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51.
The rubber industry is nowadays facing the general increase of raw materials as the customers are confronted with rising prices for energy. Therefore there is a need for higher durability of elastomer applications. Short fiber reinforced elastomers can contribute to the improvement of dynamic and wear properties. To determine structure–property relationships in short fiber reinforced elastomer compounds it is of crucial interest to know the contributions of fiber aspect ratio, volume content, orientation and fiber–elastomer interaction. Therefore the influence of different processing conditions and fiber contents on the resulting morphology and macroscopic properties was investigated in this article by the help of fluorescence and confocal laser microscopy using a transparent ethylene‐propylene‐diene rubber (EPDM) matrix. It was found that the processing induced fiber breakage was the key factor in determining the composite morphology and subsequent physical properties. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1682–1690, 2013 相似文献
52.
53.
Comments on the article of J. S. Phinney (see record 83-36985) about what it means to talk about American ethnic groups. It is suggested that Phinney's advocacy of the combining of the terms ethnicity and race into a single construct in psychology presumes that ethnicity can encompass all aspects of race and culture. But, it is argued here, in psychology and American society at large, ethnicity seemingly has no real meaning apart from its status as a proxy for racial classification or immigrant status, while race has a clear meaning. Drawing on a cursory review of psychology abstracts, it is suggested that it is ill-advised to subsume the better known and more specifically defined construct under the rubric of the fuzzier construct. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
54.
The aim of the treatise is the proof of educational stays of Russian physicians at the university of Leipzig in the second
half of the 19th century. At that time famous scholars of the university of Leipzig like Carl Ludwig, Paul Flechsig,Wilhelm
His, Julius Cohnheim and Felix Marchand made an important contribution to the development of physiology, pathology, physiological
chemistry and pharmacology.Therefore their institutes were attended by many student trainees.Among them were a lot of Russian
physicians too.They went to Leipzig with fellowships from their government to prepare themselves for a professorship in Russia.
A bibliography of their experimental works is given.The findings are based on an investigation in German medical magazines.
Wir danken der Deutschen Forschungsgemeinschaft Bonn für die Unterstützung dieser Arbeit, die im Rahmen des Projektes ,,Deutsch-russische Beziehungen in Medizin und Naturwissenschaften im 18. und 19. Jahrhundert“ angefertigt wurde. 相似文献
Wir danken der Deutschen Forschungsgemeinschaft Bonn für die Unterstützung dieser Arbeit, die im Rahmen des Projektes ,,Deutsch-russische Beziehungen in Medizin und Naturwissenschaften im 18. und 19. Jahrhundert“ angefertigt wurde. 相似文献
55.
Gerhard Gries Keith N. Slessor Regine Gries Grigori Khaskin Priyantha D. C. Wimalaratne Tom G. Gray Gary G. Grant Alan S. Tracey Mike Hulme 《Journal of chemical ecology》1997,23(1):19-34
Three candidate sex pheromone components, (Z)6,(Z)9-, (Z)6,(E)8-, and (Z)6,(E)9-heneicosadien-11-one (Z6Z9, Z6E8, and Z6E9) were identified in pheromone gland extracts of female Douglas-fir tussock moths (DFTM), Orgyia pseudotsugata (McDunnough). Their occurrence in subnanogram quantities in extracts and structural conversion during analytical procedures and bioassays complicated chemical identifications. Complete identification required comparative analyses of stereoselectively synthesized and female-produced dienones by coupled gas chromatographic–electroantennographic detection (GC-EAD), high-performance liquid chromatography (HPLC) and coupled GC–mass spectrometry (MS). Determination of the pheromone component was contingent upon an experimental design that minimized structural rearrangement of dienones before and during the field test. In a 40-min field experiment, acetonitrile solutions of each of the above dienones were carried on Dry Ice to traps and were syringed onto cotton release devices below trap lids. In combination with the previously known sex pheromone component of DFTM, (Z)6-heneicosen-11-one (Z6), Z6E8 was the only synergistic dienone and the mixture was highly attractive. Because Z6 by itself attracts seven species of tussock moths (two sympatric with DFTM), a blend of Z6 and Z6E8 may impart specificity to DFTM pheromone communication. In commercial lures, this binary blend may facilitate species-specific, sensitive monitoring and efficacious control by mating disruption of this important forest defoliator. 相似文献
56.
R Regine A D'Agata P Nardi A Brettoni G Boncompagni SG Venezia 《Canadian Metallurgical Quarterly》1997,18(11-12):823-826
For its high incidence among young men and its affecting male fertility, varicocele requires an accurate screening, as well as an early and definitive treatment. The Authors report their experience in the treatment of varicocele with sclerotherapy: 24 patients underwent sclerotherapy of the left internal spermatic vein with a success rate of 91%. Complications never required hospitalization or surgery. Percutaneous therapy represents thus the treatment of choice in case of varicocele: compared with surgery, it offers similar clinical results and a lower recurrence rate, and it can be performed on an outpatient basis. Surgery should be performed only when anatomic variants make percutaneous treatment not feasible. 相似文献
57.
Gerhard Gries Jianxiong LI Regine Gries Wade W. Bowers Rick J. West Priyantha D. C. Wimalaratne Grigori Khaskin G. G. Skip King Keith N. Slessor 《Journal of chemical ecology》1994,20(1):1-8
(E)-11,13-Tetradecadienal (E11,13–14:Ald) is the major sex pheromone component of the eastern blackheaded budworm (EBB),Acleris variana (Fern.). The compound was identified in female pheromone gland extracts by coupled gas chromatographic-electroantennographic detection (GC-EAD), coupled GC-mass spectrometry in selected ion monitoring mode, and retention index calculations of candidate pheromone components.E11,13–14:Ald alone as trap bait was very attractive to male EBB. Addition of the corresponding diene alcohol or acetate or both did not enhance attraction. (Z)-11,13-Tetradecadienal in binary combination with (E)-11,13–14:Ald neither enhanced nor reduced trap catches. Increasing the amounts of pheromone from 0.01 to 10 µg increased trap catches, but increase of pheromone quantity above 100 µg proportionately reduced attraction. Stabilization of slowly polymerizingE11,13–14:Ald and development of a sustained, adequate release rate is required for pheromone-based monitoring of EBB populations. 相似文献
58.
Marc Rhainds Gerhard Gries Jianxiong Li Regine Gries Keith N. Slessor Carlos M. Chinchilla A. Cameron Oehlschlager 《Journal of chemical ecology》1994,20(12):3083-3096
Gas chromatographic-electroantennographic detection (GC-EAD) analyses of pheromone extract of female bagworms,Oiketicus kirbyi (Guilding), revealed five EAD-active compounds. Retention index calculations, GC-mass spectrometry in both full-scan and selected-ion monitoring modes and GC-EAD analyses of authentic standards identified the compounds as 1-methylbutyl octanoate (MBO), 1-methylbutyl nonanoate (MBN), 1-methylbutyl decanoate (MBD), 1-methylpentyl decanoate (MPD), and 1-methylbutyl dodecanoate (MBDD). Of these five chiral esters, MBD was most abundant in extracts and elicited the strongest antennal response. In field experiments in Costa Rica, (R)-MBD attractedO. kirbyi males, whereas (S)-MBD in combination with (R)-MBD inhibited response.R but notS enantiomers of MBO, MBN, and MBDD strongly synergized attraction to (R)-MBD. (S)-MBO and (S)-MBDD were inactive, whereas (S)-MBN was inhibitory. (R)-, (S)- and racemic MPD were inactive. Blends of (R)-MBD in ternary combination with either (R)-MBO and (R)-MBN or (R)-MBN and (R)-MBDD were as attractive as the five-ester blend. Five- and four-ester blends were equally attractive, suggesting redundancy of pheromone components for attraction of males. The multiple sex pheromone component blend of chiral esters inO. kirbyi may have evolved to maintain species-specific communication in bagworm communities of tropical Americas. 相似文献
59.
We tested the hypothesis that males and females of the cherry bark tortrix (CBT), Enarmonia formosana, antennally perceive and behaviorally respond to volatiles from nonhost plants. Volatiles from flowering cherry trees, Prunus serrulata Kwanzan, and from nonhost trees, including trembling aspen, Populus tremuloides, grand fir, Abies grandis, Norway spruce, Picea abies, and Scots pine, Pinus sylvestris, were captured on Porapak Q and extracts analyzed by coupled gas chromatographic–electroantennographic detection (GC-EAD). Compounds that elicited responses from male and female antennae were identified by coupled GC–mass spectrometry (MS) and by comparative GC-MS and GC-EAD with authentic standards. In field cage and field experiments, nonanal from aspen trees and (±)--pinene from coniferous trees were effective in reducing captures of male CBT in pheromone-baited traps and deterring oviposition by female CBT on cherry blocks. Recognition of nonhost volatiles, such as nonanal and -pinene, may allow male and/or female CBT to avoid trees that provide inadequate concealment from predators during calling, resting, and copulation and that are unsuitable for oviposition and development of offspring. Nonhost volatiles may also be exploited for control of CBT by disrupting both mate- and host-finding. 相似文献
60.
Gries R Khaskin G Khaskin E Foltz JL Schaefer PW Gries G 《Journal of chemical ecology》2003,29(10):2201-2212
(6Z,9Z,11S)-6,9-Heneicosadien-11-ol (Z6Z9-11S-ol-C21) and (6Z,9Z,11R)-6,9-heneicosadien-11-ol (Z6Z9-11R-ol-C21) were identified as major sex pheromone components of female tussock moths, Orgyia detritaGuérin-Méneville (Lepidoptera: Lymantriidae), on the basis of (1) analyses of pheromone gland extracts of female O. detrita by coupled gas chromatographic-electroantennographic detection (GC-EAD) and GC mass spectrometry, and (2) field trapping experiments with synthetic standards. Z6Z9-11S-ol-C21 and Z6Z9-11R-ol-C21 in combination, but not singly, attracted significant numbers of male moths. Racemic Z6Z9-11-ol-C21 was more attractive than the 1:3.5 (R:S) blend ratio found in pheromone gland extracts from female moths. Lower and higher homologues of Z6Z9-11-ol-C21 were also detected in GC-EAD recordings of pheromone extracts, and the racemic compounds enhanced attractiveness of Z6Z9-11-ol-C21 in field experiments. Because of trace amounts of these homologues in extracts, their enantiomeric composition could not be determined. This is the first report of secondary alcohols as pheromone components in the ditrysian (advanced) Lepidoptera. 相似文献