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131.
Using the thermodynamical approach and the method of York, the back-reaction of anti-de Sitter Schwarzschild black hole in thermal equilibrium with conformal spin-2 field is studied. It is found that both approaches give identical results. 相似文献
132.
Kojima T. Inoue E. Tsuchiya M. Ishimaru K. 《Journal of Thermal Analysis and Calorimetry》2003,72(2):737-742
TG, swelling, and viscometric studies are presented for the residues, PTHF/IPDI polymer networks, and the extracts, the linear
polymers and unreacted IPDI, after Soxhlet extraction of PTHF/IPDI reaction products. The products are obtained by reacting
PTHF with 650, 1400, (2×650+1×2900), or 2900 of molecular mass with IPDI at various concentrations in bulk. The results on
the swelling and the viscosity experiments suggest that the PTHF/IPDI reaction products have a usual expectable structure.
All the TG curves are a double stage curve. The initial stage and the last stage seem to reflect decomposition of PTHF chains
and vaporization of the remainder, IPDI, respectively. These are analyzed by a trial-and-error construction, supposing double
event behavior. The values of ratio of mass loss associated with the initial event, W01, to the mass loss associated with the last event, W02, are smaller than the expectable those. This suggests that Event 2 involves vaporization of the decomposition products of
PTHF moieties bonded to IPDI in addition to vaporization of IPDI.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
133.
《Tetrahedron letters》2003,44(40):7411-7415
The first total synthesis of two E type I phytoprostanes from furan, azelaic acid monomethyl ester and rac-1,2-epoxybutane is described. The key features of our synthetic strategy encompass an enzymatic kinetic resolution of a hydroxycyclopentenone, a Co-salen hydrolytic kinetic resolution of a terminal epoxide and a tandem conjugate addition/diastereoselective protonation sequence to construct the protected phytoprostanes. Mild cleavage of the silyl protective groups followed by enzymatic ester hydrolysis afforded the free E-type phytoprostanes. 相似文献
134.
The paper deals with a singularly perturbed reaction diffusionmodel problem. The focus is on reliable a posteriori error estimatorsfor the H1 seminorm that can be applied to anisotropic finiteelement meshes. A residual error estimator and a local problemerror estimator are proposed and rigorously analysed. They arelocally equivalent, and both bound the error reliably. Threemodifications of these estimators are introduced and discussed. Much attention is given to the performance of the error estimatorin numerical experiments. This helps to identify those estimatorsthat are suitable for practical applications. 相似文献
135.
CunLiuZHOU YuQingZHOU ZhiYongWANG 《中国化学快报》2003,14(4):355-358
The chemoselective addition of aldehydes in aquoues medium was obtained under mild condition using improved Henry reaction. 相似文献
136.
137.
DEBACHE Abdelmadjid BOULCINA Raouf TAFER Radia BELFAITAH Ali RHOUATI Salah CARBONI Bertrand 《中国化学》2008,26(11):2112-2116
The synthesis of 1,2,3,4-dihydropyrimidinone/thione derivatives was achieved in good to excellent yields using calcium(II) nitrate as catalyst to promote the Biginelli three-component condensation reaction from a diversity of aromatic aldehydes, β-keto compounds and urea or thiourea. The reaction was carried out under solvent-free conditions. 相似文献
138.
Taking both the heterogeneous catalytic processes, including the surface formation of particles with excited internal degrees of freedom, and the processes of multicomponent diffusion and heat transfer in the MESOX apparatus fully into account makes it possible to obtain a recombination coefficient and an accommodation coefficient of the oxygen-atoms-on-quartz recombination energy which are in good agreement with the experimental data. The heterogeneous catalysis model constructed can be used effectively for predicting the heat fluxes to the surface of reentry vehicles on their entry into the Earth’s atmosphere. 相似文献
139.
140.
A general and controlled bidirectional growth strategy enable a very rapid and efficient construction of oligo(phenyleneethynylene)s possessing functional groups such as methylthio and thioacetate groups at both ends. The strategy employs only one reaction type with good to moderate yields to grow the conjugated chains. The synthesis is efficient and can give 23 benzene rings and 22 carbon-carbon triple bonds in the conjugated chains. The compounds are fully characterized by 1H and 13C NMR and UV/vis and fluorescence spectroscopy. 相似文献