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61.
We shall show how the nilpotency class of a finite loop Q is determined by the properties of a nilpotent inner mapping group. We also show that a classical result by Baer on the structure
of abelian finite capable groups holds for Moufang loops of odd order. 相似文献
62.
Oscar Picazo Ibon Alkorta José Elguero Markku R. Sundberg Jaana Valo Krzysztof Zborowski 《Structural chemistry》2009,20(4):557-563
A computational study of square planar organometallic complexes formed by the ligand 2,2′-bipyridine and all its possible
difluoro derivatives in analogous position of the aromatic rings (n,n′-difluoro-2,2′-bipyridine, where n = n′ = 3, 4, 5, and 6) and two M–X2 (M = Pd and Pt and X = F, Cl, Br, and I) fragments has been carried out amounting to a total of 80 complexes. Relationships
have been found between the chiral distinction energy and the different chemical moieties present. Using the statistical Free-Wilson
method, the relative energies between the diastereomeric complexes have been correlated with the position of the substituent,
the counter anion, and the central metal cation. 相似文献
63.
A study of 1-hexene polymerization with ethylene-bis(9-fluorenyl) hafnium dichloride has been carried out using two different cocatalyst systems, methyl-aluminoxane/trimethylaluminum (MAO/TMA) and tris-isobutyl-aluminum/N,N-dimethylanilinium tetrakis(pentafluorophenyl) borate (TIBA/borate). When MAO/TMA was used, 1-hexene polymerized into a low molar mass poly(1-hexene) with low catalytic activity. Activation with TIBA/borate increased polymerization activity drastically as well as the molar mass of the polymers. In order to analyze differences in the activity profiles, UV-Vis spectroscopy was employed to investigate ligand to metal charge transitions (LMCT) of the hafnocene dichloride during the activation process. The low catalytic activity and the fast chain transfer to the cocatalyst with MAO/TMA may originate from strong bonding between the metallocene cation and the MAO/TMA species thus obstructing monomer coordination and insertion. 相似文献
64.
Erkki Aitola Arto Puranen Harri Setl Sami Lipponen Markku Leskel Timo Repo 《Journal of polymer science. Part A, Polymer chemistry》2006,44(22):6569-6574
Vinylcyclohexane (VCH) was copolymerized with ethene and propene using methylaluminoxane‐activated metallocene catalysts. The catalyst precursor for the ethene copolymerization was rac‐ethylenebis(indenyl)ZrCl2 ( 1 ). Propene copolymerizations were further studied with Cs‐symmetric isopropylidene(cyclopentadienyl)(fluorenyl)ZrCl2 ( 2 ), C1‐symmetric ethylene(1‐indenyl‐2‐phenyl‐2‐fluorenyl)ZrCl2 ( 3 ), and “meso”‐dimethylsilyl[3‐benzylindenyl)(2‐methylbenz[e]indenyl)]ZrCl2 ( 4 ). Catalyst 1 produced a random ethene–VCH copolymer with very high activity and moderate VCH incorporation. The highest comonomer content in the copolymer was 3.5 mol %. Catalysts 1 and 4 produced poly(propene‐co‐vinylcyclohexane) with moderate to good activities [up to 4900 and 15,400 kg of polymer/(mol of catalyst × h) for 1 and 4 , respectively] under similar reaction conditions but with fairly low comonomer contents (up to 1.0 and 2.0% for 1 and 4 , respectively). Catalysts 2 and 3 , both bearing a fluorenyl moiety, gave propene–VCH copolymers with only negligible amounts of the comonomer. The homopolymerization of VCH was performed with 1 as a reference, and low‐molar‐mass isotactic polyvinylcyclohexane with a low activity was obtained. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6569–6574, 2006 相似文献
65.
Natalia Tong-Ochoa Kari Kopra Markku Syrjänpää Nicolas Legrand Harri Härmä 《Analytica chimica acta》2015
Protein post-translational modifications (PTMs) are regulatory mechanisms carried out by different enzymes in a cell. Kinase catalyzed phosphorylation is one of the most important PTM affecting the protein activity and function. We have developed a single-label quenching resonance energy transfer (QRET) assay to monitor tyrosine phosphorylation in a homogeneous high throughput compatible format. Epidermal growth factor receptor (EGFR) induced phosphorylation was monitored using Eu3+-chelate labeled peptide and label-free phosphotyrosine specific antibody in presence of a soluble quencher molecule. In the QRET kinase assay, antibody binding to phosphorylated Eu3+-peptide protects the Eu3+-chelate from luminescence quenching, monitoring high time-resolved luminescence (TRL) signals. In the presence of specific kinase inhibitor, antibody recognition and Eu3+-chelate protection is prevented, allowing an efficient luminescence quenching. The assay functionality was demonstrated with a panel of EGFR inhibitors (AG-1478, compound 56, erlotinib, PD174265, and staurosporine). The monitored IC50 values ranged from 0.08 to 155.3 nM and were comparable to those found in the literature. EGFR activity and inhibition assays were performed using low nanomolar enzyme and antibody concentration in a 384-well plate format, demonstrating its compatibility for high throughput screening (HTS). 相似文献
66.
Markku Niemenmaa 《Monatshefte für Mathematik》1986,101(3):183-191
We say that a near-ring (N,+,·) has an almost trivial multiplication (ATM) if the product of two elements belongs to the intersection of the additive cyclic groups generated by these two elements. We show that every finite near-ring with ATM can be decomposed to a direct sum where the summands are either near-rings defined on cyclic groups or near-rings whose minimal ideals are zero near-rings. Finally, we show how to construct these summands on cyclic groups. 相似文献
67.
Henna Elfström Markku Kuittinen Bernd H. Kleemann Ralf Arnold 《Optics Communications》2006,266(2):697-703
Area-coded effective medium structures (ACES) are a recently presented novel type of diffractive structure. Because of their higher stability compared to 2D binary blazed gratings, they have the potential of a broader use in micro-optics applications. The first fabrication with electron-beam lithography validate the theoretical model of blazed ACES. The measured diffraction efficiencies are in very good agreement with the values obtained from rigorous electromagnetic analysis. 相似文献
68.
Antero Aspiala Timo Lotta Juhani Murto Markku Rāsānen V.P. Gupta 《Chemical physics letters》1984,109(2):179-183
2-chloroallyl alcohol has been studied in low-temperature Ar, Kr, Xe, N2 and CH4 matrices. An IR-induced process was found in all media except CH4 and resulted in a steady state dependent on the Wavelength of the irradiation. At elevated temperatures thermal conformer interconversions occurred. The energetics of the processes are discussed and their potential barriers determined. No mode selectivity was found. 相似文献
69.
Edyta Piskorska Krystyna Lawniczak-Jablonska Iraida N. Demchenko Ewa Benko Markku Heinonen 《Mikrochimica acta》2004,145(1-4):159-163
X-ray photoelectron spectroscopy (XPS) is used to estimate phase and element contents of the composites based on cubic boron nitride. A composite is a mixture of several compounds and the use of traditional X-ray diffraction for phase analysis in many cases can be difficult. By using XPS, we were able to evaluate the atomic concentration of elements and the content of different compounds of each element. SEM and XPS showed that samples are heterogeneous. The TiB2 phase, expecting from thermodynamic calculations, was formed in both investigated samples of cBN/Ti3SiC2/TiC but in different amount. The Ti3SiC2 additive was found more chemically active then TiC. 相似文献
70.
Markku S. Hannula 《ZDM》2007,39(3):197-203
Since the 1990s there has developed a strong cluster of research around the affect in mathematics in Finland. This review highlights some outcome of this work. It is argued that both theoretically and methodologically there has been a tendency to incorporate influences from several sources, which has provided a fertile ground for innovative research. Some of the empirical findings are also reviewed. 相似文献