated mental health professionals and professionals-in-training over the past 3 years, and that this population constituted 3% to 796 of their caseloads. Nearly all of the therapist-patients were self-referred, and 85% received individual therapy. The psychotherapist-patients tended to be psychologists (37%) or social workers (29%) of diverse theoretical traditions, with the exception of biologically oriented clinicians. Satisfactions clustered around pleasures inherent in doing meaningful work, acknowledgment by peers, and the opportunity to help therapist-patients enhance their own clinical effectiveness. Predominant stressors concerned evaluation anxieties in treating colleagues and in the related belief that colleagues are more challenging and resistant to change. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
996.
Elizabeth M. Muggah Matthew B. McSweeney 《International Journal of Food Science & Technology》2017,52(3):808-816
In order to sustain the fast‐expanding beer industry, companies need to attract new female consumers. The main objective of this study was to identify the extrinsic and intrinsic attributes that drive female consumers' purchase of beer. A literature review and focus group (n = 6) were conducted, and six attributes were identified as purchase drivers of beer. These attributes included flavour, appearance (colour), packaging, brand, production methods and beer style. These attributes were used to design a choice‐based conjoint analysis survey. The survey was administered to 277 females (aged 35.09 ± 15.2) residing in Nova Scotia (Canada). The results indicated that sweetness has a positive effect on liking. Bitterness has a strong negative effect on liking of beer. Black colour, stouts and macro‐brewed beers also had negative effects on liking of beer products. The consumer clusters showed that generally all of the consumer groups liked sweet beers with low bitterness. 相似文献
997.
The paper analyzes the Energy Policy Act's goals and proposed action in Title VIII, the section dedicated to hydrogen. It then assesses whether or not the resources dedicated to this cause are sufficient to overcome the obstacles facing the commercial use of hydrogen and fuel cells. 相似文献
998.
The experimental drying behaviour of clingstone peach halves dehydrated without sulphites was investigated. Fruit treatments such as peeling and peeling followed by blanching led to greatly increased drying rates in comparison to unpeeled halves during isothermal dehydration. Superficial product temperature during dehydration was also affected by fruit treatment. Drying rates during isothermal dehydration were found to increase as linear air velocity increased from 2 to 4 m.s-1. Fruit size had a pronounced effect on drying rates, with halves obtained from the smallest fruit (54 mm.), showing the highest rates. Experimental drying studies were 相似文献
999.
Wang Ranxiao Frances; Hermer Linda; Spelke Elizabeth S. 《Canadian Metallurgical Quarterly》1999,113(3):475
Neurophysiological studies show that the firing of place and head-direction (HD) cells in rats can become anchored to features of the perceptible environment, suggesting that those features partially specify the rat's position and heading. In contrast, behavioral studies suggest that disoriented rats and human children rely exclusively on the shape of their surroundings, ignoring much of the information to which place and HD cells respond. This difference is explored in the current study by investigating young children's ability to locate objects in a square chamber after disorientation. Children 18–24 months old used a distinctive geometric cue but not a distinctively colored wall to locate the object, even after they were familiarized with the colored wall. Results suggest that the spatial representations underlying reorientation and object localization are common to humans and other mammals. Together with the neurophysiological findings, these experiments raise questions for the hypothesis that hippocampal place and HD cells serve as a general orientation device for target localization. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
1000.
This installment of Building Security In presents metrics that can help quantify the impact that process changes in one life-cycle phase have on other phases. 相似文献