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EBSD measurements were carried out on four different martensitic steels (T91, P92, EM10 and Eurofer) in various metallurgical conditions (nine different microstructural states). The usual orientation relationships (ORs) between the parent austenitic phase and the resulting martensite in martensitic steels are those of Nishiyama–Wassermann (NW) and Kurjumov–Sachs (KS). The present study first proposes a methodology based on the combined analysis of the misorientation distribution, the pole figures (PFs) and the angle/axis pairs. This methodology leads to the conclusion that neither NW nor KS relationships are able to account for all the features observed whatever the material under study. A third OR proposed by Greninger and Troiano (GT) proves to describe the relationship between austenite and ferrite in all four different martensitic steels much more accurately. 相似文献
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Maribel Hernández-Guerrero 《European Polymer Journal》2005,41(10):2264-2277
Comb polymers were prepared using the RAFT process via a Z-group approach. Trithiocarbonate RAFT agents were covalently bound to a polymer backbone via ester linkages. Two different types of comb polymer backbones were prepared, based on either modified cellulose or statistical poly(styrene-co-2-hydroxyethylmethacrylate) backbones. The subsequent polymerization of styrene from these multi-RAFT-functional backbones displayed some unusual kinetics with the rate of polymerization increasing concomitantly with the trithiocarbonate concentration. The molecular weight of each polystyrene branch increased with conversion, however, deviation from the theoretical molecular weight was detected. The polystyrene comb polymers were utilized in a casting process to prepare highly regular honeycomb structured porous films using breath figures. In general, the regularity was found to increase with increasing number of branches on a backbone and with increasing length of the polystyrene branch. 相似文献
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Wei Wang Can Du Xiaofan Wang Prof. Xiaohua He Prof. Jiaping Lin Lei Li Prof. Shaoliang Lin 《Angewandte Chemie (International ed. in English)》2014,53(45):12116-12119
Porous polymeric films are of paramount importance in many areas of modern science and technology. However, processing methods typically based on direct writing, imprint, and lithography techniques have low throughput and are often limited to specific fabricated shapes. Herein, we demonstrate the directional photomanipulation of breath figure arrays (BFAs) formed by an azobenzene‐containing block copolymer to address the aforementioned problems. Under the irradiation of linearly polarized light, the round pores in the BFAs were converted to rectangular, rhombic, and parallelogram‐shaped pores in 30 min, due to the anisotropic mass migration based on the photo‐reconfiguration of the azobenzene units. Through a secondary irradiation after rotating the sample by 90°, the transformed pores were apparently recovered. Therefore, this non‐contacted, directional photomanipulation technique in conjunction with breath figure processing opens a new route to nano/microporous films with finely tuned features. 相似文献
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Alberto S. de León Alexandra Muñoz‐Bonilla Marta Fernández‐García Juan Rodríguez‐Hernández 《Journal of polymer science. Part A, Polymer chemistry》2012,50(5):851-859
Polymeric films with porous structures and microsphere patterns were prepared by the method of breath figures, mixing poly(methyl methacrylate) (PMMA) and amphiphilic copolymers containing glucose moieties in their structure, glycopolymers. Statistical and block glycopolymers were used in a proportion of 10 wt %. The statistical glycopolymers were synthesized via conventional free radical copolymerization, whereas the block copolymer of methyl methacrylate and 2‐{[(D ‐glucosamin‐2‐Nyl) carbonyl]oxy}ethyl methacrylate, PMMA‐b‐PHEMAGl, was obtained by atom transfer radical polymerization. Glycopolymers were blended with a high molecular weight PMMA matrix and dissolved in a mixture of tetrahydrofuran and a small amount of water. Results showed that, depending on experimental conditions (water content, humidity, and type of copolymer), the observed final film morphology changes significantly. Thus, films with honeycomb pattern structures, spherical particles, or a mixture of both were obtained. In addition, polar glucose moieties were oriented principally either inside of the pores in the case of films and towards the surface in the case of particles. The specific surface bioactivity of these materials was examined using the specific lectin concanavalin A conjugated with fluorescein, Con A‐FITC. The successful binding of the Con A was demonstrated by fluorescence microscopy being more intense at the surface of the pores and of the particles. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
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The predawn of paper chromatography 总被引:1,自引:0,他引:1
L. S. Ettre 《Chromatographia》2001,54(5-6):409-414
Summary The activities of F.F. Runge, F. Goppelsroeder and R.E. Liesegang are outlined. The technique of capillary analysis is described
and its shortcomings elaborated. Tswett's use of filter paper to imitate plant tissues is explained and finally, the considerations
of Izmailov and Shraiber eventually leading to thin-layer chromatography are summarized. 相似文献
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EquivalenceRelationsfromaGeometricalPointofView¥ChenZhengting(LuoyangEducationalInstitute)Abstract:WeProveatheoremaboutthegeo... 相似文献