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  • Anomalousparticle  (2)
  • EXAFS  (2)
  • Mitochondrial DNA  (2)
  • Springer  (6)
  • American Association for the Advancement of Science (AAAS)
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  • Springer  (6)
  • American Association for the Advancement of Science (AAAS)
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  • 1
    Electronic Resource
    Electronic Resource
    Ship-in-Bottle synthesis of Pt9-Pt15 carbonyl clusters inside NaY and NaX zeolites, in-situ FTIR and EXAFS characterization and the catalytic behaviors in13CO exchange reaction and NO reduction by CO (1992)
    Springer
    Catalysis letters 12 (1992), S. 171-185 
    Details
    ISSN: 1572-879X
    Keywords: Ship-in-Bottle synthesis ; Pt carbonyl clusters ; NaY zeolites ; EXAFS ; 13CO exchange ; NO + CO reaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract [Pt9(CO)18]2−/NaY (orange-brown, 2056 and 1798 cm−1), [Pt12(CO)24]2−/NaY (dark-green, 2080 and 1824 cm−1 and [Pt15(CO)30]2−/NaX (yellow-green, 2100 and 1865 cm−1) were stoichiometrically synthesized by the reductive carbonylation of [Pt(NH3)4]2+/NaY, Pt2+/NaY and Pt2+/NaX, respectively. The IR bands characteristic of their linear carbonyls shift to higher frequencies whereas the bridging CO bands to lower frequencies, compared with those on the external zeolites and in solution. In-situ FTIR studies suggested that the subcarbonyl species such as PtO(CO) and “Pt3(CO)3(μ2 −CO)3” are formed as the proposed intermediates towards [Pt12(CO)24]2−/NaY in the reductive carbonylation of Pt2+/NaY.13CO exchange reaction preceded with the different intrazeolite Pt carbonyl species in the following order of activity at 298–343 K: “Pt3(CO)3(μ2 –CO)3”/NaY ≫ PtO(CO)/NaY〉[Pt9(CO)18]2−/NaY 〉[Pt12(CO)24]2−/NaY. Pt-L3-edge EXAFS measurment for these synthesized samples demonstrated that they are consistent with the Pt carbonyl clusters having trigonal prismatic Pt9 and Pt12 frameworks infered to a series of the Chini complexes such as [NEt4]2[Pt3(CO)6] n ( n = 3–5). The intrazeolite Pt9 and Pt12 carbonyl clusters exhibited higher cataytic activity in NO reduction by CO towards N2 and N2O at 473 K, compared with those on the conventional Pt/Al2O3 catalysts. The mechanism of intrazeolite Pt9-Pt15 carbonyl cluster formation are discussed in terms of the intrazeolite basicity and acidity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00767199
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  • 2
    Electronic Resource
    Electronic Resource
    EXAFS and FTIR characterization of tetrarhodium carbonyl clusters attached on tris-(hydroxymethyl)phosphine grafted silica catalytically active for olefin hydroformylation (1993)
    Springer
    Catalysis letters 20 (1993), S. 37-48 
    Details
    ISSN: 1572-879X
    Keywords: Attached Rh4 clusters ; phosphine-modified SiO2 ; EXAFS
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The structure of the cluster framework in Rh4(CO)12 attached on tris-(hydroxy-methyl)phosphine (P(CH2OH)3,THP) modified SiO2 was studied by EXAFS and IR spectroscopies in conjunction with their catalytic activities and selectivities for the olefin hydroformylation reaction. Rh4(CO)12 was attached on THP/SiO2 by phosphine substitution with remaining Rh4 framework (Rh4/THP/SiO2), which gives the IR bands at 2068, 2044 cm−1 and 1870, 1840 cm−1 due to the linear and bridge CO of the Rh4 clusters. EXAFS study suggested that Rh4 clusters on THP/SiO2 were coordinated by two adjacent phosphine ligands of THP/SiO2 and that the Rh4 framework was fairly distorted. The Rh-Rh distance of Rh4/THP/SiO2 was 0.05 Å longer than that of Rh4(CO)12 crystal. Rh4/THP/SiO2 exhibited the selective formation of propanal in the gas phase hydroformylation of ethene under mild conditions (〉98% of propanal formation in 300–373 K, 40 kPa). In contrast, the attached Rh6(CO)16, [Rh(CO)2Cl]2 on THP/SiO2 and Rh4(CO)10(THP)2 on SiO2 were not active for the hydroformylation, which implies that the distorted Rh4 clusters attached on THP/SiO2 are catalytically active and selective towards aldehydes in the olefin hydroformylation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00772595
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  • 3
    Electronic Resource
    Electronic Resource
    Transfer of the CMS trait in Daucus carota L. by donor-recipient protoplast fusion (1988)
    Springer
    Theoretical and applied genetics 76 (1988), S. 855-860 
    Details
    ISSN: 1432-2242
    Keywords: Daucus carota L. ; Cytoplasmic male sterility ; Donor-recipient protoplast fusion ; Cybrids ; Mitochondrial DNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary X-irradiated protoplasts of Daucus carota L., 28A1, carrying cytoplasmic male sterile (CMS) cytoplasm and iodoacetamide-treated protoplasts of a fertile carrot cultivar, ‘K5’, were fused with polyethylene glycol (PEG), and 73 plants were regenerated. Twenty-six randomly chosen regenerated plants had non-parental mitochondrial DNA (mtDNA) as revealed by XbaI restriction fragment patterns, and all of the plants investigated had diploid chromosome numbers. Of the 11 cybrid plants that showed mtDNA fragment patterns clearly different from those of the parents, 10 plants showed male sterility with brown or red anthers, and one plant possessed partially sterile yellow anthers. The mtDNA fragment patterns of the ten cybrid plants with male sterile flowers resembled that of a CMS parent, 28A1; and four fragments were identified that were common between the sterile cybrid plants and 28A1, but absent from the partially sterile cybrid plants and a fertile cultivar, ‘K5’. The results indicated that the CMS trait of the donor was efficiently transferred into the cybrid plants by donor-recipient protoplast fusion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00273672
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  • 4
    Electronic Resource
    Electronic Resource
    Mitochondrial genome diversity among cultivars of daucus carota (ssp. sativus) and their wild relatives (1989)
    Springer
    Theoretical and applied genetics 77 (1989), S. 39-43 
    Details
    ISSN: 1432-2242
    Keywords: Daucus ; Carrot ; Mitochondrial DNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Restriction fragment patterns of mitochondrial DNAs (mtDNAs) from 13 carrot cultivars (Daucus carota ssp. sativus), wild carrot (ssp. carota), ssp. gummifer, and D. capillifolius were compared with each other using four restriction endonucleases. The mtDNAs of the 13 carrot cultivars could be classified into three distinct types — I, II and III — and were also clearly distinguishable from the mtDNAs of wild carrot (type IV), gummifer (V) and D. capillifolius (VI). The proportions of common restriction fragments (F values) shared by two of the three mtDNA types (I, II and III) of carrot cultivars were approximately 0.5–0.6. The F values were 0.4–0.5 for mitochondrial genomes between wild carrot, ssp. gummifer and D. capillifolius. The mitochondrial genomes between wild carrot and the carrot cultivars showed closer homologies those between wild carrot, ssp. gummifer, and D. capillifolius. The diversity of the mitochondrial genomes among the carrot cultivars is too high to presume that it was generated from the cytoplasm of only one common ancestor during the relatively short history of carrot breeding. These results suggested that the three types of cytoplasms found in the carrot cultivars might have existed in a prototype of D. carota in pre-historical times.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00292313
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  • 5
    Electronic Resource
    Electronic Resource
    Production of anomalous polymer microspheres having uneven surfaces by “stepwise” heterocoagulation technique (1990)
    Springer
    Colloid & polymer science 268 (1990), S. 791-796 
    Details
    ISSN: 1435-1536
    Keywords: Anomalousparticle ; microsphere ; emulsionpolymerization ; emulsionblend ; heterocoagulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Anomalous polymer microspheres having uneven surfaces were produced by “stepwise” heterocoagulation technique of small polymer particles (SPs) onto large polymer particles (LPs).SPs andLPs have surface charges opposite to each other in the emulsion states.SPs were produced by emulsion copolymerization of styrene and methacryloyloxyethyltrimethylammonium chloride, andLPs by emulsion terpolymerization of styrene, butyl acrylate and methacrylic acid, with nonionic emulsifier being used in both cases. Maximum covering ofLP bySPs was obtained under the conditions that both emulsions were blended without the coagulation at pH 3 at room temperature and then left stand to coagulate with each other at 70 °C for 4 h at pH 9.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01410956
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  • 6
    Electronic Resource
    Electronic Resource
    Analysis of ″stepwise″ heterocoagulation process of small cationic polymer particles onto large anionic polymer particles using dynamic light scattering (1991)
    Springer
    Colloid & polymer science 269 (1991), S. 125-130 
    Details
    ISSN: 1435-1536
    Keywords: Anomalousparticle ; dynamiclight-scattering ; emulsionblend ; emulsionpolymerization ; heterocoagulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract In order to clarify in detail the process of the “stepwise” heterocoagulation of small polymer particles (SP) onto large polymer particles (LP), which we proposed to prepare anomalous polymer particles, the particle-size distribution in each step was estimated using dynamic light scattering.SP andLP have surface charges opposite to each other in emulsion states.SP were produced by emulsion copolymerization of styrene and methacryloyloxyethyltrimethylammonium chloride, andLP by emulsion terpolymerization of styrene, butyl acrylate, and methacrylic acid. Both emulsions in which nonionic emulsifier had been added were blended without coagulation and then the heterocoagulation was carried out by adjusting of the pH and heating.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00660301
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