Microwave-assisted synthesis of new 2-arylpyrimido[4′,5′:4,5]thiazolo[3,2-α]benzimidazol-4(3H)-ones from 3-aminothia- zolo[3,2-α]benzimidazol-2-earboxamide and aroyl halides in solvent-free condition is described. In comparison with classical conditions the reactions are faster and the yields are higher under microwave irradiation. 相似文献
A practical synthesis of a novel class of phosphine ligands, phosphino substituted N-aryl pyrroles (PAP ligands), has been developed. These ligands are applied in the palladium-catalyzed coupling of a variety of aryl and heteroaryl chlorides with phenylboronic acid showing exceedingly high turnover numbers at mild reaction temperatures and even at room temperature. 相似文献
A repairable-item provisioning system with two levels of repair is presented. Under the assumption that the machine time-to-failure and the repair times are exponentially distributed, a new algorithm is developed to compute the long-run average number of machines operating. Using the new algorithm we determine the optimal number of machines and repair channels at the two repair centres to minimize cost and meet a service-level constraint. The algorithm, which is based on Little's result in queueing theory and the theory of regenerative processes, is extremely efficient in terms of computer storage and execution time. 相似文献
This paper is devoted to the investigation of the perturbation problem of right (left) Browder linear relations and lower (upper) semi-Browder linear relations under commuting compact linear relations. Further, our results are used to show the invariance of Browder’s spectrum. 相似文献
Let R be a noncommutative prime ring, U be the left Utumi quotient ring of R, and k, m, n, r be fixed positive integers. If there exist a generalized derivation G and a derivation g (which is independent of G) of R such that [G(xm)xn + xng(xm), xr]k = 0, for all x ∈ R, then there exists a ∈ U such that G(x) = ax, for all x ∈ R. As a consequence of the result in the present article, one may obtain Theorem 1 in Demir and Argaç [10Demir, Ç., Argaç, N. (2010). A result on generalized derivations with Engel conditions on one-sided ideals. J. Korean Math. Soc. 47(3):483–494.[Crossref], [Web of Science ®], [Google Scholar]]. 相似文献
Among alternative techniques to overcome the difficulties associated with thermal regeneration, non-thermal plasma can be considered as one of the most promising technology. The coke trapped in the zeolite micropores can be oxidized at room temperature with a low energy consumption using a dielectric barrier discharge reactor with a pin to plate geometry. The influence of various experimental parameters for coke removal efficiency and ozone production was investigated: input power, gap between the two electrodes, gas flow rate, catalyst mass and compactness. We showed that the efficiency was not strongly increased by increasing the deposited power from 23 to 36 W, but it depends strongly on the mass, so the depth of the wafer. The elimination of coke becomes more difficult as soon as the compactness is increased. The removal of coke is not uniform within the wafer, the one localized into the depth of the wafer is difficult to remove and requires higher input power (>?30 W).
[Cd5(OH)(H2O)3][CH3CO2]9 crystallizes in the triclinic system, with the space group P
, a = 10.897(3) Å, b = 11.035(5) Å, c = 16.061(12) Å, = 96.83(7), = 95.31(8), = 118.22(6) and z = 2. Its structure has been determined using 9497 unique single crystal data. The final refinements let the agreement factors R1 and wR2(F2) converge to reach the respective values of 0.0548 and 0.0986. R1 = 0.0338 for the 7264 unique data with I > 2(I). [Cd5(OH)(H2O)3][CH3CO2]9 is a cadmium hydroxide acetate compound with a bi-dimensional structure in which hydrogen bonds insure cohesion between layers stacked along the [1
10] direction. The inorganic network is built up of layers constituted of CdO6 octahedra and CdO7 pentagonal bi-pyramids sharing edge or corner. 相似文献