ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Electronic structures of new π-conjugated cyclic polymers with quinoid structures (1995)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 103 (1995), S. 1871-1877 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Geometrical and electronic structures of new π-conjugated five-membered ring polymers were theoretically investigated. These polymers are analogous to heterocyclic polymers, but adopt as bridging groups (approximately-greater-than)CH2, (approximately-greater-than)CF2, (approximately-greater-than)SiH2, (approximately-greater-than)SiF2, (approximately-greater-than)C=CH2, (approximately-greater-than)C=O and (approximately-greater-than)C=S moieties instead of heteroatoms. The ground-state geometries of the polymers were predicted to be quinoid from semiempirical band calculations with AM1 Hamiltonian. The electronic properties of these systems were obtained using the modified extended Hückel method. The calculated band gaps (Eg) were analyzed in terms of geometrical relaxations and electronic effect of the bridging groups using the equation of Eg=ΔEδr+ΔE1–4+ΔEel. The effect of bond-length alternation (ΔEδr) amounts to 1.1–1.4 eV for the aromatic forms and 1.8–1.9 eV for the quinoid forms of the polymers. The interactions (ΔE1–4) between C1 and C4 atoms of the cis-PA type backbone tend to decrease the band gaps of the aromatic forms and to increase the gaps of the quinoid forms as much as 0.2–0.5 eV, depending on the size of a bridging atom. It is found that the electronic effect (ΔEel) of these bridging groups is quite small compared to that found in heterocyclic polymers such as polythiophene, polypyrrole, and polyfuran. ΔEel of (approximately-greater-than)CF2, (approximately-greater-than)SiH2, and (approximately-greater-than)SiF2 bridging groups are negligible and that of the other groups amounts to 0.3–1.0 eV. Therefore, the band gaps of these systems almost correspond to the ΔEδr values which arise from the bond-length alternations, except the case of the polymers with (approximately-greater-than)C=O and (approximately-greater-than)C=S bridging groups whose π* orbitals strongly interact with the π system of the polymeric backbone. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.469711
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Theoretical study of geometrical and electronic structures of new π-conjugated thiophene copolymers (1996)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 104 (1996), S. 1140-1146 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Theoretical work was performed to investigate the geometrical and electronic structures of four new hypothetical thiophene copolymers: poly(thienylene cyclopentadienylene) (PThPD), poly(thienylene silolylene) (PThS), poly(thienylene oxocyclopentadienylene) (PThOPD) and poly(thienylene thiocyclopentadienylene) (PThTPD). AM1 band calculations showed that the ground-state geometries of PThPD and PThS copolymers are of the aromatic forms whereas those of PThOPD and PThTPD are quinoid. Each intraring structure of the copolymers is predicted to be nearly identical to that of their corresponding parent homopolymers and the bond-length alternation (δr) of each copolymer is equal to the average of δr values for the two corresponding homopolymers. Modified extended Hückel band calculations produced that the band gaps (which correspond to the absorption peaks of π–π* band transition) of the copolymers in their ground states are 1.7 for PThPD, 1.55 for PThS, 1.9 for PThOPD, and 2.09 eV for PThTPD. These values, except for PThPD, are quite smaller than the band gaps calculated for the corresponding homopolymers in the ground states. Decomposition of the band gaps reveals that the gaps of the aromatic forms of PThPD and PThS are dominated by the δr contribution and the electronic effect of the bridging groups and that the gaps of the quinoid types of PThOPD and PThTPD correspond primarily to the δr contribution. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.470769
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Erratum: Theoretical study of geometrical and electronic structures of new π-conjugated thiophene copolymers [J. Chem. Phys. 104, 1140 (1996)] (1996)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 105 (1996), S. 1301-1301 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.473008
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Dissection of component QTL expression in yield formation in rice (2005)
    Oxford, UK : Blackwell Publishing Ltd
    Plant breeding 124 (2005), S. 0 
    Details
    ISSN: 1439-0523
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Yield and its components were investigated by using a population of 241 recombinant inbred lines (F9 RILs) derived from an elite hybrid rice cross of ‘Zhenshan 97’בMinghui 63′. Quantitative trait loci (QTLs) for causal analysing of yield traits were detected at different yield component (YC) influences by conditional and unconditional QTL mapping methods. The number of QTLs significantly affecting yield was different at component-special influence. Some QTLs controlling yield identified in one component influence were undetectable at the others. More QTLs for yield could be detected at different YC influences. It is possible to reveal that causal gene expression for yield could be different at different YC influences. Mapping QTLs for component effects of yield could help us in understanding the nature of cause-effect traits for the formation of grain yield.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1439-0523.2005.01093.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Analysis of embryo, endosperm, cytoplasmic and maternal effects for heterosis of protein and lysine content in indica hybrid rice (1999)
    Oxford, UK : Blackwell Publishing Ltd
    Plant breeding 118 (1999), S. 0 
    Details
    ISSN: 1439-0523
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: The heterosis controlled by genetic main effects and genotype × environment (GE) interaction effects for protein content and lysine content traits of indica hybrid rice, Oryza sativa L., was studied by using a genetic model for quantitative traits of triploid endosperm. The experiment was conducted over 2 years in a factorial design that included nine cytoplasmic male-sterile lines as females and five restorer lines as males. It was revealed that heterosis of protein content and lysine content were simultaneously controlled by genetic main effects and GE interaction effects. Maternal general heterosis and maternal interaction heterosis were observed. Embryo heterosis or cytoplasm heterosis for lysine content and endosperm heterosis for protein content were more important in general heterosis. Embryo interaction heterosis and cytoplasm interaction heterosis were more important for protein content, but endosperm heterosis was only important for lysine content in GE interaction heterosis. It was shown that some indica hybrid crosses had significant positive heterosis for protein content. Negative heterosis for lysine content was observed in most hybrid crosses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1439-0523.1999.00418.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    A method of choosing locations based on genotype × environment interaction for regional trials of rice (2001)
    Oxford, UK : Blackwell Publishing Ltd
    Plant breeding 120 (2001), S. 0 
    Details
    ISSN: 1439-0523
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: An ideal test location with particular environmental conditions should generate a relatively large genotype × environment interaction (GE) value in regional trials. A method of selecting test locations based on GE was proposed. Using the statistic Dj, the ranking of ability to discriminate the best genotypes for locations could be obtained. The locations among the group with the smallest Dj value were deleted from the whole set step by step, and the number of locations was reduced to a rational level at which most (over 85%) of the GE sum of squares of trials were maintained. A comparative evaluation based on data collected from Zhejiang Province (China) rice regional trials showed that the new method was more feasible than two other methods without loss of accuracy and reliability.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1439-0523.2001.00564.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Experimental infection of European crustaceans with white spot syndrome virus (WSSV) (2001)
    Oxford UK : Blackwell Science Ltd
    Journal of fish diseases 24 (2001), S. 0 
    Details
    ISSN: 1365-2761
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Eight European marine and freshwater crustaceans were experimentally infected with diluted shrimp haemolymph infected with white spot syndrome virus (WSSV). Clinical signs of infection and mortalities of the animals were routinely recorded. Diagnosis was by direct transmission electron microscopy (TEM), DNA hybridization (dot-blot and in situ hybridization) using WSSV probes and by PCR using WSSV specific primers. High mortality rates were noted between 7 to 21 days post-infection for Liocarcinus depurator, Liocarcinus puber, Cancer pagurus, Astacus leptodactylus, Orconectes limosus, Palaemon adspersus and Scyllarus arctus. Mortality reached 100%, 1 week post-infection in P. adspersus. When infection was successful, direct TEM observation of haemolymph revealed characteristic viral particles of WSSV, some observed as complete virions (enveloped), others as nucleocapsids associated with envelope debris. WSSV probes showed strong positive reactions in dot-blots and by in situ hybridization in sections and specific virus DNA fragments were amplified successfully with WSSV primers. White spot syndrome virus was pathogenic for the majority of the crustaceans tested. This underlines the epizootic potential of this virus in European crustaceans.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2761.2001.00302.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    New evidence on the earliest human presence at high northern latitudes in northeast Asia (2004)
    [s.l.] : Macmillian Magazines Ltd.
    Nature 431 (2004), S. 559-562 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The timing of early human dispersal to Asia is a central issue in the study of human evolution. Excavations in predominantly lacustrine sediments at Majuangou, Nihewan basin, north China, uncovered four layers of indisputable hominin stone tools. Here we report magnetostratigraphic results that ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/nature02829
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Earliest presence of humans in northeast Asia (2001)
    [s.l.] : Macmillian Magazines Ltd.
    Nature 413 (2001), S. 413-417 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The timing of the earliest habitation and oldest stone technologies in different regions of the world remains a contentious topic in the study of human evolution. Here we contribute to this debate with detailed magnetostratigraphic results on two exposed parallel sections of lacustrine ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/35096551
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Friedel-crafts acetylation of a (NiC"3N"2)-quasi-aromatic ring in a nickel(II) complex, Nioyl
    Amsterdam : Elsevier
    Inorganica Chimica Acta 191 (1992), S. 91-95 
    Details
    ISSN: 0020-1693
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/S0020-1693(00)80333-3
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...