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991.
Aamer Saeed 《Chemistry of Heterocyclic Compounds》2007,43(8):1072-1075
An efficient, rapid, microwave-accelerated one-step synthesis of some 5-aryl-2-(2-hydroxy-phenyl)-1,3,4-oxadiazoles by reaction
of salicylic hydrazide with carboxylic acids in the presence of thionyl chloride under neat conditions is described.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1264–1267, August, 2007. 相似文献
992.
Kobayashi S Miyamura H Akiyama R Ishida T 《Journal of the American Chemical Society》2005,127(25):9251-9254
A novel, highly active immobilized ruthenium catalyst, which can be successfully used in oxidation of alcohols to aldehydes and ketones, has been developed. In contrast to most immobilized catalysts, the Ru catalyst has activity that is higher than that of the original non-immobilized catalyst. In a batch system, the Ru catalyst was recovered and reused several times without loss of activity. The catalyst was also applied to a flow system, in which excellent conversions and yields were demonstrated. No leaching of Ru was observed in both cases. 相似文献
993.
Hiroyoshi Kamogawa Hiroyuki Kohno Rikiya Kitagawa 《Journal of polymer science. Part A, Polymer chemistry》1989,27(2):487-495
Polymerizable carbamates were synthesized from 3-vinylphenyl and 2-methacryloyloxyethyl isocyanates and perfume and herbicide alcohols, such as 2-phenethyl alcohol, citronellol, geraniol, 1-menthol, borneol, and 2-(2,4-dichlorophenoxy)- and 2-(2,4,5-trichlorophenoxy)ethyl alcohols. Copolymerization of these carbamate monomers and N-vinyl-2-pyrrolidone with AIBN in dioxane gave respective copolymers. Hydrolyses of both monomers and copolymers, however, required severe acid conditions, although different chemical structures gave different hydrolytic behaviors. 相似文献
994.
The relativistic ground and low-lying excited state potential energy curves of AgH and AuH in the presence of a cylindrical
harmonic confining potential were calculated using the multi-state multi-reference perturbation theory with the spin-free
no-pair Hamiltonian obtained via the third-order Douglas–Kroll transformation, incorporated with the full two-electron Breit–Pauli
spin–orbit operator. The spectroscopic parameters were obtained for both the scalar- and quasi-relativistic potentials. The
spin–orbit coupling constants were calculated for several strengths of the confining potential, and the effects of the applied
potential on the coupling constants were analyzed using configuration interaction.
This paper is dedicated to Serafín Fraga—colleague, mentor, and friend. 相似文献
995.
The boundary effect on the drag on two identical, nonuniformly structured flocs moving along the axis of a cylindrical tube
filled with a Newtonian fluid is investigated at a small to medium larger Reynolds number. A two-layer model is adopted to
simulate various possible structures of a floc, and the flow field inside is described by Darcy–Brinkman model. The results
of numerical simulation reveal that a convective flow is present in the rear region of a floc when Reynolds number is on the
order of 40. The presence of the tube wall and/or the porous structure of a floc has the effect of reducing that convective
flow. For a fixed level of the volume-average permeability of a floc, the influence of the tube wall on the drag depends upon
floc structure; the influence on a nonuniformly structured floc is more significant than that on a uniformly structured floc.
The more nonuniform the floc structure, the more appreciable the deviation of the drag coefficient–Reynolds number curve from
a Stokes’-law-like relation becomes. The smaller the volume-average permeability of a floc and/or the smaller the separation
distance between the two flocs, the greater is the deviation, but the presence of the tube wall has the effect of reducing
that deviation. 相似文献
996.
In order to investigate the reason why phenylpropanoic acid derivative (KCL), a potent, human peroxisome proliferator-activated receptor (PPAR) alpha-selective agonist, shows this selectivity, we analyzed the binding modes of KCL and a related compound to the ligand-binding domain of human PPARalpha and rat PPARalpha by means of computer-aided molecular modeling. We concluded that the characteristic specificity of KCL is due to a specific hydrophobic contact between the hydrophobic tail part (the 4-trifluoromethyl group) and the key amino acid Ile272 located on the helix three region of the human PPARalpha ligand binding domain. We propose a possible binding mode of KCL with the ligand-binding domain of human PPARalpha. This binding model should offer important insights for further structural design of subtype-selective PPARalpha agonists for the treatment of altered metabolic homeostasis, such as dyslipidemia, obesity, and diabetes. 相似文献
997.
Eigoro Murayama Masahiro Uematsu Hiroyuki Nishio Tadashi Sato 《Tetrahedron letters》1984,25(3):313-316
Internal reaction of secondary alkyltin(IV) compounds having thionium ion gave internal trans olefins with high yield and regio- and stereoselectivity via 1,5- or 1,6-transfer of a hydride β to the trialkylstannyl group. 相似文献
998.
Antonio Doménech María Teresa Doménech-Carbó María Luisa Vázquez de Agredos Pascual 《Journal of Solid State Electrochemistry》2007,11(9):1335-1346
The preparation of indigo from Indigofera suffruticosa following the procedures attributed to ancient Mayas was electrochemically monitored using the voltammetry-of-microparticles
approach. The mechanism formation of indigotin and indirubin from its precursors, indican and isatan, is discussed. Comparison
of voltammetric profiles for differently prepared and commercial indigos and genuine Maya Blue samples suggests that the preparation
procedure of indigo changed during the Late Classical Maya period.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
999.
JongHwa Moon SangHoon Kang YongSam Chung OkHee Lee 《Journal of Radioanalytical and Nuclear Chemistry》2007,271(1):155-158
Instrumental neutron activation analysis was used to assess the concentration of the inorganic trace elements in Korean women’s
blood serums. It was found that a high concentration of Na and Cl incurs an analytical interference, but the 12 elements such
as Br, Ca, Cl, Co, Cr, Cs, Fe, K, Na, Rb, Se and Zn could be determined under the condition of an interference minimization.
Serum samples collected from 63 women were analyzed and the concentration level and range of the elements were evaluated.
NIST SRMs were analyzed simultaneously for quality control. The average values of the Na and Cl determined in the serum samples
were 3,365 and 3,533 mg/l, Ca was 96.4 mg/l and K was 191 mg/l. Besides, Br, Se and Zn have a concentration level of 6.46,
0.13 and 0.98 mg/l, respectively. It was found that there is no significant difference between the present values and the
reported values. 相似文献
1000.
Rasa Pauliukaite Mariana Emilia Ghica Madalina Barsan Christopher M. A. Brett 《Journal of Solid State Electrochemistry》2007,11(7):899-908
The polymer redox mediator, poly(neutral red) (PNR), has been synthesised and characterised electrochemically to investigate
the best electropolymerisation and mediation conditions for application in enzyme biosensors and to clarify the mechanism
of action. Neutral red was electropolymerised by potential cycling on carbon film electrode substrates by allowing the monomer
to be oxidised during the full 20 cycles of polymerisation or reducing the positive limit of the potential window after the
first 2 cycles to impede monomer oxidation with a view to obtaining longer polymer chains and a lesser degree of branching.
Comparison was made with glassy carbon substrates. The PNR films on carbon film electrodes were characterised using cyclic
voltammetry and electrochemical impedance spectroscopy, as well as in glucose biosensors prepared with PNR. Glucose oxidase
enzyme was immobilised by encapsulation in silica sol-gel and compared with that obtained by cross-linking with glutaraldehyde.
The biosensors were evaluated by chronoamperometry in 0.1 M phosphate buffer saline solution, pH 7.0, and showed evidence
of electron transfer between the enzyme cofactor flavin adenine dinucleotide and PNR dissolved in the enzyme layer competing
with PNR-mediated electrochemical degradation of H2O2 formed during the enzymatic process.
This paper is dedicated to Professor Dr. Algirdas Vaskelis on the occasion of his 70th birthday. 相似文献